[PATCH v2 1/3] perf record: Fix per-thread option.

From: Ian Rogers <irogers@google.com>
To: Alexey Bayduraev <alexey.bayduraev@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
	Ian Rogers <irogers@google.com>,
	Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>,
	Andi Kleen <ak@linux.intel.com>,
	Riccardo Mancini <rickyman7@gmail.com>,
	linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org
Cc: Stephane Eranian <eranian@google.com>
Subject: [PATCH v2 1/3] perf record: Fix per-thread option.
Date: Wed, 13 Apr 2022 18:46:40 -0700	[thread overview]
Message-ID: <20220414014642.3308206-1-irogers@google.com> (raw)

From: Alexey Bayduraev <alexey.bayduraev@gmail.com>

Per-thread mode doesn't have specific CPUs for events, add checks for
this case.

Minor fix to a pr_debug by Ian Rogers <irogers@google.com> to avoid an
out of bound array access.

Reported-by: Ian Rogers <irogers@google.com>
Fixes: 7954f71689f9 ("perf record: Introduce thread affinity and mmap masks")
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Alexey Bayduraev <alexey.bayduraev@gmail.com>
---
 tools/perf/builtin-record.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index ba74fab02e62..069825c48d40 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -989,8 +989,11 @@ static int record__thread_data_init_maps(struct record_thread *thread_data, stru
 	struct mmap *overwrite_mmap = evlist->overwrite_mmap;
 	struct perf_cpu_map *cpus = evlist->core.user_requested_cpus;
 
-	thread_data->nr_mmaps = bitmap_weight(thread_data->mask->maps.bits,
-					      thread_data->mask->maps.nbits);
+	if (cpu_map__is_dummy(cpus))
+		thread_data->nr_mmaps = nr_mmaps;
+	else
+		thread_data->nr_mmaps = bitmap_weight(thread_data->mask->maps.bits,
+						      thread_data->mask->maps.nbits);
 	if (mmap) {
 		thread_data->maps = zalloc(thread_data->nr_mmaps * sizeof(struct mmap *));
 		if (!thread_data->maps)
@@ -1007,16 +1010,17 @@ static int record__thread_data_init_maps(struct record_thread *thread_data, stru
 		 thread_data->nr_mmaps, thread_data->maps, thread_data->overwrite_maps);
 
 	for (m = 0, tm = 0; m < nr_mmaps && tm < thread_data->nr_mmaps; m++) {
-		if (test_bit(cpus->map[m].cpu, thread_data->mask->maps.bits)) {
+		if (cpu_map__is_dummy(cpus) ||
+		    test_bit(cpus->map[m].cpu, thread_data->mask->maps.bits)) {
 			if (thread_data->maps) {
 				thread_data->maps[tm] = &mmap[m];
 				pr_debug2("thread_data[%p]: cpu%d: maps[%d] -> mmap[%d]\n",
-					  thread_data, cpus->map[m].cpu, tm, m);
+					  thread_data, perf_cpu_map__cpu(cpus, m).cpu, tm, m);
 			}
 			if (thread_data->overwrite_maps) {
 				thread_data->overwrite_maps[tm] = &overwrite_mmap[m];
 				pr_debug2("thread_data[%p]: cpu%d: ow_maps[%d] -> ow_mmap[%d]\n",
-					  thread_data, cpus->map[m].cpu, tm, m);
+					  thread_data, perf_cpu_map__cpu(cpus, m).cpu, tm, m);
 			}
 			tm++;
 		}
@@ -3329,6 +3333,9 @@ static void record__mmap_cpu_mask_init(struct mmap_cpu_mask *mask, struct perf_c
 {
 	int c;
 
+	if (cpu_map__is_dummy(cpus))
+		return;
+
 	for (c = 0; c < cpus->nr; c++)
 		set_bit(cpus->map[c].cpu, mask->bits);
 }
@@ -3680,6 +3687,11 @@ static int record__init_thread_masks(struct record *rec)
 	if (!record__threads_enabled(rec))
 		return record__init_thread_default_masks(rec, cpus);
 
+	if (cpu_map__is_dummy(cpus)) {
+		pr_err("--per-thread option is mutually exclusive to parallel streaming mode.\n");
+		return -EINVAL;
+	}
+
 	switch (rec->opts.threads_spec) {
 	case THREAD_SPEC__CPU:
 		ret = record__init_thread_cpu_masks(rec, cpus);
-- 
2.36.0.rc0.470.gd361397f0d-goog

