Commit ca76d7d2 authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf record: Fix cpu mask bit setting for mixed mmaps 



With mixed per-thread and (system-wide) per-cpu maps, the "any cpu" value
 -1 must be skipped when setting CPU mask bits.

Prior to commit cbd7bfc7 ("tools/perf: Fix out of bound access
to cpu mask array") the invalid setting went unnoticed, but since then
it causes perf record to fail with an error.

Example:

 Before:

   $ perf record -e intel_pt// --per-thread uname
   Failed to initialize parallel data streaming masks

 After:

   $ perf record -e intel_pt// --per-thread uname
   Linux
   [ perf record: Woken up 1 times to write data ]
   [ perf record: Captured and wrote 0.068 MB perf.data ]

Fixes: ae4f8ae1 ("libperf evlist: Allow mixing per-thread and per-cpu mmaps")
Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220915122612.81738-2-adrian.hunter@intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent e1dda48e

tools/perf/builtin-record.c

+2 −0
Original line number Diff line number Diff line
@@ -3371,6 +3371,8 @@ static int record__mmap_cpu_mask_init(struct mmap_cpu_mask *mask, struct perf_cp 
		return 0;



	perf_cpu_map__for_each_cpu(cpu, idx, cpus) {

		if (cpu.cpu == -1)

			continue;

		/* Return ENODEV is input cpu is greater than max cpu */

		if ((unsigned long)cpu.cpu > mask->nbits)

			return -ENODEV;