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build.sh and README.md updates #48

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merged 4 commits into from
Nov 5, 2018
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@lkilo lkilo commented Nov 5, 2018

Updated some small things in built.sh and README.md.

@frank-w frank-w merged commit 7d3facd into frank-w:4.14-main Nov 5, 2018
frank-w pushed a commit that referenced this pull request Dec 17, 2018
Increase kasan instrumented kernel stack size from 32k to 64k. Other
architectures seems to get away with just doubling kernel stack size under
kasan, but on s390 this appears to be not enough due to bigger frame size.
The particular pain point is kasan inlined checks (CONFIG_KASAN_INLINE
vs CONFIG_KASAN_OUTLINE). With inlined checks one particular case hitting
stack overflow is fs sync on xfs filesystem:

 #0 [9a0681e8]  704 bytes  check_usage at 34b1fc
 #1 [9a0684a8]  432 bytes  check_usage at 34c710
 #2 [9a068658]  1048 bytes  validate_chain at 35044a
 #3 [9a068a70]  312 bytes  __lock_acquire at 3559fe
 #4 [9a068ba8]  440 bytes  lock_acquire at 3576ee
 #5 [9a068d60]  104 bytes  _raw_spin_lock at 21b44e0
 #6 [9a068dc8]  1992 bytes  enqueue_entity at 2dbf72
 #7 [9a069590]  1496 bytes  enqueue_task_fair at 2df5f0
 #8 [9a069b68]  64 bytes  ttwu_do_activate at 28f438
 #9 [9a069ba8]  552 bytes  try_to_wake_up at 298c4c
 #10 [9a069dd0]  168 bytes  wake_up_worker at 23f97c
 #11 [9a069e78]  200 bytes  insert_work at 23fc2e
 #12 [9a069f40]  648 bytes  __queue_work at 2487c0
 #13 [9a06a1c8]  200 bytes  __queue_delayed_work at 24db28
 #14 [9a06a290]  248 bytes  mod_delayed_work_on at 24de84
 #15 [9a06a388]  24 bytes  kblockd_mod_delayed_work_on at 153e2a0
 #16 [9a06a3a0]  288 bytes  __blk_mq_delay_run_hw_queue at 158168c
 #17 [9a06a4c0]  192 bytes  blk_mq_run_hw_queue at 1581a3c
 #18 [9a06a580]  184 bytes  blk_mq_sched_insert_requests at 15a2192
 #19 [9a06a638]  1024 bytes  blk_mq_flush_plug_list at 1590f3a
 #20 [9a06aa38]  704 bytes  blk_flush_plug_list at 1555028
 #21 [9a06acf8]  320 bytes  schedule at 219e476
 #22 [9a06ae38]  760 bytes  schedule_timeout at 21b0aac
 #23 [9a06b130]  408 bytes  wait_for_common at 21a1706
 #24 [9a06b2c8]  360 bytes  xfs_buf_iowait at fa1540
 #25 [9a06b430]  256 bytes  __xfs_buf_submit at fadae6
 #26 [9a06b530]  264 bytes  xfs_buf_read_map at fae3f6
 #27 [9a06b638]  656 bytes  xfs_trans_read_buf_map at 10ac9a8
 #28 [9a06b8c8]  304 bytes  xfs_btree_kill_root at e72426
 #29 [9a06b9f8]  288 bytes  xfs_btree_lookup_get_block at e7bc5e
 #30 [9a06bb18]  624 bytes  xfs_btree_lookup at e7e1a6
 #31 [9a06bd88]  2664 bytes  xfs_alloc_ag_vextent_near at dfa070
 #32 [9a06c7f0]  144 bytes  xfs_alloc_ag_vextent at dff3ca
 #33 [9a06c880]  1128 bytes  xfs_alloc_vextent at e05fce
 #34 [9a06cce8]  584 bytes  xfs_bmap_btalloc at e58342
 #35 [9a06cf30]  1336 bytes  xfs_bmapi_write at e618de
 #36 [9a06d468]  776 bytes  xfs_iomap_write_allocate at ff678e
 #37 [9a06d770]  720 bytes  xfs_map_blocks at f82af8
 #38 [9a06da40]  928 bytes  xfs_writepage_map at f83cd6
 #39 [9a06dde0]  320 bytes  xfs_do_writepage at f85872
 #40 [9a06df20]  1320 bytes  write_cache_pages at 73dfe8
 #41 [9a06e448]  208 bytes  xfs_vm_writepages at f7f892
 #42 [9a06e518]  88 bytes  do_writepages at 73fe6a
 #43 [9a06e570]  872 bytes  __writeback_single_inode at a20cb6
 #44 [9a06e8d8]  664 bytes  writeback_sb_inodes at a23be2
 #45 [9a06eb70]  296 bytes  __writeback_inodes_wb at a242e0
 #46 [9a06ec98]  928 bytes  wb_writeback at a2500e
 #47 [9a06f038]  848 bytes  wb_do_writeback at a260ae
 #48 [9a06f388]  536 bytes  wb_workfn at a28228
 #49 [9a06f5a0]  1088 bytes  process_one_work at 24a234
 #50 [9a06f9e0]  1120 bytes  worker_thread at 24ba26
 #51 [9a06fe40]  104 bytes  kthread at 26545a
 #52 [9a06fea8]             kernel_thread_starter at 21b6b62

To be able to increase the stack size to 64k reuse LLILL instruction
in __switch_to function to load 64k - STACK_FRAME_OVERHEAD - __PT_SIZE
(65192) value as unsigned.

Reported-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
frank-w pushed a commit that referenced this pull request Dec 17, 2018
After commit 3c83dd5 ("wlcore: Add support for optional
wakeirq") landed upstream, I started seeing the following oops
on my HiKey board:

[    1.870279] Unable to handle kernel read from unreadable memory at virtual address 0000000000000010
[    1.870283] Mem abort info:
[    1.870287]   ESR = 0x96000005
[    1.870292]   Exception class = DABT (current EL), IL = 32 bits
[    1.870296]   SET = 0, FnV = 0
[    1.870299]   EA = 0, S1PTW = 0
[    1.870302] Data abort info:
[    1.870306]   ISV = 0, ISS = 0x00000005
[    1.870309]   CM = 0, WnR = 0
[    1.870312] [0000000000000010] user address but active_mm is swapper
[    1.870318] Internal error: Oops: 96000005 [#1] PREEMPT SMP
[    1.870327] CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 4.19.0-05129-gb3d1e8e #48
[    1.870331] Hardware name: HiKey Development Board (DT)
[    1.870350] Workqueue: events_freezable mmc_rescan
[    1.870358] pstate: 60400005 (nZCv daif +PAN -UAO)
[    1.870366] pc : wl1271_probe+0x210/0x350
[    1.870371] lr : wl1271_probe+0x210/0x350
[    1.870374] sp : ffffff80080739b0
[    1.870377] x29: ffffff80080739b0 x28: 0000000000000000
[    1.870384] x27: 0000000000000000 x26: 0000000000000000
[    1.870391] x25: 0000000000000036 x24: ffffffc074ecb598
[    1.870398] x23: ffffffc07ffdce78 x22: ffffffc0744ed808
[    1.870404] x21: ffffffc074ecbb98 x20: ffffff8008ff9000
[    1.870411] x19: ffffffc0744ed800 x18: ffffff8008ff9a48
[    1.870418] x17: 0000000000000000 x16: 0000000000000000
[    1.870425] x15: ffffffc074ecb503 x14: ffffffffffffffff
[    1.870431] x13: ffffffc074ecb502 x12: 0000000000000030
[    1.870438] x11: 0101010101010101 x10: 0000000000000040
[    1.870444] x9 : ffffffc075400248 x8 : ffffffc075400270
[    1.870451] x7 : 0000000000000000 x6 : 0000000000000000
[    1.870457] x5 : 0000000000000000 x4 : 0000000000000000
[    1.870463] x3 : 0000000000000000 x2 : 0000000000000000
[    1.870469] x1 : 0000000000000028 x0 : 0000000000000000
[    1.870477] Process kworker/0:0 (pid: 5, stack limit = 0x(____ptrval____))
[    1.870480] Call trace:
[    1.870485]  wl1271_probe+0x210/0x350
[    1.870491]  sdio_bus_probe+0x100/0x128
[    1.870500]  really_probe+0x1a8/0x2b8
[    1.870506]  driver_probe_device+0x58/0x100
[    1.870511]  __device_attach_driver+0x94/0xd8
[    1.870517]  bus_for_each_drv+0x70/0xc8
[    1.870522]  __device_attach+0xe0/0x140
[    1.870527]  device_initial_probe+0x10/0x18
[    1.870532]  bus_probe_device+0x94/0xa0
[    1.870537]  device_add+0x374/0x5b8
[    1.870542]  sdio_add_func+0x60/0x88
[    1.870546]  mmc_attach_sdio+0x1b0/0x358
[    1.870551]  mmc_rescan+0x2cc/0x390
[    1.870558]  process_one_work+0x12c/0x320
[    1.870563]  worker_thread+0x48/0x458
[    1.870569]  kthread+0xf8/0x128
[    1.870575]  ret_from_fork+0x10/0x18
[    1.870583] Code: 92400c21 b2760021 a90687a2 97e95bf9 (f9400803)
[    1.870587] ---[ end trace 1e15f81d3c139ca9 ]---

It seems since we don't have a wakeirq value in the dts, the wakeirq
value in wl1271_probe() is zero, which then causes trouble in
irqd_get_trigger_type(irq_get_irq_data(wakeirq)).

This patch tries to address this by checking if wakeirq is zero,
and not trying to add it to the resources if that is the case.

Fixes: 3c83dd5 ("wlcore: Add support for optional wakeirq")
Cc: Tony Lindgren <tony@atomide.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Eyal Reizer <eyalr@ti.com>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: linux-wireless@vger.kernel.org
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
frank-w pushed a commit that referenced this pull request May 9, 2020
…f fs_info::journal_info

[BUG]
One run of btrfs/063 triggered the following lockdep warning:
  ============================================
  WARNING: possible recursive locking detected
  5.6.0-rc7-custom+ #48 Not tainted
  --------------------------------------------
  kworker/u24:0/7 is trying to acquire lock:
  ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]

  but task is already holding lock:
  ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]

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

         CPU0
         ----
    lock(sb_internal#2);
    lock(sb_internal#2);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  4 locks held by kworker/u24:0/7:
   #0: ffff88817b495948 ((wq_completion)btrfs-endio-write){+.+.}, at: process_one_work+0x557/0xb80
   #1: ffff888189ea7db8 ((work_completion)(&work->normal_work)){+.+.}, at: process_one_work+0x557/0xb80
   #2: ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
   #3: ffff888174ca4da8 (&fs_info->reloc_mutex){+.+.}, at: btrfs_record_root_in_trans+0x83/0xd0 [btrfs]

  stack backtrace:
  CPU: 0 PID: 7 Comm: kworker/u24:0 Not tainted 5.6.0-rc7-custom+ #48
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
  Call Trace:
   dump_stack+0xc2/0x11a
   __lock_acquire.cold+0xce/0x214
   lock_acquire+0xe6/0x210
   __sb_start_write+0x14e/0x290
   start_transaction+0x66c/0x890 [btrfs]
   btrfs_join_transaction+0x1d/0x20 [btrfs]
   find_free_extent+0x1504/0x1a50 [btrfs]
   btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
   btrfs_alloc_tree_block+0x1ac/0x570 [btrfs]
   btrfs_copy_root+0x213/0x580 [btrfs]
   create_reloc_root+0x3bd/0x470 [btrfs]
   btrfs_init_reloc_root+0x2d2/0x310 [btrfs]
   record_root_in_trans+0x191/0x1d0 [btrfs]
   btrfs_record_root_in_trans+0x90/0xd0 [btrfs]
   start_transaction+0x16e/0x890 [btrfs]
   btrfs_join_transaction+0x1d/0x20 [btrfs]
   btrfs_finish_ordered_io+0x55d/0xcd0 [btrfs]
   finish_ordered_fn+0x15/0x20 [btrfs]
   btrfs_work_helper+0x116/0x9a0 [btrfs]
   process_one_work+0x632/0xb80
   worker_thread+0x80/0x690
   kthread+0x1a3/0x1f0
   ret_from_fork+0x27/0x50

It's pretty hard to reproduce, only one hit so far.

[CAUSE]
This is because we're calling btrfs_join_transaction() without re-using
the current running one:

btrfs_finish_ordered_io()
|- btrfs_join_transaction()		<<< Call #1
   |- btrfs_record_root_in_trans()
      |- btrfs_reserve_extent()
	 |- btrfs_join_transaction()	<<< Call #2

Normally such btrfs_join_transaction() call should re-use the existing
one, without trying to re-start a transaction.

But the problem is, in btrfs_join_transaction() call #1, we call
btrfs_record_root_in_trans() before initializing current::journal_info.

And in btrfs_join_transaction() call #2, we're relying on
current::journal_info to avoid such deadlock.

[FIX]
Call btrfs_record_root_in_trans() after we have initialized
current::journal_info.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
frank-w pushed a commit that referenced this pull request May 9, 2020
[ Upstream commit dd09fad ]

Commit:

  3a6b6c6 ("efi: Make EFI_MEMORY_ATTRIBUTES_TABLE initialization common across all architectures")

moved the call to efi_memattr_init() from ARM specific to the generic
EFI init code, in order to be able to apply the restricted permissions
described in that table on x86 as well.

We never enabled this feature fully on i386, and so mapping and
reserving this table is pointless. However, due to the early call to
memblock_reserve(), the memory bookkeeping gets confused to the point
where it produces the splat below when we try to map the memory later
on:

  ------------[ cut here ]------------
  ioremap on RAM at 0x3f251000 - 0x3fa1afff
  WARNING: CPU: 0 PID: 0 at arch/x86/mm/ioremap.c:166 __ioremap_caller ...
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.20.0 #48
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
  EIP: __ioremap_caller.constprop.0+0x249/0x260
  Code: 90 0f b7 05 4e 38 40 de 09 45 e0 e9 09 ff ff ff 90 8d 45 ec c6 05 ...
  EAX: 00000029 EBX: 00000000 ECX: de59c228 EDX: 00000001
  ESI: 3f250fff EDI: 00000000 EBP: de3edf20 ESP: de3edee0
  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00200296
  CR0: 80050033 CR2: ffd17000 CR3: 1e58c000 CR4: 00040690
  Call Trace:
   ioremap_cache+0xd/0x10
   ? old_map_region+0x72/0x9d
   old_map_region+0x72/0x9d
   efi_map_region+0x8/0xa
   efi_enter_virtual_mode+0x260/0x43b
   start_kernel+0x329/0x3aa
   i386_start_kernel+0xa7/0xab
   startup_32_smp+0x164/0x168
  ---[ end trace e15ccf6b9f356833 ]---

Let's work around this by disregarding the memory attributes table
altogether on i386, which does not result in a loss of functionality
or protection, given that we never consumed the contents.

Fixes: 3a6b6c6 ("efi: Make EFI_MEMORY_ATTRIBUTES_TABLE ... ")
Tested-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200304165917.5893-1-ardb@kernel.org
Link: https://lore.kernel.org/r/20200308080859.21568-21-ardb@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
frank-w pushed a commit that referenced this pull request May 9, 2020
…f fs_info::journal_info

commit fcc9973 upstream.

[BUG]
One run of btrfs/063 triggered the following lockdep warning:
  ============================================
  WARNING: possible recursive locking detected
  5.6.0-rc7-custom+ #48 Not tainted
  --------------------------------------------
  kworker/u24:0/7 is trying to acquire lock:
  ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]

  but task is already holding lock:
  ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]

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

         CPU0
         ----
    lock(sb_internal#2);
    lock(sb_internal#2);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  4 locks held by kworker/u24:0/7:
   #0: ffff88817b495948 ((wq_completion)btrfs-endio-write){+.+.}, at: process_one_work+0x557/0xb80
   #1: ffff888189ea7db8 ((work_completion)(&work->normal_work)){+.+.}, at: process_one_work+0x557/0xb80
   #2: ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
   #3: ffff888174ca4da8 (&fs_info->reloc_mutex){+.+.}, at: btrfs_record_root_in_trans+0x83/0xd0 [btrfs]

  stack backtrace:
  CPU: 0 PID: 7 Comm: kworker/u24:0 Not tainted 5.6.0-rc7-custom+ #48
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
  Call Trace:
   dump_stack+0xc2/0x11a
   __lock_acquire.cold+0xce/0x214
   lock_acquire+0xe6/0x210
   __sb_start_write+0x14e/0x290
   start_transaction+0x66c/0x890 [btrfs]
   btrfs_join_transaction+0x1d/0x20 [btrfs]
   find_free_extent+0x1504/0x1a50 [btrfs]
   btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
   btrfs_alloc_tree_block+0x1ac/0x570 [btrfs]
   btrfs_copy_root+0x213/0x580 [btrfs]
   create_reloc_root+0x3bd/0x470 [btrfs]
   btrfs_init_reloc_root+0x2d2/0x310 [btrfs]
   record_root_in_trans+0x191/0x1d0 [btrfs]
   btrfs_record_root_in_trans+0x90/0xd0 [btrfs]
   start_transaction+0x16e/0x890 [btrfs]
   btrfs_join_transaction+0x1d/0x20 [btrfs]
   btrfs_finish_ordered_io+0x55d/0xcd0 [btrfs]
   finish_ordered_fn+0x15/0x20 [btrfs]
   btrfs_work_helper+0x116/0x9a0 [btrfs]
   process_one_work+0x632/0xb80
   worker_thread+0x80/0x690
   kthread+0x1a3/0x1f0
   ret_from_fork+0x27/0x50

It's pretty hard to reproduce, only one hit so far.

[CAUSE]
This is because we're calling btrfs_join_transaction() without re-using
the current running one:

btrfs_finish_ordered_io()
|- btrfs_join_transaction()		<<< Call #1
   |- btrfs_record_root_in_trans()
      |- btrfs_reserve_extent()
	 |- btrfs_join_transaction()	<<< Call #2

Normally such btrfs_join_transaction() call should re-use the existing
one, without trying to re-start a transaction.

But the problem is, in btrfs_join_transaction() call #1, we call
btrfs_record_root_in_trans() before initializing current::journal_info.

And in btrfs_join_transaction() call #2, we're relying on
current::journal_info to avoid such deadlock.

[FIX]
Call btrfs_record_root_in_trans() after we have initialized
current::journal_info.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this pull request May 9, 2020
[ Upstream commit dd09fad ]

Commit:

  3a6b6c6 ("efi: Make EFI_MEMORY_ATTRIBUTES_TABLE initialization common across all architectures")

moved the call to efi_memattr_init() from ARM specific to the generic
EFI init code, in order to be able to apply the restricted permissions
described in that table on x86 as well.

We never enabled this feature fully on i386, and so mapping and
reserving this table is pointless. However, due to the early call to
memblock_reserve(), the memory bookkeeping gets confused to the point
where it produces the splat below when we try to map the memory later
on:

  ------------[ cut here ]------------
  ioremap on RAM at 0x3f251000 - 0x3fa1afff
  WARNING: CPU: 0 PID: 0 at arch/x86/mm/ioremap.c:166 __ioremap_caller ...
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.20.0 #48
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
  EIP: __ioremap_caller.constprop.0+0x249/0x260
  Code: 90 0f b7 05 4e 38 40 de 09 45 e0 e9 09 ff ff ff 90 8d 45 ec c6 05 ...
  EAX: 00000029 EBX: 00000000 ECX: de59c228 EDX: 00000001
  ESI: 3f250fff EDI: 00000000 EBP: de3edf20 ESP: de3edee0
  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00200296
  CR0: 80050033 CR2: ffd17000 CR3: 1e58c000 CR4: 00040690
  Call Trace:
   ioremap_cache+0xd/0x10
   ? old_map_region+0x72/0x9d
   old_map_region+0x72/0x9d
   efi_map_region+0x8/0xa
   efi_enter_virtual_mode+0x260/0x43b
   start_kernel+0x329/0x3aa
   i386_start_kernel+0xa7/0xab
   startup_32_smp+0x164/0x168
  ---[ end trace e15ccf6b9f356833 ]---

Let's work around this by disregarding the memory attributes table
altogether on i386, which does not result in a loss of functionality
or protection, given that we never consumed the contents.

Fixes: 3a6b6c6 ("efi: Make EFI_MEMORY_ATTRIBUTES_TABLE ... ")
Tested-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200304165917.5893-1-ardb@kernel.org
Link: https://lore.kernel.org/r/20200308080859.21568-21-ardb@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
frank-w pushed a commit that referenced this pull request May 9, 2020
…f fs_info::journal_info

commit fcc9973 upstream.

[BUG]
One run of btrfs/063 triggered the following lockdep warning:
  ============================================
  WARNING: possible recursive locking detected
  5.6.0-rc7-custom+ #48 Not tainted
  --------------------------------------------
  kworker/u24:0/7 is trying to acquire lock:
  ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]

  but task is already holding lock:
  ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]

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

         CPU0
         ----
    lock(sb_internal#2);
    lock(sb_internal#2);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  4 locks held by kworker/u24:0/7:
   #0: ffff88817b495948 ((wq_completion)btrfs-endio-write){+.+.}, at: process_one_work+0x557/0xb80
   #1: ffff888189ea7db8 ((work_completion)(&work->normal_work)){+.+.}, at: process_one_work+0x557/0xb80
   #2: ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
   #3: ffff888174ca4da8 (&fs_info->reloc_mutex){+.+.}, at: btrfs_record_root_in_trans+0x83/0xd0 [btrfs]

  stack backtrace:
  CPU: 0 PID: 7 Comm: kworker/u24:0 Not tainted 5.6.0-rc7-custom+ #48
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
  Call Trace:
   dump_stack+0xc2/0x11a
   __lock_acquire.cold+0xce/0x214
   lock_acquire+0xe6/0x210
   __sb_start_write+0x14e/0x290
   start_transaction+0x66c/0x890 [btrfs]
   btrfs_join_transaction+0x1d/0x20 [btrfs]
   find_free_extent+0x1504/0x1a50 [btrfs]
   btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
   btrfs_alloc_tree_block+0x1ac/0x570 [btrfs]
   btrfs_copy_root+0x213/0x580 [btrfs]
   create_reloc_root+0x3bd/0x470 [btrfs]
   btrfs_init_reloc_root+0x2d2/0x310 [btrfs]
   record_root_in_trans+0x191/0x1d0 [btrfs]
   btrfs_record_root_in_trans+0x90/0xd0 [btrfs]
   start_transaction+0x16e/0x890 [btrfs]
   btrfs_join_transaction+0x1d/0x20 [btrfs]
   btrfs_finish_ordered_io+0x55d/0xcd0 [btrfs]
   finish_ordered_fn+0x15/0x20 [btrfs]
   btrfs_work_helper+0x116/0x9a0 [btrfs]
   process_one_work+0x632/0xb80
   worker_thread+0x80/0x690
   kthread+0x1a3/0x1f0
   ret_from_fork+0x27/0x50

It's pretty hard to reproduce, only one hit so far.

[CAUSE]
This is because we're calling btrfs_join_transaction() without re-using
the current running one:

btrfs_finish_ordered_io()
|- btrfs_join_transaction()		<<< Call #1
   |- btrfs_record_root_in_trans()
      |- btrfs_reserve_extent()
	 |- btrfs_join_transaction()	<<< Call #2

Normally such btrfs_join_transaction() call should re-use the existing
one, without trying to re-start a transaction.

But the problem is, in btrfs_join_transaction() call #1, we call
btrfs_record_root_in_trans() before initializing current::journal_info.

And in btrfs_join_transaction() call #2, we're relying on
current::journal_info to avoid such deadlock.

[FIX]
Call btrfs_record_root_in_trans() after we have initialized
current::journal_info.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this pull request Jul 28, 2020
I got null-ptr-deref in serial8250_start_tx():

[   78.114630] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[   78.123778] Mem abort info:
[   78.126560]   ESR = 0x86000007
[   78.129603]   EC = 0x21: IABT (current EL), IL = 32 bits
[   78.134891]   SET = 0, FnV = 0
[   78.137933]   EA = 0, S1PTW = 0
[   78.141064] user pgtable: 64k pages, 48-bit VAs, pgdp=00000027d41a8600
[   78.147562] [0000000000000000] pgd=00000027893f0003, p4d=00000027893f0003, pud=00000027893f0003, pmd=00000027c9a20003, pte=0000000000000000
[   78.160029] Internal error: Oops: 86000007 [#1] SMP
[   78.164886] Modules linked in: sunrpc vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce ses enclosure sg sbsa_gwdt ipmi_ssif spi_dw_mmio sch_fq_codel vhost_net tun vhost vhost_iotlb tap ip_tables ext4 mbcache jbd2 ahci hisi_sas_v3_hw libahci hisi_sas_main libsas hns3 scsi_transport_sas hclge libata megaraid_sas ipmi_si hnae3 ipmi_devintf ipmi_msghandler br_netfilter bridge stp llc nvme nvme_core xt_sctp sctp libcrc32c dm_mod nbd
[   78.207383] CPU: 11 PID: 23258 Comm: null-ptr Not tainted 5.8.0-rc6+ #48
[   78.214056] Hardware name: Huawei TaiShan 2280 V2/BC82AMDC, BIOS 2280-V2 CS V3.B210.01 03/12/2020
[   78.222888] pstate: 80400089 (Nzcv daIf +PAN -UAO BTYPE=--)
[   78.228435] pc : 0x0
[   78.230618] lr : serial8250_start_tx+0x160/0x260
[   78.235215] sp : ffff800062eefb80
[   78.238517] x29: ffff800062eefb80 x28: 0000000000000fff
[   78.243807] x27: ffff800062eefd80 x26: ffff202fd83b3000
[   78.249098] x25: ffff800062eefd80 x24: ffff202fd83b3000
[   78.254388] x23: ffff002fc5e50be8 x22: 0000000000000002
[   78.259679] x21: 0000000000000001 x20: 0000000000000000
[   78.264969] x19: ffffa688827eecc8 x18: 0000000000000000
[   78.270259] x17: 0000000000000000 x16: 0000000000000000
[   78.275550] x15: ffffa68881bc67a8 x14: 00000000000002e6
[   78.280841] x13: ffffa68881bc67a8 x12: 000000000000c539
[   78.286131] x11: d37a6f4de9bd37a7 x10: ffffa68881cccff0
[   78.291421] x9 : ffffa68881bc6000 x8 : ffffa688819daa88
[   78.296711] x7 : ffffa688822a0f20 x6 : ffffa688819e0000
[   78.302002] x5 : ffff800062eef9d0 x4 : ffffa68881e707a8
[   78.307292] x3 : 0000000000000000 x2 : 0000000000000002
[   78.312582] x1 : 0000000000000001 x0 : ffffa688827eecc8
[   78.317873] Call trace:
[   78.320312]  0x0
[   78.322147]  __uart_start.isra.9+0x64/0x78
[   78.326229]  uart_start+0xb8/0x1c8
[   78.329620]  uart_flush_chars+0x24/0x30
[   78.333442]  n_tty_receive_buf_common+0x7b0/0xc30
[   78.338128]  n_tty_receive_buf+0x44/0x2c8
[   78.342122]  tty_ioctl+0x348/0x11f8
[   78.345599]  ksys_ioctl+0xd8/0xf8
[   78.348903]  __arm64_sys_ioctl+0x2c/0xc8
[   78.352812]  el0_svc_common.constprop.2+0x88/0x1b0
[   78.357583]  do_el0_svc+0x44/0xd0
[   78.360887]  el0_sync_handler+0x14c/0x1d0
[   78.364880]  el0_sync+0x140/0x180
[   78.368185] Code: bad PC value

SERIAL_PORT_DFNS is not defined on each arch, if it's not defined,
serial8250_set_defaults() won't be called in serial8250_isa_init_ports(),
so the p->serial_in pointer won't be initialized, and it leads a null-ptr-deref.
Fix this problem by calling serial8250_set_defaults() after init uart port.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200721143852.4058352-1-yangyingliang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this pull request Aug 7, 2020
commit f4c23a1 upstream.

I got null-ptr-deref in serial8250_start_tx():

[   78.114630] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[   78.123778] Mem abort info:
[   78.126560]   ESR = 0x86000007
[   78.129603]   EC = 0x21: IABT (current EL), IL = 32 bits
[   78.134891]   SET = 0, FnV = 0
[   78.137933]   EA = 0, S1PTW = 0
[   78.141064] user pgtable: 64k pages, 48-bit VAs, pgdp=00000027d41a8600
[   78.147562] [0000000000000000] pgd=00000027893f0003, p4d=00000027893f0003, pud=00000027893f0003, pmd=00000027c9a20003, pte=0000000000000000
[   78.160029] Internal error: Oops: 86000007 [#1] SMP
[   78.164886] Modules linked in: sunrpc vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce ses enclosure sg sbsa_gwdt ipmi_ssif spi_dw_mmio sch_fq_codel vhost_net tun vhost vhost_iotlb tap ip_tables ext4 mbcache jbd2 ahci hisi_sas_v3_hw libahci hisi_sas_main libsas hns3 scsi_transport_sas hclge libata megaraid_sas ipmi_si hnae3 ipmi_devintf ipmi_msghandler br_netfilter bridge stp llc nvme nvme_core xt_sctp sctp libcrc32c dm_mod nbd
[   78.207383] CPU: 11 PID: 23258 Comm: null-ptr Not tainted 5.8.0-rc6+ #48
[   78.214056] Hardware name: Huawei TaiShan 2280 V2/BC82AMDC, BIOS 2280-V2 CS V3.B210.01 03/12/2020
[   78.222888] pstate: 80400089 (Nzcv daIf +PAN -UAO BTYPE=--)
[   78.228435] pc : 0x0
[   78.230618] lr : serial8250_start_tx+0x160/0x260
[   78.235215] sp : ffff800062eefb80
[   78.238517] x29: ffff800062eefb80 x28: 0000000000000fff
[   78.243807] x27: ffff800062eefd80 x26: ffff202fd83b3000
[   78.249098] x25: ffff800062eefd80 x24: ffff202fd83b3000
[   78.254388] x23: ffff002fc5e50be8 x22: 0000000000000002
[   78.259679] x21: 0000000000000001 x20: 0000000000000000
[   78.264969] x19: ffffa688827eecc8 x18: 0000000000000000
[   78.270259] x17: 0000000000000000 x16: 0000000000000000
[   78.275550] x15: ffffa68881bc67a8 x14: 00000000000002e6
[   78.280841] x13: ffffa68881bc67a8 x12: 000000000000c539
[   78.286131] x11: d37a6f4de9bd37a7 x10: ffffa68881cccff0
[   78.291421] x9 : ffffa68881bc6000 x8 : ffffa688819daa88
[   78.296711] x7 : ffffa688822a0f20 x6 : ffffa688819e0000
[   78.302002] x5 : ffff800062eef9d0 x4 : ffffa68881e707a8
[   78.307292] x3 : 0000000000000000 x2 : 0000000000000002
[   78.312582] x1 : 0000000000000001 x0 : ffffa688827eecc8
[   78.317873] Call trace:
[   78.320312]  0x0
[   78.322147]  __uart_start.isra.9+0x64/0x78
[   78.326229]  uart_start+0xb8/0x1c8
[   78.329620]  uart_flush_chars+0x24/0x30
[   78.333442]  n_tty_receive_buf_common+0x7b0/0xc30
[   78.338128]  n_tty_receive_buf+0x44/0x2c8
[   78.342122]  tty_ioctl+0x348/0x11f8
[   78.345599]  ksys_ioctl+0xd8/0xf8
[   78.348903]  __arm64_sys_ioctl+0x2c/0xc8
[   78.352812]  el0_svc_common.constprop.2+0x88/0x1b0
[   78.357583]  do_el0_svc+0x44/0xd0
[   78.360887]  el0_sync_handler+0x14c/0x1d0
[   78.364880]  el0_sync+0x140/0x180
[   78.368185] Code: bad PC value

SERIAL_PORT_DFNS is not defined on each arch, if it's not defined,
serial8250_set_defaults() won't be called in serial8250_isa_init_ports(),
so the p->serial_in pointer won't be initialized, and it leads a null-ptr-deref.
Fix this problem by calling serial8250_set_defaults() after init uart port.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200721143852.4058352-1-yangyingliang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this pull request Aug 7, 2020
commit f4c23a1 upstream.

I got null-ptr-deref in serial8250_start_tx():

[   78.114630] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[   78.123778] Mem abort info:
[   78.126560]   ESR = 0x86000007
[   78.129603]   EC = 0x21: IABT (current EL), IL = 32 bits
[   78.134891]   SET = 0, FnV = 0
[   78.137933]   EA = 0, S1PTW = 0
[   78.141064] user pgtable: 64k pages, 48-bit VAs, pgdp=00000027d41a8600
[   78.147562] [0000000000000000] pgd=00000027893f0003, p4d=00000027893f0003, pud=00000027893f0003, pmd=00000027c9a20003, pte=0000000000000000
[   78.160029] Internal error: Oops: 86000007 [#1] SMP
[   78.164886] Modules linked in: sunrpc vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce ses enclosure sg sbsa_gwdt ipmi_ssif spi_dw_mmio sch_fq_codel vhost_net tun vhost vhost_iotlb tap ip_tables ext4 mbcache jbd2 ahci hisi_sas_v3_hw libahci hisi_sas_main libsas hns3 scsi_transport_sas hclge libata megaraid_sas ipmi_si hnae3 ipmi_devintf ipmi_msghandler br_netfilter bridge stp llc nvme nvme_core xt_sctp sctp libcrc32c dm_mod nbd
[   78.207383] CPU: 11 PID: 23258 Comm: null-ptr Not tainted 5.8.0-rc6+ #48
[   78.214056] Hardware name: Huawei TaiShan 2280 V2/BC82AMDC, BIOS 2280-V2 CS V3.B210.01 03/12/2020
[   78.222888] pstate: 80400089 (Nzcv daIf +PAN -UAO BTYPE=--)
[   78.228435] pc : 0x0
[   78.230618] lr : serial8250_start_tx+0x160/0x260
[   78.235215] sp : ffff800062eefb80
[   78.238517] x29: ffff800062eefb80 x28: 0000000000000fff
[   78.243807] x27: ffff800062eefd80 x26: ffff202fd83b3000
[   78.249098] x25: ffff800062eefd80 x24: ffff202fd83b3000
[   78.254388] x23: ffff002fc5e50be8 x22: 0000000000000002
[   78.259679] x21: 0000000000000001 x20: 0000000000000000
[   78.264969] x19: ffffa688827eecc8 x18: 0000000000000000
[   78.270259] x17: 0000000000000000 x16: 0000000000000000
[   78.275550] x15: ffffa68881bc67a8 x14: 00000000000002e6
[   78.280841] x13: ffffa68881bc67a8 x12: 000000000000c539
[   78.286131] x11: d37a6f4de9bd37a7 x10: ffffa68881cccff0
[   78.291421] x9 : ffffa68881bc6000 x8 : ffffa688819daa88
[   78.296711] x7 : ffffa688822a0f20 x6 : ffffa688819e0000
[   78.302002] x5 : ffff800062eef9d0 x4 : ffffa68881e707a8
[   78.307292] x3 : 0000000000000000 x2 : 0000000000000002
[   78.312582] x1 : 0000000000000001 x0 : ffffa688827eecc8
[   78.317873] Call trace:
[   78.320312]  0x0
[   78.322147]  __uart_start.isra.9+0x64/0x78
[   78.326229]  uart_start+0xb8/0x1c8
[   78.329620]  uart_flush_chars+0x24/0x30
[   78.333442]  n_tty_receive_buf_common+0x7b0/0xc30
[   78.338128]  n_tty_receive_buf+0x44/0x2c8
[   78.342122]  tty_ioctl+0x348/0x11f8
[   78.345599]  ksys_ioctl+0xd8/0xf8
[   78.348903]  __arm64_sys_ioctl+0x2c/0xc8
[   78.352812]  el0_svc_common.constprop.2+0x88/0x1b0
[   78.357583]  do_el0_svc+0x44/0xd0
[   78.360887]  el0_sync_handler+0x14c/0x1d0
[   78.364880]  el0_sync+0x140/0x180
[   78.368185] Code: bad PC value

SERIAL_PORT_DFNS is not defined on each arch, if it's not defined,
serial8250_set_defaults() won't be called in serial8250_isa_init_ports(),
so the p->serial_in pointer won't be initialized, and it leads a null-ptr-deref.
Fix this problem by calling serial8250_set_defaults() after init uart port.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200721143852.4058352-1-yangyingliang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this pull request May 19, 2021
[ Upstream commit 0f20615 ]

Fix BPF_CORE_READ_BITFIELD() macro used for reading CO-RE-relocatable
bitfields. Missing breaks in a switch caused 8-byte reads always. This can
confuse libbpf because it does strict checks that memory load size corresponds
to the original size of the field, which in this case quite often would be
wrong.

After fixing that, we run into another problem, which quite subtle, so worth
documenting here. The issue is in Clang optimization and CO-RE relocation
interactions. Without that asm volatile construct (also known as
barrier_var()), Clang will re-order BYTE_OFFSET and BYTE_SIZE relocations and
will apply BYTE_OFFSET 4 times for each switch case arm. This will result in
the same error from libbpf about mismatch of memory load size and original
field size. I.e., if we were reading u32, we'd still have *(u8 *), *(u16 *),
*(u32 *), and *(u64 *) memory loads, three of which will fail. Using
barrier_var() forces Clang to apply BYTE_OFFSET relocation first (and once) to
calculate p, after which value of p is used without relocation in each of
switch case arms, doing appropiately-sized memory load.

Here's the list of relevant relocations and pieces of generated BPF code
before and after this patch for test_core_reloc_bitfields_direct selftests.

BEFORE
=====
 #45: core_reloc: insn #160 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32
 #46: core_reloc: insn #167 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 #47: core_reloc: insn #174 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 #48: core_reloc: insn #178 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 #49: core_reloc: insn #182 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32

     157:       18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll
     159:       7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1
     160:       b7 02 00 00 04 00 00 00 r2 = 4
; BYTE_SIZE relocation here                 ^^^
     161:       66 02 07 00 03 00 00 00 if w2 s> 3 goto +7 <LBB0_63>
     162:       16 02 0d 00 01 00 00 00 if w2 == 1 goto +13 <LBB0_65>
     163:       16 02 01 00 02 00 00 00 if w2 == 2 goto +1 <LBB0_66>
     164:       05 00 12 00 00 00 00 00 goto +18 <LBB0_69>

0000000000000528 <LBB0_66>:
     165:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     167:       69 11 08 00 00 00 00 00 r1 = *(u16 *)(r1 + 8)
; BYTE_OFFSET relo here w/ WRONG size        ^^^^^^^^^^^^^^^^
     168:       05 00 0e 00 00 00 00 00 goto +14 <LBB0_69>

0000000000000548 <LBB0_63>:
     169:       16 02 0a 00 04 00 00 00 if w2 == 4 goto +10 <LBB0_67>
     170:       16 02 01 00 08 00 00 00 if w2 == 8 goto +1 <LBB0_68>
     171:       05 00 0b 00 00 00 00 00 goto +11 <LBB0_69>

0000000000000560 <LBB0_68>:
     172:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     174:       79 11 08 00 00 00 00 00 r1 = *(u64 *)(r1 + 8)
; BYTE_OFFSET relo here w/ WRONG size        ^^^^^^^^^^^^^^^^
     175:       05 00 07 00 00 00 00 00 goto +7 <LBB0_69>

0000000000000580 <LBB0_65>:
     176:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     178:       71 11 08 00 00 00 00 00 r1 = *(u8 *)(r1 + 8)
; BYTE_OFFSET relo here w/ WRONG size        ^^^^^^^^^^^^^^^^
     179:       05 00 03 00 00 00 00 00 goto +3 <LBB0_69>

00000000000005a0 <LBB0_67>:
     180:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     182:       61 11 08 00 00 00 00 00 r1 = *(u32 *)(r1 + 8)
; BYTE_OFFSET relo here w/ RIGHT size        ^^^^^^^^^^^^^^^^

00000000000005b8 <LBB0_69>:
     183:       67 01 00 00 20 00 00 00 r1 <<= 32
     184:       b7 02 00 00 00 00 00 00 r2 = 0
     185:       16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71>
     186:       c7 01 00 00 20 00 00 00 r1 s>>= 32
     187:       05 00 01 00 00 00 00 00 goto +1 <LBB0_72>

00000000000005e0 <LBB0_71>:
     188:       77 01 00 00 20 00 00 00 r1 >>= 32

AFTER
=====

 #30: core_reloc: insn #132 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 #31: core_reloc: insn #134 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32

     129:       18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll
     131:       7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1
     132:       b7 01 00 00 08 00 00 00 r1 = 8
; BYTE_OFFSET relo here                     ^^^
; no size check for non-memory dereferencing instructions
     133:       0f 12 00 00 00 00 00 00 r2 += r1
     134:       b7 03 00 00 04 00 00 00 r3 = 4
; BYTE_SIZE relocation here                 ^^^
     135:       66 03 05 00 03 00 00 00 if w3 s> 3 goto +5 <LBB0_63>
     136:       16 03 09 00 01 00 00 00 if w3 == 1 goto +9 <LBB0_65>
     137:       16 03 01 00 02 00 00 00 if w3 == 2 goto +1 <LBB0_66>
     138:       05 00 0a 00 00 00 00 00 goto +10 <LBB0_69>

0000000000000458 <LBB0_66>:
     139:       69 21 00 00 00 00 00 00 r1 = *(u16 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^
     140:       05 00 08 00 00 00 00 00 goto +8 <LBB0_69>

0000000000000468 <LBB0_63>:
     141:       16 03 06 00 04 00 00 00 if w3 == 4 goto +6 <LBB0_67>
     142:       16 03 01 00 08 00 00 00 if w3 == 8 goto +1 <LBB0_68>
     143:       05 00 05 00 00 00 00 00 goto +5 <LBB0_69>

0000000000000480 <LBB0_68>:
     144:       79 21 00 00 00 00 00 00 r1 = *(u64 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^
     145:       05 00 03 00 00 00 00 00 goto +3 <LBB0_69>

0000000000000490 <LBB0_65>:
     146:       71 21 00 00 00 00 00 00 r1 = *(u8 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^
     147:       05 00 01 00 00 00 00 00 goto +1 <LBB0_69>

00000000000004a0 <LBB0_67>:
     148:       61 21 00 00 00 00 00 00 r1 = *(u32 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^

00000000000004a8 <LBB0_69>:
     149:       67 01 00 00 20 00 00 00 r1 <<= 32
     150:       b7 02 00 00 00 00 00 00 r2 = 0
     151:       16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71>
     152:       c7 01 00 00 20 00 00 00 r1 s>>= 32
     153:       05 00 01 00 00 00 00 00 goto +1 <LBB0_72>

00000000000004d0 <LBB0_71>:
     154:       77 01 00 00 20 00 00 00 r1 >>= 323

Fixes: ee26dad ("libbpf: Add support for relocatable bitfields")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Lorenz Bauer <lmb@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210426192949.416837-4-andrii@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
frank-w pushed a commit that referenced this pull request Jun 3, 2021
[ Upstream commit d5027ca ]

Ritesh reported a bug [1] against UML, noting that it crashed on
startup. The backtrace shows the following (heavily redacted):

(gdb) bt
...
 #26 0x0000000060015b5d in sem_init () at ipc/sem.c:268
 #27 0x00007f89906d92f7 in ?? () from /lib/x86_64-linux-gnu/libcom_err.so.2
 #28 0x00007f8990ab8fb2 in call_init (...) at dl-init.c:72
...
 #40 0x00007f89909bf3a6 in nss_load_library (...) at nsswitch.c:359
...
 #44 0x00007f8990895e35 in _nss_compat_getgrnam_r (...) at nss_compat/compat-grp.c:486
 #45 0x00007f8990968b85 in __getgrnam_r [...]
 #46 0x00007f89909d6b77 in grantpt [...]
 #47 0x00007f8990a9394e in __GI_openpty [...]
 #48 0x00000000604a1f65 in openpty_cb (...) at arch/um/os-Linux/sigio.c:407
 #49 0x00000000604a58d0 in start_idle_thread (...) at arch/um/os-Linux/skas/process.c:598
 #50 0x0000000060004a3d in start_uml () at arch/um/kernel/skas/process.c:45
 #51 0x00000000600047b2 in linux_main (...) at arch/um/kernel/um_arch.c:334
 #52 0x000000006000574f in main (...) at arch/um/os-Linux/main.c:144

indicating that the UML function openpty_cb() calls openpty(),
which internally calls __getgrnam_r(), which causes the nsswitch
machinery to get started.

This loads, through lots of indirection that I snipped, the
libcom_err.so.2 library, which (in an unknown function, "??")
calls sem_init().

Now, of course it wants to get libpthread's sem_init(), since
it's linked against libpthread. However, the dynamic linker
looks up that symbol against the binary first, and gets the
kernel's sem_init().

Hajime Tazaki noted that "objcopy -L" can localize a symbol,
so the dynamic linker wouldn't do the lookup this way. I tried,
but for some reason that didn't seem to work.

Doing the same thing in the linker script instead does seem to
work, though I cannot entirely explain - it *also* works if I
just add "VERSION { { global: *; }; }" instead, indicating that
something else is happening that I don't really understand. It
may be that explicitly doing that marks them with some kind of
empty version, and that's different from the default.

Explicitly marking them with a version breaks kallsyms, so that
doesn't seem to be possible.

Marking all the symbols as local seems correct, and does seem
to address the issue, so do that. Also do it for static link,
nsswitch libraries could still be loaded there.

[1] https://bugs.debian.org/983379

Reported-by: Ritesh Raj Sarraf <rrs@debian.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Tested-By: Ritesh Raj Sarraf <rrs@debian.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
frank-w pushed a commit that referenced this pull request Jun 3, 2021
[ Upstream commit d5027ca ]

Ritesh reported a bug [1] against UML, noting that it crashed on
startup. The backtrace shows the following (heavily redacted):

(gdb) bt
...
 #26 0x0000000060015b5d in sem_init () at ipc/sem.c:268
 #27 0x00007f89906d92f7 in ?? () from /lib/x86_64-linux-gnu/libcom_err.so.2
 #28 0x00007f8990ab8fb2 in call_init (...) at dl-init.c:72
...
 #40 0x00007f89909bf3a6 in nss_load_library (...) at nsswitch.c:359
...
 #44 0x00007f8990895e35 in _nss_compat_getgrnam_r (...) at nss_compat/compat-grp.c:486
 #45 0x00007f8990968b85 in __getgrnam_r [...]
 #46 0x00007f89909d6b77 in grantpt [...]
 #47 0x00007f8990a9394e in __GI_openpty [...]
 #48 0x00000000604a1f65 in openpty_cb (...) at arch/um/os-Linux/sigio.c:407
 #49 0x00000000604a58d0 in start_idle_thread (...) at arch/um/os-Linux/skas/process.c:598
 #50 0x0000000060004a3d in start_uml () at arch/um/kernel/skas/process.c:45
 #51 0x00000000600047b2 in linux_main (...) at arch/um/kernel/um_arch.c:334
 #52 0x000000006000574f in main (...) at arch/um/os-Linux/main.c:144

indicating that the UML function openpty_cb() calls openpty(),
which internally calls __getgrnam_r(), which causes the nsswitch
machinery to get started.

This loads, through lots of indirection that I snipped, the
libcom_err.so.2 library, which (in an unknown function, "??")
calls sem_init().

Now, of course it wants to get libpthread's sem_init(), since
it's linked against libpthread. However, the dynamic linker
looks up that symbol against the binary first, and gets the
kernel's sem_init().

Hajime Tazaki noted that "objcopy -L" can localize a symbol,
so the dynamic linker wouldn't do the lookup this way. I tried,
but for some reason that didn't seem to work.

Doing the same thing in the linker script instead does seem to
work, though I cannot entirely explain - it *also* works if I
just add "VERSION { { global: *; }; }" instead, indicating that
something else is happening that I don't really understand. It
may be that explicitly doing that marks them with some kind of
empty version, and that's different from the default.

Explicitly marking them with a version breaks kallsyms, so that
doesn't seem to be possible.

Marking all the symbols as local seems correct, and does seem
to address the issue, so do that. Also do it for static link,
nsswitch libraries could still be loaded there.

[1] https://bugs.debian.org/983379

Reported-by: Ritesh Raj Sarraf <rrs@debian.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Tested-By: Ritesh Raj Sarraf <rrs@debian.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
frank-w pushed a commit that referenced this pull request Jun 3, 2021
[ Upstream commit d5027ca ]

Ritesh reported a bug [1] against UML, noting that it crashed on
startup. The backtrace shows the following (heavily redacted):

(gdb) bt
...
 #26 0x0000000060015b5d in sem_init () at ipc/sem.c:268
 #27 0x00007f89906d92f7 in ?? () from /lib/x86_64-linux-gnu/libcom_err.so.2
 #28 0x00007f8990ab8fb2 in call_init (...) at dl-init.c:72
...
 #40 0x00007f89909bf3a6 in nss_load_library (...) at nsswitch.c:359
...
 #44 0x00007f8990895e35 in _nss_compat_getgrnam_r (...) at nss_compat/compat-grp.c:486
 #45 0x00007f8990968b85 in __getgrnam_r [...]
 #46 0x00007f89909d6b77 in grantpt [...]
 #47 0x00007f8990a9394e in __GI_openpty [...]
 #48 0x00000000604a1f65 in openpty_cb (...) at arch/um/os-Linux/sigio.c:407
 #49 0x00000000604a58d0 in start_idle_thread (...) at arch/um/os-Linux/skas/process.c:598
 #50 0x0000000060004a3d in start_uml () at arch/um/kernel/skas/process.c:45
 #51 0x00000000600047b2 in linux_main (...) at arch/um/kernel/um_arch.c:334
 #52 0x000000006000574f in main (...) at arch/um/os-Linux/main.c:144

indicating that the UML function openpty_cb() calls openpty(),
which internally calls __getgrnam_r(), which causes the nsswitch
machinery to get started.

This loads, through lots of indirection that I snipped, the
libcom_err.so.2 library, which (in an unknown function, "??")
calls sem_init().

Now, of course it wants to get libpthread's sem_init(), since
it's linked against libpthread. However, the dynamic linker
looks up that symbol against the binary first, and gets the
kernel's sem_init().

Hajime Tazaki noted that "objcopy -L" can localize a symbol,
so the dynamic linker wouldn't do the lookup this way. I tried,
but for some reason that didn't seem to work.

Doing the same thing in the linker script instead does seem to
work, though I cannot entirely explain - it *also* works if I
just add "VERSION { { global: *; }; }" instead, indicating that
something else is happening that I don't really understand. It
may be that explicitly doing that marks them with some kind of
empty version, and that's different from the default.

Explicitly marking them with a version breaks kallsyms, so that
doesn't seem to be possible.

Marking all the symbols as local seems correct, and does seem
to address the issue, so do that. Also do it for static link,
nsswitch libraries could still be loaded there.

[1] https://bugs.debian.org/983379

Reported-by: Ritesh Raj Sarraf <rrs@debian.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Tested-By: Ritesh Raj Sarraf <rrs@debian.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
frank-w pushed a commit that referenced this pull request Jun 3, 2021
[ Upstream commit d5027ca ]

Ritesh reported a bug [1] against UML, noting that it crashed on
startup. The backtrace shows the following (heavily redacted):

(gdb) bt
...
 #26 0x0000000060015b5d in sem_init () at ipc/sem.c:268
 #27 0x00007f89906d92f7 in ?? () from /lib/x86_64-linux-gnu/libcom_err.so.2
 #28 0x00007f8990ab8fb2 in call_init (...) at dl-init.c:72
...
 #40 0x00007f89909bf3a6 in nss_load_library (...) at nsswitch.c:359
...
 #44 0x00007f8990895e35 in _nss_compat_getgrnam_r (...) at nss_compat/compat-grp.c:486
 #45 0x00007f8990968b85 in __getgrnam_r [...]
 #46 0x00007f89909d6b77 in grantpt [...]
 #47 0x00007f8990a9394e in __GI_openpty [...]
 #48 0x00000000604a1f65 in openpty_cb (...) at arch/um/os-Linux/sigio.c:407
 #49 0x00000000604a58d0 in start_idle_thread (...) at arch/um/os-Linux/skas/process.c:598
 #50 0x0000000060004a3d in start_uml () at arch/um/kernel/skas/process.c:45
 #51 0x00000000600047b2 in linux_main (...) at arch/um/kernel/um_arch.c:334
 #52 0x000000006000574f in main (...) at arch/um/os-Linux/main.c:144

indicating that the UML function openpty_cb() calls openpty(),
which internally calls __getgrnam_r(), which causes the nsswitch
machinery to get started.

This loads, through lots of indirection that I snipped, the
libcom_err.so.2 library, which (in an unknown function, "??")
calls sem_init().

Now, of course it wants to get libpthread's sem_init(), since
it's linked against libpthread. However, the dynamic linker
looks up that symbol against the binary first, and gets the
kernel's sem_init().

Hajime Tazaki noted that "objcopy -L" can localize a symbol,
so the dynamic linker wouldn't do the lookup this way. I tried,
but for some reason that didn't seem to work.

Doing the same thing in the linker script instead does seem to
work, though I cannot entirely explain - it *also* works if I
just add "VERSION { { global: *; }; }" instead, indicating that
something else is happening that I don't really understand. It
may be that explicitly doing that marks them with some kind of
empty version, and that's different from the default.

Explicitly marking them with a version breaks kallsyms, so that
doesn't seem to be possible.

Marking all the symbols as local seems correct, and does seem
to address the issue, so do that. Also do it for static link,
nsswitch libraries could still be loaded there.

[1] https://bugs.debian.org/983379

Reported-by: Ritesh Raj Sarraf <rrs@debian.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Tested-By: Ritesh Raj Sarraf <rrs@debian.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
frank-w pushed a commit that referenced this pull request Jun 24, 2021
nft_set_elem_expr_alloc() needs an initialized set if expression sets on
the NFT_EXPR_GC flag. Move set fields initialization before expression
setup.

[4512935.019450] ==================================================================
[4512935.019456] BUG: KASAN: null-ptr-deref in nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
[4512935.019487] Read of size 8 at addr 0000000000000070 by task nft/23532
[4512935.019494] CPU: 1 PID: 23532 Comm: nft Not tainted 5.12.0-rc4+ #48
[...]
[4512935.019502] Call Trace:
[4512935.019505]  dump_stack+0x89/0xb4
[4512935.019512]  ? nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
[4512935.019536]  ? nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
[4512935.019560]  kasan_report.cold.12+0x5f/0xd8
[4512935.019566]  ? nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
[4512935.019590]  nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
[4512935.019615]  nf_tables_newset+0xc7f/0x1460 [nf_tables]

Reported-by: syzbot+ce96ca2b1d0b37c6422d@syzkaller.appspotmail.com
Fixes: 6503842 ("netfilter: nf_tables: allow to specify stateful expression in set definition")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
frank-w pushed a commit that referenced this pull request Sep 12, 2021
commit ad9f151 upstream.

nft_set_elem_expr_alloc() needs an initialized set if expression sets on
the NFT_EXPR_GC flag. Move set fields initialization before expression
setup.

[4512935.019450] ==================================================================
[4512935.019456] BUG: KASAN: null-ptr-deref in nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
[4512935.019487] Read of size 8 at addr 0000000000000070 by task nft/23532
[4512935.019494] CPU: 1 PID: 23532 Comm: nft Not tainted 5.12.0-rc4+ #48
[...]
[4512935.019502] Call Trace:
[4512935.019505]  dump_stack+0x89/0xb4
[4512935.019512]  ? nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
[4512935.019536]  ? nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
[4512935.019560]  kasan_report.cold.12+0x5f/0xd8
[4512935.019566]  ? nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
[4512935.019590]  nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
[4512935.019615]  nf_tables_newset+0xc7f/0x1460 [nf_tables]

Reported-by: syzbot+ce96ca2b1d0b37c6422d@syzkaller.appspotmail.com
Fixes: 6503842 ("netfilter: nf_tables: allow to specify stateful expression in set definition")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w pushed a commit that referenced this pull request Feb 18, 2022
syzbot detected a case where the page table counters were not properly
updated.

  syzkaller login:  ------------[ cut here ]------------
  kernel BUG at mm/page_table_check.c:162!
  invalid opcode: 0000 [#1] PREEMPT SMP KASAN
  CPU: 0 PID: 3099 Comm: pasha Not tainted 5.16.0+ #48
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIO4
  RIP: 0010:__page_table_check_zero+0x159/0x1a0
  Call Trace:
   free_pcp_prepare+0x3be/0xaa0
   free_unref_page+0x1c/0x650
   free_compound_page+0xec/0x130
   free_transhuge_page+0x1be/0x260
   __put_compound_page+0x90/0xd0
   release_pages+0x54c/0x1060
   __pagevec_release+0x7c/0x110
   shmem_undo_range+0x85e/0x1250
  ...

The repro involved having a huge page that is split due to uprobe event
temporarily replacing one of the pages in the huge page.  Later the huge
page was combined again, but the counters were off, as the PTE level was
not properly updated.

Make sure that when PMD is cleared and prior to freeing the level the
PTEs are updated.

Link: https://lkml.kernel.org/r/20220131203249.2832273-5-pasha.tatashin@soleen.com
Fixes: df4e817 ("mm: page table check")
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Paul Turner <pjt@google.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
frank-w pushed a commit that referenced this pull request Sep 9, 2023
Occasionally, with './test_progs -j' on my vm, I will hit the
following failure:

  test_cgrp_local_storage:PASS:join_cgroup /cgrp_local_storage 0 nsec
  test_cgroup_iter_sleepable:PASS:skel_open 0 nsec
  test_cgroup_iter_sleepable:PASS:skel_load 0 nsec
  test_cgroup_iter_sleepable:PASS:attach_iter 0 nsec
  test_cgroup_iter_sleepable:PASS:iter_create 0 nsec
  test_cgroup_iter_sleepable:FAIL:cgroup_id unexpected cgroup_id: actual 1 != expected 2812
  #48/5    cgrp_local_storage/cgroup_iter_sleepable:FAIL
  #48      cgrp_local_storage:FAIL

Finally, I decided to do some investigation since the test is introduced
by myself. It turns out the reason is due to cgroup_fd with value 0.
In cgroup_iter, a cgroup_fd of value 0 means the root cgroup.

	/* from cgroup_iter.c */
        if (fd)
                cgrp = cgroup_v1v2_get_from_fd(fd);
        else if (id)
                cgrp = cgroup_get_from_id(id);
        else /* walk the entire hierarchy by default. */
                cgrp = cgroup_get_from_path("/");

That is why we got cgroup_id 1 instead of expected 2812.

Why we got a cgroup_fd 0? Nobody should really touch 'stdin' (fd 0) in
test_progs. I traced 'close' syscall with stack trace and found the root
cause, which is a bug in bpf_obj_pinning.c. Basically, the code closed
fd 0 although it should not. Fixing the bug in bpf_obj_pinning.c also
resolved the above cgroup_iter_sleepable subtest failure.

Fixes: 3b22f98 ("selftests/bpf: Add path_fd-based BPF_OBJ_PIN and BPF_OBJ_GET tests")
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230827150551.1743497-1-yonghong.song@linux.dev
frank-w pushed a commit that referenced this pull request Jan 14, 2024
[ Upstream commit fe57575 ]

The `cgrp_local_storage` test triggers a kernel panic like:

  # ./test_progs -t cgrp_local_storage
  Can't find bpf_testmod.ko kernel module: -2
  WARNING! Selftests relying on bpf_testmod.ko will be skipped.
  [  550.930632] CPU 1 Unable to handle kernel paging request at virtual address 0000000000000080, era == ffff80000200be34, ra == ffff80000200be00
  [  550.931781] Oops[#1]:
  [  550.931966] CPU: 1 PID: 1303 Comm: test_progs Not tainted 6.7.0-rc2-loong-devel-g2f56bb0d2327 #35 a896aca3f4164f09cc346f89f2e09832e07be5f6
  [  550.932215] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  550.932403] pc ffff80000200be34 ra ffff80000200be00 tp 9000000108350000 sp 9000000108353dc0
  [  550.932545] a0 0000000000000000 a1 0000000000000517 a2 0000000000000118 a3 00007ffffbb15558
  [  550.932682] a4 00007ffffbb15620 a5 90000001004e7700 a6 0000000000000021 a7 0000000000000118
  [  550.932824] t0 ffff80000200bdc0 t1 0000000000000517 t2 0000000000000517 t3 00007ffff1c06ee0
  [  550.932961] t4 0000555578ae04d0 t5 fffffffffffffff8 t6 0000000000000004 t7 0000000000000020
  [  550.933097] t8 0000000000000040 u0 00000000000007b8 s9 9000000108353e00 s0 90000001004e7700
  [  550.933241] s1 9000000004005000 s2 0000000000000001 s3 0000000000000000 s4 0000555555eb2ec8
  [  550.933379] s5 00007ffffbb15bb8 s6 00007ffff1dafd60 s7 000055555663f610 s8 00007ffff1db0050
  [  550.933520]    ra: ffff80000200be00 bpf_prog_98f1b9e767be2a84_on_enter+0x40/0x200
  [  550.933911]   ERA: ffff80000200be34 bpf_prog_98f1b9e767be2a84_on_enter+0x74/0x200
  [  550.934105]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  550.934596]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  550.934712]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  550.934836]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  550.934976] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  550.935097]  BADV: 0000000000000080
  [  550.935181]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  550.935291] Modules linked in:
  [  550.935391] Process test_progs (pid: 1303, threadinfo=000000006c3b1c41, task=0000000061f84a55)
  [  550.935643] Stack : 00007ffffbb15bb8 0000555555eb2ec8 0000000000000000 0000000000000001
  [  550.935844]         9000000004005000 ffff80001b864000 00007ffffbb15450 90000000029aa034
  [  550.935990]         0000000000000000 9000000108353ec0 0000000000000118 d07d9dfb09721a09
  [  550.936175]         0000000000000001 0000000000000000 9000000108353ec0 0000000000000118
  [  550.936314]         9000000101d46ad0 900000000290abf0 000055555663f610 0000000000000000
  [  550.936479]         0000000000000003 9000000108353ec0 00007ffffbb15450 90000000029d7288
  [  550.936635]         00007ffff1dafd60 000055555663f610 0000000000000000 0000000000000003
  [  550.936779]         9000000108353ec0 90000000035dd1f0 00007ffff1dafd58 9000000002841c5c
  [  550.936939]         0000000000000119 0000555555eea5a8 00007ffff1d78780 00007ffffbb153e0
  [  550.937083]         ffffffffffffffda 00007ffffbb15518 0000000000000040 00007ffffbb15558
  [  550.937224]         ...
  [  550.937299] Call Trace:
  [  550.937521] [<ffff80000200be34>] bpf_prog_98f1b9e767be2a84_on_enter+0x74/0x200
  [  550.937910] [<90000000029aa034>] bpf_trace_run2+0x90/0x154
  [  550.938105] [<900000000290abf0>] syscall_trace_enter.isra.0+0x1cc/0x200
  [  550.938224] [<90000000035dd1f0>] do_syscall+0x48/0x94
  [  550.938319] [<9000000002841c5c>] handle_syscall+0xbc/0x158
  [  550.938477]
  [  550.938607] Code: 580009ae  50016000  262402e4 <28c20085> 14092084  03a00084  16000024  03240084  00150006
  [  550.938851]
  [  550.939021] ---[ end trace 0000000000000000 ]---

Further investigation shows that this panic is triggered by memory
load operations:

  ptr = bpf_cgrp_storage_get(&map_a, task->cgroups->dfl_cgrp, 0,
                             BPF_LOCAL_STORAGE_GET_F_CREATE);

The expression `task->cgroups->dfl_cgrp` involves two memory load.
Since the field offset fits in imm12 or imm14, we use ldd or ldptrd
instructions. But both instructions have the side effect that it will
signed-extended the imm operand. Finally, we got the wrong addresses
and panics is inevitable.

Use a generic ldxd instruction to avoid this kind of issues.

With this change, we have:

  # ./test_progs -t cgrp_local_storage
  Can't find bpf_testmod.ko kernel module: -2
  WARNING! Selftests relying on bpf_testmod.ko will be skipped.
  test_cgrp_local_storage:PASS:join_cgroup /cgrp_local_storage 0 nsec
  #48/1    cgrp_local_storage/tp_btf:OK
  test_attach_cgroup:PASS:skel_open 0 nsec
  test_attach_cgroup:PASS:prog_attach 0 nsec
  test_attach_cgroup:PASS:prog_attach 0 nsec
  libbpf: prog 'update_cookie_tracing': failed to attach: ERROR: strerror_r(-524)=22
  test_attach_cgroup:FAIL:prog_attach unexpected error: -524
  #48/2    cgrp_local_storage/attach_cgroup:FAIL
  test_recursion:PASS:skel_open_and_load 0 nsec
  libbpf: prog 'on_lookup': failed to attach: ERROR: strerror_r(-524)=22
  libbpf: prog 'on_lookup': failed to auto-attach: -524
  test_recursion:FAIL:skel_attach unexpected error: -524 (errno 524)
  #48/3    cgrp_local_storage/recursion:FAIL
  #48/4    cgrp_local_storage/negative:OK
  #48/5    cgrp_local_storage/cgroup_iter_sleepable:OK
  test_yes_rcu_lock:PASS:skel_open 0 nsec
  test_yes_rcu_lock:PASS:skel_load 0 nsec
  libbpf: prog 'yes_rcu_lock': failed to attach: ERROR: strerror_r(-524)=22
  libbpf: prog 'yes_rcu_lock': failed to auto-attach: -524
  test_yes_rcu_lock:FAIL:skel_attach unexpected error: -524 (errno 524)
  #48/6    cgrp_local_storage/yes_rcu_lock:FAIL
  #48/7    cgrp_local_storage/no_rcu_lock:OK
  #48      cgrp_local_storage:FAIL

  All error logs:
  test_cgrp_local_storage:PASS:join_cgroup /cgrp_local_storage 0 nsec
  test_attach_cgroup:PASS:skel_open 0 nsec
  test_attach_cgroup:PASS:prog_attach 0 nsec
  test_attach_cgroup:PASS:prog_attach 0 nsec
  libbpf: prog 'update_cookie_tracing': failed to attach: ERROR: strerror_r(-524)=22
  test_attach_cgroup:FAIL:prog_attach unexpected error: -524
  #48/2    cgrp_local_storage/attach_cgroup:FAIL
  test_recursion:PASS:skel_open_and_load 0 nsec
  libbpf: prog 'on_lookup': failed to attach: ERROR: strerror_r(-524)=22
  libbpf: prog 'on_lookup': failed to auto-attach: -524
  test_recursion:FAIL:skel_attach unexpected error: -524 (errno 524)
  #48/3    cgrp_local_storage/recursion:FAIL
  test_yes_rcu_lock:PASS:skel_open 0 nsec
  test_yes_rcu_lock:PASS:skel_load 0 nsec
  libbpf: prog 'yes_rcu_lock': failed to attach: ERROR: strerror_r(-524)=22
  libbpf: prog 'yes_rcu_lock': failed to auto-attach: -524
  test_yes_rcu_lock:FAIL:skel_attach unexpected error: -524 (errno 524)
  #48/6    cgrp_local_storage/yes_rcu_lock:FAIL
  #48      cgrp_local_storage:FAIL
  Summary: 0/4 PASSED, 0 SKIPPED, 1 FAILED

No panics any more (The test still failed because lack of BPF trampoline
which I am actively working on).

Fixes: 5dc6155 ("LoongArch: Add BPF JIT support")
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
frank-w pushed a commit that referenced this pull request May 9, 2024
Currently normal HugeTLB fault ends up crashing the kernel, as p4dp derived
from p4d_offset() is an invalid address when PGTABLE_LEVEL = 5. A p4d level
entry needs to be allocated when not available while walking the page table
during HugeTLB faults. Let's call p4d_alloc() to allocate such entries when
required instead of current p4d_offset().

 Unable to handle kernel paging request at virtual address ffffffff80000000
 Mem abort info:
   ESR = 0x0000000096000005
   EC = 0x25: DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
   FSC = 0x05: level 1 translation fault
 Data abort info:
   ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
 swapper pgtable: 4k pages, 52-bit VAs, pgdp=0000000081da9000
 [ffffffff80000000] pgd=1000000082cec003, p4d=0000000082c32003, pud=0000000000000000
 Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
 Modules linked in:
 CPU: 1 PID: 108 Comm: high_addr_hugep Not tainted 6.9.0-rc4 #48
 Hardware name: Foundation-v8A (DT)
 pstate: 01402005 (nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
 pc : huge_pte_alloc+0xd4/0x334
 lr : hugetlb_fault+0x1b8/0xc68
 sp : ffff8000833bbc20
 x29: ffff8000833bbc20 x28: fff000080080cb58 x27: ffff800082a7cc58
 x26: 0000000000000000 x25: fff0000800378e40 x24: fff00008008d6c60
 x23: 00000000de9dbf07 x22: fff0000800378e40 x21: 0004000000000000
 x20: 0004000000000000 x19: ffffffff80000000 x18: 1ffe00010011d7a1
 x17: 0000000000000001 x16: ffffffffffffffff x15: 0000000000000001
 x14: 0000000000000000 x13: ffff8000816120d0 x12: ffffffffffffffff
 x11: 0000000000000000 x10: fff00008008ebd0c x9 : 0004000000000000
 x8 : 0000000000001255 x7 : fff00008003e2000 x6 : 00000000061d54b0
 x5 : 0000000000001000 x4 : ffffffff80000000 x3 : 0000000000200000
 x2 : 0000000000000004 x1 : 0000000080000000 x0 : 0000000000000000
 Call trace:
 huge_pte_alloc+0xd4/0x334
 hugetlb_fault+0x1b8/0xc68
 handle_mm_fault+0x260/0x29c
 do_page_fault+0xfc/0x47c
 do_translation_fault+0x68/0x74
 do_mem_abort+0x44/0x94
 el0_da+0x2c/0x9c
 el0t_64_sync_handler+0x70/0xc4
 el0t_64_sync+0x190/0x194
 Code: aa000084 cb010084 b24c2c84 8b130c93 (f9400260)
 ---[ end trace 0000000000000000 ]---

Cc: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Fixes: a6bbf5d ("arm64: mm: Add definitions to support 5 levels of paging")
Reported-by: Dev Jain <dev.jain@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Link: https://lore.kernel.org/r/20240415094003.1812018-1-anshuman.khandual@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
frank-w pushed a commit that referenced this pull request Nov 3, 2024
During the migration of Soundwire runtime stream allocation from
the Qualcomm Soundwire controller to SoC's soundcard drivers the sdm845
soundcard was forgotten.

At this point any playback attempt or audio daemon startup, for instance
on sdm845-db845c (Qualcomm RB3 board), will result in stream pointer
NULL dereference:

 Unable to handle kernel NULL pointer dereference at virtual
 address 0000000000000020
 Mem abort info:
   ESR = 0x0000000096000004
   EC = 0x25: DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
   FSC = 0x04: level 0 translation fault
 Data abort info:
   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
 user pgtable: 4k pages, 48-bit VAs, pgdp=0000000101ecf000
 [0000000000000020] pgd=0000000000000000, p4d=0000000000000000
 Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
 Modules linked in: ...
 CPU: 5 UID: 0 PID: 1198 Comm: aplay
 Not tainted 6.12.0-rc2-qcomlt-arm64-00059-g9d78f315a362-dirty #18
 Hardware name: Thundercomm Dragonboard 845c (DT)
 pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : sdw_stream_add_slave+0x44/0x380 [soundwire_bus]
 lr : sdw_stream_add_slave+0x44/0x380 [soundwire_bus]
 sp : ffff80008a2035c0
 x29: ffff80008a2035c0 x28: ffff80008a203978 x27: 0000000000000000
 x26: 00000000000000c0 x25: 0000000000000000 x24: ffff1676025f4800
 x23: ffff167600ff1cb8 x22: ffff167600ff1c98 x21: 0000000000000003
 x20: ffff167607316000 x19: ffff167604e64e80 x18: 0000000000000000
 x17: 0000000000000000 x16: ffffcec265074160 x15: 0000000000000000
 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
 x8 : 0000000000000000 x7 : 0000000000000000 x6 : ffff167600ff1cec
 x5 : ffffcec22cfa2010 x4 : 0000000000000000 x3 : 0000000000000003
 x2 : ffff167613f836c0 x1 : 0000000000000000 x0 : ffff16761feb60b8
 Call trace:
  sdw_stream_add_slave+0x44/0x380 [soundwire_bus]
  wsa881x_hw_params+0x68/0x80 [snd_soc_wsa881x]
  snd_soc_dai_hw_params+0x3c/0xa4
  __soc_pcm_hw_params+0x230/0x660
  dpcm_be_dai_hw_params+0x1d0/0x3f8
  dpcm_fe_dai_hw_params+0x98/0x268
  snd_pcm_hw_params+0x124/0x460
  snd_pcm_common_ioctl+0x998/0x16e8
  snd_pcm_ioctl+0x34/0x58
  __arm64_sys_ioctl+0xac/0xf8
  invoke_syscall+0x48/0x104
  el0_svc_common.constprop.0+0x40/0xe0
  do_el0_svc+0x1c/0x28
  el0_svc+0x34/0xe0
  el0t_64_sync_handler+0x120/0x12c
  el0t_64_sync+0x190/0x194
 Code: aa0403fb f9418400 9100e000 9400102f (f8420f22)
 ---[ end trace 0000000000000000 ]---

0000000000006108 <sdw_stream_add_slave>:
    6108:       d503233f        paciasp
    610c:       a9b97bfd        stp     x29, x30, [sp, #-112]!
    6110:       910003fd        mov     x29, sp
    6114:       a90153f3        stp     x19, x20, [sp, #16]
    6118:       a9025bf5        stp     x21, x22, [sp, #32]
    611c:       aa0103f6        mov     x22, x1
    6120:       2a0303f5        mov     w21, w3
    6124:       a90363f7        stp     x23, x24, [sp, #48]
    6128:       aa0003f8        mov     x24, x0
    612c:       aa0203f7        mov     x23, x2
    6130:       a9046bf9        stp     x25, x26, [sp, #64]
    6134:       aa0403f9        mov     x25, x4        <-- x4 copied to x25
    6138:       a90573fb        stp     x27, x28, [sp, #80]
    613c:       aa0403fb        mov     x27, x4
    6140:       f9418400        ldr     x0, [x0, #776]
    6144:       9100e000        add     x0, x0, #0x38
    6148:       94000000        bl      0 <mutex_lock>
    614c:       f8420f22        ldr     x2, [x25, #32]!  <-- offset 0x44
    ^^^
This is 0x6108 + offset 0x44 from the beginning of sdw_stream_add_slave()
where data abort happens.
wsa881x_hw_params() is called with stream = NULL and passes it further
in register x4 (5th argument) to sdw_stream_add_slave() without any checks.
Value from x4 is copied to x25 and finally it aborts on trying to load
a value from address in x25 plus offset 32 (in dec) which corresponds
to master_list member in struct sdw_stream_runtime:

struct sdw_stream_runtime {
        const char  *              name;	/*     0     8 */
        struct sdw_stream_params   params;	/*     8    12 */
        enum sdw_stream_state      state;	/*    20     4 */
        enum sdw_stream_type       type;	/*    24     4 */
        /* XXX 4 bytes hole, try to pack */
 here-> struct list_head           master_list;	/*    32    16 */
        int                        m_rt_count;	/*    48     4 */
        /* size: 56, cachelines: 1, members: 6 */
        /* sum members: 48, holes: 1, sum holes: 4 */
        /* padding: 4 */
        /* last cacheline: 56 bytes */

Fix this by adding required calls to qcom_snd_sdw_startup() and
sdw_release_stream() to startup and shutdown routines which restores
the previous correct behaviour when ->set_stream() method is called to
set a valid stream runtime pointer on playback startup.

Reproduced and then fix was tested on db845c RB3 board.

Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: stable@vger.kernel.org
Fixes: 15c7fab ("ASoC: qcom: Move Soundwire runtime stream alloc to soundcards")
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
Tested-by: Steev Klimaszewski <steev@kali.org> # Lenovo Yoga C630
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://patch.msgid.link/20241009213922.999355-1-alexey.klimov@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
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