[PATCH] perf tools: Fix crash on buildid-list with namespace

[PATCH] perf tools: Fix crash on buildid-list with namespace

[Namhyung Kim]

Thomas reported that perf buildid-list gets a segfault due to NULL
pointer when he ran it on a data with namespace events.  It was because
the buildid_id__mark_dso_hit_ops lacks the namespace event handler and
perf_too__fill_default() didn't set it.

  Program received signal SIGSEGV, Segmentation fault.
  0x0000000000000000 in ?? ()
  Missing separate debuginfos, use: dnf debuginfo-install audit-libs-2.7.7-1.fc25.s390x bzip2-libs-1.0.6-21.fc25.s390x elfutils-libelf-0.169-1.fc25.s390x
  +elfutils-libs-0.169-1.fc25.s390x libcap-ng-0.7.8-1.fc25.s390x numactl-libs-2.0.11-2.ibm.fc25.s390x openssl-libs-1.1.0e-1.1.ibm.fc25.s390x perl-libs-5.24.1-386.fc25.s390x
  +python-libs-2.7.13-2.fc25.s390x slang-2.3.0-7.fc25.s390x xz-libs-5.2.3-2.fc25.s390x zlib-1.2.8-10.fc25.s390x
  (gdb) where
  #0  0x0000000000000000 in ?? ()
  #1  0x00000000010fad6a in machines__deliver_event (machines=<optimized out>, machines@entry=0x2c6fd18,
      evlist=<optimized out>, event=event@entry=0x3fffdf00470, sample=0x3ffffffe880, sample@entry=0x3ffffffe888,
      tool=tool@entry=0x1312968 <build_id.mark_dso_hit_ops>, file_offset=1136) at util/session.c:1287
  #2  0x00000000010fbf4e in perf_session__deliver_event (file_offset=1136, tool=0x1312968 <build_id.mark_dso_hit_ops>,
      sample=0x3ffffffe888, event=0x3fffdf00470, session=0x2c6fc30) at util/session.c:1340
  #3  perf_session__process_event (session=0x2c6fc30, session@entry=0x0, event=event@entry=0x3fffdf00470,
      file_offset=file_offset@entry=1136) at util/session.c:1522
  #4  0x00000000010fddde in __perf_session__process_events (file_size=11880, data_size=<optimized out>,
      data_offset=<optimized out>, session=0x0) at util/session.c:1899
  #5  perf_session__process_events (session=0x0, session@entry=0x2c6fc30) at util/session.c:1953
  #6  0x000000000103b2ac in perf_session__list_build_ids (with_hits=<optimized out>, force=<optimized out>)
      at builtin-buildid-list.c:83
  #7  cmd_buildid_list (argc=<optimized out>, argv=<optimized out>) at builtin-buildid-list.c:115
  #8  0x00000000010a026c in run_builtin (p=0x1311f78 <commands+24>, argc=argc@entry=2, argv=argv@entry=0x3fffffff3c0)
      at perf.c:296
  #9  0x000000000102bc00 in handle_internal_command (argv=<optimized out>, argc=2) at perf.c:348
  #10 run_argv (argcp=<synthetic pointer>, argv=<synthetic pointer>) at perf.c:392
  #11 main (argc=<optimized out>, argv=0x3fffffff3c0) at perf.c:536
  (gdb)

Fix it by adding a stub event handler for namespace event.

Reported-and-Tested-by: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/util/session.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index a7ebd9fe8e40..76ab0709a20c 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -374,6 +374,8 @@ void perf_tool__fill_defaults(struct perf_tool *tool)
 		tool->mmap2 = process_event_stub;
 	if (tool->comm == NULL)
 		tool->comm = process_event_stub;
+	if (tool->namespaces == NULL)
+		tool->namespaces = process_event_stub;
 	if (tool->fork == NULL)
 		tool->fork = process_event_stub;
 	if (tool->exit == NULL)
-- 
2.14.2

Re: [PATCH] perf tools: Fix crash on buildid-list with namespace

[Arnaldo Carvalho de Melo]

Em Tue, Oct 17, 2017 at 10:29:00PM +0900, Namhyung Kim escreveu:
> Thomas reported that perf buildid-list gets a segfault due to NULL
> pointer when he ran it on a data with namespace events.  It was because
> the buildid_id__mark_dso_hit_ops lacks the namespace event handler and
> perf_too__fill_default() didn't set it.

In these cases, next time I suggest you add a Fixes: tag, so that the
stable@kernel.org guys can automatically figure out which kernels need
this fix, in this case:

Fixes: f3b3614a284d ("perf tools: Add PERF_RECORD_NAMESPACES to include namespaces related info")

The script I have for this even adds this CC line:

Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>

I'm adding it,

Thanks!

- Arnaldo
 
>   Program received signal SIGSEGV, Segmentation fault.
>   0x0000000000000000 in ?? ()
>   Missing separate debuginfos, use: dnf debuginfo-install audit-libs-2.7.7-1.fc25.s390x bzip2-libs-1.0.6-21.fc25.s390x elfutils-libelf-0.169-1.fc25.s390x
>   +elfutils-libs-0.169-1.fc25.s390x libcap-ng-0.7.8-1.fc25.s390x numactl-libs-2.0.11-2.ibm.fc25.s390x openssl-libs-1.1.0e-1.1.ibm.fc25.s390x perl-libs-5.24.1-386.fc25.s390x
>   +python-libs-2.7.13-2.fc25.s390x slang-2.3.0-7.fc25.s390x xz-libs-5.2.3-2.fc25.s390x zlib-1.2.8-10.fc25.s390x
>   (gdb) where
>   #0  0x0000000000000000 in ?? ()
>   #1  0x00000000010fad6a in machines__deliver_event (machines=<optimized out>, machines@entry=0x2c6fd18,
>       evlist=<optimized out>, event=event@entry=0x3fffdf00470, sample=0x3ffffffe880, sample@entry=0x3ffffffe888,
>       tool=tool@entry=0x1312968 <build_id.mark_dso_hit_ops>, file_offset=1136) at util/session.c:1287
>   #2  0x00000000010fbf4e in perf_session__deliver_event (file_offset=1136, tool=0x1312968 <build_id.mark_dso_hit_ops>,
>       sample=0x3ffffffe888, event=0x3fffdf00470, session=0x2c6fc30) at util/session.c:1340
>   #3  perf_session__process_event (session=0x2c6fc30, session@entry=0x0, event=event@entry=0x3fffdf00470,
>       file_offset=file_offset@entry=1136) at util/session.c:1522
>   #4  0x00000000010fddde in __perf_session__process_events (file_size=11880, data_size=<optimized out>,
>       data_offset=<optimized out>, session=0x0) at util/session.c:1899
>   #5  perf_session__process_events (session=0x0, session@entry=0x2c6fc30) at util/session.c:1953
>   #6  0x000000000103b2ac in perf_session__list_build_ids (with_hits=<optimized out>, force=<optimized out>)
>       at builtin-buildid-list.c:83
>   #7  cmd_buildid_list (argc=<optimized out>, argv=<optimized out>) at builtin-buildid-list.c:115
>   #8  0x00000000010a026c in run_builtin (p=0x1311f78 <commands+24>, argc=argc@entry=2, argv=argv@entry=0x3fffffff3c0)
>       at perf.c:296
>   #9  0x000000000102bc00 in handle_internal_command (argv=<optimized out>, argc=2) at perf.c:348
>   #10 run_argv (argcp=<synthetic pointer>, argv=<synthetic pointer>) at perf.c:392
>   #11 main (argc=<optimized out>, argv=0x3fffffff3c0) at perf.c:536
>   (gdb)
> 
> Fix it by adding a stub event handler for namespace event.
> 
> Reported-and-Tested-by: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/perf/util/session.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
> index a7ebd9fe8e40..76ab0709a20c 100644
> --- a/tools/perf/util/session.c
> +++ b/tools/perf/util/session.c
> @@ -374,6 +374,8 @@ void perf_tool__fill_defaults(struct perf_tool *tool)
>  		tool->mmap2 = process_event_stub;
>  	if (tool->comm == NULL)
>  		tool->comm = process_event_stub;
> +	if (tool->namespaces == NULL)
> +		tool->namespaces = process_event_stub;
>  	if (tool->fork == NULL)
>  		tool->fork = process_event_stub;
>  	if (tool->exit == NULL)
> -- 
> 2.14.2

Re: [PATCH] perf tools: Fix crash on buildid-list with namespace

[Namhyung Kim]

On Tue, Oct 17, 2017 at 11:05:55AM -0300, Arnaldo Carvalho de Melo wrote:
> Em Tue, Oct 17, 2017 at 10:29:00PM +0900, Namhyung Kim escreveu:
> > Thomas reported that perf buildid-list gets a segfault due to NULL
> > pointer when he ran it on a data with namespace events.  It was because
> > the buildid_id__mark_dso_hit_ops lacks the namespace event handler and
> > perf_too__fill_default() didn't set it.
> 
> In these cases, next time I suggest you add a Fixes: tag, so that the
> stable@kernel.org guys can automatically figure out which kernels need
> this fix, in this case:
> 
> Fixes: f3b3614a284d ("perf tools: Add PERF_RECORD_NAMESPACES to include namespaces related info")

Ah right, will add next time.

> 
> The script I have for this even adds this CC line:
> 
> Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
> 
> I'm adding it,

Thanks,
Namhyung

[tip:perf/urgent] perf buildid-list: Fix crash when processing PERF_RECORD_NAMESPACE

[tip-bot for Namhyung Kim]

Commit-ID:  7f0cd23615040b9e53bb4980c986b721cba08bbc
Gitweb:     https://git.kernel.org/tip/7f0cd23615040b9e53bb4980c986b721cba08bbc
Author:     Namhyung Kim <namhyung@kernel.org>
AuthorDate: Tue, 17 Oct 2017 22:29:00 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 17 Oct 2017 11:09:19 -0300

perf buildid-list: Fix crash when processing PERF_RECORD_NAMESPACE

Thomas reported that 'perf buildid-list' gets a SEGFAULT due to NULL
pointer deref when he ran it on a data with namespace events.  It was
because the buildid_id__mark_dso_hit_ops lacks the namespace event
handler and perf_too__fill_default() didn't set it.

  Program received signal SIGSEGV, Segmentation fault.
  0x0000000000000000 in ?? ()
  Missing separate debuginfos, use: dnf debuginfo-install audit-libs-2.7.7-1.fc25.s390x bzip2-libs-1.0.6-21.fc25.s390x elfutils-libelf-0.169-1.fc25.s390x
  +elfutils-libs-0.169-1.fc25.s390x libcap-ng-0.7.8-1.fc25.s390x numactl-libs-2.0.11-2.ibm.fc25.s390x openssl-libs-1.1.0e-1.1.ibm.fc25.s390x perl-libs-5.24.1-386.fc25.s390x
  +python-libs-2.7.13-2.fc25.s390x slang-2.3.0-7.fc25.s390x xz-libs-5.2.3-2.fc25.s390x zlib-1.2.8-10.fc25.s390x
  (gdb) where
  #0  0x0000000000000000 in ?? ()
  #1  0x00000000010fad6a in machines__deliver_event (machines=<optimized out>, machines@entry=0x2c6fd18,
      evlist=<optimized out>, event=event@entry=0x3fffdf00470, sample=0x3ffffffe880, sample@entry=0x3ffffffe888,
      tool=tool@entry=0x1312968 <build_id.mark_dso_hit_ops>, file_offset=1136) at util/session.c:1287
  #2  0x00000000010fbf4e in perf_session__deliver_event (file_offset=1136, tool=0x1312968 <build_id.mark_dso_hit_ops>,
      sample=0x3ffffffe888, event=0x3fffdf00470, session=0x2c6fc30) at util/session.c:1340
  #3  perf_session__process_event (session=0x2c6fc30, session@entry=0x0, event=event@entry=0x3fffdf00470,
      file_offset=file_offset@entry=1136) at util/session.c:1522
  #4  0x00000000010fddde in __perf_session__process_events (file_size=11880, data_size=<optimized out>,
      data_offset=<optimized out>, session=0x0) at util/session.c:1899
  #5  perf_session__process_events (session=0x0, session@entry=0x2c6fc30) at util/session.c:1953
  #6  0x000000000103b2ac in perf_session__list_build_ids (with_hits=<optimized out>, force=<optimized out>)
      at builtin-buildid-list.c:83
  #7  cmd_buildid_list (argc=<optimized out>, argv=<optimized out>) at builtin-buildid-list.c:115
  #8  0x00000000010a026c in run_builtin (p=0x1311f78 <commands+24>, argc=argc@entry=2, argv=argv@entry=0x3fffffff3c0)
      at perf.c:296
  #9  0x000000000102bc00 in handle_internal_command (argv=<optimized out>, argc=2) at perf.c:348
  #10 run_argv (argcp=<synthetic pointer>, argv=<synthetic pointer>) at perf.c:392
  #11 main (argc=<optimized out>, argv=0x3fffffff3c0) at perf.c:536
  (gdb)

Fix it by adding a stub event handler for namespace event.

Committer testing:

Further clarifying, plain using 'perf buildid-list' will not end up in a
SEGFAULT when processing a perf.data file with namespace info:

  # perf record -a --namespaces sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 2.024 MB perf.data (1058 samples) ]
  # perf buildid-list | wc -l
  38
  # perf buildid-list | head -5
  e2a171c7b905826fc8494f0711ba76ab6abbd604 /lib/modules/4.14.0-rc3+/build/vmlinux
  874840a02d8f8a31cedd605d0b8653145472ced3 /lib/modules/4.14.0-rc3+/kernel/arch/x86/kvm/kvm-intel.ko
  ea7223776730cd8a22f320040aae4d54312984bc /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/i915/i915.ko
  5961535e6732a8edb7f22b3f148bb2fa2e0be4b9 /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/drm.ko
  f045f54aa78cf1931cc893f78b6cbc52c72a8cb1 /usr/lib64/libc-2.25.so
  #

It is only when one asks for checking what of those entries actually had
samples, i.e. when we use either -H or --with-hits, that we will process
all the PERF_RECORD_ events, and since tools/perf/builtin-buildid-list.c
neither explicitely set a perf_tool.namespaces() callback nor the
default stub was set that we end up, when processing a
PERF_RECORD_NAMESPACE record, causing a SEGFAULT:

  # perf buildid-list -H
  Segmentation fault (core dumped)
  ^C
  #

Reported-and-Tested-by: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Fixes: f3b3614a284d ("perf tools: Add PERF_RECORD_NAMESPACES to include namespaces related info")
Link: http://lkml.kernel.org/r/20171017132900.11043-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/session.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index a7ebd9f..76ab070 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -374,6 +374,8 @@ void perf_tool__fill_defaults(struct perf_tool *tool)
 		tool->mmap2 = process_event_stub;
 	if (tool->comm == NULL)
 		tool->comm = process_event_stub;
+	if (tool->namespaces == NULL)
+		tool->namespaces = process_event_stub;
 	if (tool->fork == NULL)
 		tool->fork = process_event_stub;
 	if (tool->exit == NULL)