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From:   Ian Rogers <irogers@google.com>
Date:   Thu, 3 Jun 2021 21:15:32 -0700
Message-ID: <CAP-5=fW5btkb9izxcUy+XgAQPCTRZAUMa4uQMUR_+N_d=17Mfg@mail.gmail.com>
Subject: Re: [PATCH] perf env: fix memory leak: free bpf_prog_info_linear
To:     Riccardo Mancini <rickyman7@gmail.com>
Cc:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>,
        linux-perf-users <linux-perf-users@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>
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On Wed, Jun 2, 2021 at 3:41 PM Riccardo Mancini <rickyman7@gmail.com> wrote:
>
> ASan reported a memory leak caused by info_linear not being
> deallocated. The info_linear was allocated during
> perf_event__synthesize_one_bpf_prog.
> This patch adds the corresponding free() when bpf_prog_info_node
> is freed in perf_env__purge_bpf.
>
> $ sudo ./perf record -- sleep 5
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.025 MB perf.data (8 samples) ]
>
> =================================================================
> ==297735==ERROR: LeakSanitizer: detected memory leaks
>
> Direct leak of 7688 byte(s) in 19 object(s) allocated from:
>     #0 0x4f420f in malloc (/home/user/linux/tools/perf/perf+0x4f420f)
>     #1 0xc06a74 in bpf_program__get_prog_info_linear /home/user/linux/tools/lib/bpf/libbpf.c:11113:16
>     #2 0xb426fe in perf_event__synthesize_one_bpf_prog /home/user/linux/tools/perf/util/bpf-event.c:191:16
>     #3 0xb42008 in perf_event__synthesize_bpf_events /home/user/linux/tools/perf/util/bpf-event.c:410:9
>     #4 0x594596 in record__synthesize /home/user/linux/tools/perf/builtin-record.c:1490:8
>     #5 0x58c9ac in __cmd_record /home/user/linux/tools/perf/builtin-record.c:1798:8
>     #6 0x58990b in cmd_record /home/user/linux/tools/perf/builtin-record.c:2901:8
>     #7 0x7b2a20 in run_builtin /home/user/linux/tools/perf/perf.c:313:11
>     #8 0x7b12ff in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8
>     #9 0x7b2583 in run_argv /home/user/linux/tools/perf/perf.c:409:2
>     #10 0x7b0d79 in main /home/user/linux/tools/perf/perf.c:539:3
>     #11 0x7fa357ef6b74 in __libc_start_main /usr/src/debug/glibc-2.33-8.fc34.x86_64/csu/../csu/libc-start.c:332:16
>
> Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>

Acked-by: Ian Rogers <irogers@google.com>

Thanks,
Ian

> ---
>  tools/perf/util/env.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
> index 9130f6fad8d54..bc5e4f294e9e9 100644
> --- a/tools/perf/util/env.c
> +++ b/tools/perf/util/env.c
> @@ -144,6 +144,7 @@ static void perf_env__purge_bpf(struct perf_env *env)
>                 node = rb_entry(next, struct bpf_prog_info_node, rb_node);
>                 next = rb_next(&node->rb_node);
>                 rb_erase(&node->rb_node, root);
> +               free(node->info_linear);
>                 free(node);
>         }
>
> --
> 2.31.1
>