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perf tools: Fix crash on synthesizing the unit

PATCH In review Jiri Olsa 3 participants 3 messages Nov 12, 2018 – Nov 21, 2018 perf events

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Jiri Olsa

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PATCH 1/1 perf tools: Fix crash on synthesizing the unit

Adam reported a record command crash for simple session like:

  $ perf record -e cpu-clock ls

with following backtrace:

Program received signal SIGSEGV, Segmentation fault.
3543 ev = event_update_event__new(size + 1, PERF_EVENT_UPDATE__UNIT, evsel->id[0]);
(gdb) bt

  #0  perf_event__synthesize_event_update_unit
  #1  0x000000000051e469 in perf_event__synthesize_extra_attr
  #2  0x00000000004445cb in record__synthesize
  #3  0x0000000000444bc5 in __cmd_record

...

We synthesize an update event that needs to touch the evsel id array, which is not defined at that time. Fixing this by forcing the id allocation for events with their unit defined.

Reflecting possible read_format ID bit in the attr tests.

Cc Adam Lee <[email protected]>
Reported-by Yongxin Liu <[email protected]>

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201477

Fixes bfd8f72c2778 ("perf record: Synthesize unit/scale/... in event update")
Link http://lkml.kernel.org/n/[email protected] open here
Signed-off-by Jiri Olsa <[email protected]>
---
 tools/perf/tests/attr/base-record | 2 +-
 tools/perf/util/evsel.c           | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
tools/perf/tests/attr/base-record +1 -1
index 37940665f736..efd0157b9d22 100644
@@ -9,7 +9,7 @@ size=112
 config=0
 sample_period=*
 sample_type=263
-read_format=0
+read_format=0|4
 disabled=1
 inherit=1
 pinned=0
tools/perf/util/evsel.c +1 -1
index d37bb1566cd9..dbc0466db368 100644
@@ -1092,7 +1092,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts,
 		attr->exclude_user   = 1;
 	}
 
-	if (evsel->own_cpus)
+	if (evsel->own_cpus || evsel->unit)
 		evsel->attr.read_format |= PERF_FORMAT_ID;
 
 	/*
Signature · 1 line
2.17.2
maintainer
#1 lore raw

Em Mon, Nov 12, 2018 at 02:00:12PM +0100, Jiri Olsa escreveu:

Quoted 2 lines

Adam reported a record command crash for simple session like:

  $ perf record -e cpu-clock ls

Thanks, tested, confirmed it fixes the problem, applied.

- Arnaldo

Quoted 56 lines

with following backtrace:

Program received signal SIGSEGV, Segmentation fault.
3543 ev = event_update_event__new(size + 1, PERF_EVENT_UPDATE__UNIT, evsel->id[0]);
(gdb) bt

  #0  perf_event__synthesize_event_update_unit
  #1  0x000000000051e469 in perf_event__synthesize_extra_attr
  #2  0x00000000004445cb in record__synthesize
  #3  0x0000000000444bc5 in __cmd_record

...

We synthesize an update event that needs to touch the evsel id array, which is not defined at that time. Fixing this by forcing the id allocation for events with their unit defined.

Reflecting possible read_format ID bit in the attr tests.

Cc Adam Lee <[email protected]>
Reported-by Yongxin Liu <[email protected]>

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201477

Fixes bfd8f72c2778 ("perf record: Synthesize unit/scale/... in event update")
Link http://lkml.kernel.org/n/[email protected] open here
Signed-off-by Jiri Olsa <[email protected]>
---
 tools/perf/tests/attr/base-record | 2 +-
 tools/perf/util/evsel.c           | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
tools/perf/tests/attr/base-record +1 -1
index 37940665f736..efd0157b9d22 100644
@@ -9,7 +9,7 @@ size=112
 config=0
 sample_period=*
 sample_type=263
-read_format=0
+read_format=0|4
 disabled=1
 inherit=1
 pinned=0
tools/perf/util/evsel.c +1 -1
index d37bb1566cd9..dbc0466db368 100644
@@ -1092,7 +1092,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts,
 		attr->exclude_user   = 1;
 	}
 
-	if (evsel->own_cpus)
+	if (evsel->own_cpus || evsel->unit)
 		evsel->attr.read_format |= PERF_FORMAT_ID;
 
 	/*
Signature · 1 line
2.17.2
merge bot
#2 lore raw
In reply to Jiri Olsa
perf tools: Fix crash on synthesizing the unit
Commit-ID:  fb50c09e923870a358d68b0d58891bd145b8d7c7
Gitweb:     https://git.kernel.org/tip/fb50c09e923870a358d68b0d58891bd145b8d7c7
Author:     Jiri Olsa <[email protected]>
AuthorDate: Mon, 12 Nov 2018 14:00:12 +0100
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Mon, 12 Nov 2018 08:37:49 -0800

perf tools: Fix crash on synthesizing the unit

Adam reported a record command crash for simple session like:

  $ perf record -e cpu-clock ls

with following backtrace:

Program received signal SIGSEGV, Segmentation fault.
3543 ev = event_update_event__new(size + 1, PERF_EVENT_UPDATE__UNIT, evsel->id[0]);
(gdb) bt

  #0  perf_event__synthesize_event_update_unit
  #1  0x000000000051e469 in perf_event__synthesize_extra_attr
  #2  0x00000000004445cb in record__synthesize
  #3  0x0000000000444bc5 in __cmd_record

...

We synthesize an update event that needs to touch the evsel id array, which is not defined at that time. Fix this by forcing the id allocation for events with their unit defined.

Reflecting possible read_format ID bit in the attr tests.

Reported-by Yongxin Liu <[email protected]>
Signed-off-by Jiri Olsa <[email protected]>
Cc Adam Lee <[email protected]>
Cc Alexander Shishkin <[email protected]>
Cc Namhyung Kim <[email protected]>
Cc Peter Zijlstra <[email protected]>

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201477

Fixes bfd8f72c2778 ("perf record: Synthesize unit/scale/... in event update")
Link http://lkml.kernel.org/r/[email protected] open here
Signed-off-by Arnaldo Carvalho de Melo <[email protected]>
---
 tools/perf/tests/attr/base-record | 2 +-
 tools/perf/util/evsel.c           | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
tools/perf/tests/attr/base-record +1 -1
index 37940665f736..efd0157b9d22 100644
@@ -9,7 +9,7 @@ size=112
 config=0
 sample_period=*
 sample_type=263
-read_format=0
+read_format=0|4
 disabled=1
 inherit=1
 pinned=0
tools/perf/util/evsel.c +1 -1
index d37bb1566cd9..dbc0466db368 100644
@@ -1092,7 +1092,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts,
 		attr->exclude_user   = 1;
 	}
 
-	if (evsel->own_cpus)
+	if (evsel->own_cpus || evsel->unit)
 		evsel->attr.read_format |= PERF_FORMAT_ID;
 
 	/*