4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jiri Olsa <[email protected]>

[ Upstream commit 4ab8455f8bd83298bf7f67ab9357e3b1cc765c7d ]

John reported crash when recording on an event under PMU with cpumask defined:

  root@localhost:~# ./perf_debug_ record -e armv8_pmuv3_0/br_mis_pred/ sleep 1
  perf: Segmentation fault
  Obtained 9 stack frames.
  ./perf_debug_() [0x4c5ef8]
  [0xffff82ba267c]
  ./perf_debug_() [0x4bc5a8]
  ./perf_debug_() [0x419550]
  ./perf_debug_() [0x41a928]
  ./perf_debug_() [0x472f58]
  ./perf_debug_() [0x473210]
  ./perf_debug_() [0x4070f4]
  /lib/aarch64-linux-gnu/libc.so.6(__libc_start_main+0xe0) [0xffff8294c8a0]
  Segmentation fault (core dumped)

We synthesize an update event that needs to touch the evsel id array, which is
not defined at that time. Fixing this by forcing the id allocation for events
with their own cpus.

Reported-by: John Garry <[email protected]>
Signed-off-by: Jiri Olsa <[email protected]>
Tested-by: John Garry <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Fixes: bfd8f72c2778 ("perf record: Synthesize unit/scale/... in event update")
Link: http://lkml.kernel.org/r/20181003212052.GA32371@krava
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 tools/perf/builtin-report.c |    1 +
 tools/perf/util/evsel.c     |    3 +++
 2 files changed, 4 insertions(+)

--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -981,6 +981,7 @@ int cmd_report(int argc, const char **ar
                        .id_index        = perf_event__process_id_index,
                        .auxtrace_info   = perf_event__process_auxtrace_info,
                        .auxtrace        = perf_event__process_auxtrace,
+                       .event_update    = perf_event__process_event_update,
                        .feature         = process_feature_event,
                        .ordered_events  = true,
                        .ordering_requires_timestamps = true,
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1078,6 +1078,9 @@ void perf_evsel__config(struct perf_evse
                attr->exclude_user   = 1;
        }
 
+       if (evsel->own_cpus)
+               evsel->attr.read_format |= PERF_FORMAT_ID;
+
        /*
         * Apply event specific term settings,
         * it overloads any global configuration.


Reply via email to