perf cpumap: Use perf_cpu_map__nr(cpus) to access cpus->nr

So that we can have a single point where to refcount check 'struct perf_cpu_map'
instances for use after free, etc.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Cc: Dmitriy Vyukov <dvyukov@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/lkml/20230407230405.2931830-3-irogers@google.com
[ Split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index 5e56497..c8484b7 100644 (file)
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -239,7 +239,7 @@ 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 +263,7 @@ 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);
@@ -582,9 +582,9 @@ 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];
@@ -633,7 +633,7 @@ 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 +644,7 @@ 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);
        }