Re: [PATCH AUTOSEL 4.14 112/127] perf parse-events: Fix incorrect conversion of 'if () free()' to 'zfree()'

Naresh Kamboju
2020-09-28T19:54:47Z

On Fri, 18 Sep 2020 at 08:00, Sasha Levin <sashal@kernel.org> wrote:
>
> From: Arnaldo Carvalho de Melo <acme@redhat.com>
>
> [ Upstream commit 7fcdccd4237724931d9773d1e3039bfe053a6f52 ]
>
> When applying a patch by Ian I incorrectly converted to zfree() an
> expression that involved testing some other struct member, not the one
> being freed, which lead to bugs reproduceable by:
>
> $ perf stat -e i/bs,tsc,L2/o sleep 1
> WARNING: multiple event parsing errors
> Segmentation fault (core dumped)
> $
>
> Fix it by restoring the test for pos->free_str before freeing
> pos->val.str, but continue using zfree(&pos->val.str) to set that member
> to NULL after freeing it.
>
> Reported-by: Ian Rogers <irogers@google.com>
> Fixes: e8dfb81838b1 ("perf parse-events: Fix memory leaks found on parse_events")
> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
> Cc: Andi Kleen <ak@linux.intel.com>
> Cc: clang-built-linux@googlegroups.com
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Leo Yan <leo.yan@linaro.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Stephane Eranian <eranian@google.com>
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> Signed-off-by: Sasha Levin <sashal@kernel.org>

stable rc 4.14 perf build broken.

> ---
> tools/perf/util/parse-events.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 2733cdfdf04c6..ba973bdfaa657 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -1258,7 +1258,8 @@ static int __parse_events_add_pmu(struct parse_events_state *parse_state,
>
> list_for_each_entry_safe(pos, tmp, &config_terms, list) {
> list_del_init(&pos->list);
> - zfree(&pos->val.str);
> + if (pos->free_str)
> + zfree(&pos->val.str);
> free(pos);
> }
> return -EINVAL;

util/parse-events.c: In function '__parse_events_add_pmu':
util/parse-events.c:1261:11: error: 'struct perf_evsel_config_term'
has no member named 'free_str'
if (pos->free_str)
^~
In file included from util/evlist.h:14:0,
from util/parse-events.c:10:
util/parse-events.c:1262:20: error: 'union <anonymous>' has no member
named 'str'
zfree(&pos->val.str);
^
util/util.h:27:29: note: in definition of macro 'zfree'
#define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
^~~
util/parse-events.c:1262:20: error: 'union <anonymous>' has no member
named 'str'
zfree(&pos->val.str);
^
util/util.h:27:36: note: in definition of macro 'zfree'
#define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
^~~

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>

full build link,
https://ci.linaro.org/view/lkft/job/openembedded-lkft-linux-stable-rc-4.14/DISTRO=lkft,MACHINE=intel-corei7-64,label=docker-lkft/938/consoleText

--
Linaro LKFT
https://lkft.linaro.org

> --
> 2.25.1
>