On Tue, Mar 16, 2021 at 09:24:53AM +0800, Jackie Liu wrote: > 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. > > v3->v4: > Fix memory leaks in more places
Acked-by: Jiri Olsa <[email protected]> thanks, jirka > > v2->v3: > free info_linear memory and move code above, don't do those extra btf > checks. > > Suggested-by: Jiri Olsa <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: Arnaldo Carvalho de Melo <[email protected]> > Cc: Mark Rutland <[email protected]> > Cc: Alexander Shishkin <[email protected]> > Cc: Namhyung Kim <[email protected]> > Signed-off-by: Jackie Liu <[email protected]> > --- > tools/perf/util/bpf-event.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c > index 57d58c81a5f8..cdecda1ddd36 100644 > --- a/tools/perf/util/bpf-event.c > +++ b/tools/perf/util/bpf-event.c > @@ -196,25 +196,32 @@ static int perf_event__synthesize_one_bpf_prog(struct > perf_session *session, > } > > if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) { > + free(info_linear); > pr_debug("%s: the kernel is too old, aborting\n", __func__); > return -2; > } > > info = &info_linear->info; > + if (!info->jited_ksyms) { > + free(info_linear); > + return -1; > + } > > /* number of ksyms, func_lengths, and tags should match */ > sub_prog_cnt = info->nr_jited_ksyms; > if (sub_prog_cnt != info->nr_prog_tags || > - sub_prog_cnt != info->nr_jited_func_lens) > + sub_prog_cnt != info->nr_jited_func_lens) { > + free(info_linear); > return -1; > + } > > /* check BTF func info support */ > if (info->btf_id && info->nr_func_info && info->func_info_rec_size) { > /* btf func info number should be same as sub_prog_cnt */ > if (sub_prog_cnt != info->nr_func_info) { > pr_debug("%s: mismatch in BPF sub program count and BTF > function info count, aborting\n", __func__); > - err = -1; > - goto out; > + free(info_linear); > + return -1; > } > if (btf__get_from_id(info->btf_id, &btf)) { > pr_debug("%s: failed to get BTF of id %u, aborting\n", > __func__, info->btf_id); > -- > 2.25.1 >
