Re: [PATCH v7 2/5] perf cpumap: Add reference count checking

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Tue, Apr 11, 2023 at 03:19:06PM -0300, Arnaldo Carvalho de Melo escreveu:
> I think this should be further split into self contained patches as it
> does:
 
> These should be in a separate patchset using a new perf_cpu_map__set_nr() macro:
> 
> > +     RC_CHK_ACCESS(unmatched_cpus)->nr = unmatched_nr;
> > +     RC_CHK_ACCESS(matched_cpus)->nr = matched_nr;

One more:


From bd346e2074d07031d28b34a56a43fe848f7445ca Mon Sep 17 00:00:00 2001
From: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Wed, 12 Apr 2023 14:56:28 -0300
Subject: [PATCH 1/1] perf pmu: Use perf_cpu_map__set_nr() in
 perf_pmu__cpus_match() to allow for refcnt checking

One more step to allow for checking reference counting, user after free,
etc.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Link: https://lore.kernel.org/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/pmu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 561e2616861f8bd9..760c848c9fa27728 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -2020,8 +2020,8 @@ int perf_pmu__cpus_match(struct perf_pmu *pmu, struct perf_cpu_map *cpus,
 			matched_cpus->map[matched_nr++] = cpu;
 	}
 
-	unmatched_cpus->nr = unmatched_nr;
-	matched_cpus->nr = matched_nr;
+	perf_cpu_map__set_nr(unmatched_cpus, unmatched_nr);
+	perf_cpu_map__set_nr(matched_cpus, matched_nr);
 	*mcpus_ptr = matched_cpus;
 	*ucpus_ptr = unmatched_cpus;
 	return 0;
-- 
2.39.2