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authorJackie Liu <jackieliu2113@gmail.com>2021-03-16 09:24:53 +0800
committerArnaldo Carvalho de Melo <acme@redhat.com>2021-03-16 10:01:44 -0300
commit1a096ae46e21b73f83a581e617f76326c1de592d (patch)
treecd4a31171223f24b643605bb7fc2194d86ea8b27 /tools
parente40647762fb5881360874e08e03e972d58d63c42 (diff)
perf top: Fix BPF support related crash with perf_event_paranoid=3 + kptr_restrict
After installing the libelf-dev package and compiling perf, if we have kptr_restrict=2 and perf_event_paranoid=3 'perf top' will 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 check before use. Also plug some leaks on the error path. Suggested-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Jackie Liu <liuyun01@kylinos.cn> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: jackie liu <liuyun01@kylinos.cn> Link: http://lore.kernel.org/lkml/20210316012453.1156-1-liuyun01@kylinos.cn Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/util/bpf-event.c13
1 files 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);