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tools: bpftool: print built-in features, automate some of the documentation #18

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tools: bpftool: print built-in features, automate some of the documentation #18

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kernel-patches-bot
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Pull request for series with
subject: tools: bpftool: print built-in features, automate some of the documentation
version: 2
url: https://patchwork.ozlabs.org/project/netdev/list/?series=200009

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Master branch: bc0b5a0
series: https://patchwork.ozlabs.org/project/netdev/list/?series=200009
version: 2

patch https://patchwork.ozlabs.org/project/netdev/patch/20200907163804.29244-2-quentin@isovalent.com/ applied successfully
patch https://patchwork.ozlabs.org/project/netdev/patch/20200907163804.29244-3-quentin@isovalent.com/ applied successfully
patch https://patchwork.ozlabs.org/project/netdev/patch/20200907163804.29244-4-quentin@isovalent.com/ applied successfully

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Master branch: e6054fc
series: https://patchwork.ozlabs.org/project/netdev/list/?series=200009
version: 2

patch https://patchwork.ozlabs.org/project/netdev/patch/20200907163804.29244-2-quentin@isovalent.com/ applied successfully
patch https://patchwork.ozlabs.org/project/netdev/patch/20200907163804.29244-3-quentin@isovalent.com/ applied successfully
patch https://patchwork.ozlabs.org/project/netdev/patch/20200907163804.29244-4-quentin@isovalent.com/ applied successfully

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Master branch: e6054fc
series: https://patchwork.ozlabs.org/project/netdev/list/?series=200563
version: 3

patch https://patchwork.ozlabs.org/project/netdev/patch/20200909162500.17010-2-quentin@isovalent.com/ applied successfully
patch https://patchwork.ozlabs.org/project/netdev/patch/20200909162500.17010-3-quentin@isovalent.com/ applied successfully
patch https://patchwork.ozlabs.org/project/netdev/patch/20200909162500.17010-4-quentin@isovalent.com/ applied successfully

@kernel-patches-bot kernel-patches-bot added V3 and removed V2 labels Sep 9, 2020
@kernel-patches-bot
adding ci files
1ee29b5
@qmonnet @kernel-patches-bot
Bpftool has a number of features that can be included or left aside
9f40de5 
during compilation. This includes:

- Support for libbfd, providing the disassembler for JIT-compiled
  programs.
- Support for BPF skeletons, used for profiling programs or iterating on
  the PIDs of processes associated with BPF objects.

In order to make it easy for users to understand what features were
compiled for a given bpftool binary, print the status of the two
features above when showing the version number for bpftool ("bpftool -V"
or "bpftool version"). Document this in the main manual page. Example
invocations:

    $ bpftool version
    ./bpftool v5.9.0-rc1
    features: libbfd, skeletons

    $ bpftool -p version
    {
        "version": "5.9.0-rc1",
        "features": {
            "libbfd": true,
            "skeletons": true
        }
    }

Some other parameters are optional at compilation
("DISASM_FOUR_ARGS_SIGNATURE", LIBCAP support) but they do not impact
significantly bpftool's behaviour from a user's point of view, so their
status is not reported.

Available commands and supported program types depend on the version
number, and are therefore not reported either. Note that they are
already available, albeit without JSON, via bpftool's help messages.

v3:
- Use a simple list instead of boolean values for plain output.

v2:
- Fix JSON (object instead or array for the features).

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
---
 tools/bpf/bpftool/Documentation/bpftool.rst |  8 ++++-
 tools/bpf/bpftool/main.c                    | 33 +++++++++++++++++++--
 2 files changed, 38 insertions(+), 3 deletions(-)
@qmonnet @kernel-patches-bot
Nearly all man pages for bpftool have the same common set of option
fe362d7 
flags (--help, --version, --json, --pretty, --debug). The description is
duplicated across all the pages, which is more difficult to maintain if
the description of an option changes. It may also be confusing to sort
out what options are not "common" and should not be copied when creating
new manual pages.

Let's move the description for those common options to a separate file,
which is included with a RST directive when generating the man pages.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
---
 tools/bpf/bpftool/Documentation/Makefile      |  2 +-
 .../bpf/bpftool/Documentation/bpftool-btf.rst | 17 +------------
 .../bpftool/Documentation/bpftool-cgroup.rst  | 17 +------------
 .../bpftool/Documentation/bpftool-feature.rst | 17 +------------
 .../bpf/bpftool/Documentation/bpftool-gen.rst | 17 +------------
 .../bpftool/Documentation/bpftool-iter.rst    | 11 +--------
 .../bpftool/Documentation/bpftool-link.rst    | 17 +------------
 .../bpf/bpftool/Documentation/bpftool-map.rst | 17 +------------
 .../bpf/bpftool/Documentation/bpftool-net.rst | 17 +------------
 .../bpftool/Documentation/bpftool-perf.rst    | 17 +------------
 .../bpftool/Documentation/bpftool-prog.rst    | 18 +-------------
 .../Documentation/bpftool-struct_ops.rst      | 18 +-------------
 tools/bpf/bpftool/Documentation/bpftool.rst   | 24 +------------------
 .../bpftool/Documentation/common_options.rst  | 22 +++++++++++++++++
 14 files changed, 35 insertions(+), 196 deletions(-)
 create mode 100644 tools/bpf/bpftool/Documentation/common_options.rst
@qmonnet @kernel-patches-bot
The "SEE ALSO" sections of bpftool's manual pages refer to bpf(2),
bc1c539 
bpf-helpers(7), then all existing bpftool man pages (save the current
one).

This leads to nearly-identical lists being duplicated in all manual
pages. Ideally, when a new page is created, all lists should be updated
accordingly, but this has led to omissions and inconsistencies multiple
times in the past.

Let's take it out of the RST files and generate the "SEE ALSO" sections
automatically in the Makefile when generating the man pages. The lists
are not really useful in the RST anyway because all other pages are
available in the same directory.

v2:
- Use "echo -n" instead of "printf" in Makefile, to avoid any risk of
  passing a format string directly to the command.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
---
 tools/bpf/bpftool/Documentation/Makefile        | 12 +++++++++++-
 tools/bpf/bpftool/Documentation/bpftool-btf.rst | 17 -----------------
 .../bpftool/Documentation/bpftool-cgroup.rst    | 16 ----------------
 .../bpftool/Documentation/bpftool-feature.rst   | 16 ----------------
 tools/bpf/bpftool/Documentation/bpftool-gen.rst | 16 ----------------
 .../bpf/bpftool/Documentation/bpftool-iter.rst  | 16 ----------------
 .../bpf/bpftool/Documentation/bpftool-link.rst  | 17 -----------------
 tools/bpf/bpftool/Documentation/bpftool-map.rst | 16 ----------------
 tools/bpf/bpftool/Documentation/bpftool-net.rst | 17 -----------------
 .../bpf/bpftool/Documentation/bpftool-perf.rst  | 17 -----------------
 .../bpf/bpftool/Documentation/bpftool-prog.rst  | 16 ----------------
 .../Documentation/bpftool-struct_ops.rst        | 17 -----------------
 tools/bpf/bpftool/Documentation/bpftool.rst     | 16 ----------------
 13 files changed, 11 insertions(+), 198 deletions(-)
@kernel-patches-bot
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Master branch: 8081ede
series: https://patchwork.ozlabs.org/project/netdev/list/?series=200563
version: 3

patch https://patchwork.ozlabs.org/project/netdev/patch/20200909162500.17010-2-quentin@isovalent.com/ applied successfully
patch https://patchwork.ozlabs.org/project/netdev/patch/20200909162500.17010-3-quentin@isovalent.com/ applied successfully
patch https://patchwork.ozlabs.org/project/netdev/patch/20200909162500.17010-4-quentin@isovalent.com/ applied successfully

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At least one diff in series https://patchwork.ozlabs.org/project/netdev/list/?series=200563 irrelevant now. Closing PR.

@kernel-patches-bot kernel-patches-bot deleted the series/199637 branch September 15, 2020 17:49
kernel-patches-bot pushed a commit that referenced this pull request Sep 16, 2020
@acmel
perf test: Set NULL sentinel in pmu_events table in "Parse and proces…
492d4d8 
…s metrics" test

Linux 5.9 introduced perf test case "Parse and process metrics" and
on s390 this test case always dumps core:

  [root@t35lp67 perf]# ./perf test -vvvv -F 67
  67: Parse and process metrics                             :
  --- start ---
  metric expr inst_retired.any / cpu_clk_unhalted.thread for IPC
  parsing metric: inst_retired.any / cpu_clk_unhalted.thread
  Segmentation fault (core dumped)
  [root@t35lp67 perf]#

I debugged this core dump and gdb shows this call chain:

  (gdb) where
   #0  0x000003ffabc3192a in __strnlen_c_1 () from /lib64/libc.so.6
   #1  0x000003ffabc293de in strcasestr () from /lib64/libc.so.6
   #2  0x0000000001102ba2 in match_metric(list=0x1e6ea20 "inst_retired.any",
            n=<optimized out>)
       at util/metricgroup.c:368
   #3  find_metric (map=<optimized out>, map=<optimized out>,
           metric=0x1e6ea20 "inst_retired.any")
      at util/metricgroup.c:765
   #4  __resolve_metric (ids=0x0, map=<optimized out>, metric_list=0x0,
           metric_no_group=<optimized out>, m=<optimized out>)
      at util/metricgroup.c:844
   #5  resolve_metric (ids=0x0, map=0x0, metric_list=0x0,
          metric_no_group=<optimized out>)
      at util/metricgroup.c:881
   #6  metricgroup__add_metric (metric=<optimized out>,
        metric_no_group=metric_no_group@entry=false, events=<optimized out>,
        events@entry=0x3ffd84fb878, metric_list=0x0,
        metric_list@entry=0x3ffd84fb868, map=0x0)
      at util/metricgroup.c:943
   #7  0x00000000011034ae in metricgroup__add_metric_list (map=0x13f9828 <map>,
        metric_list=0x3ffd84fb868, events=0x3ffd84fb878,
        metric_no_group=<optimized out>, list=<optimized out>)
      at util/metricgroup.c:988
   #8  parse_groups (perf_evlist=perf_evlist@entry=0x1e70260,
          str=str@entry=0x12f34b2 "IPC", metric_no_group=<optimized out>,
          metric_no_merge=<optimized out>,
          fake_pmu=fake_pmu@entry=0x1462f18 <perf_pmu.fake>,
          metric_events=0x3ffd84fba58, map=0x1)
      at util/metricgroup.c:1040
   #9  0x0000000001103eb2 in metricgroup__parse_groups_test(
  	evlist=evlist@entry=0x1e70260, map=map@entry=0x13f9828 <map>,
  	str=str@entry=0x12f34b2 "IPC",
  	metric_no_group=metric_no_group@entry=false,
  	metric_no_merge=metric_no_merge@entry=false,
  	metric_events=0x3ffd84fba58)
      at util/metricgroup.c:1082
   #10 0x00000000010c84d8 in __compute_metric (ratio2=0x0, name2=0x0,
          ratio1=<synthetic pointer>, name1=0x12f34b2 "IPC",
  	vals=0x3ffd84fbad8, name=0x12f34b2 "IPC")
      at tests/parse-metric.c:159
   #11 compute_metric (ratio=<synthetic pointer>, vals=0x3ffd84fbad8,
  	name=0x12f34b2 "IPC")
      at tests/parse-metric.c:189
   #12 test_ipc () at tests/parse-metric.c:208
.....
..... omitted many more lines

This test case was added with
commit 218ca91 ("perf tests: Add parse metric test for frontend metric").

When I compile with make DEBUG=y it works fine and I do not get a core dump.

It turned out that the above listed function call chain worked on a struct
pmu_event array which requires a trailing element with zeroes which was
missing. The marco map_for_each_event() loops over that array tests for members
metric_expr/metric_name/metric_group being non-NULL. Adding this element fixes
the issue.

Output after:

  [root@t35lp46 perf]# ./perf test 67
  67: Parse and process metrics                             : Ok
  [root@t35lp46 perf]#

Committer notes:

As Ian remarks, this is not s390 specific:

<quote Ian>
  This also shows up with address sanitizer on all architectures
  (perhaps change the patch title) and perhaps add a "Fixes: <commit>"
  tag.

  =================================================================
  ==4718==ERROR: AddressSanitizer: global-buffer-overflow on address
  0x55c93b4d59e8 at pc 0x55c93a1541e2 bp 0x7ffd24327c60 sp
  0x7ffd24327c58
  READ of size 8 at 0x55c93b4d59e8 thread T0
      #0 0x55c93a1541e1 in find_metric tools/perf/util/metricgroup.c:764:2
      #1 0x55c93a153e6c in __resolve_metric tools/perf/util/metricgroup.c:844:9
      #2 0x55c93a152f18 in resolve_metric tools/perf/util/metricgroup.c:881:9
      #3 0x55c93a1528db in metricgroup__add_metric
  tools/perf/util/metricgroup.c:943:9
      #4 0x55c93a151996 in metricgroup__add_metric_list
  tools/perf/util/metricgroup.c:988:9
      #5 0x55c93a1511b9 in parse_groups tools/perf/util/metricgroup.c:1040:8
      #6 0x55c93a1513e1 in metricgroup__parse_groups_test
  tools/perf/util/metricgroup.c:1082:9
      #7 0x55c93a0108ae in __compute_metric tools/perf/tests/parse-metric.c:159:8
      #8 0x55c93a010744 in compute_metric tools/perf/tests/parse-metric.c:189:9
      #9 0x55c93a00f5ee in test_ipc tools/perf/tests/parse-metric.c:208:2
      #10 0x55c93a00f1e8 in test__parse_metric
  tools/perf/tests/parse-metric.c:345:2
      #11 0x55c939fd7202 in run_test tools/perf/tests/builtin-test.c:410:9
      #12 0x55c939fd6736 in test_and_print tools/perf/tests/builtin-test.c:440:9
      #13 0x55c939fd58c3 in __cmd_test tools/perf/tests/builtin-test.c:661:4
      #14 0x55c939fd4e02 in cmd_test tools/perf/tests/builtin-test.c:807:9
      #15 0x55c939e4763d in run_builtin tools/perf/perf.c:313:11
      #16 0x55c939e46475 in handle_internal_command tools/perf/perf.c:365:8
      #17 0x55c939e4737e in run_argv tools/perf/perf.c:409:2
      #18 0x55c939e45f7e in main tools/perf/perf.c:539:3

  0x55c93b4d59e8 is located 0 bytes to the right of global variable
  'pme_test' defined in 'tools/perf/tests/parse-metric.c:17:25'
  (0x55c93b4d54a0) of size 1352
  SUMMARY: AddressSanitizer: global-buffer-overflow
  tools/perf/util/metricgroup.c:764:2 in find_metric
  Shadow bytes around the buggy address:
    0x0ab9a7692ae0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692af0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  =>0x0ab9a7692b30: 00 00 00 00 00 00 00 00 00 00 00 00 00[f9]f9 f9
    0x0ab9a7692b40: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
    0x0ab9a7692b50: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
    0x0ab9a7692b60: f9 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 00 00 00 00
    0x0ab9a7692b70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b80: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
  Shadow byte legend (one shadow byte represents 8 application bytes):
    Addressable:           00
    Partially addressable: 01 02 03 04 05 06 07
    Heap left redzone:	   fa
    Freed heap region:	   fd
    Stack left redzone:	   f1
    Stack mid redzone:	   f2
    Stack right redzone:     f3
    Stack after return:	   f5
    Stack use after scope:   f8
    Global redzone:          f9
    Global init order:	   f6
    Poisoned by user:        f7
    Container overflow:	   fc
    Array cookie:            ac
    Intra object redzone:    bb
    ASan internal:           fe
    Left alloca redzone:     ca
    Right alloca redzone:    cb
    Shadow gap:              cc
</quote>

I'm also adding the missing "Fixes" tag and setting just .name to NULL,
as doing it that way is more compact (the compiler will zero out
everything else) and the table iterators look for .name being NULL as
the sentinel marking the end of the table.

Fixes: 0a507af ("perf tests: Add parse metric test for ipc metric")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20200825071211.16959-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-bot pushed a commit that referenced this pull request Sep 24, 2020
@namhyung @acmel
perf parse-event: Fix memory leak in evsel->unit
b12eea5 
The evsel->unit borrows a pointer of pmu event or alias instead of
owns a string.  But tool event (duration_time) passes a result of
strdup() caused a leak.

It was found by ASAN during metric test:

  Direct leak of 210 byte(s) in 70 object(s) allocated from:
    #0 0x7fe366fca0b5 in strdup (/lib/x86_64-linux-gnu/libasan.so.5+0x920b5)
    #1 0x559fbbcc6ea3 in add_event_tool util/parse-events.c:414
    #2 0x559fbbcc6ea3 in parse_events_add_tool util/parse-events.c:1414
    #3 0x559fbbd8474d in parse_events_parse util/parse-events.y:439
    #4 0x559fbbcc95da in parse_events__scanner util/parse-events.c:2096
    #5 0x559fbbcc95da in __parse_events util/parse-events.c:2141
    #6 0x559fbbc28555 in check_parse_id tests/pmu-events.c:406
    #7 0x559fbbc28555 in check_parse_id tests/pmu-events.c:393
    #8 0x559fbbc28555 in check_parse_cpu tests/pmu-events.c:415
    #9 0x559fbbc28555 in test_parsing tests/pmu-events.c:498
    #10 0x559fbbc0109b in run_test tests/builtin-test.c:410
    #11 0x559fbbc0109b in test_and_print tests/builtin-test.c:440
    #12 0x559fbbc03e69 in __cmd_test tests/builtin-test.c:695
    #13 0x559fbbc03e69 in cmd_test tests/builtin-test.c:807
    #14 0x559fbbc691f4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    #15 0x559fbbb071a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    #16 0x559fbbb071a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    #17 0x559fbbb071a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    #18 0x7fe366b68cc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: f0fbb11 ("perf stat: Implement duration_time as a proper event")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200915031819.386559-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-bot pushed a commit that referenced this pull request Sep 24, 2020
@namhyung @acmel
perf metric: Release expr_parse_ctx after testing
437822b 
The test_generic_metric() missed to release entries in the pctx.  Asan
reported following leak (and more):

  Direct leak of 128 byte(s) in 1 object(s) allocated from:
    #0 0x7f4c9396980e in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10780e)
    #1 0x55f7e748cc14 in hashmap_grow (/home/namhyung/project/linux/tools/perf/perf+0x90cc14)
    #2 0x55f7e748d497 in hashmap__insert (/home/namhyung/project/linux/tools/perf/perf+0x90d497)
    #3 0x55f7e7341667 in hashmap__set /home/namhyung/project/linux/tools/perf/util/hashmap.h:111
    #4 0x55f7e7341667 in expr__add_ref util/expr.c:120
    #5 0x55f7e7292436 in prepare_metric util/stat-shadow.c:783
    #6 0x55f7e729556d in test_generic_metric util/stat-shadow.c:858
    #7 0x55f7e712390b in compute_single tests/parse-metric.c:128
    #8 0x55f7e712390b in __compute_metric tests/parse-metric.c:180
    #9 0x55f7e712446d in compute_metric tests/parse-metric.c:196
    #10 0x55f7e712446d in test_dcache_l2 tests/parse-metric.c:295
    #11 0x55f7e712446d in test__parse_metric tests/parse-metric.c:355
    #12 0x55f7e70be09b in run_test tests/builtin-test.c:410
    #13 0x55f7e70be09b in test_and_print tests/builtin-test.c:440
    #14 0x55f7e70c101a in __cmd_test tests/builtin-test.c:661
    #15 0x55f7e70c101a in cmd_test tests/builtin-test.c:807
    #16 0x55f7e7126214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    #17 0x55f7e6fc41a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    #18 0x55f7e6fc41a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    #19 0x55f7e6fc41a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    #20 0x7f4c93492cc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: 6d432c4 ("perf tools: Add test_generic_metric function")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200915031819.386559-8-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-bot pushed a commit that referenced this pull request Sep 24, 2020
@namhyung @acmel
perf metric: Free metric when it failed to resolve
27adafc 
The metricgroup__add_metric() can find multiple match for a metric group
and it's possible to fail.  Also it can fail in the middle like in
resolve_metric() even for single metric.

In those cases, the intermediate list and ids will be leaked like:

  Direct leak of 3 byte(s) in 1 object(s) allocated from:
    #0 0x7f4c938f40b5 in strdup (/lib/x86_64-linux-gnu/libasan.so.5+0x920b5)
    #1 0x55f7e71c1bef in __add_metric util/metricgroup.c:683
    #2 0x55f7e71c31d0 in add_metric util/metricgroup.c:906
    #3 0x55f7e71c3844 in metricgroup__add_metric util/metricgroup.c:940
    #4 0x55f7e71c488d in metricgroup__add_metric_list util/metricgroup.c:993
    #5 0x55f7e71c488d in parse_groups util/metricgroup.c:1045
    #6 0x55f7e71c60a4 in metricgroup__parse_groups_test util/metricgroup.c:1087
    #7 0x55f7e71235ae in __compute_metric tests/parse-metric.c:164
    #8 0x55f7e7124650 in compute_metric tests/parse-metric.c:196
    #9 0x55f7e7124650 in test_recursion_fail tests/parse-metric.c:318
    #10 0x55f7e7124650 in test__parse_metric tests/parse-metric.c:356
    #11 0x55f7e70be09b in run_test tests/builtin-test.c:410
    #12 0x55f7e70be09b in test_and_print tests/builtin-test.c:440
    #13 0x55f7e70c101a in __cmd_test tests/builtin-test.c:661
    #14 0x55f7e70c101a in cmd_test tests/builtin-test.c:807
    #15 0x55f7e7126214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    #16 0x55f7e6fc41a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    #17 0x55f7e6fc41a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    #18 0x55f7e6fc41a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    #19 0x7f4c93492cc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: 83de0b7 ("perf metric: Collect referenced metrics in struct metric_ref_node")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200915031819.386559-9-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-bot pushed a commit that referenced this pull request Nov 16, 2020
@marckleinebudde
can: rx-offload: don't call kfree_skb() from IRQ context
2ddd6bf 
A CAN driver, using the rx-offload infrastructure, is reading CAN frames
(usually in IRQ context) from the hardware and placing it into the rx-offload
queue to be delivered to the networking stack via NAPI.

In case the rx-offload queue is full, trying to add more skbs results in the
skbs being dropped using kfree_skb(). If done from hard-IRQ context this
results in the following warning:

[  682.552693] ------------[ cut here ]------------
[  682.557360] WARNING: CPU: 0 PID: 3057 at net/core/skbuff.c:650 skb_release_head_state+0x74/0x84
[  682.566075] Modules linked in: can_raw can coda_vpu flexcan dw_hdmi_ahb_audio v4l2_jpeg imx_vdoa can_dev
[  682.575597] CPU: 0 PID: 3057 Comm: cansend Tainted: G        W         5.7.0+ #18
[  682.583098] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[  682.589657] [<c0112628>] (unwind_backtrace) from [<c010c1c4>] (show_stack+0x10/0x14)
[  682.597423] [<c010c1c4>] (show_stack) from [<c06c481c>] (dump_stack+0xe0/0x114)
[  682.604759] [<c06c481c>] (dump_stack) from [<c0128f10>] (__warn+0xc0/0x10c)
[  682.611742] [<c0128f10>] (__warn) from [<c0129314>] (warn_slowpath_fmt+0x5c/0xc0)
[  682.619248] [<c0129314>] (warn_slowpath_fmt) from [<c0b95dec>] (skb_release_head_state+0x74/0x84)
[  682.628143] [<c0b95dec>] (skb_release_head_state) from [<c0b95e08>] (skb_release_all+0xc/0x24)
[  682.636774] [<c0b95e08>] (skb_release_all) from [<c0b95eac>] (kfree_skb+0x74/0x1c8)
[  682.644479] [<c0b95eac>] (kfree_skb) from [<bf001d1c>] (can_rx_offload_queue_sorted+0xe0/0xe8 [can_dev])
[  682.654051] [<bf001d1c>] (can_rx_offload_queue_sorted [can_dev]) from [<bf001d6c>] (can_rx_offload_get_echo_skb+0x48/0x94 [can_dev])
[  682.666007] [<bf001d6c>] (can_rx_offload_get_echo_skb [can_dev]) from [<bf01efe4>] (flexcan_irq+0x194/0x5dc [flexcan])
[  682.676734] [<bf01efe4>] (flexcan_irq [flexcan]) from [<c019c1ec>] (__handle_irq_event_percpu+0x4c/0x3ec)
[  682.686322] [<c019c1ec>] (__handle_irq_event_percpu) from [<c019c5b8>] (handle_irq_event_percpu+0x2c/0x88)
[  682.695993] [<c019c5b8>] (handle_irq_event_percpu) from [<c019c64c>] (handle_irq_event+0x38/0x5c)
[  682.704887] [<c019c64c>] (handle_irq_event) from [<c01a1058>] (handle_fasteoi_irq+0xc8/0x180)
[  682.713432] [<c01a1058>] (handle_fasteoi_irq) from [<c019b2c0>] (generic_handle_irq+0x30/0x44)
[  682.722063] [<c019b2c0>] (generic_handle_irq) from [<c019b8f8>] (__handle_domain_irq+0x64/0xdc)
[  682.730783] [<c019b8f8>] (__handle_domain_irq) from [<c06df4a4>] (gic_handle_irq+0x48/0x9c)
[  682.739158] [<c06df4a4>] (gic_handle_irq) from [<c0100b30>] (__irq_svc+0x70/0x98)
[  682.746656] Exception stack(0xe80e9dd8 to 0xe80e9e20)
[  682.751725] 9dc0:                                                       00000001 e80e8000
[  682.759922] 9de0: e820cf80 00000000 ffffe000 00000000 eaf08fe4 00000000 600d0013 00000000
[  682.768117] 9e00: c1732e3c c16093a8 e820d4c0 e80e9e28 c018a57c c018b870 600d0013 ffffffff
[  682.776315] [<c0100b30>] (__irq_svc) from [<c018b870>] (lock_acquire+0x108/0x4e8)
[  682.783821] [<c018b870>] (lock_acquire) from [<c0e938e4>] (down_write+0x48/0xa8)
[  682.791242] [<c0e938e4>] (down_write) from [<c02818dc>] (unlink_file_vma+0x24/0x40)
[  682.798922] [<c02818dc>] (unlink_file_vma) from [<c027a258>] (free_pgtables+0x34/0xb8)
[  682.806858] [<c027a258>] (free_pgtables) from [<c02835a4>] (exit_mmap+0xe4/0x170)
[  682.814361] [<c02835a4>] (exit_mmap) from [<c01248e0>] (mmput+0x5c/0x110)
[  682.821171] [<c01248e0>] (mmput) from [<c012e910>] (do_exit+0x374/0xbe4)
[  682.827892] [<c012e910>] (do_exit) from [<c0130888>] (do_group_exit+0x38/0xb4)
[  682.835132] [<c0130888>] (do_group_exit) from [<c0130914>] (__wake_up_parent+0x0/0x14)
[  682.843063] irq event stamp: 1936
[  682.846399] hardirqs last  enabled at (1935): [<c02938b0>] rmqueue+0xf4/0xc64
[  682.853553] hardirqs last disabled at (1936): [<c0100b20>] __irq_svc+0x60/0x98
[  682.860799] softirqs last  enabled at (1878): [<bf04cdcc>] raw_release+0x108/0x1f0 [can_raw]
[  682.869256] softirqs last disabled at (1876): [<c0b8f478>] release_sock+0x18/0x98
[  682.876753] ---[ end trace 7bca4751ce44c444 ]---

This patch fixes the problem by replacing the kfree_skb() by
dev_kfree_skb_any(), as rx-offload might be called from threaded IRQ handlers
as well.

Fixes: ca913f1 ("can: rx-offload: can_rx_offload_queue_sorted(): fix error handling, avoid skb mem leak")
Fixes: 6caf8a6 ("can: rx-offload: can_rx_offload_queue_tail(): fix error handling, avoid skb mem leak")
Link: http://lore.kernel.org/r/20201019190524.1285319-3-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
kernel-patches-bot pushed a commit that referenced this pull request Nov 16, 2020
@kuba-moo
Merge branch 'nexthop-add-support-for-nexthop-objects-offload'
3b4202a 
Ido Schimmel says:

====================
nexthop: Add support for nexthop objects offload

This patch set adds support for nexthop objects offload with a dummy
implementation over netdevsim. mlxsw support will be added later.

The general idea is very similar to route offload in that notifications
are sent whenever nexthop objects are changed. A listener can veto the
change and the error will be communicated to user space with extack.

To keep listeners as simple as possible, they not only receive
notifications for the nexthop object that is changed, but also for all
the other objects affected by this change. For example, when a single
nexthop is replaced, a replace notification is sent for the single
nexthop, but also for all the nexthop groups this nexthop is member in.
This relieves listeners from the need to track such dependencies.

To simplify things further for listeners, the notification info does not
contain the raw nexthop data structures (e.g., 'struct nexthop'), but
less complex data structures into which the raw data structures are
parsed into.

Tested with a new selftest over netdevsim and with fib_nexthops.sh:

Tests passed: 164
Tests failed:   0

Patch set overview:

Patches #1-#4 introduce the aforementioned data structures and convert
existing listeners (i.e., the VXLAN driver) to use them.

Patches #5-#6 add a new RTNH_F_TRAP flag and the ability to set it and
RTNH_F_OFFLOAD on nexthops. This flag is used by netdevsim for testing
purposes and will also be used by mlxsw. These flags are consistent with
the existing RTM_F_OFFLOAD and RTM_F_TRAP flags.

Patches #7-#14 gradually add the new nexthop notifications.

Patches #15-#18 add a dummy implementation for nexthop offload over
netdevsim and a selftest to exercise both good and bad flows.

Changes since RFC [1]:

Patch #1: s/is_encap/has_encap/
Patch #3: Add a blank line in __nh_notifier_single_info_init()
Patch #5: Reword commit message
Patch #6: s/nexthop_hw_flags_set/nexthop_set_hw_flags/
Patch #7: Reword commit message
Patch #11: Allocate extack on the stack

Follow-up patch sets:

selftests: forwarding: Add nexthop objects tests
mlxsw: Preparations for nexthop objects support - part 1/2
mlxsw: Preparations for nexthop objects support - part 2/2
mlxsw: Add support for nexthop objects
mlxsw: Add support for blackhole nexthops
mlxsw: Update adjacency index more efficiently

[1] https://lore.kernel.org/netdev/20200908091037.2709823-1-idosch@idosch.org/
====================

Link: https://lore.kernel.org/r/20201104133040.1125369-1-idosch@idosch.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
kernel-patches-bot pushed a commit that referenced this pull request Nov 20, 2020
@captain5050 @acmel
perf test: Avoid an msan warning in a copied stack.
568beb2 
This fix is for a failure that occurred in the DWARF unwind perf test.

Stack unwinders may probe memory when looking for frames.

Memory sanitizer will poison and track uninitialized memory on the
stack, and on the heap if the value is copied to the heap.

This can lead to false memory sanitizer failures for the use of an
uninitialized value.

Avoid this problem by removing the poison on the copied stack.

The full msan failure with track origins looks like:

==2168==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x559ceb10755b in handle_cfi elfutils/libdwfl/frame_unwind.c:648:8
    #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #23 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceb106acf in __libdwfl_frame_reg_set elfutils/libdwfl/frame_unwind.c:77:22
    #1 0x559ceb106acf in handle_cfi elfutils/libdwfl/frame_unwind.c:627:13
    #2 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #3 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #4 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #5 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #6 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #7 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #8 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #9 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #10 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #11 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #12 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #13 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #14 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #15 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #16 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #17 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #18 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #19 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #20 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #21 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #22 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #23 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #24 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceb106a54 in handle_cfi elfutils/libdwfl/frame_unwind.c:613:9
    #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #23 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceaff8800 in memory_read tools/perf/util/unwind-libdw.c:156:10
    #1 0x559ceb10f053 in expr_eval elfutils/libdwfl/frame_unwind.c:501:13
    #2 0x559ceb1060cc in handle_cfi elfutils/libdwfl/frame_unwind.c:603:18
    #3 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #4 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #5 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #6 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #7 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #8 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #9 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #10 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #11 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #12 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #13 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #14 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #15 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #16 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #17 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #18 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #19 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #20 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #21 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #22 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #23 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #24 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #25 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559cea9027d9 in __msan_memcpy llvm/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:1558:3
    #1 0x559cea9d2185 in sample_ustack tools/perf/arch/x86/tests/dwarf-unwind.c:41:2
    #2 0x559cea9d202c in test__arch_unwind_sample tools/perf/arch/x86/tests/dwarf-unwind.c:72:9
    #3 0x559ceabc9cbd in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:106:6
    #4 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #5 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #6 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #7 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #8 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #9 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #10 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #11 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #12 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #13 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #14 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #15 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #16 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #17 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was created by an allocation of 'bf' in the stack frame of function 'perf_event__synthesize_mmap_events'
    #0 0x559ceafc5f60 in perf_event__synthesize_mmap_events tools/perf/util/synthetic-events.c:445

SUMMARY: MemorySanitizer: use-of-uninitialized-value elfutils/libdwfl/frame_unwind.c:648:8 in handle_cfi
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: clang-built-linux@googlegroups.com
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandeep Dasgupta <sdasgup@google.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201113182053.754625-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 10, 2021
@lorddoskias @kdave
btrfs: don't flush from btrfs_delayed_inode_reserve_metadata
4d14c5c 
Calling btrfs_qgroup_reserve_meta_prealloc from
btrfs_delayed_inode_reserve_metadata can result in flushing delalloc
while holding a transaction and delayed node locks. This is deadlock
prone. In the past multiple commits:

 * ae5e070 ("btrfs: qgroup: don't try to wait flushing if we're
already holding a transaction")

 * 6f23277 ("btrfs: qgroup: don't commit transaction when we already
 hold the handle")

Tried to solve various aspects of this but this was always a
whack-a-mole game. Unfortunately those 2 fixes don't solve a deadlock
scenario involving btrfs_delayed_node::mutex. Namely, one thread
can call btrfs_dirty_inode as a result of reading a file and modifying
its atime:

  PID: 6963   TASK: ffff8c7f3f94c000  CPU: 2   COMMAND: "test"
  #0  __schedule at ffffffffa529e07d
  #1  schedule at ffffffffa529e4ff
  #2  schedule_timeout at ffffffffa52a1bdd
  #3  wait_for_completion at ffffffffa529eeea             <-- sleeps with delayed node mutex held
  #4  start_delalloc_inodes at ffffffffc0380db5
  #5  btrfs_start_delalloc_snapshot at ffffffffc0393836
  #6  try_flush_qgroup at ffffffffc03f04b2
  #7  __btrfs_qgroup_reserve_meta at ffffffffc03f5bb6     <-- tries to reserve space and starts delalloc inodes.
  #8  btrfs_delayed_update_inode at ffffffffc03e31aa      <-- acquires delayed node mutex
  #9  btrfs_update_inode at ffffffffc0385ba8
 #10  btrfs_dirty_inode at ffffffffc038627b               <-- TRANSACTIION OPENED
 #11  touch_atime at ffffffffa4cf0000
 #12  generic_file_read_iter at ffffffffa4c1f123
 #13  new_sync_read at ffffffffa4ccdc8a
 #14  vfs_read at ffffffffa4cd0849
 #15  ksys_read at ffffffffa4cd0bd1
 #16  do_syscall_64 at ffffffffa4a052eb
 #17  entry_SYSCALL_64_after_hwframe at ffffffffa540008c

This will cause an asynchronous work to flush the delalloc inodes to
happen which can try to acquire the same delayed_node mutex:

  PID: 455    TASK: ffff8c8085fa4000  CPU: 5   COMMAND: "kworker/u16:30"
  #0  __schedule at ffffffffa529e07d
  #1  schedule at ffffffffa529e4ff
  #2  schedule_preempt_disabled at ffffffffa529e80a
  #3  __mutex_lock at ffffffffa529fdcb                    <-- goes to sleep, never wakes up.
  #4  btrfs_delayed_update_inode at ffffffffc03e3143      <-- tries to acquire the mutex
  #5  btrfs_update_inode at ffffffffc0385ba8              <-- this is the same inode that pid 6963 is holding
  #6  cow_file_range_inline.constprop.78 at ffffffffc0386be7
  #7  cow_file_range at ffffffffc03879c1
  #8  btrfs_run_delalloc_range at ffffffffc038894c
  #9  writepage_delalloc at ffffffffc03a3c8f
 #10  __extent_writepage at ffffffffc03a4c01
 #11  extent_write_cache_pages at ffffffffc03a500b
 #12  extent_writepages at ffffffffc03a6de2
 #13  do_writepages at ffffffffa4c277eb
 #14  __filemap_fdatawrite_range at ffffffffa4c1e5bb
 #15  btrfs_run_delalloc_work at ffffffffc0380987         <-- starts running delayed nodes
 #16  normal_work_helper at ffffffffc03b706c
 #17  process_one_work at ffffffffa4aba4e4
 #18  worker_thread at ffffffffa4aba6fd
 #19  kthread at ffffffffa4ac0a3d
 #20  ret_from_fork at ffffffffa54001ff

To fully address those cases the complete fix is to never issue any
flushing while holding the transaction or the delayed node lock. This
patch achieves it by calling qgroup_reserve_meta directly which will
either succeed without flushing or will fail and return -EDQUOT. In the
latter case that return value is going to be propagated to
btrfs_dirty_inode which will fallback to start a new transaction. That's
fine as the majority of time we expect the inode will have
BTRFS_DELAYED_NODE_INODE_DIRTY flag set which will result in directly
copying the in-memory state.

Fixes: c53e965 ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 6, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
a0cfa94 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 6, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
c0199f0 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 6, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
ec748dd 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 6, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
7bcfbce 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 7, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
f48e951 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 7, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
64b807e 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 7, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
e6e5eb1 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 7, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
913228b 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 7, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
42c87f6 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 7, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
10f1ce3 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 7, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
08e6dcc 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 7, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
758198c 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 8, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
08a7ea0 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 8, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
4113608 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 8, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
29269a8 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 8, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
6193ebe 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[kernel-patches#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ kernel-patches#18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: NipaLocal <nipa@local>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 8, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
7da49c9 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ #18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 8, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
727f1bd 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ #18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 8, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
04f76a6 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ #18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 8, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
7c952f3 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ #18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 8, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
d04d682 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ #18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 8, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
14d0721 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ #18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 8, 2024
skmsg: skip zero length skb in sk_msg_recvmsg
f300a38 
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:

'''
Oops[#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ #18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
   ... ...
   ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
  ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 0000000c (PPLV0 +PIE +PWE)
 EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
 ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
 BADV: 0000000000000040
 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
        ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160

Code: ...

---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
 .text @ 0x9000000003710000
 .data @ 0x9000000004d70000
 .bss  @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.

The root cause is a zero length skb (skb->len == 0) is put on the queue.

This zero length skb is a TCP FIN packet, which is sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 9, 2024
@borkmann
skmsg: Skip zero length skb in sk_msg_recvmsg
f0c1802 
When running BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, the following kernel panic occurs:

  [...]
  Oops[#1]:
  CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ #18
  Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
     ... ...
     ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
    ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
   CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
   PRMD: 0000000c (PPLV0 +PIE +PWE)
   EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
   ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
  ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
   BADV: 0000000000000040
   PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
  Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
  Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
  Stack : ...
  Call Trace:
  [<9000000004162774>] copy_page_to_iter+0x74/0x1c0
  [<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
  [<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
  [<90000000049aae34>] inet_recvmsg+0x54/0x100
  [<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
  [<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
  [<900000000481e27c>] sys_recvfrom+0x1c/0x40
  [<9000000004c076ec>] do_syscall+0x8c/0xc0
  [<9000000003731da4>] handle_syscall+0xc4/0x160
  Code: ...
  ---[ end trace 0000000000000000 ]---
  Kernel panic - not syncing: Fatal exception
  Kernel relocated by 0x3510000
   .text @ 0x9000000003710000
   .data @ 0x9000000004d70000
   .bss  @ 0x9000000006469400
  ---[ end Kernel panic - not syncing: Fatal exception ]---
  [...]

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in the
sk_msg_recvmsg(). Due to the different implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on x86 platform. So this bug was hidden on x86 platform
for a while, but now it is exposed on Loongarch platform. The root cause
is that a zero length skb (skb->len == 0) was put on the queue.

This zero length skb is a TCP FIN packet, which was sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/e3a16eacdc6740658ee02a33489b1b9d4912f378.1719992715.git.tanggeliang@kylinos.cn
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Jul 11, 2024
@saschahauer
wifi: mwifiex: Do not return unused priv in mwifiex_get_priv_by_id()
c145eea 
mwifiex_get_priv_by_id() returns the priv pointer corresponding to
the bss_num and bss_type, but without checking if the priv is actually
currently in use.
Unused priv pointers do not have a wiphy attached to them which can
lead to NULL pointer dereferences further down the callstack.  Fix
this by returning only used priv pointers which have priv->bss_mode
set to something else than NL80211_IFTYPE_UNSPECIFIED.

Said NULL pointer dereference happened when an Accesspoint was started
with wpa_supplicant -i mlan0 with this config:

network={
        ssid="somessid"
        mode=2
        frequency=2412
        key_mgmt=WPA-PSK WPA-PSK-SHA256
        proto=RSN
        group=CCMP
        pairwise=CCMP
        psk="12345678"
}

When waiting for the AP to be established, interrupting wpa_supplicant
with <ctrl-c> and starting it again this happens:

| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000140
| 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=0000000046d96000
| [0000000000000140] pgd=0000000000000000, p4d=0000000000000000
| Internal error: Oops: 0000000096000004 [kernel-patches#1] PREEMPT SMP
| Modules linked in: caam_jr caamhash_desc spidev caamalg_desc crypto_engine authenc libdes mwifiex_sdio
+mwifiex crct10dif_ce cdc_acm onboard_usb_hub fsl_imx8_ddr_perf imx8m_ddrc rtc_ds1307 lm75 rtc_snvs
+imx_sdma caam imx8mm_thermal spi_imx error imx_cpufreq_dt fuse ip_tables x_tables ipv6
| CPU: 0 PID: 8 Comm: kworker/0:1 Not tainted 6.9.0-00007-g937242013fce-dirty kernel-patches#18
| Hardware name: somemachine (DT)
| Workqueue: events sdio_irq_work
| pstate: 00000005 (nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : mwifiex_get_cfp+0xd8/0x15c [mwifiex]
| lr : mwifiex_get_cfp+0x34/0x15c [mwifiex]
| sp : ffff8000818b3a70
| x29: ffff8000818b3a70 x28: ffff000006bfd8a5 x27: 0000000000000004
| x26: 000000000000002c x25: 0000000000001511 x24: 0000000002e86bc9
| x23: ffff000006bfd996 x22: 0000000000000004 x21: ffff000007bec000
| x20: 000000000000002c x19: 0000000000000000 x18: 0000000000000000
| x17: 000000040044ffff x16: 00500072b5503510 x15: ccc283740681e517
| x14: 0201000101006d15 x13: 0000000002e8ff43 x12: 002c01000000ffb1
| x11: 0100000000000000 x10: 02e8ff43002c0100 x9 : 0000ffb100100157
| x8 : ffff000003d20000 x7 : 00000000000002f1 x6 : 00000000ffffe124
| x5 : 0000000000000001 x4 : 0000000000000003 x3 : 0000000000000000
| x2 : 0000000000000000 x1 : 0001000000011001 x0 : 0000000000000000
| Call trace:
|  mwifiex_get_cfp+0xd8/0x15c [mwifiex]
|  mwifiex_parse_single_response_buf+0x1d0/0x504 [mwifiex]
|  mwifiex_handle_event_ext_scan_report+0x19c/0x2f8 [mwifiex]
|  mwifiex_process_sta_event+0x298/0xf0c [mwifiex]
|  mwifiex_process_event+0x110/0x238 [mwifiex]
|  mwifiex_main_process+0x428/0xa44 [mwifiex]
|  mwifiex_sdio_interrupt+0x64/0x12c [mwifiex_sdio]
|  process_sdio_pending_irqs+0x64/0x1b8
|  sdio_irq_work+0x4c/0x7c
|  process_one_work+0x148/0x2a0
|  worker_thread+0x2fc/0x40c
|  kthread+0x110/0x114
|  ret_from_fork+0x10/0x20
| Code: a94153f3 a8c37bfd d50323bf d65f03c0 (f940a000)
| ---[ end trace 0000000000000000 ]---

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://patch.msgid.link/20240703072409.556618-1-s.hauer@pengutronix.de
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Sep 6, 2024
@GeHao01994 @akpm00
codetag: debug: mark codetags for poisoned page as empty
5e9784e 
When PG_hwpoison pages are freed they are treated differently in
free_pages_prepare() and instead of being released they are isolated.

Page allocation tag counters are decremented at this point since the page
is considered not in use.  Later on when such pages are released by
unpoison_memory(), the allocation tag counters will be decremented again
and the following warning gets reported:

[  113.930443][ T3282] ------------[ cut here ]------------
[  113.931105][ T3282] alloc_tag was not set
[  113.931576][ T3282] WARNING: CPU: 2 PID: 3282 at ./include/linux/alloc_tag.h:130 pgalloc_tag_sub.part.66+0x154/0x164
[  113.932866][ T3282] Modules linked in: hwpoison_inject fuse ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute ip6table_nat ip6table_man4
[  113.941638][ T3282] CPU: 2 UID: 0 PID: 3282 Comm: madvise11 Kdump: loaded Tainted: G        W          6.11.0-rc4-dirty #18
[  113.943003][ T3282] Tainted: [W]=WARN
[  113.943453][ T3282] Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022
[  113.944378][ T3282] pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  113.945319][ T3282] pc : pgalloc_tag_sub.part.66+0x154/0x164
[  113.946016][ T3282] lr : pgalloc_tag_sub.part.66+0x154/0x164
[  113.946706][ T3282] sp : ffff800087093a10
[  113.947197][ T3282] x29: ffff800087093a10 x28: ffff0000d7a9d400 x27: ffff80008249f0a0
[  113.948165][ T3282] x26: 0000000000000000 x25: ffff80008249f2b0 x24: 0000000000000000
[  113.949134][ T3282] x23: 0000000000000001 x22: 0000000000000001 x21: 0000000000000000
[  113.950597][ T3282] x20: ffff0000c08fcad8 x19: ffff80008251e000 x18: ffffffffffffffff
[  113.952207][ T3282] x17: 0000000000000000 x16: 0000000000000000 x15: ffff800081746210
[  113.953161][ T3282] x14: 0000000000000000 x13: 205d323832335420 x12: 5b5d353031313339
[  113.954120][ T3282] x11: ffff800087093500 x10: 000000000000005d x9 : 00000000ffffffd0
[  113.955078][ T3282] x8 : 7f7f7f7f7f7f7f7f x7 : ffff80008236ba90 x6 : c0000000ffff7fff
[  113.956036][ T3282] x5 : ffff000b34bf4dc8 x4 : ffff8000820aba90 x3 : 0000000000000001
[  113.956994][ T3282] x2 : ffff800ab320f000 x1 : 841d1e35ac932e00 x0 : 0000000000000000
[  113.957962][ T3282] Call trace:
[  113.958350][ T3282]  pgalloc_tag_sub.part.66+0x154/0x164
[  113.959000][ T3282]  pgalloc_tag_sub+0x14/0x1c
[  113.959539][ T3282]  free_unref_page+0xf4/0x4b8
[  113.960096][ T3282]  __folio_put+0xd4/0x120
[  113.960614][ T3282]  folio_put+0x24/0x50
[  113.961103][ T3282]  unpoison_memory+0x4f0/0x5b0
[  113.961678][ T3282]  hwpoison_unpoison+0x30/0x48 [hwpoison_inject]
[  113.962436][ T3282]  simple_attr_write_xsigned.isra.34+0xec/0x1cc
[  113.963183][ T3282]  simple_attr_write+0x38/0x48
[  113.963750][ T3282]  debugfs_attr_write+0x54/0x80
[  113.964330][ T3282]  full_proxy_write+0x68/0x98
[  113.964880][ T3282]  vfs_write+0xdc/0x4d0
[  113.965372][ T3282]  ksys_write+0x78/0x100
[  113.965875][ T3282]  __arm64_sys_write+0x24/0x30
[  113.966440][ T3282]  invoke_syscall+0x7c/0x104
[  113.966984][ T3282]  el0_svc_common.constprop.1+0x88/0x104
[  113.967652][ T3282]  do_el0_svc+0x2c/0x38
[  113.968893][ T3282]  el0_svc+0x3c/0x1b8
[  113.969379][ T3282]  el0t_64_sync_handler+0x98/0xbc
[  113.969980][ T3282]  el0t_64_sync+0x19c/0x1a0
[  113.970511][ T3282] ---[ end trace 0000000000000000 ]---

To fix this, clear the page tag reference after the page got isolated
and accounted for.

Link: https://lkml.kernel.org/r/20240825163649.33294-1-hao.ge@linux.dev
Fixes: d224eb0 ("codetag: debug: mark codetags for reserved pages as empty")
Signed-off-by: Hao Ge <gehao@kylinos.cn>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hao Ge <gehao@kylinos.cn>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: <stable@vger.kernel.org>	[6.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Sep 23, 2024
@captain5050 @acmel
perf hist: Fix reference counting of branch_info
b2f70c9 
iter_finish_branch_entry() doesn't put the branch_info from/to map
elements creating memory leaks. This can be seen with:

```
$ perf record -e cycles -b perf test -w noploop
$ perf report -D
...
Direct leak of 984344 byte(s) in 123043 object(s) allocated from:
    #0 0x7fb2654f3bd7 in malloc libsanitizer/asan/asan_malloc_linux.cpp:69
    #1 0x564d3400d10b in map__get util/map.h:186
    #2 0x564d3400d10b in ip__resolve_ams util/machine.c:1981
    #3 0x564d34014d81 in sample__resolve_bstack util/machine.c:2151
    #4 0x564d34094790 in iter_prepare_branch_entry util/hist.c:898
    #5 0x564d34098fa4 in hist_entry_iter__add util/hist.c:1238
    #6 0x564d33d1f0c7 in process_sample_event tools/perf/builtin-report.c:334
    #7 0x564d34031eb7 in perf_session__deliver_event util/session.c:1655
    #8 0x564d3403ba52 in do_flush util/ordered-events.c:245
    #9 0x564d3403ba52 in __ordered_events__flush util/ordered-events.c:324
    #10 0x564d3402d32e in perf_session__process_user_event util/session.c:1708
    #11 0x564d34032480 in perf_session__process_event util/session.c:1877
    #12 0x564d340336ad in reader__read_event util/session.c:2399
    #13 0x564d34033fdc in reader__process_events util/session.c:2448
    #14 0x564d34033fdc in __perf_session__process_events util/session.c:2495
    #15 0x564d34033fdc in perf_session__process_events util/session.c:2661
    #16 0x564d33d27113 in __cmd_report tools/perf/builtin-report.c:1065
    #17 0x564d33d27113 in cmd_report tools/perf/builtin-report.c:1805
    #18 0x564d33e0ccb7 in run_builtin tools/perf/perf.c:350
    #19 0x564d33e0d45e in handle_internal_command tools/perf/perf.c:403
    #20 0x564d33cdd827 in run_argv tools/perf/perf.c:447
    #21 0x564d33cdd827 in main tools/perf/perf.c:561
...
```

Clearing up the map_symbols properly creates maps reference count
issues so resolve those. Resolving this issue doesn't improve peak
heap consumption for the test above.

Committer testing:

  $ sudo dnf install libasan
  $ make -k CORESIGHT=1 EXTRA_CFLAGS="-fsanitize=address" CC=clang O=/tmp/build/$(basename $PWD)/ -C tools/perf install-bin

Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sun Haiyong <sunhaiyong@loongson.cn>
Cc: Yanteng Si <siyanteng@loongson.cn>
Link: https://lore.kernel.org/r/20240807065136.1039977-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Sep 27, 2024
@gregkh
usb: dwc2: Adjust the timing of USB Driver Interrupt Registration in …
4058c39 
…the Crashkernel Scenario

The issue is that before entering the crash kernel, the DWC USB controller
did not perform operations such as resetting the interrupt mask bits.
After entering the crash kernel,before the USB interrupt handler
registration was completed while loading the DWC USB driver,an GINTSTS_SOF
interrupt was received.This triggered the misroute_irq process within the
GIC handling framework,ultimately leading to the misrouting of the
interrupt,causing it to be handled by the wrong interrupt handler
and resulting in the issue.

Summary:In a scenario where the kernel triggers a panic and enters
the crash kernel,it is necessary to ensure that the interrupt mask
bit is not enabled before the interrupt registration is complete.
If an interrupt reaches the CPU at this moment,it will certainly
not be handled correctly,especially in cases where this interrupt
is reported frequently.

Please refer to the Crashkernel dmesg information as follows
(the message on line 3 was added before devm_request_irq is
called by the dwc2_driver_probe function):
[    5.866837][    T1] dwc2 JMIC0010:01: supply vusb_d not found, using dummy regulator
[    5.874588][    T1] dwc2 JMIC0010:01: supply vusb_a not found, using dummy regulator
[    5.882335][    T1] dwc2 JMIC0010:01: before devm_request_irq  irq: [71], gintmsk[0xf300080e], gintsts[0x04200009]
[    5.892686][    C0] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.10.0-jmnd1.2_RC kernel-patches#18
[    5.900327][    C0] Hardware name: CMSS HyperCard4-25G/HyperCard4-25G, BIOS 1.6.4 Jul  8 2024
[    5.908836][    C0] Call trace:
[    5.911965][    C0]  dump_backtrace+0x0/0x1f0
[    5.916308][    C0]  show_stack+0x20/0x30
[    5.920304][    C0]  dump_stack+0xd8/0x140
[    5.924387][    C0]  pcie_xxx_handler+0x3c/0x1d8
[    5.930121][    C0]  __handle_irq_event_percpu+0x64/0x1e0
[    5.935506][    C0]  handle_irq_event+0x80/0x1d0
[    5.940109][    C0]  try_one_irq+0x138/0x174
[    5.944365][    C0]  misrouted_irq+0x134/0x140
[    5.948795][    C0]  note_interrupt+0x1d0/0x30c
[    5.953311][    C0]  handle_irq_event+0x13c/0x1d0
[    5.958001][    C0]  handle_fasteoi_irq+0xd4/0x260
[    5.962779][    C0]  __handle_domain_irq+0x88/0xf0
[    5.967555][    C0]  gic_handle_irq+0x9c/0x2f0
[    5.971985][    C0]  el1_irq+0xb8/0x140
[    5.975807][    C0]  __setup_irq+0x3dc/0x7cc
[    5.980064][    C0]  request_threaded_irq+0xf4/0x1b4
[    5.985015][    C0]  devm_request_threaded_irq+0x80/0x100
[    5.990400][    C0]  dwc2_driver_probe+0x1b8/0x6b0
[    5.995178][    C0]  platform_drv_probe+0x5c/0xb0
[    5.999868][    C0]  really_probe+0xf8/0x51c
[    6.004125][    C0]  driver_probe_device+0xfc/0x170
[    6.008989][    C0]  device_driver_attach+0xc8/0xd0
[    6.013853][    C0]  __driver_attach+0xe8/0x1b0
[    6.018369][    C0]  bus_for_each_dev+0x7c/0xdc
[    6.022886][    C0]  driver_attach+0x2c/0x3c
[    6.027143][    C0]  bus_add_driver+0xdc/0x240
[    6.031573][    C0]  driver_register+0x80/0x13c
[    6.036090][    C0]  __platform_driver_register+0x50/0x5c
[    6.041476][    C0]  dwc2_platform_driver_init+0x24/0x30
[    6.046774][    C0]  do_one_initcall+0x50/0x25c
[    6.051291][    C0]  do_initcall_level+0xe4/0xfc
[    6.055894][    C0]  do_initcalls+0x80/0xa4
[    6.060064][    C0]  kernel_init_freeable+0x198/0x240
[    6.065102][    C0]  kernel_init+0x1c/0x12c

Signed-off-by: Shawn Shao <shawn.shao@jaguarmicro.com>
Link: https://lore.kernel.org/r/20240830031709.134-1-shawn.shao@jaguarmicro.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Oct 25, 2024
@maqiao-mq @mhiramat
uprobe: avoid out-of-bounds memory access of fetching args
373b933 
Uprobe needs to fetch args into a percpu buffer, and then copy to ring
buffer to avoid non-atomic context problem.

Sometimes user-space strings, arrays can be very large, but the size of
percpu buffer is only page size. And store_trace_args() won't check
whether these data exceeds a single page or not, caused out-of-bounds
memory access.

It could be reproduced by following steps:
1. build kernel with CONFIG_KASAN enabled
2. save follow program as test.c

```
\#include <stdio.h>
\#include <stdlib.h>
\#include <string.h>

// If string length large than MAX_STRING_SIZE, the fetch_store_strlen()
// will return 0, cause __get_data_size() return shorter size, and
// store_trace_args() will not trigger out-of-bounds access.
// So make string length less than 4096.
\#define STRLEN 4093

void generate_string(char *str, int n)
{
    int i;
    for (i = 0; i < n; ++i)
    {
        char c = i % 26 + 'a';
        str[i] = c;
    }
    str[n-1] = '\0';
}

void print_string(char *str)
{
    printf("%s\n", str);
}

int main()
{
    char tmp[STRLEN];

    generate_string(tmp, STRLEN);
    print_string(tmp);

    return 0;
}
```
3. compile program
`gcc -o test test.c`

4. get the offset of `print_string()`
```
objdump -t test | grep -w print_string
0000000000401199 g     F .text  000000000000001b              print_string
```

5. configure uprobe with offset 0x1199
```
off=0x1199

cd /sys/kernel/debug/tracing/
echo "p /root/test:${off} arg1=+0(%di):ustring arg2=\$comm arg3=+0(%di):ustring"
 > uprobe_events
echo 1 > events/uprobes/enable
echo 1 > tracing_on
```

6. run `test`, and kasan will report error.
==================================================================
BUG: KASAN: use-after-free in strncpy_from_user+0x1d6/0x1f0
Write of size 8 at addr ffff88812311c004 by task test/499CPU: 0 UID: 0 PID: 499 Comm: test Not tainted 6.12.0-rc3+ #18
Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x55/0x70
 print_address_description.constprop.0+0x27/0x310
 kasan_report+0x10f/0x120
 ? strncpy_from_user+0x1d6/0x1f0
 strncpy_from_user+0x1d6/0x1f0
 ? rmqueue.constprop.0+0x70d/0x2ad0
 process_fetch_insn+0xb26/0x1470
 ? __pfx_process_fetch_insn+0x10/0x10
 ? _raw_spin_lock+0x85/0xe0
 ? __pfx__raw_spin_lock+0x10/0x10
 ? __pte_offset_map+0x1f/0x2d0
 ? unwind_next_frame+0xc5f/0x1f80
 ? arch_stack_walk+0x68/0xf0
 ? is_bpf_text_address+0x23/0x30
 ? kernel_text_address.part.0+0xbb/0xd0
 ? __kernel_text_address+0x66/0xb0
 ? unwind_get_return_address+0x5e/0xa0
 ? __pfx_stack_trace_consume_entry+0x10/0x10
 ? arch_stack_walk+0xa2/0xf0
 ? _raw_spin_lock_irqsave+0x8b/0xf0
 ? __pfx__raw_spin_lock_irqsave+0x10/0x10
 ? depot_alloc_stack+0x4c/0x1f0
 ? _raw_spin_unlock_irqrestore+0xe/0x30
 ? stack_depot_save_flags+0x35d/0x4f0
 ? kasan_save_stack+0x34/0x50
 ? kasan_save_stack+0x24/0x50
 ? mutex_lock+0x91/0xe0
 ? __pfx_mutex_lock+0x10/0x10
 prepare_uprobe_buffer.part.0+0x2cd/0x500
 uprobe_dispatcher+0x2c3/0x6a0
 ? __pfx_uprobe_dispatcher+0x10/0x10
 ? __kasan_slab_alloc+0x4d/0x90
 handler_chain+0xdd/0x3e0
 handle_swbp+0x26e/0x3d0
 ? __pfx_handle_swbp+0x10/0x10
 ? uprobe_pre_sstep_notifier+0x151/0x1b0
 irqentry_exit_to_user_mode+0xe2/0x1b0
 asm_exc_int3+0x39/0x40
RIP: 0033:0x401199
Code: 01 c2 0f b6 45 fb 88 02 83 45 fc 01 8b 45 fc 3b 45 e4 7c b7 8b 45 e4 48 98 48 8d 50 ff 48 8b 45 e8 48 01 d0 ce
RSP: 002b:00007ffdf00576a8 EFLAGS: 00000206
RAX: 00007ffdf00576b0 RBX: 0000000000000000 RCX: 0000000000000ff2
RDX: 0000000000000ffc RSI: 0000000000000ffd RDI: 00007ffdf00576b0
RBP: 00007ffdf00586b0 R08: 00007feb2f9c0d20 R09: 00007feb2f9c0d20
R10: 0000000000000001 R11: 0000000000000202 R12: 0000000000401040
R13: 00007ffdf0058780 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

This commit enforces the buffer's maxlen less than a page-size to avoid
store_trace_args() out-of-memory access.

Link: https://lore.kernel.org/all/20241015060148.1108331-1-mqaio@linux.alibaba.com/

Fixes: dcad1a2 ("tracing/uprobes: Fetch args before reserving a ring buffer")
Signed-off-by: Qiao Ma <mqaio@linux.alibaba.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
kuba-moo pushed a commit to linux-netdev/testing-bpf-ci that referenced this pull request Nov 1, 2024
@broonie
ASoC: qcom: sdm845: add missing soundwire runtime stream alloc
d0e806b 
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 [kernel-patches#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 kernel-patches#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, kernel-patches#16]
    6118:       a9025bf5        stp     x21, x22, [sp, kernel-patches#32]
    611c:       aa0103f6        mov     x22, x1
    6120:       2a0303f5        mov     w21, w3
    6124:       a90363f7        stp     x23, x24, [sp, kernel-patches#48]
    6128:       aa0003f8        mov     x24, x0
    612c:       aa0203f7        mov     x23, x2
    6130:       a9046bf9        stp     x25, x26, [sp, kernel-patches#64]
    6134:       aa0403f9        mov     x25, x4        <-- x4 copied to x25
    6138:       a90573fb        stp     x27, x28, [sp, kernel-patches#80]
    613c:       aa0403fb        mov     x27, x4
    6140:       f9418400        ldr     x0, [x0, kernel-patches#776]
    6144:       9100e000        add     x0, x0, #0x38
    6148:       94000000        bl      0 <mutex_lock>
    614c:       f8420f22        ldr     x2, [x25, kernel-patches#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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