linux-stable.git/tools, branch v4.9.243

perf intel-pt: Fix "context_switch event has no tid" error

2020-10-29T08:05:38+00:00

[ Upstream commit 7d537a8d2e76bc4fc71e34545ceaa463ac2cd928 ]

A context_switch event can have no tid because pids can be detached from
a task while the task is still running (in do_exit()). Note this won't
happen with per-task contexts because then tracing stops at
perf_event_exit_task()

If a task with no tid gets preempted, or a dying task gets preempted and
its parent releases it, when it subsequently gets switched back in,
Intel PT will not be able to determine what task is running and prints
an error "context_switch event has no tid". However, it is not really an
error because the task is in kernel space and the decoder can continue
to decode successfully. Fix by changing the error to be only a logged
message, and make allowance for tid == -1.

Example:

  Using 5.9-rc4 with Preemptible Kernel (Low-Latency Desktop) e.g.
  $ uname -r
  5.9.0-rc4
  $ grep PREEMPT .config
  # CONFIG_PREEMPT_NONE is not set
  # CONFIG_PREEMPT_VOLUNTARY is not set
  CONFIG_PREEMPT=y
  CONFIG_PREEMPT_COUNT=y
  CONFIG_PREEMPTION=y
  CONFIG_PREEMPT_RCU=y
  CONFIG_PREEMPT_NOTIFIERS=y
  CONFIG_DRM_I915_PREEMPT_TIMEOUT=640
  CONFIG_DEBUG_PREEMPT=y
  # CONFIG_PREEMPT_TRACER is not set
  # CONFIG_PREEMPTIRQ_DELAY_TEST is not set

Before:

  $ cat forkit.c

  #include 
  #include 
  #include 

  int main()
  {
          pid_t child;
          int status = 0;

          child = fork();
          if (child == 0)
                  return 123;
          wait(&status);
          return 0;
  }

  $ gcc -o forkit forkit.c
  $ sudo ~/bin/perf record --kcore -a -m,64M -e intel_pt/cyc/k &
  [1] 11016
  $ taskset 2 ./forkit
  $ sudo pkill perf
  $ [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 17.262 MB perf.data ]

  [1]+  Terminated              sudo ~/bin/perf record --kcore -a -m,64M -e intel_pt/cyc/k
  $ sudo ~/bin/perf script --show-task-events --show-switch-events --itrace=iqqe-o -C 1 --ns | grep -C 2 forkit
  context_switch event has no tid
           taskset 11019 [001] 66663.270045029:          1 instructions:k:  ffffffffb1d9f844 strnlen_user+0xb4 ([kernel.kallsyms])
           taskset 11019 [001] 66663.270201816:          1 instructions:k:  ffffffffb1a83121 unmap_page_range+0x561 ([kernel.kallsyms])
            forkit 11019 [001] 66663.270327553: PERF_RECORD_COMM exec: forkit:11019/11019
            forkit 11019 [001] 66663.270420028:          1 instructions:k:  ffffffffb1db9537 __clear_user+0x27 ([kernel.kallsyms])
            forkit 11019 [001] 66663.270648704:          1 instructions:k:  ffffffffb18829e6 do_user_addr_fault+0xf6 ([kernel.kallsyms])
            forkit 11019 [001] 66663.270833163:          1 instructions:k:  ffffffffb230a825 irqentry_exit_to_user_mode+0x15 ([kernel.kallsyms])
            forkit 11019 [001] 66663.271092359:          1 instructions:k:  ffffffffb1aea3d9 lock_page_memcg+0x9 ([kernel.kallsyms])
            forkit 11019 [001] 66663.271207092: PERF_RECORD_FORK(11020:11020):(11019:11019)
            forkit 11019 [001] 66663.271234775: PERF_RECORD_SWITCH_CPU_WIDE OUT          next pid/tid: 11020/11020
            forkit 11020 [001] 66663.271238407: PERF_RECORD_SWITCH_CPU_WIDE IN           prev pid/tid: 11019/11019
            forkit 11020 [001] 66663.271312066:          1 instructions:k:  ffffffffb1a88140 handle_mm_fault+0x10 ([kernel.kallsyms])
            forkit 11020 [001] 66663.271476225: PERF_RECORD_EXIT(11020:11020):(11019:11019)
            forkit 11020 [001] 66663.271497488: PERF_RECORD_SWITCH_CPU_WIDE OUT preempt  next pid/tid: 11019/11019
            forkit 11019 [001] 66663.271500523: PERF_RECORD_SWITCH_CPU_WIDE IN           prev pid/tid: 11020/11020
            forkit 11019 [001] 66663.271517241:          1 instructions:k:  ffffffffb24012cd error_entry+0x6d ([kernel.kallsyms])
            forkit 11019 [001] 66663.271664080: PERF_RECORD_EXIT(11019:11019):(1386:1386)

After:

  $ sudo ~/bin/perf script --show-task-events --show-switch-events --itrace=iqqe-o -C 1 --ns | grep -C 2 forkit
           taskset 11019 [001] 66663.270045029:          1 instructions:k:  ffffffffb1d9f844 strnlen_user+0xb4 ([kernel.kallsyms])
           taskset 11019 [001] 66663.270201816:          1 instructions:k:  ffffffffb1a83121 unmap_page_range+0x561 ([kernel.kallsyms])
            forkit 11019 [001] 66663.270327553: PERF_RECORD_COMM exec: forkit:11019/11019
            forkit 11019 [001] 66663.270420028:          1 instructions:k:  ffffffffb1db9537 __clear_user+0x27 ([kernel.kallsyms])
            forkit 11019 [001] 66663.270648704:          1 instructions:k:  ffffffffb18829e6 do_user_addr_fault+0xf6 ([kernel.kallsyms])
            forkit 11019 [001] 66663.270833163:          1 instructions:k:  ffffffffb230a825 irqentry_exit_to_user_mode+0x15 ([kernel.kallsyms])
            forkit 11019 [001] 66663.271092359:          1 instructions:k:  ffffffffb1aea3d9 lock_page_memcg+0x9 ([kernel.kallsyms])
            forkit 11019 [001] 66663.271207092: PERF_RECORD_FORK(11020:11020):(11019:11019)
            forkit 11019 [001] 66663.271234775: PERF_RECORD_SWITCH_CPU_WIDE OUT          next pid/tid: 11020/11020
            forkit 11020 [001] 66663.271238407: PERF_RECORD_SWITCH_CPU_WIDE IN           prev pid/tid: 11019/11019
            forkit 11020 [001] 66663.271312066:          1 instructions:k:  ffffffffb1a88140 handle_mm_fault+0x10 ([kernel.kallsyms])
            forkit 11020 [001] 66663.271476225: PERF_RECORD_EXIT(11020:11020):(11019:11019)
            forkit 11020 [001] 66663.271497488: PERF_RECORD_SWITCH_CPU_WIDE OUT preempt  next pid/tid: 11019/11019
            forkit 11019 [001] 66663.271500523: PERF_RECORD_SWITCH_CPU_WIDE IN           prev pid/tid: 11020/11020
            forkit 11019 [001] 66663.271517241:          1 instructions:k:  ffffffffb24012cd error_entry+0x6d ([kernel.kallsyms])
            forkit 11019 [001] 66663.271664080: PERF_RECORD_EXIT(11019:11019):(1386:1386)
            forkit 11019 [001] 66663.271688752: PERF_RECORD_SWITCH_CPU_WIDE OUT          next pid/tid:    -1/-1
               :-1    -1 [001] 66663.271692086: PERF_RECORD_SWITCH_CPU_WIDE IN           prev pid/tid: 11019/11019
                :-1    -1 [001] 66663.271707466:          1 instructions:k:  ffffffffb18eb096 update_load_avg+0x306 ([kernel.kallsyms])

Fixes: 86c2786994bd7c ("perf intel-pt: Add support for PERF_RECORD_SWITCH")
Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Yu-cheng Yu 
Link: http://lore.kernel.org/lkml/20200909084923.9096-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf top: Fix stdio interface input handling with glibc 2.28+

2020-10-14T07:48:15+00:00

commit 29b4f5f188571c112713c35cc87eefb46efee612 upstream.

Since glibc 2.28 when running 'perf top --stdio', input handling no
longer works, but hitting any key always just prints the "Mapped keys"
help text.

To fix it, call clearerr() in the display_thread() loop to clear any EOF
sticky errors, as instructed in the glibc NEWS file
(https://sourceware.org/git/?p=glibc.git;a=blob;f=NEWS):

 * All stdio functions now treat end-of-file as a sticky condition.  If you
   read from a file until EOF, and then the file is enlarged by another
   process, you must call clearerr or another function with the same effect
   (e.g. fseek, rewind) before you can read the additional data.  This
   corrects a longstanding C99 conformance bug.  It is most likely to affect
   programs that use stdio to read interactive input from a terminal.
   (Bug #1190.)

Signed-off-by: Tommi Rantala 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20200305083714.9381-2-tommi.t.rantala@nokia.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

objtool: Fix noreturn detection for ignored functions

2020-10-01T18:40:16+00:00

[ Upstream commit db6c6a0df840e3f52c84cc302cc1a08ba11a4416 ]

When a function is annotated with STACK_FRAME_NON_STANDARD, objtool
doesn't validate its code paths.  It also skips sibling call detection
within the function.

But sibling call detection is actually needed for the case where the
ignored function doesn't have any return instructions.  Otherwise
objtool naively marks the function as implicit static noreturn, which
affects the reachability of its callers, resulting in "unreachable
instruction" warnings.

Fix it by just enabling sibling call detection for ignored functions.
The 'insn->ignore' check in add_jump_destinations() is no longer needed
after

  e6da9567959e ("objtool: Don't use ignore flag for fake jumps").

Fixes the following warning:

  arch/x86/kvm/vmx/vmx.o: warning: objtool: vmx_handle_exit_irqoff()+0x142: unreachable instruction

which triggers on an allmodconfig with CONFIG_GCOV_KERNEL unset.

Reported-by: Linus Torvalds 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Borislav Petkov 
Acked-by: Linus Torvalds 
Link: https://lkml.kernel.org/r/5b1e2536cdbaa5246b60d7791b76130a74082c62.1599751464.git.jpoimboe@redhat.com
Signed-off-by: Sasha Levin

selftests/x86/syscall_nt: Clear weird flags after each test

2020-10-01T18:40:16+00:00

[ Upstream commit a61fa2799ef9bf6c4f54cf7295036577cececc72 ]

Clear the weird flags before logging to improve strace output --
logging results while, say, TF is set does no one any favors.

Signed-off-by: Andy Lutomirski 
Signed-off-by: Thomas Gleixner 
Link: https://lkml.kernel.org/r/907bfa5a42d4475b8245e18b67a04b13ca51ffdb.1593191971.git.luto@kernel.org
Signed-off-by: Sasha Levin

perf kcore_copy: Fix module map when there are no modules loaded

2020-10-01T18:40:14+00:00

[ Upstream commit 61f82e3fb697a8e85f22fdec786528af73dc36d1 ]

In the absence of any modules, no "modules" map is created, but there
are other executable pages to map, due to eBPF JIT, kprobe or ftrace.
Map them by recognizing that the first "module" symbol is not
necessarily from a module, and adjust the map accordingly.

Signed-off-by: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Borislav Petkov 
Cc: H. Peter Anvin 
Cc: Jiri Olsa 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Masami Hiramatsu 
Cc: Mathieu Poirier 
Cc: Peter Zijlstra 
Cc: Steven Rostedt (VMware) 
Cc: x86@kernel.org
Link: http://lore.kernel.org/lkml/20200512121922.8997-10-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf util: Fix memory leak of prefix_if_not_in

2020-10-01T18:40:14+00:00

[ Upstream commit 07e9a6f538cbeecaf5c55b6f2991416f873cdcbd ]

Need to free "str" before return when asprintf() failed to avoid memory
leak.

Signed-off-by: Xie XiuQi 
Cc: Alexander Shishkin 
Cc: Hongbo Yao 
Cc: Jiri Olsa 
Cc: Li Bin 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Link: http://lore.kernel.org/lkml/20200521133218.30150-4-liwei391@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

tools: gpio-hammer: Avoid potential overflow in main

2020-10-01T18:40:10+00:00

[ Upstream commit d1ee7e1f5c9191afb69ce46cc7752e4257340a31 ]

If '-o' was used more than 64 times in a single invocation of gpio-hammer,
this could lead to an overflow of the 'lines' array. This commit fixes
this by avoiding the overflow and giving a proper diagnostic back to the
user

Signed-off-by: Gabriel Ravier 
Signed-off-by: Bartosz Golaszewski 
Signed-off-by: Sasha Levin

perf test: Free formats for perf pmu parse test

2020-09-23T06:46:15+00:00

[ Upstream commit d26383dcb2b4b8629fde05270b4e3633be9e3d4b ]

The following leaks were detected by ASAN:

  Indirect leak of 360 byte(s) in 9 object(s) allocated from:
    #0 0x7fecc305180e in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10780e)
    #1 0x560578f6dce5 in perf_pmu__new_format util/pmu.c:1333
    #2 0x560578f752fc in perf_pmu_parse util/pmu.y:59
    #3 0x560578f6a8b7 in perf_pmu__format_parse util/pmu.c:73
    #4 0x560578e07045 in test__pmu tests/pmu.c:155
    #5 0x560578de109b in run_test tests/builtin-test.c:410
    #6 0x560578de109b in test_and_print tests/builtin-test.c:440
    #7 0x560578de401a in __cmd_test tests/builtin-test.c:661
    #8 0x560578de401a in cmd_test tests/builtin-test.c:807
    #9 0x560578e49354 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    #10 0x560578ce71a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    #11 0x560578ce71a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    #12 0x560578ce71a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    #13 0x7fecc2b7acc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: cff7f956ec4a1 ("perf tests: Move pmu tests into separate object")
Signed-off-by: Namhyung Kim 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Ian Rogers 
Cc: Mark Rutland 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lore.kernel.org/lkml/20200915031819.386559-12-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf record/stat: Explicitly call out event modifiers in the documentation

2020-09-12T09:47:32+00:00

commit e48a73a312ebf19cc3d72aa74985db25c30757c1 upstream.

Event modifiers are not mentioned in the perf record or perf stat
manpages.  Add them to orient new users more effectively by pointing
them to the perf list manpage for details.

Fixes: 2055fdaf8703 ("perf list: Document precise event sampling for AMD IBS")
Signed-off-by: Kim Phillips 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexey Budankov 
Cc: Ian Rogers 
Cc: Jin Yao 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Paul Clarke 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Tony Jones 
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200901215853.276234-1-kim.phillips@amd.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

selftests/powerpc: Purge extra count_pmc() calls of ebb selftests

2020-09-03T09:21:17+00:00

[ Upstream commit 3337bf41e0dd70b4064cdf60acdfcdc2d050066c ]

An extra count on ebb_state.stats.pmc_count[PMC_INDEX(pmc)] is being per-
formed when count_pmc() is used to reset PMCs on a few selftests. This
extra pmc_count can occasionally invalidate results, such as the ones from
cycles_test shown hereafter. The ebb_check_count() failed with an above
the upper limit error due to the extra value on ebb_state.stats.pmc_count.

Furthermore, this extra count is also indicated by extra PMC1 trace_log on
the output of the cycle test (as well as on pmc56_overflow_test):

==========
   ...
   [21]: counter = 8
   [22]: register SPRN_MMCR0 = 0x0000000080000080
   [23]: register SPRN_PMC1  = 0x0000000080000004
   [24]: counter = 9
   [25]: register SPRN_MMCR0 = 0x0000000080000080
   [26]: register SPRN_PMC1  = 0x0000000080000004
   [27]: counter = 10
   [28]: register SPRN_MMCR0 = 0x0000000080000080
   [29]: register SPRN_PMC1  = 0x0000000080000004
>> [30]: register SPRN_PMC1  = 0x000000004000051e
PMC1 count (0x280000546) above upper limit 0x2800003e8 (+0x15e)
[FAIL] Test FAILED on line 52
failure: cycles
==========

Signed-off-by: Desnes A. Nunes do Rosario 
Tested-by: Sachin Sant 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200626164737.21943-1-desnesn@linux.ibm.com
Signed-off-by: Sasha Levin