Messages in this thread Patch in this message | | | From | Jackie Liu <> | Subject | [PATCH v2] perf tools: perf_event_paranoid and kptr_restrict may crash on 'perf top' | Date | Thu, 25 Feb 2021 14:25:30 +0800 |
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After install the libelf-dev package and compiling perf, kptr_restrict=2 and perf_event_paranoid=3 will cause perf top to crash, because the value of /proc/kallsyms cannot be obtained, which leads to info->jited_ksyms == NULL. In order to solve this problem, Add a judgment before use.
Suggested-by: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Jackie Liu <liuyun01@kylinos.cn> --- tools/perf/util/bpf-event.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c index 57d58c81a5f8..b1ce2d189d37 100644 --- a/tools/perf/util/bpf-event.c +++ b/tools/perf/util/bpf-event.c @@ -225,6 +225,11 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session, perf_env__fetch_btf(env, info->btf_id, btf); } + if (!info->jited_ksyms) { + err = -1; + goto out; + } + /* Synthesize PERF_RECORD_KSYMBOL */ for (i = 0; i < sub_prog_cnt; i++) { __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens); -- 2.25.1
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