Messages in this thread Patch in this message | | | Date | Thu, 15 Jul 2021 16:20:24 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 01/20] perf nsinfo: fix refcounting |
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Em Thu, Jul 15, 2021 at 04:02:16PM -0300, Arnaldo Carvalho de Melo escreveu: > Em Thu, Jul 15, 2021 at 06:07:06PM +0200, Riccardo Mancini escreveu: > > ASan reports a memory leak of nsinfo during the execution of the perf > > test "31: Lookup mmap thread". > > The leak is caused by a refcounted variable being replaced without > > dropping the refcount.
> > This patch makes sure that the refcnt of nsinfo is decreased whenever > > a refcounted variable is replaced with a new value.
> So, there are multiple fixes in just one patch, I'll split it into > three, no need to resend.
> I'll try and check if finding Fixes: for the three is easy, that way > stable@vger.kernel.org will figure out which of the supported releases > need each of them.
The second is at the end of this message, and looking at it I think there is a problem with where this nsinfo reference is stored, it should be in the 'struct map', that is per-thread, not in the 'struct dso', that may be shared by multiple 'struct map's in different cgroups, so we can't set dso->nsinfo in map__new(), right? Kristen?
- Arnaldo
commit 280f3933661f9ca9563ed04ce82313fdbcbb8f75 Author: Riccardo Mancini <rickyman7@gmail.com> Date: Thu Jul 15 18:07:06 2021 +0200
perf map: Fix dso->nsinfo refcounting
ASan reports a memory leak of nsinfo during the execution of
# perf test "31: Lookup mmap thread"
The leak is caused by a refcounted variable being replaced without dropping the refcount.
This patch makes sure that the refcnt of nsinfo is decreased whenever a refcounted variable is replaced with a new value.
Signed-off-by: Riccardo Mancini <rickyman7@gmail.com> Fixes: bf2e710b3cb8445c ("perf maps: Lookup maps in both intitial mountns and inner mountns.") Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Krister Johansen <kjlx@templeofstupid.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lore.kernel.org/lkml/55223bc8821b34ccb01f92ef1401c02b6a32e61f.1626343282.git.rickyman7@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c index 8af693d9678cefe0..72e7f3616157ead4 100644 --- a/tools/perf/util/map.c +++ b/tools/perf/util/map.c @@ -192,6 +192,8 @@ struct map *map__new(struct machine *machine, u64 start, u64 len, if (!(prot & PROT_EXEC)) dso__set_loaded(dso); } + + nsinfo__put(dso->nsinfo); dso->nsinfo = nsi; if (build_id__is_defined(bid))
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