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author | Jiri Olsa <jolsa@redhat.com> | 2018-02-16 15:36:19 +0300 |
---|---|---|
committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-02-16 20:55:47 +0300 |
commit | e3ebaa465136ecfedf9c6f4671df02bf625f8125 (patch) | |
tree | 082b010d645d001a8e71a0e77e9f3439f4a1c7f3 /tools/perf/util/hist.h | |
parent | b40982e8468b46b8f7f5bba5a7e541ec04a29d7d (diff) | |
download | linux-e3ebaa465136ecfedf9c6f4671df02bf625f8125.tar.xz |
perf report: Fix memory corruption in --branch-history mode --branch-history
Jin Yao reported memory corrupton in perf report with
branch info used for stack trace:
> Following command lines will cause perf crash.
> perf record -j call -g -a <application>
> perf report --branch-history
>
> *** Error in `perf': double free or corruption (!prev): 0x00000000104aa040 ***
> ======= Backtrace: =========
> /lib/x86_64-linux-gnu/libc.so.6(+0x77725)[0x7f6b37254725]
> /lib/x86_64-linux-gnu/libc.so.6(+0x7ff4a)[0x7f6b3725cf4a]
> /lib/x86_64-linux-gnu/libc.so.6(cfree+0x4c)[0x7f6b37260abc]
> perf[0x51b914]
> perf(hist_entry_iter__add+0x1e5)[0x51f305]
> perf[0x43cf01]
> perf[0x4fa3bf]
> perf[0x4fa923]
> perf[0x4fd396]
> perf[0x4f9614]
> perf(perf_session__process_events+0x89e)[0x4fc38e]
> perf(cmd_report+0x15d2)[0x43f202]
> perf[0x4a059f]
> perf(main+0x631)[0x427b71]
> /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0)[0x7f6b371fd830]
> perf(_start+0x29)[0x427d89]
For the cumulative output, we allocate the he_cache array based on the
--max-stack option value and populate it with data from 'callchain_cursor'.
The --max-stack option value does not ensure now the limit for number of
callchain_cursor nodes, so the cumulative iter code will allocate smaller array
than it's actually needed and cause above corruption.
I think the --max-stack limit does not apply here anyway, because we add
callchain data as normal hist entries, while the --max-stack control the limit
of single entry callchain depth.
Using the callchain_cursor.nr as he_cache array count to fix this. Also
removing struct hist_entry_iter::max_stack, because there's no longer any use
for it.
We need more fixes to ensure that the branch stack code follows properly the
logic of --max-stack, which is not the case at the moment.
Original-patch-by: Jin Yao <yao.jin@linux.intel.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Reported-by: Jin Yao <yao.jin@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180216123619.GA9945@krava
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/hist.h')
-rw-r--r-- | tools/perf/util/hist.h | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h index 02721b579746..e869cad4d89f 100644 --- a/tools/perf/util/hist.h +++ b/tools/perf/util/hist.h @@ -107,7 +107,6 @@ struct hist_entry_iter { int curr; bool hide_unresolved; - int max_stack; struct perf_evsel *evsel; struct perf_sample *sample; |