libperf cpumap: Make index and nr types unsigned

The index into the cpumap array and the number of entries within the
array can never be negative, so let's make them unsigned. This is
prompted by reports that gcc 13 with -O6 is giving a
alloc-size-larger-than errors. The change makes the cpumap changes and
then updates the declaration of index variables throughout perf and
libperf to be unsigned. The two things are hard to separate as
compiler warnings about mixing signed and unsigned types breaks the
build.

Reported-by: Chingbin Li <liqb365@163.com>
Closes: https://lore.kernel.org/lkml/20260212025127.841090-1-liqb365@163.com/
Tested-by: Chingbin Li <liqb365@163.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

4 files changed, 34 insertions, 35 deletions

diff --git a/tools/lib/perf/cpumap.c b/tools/lib/perf/cpumap.c
index 4160e7d2e120..e51b0490ad57 100644
--- a/tools/lib/perf/cpumap.c
+++ b/tools/lib/perf/cpumap.c
@@ -15,12 +15,12 @@
 
 #define MAX_NR_CPUS 4096
 
-void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus)
+void perf_cpu_map__set_nr(struct perf_cpu_map *map, unsigned int nr_cpus)
 {
 	RC_CHK_ACCESS(map)->nr = nr_cpus;
 }
 
-struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus)
+struct perf_cpu_map *perf_cpu_map__alloc(unsigned int nr_cpus)
 {
 	RC_STRUCT(perf_cpu_map) *cpus;
 	struct perf_cpu_map *result;
@@ -78,7 +78,7 @@ void perf_cpu_map__put(struct perf_cpu_map *map)
 static struct perf_cpu_map *cpu_map__new_sysconf(void)
 {
 	struct perf_cpu_map *cpus;
-	int nr_cpus, nr_cpus_conf;
+	long nr_cpus, nr_cpus_conf;
 
 	nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
 	if (nr_cpus < 0)
@@ -86,15 +86,13 @@ static struct perf_cpu_map *cpu_map__new_sysconf(void)
 
 	nr_cpus_conf = sysconf(_SC_NPROCESSORS_CONF);
 	if (nr_cpus != nr_cpus_conf) {
-		pr_warning("Number of online CPUs (%d) differs from the number configured (%d) the CPU map will only cover the first %d CPUs.",
+		pr_warning("Number of online CPUs (%ld) differs from the number configured (%ld) the CPU map will only cover the first %ld CPUs.",
 			nr_cpus, nr_cpus_conf, nr_cpus);
 	}
 
 	cpus = perf_cpu_map__alloc(nr_cpus);
 	if (cpus != NULL) {
-		int i;
-
-		for (i = 0; i < nr_cpus; ++i)
+		for (long i = 0; i < nr_cpus; ++i)
 			RC_CHK_ACCESS(cpus)->map[i].cpu = i;
 	}
 
@@ -132,23 +130,23 @@ static int cmp_cpu(const void *a, const void *b)
 	return cpu_a->cpu - cpu_b->cpu;
 }
 
-static struct perf_cpu __perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx)
+static struct perf_cpu __perf_cpu_map__cpu(const struct perf_cpu_map *cpus, unsigned int idx)
 {
 	return RC_CHK_ACCESS(cpus)->map[idx];
 }
 
-static struct perf_cpu_map *cpu_map__trim_new(int nr_cpus, const struct perf_cpu *tmp_cpus)
+static struct perf_cpu_map *cpu_map__trim_new(unsigned int nr_cpus, const struct perf_cpu *tmp_cpus)
 {
 	size_t payload_size = nr_cpus * sizeof(struct perf_cpu);
 	struct perf_cpu_map *cpus = perf_cpu_map__alloc(nr_cpus);
-	int i, j;
 
 	if (cpus != NULL) {
+		unsigned int j = 0;
+
 		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++) {
+		for (unsigned int i = 0; i < nr_cpus; i++) {
 			if (i == 0 ||
 			    __perf_cpu_map__cpu(cpus, i).cpu !=
 			    __perf_cpu_map__cpu(cpus, i - 1).cpu) {
@@ -167,9 +165,8 @@ struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list)
 	struct perf_cpu_map *cpus = NULL;
 	unsigned long start_cpu, end_cpu = 0;
 	char *p = NULL;
-	int i, nr_cpus = 0;
+	unsigned int nr_cpus = 0, max_entries = 0;
 	struct perf_cpu *tmp_cpus = NULL, *tmp;
-	int max_entries = 0;
 
 	if (!cpu_list)
 		return perf_cpu_map__new_online_cpus();
@@ -208,9 +205,10 @@ struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list)
 
 		for (; start_cpu <= end_cpu; start_cpu++) {
 			/* check for duplicates */
-			for (i = 0; i < nr_cpus; i++)
+			for (unsigned int i = 0; i < nr_cpus; i++) {
 				if (tmp_cpus[i].cpu == (int16_t)start_cpu)
 					goto invalid;
+			}
 
 			if (nr_cpus == max_entries) {
 				max_entries += max(end_cpu - start_cpu + 1, 16UL);
@@ -252,12 +250,12 @@ struct perf_cpu_map *perf_cpu_map__new_int(int cpu)
 	return cpus;
 }
 
-static int __perf_cpu_map__nr(const struct perf_cpu_map *cpus)
+static unsigned int __perf_cpu_map__nr(const struct perf_cpu_map *cpus)
 {
 	return RC_CHK_ACCESS(cpus)->nr;
 }
 
-struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx)
+struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, unsigned int idx)
 {
 	struct perf_cpu result = {
 		.cpu = -1
@@ -269,7 +267,7 @@ struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx)
 	return result;
 }
 
-int perf_cpu_map__nr(const struct perf_cpu_map *cpus)
+unsigned int perf_cpu_map__nr(const struct perf_cpu_map *cpus)
 {
 	return cpus ? __perf_cpu_map__nr(cpus) : 1;
 }
@@ -294,7 +292,7 @@ bool perf_cpu_map__is_empty(const struct perf_cpu_map *map)
 
 int perf_cpu_map__idx(const struct perf_cpu_map *cpus, struct perf_cpu cpu)
 {
-	int low, high;
+	unsigned int low, high;
 
 	if (!cpus)
 		return -1;
@@ -324,7 +322,7 @@ bool perf_cpu_map__has(const struct perf_cpu_map *cpus, struct perf_cpu cpu)
 
 bool perf_cpu_map__equal(const struct perf_cpu_map *lhs, const struct perf_cpu_map *rhs)
 {
-	int nr;
+	unsigned int nr;
 
 	if (lhs == rhs)
 		return true;
@@ -336,7 +334,7 @@ bool perf_cpu_map__equal(const struct perf_cpu_map *lhs, const struct perf_cpu_m
 	if (nr != __perf_cpu_map__nr(rhs))
 		return false;
 
-	for (int idx = 0; idx < nr; idx++) {
+	for (unsigned int idx = 0; idx < nr; idx++) {
 		if (__perf_cpu_map__cpu(lhs, idx).cpu != __perf_cpu_map__cpu(rhs, idx).cpu)
 			return false;
 	}
@@ -353,7 +351,7 @@ struct perf_cpu perf_cpu_map__min(const struct perf_cpu_map *map)
 	struct perf_cpu cpu, result = {
 		.cpu = -1
 	};
-	int idx;
+	unsigned int idx;
 
 	perf_cpu_map__for_each_cpu_skip_any(cpu, idx, map) {
 		result = cpu;
@@ -384,7 +382,7 @@ bool perf_cpu_map__is_subset(const struct perf_cpu_map *a, const struct perf_cpu
 	if (!a || __perf_cpu_map__nr(b) > __perf_cpu_map__nr(a))
 		return false;
 
-	for (int i = 0, j = 0; i < __perf_cpu_map__nr(a); i++) {
+	for (unsigned int i = 0, j = 0; i < __perf_cpu_map__nr(a); i++) {
 		if (__perf_cpu_map__cpu(a, i).cpu > __perf_cpu_map__cpu(b, j).cpu)
 			return false;
 		if (__perf_cpu_map__cpu(a, i).cpu == __perf_cpu_map__cpu(b, j).cpu) {
@@ -410,8 +408,7 @@ bool perf_cpu_map__is_subset(const struct perf_cpu_map *a, const struct perf_cpu
 int perf_cpu_map__merge(struct perf_cpu_map **orig, struct perf_cpu_map *other)
 {
 	struct perf_cpu *tmp_cpus;
-	int tmp_len;
-	int i, j, k;
+	unsigned int tmp_len, i, j, k;
 	struct perf_cpu_map *merged;
 
 	if (perf_cpu_map__is_subset(*orig, other))
@@ -455,7 +452,7 @@ int perf_cpu_map__merge(struct perf_cpu_map **orig, struct perf_cpu_map *other)
 struct perf_cpu_map *perf_cpu_map__intersect(struct perf_cpu_map *orig,
 					     struct perf_cpu_map *other)
 {
-	int i, j, k;
+	unsigned int i, j, k;
 	struct perf_cpu_map *merged;
 
 	if (perf_cpu_map__is_subset(other, orig))
diff --git a/tools/lib/perf/evsel.c b/tools/lib/perf/evsel.c
index 13a307fc75ae..f747c0bc692d 100644
--- a/tools/lib/perf/evsel.c
+++ b/tools/lib/perf/evsel.c
@@ -127,7 +127,8 @@ int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus,
 		     struct perf_thread_map *threads)
 {
 	struct perf_cpu cpu;
-	int idx, thread, err = 0;
+	unsigned int idx;
+	int thread, err = 0;
 
 	if (cpus == NULL) {
 		static struct perf_cpu_map *empty_cpu_map;
@@ -460,7 +461,7 @@ int perf_evsel__enable_cpu(struct perf_evsel *evsel, int cpu_map_idx)
 int perf_evsel__enable_thread(struct perf_evsel *evsel, int thread)
 {
 	struct perf_cpu cpu __maybe_unused;
-	int idx;
+	unsigned int idx;
 	int err;
 
 	perf_cpu_map__for_each_cpu(cpu, idx, evsel->cpus) {
@@ -499,12 +500,13 @@ int perf_evsel__disable(struct perf_evsel *evsel)
 
 int perf_evsel__apply_filter(struct perf_evsel *evsel, const char *filter)
 {
-	int err = 0, i;
+	int err = 0;
 
-	for (i = 0; i < perf_cpu_map__nr(evsel->cpus) && !err; i++)
+	for (unsigned int i = 0; i < perf_cpu_map__nr(evsel->cpus) && !err; i++) {
 		err = perf_evsel__run_ioctl(evsel,
 				     PERF_EVENT_IOC_SET_FILTER,
 				     (void *)filter, i);
+	}
 	return err;
 }
 
diff --git a/tools/lib/perf/include/internal/cpumap.h b/tools/lib/perf/include/internal/cpumap.h
index e2be2d17c32b..c19678188b17 100644
--- a/tools/lib/perf/include/internal/cpumap.h
+++ b/tools/lib/perf/include/internal/cpumap.h
@@ -16,16 +16,16 @@
 DECLARE_RC_STRUCT(perf_cpu_map) {
 	refcount_t	refcnt;
 	/** Length of the map array. */
-	int		nr;
+	unsigned int	nr;
 	/** The CPU values. */
 	struct perf_cpu	map[];
 };
 
-struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus);
+struct perf_cpu_map *perf_cpu_map__alloc(unsigned 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);
 
-void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus);
+void perf_cpu_map__set_nr(struct perf_cpu_map *map, unsigned int nr_cpus);
 
 static inline refcount_t *perf_cpu_map__refcnt(struct perf_cpu_map *map)
 {
diff --git a/tools/lib/perf/include/perf/cpumap.h b/tools/lib/perf/include/perf/cpumap.h
index 58cc5c5fa47c..a1dd25db65b6 100644
--- a/tools/lib/perf/include/perf/cpumap.h
+++ b/tools/lib/perf/include/perf/cpumap.h
@@ -49,7 +49,7 @@ LIBPERF_API void perf_cpu_map__put(struct perf_cpu_map *map);
  * perf_cpu_map__cpu - get the CPU value at the given index. Returns -1 if index
  *                     is invalid.
  */
-LIBPERF_API struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx);
+LIBPERF_API struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, unsigned int idx);
 /**
  * perf_cpu_map__nr - for an empty map returns 1, as perf_cpu_map__cpu returns a
  *                    cpu of -1 for an invalid index, this makes an empty map
@@ -57,7 +57,7 @@ LIBPERF_API struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, i
  *                    the result is the number CPUs in the map plus one if the
  *                    "any CPU"/dummy value is present.
  */
-LIBPERF_API int perf_cpu_map__nr(const struct perf_cpu_map *cpus);
+LIBPERF_API unsigned int perf_cpu_map__nr(const struct perf_cpu_map *cpus);
 /**
  * perf_cpu_map__has_any_cpu_or_is_empty - is map either empty or has the "any CPU"/dummy value.
  */