From: Ian Rogers <irogers@google.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>,
Jiri Olsa <jolsa@kernel.org>,
Kan Liang <kan.liang@linux.intel.com>,
Namhyung Kim <namhyung@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-perf-users@vger.kernel.org
Subject: Re: [PATCH 1/1] perf callchain: Use zfree() to avoid possibly accessing dangling pointers
Date: Wed, 8 May 2024 16:40:15 -0700 [thread overview]
Message-ID: <CAP-5=fVz8a29_k9-j4LnJdAoqiXAREwg9g+owx5WZ0LhgT7yTQ@mail.gmail.com> (raw)
In-Reply-To: <ZjmcGobQ8E52EyjJ@x1>
On Mon, May 6, 2024 at 8:12 PM Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
>
> When freeing a->b it is good practice to set a->b to NULL using
> zfree(&a->b) so that when we have a bug where a reference to a freed 'a'
> pointer is kept somewhere, we can more quickly cause a segfault if some
> code tries to use a->b.
>
> Convert one such case in the callchain code.
>
> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Ian Rogers <irogers@google.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Kan Liang <kan.liang@linux.intel.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Thanks,
Ian
> ---
> tools/perf/util/callchain.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
> index 68feed8718096f78..1730b852a947400f 100644
> --- a/tools/perf/util/callchain.c
> +++ b/tools/perf/util/callchain.c
> @@ -606,7 +606,7 @@ fill_node(struct callchain_node *node, struct callchain_cursor *cursor)
> call->brtype_stat = zalloc(sizeof(*call->brtype_stat));
> if (!call->brtype_stat) {
> perror("not enough memory for the code path branch statistics");
> - free(call->brtype_stat);
> + zfree(&call->brtype_stat);
> return -ENOMEM;
> }
> }
> --
> 2.44.0
>
prev parent reply other threads:[~2024-05-08 23:40 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-07 3:12 [PATCH 1/1] perf callchain: Use zfree() to avoid possibly accessing dangling pointers Arnaldo Carvalho de Melo
2024-05-08 23:40 ` Ian Rogers [this message]
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