diff options
| author | Thomas Richter | 2021-04-21 14:04:00 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo | 2021-04-23 15:58:10 -0300 |
| commit | 671b60cb6a897a5b3832fe57657152f2c3995e25 (patch) | |
| tree | 28610ba75f44500ac3414fc709df491d5d76fc9a | |
| parent | b14585d9f18dc617e975815570fe836be656b1da (diff) | |
perf ftrace: Fix access to pid in array when setting a pid filter
Command 'perf ftrace -v -- ls' fails in s390 (at least 5.12.0rc6).
The root cause is a missing pointer dereference which causes an
array element address to be used as PID.
Fix this by extracting the PID.
Output before:
# ./perf ftrace -v -- ls
function_graph tracer is used
write '-263732416' to tracing/set_ftrace_pid failed: Invalid argument
failed to set ftrace pid
#
Output after:
./perf ftrace -v -- ls
function_graph tracer is used
# tracer: function_graph
#
# CPU DURATION FUNCTION CALLS
# | | | | | | |
4) | rcu_read_lock_sched_held() {
4) 0.552 us | rcu_lockdep_current_cpu_online();
4) 6.124 us | }
Reported-by: Alexander Schmidt <alexschm@de.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20210421120400.2126433-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/builtin-ftrace.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index d49448a1060c..87cb11a7a3ee 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -289,7 +289,7 @@ static int set_tracing_pid(struct perf_ftrace *ftrace) for (i = 0; i < perf_thread_map__nr(ftrace->evlist->core.threads); i++) { scnprintf(buf, sizeof(buf), "%d", - ftrace->evlist->core.threads->map[i]); + perf_thread_map__pid(ftrace->evlist->core.threads, i)); if (append_tracing_file("set_ftrace_pid", buf) < 0) return -1; } |