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Enable asynchronous SCSI scanning and logging facility. #4

Merged
merged 1 commit into from
Jul 6, 2017
Merged

Enable asynchronous SCSI scanning and logging facility. #4

merged 1 commit into from
Jul 6, 2017

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xalius
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@xalius xalius commented Jul 6, 2017

Fix boot stalled with SCSI/UAS drives attached via USB by enabling asynchronous scanning and enable logging facility for further debugging.

@ayufan ayufan merged commit 0831fbb into ayufan-rock64:release-4.4 Jul 6, 2017
@xalius xalius deleted the fix-usb3-uas branch July 18, 2017 19:47
ayufan pushed a commit that referenced this pull request Aug 27, 2017
There's no need to take the rcu read lock when rounding rate.

This patch fixes the following BUG:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
in_atomic(): 0, irqs_disabled(): 0, pid: 153, name: kworker/u16:2
5 locks held by kworker/u16:2/153:
 #0:  ("%s"("devfreq_wq")){......}, at: [<ffffff80080b8cf4>] process_one_work+0x1c4/0x58c
 #1:  ((&(&devfreq->work)->work)){......}, at: [<ffffff80080b8cf4>] process_one_work+0x1c4/0x58c
 #2:  (&devfreq->lock){......}, at: [<ffffff80089534c8>] devfreq_monitor+0x28/0x8c
 #3:  (&vop->vop_lock){......}, at: [<ffffff80084c826c>] dmc_notifier_call+0x14/0x34
 #4:  (rcu_read_lock){......}, at: [<ffffff80089557f0>] rockchip_dmcfreq_target+0x0/0x2e0
CPU: 3 PID: 153 Comm: kworker/u16:2 Not tainted 4.4.77 #2573
Hardware name: Rockchip Sheep board (DT)
Workqueue: devfreq_wq devfreq_monitor
Call trace:
[<ffffff8008089930>] dump_backtrace+0x0/0x1c8
[<ffffff8008089b0c>] show_stack+0x14/0x1c
[<ffffff800839718c>] dump_stack+0x8c/0xac
[<ffffff80080c8d5c>] ___might_sleep+0x11c/0x128
[<ffffff80080c8ddc>] __might_sleep+0x74/0x84
[<ffffff8008c371a4>] mutex_lock_nested+0x4c/0x39c
[<ffffff80089458d8>] clk_prepare_lock+0x58/0xc8
[<ffffff8008946ec8>] clk_round_rate+0x34/0x94
[<ffffff800895589c>] rockchip_dmcfreq_target+0xac/0x2e0
[<ffffff80089533f4>] update_devfreq+0x100/0x1ac
[<ffffff80089534d0>] devfreq_monitor+0x30/0x8c
[<ffffff80080b8e1c>] process_one_work+0x2ec/0x58c
[<ffffff80080ba16c>] worker_thread+0x300/0x428
[<ffffff80080bf3e0>] kthread+0x104/0x10c
[<ffffff8008082840>] ret_from_fork+0x10/0x50

Change-Id: I31f75a55da72cab597796edd5c339222094fff97
Signed-off-by: Finley Xiao <finley.xiao@rock-chips.com>
ayufan pushed a commit that referenced this pull request Nov 26, 2017
There's a race between usb_gadget_udc_stop() which is likely
to set the gadget driver to NULL in the udc driver and this drivers
gadget disconnect fn which likely checks for the gadget driver to
a null ptr. It happens that unbind (doing set_gadget_data(NULL))
is called before the gadget driver is set to NULL and the udc driver
calls disconnect fn which results in cdev being a null ptr.

As a workaround we check cdev in android_disconnect() to prevent
the following panic:

Unable to handle kernel NULL pointer dereference at virtual address 000000a8
pgd = ffffff800940a000
[000000a8] *pgd=00000000be1fe003, *pud=00000000be1fe003, *pmd=0000000000000000
Internal error: Oops: 96000046 [#1] PREEMPT SMP
CPU: 7 PID: 1134 Comm: kworker/u16:3 Tainted: G S 4.9.41-g75cd2a0231ea-dirty #4
Hardware name: HiKey960 (DT)
Workqueue: events_power_efficient event_work
task: ffffffc0b5f4f000 task.stack: ffffffc0b5b94000
PC is at android_disconnect+0x54/0xa4
LR is at android_disconnect+0x54/0xa4
pc : [<ffffff8008855938>] lr : [<ffffff8008855938>] pstate: 80000185
sp : ffffffc0b5b97bf0
x29: ffffffc0b5b97bf0 x28: 0000000000000003
x27: ffffffc0b5181c54 x26: ffffffc0b5181c68
x25: ffffff8008dc1000 x24: ffffffc0b5181d70
x23: ffffff8008dc18a0 x22: ffffffc0b5f5a018
x21: ffffffc0b5894ad8 x20: 0000000000000000
x19: ffffff8008ddaec8 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000
x15: 0000000000000000 x14: 00000000007c9ccd
x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000001 x10: 0000000000000001
x9 : ffffff800930f1a8 x8 : ffffff800932a133
x7 : 0000000000000000 x6 : 0000000000000000
x5 : ffffffc0b5b97a50 x4 : ffffffc0be19f090
x3 : 0000000000000000 x2 : ffffff80091ca000
x1 : 000000000000002f x0 : 000000000000002f

This happened on a hikey960 with the following backtrace:

[<ffffff8008855938>] android_disconnect+0x54/0xa4
[<ffffff80089def38>] dwc3_disconnect_gadget.part.19+0x114.888119]
[<ffffff80087f7d48>] dwc3_gadget_suspend+0x6c/0x70
[<ffffff80087ee674>] dwc3_suspend_device+0x58/0xa0
[<ffffff80087fb418>] dwc3_otg_work+0x214/0x474
[<ffffff80087fdc74>] event_work+0x3bc/0x5ac
[<ffffff80080e5d88>] process_one_work+0x14c/0x43c
[<ffffff80080e60d4>] worker_thread+0x5c/0x438
[<ffffff80080ece68>] kthread+0xec/0x100
[<ffffff8008083680>] ret_from_fork+0x10/0x50

dwc3_otg_work tries to handle a switch from host to device mode
and therefore calls disconnect on the gadget driver.

To reproduce the issue it is enaugh to enable tethering (rndis gadget),
unplug and plug in again the usb connector which causes the change
from device to host and back to device mode.

Signed-off-by: Danilo Krummrich <danilokrummrich@gmail.com>
ayufan pushed a commit that referenced this pull request Dec 17, 2017
commit ab31fd0 upstream.

v4.10 commit 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN
recovery") extended accessing parent pointer fields of struct
zfcp_erp_action for tracing.  If an erp_action has never been enqueued
before, these parent pointer fields are uninitialized and NULL. Examples
are zfcp objects freshly added to the parent object's children list,
before enqueueing their first recovery subsequently. In
zfcp_erp_try_rport_unblock(), we iterate such list. Accessing erp_action
fields can cause a NULL pointer dereference.  Since the kernel can read
from lowcore on s390, it does not immediately cause a kernel page
fault. Instead it can cause hangs on trying to acquire the wrong
erp_action->adapter->dbf->rec_lock in zfcp_dbf_rec_action_lvl()
                      ^bogus^
while holding already other locks with IRQs disabled.

Real life example from attaching lots of LUNs in parallel on many CPUs:

crash> bt 17723
PID: 17723  TASK: ...               CPU: 25  COMMAND: "zfcperp0.0.1800"
 LOWCORE INFO:
  -psw      : 0x0404300180000000 0x000000000038e424
  -function : _raw_spin_lock_wait_flags at 38e424
...
 #0 [fdde8fc90] zfcp_dbf_rec_action_lvl at 3e0004e9862 [zfcp]
 #1 [fdde8fce8] zfcp_erp_try_rport_unblock at 3e0004dfddc [zfcp]
 #2 [fdde8fd38] zfcp_erp_strategy at 3e0004e0234 [zfcp]
 #3 [fdde8fda8] zfcp_erp_thread at 3e0004e0a12 [zfcp]
 #4 [fdde8fe60] kthread at 173550
 #5 [fdde8feb8] kernel_thread_starter at 10add2

zfcp_adapter
 zfcp_port
  zfcp_unit <address>, 0x404040d600000000
  scsi_device NULL, returning early!
zfcp_scsi_dev.status = 0x40000000
0x40000000 ZFCP_STATUS_COMMON_RUNNING

crash> zfcp_unit <address>
struct zfcp_unit {
  erp_action = {
    adapter = 0x0,
    port = 0x0,
    unit = 0x0,
  },
}

zfcp_erp_action is always fully embedded into its container object. Such
container object is never moved in its object tree (only add or delete).
Hence, erp_action parent pointers can never change.

To fix the issue, initialize the erp_action parent pointers before
adding the erp_action container to any list and thus before it becomes
accessible from outside of its initializing function.

In order to also close the time window between zfcp_erp_setup_act()
memsetting the entire erp_action to zero and setting the parent pointers
again, drop the memset and instead explicitly initialize individually
all erp_action fields except for parent pointers. To be extra careful
not to introduce any other unintended side effect, even keep zeroing the
erp_action fields for list and timer. Also double-check with
WARN_ON_ONCE that erp_action parent pointers never change, so we get to
know when we would deviate from previous behavior.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery")
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ayufan pushed a commit that referenced this pull request Dec 17, 2017
commit a743bbe upstream.

The warning below says it all:

  BUG: using __this_cpu_read() in preemptible [00000000] code: swapper/0/1
  caller is __this_cpu_preempt_check
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-rc8 #4
  Call Trace:
   dump_stack
   check_preemption_disabled
   ? do_early_param
   __this_cpu_preempt_check
   arch_perfmon_init
   op_nmi_init
   ? alloc_pci_root_info
   oprofile_arch_init
   oprofile_init
   do_one_initcall
   ...

These accessors should not have been used in the first place: it is PPro so
no mixed silicon revisions and thus it can simply use boot_cpu_data.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Fix-creation-mandated-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Robert Richter <rric@kernel.org>
Cc: x86@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ayufan pushed a commit that referenced this pull request Dec 17, 2017
[ Upstream commit 6151b8b ]

ppp_release() tries to ensure that netdevices are unregistered before
decrementing the unit refcount and running ppp_destroy_interface().

This is all fine as long as the the device is unregistered by
ppp_release(): the unregister_netdevice() call, followed by
rtnl_unlock(), guarantee that the unregistration process completes
before rtnl_unlock() returns.

However, the device may be unregistered by other means (like
ppp_nl_dellink()). If this happens right before ppp_release() calling
rtnl_lock(), then ppp_release() has to wait for the concurrent
unregistration code to release the lock.
But rtnl_unlock() releases the lock before completing the device
unregistration process. This allows ppp_release() to proceed and
eventually call ppp_destroy_interface() before the unregistration
process completes. Calling free_netdev() on this partially unregistered
device will BUG():

 ------------[ cut here ]------------
 kernel BUG at net/core/dev.c:8141!
 invalid opcode: 0000 [#1] SMP

 CPU: 1 PID: 1557 Comm: pppd Not tainted 4.14.0-rc2+ #4
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc26 04/01/2014

 Call Trace:
  ppp_destroy_interface+0xd8/0xe0 [ppp_generic]
  ppp_disconnect_channel+0xda/0x110 [ppp_generic]
  ppp_unregister_channel+0x5e/0x110 [ppp_generic]
  pppox_unbind_sock+0x23/0x30 [pppox]
  pppoe_connect+0x130/0x440 [pppoe]
  SYSC_connect+0x98/0x110
  ? do_fcntl+0x2c0/0x5d0
  SyS_connect+0xe/0x10
  entry_SYSCALL_64_fastpath+0x1a/0xa5

 RIP: free_netdev+0x107/0x110 RSP: ffffc28a40573d88
 ---[ end trace ed294ff0cc40eeff ]---

We could set the ->needs_free_netdev flag on PPP devices and move the
ppp_destroy_interface() logic in the ->priv_destructor() callback. But
that'd be quite intrusive as we'd first need to unlink from the other
channels and units that depend on the device (the ones that used the
PPPIOCCONNECT and PPPIOCATTACH ioctls).

Instead, we can just let the netdevice hold a reference on its
ppp_file. This reference is dropped in ->priv_destructor(), at the very
end of the unregistration process, so that neither ppp_release() nor
ppp_disconnect_channel() can call ppp_destroy_interface() in the interim.

Reported-by: Beniamino Galvani <bgalvani@redhat.com>
Fixes: 8cb775b ("ppp: fix device unregistration upon netns deletion")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ayufan pushed a commit that referenced this pull request Feb 19, 2018
[ Upstream commit ec4fbd6 ]

Dmitry reported a lockdep splat [1] (false positive) that we can fix
by releasing the spinlock before calling icmp_send() from ip_expire()

This is a false positive because sending an ICMP message can not
possibly re-enter the IP frag engine.

[1]
[ INFO: possible circular locking dependency detected ]
4.10.0+ #29 Not tainted
-------------------------------------------------------
modprobe/12392 is trying to acquire lock:
 (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] spin_lock
include/linux/spinlock.h:299 [inline]
 (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] __netif_tx_lock
include/linux/netdevice.h:3486 [inline]
 (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>]
sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180

but task is already holding lock:
 (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] spin_lock
include/linux/spinlock.h:299 [inline]
 (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>]
ip_expire+0x51/0x6c0 net/ipv4/ip_fragment.c:201

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&(&q->lock)->rlock){+.-...}:
       validate_chain kernel/locking/lockdep.c:2267 [inline]
       __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340
       lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151
       spin_lock include/linux/spinlock.h:299 [inline]
       ip_defrag+0x3a2/0x4130 net/ipv4/ip_fragment.c:669
       ip_check_defrag+0x4e3/0x8b0 net/ipv4/ip_fragment.c:713
       packet_rcv_fanout+0x282/0x800 net/packet/af_packet.c:1459
       deliver_skb net/core/dev.c:1834 [inline]
       dev_queue_xmit_nit+0x294/0xa90 net/core/dev.c:1890
       xmit_one net/core/dev.c:2903 [inline]
       dev_hard_start_xmit+0x16b/0xab0 net/core/dev.c:2923
       sch_direct_xmit+0x31f/0x6d0 net/sched/sch_generic.c:182
       __dev_xmit_skb net/core/dev.c:3092 [inline]
       __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358
       dev_queue_xmit+0x17/0x20 net/core/dev.c:3423
       neigh_resolve_output+0x6b9/0xb10 net/core/neighbour.c:1308
       neigh_output include/net/neighbour.h:478 [inline]
       ip_finish_output2+0x8b8/0x15a0 net/ipv4/ip_output.c:228
       ip_do_fragment+0x1d93/0x2720 net/ipv4/ip_output.c:672
       ip_fragment.constprop.54+0x145/0x200 net/ipv4/ip_output.c:545
       ip_finish_output+0x82d/0xe10 net/ipv4/ip_output.c:314
       NF_HOOK_COND include/linux/netfilter.h:246 [inline]
       ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404
       dst_output include/net/dst.h:486 [inline]
       ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124
       ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492
       ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512
       raw_sendmsg+0x26de/0x3a00 net/ipv4/raw.c:655
       inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:761
       sock_sendmsg_nosec net/socket.c:633 [inline]
       sock_sendmsg+0xca/0x110 net/socket.c:643
       ___sys_sendmsg+0x4a3/0x9f0 net/socket.c:1985
       __sys_sendmmsg+0x25c/0x750 net/socket.c:2075
       SYSC_sendmmsg net/socket.c:2106 [inline]
       SyS_sendmmsg+0x35/0x60 net/socket.c:2101
       do_syscall_64+0x2e8/0x930 arch/x86/entry/common.c:281
       return_from_SYSCALL_64+0x0/0x7a

-> #0 (_xmit_ETHER#2){+.-...}:
       check_prev_add kernel/locking/lockdep.c:1830 [inline]
       check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940
       validate_chain kernel/locking/lockdep.c:2267 [inline]
       __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340
       lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151
       spin_lock include/linux/spinlock.h:299 [inline]
       __netif_tx_lock include/linux/netdevice.h:3486 [inline]
       sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180
       __dev_xmit_skb net/core/dev.c:3092 [inline]
       __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358
       dev_queue_xmit+0x17/0x20 net/core/dev.c:3423
       neigh_hh_output include/net/neighbour.h:468 [inline]
       neigh_output include/net/neighbour.h:476 [inline]
       ip_finish_output2+0xf6c/0x15a0 net/ipv4/ip_output.c:228
       ip_finish_output+0xa29/0xe10 net/ipv4/ip_output.c:316
       NF_HOOK_COND include/linux/netfilter.h:246 [inline]
       ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404
       dst_output include/net/dst.h:486 [inline]
       ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124
       ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492
       ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512
       icmp_push_reply+0x372/0x4d0 net/ipv4/icmp.c:394
       icmp_send+0x156c/0x1c80 net/ipv4/icmp.c:754
       ip_expire+0x40e/0x6c0 net/ipv4/ip_fragment.c:239
       call_timer_fn+0x241/0x820 kernel/time/timer.c:1268
       expire_timers kernel/time/timer.c:1307 [inline]
       __run_timers+0x960/0xcf0 kernel/time/timer.c:1601
       run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614
       __do_softirq+0x31f/0xbe7 kernel/softirq.c:284
       invoke_softirq kernel/softirq.c:364 [inline]
       irq_exit+0x1cc/0x200 kernel/softirq.c:405
       exiting_irq arch/x86/include/asm/apic.h:657 [inline]
       smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962
       apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:707
       __read_once_size include/linux/compiler.h:254 [inline]
       atomic_read arch/x86/include/asm/atomic.h:26 [inline]
       rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:350 [inline]
       __rcu_is_watching kernel/rcu/tree.c:1133 [inline]
       rcu_is_watching+0x83/0x110 kernel/rcu/tree.c:1147
       rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:293
       radix_tree_deref_slot include/linux/radix-tree.h:238 [inline]
       filemap_map_pages+0x6d4/0x1570 mm/filemap.c:2335
       do_fault_around mm/memory.c:3231 [inline]
       do_read_fault mm/memory.c:3265 [inline]
       do_fault+0xbd5/0x2080 mm/memory.c:3370
       handle_pte_fault mm/memory.c:3600 [inline]
       __handle_mm_fault+0x1062/0x2cb0 mm/memory.c:3714
       handle_mm_fault+0x1e2/0x480 mm/memory.c:3751
       __do_page_fault+0x4f6/0xb60 arch/x86/mm/fault.c:1397
       do_page_fault+0x54/0x70 arch/x86/mm/fault.c:1460
       page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1011

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&(&q->lock)->rlock);
                               lock(_xmit_ETHER#2);
                               lock(&(&q->lock)->rlock);
  lock(_xmit_ETHER#2);

 *** DEADLOCK ***

10 locks held by modprobe/12392:
 #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff81329758>]
__do_page_fault+0x2b8/0xb60 arch/x86/mm/fault.c:1336
 #1:  (rcu_read_lock){......}, at: [<ffffffff8188cab6>]
filemap_map_pages+0x1e6/0x1570 mm/filemap.c:2324
 #2:  (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>]
spin_lock include/linux/spinlock.h:299 [inline]
 #2:  (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>]
pte_alloc_one_map mm/memory.c:2944 [inline]
 #2:  (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>]
alloc_set_pte+0x13b8/0x1b90 mm/memory.c:3072
 #3:  (((&q->timer))){+.-...}, at: [<ffffffff81627e72>]
lockdep_copy_map include/linux/lockdep.h:175 [inline]
 #3:  (((&q->timer))){+.-...}, at: [<ffffffff81627e72>]
call_timer_fn+0x1c2/0x820 kernel/time/timer.c:1258
 #4:  (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] spin_lock
include/linux/spinlock.h:299 [inline]
 #4:  (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>]
ip_expire+0x51/0x6c0 net/ipv4/ip_fragment.c:201
 #5:  (rcu_read_lock){......}, at: [<ffffffff8389a633>]
ip_expire+0x1b3/0x6c0 net/ipv4/ip_fragment.c:216
 #6:  (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] spin_trylock
include/linux/spinlock.h:309 [inline]
 #6:  (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] icmp_xmit_lock
net/ipv4/icmp.c:219 [inline]
 #6:  (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>]
icmp_send+0x803/0x1c80 net/ipv4/icmp.c:681
 #7:  (rcu_read_lock_bh){......}, at: [<ffffffff838ab9a1>]
ip_finish_output2+0x2c1/0x15a0 net/ipv4/ip_output.c:198
 #8:  (rcu_read_lock_bh){......}, at: [<ffffffff836d1dee>]
__dev_queue_xmit+0x23e/0x1e60 net/core/dev.c:3324
 #9:  (dev->qdisc_running_key ?: &qdisc_running_key){+.....}, at:
[<ffffffff836d3a27>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3423

stack backtrace:
CPU: 0 PID: 12392 Comm: modprobe Not tainted 4.10.0+ #29
Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x2ee/0x3ef lib/dump_stack.c:52
 print_circular_bug+0x307/0x3b0 kernel/locking/lockdep.c:1204
 check_prev_add kernel/locking/lockdep.c:1830 [inline]
 check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940
 validate_chain kernel/locking/lockdep.c:2267 [inline]
 __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340
 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151
 spin_lock include/linux/spinlock.h:299 [inline]
 __netif_tx_lock include/linux/netdevice.h:3486 [inline]
 sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180
 __dev_xmit_skb net/core/dev.c:3092 [inline]
 __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3423
 neigh_hh_output include/net/neighbour.h:468 [inline]
 neigh_output include/net/neighbour.h:476 [inline]
 ip_finish_output2+0xf6c/0x15a0 net/ipv4/ip_output.c:228
 ip_finish_output+0xa29/0xe10 net/ipv4/ip_output.c:316
 NF_HOOK_COND include/linux/netfilter.h:246 [inline]
 ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404
 dst_output include/net/dst.h:486 [inline]
 ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124
 ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492
 ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512
 icmp_push_reply+0x372/0x4d0 net/ipv4/icmp.c:394
 icmp_send+0x156c/0x1c80 net/ipv4/icmp.c:754
 ip_expire+0x40e/0x6c0 net/ipv4/ip_fragment.c:239
 call_timer_fn+0x241/0x820 kernel/time/timer.c:1268
 expire_timers kernel/time/timer.c:1307 [inline]
 __run_timers+0x960/0xcf0 kernel/time/timer.c:1601
 run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614
 __do_softirq+0x31f/0xbe7 kernel/softirq.c:284
 invoke_softirq kernel/softirq.c:364 [inline]
 irq_exit+0x1cc/0x200 kernel/softirq.c:405
 exiting_irq arch/x86/include/asm/apic.h:657 [inline]
 smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962
 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:707
RIP: 0010:__read_once_size include/linux/compiler.h:254 [inline]
RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:26 [inline]
RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:350 [inline]
RIP: 0010:__rcu_is_watching kernel/rcu/tree.c:1133 [inline]
RIP: 0010:rcu_is_watching+0x83/0x110 kernel/rcu/tree.c:1147
RSP: 0000:ffff8801c391f120 EFLAGS: 00000a03 ORIG_RAX: ffffffffffffff10
RAX: dffffc0000000000 RBX: ffff8801c391f148 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 000055edd4374000 RDI: ffff8801dbe1ae0c
RBP: ffff8801c391f1a0 R08: 0000000000000002 R09: 0000000000000000
R10: dffffc0000000000 R11: 0000000000000002 R12: 1ffff10038723e25
R13: ffff8801dbe1ae00 R14: ffff8801c391f680 R15: dffffc0000000000
 </IRQ>
 rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:293
 radix_tree_deref_slot include/linux/radix-tree.h:238 [inline]
 filemap_map_pages+0x6d4/0x1570 mm/filemap.c:2335
 do_fault_around mm/memory.c:3231 [inline]
 do_read_fault mm/memory.c:3265 [inline]
 do_fault+0xbd5/0x2080 mm/memory.c:3370
 handle_pte_fault mm/memory.c:3600 [inline]
 __handle_mm_fault+0x1062/0x2cb0 mm/memory.c:3714
 handle_mm_fault+0x1e2/0x480 mm/memory.c:3751
 __do_page_fault+0x4f6/0xb60 arch/x86/mm/fault.c:1397
 do_page_fault+0x54/0x70 arch/x86/mm/fault.c:1460
 page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1011
RIP: 0033:0x7f83172f2786
RSP: 002b:00007fffe859ae80 EFLAGS: 00010293
RAX: 000055edd4373040 RBX: 00007f83175111c8 RCX: 000055edd4373238
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f8317510970
RBP: 00007fffe859afd0 R08: 0000000000000009 R09: 0000000000000000
R10: 0000000000000064 R11: 0000000000000000 R12: 000055edd4373040
R13: 0000000000000000 R14: 00007fffe859afe8 R15: 0000000000000000

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ayufan pushed a commit that referenced this pull request Feb 19, 2018
(cherry pick from commit 3d88d56)

Due to how the MONOTONIC_RAW accumulation logic was handled,
there is the potential for a 1ns discontinuity when we do
accumulations. This small discontinuity has for the most part
gone un-noticed, but since ARM64 enabled CLOCK_MONOTONIC_RAW
in their vDSO clock_gettime implementation, we've seen failures
with the inconsistency-check test in kselftest.

This patch addresses the issue by using the same sub-ns
accumulation handling that CLOCK_MONOTONIC uses, which avoids
the issue for in-kernel users.

Since the ARM64 vDSO implementation has its own clock_gettime
calculation logic, this patch reduces the frequency of errors,
but failures are still seen. The ARM64 vDSO will need to be
updated to include the sub-nanosecond xtime_nsec values in its
calculation for this issue to be completely fixed.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Tested-by: Daniel Mentz <danielmentz@google.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: "stable #4 . 8+" <stable@vger.kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Link: http://lkml.kernel.org/r/1496965462-20003-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Bug: 20045882
Bug: 63737556
Change-Id: I6c55dd7685f6bd212c6af9d09c527528e1dd5fa1
ayufan pushed a commit that referenced this pull request May 6, 2018
commit 1514839 upstream.

This patch fixes NULL pointer crash due to active timer running for abort
IOCB.

From crash dump analysis it was discoverd that get_next_timer_interrupt()
encountered a corrupted entry on the timer list.

 #9 [ffff95e1f6f0fd40] page_fault at ffffffff914fe8f8
    [exception RIP: get_next_timer_interrupt+440]
    RIP: ffffffff90ea3088  RSP: ffff95e1f6f0fdf0  RFLAGS: 00010013
    RAX: ffff95e1f6451028  RBX: 000218e2389e5f40  RCX: 00000001232ad600
    RDX: 0000000000000001  RSI: ffff95e1f6f0fdf0  RDI: 0000000001232ad6
    RBP: ffff95e1f6f0fe40   R8: ffff95e1f6451188   R9: 0000000000000001
    R10: 0000000000000016  R11: 0000000000000016  R12: 00000001232ad5f6
    R13: ffff95e1f6450000  R14: ffff95e1f6f0fdf8  R15: ffff95e1f6f0fe10
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018

Looking at the assembly of get_next_timer_interrupt(), address came
from %r8 (ffff95e1f6451188) which is pointing to list_head with single
entry at ffff95e5ff621178.

 0xffffffff90ea307a <get_next_timer_interrupt+426>:      mov    (%r8),%rdx
 0xffffffff90ea307d <get_next_timer_interrupt+429>:      cmp    %r8,%rdx
 0xffffffff90ea3080 <get_next_timer_interrupt+432>:      je     0xffffffff90ea30a7 <get_next_timer_interrupt+471>
 0xffffffff90ea3082 <get_next_timer_interrupt+434>:      nopw   0x0(%rax,%rax,1)
 0xffffffff90ea3088 <get_next_timer_interrupt+440>:      testb  $0x1,0x18(%rdx)

 crash> rd ffff95e1f6451188 10
 ffff95e1f6451188:  ffff95e5ff621178 ffff95e5ff621178   x.b.....x.b.....
 ffff95e1f6451198:  ffff95e1f6451198 ffff95e1f6451198   ..E.......E.....
 ffff95e1f64511a8:  ffff95e1f64511a8 ffff95e1f64511a8   ..E.......E.....
 ffff95e1f64511b8:  ffff95e77cf509a0 ffff95e77cf509a0   ...|.......|....
 ffff95e1f64511c8:  ffff95e1f64511c8 ffff95e1f64511c8   ..E.......E.....

 crash> rd ffff95e5ff621178 10
 ffff95e5ff621178:  0000000000000001 ffff95e15936aa00   ..........6Y....
 ffff95e5ff621188:  0000000000000000 00000000ffffffff   ................
 ffff95e5ff621198:  00000000000000a0 0000000000000010   ................
 ffff95e5ff6211a8:  ffff95e5ff621198 000000000000000c   ..b.............
 ffff95e5ff6211b8:  00000f5800000000 ffff95e751f8d720   ....X... ..Q....

 ffff95e5ff621178 belongs to freed mempool object at ffff95e5ff621080.

 CACHE            NAME                 OBJSIZE  ALLOCATED     TOTAL  SLABS  SSIZE
 ffff95dc7fd74d00 mnt_cache                384      19785     24948    594    16k
   SLAB              MEMORY            NODE  TOTAL  ALLOCATED  FREE
   ffffdc5dabfd8800  ffff95e5ff620000     1     42         29    13
   FREE / [ALLOCATED]
    ffff95e5ff621080  (cpu 6 cache)

Examining the contents of that memory reveals a pointer to a constant string
in the driver, "abort\0", which is set by qla24xx_async_abort_cmd().

 crash> rd ffffffffc059277c 20
 ffffffffc059277c:  6e490074726f6261 0074707572726574   abort.Interrupt.
 ffffffffc059278c:  00676e696c6c6f50 6920726576697244   Polling.Driver i
 ffffffffc059279c:  646f6d207325206e 6974736554000a65   n %s mode..Testi
 ffffffffc05927ac:  636976656420676e 786c252074612065   ng device at %lx
 ffffffffc05927bc:  6b63656843000a2e 646f727020676e69   ...Checking prod
 ffffffffc05927cc:  6f20444920746375 0a2e706968632066   uct ID of chip..
 ffffffffc05927dc:  5120646e756f4600 204130303232414c   .Found QLA2200A
 ffffffffc05927ec:  43000a2e70696843 20676e696b636568   Chip...Checking
 ffffffffc05927fc:  65786f626c69616d 6c636e69000a2e73   mailboxes...incl
 ffffffffc059280c:  756e696c2f656475 616d2d616d642f78   ude/linux/dma-ma

 crash> struct -ox srb_iocb
 struct srb_iocb {
           union {
               struct {...} logio;
               struct {...} els_logo;
               struct {...} tmf;
               struct {...} fxiocb;
               struct {...} abt;
               struct ct_arg ctarg;
               struct {...} mbx;
               struct {...} nack;
    [0x0 ] } u;
    [0xb8] struct timer_list timer;
    [0x108] void (*timeout)(void *);
 }
 SIZE: 0x110

 crash> ! bc
 ibase=16
 obase=10
 B8+40
 F8

The object is a srb_t, and at offset 0xf8 within that structure
(i.e. ffff95e5ff621080 + f8 -> ffff95e5ff621178) is a struct timer_list.

Cc: <stable@vger.kernel.org> #4.4+
Fixes: 4440e46 ("[SCSI] qla2xxx: Add IOCB Abort command asynchronous handling.")
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ayufan pushed a commit that referenced this pull request May 6, 2018
[ Upstream commit 72d5481 ]

It is unlikely request_threaded_irq will fail, but if it does for some
reason we should clear iommu->pr_irq in the error path. Also
intel_svm_finish_prq shouldn't try to clean up the page request
interrupt if pr_irq is 0. Without these, if request_threaded_irq were
to fail the following occurs:

fail with no fixes:

[    0.683147] ------------[ cut here ]------------
[    0.683148] NULL pointer, cannot free irq
[    0.683158] WARNING: CPU: 1 PID: 1 at kernel/irq/irqdomain.c:1632 irq_domain_free_irqs+0x126/0x140
[    0.683160] Modules linked in:
[    0.683163] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc2 #3
[    0.683165] Hardware name:                  /NUC7i3BNB, BIOS BNKBL357.86A.0036.2017.0105.1112 01/05/2017
[    0.683168] RIP: 0010:irq_domain_free_irqs+0x126/0x140
[    0.683169] RSP: 0000:ffffc90000037ce8 EFLAGS: 00010292
[    0.683171] RAX: 000000000000001d RBX: ffff880276283c00 RCX: ffffffff81c5e5e8
[    0.683172] RDX: 0000000000000001 RSI: 0000000000000096 RDI: 0000000000000246
[    0.683174] RBP: ffff880276283c00 R08: 0000000000000000 R09: 000000000000023c
[    0.683175] R10: 0000000000000007 R11: 0000000000000000 R12: 000000000000007a
[    0.683176] R13: 0000000000000001 R14: 0000000000000000 R15: 0000010010000000
[    0.683178] FS:  0000000000000000(0000) GS:ffff88027ec80000(0000) knlGS:0000000000000000
[    0.683180] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.683181] CR2: 0000000000000000 CR3: 0000000001c09001 CR4: 00000000003606e0
[    0.683182] Call Trace:
[    0.683189]  intel_svm_finish_prq+0x3c/0x60
[    0.683191]  free_dmar_iommu+0x1ac/0x1b0
[    0.683195]  init_dmars+0xaaa/0xaea
[    0.683200]  ? klist_next+0x19/0xc0
[    0.683203]  ? pci_do_find_bus+0x50/0x50
[    0.683205]  ? pci_get_dev_by_id+0x52/0x70
[    0.683208]  intel_iommu_init+0x498/0x5c7
[    0.683211]  pci_iommu_init+0x13/0x3c
[    0.683214]  ? e820__memblock_setup+0x61/0x61
[    0.683217]  do_one_initcall+0x4d/0x1a0
[    0.683220]  kernel_init_freeable+0x186/0x20e
[    0.683222]  ? set_debug_rodata+0x11/0x11
[    0.683225]  ? rest_init+0xb0/0xb0
[    0.683226]  kernel_init+0xa/0xff
[    0.683229]  ret_from_fork+0x1f/0x30
[    0.683259] Code: 89 ee 44 89 e7 e8 3b e8 ff ff 5b 5d 44 89 e7 44 89 ee 41 5c 41 5d 41 5e e9 a8 84 ff ff 48 c7 c7 a8 71 a7 81 31 c0 e8 6a d3 f9 ff <0f> ff 5b 5d 41 5c 41 5d 41 5
e c3 0f 1f 44 00 00 66 2e 0f 1f 84
[    0.683285] ---[ end trace f7650e42792627ca ]---

with iommu->pr_irq = 0, but no check in intel_svm_finish_prq:

[    0.669561] ------------[ cut here ]------------
[    0.669563] Trying to free already-free IRQ 0
[    0.669573] WARNING: CPU: 3 PID: 1 at kernel/irq/manage.c:1546 __free_irq+0xa4/0x2c0
[    0.669574] Modules linked in:
[    0.669577] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc2 #4
[    0.669579] Hardware name:                  /NUC7i3BNB, BIOS BNKBL357.86A.0036.2017.0105.1112 01/05/2017
[    0.669581] RIP: 0010:__free_irq+0xa4/0x2c0
[    0.669582] RSP: 0000:ffffc90000037cc0 EFLAGS: 00010082
[    0.669584] RAX: 0000000000000021 RBX: 0000000000000000 RCX: ffffffff81c5e5e8
[    0.669585] RDX: 0000000000000001 RSI: 0000000000000086 RDI: 0000000000000046
[    0.669587] RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000023c
[    0.669588] R10: 0000000000000007 R11: 0000000000000000 R12: ffff880276253960
[    0.669589] R13: ffff8802762538a4 R14: ffff880276253800 R15: ffff880276283600
[    0.669593] FS:  0000000000000000(0000) GS:ffff88027ed80000(0000) knlGS:0000000000000000
[    0.669594] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.669596] CR2: 0000000000000000 CR3: 0000000001c09001 CR4: 00000000003606e0
[    0.669602] Call Trace:
[    0.669616]  free_irq+0x30/0x60
[    0.669620]  intel_svm_finish_prq+0x34/0x60
[    0.669623]  free_dmar_iommu+0x1ac/0x1b0
[    0.669627]  init_dmars+0xaaa/0xaea
[    0.669631]  ? klist_next+0x19/0xc0
[    0.669634]  ? pci_do_find_bus+0x50/0x50
[    0.669637]  ? pci_get_dev_by_id+0x52/0x70
[    0.669639]  intel_iommu_init+0x498/0x5c7
[    0.669642]  pci_iommu_init+0x13/0x3c
[    0.669645]  ? e820__memblock_setup+0x61/0x61
[    0.669648]  do_one_initcall+0x4d/0x1a0
[    0.669651]  kernel_init_freeable+0x186/0x20e
[    0.669653]  ? set_debug_rodata+0x11/0x11
[    0.669656]  ? rest_init+0xb0/0xb0
[    0.669658]  kernel_init+0xa/0xff
[    0.669661]  ret_from_fork+0x1f/0x30
[    0.669662] Code: 7a 08 75 0e e9 c3 01 00 00 4c 39 7b 08 74 57 48 89 da 48 8b 5a 18 48 85 db 75 ee 89 ee 48 c7 c7 78 67 a7 81 31 c0 e8 4c 37 fa ff <0f> ff 48 8b 34 24 4c 89 ef e
8 0e 4c 68 00 49 8b 46 40 48 8b 80
[    0.669688] ---[ end trace 58a470248700f2fc ]---

Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ayufan pushed a commit that referenced this pull request May 6, 2018
According to the dwc2 programmer's guide v3.10a, in '2.1.3.2 Dedicated
FIFO Mode with No Thresholding', it suggested that:

Device RxFIFO =
- Scatter/Gather DMA mode:
(4 * number of control endpoints + 6) + ((largest USB packet used / 4) +
1 for status information) + (2 * number of OUT endpoints) + 1 for Global NAK

on rockchip platforms:
(4 * 1 + 6) + ((1024 / 4) + 1) + (2 * 6) + 1 = 280

- Slave or Buffer DMA mode:
(5 * number of control endpoints + 8) + ((largest USB packet used / 4) +
1 for status information) + (2 * number of OUT endpoints) + 1 for Global NAK

on rockchip platforms:
(5 * 1 + 8) + ((1024 / 4) + 1) + (2 * 6) + 1 = 283

Device IN Endpoint TxFIFO =
The TxFIFO must equal at least one MaxPacketSize (MPS).

In addition to RxFIFO and TxFIFOs, refer to dwc2 databook v3.10a,
'Figure 2-13 Device Mode FIFO Address Mapping and AHB FIFO Access Mapping
(Dedicated FIFO)', it required that when the device is operating in non
Scatter Gather Internal DMA mode, the last locations of the SPRAM are used
to store the DMAADDR values for each Endpoint (1 location per endpoint).

When the device is operating in Scatter Gather mode, then the last locations
of the SPRAM store the Base Descriptor address, Current Descriptor address,
Current Buffer address, and status quadlet information for each endpoint
direction (4 locations per Endpoint). If an Endpoint is bidirectional , then
4 locations will be used for IN, and another 4 for OUT).

Considering that the total FIFO size of dwc2 otg is 0x3cc (972),
and we must reserve (4 * 13) = 52 locations for all Endpoints.
So reconfig dwc2 device fifo size as follows:

Device RxFIFO = 280
Device IN Endpoint TxFIFO
- FIFO #0 = (64 / 4) = 16 (Assuming this is used for EP0)
- FIFO #1 = (1024/4) = 256 (Assuming this is used for Isochronous)
- FIFO #2 = (512/4) = 128
- FIFO #3 = (512/4) = 128
- FIFO #4 = (256/4) = 64
- FIFO #5 = (128/4) = 32
- FIFO #6 = (64/4) = 16

After reconfig the dwc2 device fifo size, test mtp write on rockchip
platform (PC -> rockchip platform) on rk312x/rk3326/px30/rk3288 evb,
when mask the 'vfs_write' in f_mtp.c, the writing data rate can be
increased from 16MBps ~ 20MBps to 30MBps ~ 36MBps on different kinds
of rockchip evbs.

Change-Id: Icdf8a5dd95f96d174233e4ffc765c9a982b9f0b6
Signed-off-by: William Wu <william.wu@rock-chips.com>
ayufan pushed a commit that referenced this pull request May 6, 2018
According to the dwc2 programmer's guide v3.10a, in '2.1.3.2 Dedicated
FIFO Mode with No Thresholding', it suggested that:

Device RxFIFO =
- Scatter/Gather DMA mode:
(4 * number of control endpoints + 6) + ((largest USB packet used / 4) +
1 for status information) + (2 * number of OUT endpoints) + 1 for Global NAK

on rockchip platforms:
(4 * 1 + 6) + ((1024 / 4) + 1) + (2 * 6) + 1 = 280

- Slave or Buffer DMA mode:
(5 * number of control endpoints + 8) + ((largest USB packet used / 4) +
1 for status information) + (2 * number of OUT endpoints) + 1 for Global NAK

on rockchip platforms:
(5 * 1 + 8) + ((1024 / 4) + 1) + (2 * 6) + 1 = 283

Device IN Endpoint TxFIFO =
The TxFIFO must equal at least one MaxPacketSize (MPS).

In addition to RxFIFO and TxFIFOs, refer to dwc2 databook v3.10a,
'Figure 2-13 Device Mode FIFO Address Mapping and AHB FIFO Access Mapping
(Dedicated FIFO)', it required that when the device is operating in non
Scatter Gather Internal DMA mode, the last locations of the SPRAM are used
to store the DMAADDR values for each Endpoint (1 location per endpoint).

When the device is operating in Scatter Gather mode, then the last locations
of the SPRAM store the Base Descriptor address, Current Descriptor address,
Current Buffer address, and status quadlet information for each endpoint
direction (4 locations per Endpoint). If an Endpoint is bidirectional , then
4 locations will be used for IN, and another 4 for OUT).

Considering that the total FIFO size of dwc2 otg is 0x3cc (972),
and we must reserve (4 * 13) = 52 locations for all Endpoints.
So reconfig dwc2 device fifo size as follows:

Device RxFIFO = 280
Device IN Endpoint TxFIFO
- FIFO #0 = (64 / 4) = 16 (Assuming this is used for EP0)
- FIFO #1 = (1024/4) = 256 (Assuming this is used for Isochronous)
- FIFO #2 = (512/4) = 128
- FIFO #3 = (512/4) = 128
- FIFO #4 = (256/4) = 64
- FIFO #5 = (128/4) = 32
- FIFO #6 = (64/4) = 16

After reconfig the dwc2 device fifo size, test mtp write on rockchip
platform (PC -> rockchip platform) on rk312x/rk3326/px30/rk3288 evb,
when mask the 'vfs_write' in f_mtp.c, the writing data rate can be
increased from 16MBps ~ 20MBps to 30MBps ~ 36MBps on different kinds
of rockchip evbs.

Change-Id: I52c64a279523c811f706e69e427b0a6e8c45683b
Signed-off-by: William Wu <william.wu@rock-chips.com>
ayufan pushed a commit that referenced this pull request Jun 14, 2018
[ Upstream commit d754941 ]

If, for any reason, userland shuts down iscsi transport interfaces
before proper logouts - like when logging in to LUNs manually, without
logging out on server shutdown, or when automated scripts can't
umount/logout from logged LUNs - kernel will hang forever on its
sd_sync_cache() logic, after issuing the SYNCHRONIZE_CACHE cmd to all
still existent paths.

PID: 1 TASK: ffff8801a69b8000 CPU: 1 COMMAND: "systemd-shutdow"
 #0 [ffff8801a69c3a30] __schedule at ffffffff8183e9ee
 #1 [ffff8801a69c3a80] schedule at ffffffff8183f0d5
 #2 [ffff8801a69c3a98] schedule_timeout at ffffffff81842199
 #3 [ffff8801a69c3b40] io_schedule_timeout at ffffffff8183e604
 #4 [ffff8801a69c3b70] wait_for_completion_io_timeout at ffffffff8183fc6c
 #5 [ffff8801a69c3bd0] blk_execute_rq at ffffffff813cfe10
 #6 [ffff8801a69c3c88] scsi_execute at ffffffff815c3fc7
 #7 [ffff8801a69c3cc8] scsi_execute_req_flags at ffffffff815c60fe
 #8 [ffff8801a69c3d30] sd_sync_cache at ffffffff815d37d7
 #9 [ffff8801a69c3da8] sd_shutdown at ffffffff815d3c3c

This happens because iscsi_eh_cmd_timed_out(), the transport layer
timeout helper, would tell the queue timeout function (scsi_times_out)
to reset the request timer over and over, until the session state is
back to logged in state. Unfortunately, during server shutdown, this
might never happen again.

Other option would be "not to handle" the issue in the transport
layer. That would trigger the error handler logic, which would also need
the session state to be logged in again.

Best option, for such case, is to tell upper layers that the command was
handled during the transport layer error handler helper, marking it as
DID_NO_CONNECT, which will allow completion and inform about the
problem.

After the session was marked as ISCSI_STATE_FAILED, due to the first
timeout during the server shutdown phase, all subsequent cmds will fail
to be queued, allowing upper logic to fail faster.

Signed-off-by: Rafael David Tinoco <rafael.tinoco@canonical.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ayufan pushed a commit that referenced this pull request Aug 9, 2018
commit 3d88d56 upstream.

Due to how the MONOTONIC_RAW accumulation logic was handled,
there is the potential for a 1ns discontinuity when we do
accumulations. This small discontinuity has for the most part
gone un-noticed, but since ARM64 enabled CLOCK_MONOTONIC_RAW
in their vDSO clock_gettime implementation, we've seen failures
with the inconsistency-check test in kselftest.

This patch addresses the issue by using the same sub-ns
accumulation handling that CLOCK_MONOTONIC uses, which avoids
the issue for in-kernel users.

Since the ARM64 vDSO implementation has its own clock_gettime
calculation logic, this patch reduces the frequency of errors,
but failures are still seen. The ARM64 vDSO will need to be
updated to include the sub-nanosecond xtime_nsec values in its
calculation for this issue to be completely fixed.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Tested-by: Daniel Mentz <danielmentz@google.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: "stable #4 . 8+" <stable@vger.kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Link: http://lkml.kernel.org/r/1496965462-20003-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[fabrizio: cherry-pick to 4.4. Kept cycle_t type for function
logarithmic_accumulation local variable "interval". Dropped
casting of "interval" variable]
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ayufan pushed a commit that referenced this pull request Aug 9, 2018
[ Upstream commit 2c0aa08 ]

Scenario:
1. Port down and do fail over
2. Ap do rds_bind syscall

PID: 47039  TASK: ffff89887e2fe640  CPU: 47  COMMAND: "kworker/u:6"
 #0 [ffff898e35f159f0] machine_kexec at ffffffff8103abf9
 #1 [ffff898e35f15a60] crash_kexec at ffffffff810b96e3
 #2 [ffff898e35f15b30] oops_end at ffffffff8150f518
 #3 [ffff898e35f15b60] no_context at ffffffff8104854c
 #4 [ffff898e35f15ba0] __bad_area_nosemaphore at ffffffff81048675
 #5 [ffff898e35f15bf0] bad_area_nosemaphore at ffffffff810487d3
 #6 [ffff898e35f15c00] do_page_fault at ffffffff815120b8
 #7 [ffff898e35f15d10] page_fault at ffffffff8150ea95
    [exception RIP: unknown or invalid address]
    RIP: 0000000000000000  RSP: ffff898e35f15dc8  RFLAGS: 00010282
    RAX: 00000000fffffffe  RBX: ffff889b77f6fc00  RCX:ffffffff81c99d88
    RDX: 0000000000000000  RSI: ffff896019ee08e8  RDI:ffff889b77f6fc00
    RBP: ffff898e35f15df0   R8: ffff896019ee08c8  R9:0000000000000000
    R10: 0000000000000400  R11: 0000000000000000  R12:ffff896019ee08c0
    R13: ffff889b77f6fe68  R14: ffffffff81c99d80  R15: ffffffffa022a1e0
    ORIG_RAX: ffffffffffffffff  CS: 0010 SS: 0018
 #8 [ffff898e35f15dc8] cma_ndev_work_handler at ffffffffa022a228 [rdma_cm]
 #9 [ffff898e35f15df8] process_one_work at ffffffff8108a7c6
 #10 [ffff898e35f15e58] worker_thread at ffffffff8108bda0
 #11 [ffff898e35f15ee8] kthread at ffffffff81090fe6

PID: 45659  TASK: ffff880d313d2500  CPU: 31  COMMAND: "oracle_45659_ap"
 #0 [ffff881024ccfc98] __schedule at ffffffff8150bac4
 #1 [ffff881024ccfd40] schedule at ffffffff8150c2cf
 #2 [ffff881024ccfd50] __mutex_lock_slowpath at ffffffff8150cee7
 #3 [ffff881024ccfdc0] mutex_lock at ffffffff8150cdeb
 #4 [ffff881024ccfde0] rdma_destroy_id at ffffffffa022a027 [rdma_cm]
 #5 [ffff881024ccfe10] rds_ib_laddr_check at ffffffffa0357857 [rds_rdma]
 #6 [ffff881024ccfe50] rds_trans_get_preferred at ffffffffa0324c2a [rds]
 #7 [ffff881024ccfe80] rds_bind at ffffffffa031d690 [rds]
 #8 [ffff881024ccfeb0] sys_bind at ffffffff8142a670

PID: 45659                          PID: 47039
rds_ib_laddr_check
  /* create id_priv with a null event_handler */
  rdma_create_id
  rdma_bind_addr
    cma_acquire_dev
      /* add id_priv to cma_dev->id_list */
      cma_attach_to_dev
                                    cma_ndev_work_handler
                                      /* event_hanlder is null */
                                      id_priv->id.event_handler

Signed-off-by: Guanglei Li <guanglei.li@oracle.com>
Signed-off-by: Honglei Wang <honglei.wang@oracle.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Yanjun Zhu <yanjun.zhu@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ayufan pushed a commit that referenced this pull request Aug 9, 2018
[ Upstream commit f61e643 ]

As of commit 205e1b7 ("dma-mapping: warn when there is no
coherent_dma_mask") the Freescale FEC driver is issuing the following
warning on driver initialization on ColdFire systems:

WARNING: CPU: 0 PID: 1 at ./include/linux/dma-mapping.h:516 0x40159e20
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 4.16.0-rc7-dirty #4
Stack from 41833dd8:
        41833dd8 40259c53 40025534 40279e26 00000003 00000000 4004e514 41827000
        400255de 40244e42 00000204 40159e20 00000009 00000000 00000000 4024531d
        40159e20 40244e42 00000204 00000000 00000000 00000000 00000007 00000000
        00000000 40279e26 4028d040 40226576 4003ae88 40279e26 418273f6 41833ef8
        7fffffff 418273f2 41867028 4003c9a2 4180ac6c 00000004 41833f8c 4013e71c
        40279e1c 40279e26 40226c16 4013ced2 40279e26 40279e58 4028d040 00000000
Call Trace:
        [<40025534>] 0x40025534
 [<4004e514>] 0x4004e514
 [<400255de>] 0x400255de
 [<40159e20>] 0x40159e20
 [<40159e20>] 0x40159e20

It is not fatal, the driver and the system continue to function normally.

As per the warning the coherent_dma_mask is not set on this device.
There is nothing special about the DMA memory coherency on this hardware
so we can just set the mask to 32bits in the platform data for the FEC
ethernet devices.

Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ayufan pushed a commit that referenced this pull request Aug 9, 2018
[ Upstream commit 2bbea6e ]

when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 #5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 #6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 #7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 #8 [ffff880078447da8] mount_bdev at ffffffff81202570
 #9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
#10 [ffff880078447e28] mount_fs at ffffffff81202d09
#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
#12 [ffff880078447ea8] do_mount at ffffffff81220fee
#13 [ffff880078447f28] sys_mount at ffffffff812218d6
#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 #1 [ffff880078417900] schedule at ffffffff8168dc59
 #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 #4 [ffff8800784179d0] down_read at ffffffff8168cde0
 #5 [ffff8800784179e8] get_super at ffffffff81201cc7
 #6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 #7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 #8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 #9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
#16 [ffff880078417d00] do_last at ffffffff8120d53d
#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
#20 [ffff880078417f70] sys_open at ffffffff811fde4e
#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ayufan pushed a commit that referenced this pull request Sep 29, 2018
[ Upstream commit 2c0aa08 ]

Scenario:
1. Port down and do fail over
2. Ap do rds_bind syscall

PID: 47039  TASK: ffff89887e2fe640  CPU: 47  COMMAND: "kworker/u:6"
 #0 [ffff898e35f159f0] machine_kexec at ffffffff8103abf9
 #1 [ffff898e35f15a60] crash_kexec at ffffffff810b96e3
 #2 [ffff898e35f15b30] oops_end at ffffffff8150f518
 #3 [ffff898e35f15b60] no_context at ffffffff8104854c
 #4 [ffff898e35f15ba0] __bad_area_nosemaphore at ffffffff81048675
 #5 [ffff898e35f15bf0] bad_area_nosemaphore at ffffffff810487d3
 #6 [ffff898e35f15c00] do_page_fault at ffffffff815120b8
 #7 [ffff898e35f15d10] page_fault at ffffffff8150ea95
    [exception RIP: unknown or invalid address]
    RIP: 0000000000000000  RSP: ffff898e35f15dc8  RFLAGS: 00010282
    RAX: 00000000fffffffe  RBX: ffff889b77f6fc00  RCX:ffffffff81c99d88
    RDX: 0000000000000000  RSI: ffff896019ee08e8  RDI:ffff889b77f6fc00
    RBP: ffff898e35f15df0   R8: ffff896019ee08c8  R9:0000000000000000
    R10: 0000000000000400  R11: 0000000000000000  R12:ffff896019ee08c0
    R13: ffff889b77f6fe68  R14: ffffffff81c99d80  R15: ffffffffa022a1e0
    ORIG_RAX: ffffffffffffffff  CS: 0010 SS: 0018
 #8 [ffff898e35f15dc8] cma_ndev_work_handler at ffffffffa022a228 [rdma_cm]
 #9 [ffff898e35f15df8] process_one_work at ffffffff8108a7c6
 #10 [ffff898e35f15e58] worker_thread at ffffffff8108bda0
 #11 [ffff898e35f15ee8] kthread at ffffffff81090fe6

PID: 45659  TASK: ffff880d313d2500  CPU: 31  COMMAND: "oracle_45659_ap"
 #0 [ffff881024ccfc98] __schedule at ffffffff8150bac4
 #1 [ffff881024ccfd40] schedule at ffffffff8150c2cf
 #2 [ffff881024ccfd50] __mutex_lock_slowpath at ffffffff8150cee7
 #3 [ffff881024ccfdc0] mutex_lock at ffffffff8150cdeb
 #4 [ffff881024ccfde0] rdma_destroy_id at ffffffffa022a027 [rdma_cm]
 #5 [ffff881024ccfe10] rds_ib_laddr_check at ffffffffa0357857 [rds_rdma]
 #6 [ffff881024ccfe50] rds_trans_get_preferred at ffffffffa0324c2a [rds]
 #7 [ffff881024ccfe80] rds_bind at ffffffffa031d690 [rds]
 #8 [ffff881024ccfeb0] sys_bind at ffffffff8142a670

PID: 45659                          PID: 47039
rds_ib_laddr_check
  /* create id_priv with a null event_handler */
  rdma_create_id
  rdma_bind_addr
    cma_acquire_dev
      /* add id_priv to cma_dev->id_list */
      cma_attach_to_dev
                                    cma_ndev_work_handler
                                      /* event_hanlder is null */
                                      id_priv->id.event_handler

Signed-off-by: Guanglei Li <guanglei.li@oracle.com>
Signed-off-by: Honglei Wang <honglei.wang@oracle.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Yanjun Zhu <yanjun.zhu@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ayufan pushed a commit that referenced this pull request Sep 29, 2018
[ Upstream commit f61e643 ]

As of commit 205e1b7 ("dma-mapping: warn when there is no
coherent_dma_mask") the Freescale FEC driver is issuing the following
warning on driver initialization on ColdFire systems:

WARNING: CPU: 0 PID: 1 at ./include/linux/dma-mapping.h:516 0x40159e20
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 4.16.0-rc7-dirty #4
Stack from 41833dd8:
        41833dd8 40259c53 40025534 40279e26 00000003 00000000 4004e514 41827000
        400255de 40244e42 00000204 40159e20 00000009 00000000 00000000 4024531d
        40159e20 40244e42 00000204 00000000 00000000 00000000 00000007 00000000
        00000000 40279e26 4028d040 40226576 4003ae88 40279e26 418273f6 41833ef8
        7fffffff 418273f2 41867028 4003c9a2 4180ac6c 00000004 41833f8c 4013e71c
        40279e1c 40279e26 40226c16 4013ced2 40279e26 40279e58 4028d040 00000000
Call Trace:
        [<40025534>] 0x40025534
 [<4004e514>] 0x4004e514
 [<400255de>] 0x400255de
 [<40159e20>] 0x40159e20
 [<40159e20>] 0x40159e20

It is not fatal, the driver and the system continue to function normally.

As per the warning the coherent_dma_mask is not set on this device.
There is nothing special about the DMA memory coherency on this hardware
so we can just set the mask to 32bits in the platform data for the FEC
ethernet devices.

Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ayufan pushed a commit that referenced this pull request Sep 29, 2018
[ Upstream commit 2bbea6e ]

when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 #5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 #6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 #7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 #8 [ffff880078447da8] mount_bdev at ffffffff81202570
 #9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
#10 [ffff880078447e28] mount_fs at ffffffff81202d09
#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
#12 [ffff880078447ea8] do_mount at ffffffff81220fee
#13 [ffff880078447f28] sys_mount at ffffffff812218d6
#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 #1 [ffff880078417900] schedule at ffffffff8168dc59
 #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 #4 [ffff8800784179d0] down_read at ffffffff8168cde0
 #5 [ffff8800784179e8] get_super at ffffffff81201cc7
 #6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 #7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 #8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 #9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
#16 [ffff880078417d00] do_last at ffffffff8120d53d
#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
#20 [ffff880078417f70] sys_open at ffffffff811fde4e
#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ayufan pushed a commit that referenced this pull request Sep 29, 2018
commit 89da619 upstream.

Kernel panic when with high memory pressure, calltrace looks like,

PID: 21439 TASK: ffff881be3afedd0 CPU: 16 COMMAND: "java"
 #0 [ffff881ec7ed7630] machine_kexec at ffffffff81059beb
 #1 [ffff881ec7ed7690] __crash_kexec at ffffffff81105942
 #2 [ffff881ec7ed7760] crash_kexec at ffffffff81105a30
 #3 [ffff881ec7ed7778] oops_end at ffffffff816902c8
 #4 [ffff881ec7ed77a0] no_context at ffffffff8167ff46
 #5 [ffff881ec7ed77f0] __bad_area_nosemaphore at ffffffff8167ffdc
 #6 [ffff881ec7ed7838] __node_set at ffffffff81680300
 #7 [ffff881ec7ed7860] __do_page_fault at ffffffff8169320f
 #8 [ffff881ec7ed78c0] do_page_fault at ffffffff816932b5
 #9 [ffff881ec7ed78f0] page_fault at ffffffff8168f4c8
    [exception RIP: _raw_spin_lock_irqsave+47]
    RIP: ffffffff8168edef RSP: ffff881ec7ed79a8 RFLAGS: 00010046
    RAX: 0000000000000246 RBX: ffffea0019740d00 RCX: ffff881ec7ed7fd8
    RDX: 0000000000020000 RSI: 0000000000000016 RDI: 0000000000000008
    RBP: ffff881ec7ed79a8 R8: 0000000000000246 R9: 000000000001a098
    R10: ffff88107ffda000 R11: 0000000000000000 R12: 0000000000000000
    R13: 0000000000000008 R14: ffff881ec7ed7a80 R15: ffff881be3afedd0
    ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018

It happens in the pagefault and results in double pagefault
during compacting pages when memory allocation fails.

Analysed the vmcore, the page leads to second pagefault is corrupted
with _mapcount=-256, but private=0.

It's caused by the race between migration and ballooning, and lock
missing in virtballoon_migratepage() of virtio_balloon driver.
This patch fix the bug.

Fixes: e225042 ("virtio_balloon: introduce migration primitives to balloon pages")
Cc: stable@vger.kernel.org
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Huang Chong <huang.chong@zte.com.cn>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Apr 16, 2020
commit 143f6e7 upstream.

7471fb7 ("md/raid6: Fix anomily when recovering a single device in
RAID6.") avoids rereading P when it can be computed from other members.
However, this misses the chance to re-write the right data to P. This
patch sets R5_ReadError if the re-read fails.

Also, when re-read is skipped, we also missed the chance to reset
rdev->read_errors to 0. It can fail the disk when there are many read
errors on P member disk (other disks don't have read error)

V2: upper layer read request don't read parity/Q data. So there is no
need to consider such situation.

This is Reported-by: kbuild test robot <lkp@intel.com>

Fixes: 7471fb7 ("md/raid6: Fix anomily when recovering a single device in RAID6.")
Cc: <stable@vger.kernel.org> #4.4+
Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Apr 16, 2020
During backport f7eea63 ("KVM: nVMX: handle page fault in vmread"),
there was a mistake the exception reference should be passed to function
kvm_write_guest_virt_system, instead of NULL, other wise, we will get
NULL pointer deref, eg

kvm-unit-test triggered a NULL pointer deref below:
[  948.518437] kvm [24114]: vcpu0, guest rIP: 0x407ef9 kvm_set_msr_common: MSR_IA32_DEBUGCTLMSR 0x3, nop
[  949.106464] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
[  949.106707] PGD 0 P4D 0
[  949.106872] Oops: 0002 [#1] SMP
[  949.107038] CPU: 2 PID: 24126 Comm: qemu-2.7 Not tainted 4.19.77-pserver #4.19.77-1+feature+daily+update+20191005.1625+a4168bb~deb9
[  949.107283] Hardware name: Dell Inc. Precision Tower 3620/09WH54, BIOS 2.7.3 01/31/2018
[  949.107549] RIP: 0010:kvm_write_guest_virt_system+0x12/0x40 [kvm]
[  949.107719] Code: c0 5d 41 5c 41 5d 41 5e 83 f8 03 41 0f 94 c0 41 c1 e0 02 e9 b0 ed ff ff 0f 1f 44 00 00 48 89 f0 c6 87 59 56 00 00 01 48 89 d6 <49> c7 00 00 00 00 00 89 ca 49 c7 40 08 00 00 00 00 49 c7 40 10 00
[  949.108044] RSP: 0018:ffffb31b0a953cb0 EFLAGS: 00010202
[  949.108216] RAX: 000000000046b4d8 RBX: ffff9e9f415b0000 RCX: 0000000000000008
[  949.108389] RDX: ffffb31b0a953cc0 RSI: ffffb31b0a953cc0 RDI: ffff9e9f415b0000
[  949.108562] RBP: 00000000d2e14928 R08: 0000000000000000 R09: 0000000000000000
[  949.108733] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffffffffc8
[  949.108907] R13: 0000000000000002 R14: ffff9e9f4f26f2e8 R15: 0000000000000000
[  949.109079] FS:  00007eff8694c700(0000) GS:ffff9e9f51a80000(0000) knlGS:0000000031415928
[  949.109318] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  949.109495] CR2: 0000000000000000 CR3: 00000003be53b002 CR4: 00000000003626e0
[  949.109671] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  949.109845] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  949.110017] Call Trace:
[  949.110186]  handle_vmread+0x22b/0x2f0 [kvm_intel]
[  949.110356]  ? vmexit_fill_RSB+0xc/0x30 [kvm_intel]
[  949.110549]  kvm_arch_vcpu_ioctl_run+0xa98/0x1b30 [kvm]
[  949.110725]  ? kvm_vcpu_ioctl+0x388/0x5d0 [kvm]
[  949.110901]  kvm_vcpu_ioctl+0x388/0x5d0 [kvm]
[  949.111072]  do_vfs_ioctl+0xa2/0x620

Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
scpcom referenced this pull request in scpcom/linux Apr 16, 2020
[ Upstream commit 443f2d5 ]

Observe a segmentation fault when 'perf stat' is asked to repeat forever
with the interval option.

Without fix:

  # perf stat -r 0 -I 5000 -e cycles -a sleep 10
  #           time             counts unit events
       5.000211692  3,13,89,82,34,157      cycles
      10.000380119  1,53,98,52,22,294      cycles
      10.040467280       17,16,79,265      cycles
  Segmentation fault

This problem was only observed when we use forever option aka -r 0 and
works with limited repeats. Calling print_counter with ts being set to
NULL, is not a correct option when interval is set. Hence avoid
print_counter(NULL,..)  if interval is set.

With fix:

  # perf stat -r 0 -I 5000 -e cycles -a sleep 10
   #           time             counts unit events
       5.019866622  3,15,14,43,08,697      cycles
      10.039865756  3,15,16,31,95,261      cycles
      10.059950628     1,26,05,47,158      cycles
       5.009902655  3,14,52,62,33,932      cycles
      10.019880228  3,14,52,22,89,154      cycles
      10.030543876       66,90,18,333      cycles
       5.009848281  3,14,51,98,25,437      cycles
      10.029854402  3,15,14,93,04,918      cycles
       5.009834177  3,14,51,95,92,316      cycles

Committer notes:

Did the 'git bisect' to find the cset introducing the problem to add the
Fixes tag below, and at that time the problem reproduced as:

  (gdb) run stat -r0 -I500 sleep 1
  <SNIP>
  Program received signal SIGSEGV, Segmentation fault.
  print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866
  866		sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, csv_sep);
  (gdb) bt
  #0  print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866
  #1  0x000000000041860a in print_counters (ts=ts@entry=0x0, argc=argc@entry=2, argv=argv@entry=0x7fffffffd640) at builtin-stat.c:938
  #2  0x0000000000419a7f in cmd_stat (argc=2, argv=0x7fffffffd640, prefix=<optimized out>) at builtin-stat.c:1411
  #3  0x000000000045c65a in run_builtin (p=p@entry=0x6291b8 <commands+216>, argc=argc@entry=5, argv=argv@entry=0x7fffffffd640) at perf.c:370
  #4  0x000000000045c893 in handle_internal_command (argc=5, argv=0x7fffffffd640) at perf.c:429
  #5  0x000000000045c8f1 in run_argv (argcp=argcp@entry=0x7fffffffd4ac, argv=argv@entry=0x7fffffffd4a0) at perf.c:473
  ayufan-rock64#6  0x000000000045cac9 in main (argc=<optimized out>, argv=<optimized out>) at perf.c:588
  (gdb)

Mostly the same as just before this patch:

  Program received signal SIGSEGV, Segmentation fault.
  0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964
  964		sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, config->csv_sep);
  (gdb) bt
  #0  0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964
  #1  0x0000000000588047 in perf_evlist__print_counters (evlist=0xbc9b90, config=0xa1f2a0 <stat_config>, _target=0xa1f0c0 <target>, ts=0x0, argc=2, argv=0x7fffffffd670)
      at util/stat-display.c:1172
  #2  0x000000000045390f in print_counters (ts=0x0, argc=2, argv=0x7fffffffd670) at builtin-stat.c:656
  #3  0x0000000000456bb5 in cmd_stat (argc=2, argv=0x7fffffffd670) at builtin-stat.c:1960
  #4  0x00000000004dd2e0 in run_builtin (p=0xa30e00 <commands+288>, argc=5, argv=0x7fffffffd670) at perf.c:310
  #5  0x00000000004dd54d in handle_internal_command (argc=5, argv=0x7fffffffd670) at perf.c:362
  ayufan-rock64#6  0x00000000004dd694 in run_argv (argcp=0x7fffffffd4cc, argv=0x7fffffffd4c0) at perf.c:406
  ayufan-rock64#7  0x00000000004dda11 in main (argc=5, argv=0x7fffffffd670) at perf.c:531
  (gdb)

Fixes: d4f63a4 ("perf stat: Introduce print_counters function")
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v4.2+
Link: http://lore.kernel.org/lkml/20190904094738.9558-3-srikar@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Apr 16, 2020
commit ab42b48 upstream.

The "auto-attach" handler function `gsc_hpdi_auto_attach()` calls
`dma_alloc_coherent()` in a loop to allocate some DMA data buffers, and
also calls it to allocate a buffer for a DMA descriptor chain.  However,
it does not check the return value of any of these calls.  Change
`gsc_hpdi_auto_attach()` to return `-ENOMEM` if any of these
`dma_alloc_coherent()` calls fail.  This will result in the comedi core
calling the "detach" handler `gsc_hpdi_detach()` as part of the
clean-up, which will call `gsc_hpdi_free_dma()` to free any allocated
DMA coherent memory buffers.

Cc: <stable@vger.kernel.org> #4.6+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20191216110823.216237-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Apr 16, 2020
commit 5c9934b upstream.

We got another syzbot report [1] that tells us we must use
write_lock_irq()/write_unlock_irq() to avoid possible deadlock.

[1]

WARNING: inconsistent lock state
5.5.0-rc1-syzkaller #0 Not tainted
--------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-R} usage.
syz-executor826/9605 [HC1[1]:SC0[0]:HE0:SE1] takes:
ffffffff8a128718 (disc_data_lock){+-..}, at: sp_get.isra.0+0x1d/0xf0 drivers/net/ppp/ppp_synctty.c:138
{HARDIRQ-ON-W} state was registered at:
  lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485
  __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline]
  _raw_write_lock_bh+0x33/0x50 kernel/locking/spinlock.c:319
  sixpack_close+0x1d/0x250 drivers/net/hamradio/6pack.c:657
  tty_ldisc_close.isra.0+0x119/0x1a0 drivers/tty/tty_ldisc.c:489
  tty_set_ldisc+0x230/0x6b0 drivers/tty/tty_ldisc.c:585
  tiocsetd drivers/tty/tty_io.c:2337 [inline]
  tty_ioctl+0xe8d/0x14f0 drivers/tty/tty_io.c:2597
  vfs_ioctl fs/ioctl.c:47 [inline]
  file_ioctl fs/ioctl.c:545 [inline]
  do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732
  ksys_ioctl+0xab/0xd0 fs/ioctl.c:749
  __do_sys_ioctl fs/ioctl.c:756 [inline]
  __se_sys_ioctl fs/ioctl.c:754 [inline]
  __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754
  do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
irq event stamp: 3946
hardirqs last  enabled at (3945): [<ffffffff87c86e43>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline]
hardirqs last  enabled at (3945): [<ffffffff87c86e43>] _raw_spin_unlock_irq+0x23/0x80 kernel/locking/spinlock.c:199
hardirqs last disabled at (3946): [<ffffffff8100675f>] trace_hardirqs_off_thunk+0x1a/0x1c arch/x86/entry/thunk_64.S:42
softirqs last  enabled at (2658): [<ffffffff86a8b4df>] spin_unlock_bh include/linux/spinlock.h:383 [inline]
softirqs last  enabled at (2658): [<ffffffff86a8b4df>] clusterip_netdev_event+0x46f/0x670 net/ipv4/netfilter/ipt_CLUSTERIP.c:222
softirqs last disabled at (2656): [<ffffffff86a8b22b>] spin_lock_bh include/linux/spinlock.h:343 [inline]
softirqs last disabled at (2656): [<ffffffff86a8b22b>] clusterip_netdev_event+0x1bb/0x670 net/ipv4/netfilter/ipt_CLUSTERIP.c:196

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(disc_data_lock);
  <Interrupt>
    lock(disc_data_lock);

 *** DEADLOCK ***

5 locks held by syz-executor826/9605:
 #0: ffff8880a905e198 (&tty->legacy_mutex){+.+.}, at: tty_lock+0xc7/0x130 drivers/tty/tty_mutex.c:19
 #1: ffffffff899a56c0 (rcu_read_lock){....}, at: mutex_spin_on_owner+0x0/0x330 kernel/locking/mutex.c:413
 #2: ffff8880a496a2b0 (&(&i->lock)->rlock){-.-.}, at: spin_lock include/linux/spinlock.h:338 [inline]
 #2: ffff8880a496a2b0 (&(&i->lock)->rlock){-.-.}, at: serial8250_interrupt+0x2d/0x1a0 drivers/tty/serial/8250/8250_core.c:116
 #3: ffffffff8c104048 (&port_lock_key){-.-.}, at: serial8250_handle_irq.part.0+0x24/0x330 drivers/tty/serial/8250/8250_port.c:1823
 #4: ffff8880a905e090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref+0x22/0x90 drivers/tty/tty_ldisc.c:288

stack backtrace:
CPU: 1 PID: 9605 Comm: syz-executor826 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 print_usage_bug.cold+0x327/0x378 kernel/locking/lockdep.c:3101
 valid_state kernel/locking/lockdep.c:3112 [inline]
 mark_lock_irq kernel/locking/lockdep.c:3309 [inline]
 mark_lock+0xbb4/0x1220 kernel/locking/lockdep.c:3666
 mark_usage kernel/locking/lockdep.c:3554 [inline]
 __lock_acquire+0x1e55/0x4a00 kernel/locking/lockdep.c:3909
 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485
 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
 _raw_read_lock+0x32/0x50 kernel/locking/spinlock.c:223
 sp_get.isra.0+0x1d/0xf0 drivers/net/ppp/ppp_synctty.c:138
 sixpack_write_wakeup+0x25/0x340 drivers/net/hamradio/6pack.c:402
 tty_wakeup+0xe9/0x120 drivers/tty/tty_io.c:536
 tty_port_default_wakeup+0x2b/0x40 drivers/tty/tty_port.c:50
 tty_port_tty_wakeup+0x57/0x70 drivers/tty/tty_port.c:387
 uart_write_wakeup+0x46/0x70 drivers/tty/serial/serial_core.c:104
 serial8250_tx_chars+0x495/0xaf0 drivers/tty/serial/8250/8250_port.c:1761
 serial8250_handle_irq.part.0+0x2a2/0x330 drivers/tty/serial/8250/8250_port.c:1834
 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1820 [inline]
 serial8250_default_handle_irq+0xc0/0x150 drivers/tty/serial/8250/8250_port.c:1850
 serial8250_interrupt+0xf1/0x1a0 drivers/tty/serial/8250/8250_core.c:126
 __handle_irq_event_percpu+0x15d/0x970 kernel/irq/handle.c:149
 handle_irq_event_percpu+0x74/0x160 kernel/irq/handle.c:189
 handle_irq_event+0xa7/0x134 kernel/irq/handle.c:206
 handle_edge_irq+0x25e/0x8d0 kernel/irq/chip.c:830
 generic_handle_irq_desc include/linux/irqdesc.h:156 [inline]
 do_IRQ+0xde/0x280 arch/x86/kernel/irq.c:250
 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:607
 </IRQ>
RIP: 0010:cpu_relax arch/x86/include/asm/processor.h:685 [inline]
RIP: 0010:mutex_spin_on_owner+0x247/0x330 kernel/locking/mutex.c:579
Code: c3 be 08 00 00 00 4c 89 e7 e8 e5 06 59 00 4c 89 e0 48 c1 e8 03 42 80 3c 38 00 0f 85 e1 00 00 00 49 8b 04 24 a8 01 75 96 f3 90 <e9> 2f fe ff ff 0f 0b e8 0d 19 09 00 84 c0 0f 85 ff fd ff ff 48 c7
RSP: 0018:ffffc90001eafa20 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffd7
RAX: 0000000000000000 RBX: ffff88809fd9e0c0 RCX: 1ffffffff13266dd
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
RBP: ffffc90001eafa60 R08: 1ffff11013d22898 R09: ffffed1013d22899
R10: ffffed1013d22898 R11: ffff88809e9144c7 R12: ffff8880a905e138
R13: ffff88809e9144c0 R14: 0000000000000000 R15: dffffc0000000000
 mutex_optimistic_spin kernel/locking/mutex.c:673 [inline]
 __mutex_lock_common kernel/locking/mutex.c:962 [inline]
 __mutex_lock+0x32b/0x13c0 kernel/locking/mutex.c:1106
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1121
 tty_lock+0xc7/0x130 drivers/tty/tty_mutex.c:19
 tty_release+0xb5/0xe90 drivers/tty/tty_io.c:1665
 __fput+0x2ff/0x890 fs/file_table.c:280
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x8e7/0x2ef0 kernel/exit.c:797
 do_group_exit+0x135/0x360 kernel/exit.c:895
 __do_sys_exit_group kernel/exit.c:906 [inline]
 __se_sys_exit_group kernel/exit.c:904 [inline]
 __x64_sys_exit_group+0x44/0x50 kernel/exit.c:904
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x43fef8
Code: Bad RIP value.
RSP: 002b:00007ffdb07d2338 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043fef8
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00000000004bf730 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000

Fixes: 6e4e2f8 ("6pack,mkiss: fix lock inconsistency")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Apr 16, 2020
[ Upstream commit 42ffb0b ]

There exists a deadlock with range_cyclic that has existed forever.  If
we loop around with a bio already built we could deadlock with a writer
who has the page locked that we're attempting to write but is waiting on
a page in our bio to be written out.  The task traces are as follows

  PID: 1329874  TASK: ffff889ebcdf3800  CPU: 33  COMMAND: "kworker/u113:5"
   #0 [ffffc900297bb658] __schedule at ffffffff81a4c33f
   #1 [ffffc900297bb6e0] schedule at ffffffff81a4c6e3
   #2 [ffffc900297bb6f8] io_schedule at ffffffff81a4ca42
   #3 [ffffc900297bb708] __lock_page at ffffffff811f145b
   #4 [ffffc900297bb798] __process_pages_contig at ffffffff814bc502
   #5 [ffffc900297bb8c8] lock_delalloc_pages at ffffffff814bc684
   ayufan-rock64#6 [ffffc900297bb900] find_lock_delalloc_range at ffffffff814be9ff
   ayufan-rock64#7 [ffffc900297bb9a0] writepage_delalloc at ffffffff814bebd0
   ayufan-rock64#8 [ffffc900297bba18] __extent_writepage at ffffffff814bfbf2
   ayufan-rock64#9 [ffffc900297bba98] extent_write_cache_pages at ffffffff814bffbd

  PID: 2167901  TASK: ffff889dc6a59c00  CPU: 14  COMMAND:
  "aio-dio-invalid"
   #0 [ffffc9003b50bb18] __schedule at ffffffff81a4c33f
   #1 [ffffc9003b50bba0] schedule at ffffffff81a4c6e3
   #2 [ffffc9003b50bbb8] io_schedule at ffffffff81a4ca42
   #3 [ffffc9003b50bbc8] wait_on_page_bit at ffffffff811f24d6
   #4 [ffffc9003b50bc60] prepare_pages at ffffffff814b05a7
   #5 [ffffc9003b50bcd8] btrfs_buffered_write at ffffffff814b1359
   ayufan-rock64#6 [ffffc9003b50bdb0] btrfs_file_write_iter at ffffffff814b5933
   ayufan-rock64#7 [ffffc9003b50be38] new_sync_write at ffffffff8128f6a8
   ayufan-rock64#8 [ffffc9003b50bec8] vfs_write at ffffffff81292b9d
   ayufan-rock64#9 [ffffc9003b50bf00] ksys_pwrite64 at ffffffff81293032

I used drgn to find the respective pages we were stuck on

page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901
page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874

As you can see the kworker is waiting for bit 0 (PG_locked) on index
7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index
8148.  aio-dio-invalid has 7680, and the kworker epd looks like the
following

  crash> struct extent_page_data ffffc900297bbbb0
  struct extent_page_data {
    bio = 0xffff889f747ed830,
    tree = 0xffff889eed6ba448,
    extent_locked = 0,
    sync_io = 0
  }

Probably worth mentioning as well that it waits for writeback of the
page to complete while holding a lock on it (at prepare_pages()).

Using drgn I walked the bio pages looking for page
0xffffea00fbfc7500 which is the one we're waiting for writeback on

  bio = Object(prog, 'struct bio', address=0xffff889f747ed830)
  for i in range(0, bio.bi_vcnt.value_()):
      bv = bio.bi_io_vec[i]
      if bv.bv_page.value_() == 0xffffea00fbfc7500:
	  print("FOUND IT")

which validated what I suspected.

The fix for this is simple, flush the epd before we loop back around to
the beginning of the file during writeout.

Fixes: b293f02 ("Btrfs: Add writepages support")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Apr 16, 2020
[ Upstream commit 6c5d911 ]

journal_head::b_transaction and journal_head::b_next_transaction could
be accessed concurrently as noticed by KCSAN,

 LTP: starting fsync04
 /dev/zero: Can't open blockdev
 EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem
 EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null)
 ==================================================================
 BUG: KCSAN: data-race in __jbd2_journal_refile_buffer [jbd2] / jbd2_write_access_granted [jbd2]

 write to 0xffff99f9b1bd0e30 of 8 bytes by task 25721 on cpu 70:
  __jbd2_journal_refile_buffer+0xdd/0x210 [jbd2]
  __jbd2_journal_refile_buffer at fs/jbd2/transaction.c:2569
  jbd2_journal_commit_transaction+0x2d15/0x3f20 [jbd2]
  (inlined by) jbd2_journal_commit_transaction at fs/jbd2/commit.c:1034
  kjournald2+0x13b/0x450 [jbd2]
  kthread+0x1cd/0x1f0
  ret_from_fork+0x27/0x50

 read to 0xffff99f9b1bd0e30 of 8 bytes by task 25724 on cpu 68:
  jbd2_write_access_granted+0x1b2/0x250 [jbd2]
  jbd2_write_access_granted at fs/jbd2/transaction.c:1155
  jbd2_journal_get_write_access+0x2c/0x60 [jbd2]
  __ext4_journal_get_write_access+0x50/0x90 [ext4]
  ext4_mb_mark_diskspace_used+0x158/0x620 [ext4]
  ext4_mb_new_blocks+0x54f/0xca0 [ext4]
  ext4_ind_map_blocks+0xc79/0x1b40 [ext4]
  ext4_map_blocks+0x3b4/0x950 [ext4]
  _ext4_get_block+0xfc/0x270 [ext4]
  ext4_get_block+0x3b/0x50 [ext4]
  __block_write_begin_int+0x22e/0xae0
  __block_write_begin+0x39/0x50
  ext4_write_begin+0x388/0xb50 [ext4]
  generic_perform_write+0x15d/0x290
  ext4_buffered_write_iter+0x11f/0x210 [ext4]
  ext4_file_write_iter+0xce/0x9e0 [ext4]
  new_sync_write+0x29c/0x3b0
  __vfs_write+0x92/0xa0
  vfs_write+0x103/0x260
  ksys_write+0x9d/0x130
  __x64_sys_write+0x4c/0x60
  do_syscall_64+0x91/0xb05
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 5 locks held by fsync04/25724:
  #0: ffff99f9911093f8 (sb_writers#13){.+.+}, at: vfs_write+0x21c/0x260
  #1: ffff99f9db4c0348 (&sb->s_type->i_mutex_key#15){+.+.}, at: ext4_buffered_write_iter+0x65/0x210 [ext4]
  #2: ffff99f5e7dfcf58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2]
  #3: ffff99f9db4c0168 (&ei->i_data_sem){++++}, at: ext4_map_blocks+0x176/0x950 [ext4]
  #4: ffffffff99086b40 (rcu_read_lock){....}, at: jbd2_write_access_granted+0x4e/0x250 [jbd2]
 irq event stamp: 1407125
 hardirqs last  enabled at (1407125): [<ffffffff980da9b7>] __find_get_block+0x107/0x790
 hardirqs last disabled at (1407124): [<ffffffff980da8f9>] __find_get_block+0x49/0x790
 softirqs last  enabled at (1405528): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c
 softirqs last disabled at (1405521): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 68 PID: 25724 Comm: fsync04 Tainted: G L 5.6.0-rc2-next-20200221+ ayufan-rock64#7
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

The plain reads are outside of jh->b_state_lock critical section which result
in data races. Fix them by adding pairs of READ|WRITE_ONCE().

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Qian Cai <cai@lca.pw>
Link: https://lore.kernel.org/r/20200222043111.2227-1-cai@lca.pw
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Oct 7, 2023
[ Upstream commit ef23cb5 ]

While debugging a segfault on 'perf lock contention' without an
available perf.data file I noticed that it was basically calling:

	perf_session__delete(ERR_PTR(-1))

Resulting in:

  (gdb) run lock contention
  Starting program: /root/bin/perf lock contention
  [Thread debugging using libthread_db enabled]
  Using host libthread_db library "/lib64/libthread_db.so.1".
  failed to open perf.data: No such file or directory  (try 'perf record' first)
  Initializing perf session failed

  Program received signal SIGSEGV, Segmentation fault.
  0x00000000005e7515 in auxtrace__free (session=0xffffffffffffffff) at util/auxtrace.c:2858
  2858		if (!session->auxtrace)
  (gdb) p session
  $1 = (struct perf_session *) 0xffffffffffffffff
  (gdb) bt
  #0  0x00000000005e7515 in auxtrace__free (session=0xffffffffffffffff) at util/auxtrace.c:2858
  #1  0x000000000057bb4d in perf_session__delete (session=0xffffffffffffffff) at util/session.c:300
  #2  0x000000000047c421 in __cmd_contention (argc=0, argv=0x7fffffffe200) at builtin-lock.c:2161
  #3  0x000000000047dc95 in cmd_lock (argc=0, argv=0x7fffffffe200) at builtin-lock.c:2604
  #4  0x0000000000501466 in run_builtin (p=0xe597a8 <commands+552>, argc=2, argv=0x7fffffffe200) at perf.c:322
  #5  0x00000000005016d5 in handle_internal_command (argc=2, argv=0x7fffffffe200) at perf.c:375
  ayufan-rock64#6  0x0000000000501824 in run_argv (argcp=0x7fffffffe02c, argv=0x7fffffffe020) at perf.c:419
  ayufan-rock64#7  0x0000000000501b11 in main (argc=2, argv=0x7fffffffe200) at perf.c:535
  (gdb)

So just set it to NULL after using PTR_ERR(session) to decode the error
as perf_session__delete(NULL) is supported.

The same problem was found in 'perf top' after an audit of all
perf_session__new() failure handling.

Fixes: 6ef81c5 ("perf session: Return error code for perf_session__new() function on failure")
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeremie Galarneau <jeremie.galarneau@efficios.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Mamatha Inamdar <mamatha4@linux.vnet.ibm.com>
Cc: Mukesh Ojha <mojha@codeaurora.org>
Cc: Nageswara R Sastry <rnsastry@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Shawn Landden <shawn@git.icu>
Cc: Song Liu <songliubraving@fb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Link: https://lore.kernel.org/lkml/ZN4Q2rxxsL08A8rd@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Oct 7, 2023
[ Upstream commit 8fc134f ]

When the plug qdisc is used as a class of the qfq qdisc it could trigger a
UAF. This issue can be reproduced with following commands:

  tc qdisc add dev lo root handle 1: qfq
  tc class add dev lo parent 1: classid 1:1 qfq weight 1 maxpkt 512
  tc qdisc add dev lo parent 1:1 handle 2: plug
  tc filter add dev lo parent 1: basic classid 1:1
  ping -c1 127.0.0.1

and boom:

[  285.353793] BUG: KASAN: slab-use-after-free in qfq_dequeue+0xa7/0x7f0
[  285.354910] Read of size 4 at addr ffff8880bad312a8 by task ping/144
[  285.355903]
[  285.356165] CPU: 1 PID: 144 Comm: ping Not tainted 6.5.0-rc3+ #4
[  285.357112] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
[  285.358376] Call Trace:
[  285.358773]  <IRQ>
[  285.359109]  dump_stack_lvl+0x44/0x60
[  285.359708]  print_address_description.constprop.0+0x2c/0x3c0
[  285.360611]  kasan_report+0x10c/0x120
[  285.361195]  ? qfq_dequeue+0xa7/0x7f0
[  285.361780]  qfq_dequeue+0xa7/0x7f0
[  285.362342]  __qdisc_run+0xf1/0x970
[  285.362903]  net_tx_action+0x28e/0x460
[  285.363502]  __do_softirq+0x11b/0x3de
[  285.364097]  do_softirq.part.0+0x72/0x90
[  285.364721]  </IRQ>
[  285.365072]  <TASK>
[  285.365422]  __local_bh_enable_ip+0x77/0x90
[  285.366079]  __dev_queue_xmit+0x95f/0x1550
[  285.366732]  ? __pfx_csum_and_copy_from_iter+0x10/0x10
[  285.367526]  ? __pfx___dev_queue_xmit+0x10/0x10
[  285.368259]  ? __build_skb_around+0x129/0x190
[  285.368960]  ? ip_generic_getfrag+0x12c/0x170
[  285.369653]  ? __pfx_ip_generic_getfrag+0x10/0x10
[  285.370390]  ? csum_partial+0x8/0x20
[  285.370961]  ? raw_getfrag+0xe5/0x140
[  285.371559]  ip_finish_output2+0x539/0xa40
[  285.372222]  ? __pfx_ip_finish_output2+0x10/0x10
[  285.372954]  ip_output+0x113/0x1e0
[  285.373512]  ? __pfx_ip_output+0x10/0x10
[  285.374130]  ? icmp_out_count+0x49/0x60
[  285.374739]  ? __pfx_ip_finish_output+0x10/0x10
[  285.375457]  ip_push_pending_frames+0xf3/0x100
[  285.376173]  raw_sendmsg+0xef5/0x12d0
[  285.376760]  ? do_syscall_64+0x40/0x90
[  285.377359]  ? __static_call_text_end+0x136578/0x136578
[  285.378173]  ? do_syscall_64+0x40/0x90
[  285.378772]  ? kasan_enable_current+0x11/0x20
[  285.379469]  ? __pfx_raw_sendmsg+0x10/0x10
[  285.380137]  ? __sock_create+0x13e/0x270
[  285.380673]  ? __sys_socket+0xf3/0x180
[  285.381174]  ? __x64_sys_socket+0x3d/0x50
[  285.381725]  ? entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[  285.382425]  ? __rcu_read_unlock+0x48/0x70
[  285.382975]  ? ip4_datagram_release_cb+0xd8/0x380
[  285.383608]  ? __pfx_ip4_datagram_release_cb+0x10/0x10
[  285.384295]  ? preempt_count_sub+0x14/0xc0
[  285.384844]  ? __list_del_entry_valid+0x76/0x140
[  285.385467]  ? _raw_spin_lock_bh+0x87/0xe0
[  285.386014]  ? __pfx__raw_spin_lock_bh+0x10/0x10
[  285.386645]  ? release_sock+0xa0/0xd0
[  285.387148]  ? preempt_count_sub+0x14/0xc0
[  285.387712]  ? freeze_secondary_cpus+0x348/0x3c0
[  285.388341]  ? aa_sk_perm+0x177/0x390
[  285.388856]  ? __pfx_aa_sk_perm+0x10/0x10
[  285.389441]  ? check_stack_object+0x22/0x70
[  285.390032]  ? inet_send_prepare+0x2f/0x120
[  285.390603]  ? __pfx_inet_sendmsg+0x10/0x10
[  285.391172]  sock_sendmsg+0xcc/0xe0
[  285.391667]  __sys_sendto+0x190/0x230
[  285.392168]  ? __pfx___sys_sendto+0x10/0x10
[  285.392727]  ? kvm_clock_get_cycles+0x14/0x30
[  285.393328]  ? set_normalized_timespec64+0x57/0x70
[  285.393980]  ? _raw_spin_unlock_irq+0x1b/0x40
[  285.394578]  ? __x64_sys_clock_gettime+0x11c/0x160
[  285.395225]  ? __pfx___x64_sys_clock_gettime+0x10/0x10
[  285.395908]  ? _copy_to_user+0x3e/0x60
[  285.396432]  ? exit_to_user_mode_prepare+0x1a/0x120
[  285.397086]  ? syscall_exit_to_user_mode+0x22/0x50
[  285.397734]  ? do_syscall_64+0x71/0x90
[  285.398258]  __x64_sys_sendto+0x74/0x90
[  285.398786]  do_syscall_64+0x64/0x90
[  285.399273]  ? exit_to_user_mode_prepare+0x1a/0x120
[  285.399949]  ? syscall_exit_to_user_mode+0x22/0x50
[  285.400605]  ? do_syscall_64+0x71/0x90
[  285.401124]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[  285.401807] RIP: 0033:0x495726
[  285.402233] Code: ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 11 b8 2c 00 00 00 0f 09
[  285.404683] RSP: 002b:00007ffcc25fb618 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[  285.405677] RAX: ffffffffffffffda RBX: 0000000000000040 RCX: 0000000000495726
[  285.406628] RDX: 0000000000000040 RSI: 0000000002518750 RDI: 0000000000000000
[  285.407565] RBP: 00000000005205ef R08: 00000000005f8838 R09: 000000000000001c
[  285.408523] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000002517634
[  285.409460] R13: 00007ffcc25fb6f0 R14: 0000000000000003 R15: 0000000000000000
[  285.410403]  </TASK>
[  285.410704]
[  285.410929] Allocated by task 144:
[  285.411402]  kasan_save_stack+0x1e/0x40
[  285.411926]  kasan_set_track+0x21/0x30
[  285.412442]  __kasan_slab_alloc+0x55/0x70
[  285.412973]  kmem_cache_alloc_node+0x187/0x3d0
[  285.413567]  __alloc_skb+0x1b4/0x230
[  285.414060]  __ip_append_data+0x17f7/0x1b60
[  285.414633]  ip_append_data+0x97/0xf0
[  285.415144]  raw_sendmsg+0x5a8/0x12d0
[  285.415640]  sock_sendmsg+0xcc/0xe0
[  285.416117]  __sys_sendto+0x190/0x230
[  285.416626]  __x64_sys_sendto+0x74/0x90
[  285.417145]  do_syscall_64+0x64/0x90
[  285.417624]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[  285.418306]
[  285.418531] Freed by task 144:
[  285.418960]  kasan_save_stack+0x1e/0x40
[  285.419469]  kasan_set_track+0x21/0x30
[  285.419988]  kasan_save_free_info+0x27/0x40
[  285.420556]  ____kasan_slab_free+0x109/0x1a0
[  285.421146]  kmem_cache_free+0x1c2/0x450
[  285.421680]  __netif_receive_skb_core+0x2ce/0x1870
[  285.422333]  __netif_receive_skb_one_core+0x97/0x140
[  285.423003]  process_backlog+0x100/0x2f0
[  285.423537]  __napi_poll+0x5c/0x2d0
[  285.424023]  net_rx_action+0x2be/0x560
[  285.424510]  __do_softirq+0x11b/0x3de
[  285.425034]
[  285.425254] The buggy address belongs to the object at ffff8880bad31280
[  285.425254]  which belongs to the cache skbuff_head_cache of size 224
[  285.426993] The buggy address is located 40 bytes inside of
[  285.426993]  freed 224-byte region [ffff8880bad31280, ffff8880bad31360)
[  285.428572]
[  285.428798] The buggy address belongs to the physical page:
[  285.429540] page:00000000f4b77674 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xbad31
[  285.430758] flags: 0x100000000000200(slab|node=0|zone=1)
[  285.431447] page_type: 0xffffffff()
[  285.431934] raw: 0100000000000200 ffff88810094a8c0 dead000000000122 0000000000000000
[  285.432757] raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000
[  285.433562] page dumped because: kasan: bad access detected
[  285.434144]
[  285.434320] Memory state around the buggy address:
[  285.434828]  ffff8880bad31180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  285.435580]  ffff8880bad31200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  285.436264] >ffff8880bad31280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  285.436777]                                   ^
[  285.437106]  ffff8880bad31300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
[  285.437616]  ffff8880bad31380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  285.438126] ==================================================================
[  285.438662] Disabling lock debugging due to kernel taint

Fix this by:
1. Changing sch_plug's .peek handler to qdisc_peek_dequeued(), a
function compatible with non-work-conserving qdiscs
2. Checking the return value of qdisc_dequeue_peeked() in sch_qfq.

Fixes: 462dbc9 ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost")
Reported-by: valis <sec@valis.email>
Signed-off-by: valis <sec@valis.email>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20230901162237.11525-1-jhs@mojatatu.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Oct 7, 2023
[ Upstream commit 7962ef1 ]

In 3cb4d5e ("perf trace: Free syscall tp fields in
evsel->priv") it only was freeing if strcmp(evsel->tp_format->system,
"syscalls") returned zero, while the corresponding initialization of
evsel->priv was being performed if it was _not_ zero, i.e. if the tp
system wasn't 'syscalls'.

Just stop looking for that and free it if evsel->priv was set, which
should be equivalent.

Also use the pre-existing evsel_trace__delete() function.

This resolves these leaks, detected with:

  $ make EXTRA_CFLAGS="-fsanitize=address" BUILD_BPF_SKEL=1 CORESIGHT=1 O=/tmp/build/perf-tools-next -C tools/perf install-bin

  =================================================================
  ==481565==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 40 byte(s) in 1 object(s) allocated from:
      #0 0x7f7343cba097 in calloc (/lib64/libasan.so.8+0xba097)
      #1 0x987966 in zalloc (/home/acme/bin/perf+0x987966)
      #2 0x52f9b9 in evsel_trace__new /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:307
      #3 0x52f9b9 in evsel__syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:333
      #4 0x52f9b9 in evsel__init_raw_syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:458
      #5 0x52f9b9 in perf_evsel__raw_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:480
      ayufan-rock64#6 0x540e8b in trace__add_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3212
      ayufan-rock64#7 0x540e8b in trace__run /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3891
      ayufan-rock64#8 0x540e8b in cmd_trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:5156
      ayufan-rock64#9 0x5ef262 in run_builtin /home/acme/git/perf-tools-next/tools/perf/perf.c:323
      ayufan-rock64#10 0x4196da in handle_internal_command /home/acme/git/perf-tools-next/tools/perf/perf.c:377
      ayufan-rock64#11 0x4196da in run_argv /home/acme/git/perf-tools-next/tools/perf/perf.c:421
      ayufan-rock64#12 0x4196da in main /home/acme/git/perf-tools-next/tools/perf/perf.c:537
      ayufan-rock64#13 0x7f7342c4a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f)

  Direct leak of 40 byte(s) in 1 object(s) allocated from:
      #0 0x7f7343cba097 in calloc (/lib64/libasan.so.8+0xba097)
      #1 0x987966 in zalloc (/home/acme/bin/perf+0x987966)
      #2 0x52f9b9 in evsel_trace__new /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:307
      #3 0x52f9b9 in evsel__syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:333
      #4 0x52f9b9 in evsel__init_raw_syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:458
      #5 0x52f9b9 in perf_evsel__raw_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:480
      ayufan-rock64#6 0x540dd1 in trace__add_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3205
      ayufan-rock64#7 0x540dd1 in trace__run /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3891
      ayufan-rock64#8 0x540dd1 in cmd_trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:5156
      ayufan-rock64#9 0x5ef262 in run_builtin /home/acme/git/perf-tools-next/tools/perf/perf.c:323
      ayufan-rock64#10 0x4196da in handle_internal_command /home/acme/git/perf-tools-next/tools/perf/perf.c:377
      ayufan-rock64#11 0x4196da in run_argv /home/acme/git/perf-tools-next/tools/perf/perf.c:421
      ayufan-rock64#12 0x4196da in main /home/acme/git/perf-tools-next/tools/perf/perf.c:537
      ayufan-rock64#13 0x7f7342c4a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f)

  SUMMARY: AddressSanitizer: 80 byte(s) leaked in 2 allocation(s).
  [root@quaco ~]#

With this we plug all leaks with "perf trace sleep 1".

Fixes: 3cb4d5e ("perf trace: Free syscall tp fields in evsel->priv")
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Link: https://lore.kernel.org/lkml/20230719202951.534582-5-acme@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Oct 7, 2023
[ Upstream commit ef23cb5 ]

While debugging a segfault on 'perf lock contention' without an
available perf.data file I noticed that it was basically calling:

	perf_session__delete(ERR_PTR(-1))

Resulting in:

  (gdb) run lock contention
  Starting program: /root/bin/perf lock contention
  [Thread debugging using libthread_db enabled]
  Using host libthread_db library "/lib64/libthread_db.so.1".
  failed to open perf.data: No such file or directory  (try 'perf record' first)
  Initializing perf session failed

  Program received signal SIGSEGV, Segmentation fault.
  0x00000000005e7515 in auxtrace__free (session=0xffffffffffffffff) at util/auxtrace.c:2858
  2858		if (!session->auxtrace)
  (gdb) p session
  $1 = (struct perf_session *) 0xffffffffffffffff
  (gdb) bt
  #0  0x00000000005e7515 in auxtrace__free (session=0xffffffffffffffff) at util/auxtrace.c:2858
  #1  0x000000000057bb4d in perf_session__delete (session=0xffffffffffffffff) at util/session.c:300
  #2  0x000000000047c421 in __cmd_contention (argc=0, argv=0x7fffffffe200) at builtin-lock.c:2161
  #3  0x000000000047dc95 in cmd_lock (argc=0, argv=0x7fffffffe200) at builtin-lock.c:2604
  #4  0x0000000000501466 in run_builtin (p=0xe597a8 <commands+552>, argc=2, argv=0x7fffffffe200) at perf.c:322
  #5  0x00000000005016d5 in handle_internal_command (argc=2, argv=0x7fffffffe200) at perf.c:375
  ayufan-rock64#6  0x0000000000501824 in run_argv (argcp=0x7fffffffe02c, argv=0x7fffffffe020) at perf.c:419
  ayufan-rock64#7  0x0000000000501b11 in main (argc=2, argv=0x7fffffffe200) at perf.c:535
  (gdb)

So just set it to NULL after using PTR_ERR(session) to decode the error
as perf_session__delete(NULL) is supported.

The same problem was found in 'perf top' after an audit of all
perf_session__new() failure handling.

Fixes: 6ef81c5 ("perf session: Return error code for perf_session__new() function on failure")
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeremie Galarneau <jeremie.galarneau@efficios.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Mamatha Inamdar <mamatha4@linux.vnet.ibm.com>
Cc: Mukesh Ojha <mojha@codeaurora.org>
Cc: Nageswara R Sastry <rnsastry@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Shawn Landden <shawn@git.icu>
Cc: Song Liu <songliubraving@fb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Link: https://lore.kernel.org/lkml/ZN4Q2rxxsL08A8rd@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Oct 7, 2023
[ Upstream commit 8fc134f ]

When the plug qdisc is used as a class of the qfq qdisc it could trigger a
UAF. This issue can be reproduced with following commands:

  tc qdisc add dev lo root handle 1: qfq
  tc class add dev lo parent 1: classid 1:1 qfq weight 1 maxpkt 512
  tc qdisc add dev lo parent 1:1 handle 2: plug
  tc filter add dev lo parent 1: basic classid 1:1
  ping -c1 127.0.0.1

and boom:

[  285.353793] BUG: KASAN: slab-use-after-free in qfq_dequeue+0xa7/0x7f0
[  285.354910] Read of size 4 at addr ffff8880bad312a8 by task ping/144
[  285.355903]
[  285.356165] CPU: 1 PID: 144 Comm: ping Not tainted 6.5.0-rc3+ #4
[  285.357112] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
[  285.358376] Call Trace:
[  285.358773]  <IRQ>
[  285.359109]  dump_stack_lvl+0x44/0x60
[  285.359708]  print_address_description.constprop.0+0x2c/0x3c0
[  285.360611]  kasan_report+0x10c/0x120
[  285.361195]  ? qfq_dequeue+0xa7/0x7f0
[  285.361780]  qfq_dequeue+0xa7/0x7f0
[  285.362342]  __qdisc_run+0xf1/0x970
[  285.362903]  net_tx_action+0x28e/0x460
[  285.363502]  __do_softirq+0x11b/0x3de
[  285.364097]  do_softirq.part.0+0x72/0x90
[  285.364721]  </IRQ>
[  285.365072]  <TASK>
[  285.365422]  __local_bh_enable_ip+0x77/0x90
[  285.366079]  __dev_queue_xmit+0x95f/0x1550
[  285.366732]  ? __pfx_csum_and_copy_from_iter+0x10/0x10
[  285.367526]  ? __pfx___dev_queue_xmit+0x10/0x10
[  285.368259]  ? __build_skb_around+0x129/0x190
[  285.368960]  ? ip_generic_getfrag+0x12c/0x170
[  285.369653]  ? __pfx_ip_generic_getfrag+0x10/0x10
[  285.370390]  ? csum_partial+0x8/0x20
[  285.370961]  ? raw_getfrag+0xe5/0x140
[  285.371559]  ip_finish_output2+0x539/0xa40
[  285.372222]  ? __pfx_ip_finish_output2+0x10/0x10
[  285.372954]  ip_output+0x113/0x1e0
[  285.373512]  ? __pfx_ip_output+0x10/0x10
[  285.374130]  ? icmp_out_count+0x49/0x60
[  285.374739]  ? __pfx_ip_finish_output+0x10/0x10
[  285.375457]  ip_push_pending_frames+0xf3/0x100
[  285.376173]  raw_sendmsg+0xef5/0x12d0
[  285.376760]  ? do_syscall_64+0x40/0x90
[  285.377359]  ? __static_call_text_end+0x136578/0x136578
[  285.378173]  ? do_syscall_64+0x40/0x90
[  285.378772]  ? kasan_enable_current+0x11/0x20
[  285.379469]  ? __pfx_raw_sendmsg+0x10/0x10
[  285.380137]  ? __sock_create+0x13e/0x270
[  285.380673]  ? __sys_socket+0xf3/0x180
[  285.381174]  ? __x64_sys_socket+0x3d/0x50
[  285.381725]  ? entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[  285.382425]  ? __rcu_read_unlock+0x48/0x70
[  285.382975]  ? ip4_datagram_release_cb+0xd8/0x380
[  285.383608]  ? __pfx_ip4_datagram_release_cb+0x10/0x10
[  285.384295]  ? preempt_count_sub+0x14/0xc0
[  285.384844]  ? __list_del_entry_valid+0x76/0x140
[  285.385467]  ? _raw_spin_lock_bh+0x87/0xe0
[  285.386014]  ? __pfx__raw_spin_lock_bh+0x10/0x10
[  285.386645]  ? release_sock+0xa0/0xd0
[  285.387148]  ? preempt_count_sub+0x14/0xc0
[  285.387712]  ? freeze_secondary_cpus+0x348/0x3c0
[  285.388341]  ? aa_sk_perm+0x177/0x390
[  285.388856]  ? __pfx_aa_sk_perm+0x10/0x10
[  285.389441]  ? check_stack_object+0x22/0x70
[  285.390032]  ? inet_send_prepare+0x2f/0x120
[  285.390603]  ? __pfx_inet_sendmsg+0x10/0x10
[  285.391172]  sock_sendmsg+0xcc/0xe0
[  285.391667]  __sys_sendto+0x190/0x230
[  285.392168]  ? __pfx___sys_sendto+0x10/0x10
[  285.392727]  ? kvm_clock_get_cycles+0x14/0x30
[  285.393328]  ? set_normalized_timespec64+0x57/0x70
[  285.393980]  ? _raw_spin_unlock_irq+0x1b/0x40
[  285.394578]  ? __x64_sys_clock_gettime+0x11c/0x160
[  285.395225]  ? __pfx___x64_sys_clock_gettime+0x10/0x10
[  285.395908]  ? _copy_to_user+0x3e/0x60
[  285.396432]  ? exit_to_user_mode_prepare+0x1a/0x120
[  285.397086]  ? syscall_exit_to_user_mode+0x22/0x50
[  285.397734]  ? do_syscall_64+0x71/0x90
[  285.398258]  __x64_sys_sendto+0x74/0x90
[  285.398786]  do_syscall_64+0x64/0x90
[  285.399273]  ? exit_to_user_mode_prepare+0x1a/0x120
[  285.399949]  ? syscall_exit_to_user_mode+0x22/0x50
[  285.400605]  ? do_syscall_64+0x71/0x90
[  285.401124]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[  285.401807] RIP: 0033:0x495726
[  285.402233] Code: ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 11 b8 2c 00 00 00 0f 09
[  285.404683] RSP: 002b:00007ffcc25fb618 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[  285.405677] RAX: ffffffffffffffda RBX: 0000000000000040 RCX: 0000000000495726
[  285.406628] RDX: 0000000000000040 RSI: 0000000002518750 RDI: 0000000000000000
[  285.407565] RBP: 00000000005205ef R08: 00000000005f8838 R09: 000000000000001c
[  285.408523] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000002517634
[  285.409460] R13: 00007ffcc25fb6f0 R14: 0000000000000003 R15: 0000000000000000
[  285.410403]  </TASK>
[  285.410704]
[  285.410929] Allocated by task 144:
[  285.411402]  kasan_save_stack+0x1e/0x40
[  285.411926]  kasan_set_track+0x21/0x30
[  285.412442]  __kasan_slab_alloc+0x55/0x70
[  285.412973]  kmem_cache_alloc_node+0x187/0x3d0
[  285.413567]  __alloc_skb+0x1b4/0x230
[  285.414060]  __ip_append_data+0x17f7/0x1b60
[  285.414633]  ip_append_data+0x97/0xf0
[  285.415144]  raw_sendmsg+0x5a8/0x12d0
[  285.415640]  sock_sendmsg+0xcc/0xe0
[  285.416117]  __sys_sendto+0x190/0x230
[  285.416626]  __x64_sys_sendto+0x74/0x90
[  285.417145]  do_syscall_64+0x64/0x90
[  285.417624]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[  285.418306]
[  285.418531] Freed by task 144:
[  285.418960]  kasan_save_stack+0x1e/0x40
[  285.419469]  kasan_set_track+0x21/0x30
[  285.419988]  kasan_save_free_info+0x27/0x40
[  285.420556]  ____kasan_slab_free+0x109/0x1a0
[  285.421146]  kmem_cache_free+0x1c2/0x450
[  285.421680]  __netif_receive_skb_core+0x2ce/0x1870
[  285.422333]  __netif_receive_skb_one_core+0x97/0x140
[  285.423003]  process_backlog+0x100/0x2f0
[  285.423537]  __napi_poll+0x5c/0x2d0
[  285.424023]  net_rx_action+0x2be/0x560
[  285.424510]  __do_softirq+0x11b/0x3de
[  285.425034]
[  285.425254] The buggy address belongs to the object at ffff8880bad31280
[  285.425254]  which belongs to the cache skbuff_head_cache of size 224
[  285.426993] The buggy address is located 40 bytes inside of
[  285.426993]  freed 224-byte region [ffff8880bad31280, ffff8880bad31360)
[  285.428572]
[  285.428798] The buggy address belongs to the physical page:
[  285.429540] page:00000000f4b77674 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xbad31
[  285.430758] flags: 0x100000000000200(slab|node=0|zone=1)
[  285.431447] page_type: 0xffffffff()
[  285.431934] raw: 0100000000000200 ffff88810094a8c0 dead000000000122 0000000000000000
[  285.432757] raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000
[  285.433562] page dumped because: kasan: bad access detected
[  285.434144]
[  285.434320] Memory state around the buggy address:
[  285.434828]  ffff8880bad31180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  285.435580]  ffff8880bad31200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  285.436264] >ffff8880bad31280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  285.436777]                                   ^
[  285.437106]  ffff8880bad31300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
[  285.437616]  ffff8880bad31380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  285.438126] ==================================================================
[  285.438662] Disabling lock debugging due to kernel taint

Fix this by:
1. Changing sch_plug's .peek handler to qdisc_peek_dequeued(), a
function compatible with non-work-conserving qdiscs
2. Checking the return value of qdisc_dequeue_peeked() in sch_qfq.

Fixes: 462dbc9 ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost")
Reported-by: valis <sec@valis.email>
Signed-off-by: valis <sec@valis.email>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20230901162237.11525-1-jhs@mojatatu.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Oct 7, 2023
[ Upstream commit af42269 ]

For cases where icc_bw_set() can be called in callbaths that could
deadlock against shrinker/reclaim, such as runpm resume, we need to
decouple the icc locking.  Introduce a new icc_bw_lock for cases where
we need to serialize bw aggregation and update to decouple that from
paths that require memory allocation such as node/link creation/
destruction.

Fixes this lockdep splat:

   ======================================================
   WARNING: possible circular locking dependency detected
   6.2.0-rc8-debug+ #554 Not tainted
   ------------------------------------------------------
   ring0/132 is trying to acquire lock:
   ffffff80871916d0 (&gmu->lock){+.+.}-{3:3}, at: a6xx_pm_resume+0xf0/0x234

   but task is already holding lock:
   ffffffdb5aee57e8 (dma_fence_map){++++}-{0:0}, at: msm_job_run+0x68/0x150

   which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

   -> #4 (dma_fence_map){++++}-{0:0}:
          __dma_fence_might_wait+0x74/0xc0
          dma_resv_lockdep+0x1f4/0x2f4
          do_one_initcall+0x104/0x2bc
          kernel_init_freeable+0x344/0x34c
          kernel_init+0x30/0x134
          ret_from_fork+0x10/0x20

   -> #3 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}:
          fs_reclaim_acquire+0x80/0xa8
          slab_pre_alloc_hook.constprop.0+0x40/0x25c
          __kmem_cache_alloc_node+0x60/0x1cc
          __kmalloc+0xd8/0x100
          topology_parse_cpu_capacity+0x8c/0x178
          get_cpu_for_node+0x88/0xc4
          parse_cluster+0x1b0/0x28c
          parse_cluster+0x8c/0x28c
          init_cpu_topology+0x168/0x188
          smp_prepare_cpus+0x24/0xf8
          kernel_init_freeable+0x18c/0x34c
          kernel_init+0x30/0x134
          ret_from_fork+0x10/0x20

   -> #2 (fs_reclaim){+.+.}-{0:0}:
          __fs_reclaim_acquire+0x3c/0x48
          fs_reclaim_acquire+0x54/0xa8
          slab_pre_alloc_hook.constprop.0+0x40/0x25c
          __kmem_cache_alloc_node+0x60/0x1cc
          __kmalloc+0xd8/0x100
          kzalloc.constprop.0+0x14/0x20
          icc_node_create_nolock+0x4c/0xc4
          icc_node_create+0x38/0x58
          qcom_icc_rpmh_probe+0x1b8/0x248
          platform_probe+0x70/0xc4
          really_probe+0x158/0x290
          __driver_probe_device+0xc8/0xe0
          driver_probe_device+0x44/0x100
          __driver_attach+0xf8/0x108
          bus_for_each_dev+0x78/0xc4
          driver_attach+0x2c/0x38
          bus_add_driver+0xd0/0x1d8
          driver_register+0xbc/0xf8
          __platform_driver_register+0x30/0x3c
          qnoc_driver_init+0x24/0x30
          do_one_initcall+0x104/0x2bc
          kernel_init_freeable+0x344/0x34c
          kernel_init+0x30/0x134
          ret_from_fork+0x10/0x20

   -> #1 (icc_lock){+.+.}-{3:3}:
          __mutex_lock+0xcc/0x3c8
          mutex_lock_nested+0x30/0x44
          icc_set_bw+0x88/0x2b4
          _set_opp_bw+0x8c/0xd8
          _set_opp+0x19c/0x300
          dev_pm_opp_set_opp+0x84/0x94
          a6xx_gmu_resume+0x18c/0x804
          a6xx_pm_resume+0xf8/0x234
          adreno_runtime_resume+0x2c/0x38
          pm_generic_runtime_resume+0x30/0x44
          __rpm_callback+0x15c/0x174
          rpm_callback+0x78/0x7c
          rpm_resume+0x318/0x524
          __pm_runtime_resume+0x78/0xbc
          adreno_load_gpu+0xc4/0x17c
          msm_open+0x50/0x120
          drm_file_alloc+0x17c/0x228
          drm_open_helper+0x74/0x118
          drm_open+0xa0/0x144
          drm_stub_open+0xd4/0xe4
          chrdev_open+0x1b8/0x1e4
          do_dentry_open+0x2f8/0x38c
          vfs_open+0x34/0x40
          path_openat+0x64c/0x7b4
          do_filp_open+0x54/0xc4
          do_sys_openat2+0x9c/0x100
          do_sys_open+0x50/0x7c
          __arm64_sys_openat+0x28/0x34
          invoke_syscall+0x8c/0x128
          el0_svc_common.constprop.0+0xa0/0x11c
          do_el0_svc+0xac/0xbc
          el0_svc+0x48/0xa0
          el0t_64_sync_handler+0xac/0x13c
          el0t_64_sync+0x190/0x194

   -> #0 (&gmu->lock){+.+.}-{3:3}:
          __lock_acquire+0xe00/0x1060
          lock_acquire+0x1e0/0x2f8
          __mutex_lock+0xcc/0x3c8
          mutex_lock_nested+0x30/0x44
          a6xx_pm_resume+0xf0/0x234
          adreno_runtime_resume+0x2c/0x38
          pm_generic_runtime_resume+0x30/0x44
          __rpm_callback+0x15c/0x174
          rpm_callback+0x78/0x7c
          rpm_resume+0x318/0x524
          __pm_runtime_resume+0x78/0xbc
          pm_runtime_get_sync.isra.0+0x14/0x20
          msm_gpu_submit+0x58/0x178
          msm_job_run+0x78/0x150
          drm_sched_main+0x290/0x370
          kthread+0xf0/0x100
          ret_from_fork+0x10/0x20

   other info that might help us debug this:

   Chain exists of:
     &gmu->lock --> mmu_notifier_invalidate_range_start --> dma_fence_map

    Possible unsafe locking scenario:

          CPU0                    CPU1
          ----                    ----
     lock(dma_fence_map);
                                  lock(mmu_notifier_invalidate_range_start);
                                  lock(dma_fence_map);
     lock(&gmu->lock);

    *** DEADLOCK ***

   2 locks held by ring0/132:
    #0: ffffff8087191170 (&gpu->lock){+.+.}-{3:3}, at: msm_job_run+0x64/0x150
    #1: ffffffdb5aee57e8 (dma_fence_map){++++}-{0:0}, at: msm_job_run+0x68/0x150

   stack backtrace:
   CPU: 7 PID: 132 Comm: ring0 Not tainted 6.2.0-rc8-debug+ #554
   Hardware name: Google Lazor (rev1 - 2) with LTE (DT)
   Call trace:
    dump_backtrace.part.0+0xb4/0xf8
    show_stack+0x20/0x38
    dump_stack_lvl+0x9c/0xd0
    dump_stack+0x18/0x34
    print_circular_bug+0x1b4/0x1f0
    check_noncircular+0x78/0xac
    __lock_acquire+0xe00/0x1060
    lock_acquire+0x1e0/0x2f8
    __mutex_lock+0xcc/0x3c8
    mutex_lock_nested+0x30/0x44
    a6xx_pm_resume+0xf0/0x234
    adreno_runtime_resume+0x2c/0x38
    pm_generic_runtime_resume+0x30/0x44
    __rpm_callback+0x15c/0x174
    rpm_callback+0x78/0x7c
    rpm_resume+0x318/0x524
    __pm_runtime_resume+0x78/0xbc
    pm_runtime_get_sync.isra.0+0x14/0x20
    msm_gpu_submit+0x58/0x178
    msm_job_run+0x78/0x150
    drm_sched_main+0x290/0x370
    kthread+0xf0/0x100
    ret_from_fork+0x10/0x20

Signed-off-by: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20230807171148.210181-7-robdclark@gmail.com
Signed-off-by: Georgi Djakov <djakov@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
[ Upstream commit a154f5f ]

The following call trace shows a deadlock issue due to recursive locking of
mutex "device_mutex". First lock acquire is in target_for_each_device() and
second in target_free_device().

 PID: 148266   TASK: ffff8be21ffb5d00  CPU: 10   COMMAND: "iscsi_ttx"
  #0 [ffffa2bfc9ec3b18] __schedule at ffffffffa8060e7f
  #1 [ffffa2bfc9ec3ba0] schedule at ffffffffa8061224
  #2 [ffffa2bfc9ec3bb8] schedule_preempt_disabled at ffffffffa80615ee
  #3 [ffffa2bfc9ec3bc8] __mutex_lock at ffffffffa8062fd7
  #4 [ffffa2bfc9ec3c40] __mutex_lock_slowpath at ffffffffa80631d3
  #5 [ffffa2bfc9ec3c50] mutex_lock at ffffffffa806320c
  ayufan-rock64#6 [ffffa2bfc9ec3c68] target_free_device at ffffffffc0935998 [target_core_mod]
  ayufan-rock64#7 [ffffa2bfc9ec3c90] target_core_dev_release at ffffffffc092f975 [target_core_mod]
  ayufan-rock64#8 [ffffa2bfc9ec3ca0] config_item_put at ffffffffa79d250f
  ayufan-rock64#9 [ffffa2bfc9ec3cd0] config_item_put at ffffffffa79d2583
 ayufan-rock64#10 [ffffa2bfc9ec3ce0] target_devices_idr_iter at ffffffffc0933f3a [target_core_mod]
 ayufan-rock64#11 [ffffa2bfc9ec3d00] idr_for_each at ffffffffa803f6fc
 ayufan-rock64#12 [ffffa2bfc9ec3d60] target_for_each_device at ffffffffc0935670 [target_core_mod]
 ayufan-rock64#13 [ffffa2bfc9ec3d98] transport_deregister_session at ffffffffc0946408 [target_core_mod]
 ayufan-rock64#14 [ffffa2bfc9ec3dc8] iscsit_close_session at ffffffffc09a44a6 [iscsi_target_mod]
 ayufan-rock64#15 [ffffa2bfc9ec3df0] iscsit_close_connection at ffffffffc09a4a88 [iscsi_target_mod]
 ayufan-rock64#16 [ffffa2bfc9ec3df8] finish_task_switch at ffffffffa76e5d07
 ayufan-rock64#17 [ffffa2bfc9ec3e78] iscsit_take_action_for_connection_exit at ffffffffc0991c23 [iscsi_target_mod]
 ayufan-rock64#18 [ffffa2bfc9ec3ea0] iscsi_target_tx_thread at ffffffffc09a403b [iscsi_target_mod]
 ayufan-rock64#19 [ffffa2bfc9ec3f08] kthread at ffffffffa76d8080
 ayufan-rock64#20 [ffffa2bfc9ec3f50] ret_from_fork at ffffffffa8200364

Fixes: 36d4cb4 ("scsi: target: Avoid that EXTENDED COPY commands trigger lock inversion")
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Link: https://lore.kernel.org/r/20230918225848.66463-1-junxiao.bi@oracle.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
commit 5a22fbc upstream.

When LAN9303 is MDIO-connected two callchains exist into
mdio->bus->write():

1. switch ports 1&2 ("physical" PHYs):

virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})->
  lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested

2. LAN9303 virtual PHY:

virtual MDIO bus (lan9303_phy_{read|write}) ->
  lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write}

If the latter functions just take
mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP
false-positive splat. It's false-positive because the first
mdio_lock in the second callchain above belongs to virtual MDIO bus, the
second mdio_lock belongs to physical MDIO bus.

Consequent annotation in lan9303_mdio_{read|write} as nested lock
(similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus)
prevents the following splat:

WARNING: possible circular locking dependency detected
5.15.71 #1 Not tainted
------------------------------------------------------
kworker/u4:3/609 is trying to acquire lock:
ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex
but task is already holding lock:
ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&bus->mdio_lock){+.+.}-{3:3}:
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       lan9303_mdio_read
       _regmap_read
       regmap_read
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
-> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}:
       __lock_acquire
       lock_acquire.part.0
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       regmap_lock_mutex
       regmap_read
       lan9303_phy_read
       dsa_slave_phy_read
       __mdiobus_read
       mdiobus_read
       get_phy_device
       mdiobus_scan
       __mdiobus_register
       dsa_register_switch
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
other info that might help us debug this:
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&bus->mdio_lock);
                               lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
                               lock(&bus->mdio_lock);
  lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
*** DEADLOCK ***
5 locks held by kworker/u4:3/609:
 #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work
 #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work
 #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach
 #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch
 #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
stack backtrace:
CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1
Workqueue: events_unbound deferred_probe_work_func
Call trace:
 dump_backtrace
 show_stack
 dump_stack_lvl
 dump_stack
 print_circular_bug
 check_noncircular
 __lock_acquire
 lock_acquire.part.0
 lock_acquire
 __mutex_lock
 mutex_lock_nested
 regmap_lock_mutex
 regmap_read
 lan9303_phy_read
 dsa_slave_phy_read
 __mdiobus_read
 mdiobus_read
 get_phy_device
 mdiobus_scan
 __mdiobus_register
 dsa_register_switch
 lan9303_probe
 lan9303_mdio_probe
...

Cc: stable@vger.kernel.org
Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support")
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20231027065741.534971-1-alexander.sverdlin@siemens.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
commit 7fed14f upstream.

The following warning appears when using buffered events:

[  203.556451] WARNING: CPU: 53 PID: 10220 at kernel/trace/ring_buffer.c:3912 ring_buffer_discard_commit+0x2eb/0x420
[...]
[  203.670690] CPU: 53 PID: 10220 Comm: stress-ng-sysin Tainted: G            E      6.7.0-rc2-default #4 56e6d0fcf5581e6e51eaaecbdaec2a2338c80f3a
[  203.670704] Hardware name: Intel Corp. GROVEPORT/GROVEPORT, BIOS GVPRCRB1.86B.0016.D04.1705030402 05/03/2017
[  203.670709] RIP: 0010:ring_buffer_discard_commit+0x2eb/0x420
[  203.735721] Code: 4c 8b 4a 50 48 8b 42 48 49 39 c1 0f 84 b3 00 00 00 49 83 e8 01 75 b1 48 8b 42 10 f0 ff 40 08 0f 0b e9 fc fe ff ff f0 ff 47 08 <0f> 0b e9 77 fd ff ff 48 8b 42 10 f0 ff 40 08 0f 0b e9 f5 fe ff ff
[  203.735734] RSP: 0018:ffffb4ae4f7b7d80 EFLAGS: 00010202
[  203.735745] RAX: 0000000000000000 RBX: ffffb4ae4f7b7de0 RCX: ffff8ac10662c000
[  203.735754] RDX: ffff8ac0c750be00 RSI: ffff8ac10662c000 RDI: ffff8ac0c004d400
[  203.781832] RBP: ffff8ac0c039cea0 R08: 0000000000000000 R09: 0000000000000000
[  203.781839] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[  203.781842] R13: ffff8ac10662c000 R14: ffff8ac0c004d400 R15: ffff8ac10662c008
[  203.781846] FS:  00007f4cd8a67740(0000) GS:ffff8ad798880000(0000) knlGS:0000000000000000
[  203.781851] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  203.781855] CR2: 0000559766a74028 CR3: 00000001804c4000 CR4: 00000000001506f0
[  203.781862] Call Trace:
[  203.781870]  <TASK>
[  203.851949]  trace_event_buffer_commit+0x1ea/0x250
[  203.851967]  trace_event_raw_event_sys_enter+0x83/0xe0
[  203.851983]  syscall_trace_enter.isra.0+0x182/0x1a0
[  203.851990]  do_syscall_64+0x3a/0xe0
[  203.852075]  entry_SYSCALL_64_after_hwframe+0x6e/0x76
[  203.852090] RIP: 0033:0x7f4cd870fa77
[  203.982920] Code: 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 90 b8 89 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e9 43 0e 00 f7 d8 64 89 01 48
[  203.982932] RSP: 002b:00007fff99717dd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000089
[  203.982942] RAX: ffffffffffffffda RBX: 0000558ea1d7b6f0 RCX: 00007f4cd870fa77
[  203.982948] RDX: 0000000000000000 RSI: 00007fff99717de0 RDI: 0000558ea1d7b6f0
[  203.982957] RBP: 00007fff99717de0 R08: 00007fff997180e0 R09: 00007fff997180e0
[  203.982962] R10: 00007fff997180e0 R11: 0000000000000246 R12: 00007fff99717f40
[  204.049239] R13: 00007fff99718590 R14: 0000558e9f2127a8 R15: 00007fff997180b0
[  204.049256]  </TASK>

For instance, it can be triggered by running these two commands in
parallel:

 $ while true; do
    echo hist:key=id.syscall:val=hitcount > \
      /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger;
  done
 $ stress-ng --sysinfo $(nproc)

The warning indicates that the current ring_buffer_per_cpu is not in the
committing state. It happens because the active ring_buffer_event
doesn't actually come from the ring_buffer_per_cpu but is allocated from
trace_buffered_event.

The bug is in function trace_buffered_event_disable() where the
following normally happens:

* The code invokes disable_trace_buffered_event() via
  smp_call_function_many() and follows it by synchronize_rcu(). This
  increments the per-CPU variable trace_buffered_event_cnt on each
  target CPU and grants trace_buffered_event_disable() the exclusive
  access to the per-CPU variable trace_buffered_event.

* Maintenance is performed on trace_buffered_event, all per-CPU event
  buffers get freed.

* The code invokes enable_trace_buffered_event() via
  smp_call_function_many(). This decrements trace_buffered_event_cnt and
  releases the access to trace_buffered_event.

A problem is that smp_call_function_many() runs a given function on all
target CPUs except on the current one. The following can then occur:

* Task X executing trace_buffered_event_disable() runs on CPU 0.

* The control reaches synchronize_rcu() and the task gets rescheduled on
  another CPU 1.

* The RCU synchronization finishes. At this point,
  trace_buffered_event_disable() has the exclusive access to all
  trace_buffered_event variables except trace_buffered_event[CPU0]
  because trace_buffered_event_cnt[CPU0] is never incremented and if the
  buffer is currently unused, remains set to 0.

* A different task Y is scheduled on CPU 0 and hits a trace event. The
  code in trace_event_buffer_lock_reserve() sees that
  trace_buffered_event_cnt[CPU0] is set to 0 and decides the use the
  buffer provided by trace_buffered_event[CPU0].

* Task X continues its execution in trace_buffered_event_disable(). The
  code incorrectly frees the event buffer pointed by
  trace_buffered_event[CPU0] and resets the variable to NULL.

* Task Y writes event data to the now freed buffer and later detects the
  created inconsistency.

The issue is observable since commit dea4997 ("tracing: Fix warning
in trace_buffered_event_disable()") which moved the call of
trace_buffered_event_disable() in __ftrace_event_enable_disable()
earlier, prior to invoking call->class->reg(.. TRACE_REG_UNREGISTER ..).
The underlying problem in trace_buffered_event_disable() is however
present since the original implementation in commit 0fc1b09
("tracing: Use temp buffer when filtering events").

Fix the problem by replacing the two smp_call_function_many() calls with
on_each_cpu_mask() which invokes a given callback on all CPUs.

Link: https://lore.kernel.org/all/20231127151248.7232-2-petr.pavlu@suse.com/
Link: https://lkml.kernel.org/r/20231205161736.19663-2-petr.pavlu@suse.com

Cc: stable@vger.kernel.org
Fixes: 0fc1b09 ("tracing: Use temp buffer when filtering events")
Fixes: dea4997 ("tracing: Fix warning in trace_buffered_event_disable()")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
[ Upstream commit a154f5f ]

The following call trace shows a deadlock issue due to recursive locking of
mutex "device_mutex". First lock acquire is in target_for_each_device() and
second in target_free_device().

 PID: 148266   TASK: ffff8be21ffb5d00  CPU: 10   COMMAND: "iscsi_ttx"
  #0 [ffffa2bfc9ec3b18] __schedule at ffffffffa8060e7f
  #1 [ffffa2bfc9ec3ba0] schedule at ffffffffa8061224
  #2 [ffffa2bfc9ec3bb8] schedule_preempt_disabled at ffffffffa80615ee
  #3 [ffffa2bfc9ec3bc8] __mutex_lock at ffffffffa8062fd7
  #4 [ffffa2bfc9ec3c40] __mutex_lock_slowpath at ffffffffa80631d3
  #5 [ffffa2bfc9ec3c50] mutex_lock at ffffffffa806320c
  ayufan-rock64#6 [ffffa2bfc9ec3c68] target_free_device at ffffffffc0935998 [target_core_mod]
  ayufan-rock64#7 [ffffa2bfc9ec3c90] target_core_dev_release at ffffffffc092f975 [target_core_mod]
  ayufan-rock64#8 [ffffa2bfc9ec3ca0] config_item_put at ffffffffa79d250f
  ayufan-rock64#9 [ffffa2bfc9ec3cd0] config_item_put at ffffffffa79d2583
 ayufan-rock64#10 [ffffa2bfc9ec3ce0] target_devices_idr_iter at ffffffffc0933f3a [target_core_mod]
 ayufan-rock64#11 [ffffa2bfc9ec3d00] idr_for_each at ffffffffa803f6fc
 ayufan-rock64#12 [ffffa2bfc9ec3d60] target_for_each_device at ffffffffc0935670 [target_core_mod]
 ayufan-rock64#13 [ffffa2bfc9ec3d98] transport_deregister_session at ffffffffc0946408 [target_core_mod]
 ayufan-rock64#14 [ffffa2bfc9ec3dc8] iscsit_close_session at ffffffffc09a44a6 [iscsi_target_mod]
 ayufan-rock64#15 [ffffa2bfc9ec3df0] iscsit_close_connection at ffffffffc09a4a88 [iscsi_target_mod]
 ayufan-rock64#16 [ffffa2bfc9ec3df8] finish_task_switch at ffffffffa76e5d07
 ayufan-rock64#17 [ffffa2bfc9ec3e78] iscsit_take_action_for_connection_exit at ffffffffc0991c23 [iscsi_target_mod]
 ayufan-rock64#18 [ffffa2bfc9ec3ea0] iscsi_target_tx_thread at ffffffffc09a403b [iscsi_target_mod]
 ayufan-rock64#19 [ffffa2bfc9ec3f08] kthread at ffffffffa76d8080
 ayufan-rock64#20 [ffffa2bfc9ec3f50] ret_from_fork at ffffffffa8200364

Fixes: 36d4cb4 ("scsi: target: Avoid that EXTENDED COPY commands trigger lock inversion")
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Link: https://lore.kernel.org/r/20230918225848.66463-1-junxiao.bi@oracle.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
commit 5a22fbc upstream.

When LAN9303 is MDIO-connected two callchains exist into
mdio->bus->write():

1. switch ports 1&2 ("physical" PHYs):

virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})->
  lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested

2. LAN9303 virtual PHY:

virtual MDIO bus (lan9303_phy_{read|write}) ->
  lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write}

If the latter functions just take
mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP
false-positive splat. It's false-positive because the first
mdio_lock in the second callchain above belongs to virtual MDIO bus, the
second mdio_lock belongs to physical MDIO bus.

Consequent annotation in lan9303_mdio_{read|write} as nested lock
(similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus)
prevents the following splat:

WARNING: possible circular locking dependency detected
5.15.71 #1 Not tainted
------------------------------------------------------
kworker/u4:3/609 is trying to acquire lock:
ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex
but task is already holding lock:
ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&bus->mdio_lock){+.+.}-{3:3}:
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       lan9303_mdio_read
       _regmap_read
       regmap_read
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
-> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}:
       __lock_acquire
       lock_acquire.part.0
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       regmap_lock_mutex
       regmap_read
       lan9303_phy_read
       dsa_slave_phy_read
       __mdiobus_read
       mdiobus_read
       get_phy_device
       mdiobus_scan
       __mdiobus_register
       dsa_register_switch
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
other info that might help us debug this:
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&bus->mdio_lock);
                               lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
                               lock(&bus->mdio_lock);
  lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
*** DEADLOCK ***
5 locks held by kworker/u4:3/609:
 #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work
 #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work
 #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach
 #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch
 #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
stack backtrace:
CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1
Workqueue: events_unbound deferred_probe_work_func
Call trace:
 dump_backtrace
 show_stack
 dump_stack_lvl
 dump_stack
 print_circular_bug
 check_noncircular
 __lock_acquire
 lock_acquire.part.0
 lock_acquire
 __mutex_lock
 mutex_lock_nested
 regmap_lock_mutex
 regmap_read
 lan9303_phy_read
 dsa_slave_phy_read
 __mdiobus_read
 mdiobus_read
 get_phy_device
 mdiobus_scan
 __mdiobus_register
 dsa_register_switch
 lan9303_probe
 lan9303_mdio_probe
...

Cc: stable@vger.kernel.org
Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support")
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20231027065741.534971-1-alexander.sverdlin@siemens.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
commit 7fed14f upstream.

The following warning appears when using buffered events:

[  203.556451] WARNING: CPU: 53 PID: 10220 at kernel/trace/ring_buffer.c:3912 ring_buffer_discard_commit+0x2eb/0x420
[...]
[  203.670690] CPU: 53 PID: 10220 Comm: stress-ng-sysin Tainted: G            E      6.7.0-rc2-default #4 56e6d0fcf5581e6e51eaaecbdaec2a2338c80f3a
[  203.670704] Hardware name: Intel Corp. GROVEPORT/GROVEPORT, BIOS GVPRCRB1.86B.0016.D04.1705030402 05/03/2017
[  203.670709] RIP: 0010:ring_buffer_discard_commit+0x2eb/0x420
[  203.735721] Code: 4c 8b 4a 50 48 8b 42 48 49 39 c1 0f 84 b3 00 00 00 49 83 e8 01 75 b1 48 8b 42 10 f0 ff 40 08 0f 0b e9 fc fe ff ff f0 ff 47 08 <0f> 0b e9 77 fd ff ff 48 8b 42 10 f0 ff 40 08 0f 0b e9 f5 fe ff ff
[  203.735734] RSP: 0018:ffffb4ae4f7b7d80 EFLAGS: 00010202
[  203.735745] RAX: 0000000000000000 RBX: ffffb4ae4f7b7de0 RCX: ffff8ac10662c000
[  203.735754] RDX: ffff8ac0c750be00 RSI: ffff8ac10662c000 RDI: ffff8ac0c004d400
[  203.781832] RBP: ffff8ac0c039cea0 R08: 0000000000000000 R09: 0000000000000000
[  203.781839] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[  203.781842] R13: ffff8ac10662c000 R14: ffff8ac0c004d400 R15: ffff8ac10662c008
[  203.781846] FS:  00007f4cd8a67740(0000) GS:ffff8ad798880000(0000) knlGS:0000000000000000
[  203.781851] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  203.781855] CR2: 0000559766a74028 CR3: 00000001804c4000 CR4: 00000000001506f0
[  203.781862] Call Trace:
[  203.781870]  <TASK>
[  203.851949]  trace_event_buffer_commit+0x1ea/0x250
[  203.851967]  trace_event_raw_event_sys_enter+0x83/0xe0
[  203.851983]  syscall_trace_enter.isra.0+0x182/0x1a0
[  203.851990]  do_syscall_64+0x3a/0xe0
[  203.852075]  entry_SYSCALL_64_after_hwframe+0x6e/0x76
[  203.852090] RIP: 0033:0x7f4cd870fa77
[  203.982920] Code: 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 90 b8 89 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e9 43 0e 00 f7 d8 64 89 01 48
[  203.982932] RSP: 002b:00007fff99717dd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000089
[  203.982942] RAX: ffffffffffffffda RBX: 0000558ea1d7b6f0 RCX: 00007f4cd870fa77
[  203.982948] RDX: 0000000000000000 RSI: 00007fff99717de0 RDI: 0000558ea1d7b6f0
[  203.982957] RBP: 00007fff99717de0 R08: 00007fff997180e0 R09: 00007fff997180e0
[  203.982962] R10: 00007fff997180e0 R11: 0000000000000246 R12: 00007fff99717f40
[  204.049239] R13: 00007fff99718590 R14: 0000558e9f2127a8 R15: 00007fff997180b0
[  204.049256]  </TASK>

For instance, it can be triggered by running these two commands in
parallel:

 $ while true; do
    echo hist:key=id.syscall:val=hitcount > \
      /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger;
  done
 $ stress-ng --sysinfo $(nproc)

The warning indicates that the current ring_buffer_per_cpu is not in the
committing state. It happens because the active ring_buffer_event
doesn't actually come from the ring_buffer_per_cpu but is allocated from
trace_buffered_event.

The bug is in function trace_buffered_event_disable() where the
following normally happens:

* The code invokes disable_trace_buffered_event() via
  smp_call_function_many() and follows it by synchronize_rcu(). This
  increments the per-CPU variable trace_buffered_event_cnt on each
  target CPU and grants trace_buffered_event_disable() the exclusive
  access to the per-CPU variable trace_buffered_event.

* Maintenance is performed on trace_buffered_event, all per-CPU event
  buffers get freed.

* The code invokes enable_trace_buffered_event() via
  smp_call_function_many(). This decrements trace_buffered_event_cnt and
  releases the access to trace_buffered_event.

A problem is that smp_call_function_many() runs a given function on all
target CPUs except on the current one. The following can then occur:

* Task X executing trace_buffered_event_disable() runs on CPU 0.

* The control reaches synchronize_rcu() and the task gets rescheduled on
  another CPU 1.

* The RCU synchronization finishes. At this point,
  trace_buffered_event_disable() has the exclusive access to all
  trace_buffered_event variables except trace_buffered_event[CPU0]
  because trace_buffered_event_cnt[CPU0] is never incremented and if the
  buffer is currently unused, remains set to 0.

* A different task Y is scheduled on CPU 0 and hits a trace event. The
  code in trace_event_buffer_lock_reserve() sees that
  trace_buffered_event_cnt[CPU0] is set to 0 and decides the use the
  buffer provided by trace_buffered_event[CPU0].

* Task X continues its execution in trace_buffered_event_disable(). The
  code incorrectly frees the event buffer pointed by
  trace_buffered_event[CPU0] and resets the variable to NULL.

* Task Y writes event data to the now freed buffer and later detects the
  created inconsistency.

The issue is observable since commit dea4997 ("tracing: Fix warning
in trace_buffered_event_disable()") which moved the call of
trace_buffered_event_disable() in __ftrace_event_enable_disable()
earlier, prior to invoking call->class->reg(.. TRACE_REG_UNREGISTER ..).
The underlying problem in trace_buffered_event_disable() is however
present since the original implementation in commit 0fc1b09
("tracing: Use temp buffer when filtering events").

Fix the problem by replacing the two smp_call_function_many() calls with
on_each_cpu_mask() which invokes a given callback on all CPUs.

Link: https://lore.kernel.org/all/20231127151248.7232-2-petr.pavlu@suse.com/
Link: https://lkml.kernel.org/r/20231205161736.19663-2-petr.pavlu@suse.com

Cc: stable@vger.kernel.org
Fixes: 0fc1b09 ("tracing: Use temp buffer when filtering events")
Fixes: dea4997 ("tracing: Fix warning in trace_buffered_event_disable()")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
[ Upstream commit a154f5f ]

The following call trace shows a deadlock issue due to recursive locking of
mutex "device_mutex". First lock acquire is in target_for_each_device() and
second in target_free_device().

 PID: 148266   TASK: ffff8be21ffb5d00  CPU: 10   COMMAND: "iscsi_ttx"
  #0 [ffffa2bfc9ec3b18] __schedule at ffffffffa8060e7f
  #1 [ffffa2bfc9ec3ba0] schedule at ffffffffa8061224
  #2 [ffffa2bfc9ec3bb8] schedule_preempt_disabled at ffffffffa80615ee
  #3 [ffffa2bfc9ec3bc8] __mutex_lock at ffffffffa8062fd7
  #4 [ffffa2bfc9ec3c40] __mutex_lock_slowpath at ffffffffa80631d3
  #5 [ffffa2bfc9ec3c50] mutex_lock at ffffffffa806320c
  ayufan-rock64#6 [ffffa2bfc9ec3c68] target_free_device at ffffffffc0935998 [target_core_mod]
  ayufan-rock64#7 [ffffa2bfc9ec3c90] target_core_dev_release at ffffffffc092f975 [target_core_mod]
  ayufan-rock64#8 [ffffa2bfc9ec3ca0] config_item_put at ffffffffa79d250f
  ayufan-rock64#9 [ffffa2bfc9ec3cd0] config_item_put at ffffffffa79d2583
 ayufan-rock64#10 [ffffa2bfc9ec3ce0] target_devices_idr_iter at ffffffffc0933f3a [target_core_mod]
 ayufan-rock64#11 [ffffa2bfc9ec3d00] idr_for_each at ffffffffa803f6fc
 ayufan-rock64#12 [ffffa2bfc9ec3d60] target_for_each_device at ffffffffc0935670 [target_core_mod]
 ayufan-rock64#13 [ffffa2bfc9ec3d98] transport_deregister_session at ffffffffc0946408 [target_core_mod]
 ayufan-rock64#14 [ffffa2bfc9ec3dc8] iscsit_close_session at ffffffffc09a44a6 [iscsi_target_mod]
 ayufan-rock64#15 [ffffa2bfc9ec3df0] iscsit_close_connection at ffffffffc09a4a88 [iscsi_target_mod]
 ayufan-rock64#16 [ffffa2bfc9ec3df8] finish_task_switch at ffffffffa76e5d07
 ayufan-rock64#17 [ffffa2bfc9ec3e78] iscsit_take_action_for_connection_exit at ffffffffc0991c23 [iscsi_target_mod]
 ayufan-rock64#18 [ffffa2bfc9ec3ea0] iscsi_target_tx_thread at ffffffffc09a403b [iscsi_target_mod]
 ayufan-rock64#19 [ffffa2bfc9ec3f08] kthread at ffffffffa76d8080
 ayufan-rock64#20 [ffffa2bfc9ec3f50] ret_from_fork at ffffffffa8200364

Fixes: 36d4cb4 ("scsi: target: Avoid that EXTENDED COPY commands trigger lock inversion")
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Link: https://lore.kernel.org/r/20230918225848.66463-1-junxiao.bi@oracle.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
commit 5a22fbc upstream.

When LAN9303 is MDIO-connected two callchains exist into
mdio->bus->write():

1. switch ports 1&2 ("physical" PHYs):

virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})->
  lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested

2. LAN9303 virtual PHY:

virtual MDIO bus (lan9303_phy_{read|write}) ->
  lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write}

If the latter functions just take
mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP
false-positive splat. It's false-positive because the first
mdio_lock in the second callchain above belongs to virtual MDIO bus, the
second mdio_lock belongs to physical MDIO bus.

Consequent annotation in lan9303_mdio_{read|write} as nested lock
(similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus)
prevents the following splat:

WARNING: possible circular locking dependency detected
5.15.71 #1 Not tainted
------------------------------------------------------
kworker/u4:3/609 is trying to acquire lock:
ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex
but task is already holding lock:
ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&bus->mdio_lock){+.+.}-{3:3}:
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       lan9303_mdio_read
       _regmap_read
       regmap_read
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
-> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}:
       __lock_acquire
       lock_acquire.part.0
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       regmap_lock_mutex
       regmap_read
       lan9303_phy_read
       dsa_slave_phy_read
       __mdiobus_read
       mdiobus_read
       get_phy_device
       mdiobus_scan
       __mdiobus_register
       dsa_register_switch
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
other info that might help us debug this:
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&bus->mdio_lock);
                               lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
                               lock(&bus->mdio_lock);
  lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
*** DEADLOCK ***
5 locks held by kworker/u4:3/609:
 #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work
 #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work
 #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach
 #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch
 #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
stack backtrace:
CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1
Workqueue: events_unbound deferred_probe_work_func
Call trace:
 dump_backtrace
 show_stack
 dump_stack_lvl
 dump_stack
 print_circular_bug
 check_noncircular
 __lock_acquire
 lock_acquire.part.0
 lock_acquire
 __mutex_lock
 mutex_lock_nested
 regmap_lock_mutex
 regmap_read
 lan9303_phy_read
 dsa_slave_phy_read
 __mdiobus_read
 mdiobus_read
 get_phy_device
 mdiobus_scan
 __mdiobus_register
 dsa_register_switch
 lan9303_probe
 lan9303_mdio_probe
...

Cc: stable@vger.kernel.org
Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support")
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20231027065741.534971-1-alexander.sverdlin@siemens.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
commit 7fed14f upstream.

The following warning appears when using buffered events:

[  203.556451] WARNING: CPU: 53 PID: 10220 at kernel/trace/ring_buffer.c:3912 ring_buffer_discard_commit+0x2eb/0x420
[...]
[  203.670690] CPU: 53 PID: 10220 Comm: stress-ng-sysin Tainted: G            E      6.7.0-rc2-default #4 56e6d0fcf5581e6e51eaaecbdaec2a2338c80f3a
[  203.670704] Hardware name: Intel Corp. GROVEPORT/GROVEPORT, BIOS GVPRCRB1.86B.0016.D04.1705030402 05/03/2017
[  203.670709] RIP: 0010:ring_buffer_discard_commit+0x2eb/0x420
[  203.735721] Code: 4c 8b 4a 50 48 8b 42 48 49 39 c1 0f 84 b3 00 00 00 49 83 e8 01 75 b1 48 8b 42 10 f0 ff 40 08 0f 0b e9 fc fe ff ff f0 ff 47 08 <0f> 0b e9 77 fd ff ff 48 8b 42 10 f0 ff 40 08 0f 0b e9 f5 fe ff ff
[  203.735734] RSP: 0018:ffffb4ae4f7b7d80 EFLAGS: 00010202
[  203.735745] RAX: 0000000000000000 RBX: ffffb4ae4f7b7de0 RCX: ffff8ac10662c000
[  203.735754] RDX: ffff8ac0c750be00 RSI: ffff8ac10662c000 RDI: ffff8ac0c004d400
[  203.781832] RBP: ffff8ac0c039cea0 R08: 0000000000000000 R09: 0000000000000000
[  203.781839] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[  203.781842] R13: ffff8ac10662c000 R14: ffff8ac0c004d400 R15: ffff8ac10662c008
[  203.781846] FS:  00007f4cd8a67740(0000) GS:ffff8ad798880000(0000) knlGS:0000000000000000
[  203.781851] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  203.781855] CR2: 0000559766a74028 CR3: 00000001804c4000 CR4: 00000000001506f0
[  203.781862] Call Trace:
[  203.781870]  <TASK>
[  203.851949]  trace_event_buffer_commit+0x1ea/0x250
[  203.851967]  trace_event_raw_event_sys_enter+0x83/0xe0
[  203.851983]  syscall_trace_enter.isra.0+0x182/0x1a0
[  203.851990]  do_syscall_64+0x3a/0xe0
[  203.852075]  entry_SYSCALL_64_after_hwframe+0x6e/0x76
[  203.852090] RIP: 0033:0x7f4cd870fa77
[  203.982920] Code: 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 90 b8 89 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e9 43 0e 00 f7 d8 64 89 01 48
[  203.982932] RSP: 002b:00007fff99717dd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000089
[  203.982942] RAX: ffffffffffffffda RBX: 0000558ea1d7b6f0 RCX: 00007f4cd870fa77
[  203.982948] RDX: 0000000000000000 RSI: 00007fff99717de0 RDI: 0000558ea1d7b6f0
[  203.982957] RBP: 00007fff99717de0 R08: 00007fff997180e0 R09: 00007fff997180e0
[  203.982962] R10: 00007fff997180e0 R11: 0000000000000246 R12: 00007fff99717f40
[  204.049239] R13: 00007fff99718590 R14: 0000558e9f2127a8 R15: 00007fff997180b0
[  204.049256]  </TASK>

For instance, it can be triggered by running these two commands in
parallel:

 $ while true; do
    echo hist:key=id.syscall:val=hitcount > \
      /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger;
  done
 $ stress-ng --sysinfo $(nproc)

The warning indicates that the current ring_buffer_per_cpu is not in the
committing state. It happens because the active ring_buffer_event
doesn't actually come from the ring_buffer_per_cpu but is allocated from
trace_buffered_event.

The bug is in function trace_buffered_event_disable() where the
following normally happens:

* The code invokes disable_trace_buffered_event() via
  smp_call_function_many() and follows it by synchronize_rcu(). This
  increments the per-CPU variable trace_buffered_event_cnt on each
  target CPU and grants trace_buffered_event_disable() the exclusive
  access to the per-CPU variable trace_buffered_event.

* Maintenance is performed on trace_buffered_event, all per-CPU event
  buffers get freed.

* The code invokes enable_trace_buffered_event() via
  smp_call_function_many(). This decrements trace_buffered_event_cnt and
  releases the access to trace_buffered_event.

A problem is that smp_call_function_many() runs a given function on all
target CPUs except on the current one. The following can then occur:

* Task X executing trace_buffered_event_disable() runs on CPU 0.

* The control reaches synchronize_rcu() and the task gets rescheduled on
  another CPU 1.

* The RCU synchronization finishes. At this point,
  trace_buffered_event_disable() has the exclusive access to all
  trace_buffered_event variables except trace_buffered_event[CPU0]
  because trace_buffered_event_cnt[CPU0] is never incremented and if the
  buffer is currently unused, remains set to 0.

* A different task Y is scheduled on CPU 0 and hits a trace event. The
  code in trace_event_buffer_lock_reserve() sees that
  trace_buffered_event_cnt[CPU0] is set to 0 and decides the use the
  buffer provided by trace_buffered_event[CPU0].

* Task X continues its execution in trace_buffered_event_disable(). The
  code incorrectly frees the event buffer pointed by
  trace_buffered_event[CPU0] and resets the variable to NULL.

* Task Y writes event data to the now freed buffer and later detects the
  created inconsistency.

The issue is observable since commit dea4997 ("tracing: Fix warning
in trace_buffered_event_disable()") which moved the call of
trace_buffered_event_disable() in __ftrace_event_enable_disable()
earlier, prior to invoking call->class->reg(.. TRACE_REG_UNREGISTER ..).
The underlying problem in trace_buffered_event_disable() is however
present since the original implementation in commit 0fc1b09
("tracing: Use temp buffer when filtering events").

Fix the problem by replacing the two smp_call_function_many() calls with
on_each_cpu_mask() which invokes a given callback on all CPUs.

Link: https://lore.kernel.org/all/20231127151248.7232-2-petr.pavlu@suse.com/
Link: https://lkml.kernel.org/r/20231205161736.19663-2-petr.pavlu@suse.com

Cc: stable@vger.kernel.org
Fixes: 0fc1b09 ("tracing: Use temp buffer when filtering events")
Fixes: dea4997 ("tracing: Fix warning in trace_buffered_event_disable()")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
[ Upstream commit a154f5f ]

The following call trace shows a deadlock issue due to recursive locking of
mutex "device_mutex". First lock acquire is in target_for_each_device() and
second in target_free_device().

 PID: 148266   TASK: ffff8be21ffb5d00  CPU: 10   COMMAND: "iscsi_ttx"
  #0 [ffffa2bfc9ec3b18] __schedule at ffffffffa8060e7f
  #1 [ffffa2bfc9ec3ba0] schedule at ffffffffa8061224
  #2 [ffffa2bfc9ec3bb8] schedule_preempt_disabled at ffffffffa80615ee
  #3 [ffffa2bfc9ec3bc8] __mutex_lock at ffffffffa8062fd7
  #4 [ffffa2bfc9ec3c40] __mutex_lock_slowpath at ffffffffa80631d3
  #5 [ffffa2bfc9ec3c50] mutex_lock at ffffffffa806320c
  ayufan-rock64#6 [ffffa2bfc9ec3c68] target_free_device at ffffffffc0935998 [target_core_mod]
  ayufan-rock64#7 [ffffa2bfc9ec3c90] target_core_dev_release at ffffffffc092f975 [target_core_mod]
  ayufan-rock64#8 [ffffa2bfc9ec3ca0] config_item_put at ffffffffa79d250f
  ayufan-rock64#9 [ffffa2bfc9ec3cd0] config_item_put at ffffffffa79d2583
 ayufan-rock64#10 [ffffa2bfc9ec3ce0] target_devices_idr_iter at ffffffffc0933f3a [target_core_mod]
 ayufan-rock64#11 [ffffa2bfc9ec3d00] idr_for_each at ffffffffa803f6fc
 ayufan-rock64#12 [ffffa2bfc9ec3d60] target_for_each_device at ffffffffc0935670 [target_core_mod]
 ayufan-rock64#13 [ffffa2bfc9ec3d98] transport_deregister_session at ffffffffc0946408 [target_core_mod]
 ayufan-rock64#14 [ffffa2bfc9ec3dc8] iscsit_close_session at ffffffffc09a44a6 [iscsi_target_mod]
 ayufan-rock64#15 [ffffa2bfc9ec3df0] iscsit_close_connection at ffffffffc09a4a88 [iscsi_target_mod]
 ayufan-rock64#16 [ffffa2bfc9ec3df8] finish_task_switch at ffffffffa76e5d07
 ayufan-rock64#17 [ffffa2bfc9ec3e78] iscsit_take_action_for_connection_exit at ffffffffc0991c23 [iscsi_target_mod]
 ayufan-rock64#18 [ffffa2bfc9ec3ea0] iscsi_target_tx_thread at ffffffffc09a403b [iscsi_target_mod]
 ayufan-rock64#19 [ffffa2bfc9ec3f08] kthread at ffffffffa76d8080
 ayufan-rock64#20 [ffffa2bfc9ec3f50] ret_from_fork at ffffffffa8200364

Fixes: 36d4cb4 ("scsi: target: Avoid that EXTENDED COPY commands trigger lock inversion")
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Link: https://lore.kernel.org/r/20230918225848.66463-1-junxiao.bi@oracle.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
commit 5a22fbc upstream.

When LAN9303 is MDIO-connected two callchains exist into
mdio->bus->write():

1. switch ports 1&2 ("physical" PHYs):

virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})->
  lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested

2. LAN9303 virtual PHY:

virtual MDIO bus (lan9303_phy_{read|write}) ->
  lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write}

If the latter functions just take
mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP
false-positive splat. It's false-positive because the first
mdio_lock in the second callchain above belongs to virtual MDIO bus, the
second mdio_lock belongs to physical MDIO bus.

Consequent annotation in lan9303_mdio_{read|write} as nested lock
(similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus)
prevents the following splat:

WARNING: possible circular locking dependency detected
5.15.71 #1 Not tainted
------------------------------------------------------
kworker/u4:3/609 is trying to acquire lock:
ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex
but task is already holding lock:
ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&bus->mdio_lock){+.+.}-{3:3}:
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       lan9303_mdio_read
       _regmap_read
       regmap_read
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
-> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}:
       __lock_acquire
       lock_acquire.part.0
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       regmap_lock_mutex
       regmap_read
       lan9303_phy_read
       dsa_slave_phy_read
       __mdiobus_read
       mdiobus_read
       get_phy_device
       mdiobus_scan
       __mdiobus_register
       dsa_register_switch
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
other info that might help us debug this:
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&bus->mdio_lock);
                               lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
                               lock(&bus->mdio_lock);
  lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
*** DEADLOCK ***
5 locks held by kworker/u4:3/609:
 #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work
 #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work
 #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach
 #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch
 #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
stack backtrace:
CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1
Workqueue: events_unbound deferred_probe_work_func
Call trace:
 dump_backtrace
 show_stack
 dump_stack_lvl
 dump_stack
 print_circular_bug
 check_noncircular
 __lock_acquire
 lock_acquire.part.0
 lock_acquire
 __mutex_lock
 mutex_lock_nested
 regmap_lock_mutex
 regmap_read
 lan9303_phy_read
 dsa_slave_phy_read
 __mdiobus_read
 mdiobus_read
 get_phy_device
 mdiobus_scan
 __mdiobus_register
 dsa_register_switch
 lan9303_probe
 lan9303_mdio_probe
...

Cc: stable@vger.kernel.org
Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support")
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20231027065741.534971-1-alexander.sverdlin@siemens.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
commit 7fed14f upstream.

The following warning appears when using buffered events:

[  203.556451] WARNING: CPU: 53 PID: 10220 at kernel/trace/ring_buffer.c:3912 ring_buffer_discard_commit+0x2eb/0x420
[...]
[  203.670690] CPU: 53 PID: 10220 Comm: stress-ng-sysin Tainted: G            E      6.7.0-rc2-default #4 56e6d0fcf5581e6e51eaaecbdaec2a2338c80f3a
[  203.670704] Hardware name: Intel Corp. GROVEPORT/GROVEPORT, BIOS GVPRCRB1.86B.0016.D04.1705030402 05/03/2017
[  203.670709] RIP: 0010:ring_buffer_discard_commit+0x2eb/0x420
[  203.735721] Code: 4c 8b 4a 50 48 8b 42 48 49 39 c1 0f 84 b3 00 00 00 49 83 e8 01 75 b1 48 8b 42 10 f0 ff 40 08 0f 0b e9 fc fe ff ff f0 ff 47 08 <0f> 0b e9 77 fd ff ff 48 8b 42 10 f0 ff 40 08 0f 0b e9 f5 fe ff ff
[  203.735734] RSP: 0018:ffffb4ae4f7b7d80 EFLAGS: 00010202
[  203.735745] RAX: 0000000000000000 RBX: ffffb4ae4f7b7de0 RCX: ffff8ac10662c000
[  203.735754] RDX: ffff8ac0c750be00 RSI: ffff8ac10662c000 RDI: ffff8ac0c004d400
[  203.781832] RBP: ffff8ac0c039cea0 R08: 0000000000000000 R09: 0000000000000000
[  203.781839] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[  203.781842] R13: ffff8ac10662c000 R14: ffff8ac0c004d400 R15: ffff8ac10662c008
[  203.781846] FS:  00007f4cd8a67740(0000) GS:ffff8ad798880000(0000) knlGS:0000000000000000
[  203.781851] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  203.781855] CR2: 0000559766a74028 CR3: 00000001804c4000 CR4: 00000000001506f0
[  203.781862] Call Trace:
[  203.781870]  <TASK>
[  203.851949]  trace_event_buffer_commit+0x1ea/0x250
[  203.851967]  trace_event_raw_event_sys_enter+0x83/0xe0
[  203.851983]  syscall_trace_enter.isra.0+0x182/0x1a0
[  203.851990]  do_syscall_64+0x3a/0xe0
[  203.852075]  entry_SYSCALL_64_after_hwframe+0x6e/0x76
[  203.852090] RIP: 0033:0x7f4cd870fa77
[  203.982920] Code: 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 90 b8 89 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e9 43 0e 00 f7 d8 64 89 01 48
[  203.982932] RSP: 002b:00007fff99717dd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000089
[  203.982942] RAX: ffffffffffffffda RBX: 0000558ea1d7b6f0 RCX: 00007f4cd870fa77
[  203.982948] RDX: 0000000000000000 RSI: 00007fff99717de0 RDI: 0000558ea1d7b6f0
[  203.982957] RBP: 00007fff99717de0 R08: 00007fff997180e0 R09: 00007fff997180e0
[  203.982962] R10: 00007fff997180e0 R11: 0000000000000246 R12: 00007fff99717f40
[  204.049239] R13: 00007fff99718590 R14: 0000558e9f2127a8 R15: 00007fff997180b0
[  204.049256]  </TASK>

For instance, it can be triggered by running these two commands in
parallel:

 $ while true; do
    echo hist:key=id.syscall:val=hitcount > \
      /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger;
  done
 $ stress-ng --sysinfo $(nproc)

The warning indicates that the current ring_buffer_per_cpu is not in the
committing state. It happens because the active ring_buffer_event
doesn't actually come from the ring_buffer_per_cpu but is allocated from
trace_buffered_event.

The bug is in function trace_buffered_event_disable() where the
following normally happens:

* The code invokes disable_trace_buffered_event() via
  smp_call_function_many() and follows it by synchronize_rcu(). This
  increments the per-CPU variable trace_buffered_event_cnt on each
  target CPU and grants trace_buffered_event_disable() the exclusive
  access to the per-CPU variable trace_buffered_event.

* Maintenance is performed on trace_buffered_event, all per-CPU event
  buffers get freed.

* The code invokes enable_trace_buffered_event() via
  smp_call_function_many(). This decrements trace_buffered_event_cnt and
  releases the access to trace_buffered_event.

A problem is that smp_call_function_many() runs a given function on all
target CPUs except on the current one. The following can then occur:

* Task X executing trace_buffered_event_disable() runs on CPU 0.

* The control reaches synchronize_rcu() and the task gets rescheduled on
  another CPU 1.

* The RCU synchronization finishes. At this point,
  trace_buffered_event_disable() has the exclusive access to all
  trace_buffered_event variables except trace_buffered_event[CPU0]
  because trace_buffered_event_cnt[CPU0] is never incremented and if the
  buffer is currently unused, remains set to 0.

* A different task Y is scheduled on CPU 0 and hits a trace event. The
  code in trace_event_buffer_lock_reserve() sees that
  trace_buffered_event_cnt[CPU0] is set to 0 and decides the use the
  buffer provided by trace_buffered_event[CPU0].

* Task X continues its execution in trace_buffered_event_disable(). The
  code incorrectly frees the event buffer pointed by
  trace_buffered_event[CPU0] and resets the variable to NULL.

* Task Y writes event data to the now freed buffer and later detects the
  created inconsistency.

The issue is observable since commit dea4997 ("tracing: Fix warning
in trace_buffered_event_disable()") which moved the call of
trace_buffered_event_disable() in __ftrace_event_enable_disable()
earlier, prior to invoking call->class->reg(.. TRACE_REG_UNREGISTER ..).
The underlying problem in trace_buffered_event_disable() is however
present since the original implementation in commit 0fc1b09
("tracing: Use temp buffer when filtering events").

Fix the problem by replacing the two smp_call_function_many() calls with
on_each_cpu_mask() which invokes a given callback on all CPUs.

Link: https://lore.kernel.org/all/20231127151248.7232-2-petr.pavlu@suse.com/
Link: https://lkml.kernel.org/r/20231205161736.19663-2-petr.pavlu@suse.com

Cc: stable@vger.kernel.org
Fixes: 0fc1b09 ("tracing: Use temp buffer when filtering events")
Fixes: dea4997 ("tracing: Fix warning in trace_buffered_event_disable()")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
commit 5a22fbc upstream.

When LAN9303 is MDIO-connected two callchains exist into
mdio->bus->write():

1. switch ports 1&2 ("physical" PHYs):

virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})->
  lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested

2. LAN9303 virtual PHY:

virtual MDIO bus (lan9303_phy_{read|write}) ->
  lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write}

If the latter functions just take
mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP
false-positive splat. It's false-positive because the first
mdio_lock in the second callchain above belongs to virtual MDIO bus, the
second mdio_lock belongs to physical MDIO bus.

Consequent annotation in lan9303_mdio_{read|write} as nested lock
(similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus)
prevents the following splat:

WARNING: possible circular locking dependency detected
5.15.71 #1 Not tainted
------------------------------------------------------
kworker/u4:3/609 is trying to acquire lock:
ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex
but task is already holding lock:
ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&bus->mdio_lock){+.+.}-{3:3}:
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       lan9303_mdio_read
       _regmap_read
       regmap_read
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
-> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}:
       __lock_acquire
       lock_acquire.part.0
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       regmap_lock_mutex
       regmap_read
       lan9303_phy_read
       dsa_slave_phy_read
       __mdiobus_read
       mdiobus_read
       get_phy_device
       mdiobus_scan
       __mdiobus_register
       dsa_register_switch
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
other info that might help us debug this:
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&bus->mdio_lock);
                               lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
                               lock(&bus->mdio_lock);
  lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
*** DEADLOCK ***
5 locks held by kworker/u4:3/609:
 #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work
 #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work
 #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach
 #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch
 #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
stack backtrace:
CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1
Workqueue: events_unbound deferred_probe_work_func
Call trace:
 dump_backtrace
 show_stack
 dump_stack_lvl
 dump_stack
 print_circular_bug
 check_noncircular
 __lock_acquire
 lock_acquire.part.0
 lock_acquire
 __mutex_lock
 mutex_lock_nested
 regmap_lock_mutex
 regmap_read
 lan9303_phy_read
 dsa_slave_phy_read
 __mdiobus_read
 mdiobus_read
 get_phy_device
 mdiobus_scan
 __mdiobus_register
 dsa_register_switch
 lan9303_probe
 lan9303_mdio_probe
...

Cc: stable@vger.kernel.org
Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support")
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20231027065741.534971-1-alexander.sverdlin@siemens.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
[ Upstream commit e3e82fc ]

When creating ceq_0 during probing irdma, cqp.sc_cqp will be sent as a
cqp_request to cqp->sc_cqp.sq_ring. If the request is pending when
removing the irdma driver or unplugging its aux device, cqp.sc_cqp will be
dereferenced as wrong struct in irdma_free_pending_cqp_request().

  PID: 3669   TASK: ffff88aef892c000  CPU: 28  COMMAND: "kworker/28:0"
   #0 [fffffe0000549e38] crash_nmi_callback at ffffffff810e3a34
   #1 [fffffe0000549e40] nmi_handle at ffffffff810788b2
   #2 [fffffe0000549ea0] default_do_nmi at ffffffff8107938f
   #3 [fffffe0000549eb8] do_nmi at ffffffff81079582
   #4 [fffffe0000549ef0] end_repeat_nmi at ffffffff82e016b4
      [exception RIP: native_queued_spin_lock_slowpath+1291]
      RIP: ffffffff8127e72b  RSP: ffff88aa841ef778  RFLAGS: 00000046
      RAX: 0000000000000000  RBX: ffff88b01f849700  RCX: ffffffff8127e47e
      RDX: 0000000000000000  RSI: 0000000000000004  RDI: ffffffff83857ec0
      RBP: ffff88afe3e4efc8   R8: ffffed15fc7c9dfa   R9: ffffed15fc7c9dfa
      R10: 0000000000000001  R11: ffffed15fc7c9df9  R12: 0000000000740000
      R13: ffff88b01f849708  R14: 0000000000000003  R15: ffffed1603f092e1
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0000
  -- <NMI exception stack> --
   #5 [ffff88aa841ef778] native_queued_spin_lock_slowpath at ffffffff8127e72b
   ayufan-rock64#6 [ffff88aa841ef7b0] _raw_spin_lock_irqsave at ffffffff82c22aa4
   ayufan-rock64#7 [ffff88aa841ef7c8] __wake_up_common_lock at ffffffff81257363
   ayufan-rock64#8 [ffff88aa841ef888] irdma_free_pending_cqp_request at ffffffffa0ba12cc [irdma]
   ayufan-rock64#9 [ffff88aa841ef958] irdma_cleanup_pending_cqp_op at ffffffffa0ba1469 [irdma]
   ayufan-rock64#10 [ffff88aa841ef9c0] irdma_ctrl_deinit_hw at ffffffffa0b2989f [irdma]
   ayufan-rock64#11 [ffff88aa841efa28] irdma_remove at ffffffffa0b252df [irdma]
   ayufan-rock64#12 [ffff88aa841efae8] auxiliary_bus_remove at ffffffff8219afdb
   ayufan-rock64#13 [ffff88aa841efb00] device_release_driver_internal at ffffffff821882e6
   ayufan-rock64#14 [ffff88aa841efb38] bus_remove_device at ffffffff82184278
   ayufan-rock64#15 [ffff88aa841efb88] device_del at ffffffff82179d23
   ayufan-rock64#16 [ffff88aa841efc48] ice_unplug_aux_dev at ffffffffa0eb1c14 [ice]
   ayufan-rock64#17 [ffff88aa841efc68] ice_service_task at ffffffffa0d88201 [ice]
   ayufan-rock64#18 [ffff88aa841efde8] process_one_work at ffffffff811c589a
   ayufan-rock64#19 [ffff88aa841efe60] worker_thread at ffffffff811c71ff
   ayufan-rock64#20 [ffff88aa841eff10] kthread at ffffffff811d87a0
   ayufan-rock64#21 [ffff88aa841eff50] ret_from_fork at ffffffff82e0022f

Fixes: 44d9e52 ("RDMA/irdma: Implement device initialization definitions")
Link: https://lore.kernel.org/r/20231130081415.891006-1-lishifeng@sangfor.com.cn
Suggested-by: "Ismail, Mustafa" <mustafa.ismail@intel.com>
Signed-off-by: Shifeng Li <lishifeng@sangfor.com.cn>
Reviewed-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
commit 7fed14f upstream.

The following warning appears when using buffered events:

[  203.556451] WARNING: CPU: 53 PID: 10220 at kernel/trace/ring_buffer.c:3912 ring_buffer_discard_commit+0x2eb/0x420
[...]
[  203.670690] CPU: 53 PID: 10220 Comm: stress-ng-sysin Tainted: G            E      6.7.0-rc2-default #4 56e6d0fcf5581e6e51eaaecbdaec2a2338c80f3a
[  203.670704] Hardware name: Intel Corp. GROVEPORT/GROVEPORT, BIOS GVPRCRB1.86B.0016.D04.1705030402 05/03/2017
[  203.670709] RIP: 0010:ring_buffer_discard_commit+0x2eb/0x420
[  203.735721] Code: 4c 8b 4a 50 48 8b 42 48 49 39 c1 0f 84 b3 00 00 00 49 83 e8 01 75 b1 48 8b 42 10 f0 ff 40 08 0f 0b e9 fc fe ff ff f0 ff 47 08 <0f> 0b e9 77 fd ff ff 48 8b 42 10 f0 ff 40 08 0f 0b e9 f5 fe ff ff
[  203.735734] RSP: 0018:ffffb4ae4f7b7d80 EFLAGS: 00010202
[  203.735745] RAX: 0000000000000000 RBX: ffffb4ae4f7b7de0 RCX: ffff8ac10662c000
[  203.735754] RDX: ffff8ac0c750be00 RSI: ffff8ac10662c000 RDI: ffff8ac0c004d400
[  203.781832] RBP: ffff8ac0c039cea0 R08: 0000000000000000 R09: 0000000000000000
[  203.781839] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[  203.781842] R13: ffff8ac10662c000 R14: ffff8ac0c004d400 R15: ffff8ac10662c008
[  203.781846] FS:  00007f4cd8a67740(0000) GS:ffff8ad798880000(0000) knlGS:0000000000000000
[  203.781851] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  203.781855] CR2: 0000559766a74028 CR3: 00000001804c4000 CR4: 00000000001506f0
[  203.781862] Call Trace:
[  203.781870]  <TASK>
[  203.851949]  trace_event_buffer_commit+0x1ea/0x250
[  203.851967]  trace_event_raw_event_sys_enter+0x83/0xe0
[  203.851983]  syscall_trace_enter.isra.0+0x182/0x1a0
[  203.851990]  do_syscall_64+0x3a/0xe0
[  203.852075]  entry_SYSCALL_64_after_hwframe+0x6e/0x76
[  203.852090] RIP: 0033:0x7f4cd870fa77
[  203.982920] Code: 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 90 b8 89 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e9 43 0e 00 f7 d8 64 89 01 48
[  203.982932] RSP: 002b:00007fff99717dd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000089
[  203.982942] RAX: ffffffffffffffda RBX: 0000558ea1d7b6f0 RCX: 00007f4cd870fa77
[  203.982948] RDX: 0000000000000000 RSI: 00007fff99717de0 RDI: 0000558ea1d7b6f0
[  203.982957] RBP: 00007fff99717de0 R08: 00007fff997180e0 R09: 00007fff997180e0
[  203.982962] R10: 00007fff997180e0 R11: 0000000000000246 R12: 00007fff99717f40
[  204.049239] R13: 00007fff99718590 R14: 0000558e9f2127a8 R15: 00007fff997180b0
[  204.049256]  </TASK>

For instance, it can be triggered by running these two commands in
parallel:

 $ while true; do
    echo hist:key=id.syscall:val=hitcount > \
      /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger;
  done
 $ stress-ng --sysinfo $(nproc)

The warning indicates that the current ring_buffer_per_cpu is not in the
committing state. It happens because the active ring_buffer_event
doesn't actually come from the ring_buffer_per_cpu but is allocated from
trace_buffered_event.

The bug is in function trace_buffered_event_disable() where the
following normally happens:

* The code invokes disable_trace_buffered_event() via
  smp_call_function_many() and follows it by synchronize_rcu(). This
  increments the per-CPU variable trace_buffered_event_cnt on each
  target CPU and grants trace_buffered_event_disable() the exclusive
  access to the per-CPU variable trace_buffered_event.

* Maintenance is performed on trace_buffered_event, all per-CPU event
  buffers get freed.

* The code invokes enable_trace_buffered_event() via
  smp_call_function_many(). This decrements trace_buffered_event_cnt and
  releases the access to trace_buffered_event.

A problem is that smp_call_function_many() runs a given function on all
target CPUs except on the current one. The following can then occur:

* Task X executing trace_buffered_event_disable() runs on CPU 0.

* The control reaches synchronize_rcu() and the task gets rescheduled on
  another CPU 1.

* The RCU synchronization finishes. At this point,
  trace_buffered_event_disable() has the exclusive access to all
  trace_buffered_event variables except trace_buffered_event[CPU0]
  because trace_buffered_event_cnt[CPU0] is never incremented and if the
  buffer is currently unused, remains set to 0.

* A different task Y is scheduled on CPU 0 and hits a trace event. The
  code in trace_event_buffer_lock_reserve() sees that
  trace_buffered_event_cnt[CPU0] is set to 0 and decides the use the
  buffer provided by trace_buffered_event[CPU0].

* Task X continues its execution in trace_buffered_event_disable(). The
  code incorrectly frees the event buffer pointed by
  trace_buffered_event[CPU0] and resets the variable to NULL.

* Task Y writes event data to the now freed buffer and later detects the
  created inconsistency.

The issue is observable since commit dea4997 ("tracing: Fix warning
in trace_buffered_event_disable()") which moved the call of
trace_buffered_event_disable() in __ftrace_event_enable_disable()
earlier, prior to invoking call->class->reg(.. TRACE_REG_UNREGISTER ..).
The underlying problem in trace_buffered_event_disable() is however
present since the original implementation in commit 0fc1b09
("tracing: Use temp buffer when filtering events").

Fix the problem by replacing the two smp_call_function_many() calls with
on_each_cpu_mask() which invokes a given callback on all CPUs.

Link: https://lore.kernel.org/all/20231127151248.7232-2-petr.pavlu@suse.com/
Link: https://lkml.kernel.org/r/20231205161736.19663-2-petr.pavlu@suse.com

Cc: stable@vger.kernel.org
Fixes: 0fc1b09 ("tracing: Use temp buffer when filtering events")
Fixes: dea4997 ("tracing: Fix warning in trace_buffered_event_disable()")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
[ Upstream commit a84fbf2 ]

Generating metrics llc_code_read_mpi_demand_plus_prefetch,
llc_data_read_mpi_demand_plus_prefetch,
llc_miss_local_memory_bandwidth_read,
llc_miss_local_memory_bandwidth_write,
nllc_miss_remote_memory_bandwidth_read, memory_bandwidth_read,
memory_bandwidth_write, uncore_frequency, upi_data_transmit_bw,
C2_Pkg_Residency, C3_Core_Residency, C3_Pkg_Residency,
C6_Core_Residency, C6_Pkg_Residency, C7_Core_Residency,
C7_Pkg_Residency, UNCORE_FREQ and tma_info_system_socket_clks would
trigger an address sanitizer heap-buffer-overflows on a SkylakeX.

```
==2567752==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x5020003ed098 at pc 0x5621a816654e bp 0x7fffb55d4da0 sp 0x7fffb55d4d98
READ of size 4 at 0x5020003eee78 thread T0
    #0 0x558265d6654d in aggr_cpu_id__is_empty tools/perf/util/cpumap.c:694:12
    #1 0x558265c914da in perf_stat__get_aggr tools/perf/builtin-stat.c:1490:6
    #2 0x558265c914da in perf_stat__get_global_cached tools/perf/builtin-stat.c:1530:9
    #3 0x558265e53290 in should_skip_zero_counter tools/perf/util/stat-display.c:947:31
    #4 0x558265e53290 in print_counter_aggrdata tools/perf/util/stat-display.c:985:18
    #5 0x558265e51931 in print_counter tools/perf/util/stat-display.c:1110:3
    ayufan-rock64#6 0x558265e51931 in evlist__print_counters tools/perf/util/stat-display.c:1571:5
    ayufan-rock64#7 0x558265c8ec87 in print_counters tools/perf/builtin-stat.c:981:2
    ayufan-rock64#8 0x558265c8cc71 in cmd_stat tools/perf/builtin-stat.c:2837:3
    ayufan-rock64#9 0x558265bb9bd4 in run_builtin tools/perf/perf.c:323:11
    ayufan-rock64#10 0x558265bb98eb in handle_internal_command tools/perf/perf.c:377:8
    ayufan-rock64#11 0x558265bb9389 in run_argv tools/perf/perf.c:421:2
    ayufan-rock64#12 0x558265bb9389 in main tools/perf/perf.c:537:3
```

The issue was the use of testing a cpumap with NULL rather than using
empty, as a map containing the dummy value isn't NULL and the -1
results in an empty aggr map being allocated which legitimately
overflows when any member is accessed.

Fixes: 8a96f45 ("perf stat: Avoid SEGV if core.cpus isn't set")
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230906003912.3317462-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
commit 5a22fbc upstream.

When LAN9303 is MDIO-connected two callchains exist into
mdio->bus->write():

1. switch ports 1&2 ("physical" PHYs):

virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})->
  lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested

2. LAN9303 virtual PHY:

virtual MDIO bus (lan9303_phy_{read|write}) ->
  lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write}

If the latter functions just take
mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP
false-positive splat. It's false-positive because the first
mdio_lock in the second callchain above belongs to virtual MDIO bus, the
second mdio_lock belongs to physical MDIO bus.

Consequent annotation in lan9303_mdio_{read|write} as nested lock
(similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus)
prevents the following splat:

WARNING: possible circular locking dependency detected
5.15.71 #1 Not tainted
------------------------------------------------------
kworker/u4:3/609 is trying to acquire lock:
ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex
but task is already holding lock:
ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&bus->mdio_lock){+.+.}-{3:3}:
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       lan9303_mdio_read
       _regmap_read
       regmap_read
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
-> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}:
       __lock_acquire
       lock_acquire.part.0
       lock_acquire
       __mutex_lock
       mutex_lock_nested
       regmap_lock_mutex
       regmap_read
       lan9303_phy_read
       dsa_slave_phy_read
       __mdiobus_read
       mdiobus_read
       get_phy_device
       mdiobus_scan
       __mdiobus_register
       dsa_register_switch
       lan9303_probe
       lan9303_mdio_probe
       mdio_probe
       really_probe
       __driver_probe_device
       driver_probe_device
       __device_attach_driver
       bus_for_each_drv
       __device_attach
       device_initial_probe
       bus_probe_device
       deferred_probe_work_func
       process_one_work
       worker_thread
       kthread
       ret_from_fork
other info that might help us debug this:
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&bus->mdio_lock);
                               lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
                               lock(&bus->mdio_lock);
  lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock);
*** DEADLOCK ***
5 locks held by kworker/u4:3/609:
 #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work
 #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work
 #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach
 #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch
 #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read
stack backtrace:
CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1
Workqueue: events_unbound deferred_probe_work_func
Call trace:
 dump_backtrace
 show_stack
 dump_stack_lvl
 dump_stack
 print_circular_bug
 check_noncircular
 __lock_acquire
 lock_acquire.part.0
 lock_acquire
 __mutex_lock
 mutex_lock_nested
 regmap_lock_mutex
 regmap_read
 lan9303_phy_read
 dsa_slave_phy_read
 __mdiobus_read
 mdiobus_read
 get_phy_device
 mdiobus_scan
 __mdiobus_register
 dsa_register_switch
 lan9303_probe
 lan9303_mdio_probe
...

Cc: stable@vger.kernel.org
Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support")
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20231027065741.534971-1-alexander.sverdlin@siemens.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
commit d8b90d6 upstream.

When scanning namespaces, it is possible to get valid data from the first
call to nvme_identify_ns() in nvme_alloc_ns(), but not from the second
call in nvme_update_ns_info_block().  In particular, if the NSID becomes
inactive between the two commands, a storage device may return a buffer
filled with zero as per 4.1.5.1.  In this case, we can get a kernel crash
due to a divide-by-zero in blk_stack_limits() because ns->lba_shift will
be set to zero.

PID: 326      TASK: ffff95fec3cd8000  CPU: 29   COMMAND: "kworker/u98:10"
 #0 [ffffad8f8702f9e0] machine_kexec at ffffffff91c76ec7
 #1 [ffffad8f8702fa38] __crash_kexec at ffffffff91dea4fa
 #2 [ffffad8f8702faf8] crash_kexec at ffffffff91deb788
 #3 [ffffad8f8702fb00] oops_end at ffffffff91c2e4bb
 #4 [ffffad8f8702fb20] do_trap at ffffffff91c2a4ce
 #5 [ffffad8f8702fb70] do_error_trap at ffffffff91c2a595
 ayufan-rock64#6 [ffffad8f8702fbb0] exc_divide_error at ffffffff928506e6
 ayufan-rock64#7 [ffffad8f8702fbd0] asm_exc_divide_error at ffffffff92a00926
    [exception RIP: blk_stack_limits+434]
    RIP: ffffffff92191872  RSP: ffffad8f8702fc80  RFLAGS: 00010246
    RAX: 0000000000000000  RBX: ffff95efa0c91800  RCX: 0000000000000001
    RDX: 0000000000000000  RSI: 0000000000000001  RDI: 0000000000000001
    RBP: 00000000ffffffff   R8: ffff95fec7df35a8   R9: 0000000000000000
    R10: 0000000000000000  R11: 0000000000000001  R12: 0000000000000000
    R13: 0000000000000000  R14: 0000000000000000  R15: ffff95fed33c09a8
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 ayufan-rock64#8 [ffffad8f8702fce0] nvme_update_ns_info_block at ffffffffc06d3533 [nvme_core]
 ayufan-rock64#9 [ffffad8f8702fd18] nvme_scan_ns at ffffffffc06d6fa7 [nvme_core]

This happened when the check for valid data was moved out of nvme_identify_ns()
into one of the callers.  Fix this by checking in both callers.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=218186
Fixes: 0dd6fff ("nvme: bring back auto-removal of deleted namespaces during sequential scan")
Cc: stable@vger.kernel.org
Signed-off-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
[ Upstream commit e3e82fc ]

When creating ceq_0 during probing irdma, cqp.sc_cqp will be sent as a
cqp_request to cqp->sc_cqp.sq_ring. If the request is pending when
removing the irdma driver or unplugging its aux device, cqp.sc_cqp will be
dereferenced as wrong struct in irdma_free_pending_cqp_request().

  PID: 3669   TASK: ffff88aef892c000  CPU: 28  COMMAND: "kworker/28:0"
   #0 [fffffe0000549e38] crash_nmi_callback at ffffffff810e3a34
   #1 [fffffe0000549e40] nmi_handle at ffffffff810788b2
   #2 [fffffe0000549ea0] default_do_nmi at ffffffff8107938f
   #3 [fffffe0000549eb8] do_nmi at ffffffff81079582
   #4 [fffffe0000549ef0] end_repeat_nmi at ffffffff82e016b4
      [exception RIP: native_queued_spin_lock_slowpath+1291]
      RIP: ffffffff8127e72b  RSP: ffff88aa841ef778  RFLAGS: 00000046
      RAX: 0000000000000000  RBX: ffff88b01f849700  RCX: ffffffff8127e47e
      RDX: 0000000000000000  RSI: 0000000000000004  RDI: ffffffff83857ec0
      RBP: ffff88afe3e4efc8   R8: ffffed15fc7c9dfa   R9: ffffed15fc7c9dfa
      R10: 0000000000000001  R11: ffffed15fc7c9df9  R12: 0000000000740000
      R13: ffff88b01f849708  R14: 0000000000000003  R15: ffffed1603f092e1
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0000
  -- <NMI exception stack> --
   #5 [ffff88aa841ef778] native_queued_spin_lock_slowpath at ffffffff8127e72b
   ayufan-rock64#6 [ffff88aa841ef7b0] _raw_spin_lock_irqsave at ffffffff82c22aa4
   ayufan-rock64#7 [ffff88aa841ef7c8] __wake_up_common_lock at ffffffff81257363
   ayufan-rock64#8 [ffff88aa841ef888] irdma_free_pending_cqp_request at ffffffffa0ba12cc [irdma]
   ayufan-rock64#9 [ffff88aa841ef958] irdma_cleanup_pending_cqp_op at ffffffffa0ba1469 [irdma]
   ayufan-rock64#10 [ffff88aa841ef9c0] irdma_ctrl_deinit_hw at ffffffffa0b2989f [irdma]
   ayufan-rock64#11 [ffff88aa841efa28] irdma_remove at ffffffffa0b252df [irdma]
   ayufan-rock64#12 [ffff88aa841efae8] auxiliary_bus_remove at ffffffff8219afdb
   ayufan-rock64#13 [ffff88aa841efb00] device_release_driver_internal at ffffffff821882e6
   ayufan-rock64#14 [ffff88aa841efb38] bus_remove_device at ffffffff82184278
   ayufan-rock64#15 [ffff88aa841efb88] device_del at ffffffff82179d23
   ayufan-rock64#16 [ffff88aa841efc48] ice_unplug_aux_dev at ffffffffa0eb1c14 [ice]
   ayufan-rock64#17 [ffff88aa841efc68] ice_service_task at ffffffffa0d88201 [ice]
   ayufan-rock64#18 [ffff88aa841efde8] process_one_work at ffffffff811c589a
   ayufan-rock64#19 [ffff88aa841efe60] worker_thread at ffffffff811c71ff
   ayufan-rock64#20 [ffff88aa841eff10] kthread at ffffffff811d87a0
   ayufan-rock64#21 [ffff88aa841eff50] ret_from_fork at ffffffff82e0022f

Fixes: 44d9e52 ("RDMA/irdma: Implement device initialization definitions")
Link: https://lore.kernel.org/r/20231130081415.891006-1-lishifeng@sangfor.com.cn
Suggested-by: "Ismail, Mustafa" <mustafa.ismail@intel.com>
Signed-off-by: Shifeng Li <lishifeng@sangfor.com.cn>
Reviewed-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
commit 7fed14f upstream.

The following warning appears when using buffered events:

[  203.556451] WARNING: CPU: 53 PID: 10220 at kernel/trace/ring_buffer.c:3912 ring_buffer_discard_commit+0x2eb/0x420
[...]
[  203.670690] CPU: 53 PID: 10220 Comm: stress-ng-sysin Tainted: G            E      6.7.0-rc2-default #4 56e6d0fcf5581e6e51eaaecbdaec2a2338c80f3a
[  203.670704] Hardware name: Intel Corp. GROVEPORT/GROVEPORT, BIOS GVPRCRB1.86B.0016.D04.1705030402 05/03/2017
[  203.670709] RIP: 0010:ring_buffer_discard_commit+0x2eb/0x420
[  203.735721] Code: 4c 8b 4a 50 48 8b 42 48 49 39 c1 0f 84 b3 00 00 00 49 83 e8 01 75 b1 48 8b 42 10 f0 ff 40 08 0f 0b e9 fc fe ff ff f0 ff 47 08 <0f> 0b e9 77 fd ff ff 48 8b 42 10 f0 ff 40 08 0f 0b e9 f5 fe ff ff
[  203.735734] RSP: 0018:ffffb4ae4f7b7d80 EFLAGS: 00010202
[  203.735745] RAX: 0000000000000000 RBX: ffffb4ae4f7b7de0 RCX: ffff8ac10662c000
[  203.735754] RDX: ffff8ac0c750be00 RSI: ffff8ac10662c000 RDI: ffff8ac0c004d400
[  203.781832] RBP: ffff8ac0c039cea0 R08: 0000000000000000 R09: 0000000000000000
[  203.781839] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[  203.781842] R13: ffff8ac10662c000 R14: ffff8ac0c004d400 R15: ffff8ac10662c008
[  203.781846] FS:  00007f4cd8a67740(0000) GS:ffff8ad798880000(0000) knlGS:0000000000000000
[  203.781851] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  203.781855] CR2: 0000559766a74028 CR3: 00000001804c4000 CR4: 00000000001506f0
[  203.781862] Call Trace:
[  203.781870]  <TASK>
[  203.851949]  trace_event_buffer_commit+0x1ea/0x250
[  203.851967]  trace_event_raw_event_sys_enter+0x83/0xe0
[  203.851983]  syscall_trace_enter.isra.0+0x182/0x1a0
[  203.851990]  do_syscall_64+0x3a/0xe0
[  203.852075]  entry_SYSCALL_64_after_hwframe+0x6e/0x76
[  203.852090] RIP: 0033:0x7f4cd870fa77
[  203.982920] Code: 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 90 b8 89 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e9 43 0e 00 f7 d8 64 89 01 48
[  203.982932] RSP: 002b:00007fff99717dd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000089
[  203.982942] RAX: ffffffffffffffda RBX: 0000558ea1d7b6f0 RCX: 00007f4cd870fa77
[  203.982948] RDX: 0000000000000000 RSI: 00007fff99717de0 RDI: 0000558ea1d7b6f0
[  203.982957] RBP: 00007fff99717de0 R08: 00007fff997180e0 R09: 00007fff997180e0
[  203.982962] R10: 00007fff997180e0 R11: 0000000000000246 R12: 00007fff99717f40
[  204.049239] R13: 00007fff99718590 R14: 0000558e9f2127a8 R15: 00007fff997180b0
[  204.049256]  </TASK>

For instance, it can be triggered by running these two commands in
parallel:

 $ while true; do
    echo hist:key=id.syscall:val=hitcount > \
      /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger;
  done
 $ stress-ng --sysinfo $(nproc)

The warning indicates that the current ring_buffer_per_cpu is not in the
committing state. It happens because the active ring_buffer_event
doesn't actually come from the ring_buffer_per_cpu but is allocated from
trace_buffered_event.

The bug is in function trace_buffered_event_disable() where the
following normally happens:

* The code invokes disable_trace_buffered_event() via
  smp_call_function_many() and follows it by synchronize_rcu(). This
  increments the per-CPU variable trace_buffered_event_cnt on each
  target CPU and grants trace_buffered_event_disable() the exclusive
  access to the per-CPU variable trace_buffered_event.

* Maintenance is performed on trace_buffered_event, all per-CPU event
  buffers get freed.

* The code invokes enable_trace_buffered_event() via
  smp_call_function_many(). This decrements trace_buffered_event_cnt and
  releases the access to trace_buffered_event.

A problem is that smp_call_function_many() runs a given function on all
target CPUs except on the current one. The following can then occur:

* Task X executing trace_buffered_event_disable() runs on CPU 0.

* The control reaches synchronize_rcu() and the task gets rescheduled on
  another CPU 1.

* The RCU synchronization finishes. At this point,
  trace_buffered_event_disable() has the exclusive access to all
  trace_buffered_event variables except trace_buffered_event[CPU0]
  because trace_buffered_event_cnt[CPU0] is never incremented and if the
  buffer is currently unused, remains set to 0.

* A different task Y is scheduled on CPU 0 and hits a trace event. The
  code in trace_event_buffer_lock_reserve() sees that
  trace_buffered_event_cnt[CPU0] is set to 0 and decides the use the
  buffer provided by trace_buffered_event[CPU0].

* Task X continues its execution in trace_buffered_event_disable(). The
  code incorrectly frees the event buffer pointed by
  trace_buffered_event[CPU0] and resets the variable to NULL.

* Task Y writes event data to the now freed buffer and later detects the
  created inconsistency.

The issue is observable since commit dea4997 ("tracing: Fix warning
in trace_buffered_event_disable()") which moved the call of
trace_buffered_event_disable() in __ftrace_event_enable_disable()
earlier, prior to invoking call->class->reg(.. TRACE_REG_UNREGISTER ..).
The underlying problem in trace_buffered_event_disable() is however
present since the original implementation in commit 0fc1b09
("tracing: Use temp buffer when filtering events").

Fix the problem by replacing the two smp_call_function_many() calls with
on_each_cpu_mask() which invokes a given callback on all CPUs.

Link: https://lore.kernel.org/all/20231127151248.7232-2-petr.pavlu@suse.com/
Link: https://lkml.kernel.org/r/20231205161736.19663-2-petr.pavlu@suse.com

Cc: stable@vger.kernel.org
Fixes: 0fc1b09 ("tracing: Use temp buffer when filtering events")
Fixes: dea4997 ("tracing: Fix warning in trace_buffered_event_disable()")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Dec 19, 2023
…mplaint

[ Upstream commit bbaa6ff ]

AMD PMF driver can cause the following warning:
[  196.159546] ------------[ cut here ]------------
[  196.159556] Voluntary context switch within RCU read-side critical section!
[  196.159571] WARNING: CPU: 0 PID: 9 at kernel/rcu/tree_plugin.h:320 rcu_note_context_switch+0x43d/0x560
[  196.159604] Modules linked in: nvme_fabrics ccm rfcomm snd_hda_scodec_cs35l41_spi cmac algif_hash algif_skcipher af_alg bnep joydev btusb btrtl uvcvideo btintel btbcm videobuf2_vmalloc intel_rapl_msr btmtk videobuf2_memops uvc videobuf2_v4l2 intel_rapl_common binfmt_misc hid_sensor_als snd_sof_amd_vangogh hid_sensor_trigger bluetooth industrialio_triggered_buffer videodev snd_sof_amd_rembrandt hid_sensor_iio_common amdgpu ecdh_generic kfifo_buf videobuf2_common hp_wmi kvm_amd sparse_keymap snd_sof_amd_renoir wmi_bmof industrialio ecc mc nls_iso8859_1 kvm snd_sof_amd_acp irqbypass snd_sof_xtensa_dsp crct10dif_pclmul crc32_pclmul mt7921e snd_sof_pci snd_ctl_led polyval_clmulni mt7921_common polyval_generic snd_sof ghash_clmulni_intel mt792x_lib mt76_connac_lib sha512_ssse3 snd_sof_utils aesni_intel snd_hda_codec_realtek crypto_simd mt76 snd_hda_codec_generic cryptd snd_soc_core snd_hda_codec_hdmi rapl ledtrig_audio input_leds snd_compress i2c_algo_bit drm_ttm_helper mac80211 snd_pci_ps hid_multitouch ttm drm_exec
[  196.159970]  drm_suballoc_helper snd_rpl_pci_acp6x amdxcp drm_buddy snd_hda_intel snd_acp_pci snd_hda_scodec_cs35l41_i2c serio_raw gpu_sched snd_hda_scodec_cs35l41 snd_acp_legacy_common snd_intel_dspcfg snd_hda_cs_dsp_ctls snd_hda_codec libarc4 drm_display_helper snd_pci_acp6x cs_dsp snd_hwdep snd_soc_cs35l41_lib video k10temp snd_pci_acp5x thunderbolt snd_hda_core drm_kms_helper cfg80211 snd_seq snd_rn_pci_acp3x snd_pcm snd_acp_config cec snd_soc_acpi snd_seq_device rc_core ccp snd_pci_acp3x snd_timer snd soundcore wmi amd_pmf platform_profile amd_pmc mac_hid serial_multi_instantiate wireless_hotkey hid_sensor_hub sch_fq_codel msr parport_pc ppdev lp parport efi_pstore ip_tables x_tables autofs4 btrfs blake2b_generic raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx libcrc32c xor raid6_pq raid1 raid0 multipath linear dm_mirror dm_region_hash dm_log cdc_ether usbnet r8152 mii hid_generic nvme i2c_hid_acpi i2c_hid nvme_core i2c_piix4 xhci_pci amd_sfh drm xhci_pci_renesas nvme_common hid
[  196.160382] CPU: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.6.0-rc1 #4
[  196.160397] Hardware name: HP HP EliteBook 845 14 inch G10 Notebook PC/8B6E, BIOS V82 Ver. 01.02.00 08/24/2023
[  196.160405] Workqueue: events power_supply_changed_work
[  196.160426] RIP: 0010:rcu_note_context_switch+0x43d/0x560
[  196.160440] Code: 00 48 89 be 40 08 00 00 48 89 86 48 08 00 00 48 89 10 e9 63 fe ff ff 48 c7 c7 10 e7 b0 9e c6 05 e8 d8 20 02 01 e8 13 0f f3 ff <0f> 0b e9 27 fc ff ff a9 ff ff ff 7f 0f 84 cf fc ff ff 65 48 8b 3c
[  196.160450] RSP: 0018:ffffc900001878f0 EFLAGS: 00010046
[  196.160462] RAX: 0000000000000000 RBX: ffff88885e834040 RCX: 0000000000000000
[  196.160470] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[  196.160476] RBP: ffffc90000187910 R08: 0000000000000000 R09: 0000000000000000
[  196.160482] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[  196.160488] R13: 0000000000000000 R14: ffff888100990000 R15: ffff888100990000
[  196.160495] FS:  0000000000000000(0000) GS:ffff88885e800000(0000) knlGS:0000000000000000
[  196.160504] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  196.160512] CR2: 000055cb053c8246 CR3: 000000013443a000 CR4: 0000000000750ef0
[  196.160520] PKRU: 55555554
[  196.160526] Call Trace:
[  196.160532]  <TASK>
[  196.160548]  ? show_regs+0x72/0x90
[  196.160570]  ? rcu_note_context_switch+0x43d/0x560
[  196.160580]  ? __warn+0x8d/0x160
[  196.160600]  ? rcu_note_context_switch+0x43d/0x560
[  196.160613]  ? report_bug+0x1bb/0x1d0
[  196.160637]  ? handle_bug+0x46/0x90
[  196.160658]  ? exc_invalid_op+0x19/0x80
[  196.160675]  ? asm_exc_invalid_op+0x1b/0x20
[  196.160709]  ? rcu_note_context_switch+0x43d/0x560
[  196.160727]  __schedule+0xb9/0x15f0
[  196.160746]  ? srso_alias_return_thunk+0x5/0x7f
[  196.160765]  ? srso_alias_return_thunk+0x5/0x7f
[  196.160778]  ? acpi_ns_search_one_scope+0xbe/0x270
[  196.160806]  schedule+0x68/0x110
[  196.160820]  schedule_timeout+0x151/0x160
[  196.160829]  ? srso_alias_return_thunk+0x5/0x7f
[  196.160842]  ? srso_alias_return_thunk+0x5/0x7f
[  196.160855]  ? acpi_ns_lookup+0x3c5/0xa90
[  196.160878]  __down_common+0xff/0x220
[  196.160905]  __down_timeout+0x16/0x30
[  196.160920]  down_timeout+0x64/0x70
[  196.160938]  acpi_os_wait_semaphore+0x85/0x200
[  196.160959]  acpi_ut_acquire_mutex+0x9e/0x280
[  196.160979]  acpi_ex_enter_interpreter+0x2d/0xb0
[  196.160992]  acpi_ns_evaluate+0x2f0/0x5f0
[  196.161005]  acpi_evaluate_object+0x172/0x490
[  196.161018]  ? acpi_os_signal_semaphore+0x8a/0xd0
[  196.161038]  acpi_evaluate_integer+0x52/0xe0
[  196.161055]  ? kfree+0x79/0x120
[  196.161071]  ? srso_alias_return_thunk+0x5/0x7f
[  196.161089]  acpi_ac_get_state.part.0+0x27/0x80
[  196.161110]  get_ac_property+0x5c/0x70
[  196.161127]  ? __pfx___power_supply_is_system_supplied+0x10/0x10
[  196.161146]  __power_supply_is_system_supplied+0x44/0xb0
[  196.161166]  class_for_each_device+0x124/0x160
[  196.161184]  ? acpi_ac_get_state.part.0+0x27/0x80
[  196.161203]  ? srso_alias_return_thunk+0x5/0x7f
[  196.161223]  power_supply_is_system_supplied+0x3c/0x70
[  196.161243]  amd_pmf_get_power_source+0xe/0x20 [amd_pmf]
[  196.161276]  amd_pmf_power_slider_update_event+0x49/0x90 [amd_pmf]
[  196.161310]  amd_pmf_pwr_src_notify_call+0xe7/0x100 [amd_pmf]
[  196.161340]  notifier_call_chain+0x5f/0xe0
[  196.161362]  atomic_notifier_call_chain+0x33/0x60
[  196.161378]  power_supply_changed_work+0x84/0x110
[  196.161394]  process_one_work+0x178/0x360
[  196.161412]  ? __pfx_worker_thread+0x10/0x10
[  196.161424]  worker_thread+0x307/0x430
[  196.161440]  ? __pfx_worker_thread+0x10/0x10
[  196.161451]  kthread+0xf4/0x130
[  196.161467]  ? __pfx_kthread+0x10/0x10
[  196.161486]  ret_from_fork+0x43/0x70
[  196.161502]  ? __pfx_kthread+0x10/0x10
[  196.161518]  ret_from_fork_asm+0x1b/0x30
[  196.161558]  </TASK>
[  196.161562] ---[ end trace 0000000000000000 ]---

Since there's no guarantee that all the callbacks can work in atomic
context, switch to use blocking_notifier_call_chain to relax the
constraint.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Reported-by: Allen Zhong <allen@atr.me>
Fixes: 4c71ae4 ("platform/x86/amd/pmf: Add support SPS PMF feature")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217571
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20230913033233.602986-1-kai.heng.feng@canonical.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
scpcom referenced this pull request in scpcom/linux Jan 26, 2024
commit 5d515ee upstream.

The kernel warning message is triggered, when SPR MCC is used.

[   17.945331] ------------[ cut here ]------------
[   17.946305] WARNING: CPU: 65 PID: 1 at
arch/x86/events/intel/uncore_discovery.c:184
intel_uncore_has_discovery_tables+0x4c0/0x65c
[   17.946305] Modules linked in:
[   17.946305] CPU: 65 PID: 1 Comm: swapper/0 Not tainted
5.4.17-2136.313.1-X10-2c+ #4

It's caused by the broken discovery table of UPI.

The discovery tables are from hardware. Except for dropping the broken
information, there is nothing Linux can do. Using WARN_ON_ONCE() is
overkilled.

Use the pr_info() to replace WARN_ON_ONCE(), and specify what uncore unit
is dropped and the reason.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Petlan <mpetlan@redhat.com>
Link: https://lore.kernel.org/r/20230112200105.733466-6-kan.liang@linux.intel.com
Cc: Mahmoud Adam <mngyadam@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Jan 27, 2024
commit 5d515ee upstream.

The kernel warning message is triggered, when SPR MCC is used.

[   17.945331] ------------[ cut here ]------------
[   17.946305] WARNING: CPU: 65 PID: 1 at
arch/x86/events/intel/uncore_discovery.c:184
intel_uncore_has_discovery_tables+0x4c0/0x65c
[   17.946305] Modules linked in:
[   17.946305] CPU: 65 PID: 1 Comm: swapper/0 Not tainted
5.4.17-2136.313.1-X10-2c+ #4

It's caused by the broken discovery table of UPI.

The discovery tables are from hardware. Except for dropping the broken
information, there is nothing Linux can do. Using WARN_ON_ONCE() is
overkilled.

Use the pr_info() to replace WARN_ON_ONCE(), and specify what uncore unit
is dropped and the reason.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Petlan <mpetlan@redhat.com>
Link: https://lore.kernel.org/r/20230112200105.733466-6-kan.liang@linux.intel.com
Cc: Mahmoud Adam <mngyadam@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scpcom referenced this pull request in scpcom/linux Feb 25, 2024
[ Upstream commit fc3a553 ]

An issue occurred while reading an ELF file in libbpf.c during fuzzing:

	Program received signal SIGSEGV, Segmentation fault.
	0x0000000000958e97 in bpf_object.collect_prog_relos () at libbpf.c:4206
	4206 in libbpf.c
	(gdb) bt
	#0 0x0000000000958e97 in bpf_object.collect_prog_relos () at libbpf.c:4206
	#1 0x000000000094f9d6 in bpf_object.collect_relos () at libbpf.c:6706
	#2 0x000000000092bef3 in bpf_object_open () at libbpf.c:7437
	#3 0x000000000092c046 in bpf_object.open_mem () at libbpf.c:7497
	#4 0x0000000000924afa in LLVMFuzzerTestOneInput () at fuzz/bpf-object-fuzzer.c:16
	#5 0x000000000060be11 in testblitz_engine::fuzzer::Fuzzer::run_one ()
	ayufan-rock64#6 0x000000000087ad92 in tracing::span::Span::in_scope ()
	ayufan-rock64#7 0x00000000006078aa in testblitz_engine::fuzzer::util::walkdir ()
	ayufan-rock64#8 0x00000000005f3217 in testblitz_engine::entrypoint::main::{{closure}} ()
	ayufan-rock64#9 0x00000000005f2601 in main ()
	(gdb)

scn_data was null at this code(tools/lib/bpf/src/libbpf.c):

	if (rel->r_offset % BPF_INSN_SZ || rel->r_offset >= scn_data->d_size) {

The scn_data is derived from the code above:

	scn = elf_sec_by_idx(obj, sec_idx);
	scn_data = elf_sec_data(obj, scn);

	relo_sec_name = elf_sec_str(obj, shdr->sh_name);
	sec_name = elf_sec_name(obj, scn);
	if (!relo_sec_name || !sec_name)// don't check whether scn_data is NULL
		return -EINVAL;

In certain special scenarios, such as reading a malformed ELF file,
it is possible that scn_data may be a null pointer

Signed-off-by: Mingyi Zhang <zhangmingyi5@huawei.com>
Signed-off-by: Xin Liu <liuxin350@huawei.com>
Signed-off-by: Changye Wu <wuchangye@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20231221033947.154564-1-liuxin350@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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