Re: [PATCH v7 2/5] perf cpumap: Add reference count checking
From: Arnaldo Carvalho de Melo
Date: Tue Apr 11 2023 - 14:19:24 EST
Em Fri, Apr 07, 2023 at 04:04:02PM -0700, Ian Rogers escreveu:
> Enabled when REFCNT_CHECKING is defined. The change adds a memory
> allocated pointer that is interposed between the reference counted
> cpu map at a get and freed by a put. The pointer replaces the original
> perf_cpu_map struct, so use of the perf_cpu_map via APIs remains
> unchanged. Any use of the cpu map without the API requires two versions,
> handled via the RC_CHK_ACCESS macro.
>
> This change is intended to catch:
> - use after put: using a cpumap after you have put it will cause a
> segv.
> - unbalanced puts: two puts for a get will result in a double free
> that can be captured and reported by tools like address sanitizer,
> including with the associated stack traces of allocation and frees.
> - missing puts: if a put is missing then the get turns into a memory
> leak that can be reported by leak sanitizer, including the stack
> trace at the point the get occurs.
I think this should be further split into self contained patches as it
does:
1. The use of the RC_ macros wrapping, that should be all on the same
patch as to allow, after applying it, to test with REFCNT_CHECKING set.
2. Exports perf_cpu_map__alloc() from libperf for use in tools/perf
And its usage should be on a separate patch:
> - struct perf_cpu_map *cpus = malloc(sizeof(*cpus) + sizeof(int) * nr);
> + struct perf_cpu_map *cpus = perf_cpu_map__alloc(nr);
3. Shouldn't we have a map__refcnt(map) accessor to avoid using those
verbose macros outside the object that is having its reference counts
checked?
i.e. to avoid this:
> + TEST_ASSERT_VAL("wrong refcnt", refcount_read(&RC_CHK_ACCESS(map)->refcnt) == 1);
Even in the class main file it would help:
> static void cpu_map__delete(struct perf_cpu_map *map)
> {
> if (map) {
> - WARN_ONCE(refcount_read(&map->refcnt) != 0,
> + WARN_ONCE(refcount_read(&RC_CHK_ACCESS(map)->refcnt) != 0,
> "cpu_map refcnt unbalanced\n");
> - free(map);
> + RC_CHK_FREE(map);
> }
> }
These are missing convertions that should be in a separate patch, no?
> @@ -239,7 +236,7 @@ struct cpu_aggr_map *cpu_aggr_map__new(const struct perf_cpu_map *cpus,
> {
> int idx;
> struct perf_cpu cpu;
> - struct cpu_aggr_map *c = cpu_aggr_map__empty_new(cpus->nr);
> + struct cpu_aggr_map *c = cpu_aggr_map__empty_new(perf_cpu_map__nr(cpus));
>
> if (!c)
> return NULL;
> @@ -263,7 +260,7 @@ struct cpu_aggr_map *cpu_aggr_map__new(const struct perf_cpu_map *cpus,
> }
> }
> /* Trim. */
> - if (c->nr != cpus->nr) {
> + if (c->nr != perf_cpu_map__nr(cpus)) {
> struct cpu_aggr_map *trimmed_c =
> realloc(c,
> sizeof(struct cpu_aggr_map) + sizeof(struct aggr_cpu_id) * c->nr);
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;
And I wonder how we could make this less of an eye sore,
internationalization on userspace source code define:
#define _(msg) gettext(msg)
To avoid having all strings wrapped with the long "gettext(" prefix, I
wonder if we can't have something like:
#define _(map) RC_CHK_ACCESS(map)
So that the patches become:
- matched_cpus->nr
+ _(matched_cpus)->nr
Since wrapping accesses takes place more than checking a free, get or
put? If _ is considered too extreme even with the gettext precedent, and
being something local, i.e. just inside cpumap.c, then maybe we can have
a:
#define map_ptr(map) RC_CHK_ACCESS(map)
- matched_cpus->nr
+ map__ptr(matched_cpus)->nr
But overall trying to reduce the impact on source code readability with
all these macros is something we should think a bit more :-\
The accessors that were already merged are nice and clean and provide a
way to hook these checks in a single source file, that was good. With
map__refcnt() we reduce it a bit more, so we're making progress.
Thanks for working on this!
- Arnaldo
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> ---
> tools/lib/perf/Makefile | 2 +-
> tools/lib/perf/cpumap.c | 94 +++++++++++++-----------
> tools/lib/perf/include/internal/cpumap.h | 4 +-
> tools/perf/tests/cpumap.c | 4 +-
> tools/perf/util/cpumap.c | 40 +++++-----
> tools/perf/util/pmu.c | 8 +-
> 6 files changed, 81 insertions(+), 71 deletions(-)
>
> diff --git a/tools/lib/perf/Makefile b/tools/lib/perf/Makefile
> index d8cad124e4c5..3a9b2140aa04 100644
> --- a/tools/lib/perf/Makefile
> +++ b/tools/lib/perf/Makefile
> @@ -188,7 +188,7 @@ install_lib: libs
> cp -fpR $(LIBPERF_ALL) $(DESTDIR)$(libdir_SQ)
>
> HDRS := bpf_perf.h core.h cpumap.h threadmap.h evlist.h evsel.h event.h mmap.h
> -INTERNAL_HDRS := cpumap.h evlist.h evsel.h lib.h mmap.h threadmap.h xyarray.h
> +INTERNAL_HDRS := cpumap.h evlist.h evsel.h lib.h mmap.h rc_check.h threadmap.h xyarray.h
>
> INSTALL_HDRS_PFX := $(DESTDIR)$(prefix)/include/perf
> INSTALL_HDRS := $(addprefix $(INSTALL_HDRS_PFX)/, $(HDRS))
> diff --git a/tools/lib/perf/cpumap.c b/tools/lib/perf/cpumap.c
> index 6cd0be7c1bb4..56eed1ac80d9 100644
> --- a/tools/lib/perf/cpumap.c
> +++ b/tools/lib/perf/cpumap.c
> @@ -10,16 +10,16 @@
> #include <ctype.h>
> #include <limits.h>
>
> -static struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus)
> +struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus)
> {
> - struct perf_cpu_map *cpus = malloc(sizeof(*cpus) + sizeof(struct perf_cpu) * nr_cpus);
> -
> - if (cpus != NULL) {
> + struct perf_cpu_map *result;
> + RC_STRUCT(perf_cpu_map) *cpus =
> + malloc(sizeof(*cpus) + sizeof(struct perf_cpu) * nr_cpus);
> + if (ADD_RC_CHK(result, cpus)) {
> cpus->nr = nr_cpus;
> refcount_set(&cpus->refcnt, 1);
> -
> }
> - return cpus;
> + return result;
> }
>
> struct perf_cpu_map *perf_cpu_map__dummy_new(void)
> @@ -27,7 +27,7 @@ struct perf_cpu_map *perf_cpu_map__dummy_new(void)
> struct perf_cpu_map *cpus = perf_cpu_map__alloc(1);
>
> if (cpus)
> - cpus->map[0].cpu = -1;
> + RC_CHK_ACCESS(cpus)->map[0].cpu = -1;
>
> return cpus;
> }
> @@ -35,23 +35,30 @@ struct perf_cpu_map *perf_cpu_map__dummy_new(void)
> static void cpu_map__delete(struct perf_cpu_map *map)
> {
> if (map) {
> - WARN_ONCE(refcount_read(&map->refcnt) != 0,
> + WARN_ONCE(refcount_read(&RC_CHK_ACCESS(map)->refcnt) != 0,
> "cpu_map refcnt unbalanced\n");
> - free(map);
> + RC_CHK_FREE(map);
> }
> }
>
> struct perf_cpu_map *perf_cpu_map__get(struct perf_cpu_map *map)
> {
> - if (map)
> - refcount_inc(&map->refcnt);
> - return map;
> + struct perf_cpu_map *result;
> +
> + if (RC_CHK_GET(result, map))
> + refcount_inc(&RC_CHK_ACCESS(map)->refcnt);
> +
> + return result;
> }
>
> void perf_cpu_map__put(struct perf_cpu_map *map)
> {
> - if (map && refcount_dec_and_test(&map->refcnt))
> - cpu_map__delete(map);
> + if (map) {
> + if (refcount_dec_and_test(&RC_CHK_ACCESS(map)->refcnt))
> + cpu_map__delete(map);
> + else
> + RC_CHK_PUT(map);
> + }
> }
>
> static struct perf_cpu_map *cpu_map__default_new(void)
> @@ -68,7 +75,7 @@ static struct perf_cpu_map *cpu_map__default_new(void)
> int i;
>
> for (i = 0; i < nr_cpus; ++i)
> - cpus->map[i].cpu = i;
> + RC_CHK_ACCESS(cpus)->map[i].cpu = i;
> }
>
> return cpus;
> @@ -94,15 +101,16 @@ static struct perf_cpu_map *cpu_map__trim_new(int nr_cpus, const struct perf_cpu
> int i, j;
>
> if (cpus != NULL) {
> - memcpy(cpus->map, tmp_cpus, payload_size);
> - qsort(cpus->map, nr_cpus, sizeof(struct perf_cpu), cmp_cpu);
> + memcpy(RC_CHK_ACCESS(cpus)->map, tmp_cpus, payload_size);
> + qsort(RC_CHK_ACCESS(cpus)->map, nr_cpus, sizeof(struct perf_cpu), cmp_cpu);
> /* Remove dups */
> j = 0;
> for (i = 0; i < nr_cpus; i++) {
> - if (i == 0 || cpus->map[i].cpu != cpus->map[i - 1].cpu)
> - cpus->map[j++].cpu = cpus->map[i].cpu;
> + if (i == 0 ||
> + RC_CHK_ACCESS(cpus)->map[i].cpu != RC_CHK_ACCESS(cpus)->map[i - 1].cpu)
> + RC_CHK_ACCESS(cpus)->map[j++].cpu = RC_CHK_ACCESS(cpus)->map[i].cpu;
> }
> - cpus->nr = j;
> + RC_CHK_ACCESS(cpus)->nr = j;
> assert(j <= nr_cpus);
> }
> return cpus;
> @@ -263,20 +271,20 @@ struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx)
> .cpu = -1
> };
>
> - if (cpus && idx < cpus->nr)
> - return cpus->map[idx];
> + if (cpus && idx < RC_CHK_ACCESS(cpus)->nr)
> + return RC_CHK_ACCESS(cpus)->map[idx];
>
> return result;
> }
>
> int perf_cpu_map__nr(const struct perf_cpu_map *cpus)
> {
> - return cpus ? cpus->nr : 1;
> + return cpus ? RC_CHK_ACCESS(cpus)->nr : 1;
> }
>
> bool perf_cpu_map__empty(const struct perf_cpu_map *map)
> {
> - return map ? map->map[0].cpu == -1 : true;
> + return map ? RC_CHK_ACCESS(map)->map[0].cpu == -1 : true;
> }
>
> int perf_cpu_map__idx(const struct perf_cpu_map *cpus, struct perf_cpu cpu)
> @@ -287,10 +295,10 @@ int perf_cpu_map__idx(const struct perf_cpu_map *cpus, struct perf_cpu cpu)
> return -1;
>
> low = 0;
> - high = cpus->nr;
> + high = RC_CHK_ACCESS(cpus)->nr;
> while (low < high) {
> int idx = (low + high) / 2;
> - struct perf_cpu cpu_at_idx = cpus->map[idx];
> + struct perf_cpu cpu_at_idx = RC_CHK_ACCESS(cpus)->map[idx];
>
> if (cpu_at_idx.cpu == cpu.cpu)
> return idx;
> @@ -316,7 +324,9 @@ struct perf_cpu perf_cpu_map__max(const struct perf_cpu_map *map)
> };
>
> // cpu_map__trim_new() qsort()s it, cpu_map__default_new() sorts it as well.
> - return map->nr > 0 ? map->map[map->nr - 1] : result;
> + return RC_CHK_ACCESS(map)->nr > 0
> + ? RC_CHK_ACCESS(map)->map[RC_CHK_ACCESS(map)->nr - 1]
> + : result;
> }
>
> /** Is 'b' a subset of 'a'. */
> @@ -324,15 +334,15 @@ bool perf_cpu_map__is_subset(const struct perf_cpu_map *a, const struct perf_cpu
> {
> if (a == b || !b)
> return true;
> - if (!a || b->nr > a->nr)
> + if (!a || RC_CHK_ACCESS(b)->nr > RC_CHK_ACCESS(a)->nr)
> return false;
>
> - for (int i = 0, j = 0; i < a->nr; i++) {
> - if (a->map[i].cpu > b->map[j].cpu)
> + for (int i = 0, j = 0; i < RC_CHK_ACCESS(a)->nr; i++) {
> + if (RC_CHK_ACCESS(a)->map[i].cpu > RC_CHK_ACCESS(b)->map[j].cpu)
> return false;
> - if (a->map[i].cpu == b->map[j].cpu) {
> + if (RC_CHK_ACCESS(a)->map[i].cpu == RC_CHK_ACCESS(b)->map[j].cpu) {
> j++;
> - if (j == b->nr)
> + if (j == RC_CHK_ACCESS(b)->nr)
> return true;
> }
> }
> @@ -362,27 +372,27 @@ struct perf_cpu_map *perf_cpu_map__merge(struct perf_cpu_map *orig,
> return perf_cpu_map__get(other);
> }
>
> - tmp_len = orig->nr + other->nr;
> + tmp_len = RC_CHK_ACCESS(orig)->nr + RC_CHK_ACCESS(other)->nr;
> tmp_cpus = malloc(tmp_len * sizeof(struct perf_cpu));
> if (!tmp_cpus)
> return NULL;
>
> /* Standard merge algorithm from wikipedia */
> i = j = k = 0;
> - while (i < orig->nr && j < other->nr) {
> - if (orig->map[i].cpu <= other->map[j].cpu) {
> - if (orig->map[i].cpu == other->map[j].cpu)
> + while (i < RC_CHK_ACCESS(orig)->nr && j < RC_CHK_ACCESS(other)->nr) {
> + if (RC_CHK_ACCESS(orig)->map[i].cpu <= RC_CHK_ACCESS(other)->map[j].cpu) {
> + if (RC_CHK_ACCESS(orig)->map[i].cpu == RC_CHK_ACCESS(other)->map[j].cpu)
> j++;
> - tmp_cpus[k++] = orig->map[i++];
> + tmp_cpus[k++] = RC_CHK_ACCESS(orig)->map[i++];
> } else
> - tmp_cpus[k++] = other->map[j++];
> + tmp_cpus[k++] = RC_CHK_ACCESS(other)->map[j++];
> }
>
> - while (i < orig->nr)
> - tmp_cpus[k++] = orig->map[i++];
> + while (i < RC_CHK_ACCESS(orig)->nr)
> + tmp_cpus[k++] = RC_CHK_ACCESS(orig)->map[i++];
>
> - while (j < other->nr)
> - tmp_cpus[k++] = other->map[j++];
> + while (j < RC_CHK_ACCESS(other)->nr)
> + tmp_cpus[k++] = RC_CHK_ACCESS(other)->map[j++];
> assert(k <= tmp_len);
>
> merged = cpu_map__trim_new(k, tmp_cpus);
> diff --git a/tools/lib/perf/include/internal/cpumap.h b/tools/lib/perf/include/internal/cpumap.h
> index 35dd29642296..6c01bee4d048 100644
> --- a/tools/lib/perf/include/internal/cpumap.h
> +++ b/tools/lib/perf/include/internal/cpumap.h
> @@ -4,6 +4,7 @@
>
> #include <linux/refcount.h>
> #include <perf/cpumap.h>
> +#include <internal/rc_check.h>
>
> /**
> * A sized, reference counted, sorted array of integers representing CPU
> @@ -12,7 +13,7 @@
> * gaps if CPU numbers were used. For events associated with a pid, rather than
> * a CPU, a single dummy map with an entry of -1 is used.
> */
> -struct perf_cpu_map {
> +DECLARE_RC_STRUCT(perf_cpu_map) {
> refcount_t refcnt;
> /** Length of the map array. */
> int nr;
> @@ -24,6 +25,7 @@ struct perf_cpu_map {
> #define MAX_NR_CPUS 2048
> #endif
>
> +struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus);
> int perf_cpu_map__idx(const struct perf_cpu_map *cpus, struct perf_cpu cpu);
> bool perf_cpu_map__is_subset(const struct perf_cpu_map *a, const struct perf_cpu_map *b);
>
> diff --git a/tools/perf/tests/cpumap.c b/tools/perf/tests/cpumap.c
> index 3150fc1fed6f..d6f77b676d11 100644
> --- a/tools/perf/tests/cpumap.c
> +++ b/tools/perf/tests/cpumap.c
> @@ -68,7 +68,7 @@ static int process_event_cpus(struct perf_tool *tool __maybe_unused,
> TEST_ASSERT_VAL("wrong nr", perf_cpu_map__nr(map) == 2);
> TEST_ASSERT_VAL("wrong cpu", perf_cpu_map__cpu(map, 0).cpu == 1);
> TEST_ASSERT_VAL("wrong cpu", perf_cpu_map__cpu(map, 1).cpu == 256);
> - TEST_ASSERT_VAL("wrong refcnt", refcount_read(&map->refcnt) == 1);
> + TEST_ASSERT_VAL("wrong refcnt", refcount_read(&RC_CHK_ACCESS(map)->refcnt) == 1);
> perf_cpu_map__put(map);
> return 0;
> }
> @@ -94,7 +94,7 @@ static int process_event_range_cpus(struct perf_tool *tool __maybe_unused,
> TEST_ASSERT_VAL("wrong nr", perf_cpu_map__nr(map) == 256);
> TEST_ASSERT_VAL("wrong cpu", perf_cpu_map__cpu(map, 0).cpu == 1);
> TEST_ASSERT_VAL("wrong cpu", perf_cpu_map__max(map).cpu == 256);
> - TEST_ASSERT_VAL("wrong refcnt", refcount_read(&map->refcnt) == 1);
> + TEST_ASSERT_VAL("wrong refcnt", refcount_read(&RC_CHK_ACCESS(map)->refcnt) == 1);
> perf_cpu_map__put(map);
> return 0;
> }
> diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
> index 5e564974fba4..22453893105f 100644
> --- a/tools/perf/util/cpumap.c
> +++ b/tools/perf/util/cpumap.c
> @@ -77,9 +77,9 @@ static struct perf_cpu_map *cpu_map__from_entries(const struct perf_record_cpu_m
> * otherwise it would become 65535.
> */
> if (data->cpus_data.cpu[i] == (u16) -1)
> - map->map[i].cpu = -1;
> + RC_CHK_ACCESS(map)->map[i].cpu = -1;
> else
> - map->map[i].cpu = (int) data->cpus_data.cpu[i];
> + RC_CHK_ACCESS(map)->map[i].cpu = (int) data->cpus_data.cpu[i];
> }
> }
>
> @@ -107,7 +107,7 @@ static struct perf_cpu_map *cpu_map__from_mask(const struct perf_record_cpu_map_
>
> perf_record_cpu_map_data__read_one_mask(data, i, local_copy);
> for_each_set_bit(cpu, local_copy, 64)
> - map->map[j++].cpu = cpu + cpus_per_i;
> + RC_CHK_ACCESS(map)->map[j++].cpu = cpu + cpus_per_i;
> }
> return map;
>
> @@ -124,11 +124,11 @@ static struct perf_cpu_map *cpu_map__from_range(const struct perf_record_cpu_map
> return NULL;
>
> if (data->range_cpu_data.any_cpu)
> - map->map[i++].cpu = -1;
> + RC_CHK_ACCESS(map)->map[i++].cpu = -1;
>
> for (int cpu = data->range_cpu_data.start_cpu; cpu <= data->range_cpu_data.end_cpu;
> i++, cpu++)
> - map->map[i].cpu = cpu;
> + RC_CHK_ACCESS(map)->map[i].cpu = cpu;
>
> return map;
> }
> @@ -160,16 +160,13 @@ size_t cpu_map__fprintf(struct perf_cpu_map *map, FILE *fp)
>
> struct perf_cpu_map *perf_cpu_map__empty_new(int nr)
> {
> - struct perf_cpu_map *cpus = malloc(sizeof(*cpus) + sizeof(int) * nr);
> + struct perf_cpu_map *cpus = perf_cpu_map__alloc(nr);
>
> if (cpus != NULL) {
> int i;
>
> - cpus->nr = nr;
> for (i = 0; i < nr; i++)
> - cpus->map[i].cpu = -1;
> -
> - refcount_set(&cpus->refcnt, 1);
> + RC_CHK_ACCESS(cpus)->map[i].cpu = -1;
> }
>
> return cpus;
> @@ -239,7 +236,7 @@ struct cpu_aggr_map *cpu_aggr_map__new(const struct perf_cpu_map *cpus,
> {
> int idx;
> struct perf_cpu cpu;
> - struct cpu_aggr_map *c = cpu_aggr_map__empty_new(cpus->nr);
> + struct cpu_aggr_map *c = cpu_aggr_map__empty_new(perf_cpu_map__nr(cpus));
>
> if (!c)
> return NULL;
> @@ -263,7 +260,7 @@ struct cpu_aggr_map *cpu_aggr_map__new(const struct perf_cpu_map *cpus,
> }
> }
> /* Trim. */
> - if (c->nr != cpus->nr) {
> + if (c->nr != perf_cpu_map__nr(cpus)) {
> struct cpu_aggr_map *trimmed_c =
> realloc(c,
> sizeof(struct cpu_aggr_map) + sizeof(struct aggr_cpu_id) * c->nr);
> @@ -582,31 +579,32 @@ size_t cpu_map__snprint(struct perf_cpu_map *map, char *buf, size_t size)
>
> #define COMMA first ? "" : ","
>
> - for (i = 0; i < map->nr + 1; i++) {
> + for (i = 0; i < perf_cpu_map__nr(map) + 1; i++) {
> struct perf_cpu cpu = { .cpu = INT_MAX };
> - bool last = i == map->nr;
> + bool last = i == perf_cpu_map__nr(map);
>
> if (!last)
> - cpu = map->map[i];
> + cpu = perf_cpu_map__cpu(map, i);
>
> if (start == -1) {
> start = i;
> if (last) {
> ret += snprintf(buf + ret, size - ret,
> "%s%d", COMMA,
> - map->map[i].cpu);
> + perf_cpu_map__cpu(map, i).cpu);
> }
> - } else if (((i - start) != (cpu.cpu - map->map[start].cpu)) || last) {
> + } else if (((i - start) != (cpu.cpu - perf_cpu_map__cpu(map, start).cpu)) || last) {
> int end = i - 1;
>
> if (start == end) {
> ret += snprintf(buf + ret, size - ret,
> "%s%d", COMMA,
> - map->map[start].cpu);
> + perf_cpu_map__cpu(map, start).cpu);
> } else {
> ret += snprintf(buf + ret, size - ret,
> "%s%d-%d", COMMA,
> - map->map[start].cpu, map->map[end].cpu);
> + perf_cpu_map__cpu(map, start).cpu,
> + perf_cpu_map__cpu(map, end).cpu);
> }
> first = false;
> start = i;
> @@ -633,7 +631,7 @@ size_t cpu_map__snprint_mask(struct perf_cpu_map *map, char *buf, size_t size)
> int i, cpu;
> char *ptr = buf;
> unsigned char *bitmap;
> - struct perf_cpu last_cpu = perf_cpu_map__cpu(map, map->nr - 1);
> + struct perf_cpu last_cpu = perf_cpu_map__cpu(map, perf_cpu_map__nr(map) - 1);
>
> if (buf == NULL)
> return 0;
> @@ -644,7 +642,7 @@ size_t cpu_map__snprint_mask(struct perf_cpu_map *map, char *buf, size_t size)
> return 0;
> }
>
> - for (i = 0; i < map->nr; i++) {
> + for (i = 0; i < perf_cpu_map__nr(map); i++) {
> cpu = perf_cpu_map__cpu(map, i).cpu;
> bitmap[cpu / 8] |= 1 << (cpu % 8);
> }
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index 91cccfb3c515..a9109605425c 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -2016,13 +2016,13 @@ int perf_pmu__cpus_match(struct perf_pmu *pmu, struct perf_cpu_map *cpus,
>
> perf_cpu_map__for_each_cpu(cpu, i, cpus) {
> if (!perf_cpu_map__has(pmu_cpus, cpu))
> - unmatched_cpus->map[unmatched_nr++] = cpu;
> + RC_CHK_ACCESS(unmatched_cpus)->map[unmatched_nr++] = cpu;
> else
> - matched_cpus->map[matched_nr++] = cpu;
> + RC_CHK_ACCESS(matched_cpus)->map[matched_nr++] = cpu;
> }
>
> - unmatched_cpus->nr = unmatched_nr;
> - matched_cpus->nr = matched_nr;
> + RC_CHK_ACCESS(unmatched_cpus)->nr = unmatched_nr;
> + RC_CHK_ACCESS(matched_cpus)->nr = matched_nr;
> *mcpus_ptr = matched_cpus;
> *ucpus_ptr = unmatched_cpus;
> return 0;
> --
> 2.40.0.577.gac1e443424-goog
>
--
- Arnaldo