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authorThomas Richter <tmricht@linux.ibm.com>2021-04-21 14:04:00 +0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2021-04-23 15:58:10 -0300
commit671b60cb6a897a5b3832fe57657152f2c3995e25 (patch)
tree28610ba75f44500ac3414fc709df491d5d76fc9a
parentb14585d9f18dc617e975815570fe836be656b1da (diff)
downloadlinux-671b60cb6a897a5b3832fe57657152f2c3995e25.tar.bz2
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.c2
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;
}