linux/tools/lib/perf/cpumap.c
Ian Rogers dcd45b376d libperf cpumap: Ensure empty cpumap is NULL from alloc
Potential corner cases could cause a cpumap to be allocated with size
0, but an empty cpumap should be represented as NULL. Add a path in
perf_cpu_map__alloc() to ensure this.

Suggested-by: James Clark <james.clark@arm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andrew Jones <ajones@ventanamicro.com>
Cc: André Almeida <andrealmeid@igalia.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Atish Patra <atishp@rivosinc.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paran Lee <p4ranlee@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Steinar H. Gunderson <sesse@google.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Closes: https://lore.kernel.org/lkml/2cd09e7c-eb88-6726-6169-647dcd0a8101@arm.com/
Link: https://lore.kernel.org/r/20240202234057.2085863-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-03-21 10:41:28 -03:00

524 lines
12 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
#include <perf/cpumap.h>
#include <stdlib.h>
#include <linux/refcount.h>
#include <internal/cpumap.h>
#include <asm/bug.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>
#include <limits.h>
#include "internal.h"
void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus)
{
RC_CHK_ACCESS(map)->nr = nr_cpus;
}
struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus)
{
RC_STRUCT(perf_cpu_map) *cpus;
struct perf_cpu_map *result;
if (nr_cpus == 0)
return NULL;
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 result;
}
struct perf_cpu_map *perf_cpu_map__new_any_cpu(void)
{
struct perf_cpu_map *cpus = perf_cpu_map__alloc(1);
if (cpus)
RC_CHK_ACCESS(cpus)->map[0].cpu = -1;
return cpus;
}
static void cpu_map__delete(struct perf_cpu_map *map)
{
if (map) {
WARN_ONCE(refcount_read(perf_cpu_map__refcnt(map)) != 0,
"cpu_map refcnt unbalanced\n");
RC_CHK_FREE(map);
}
}
struct perf_cpu_map *perf_cpu_map__get(struct perf_cpu_map *map)
{
struct perf_cpu_map *result;
if (RC_CHK_GET(result, map))
refcount_inc(perf_cpu_map__refcnt(map));
return result;
}
void perf_cpu_map__put(struct perf_cpu_map *map)
{
if (map) {
if (refcount_dec_and_test(perf_cpu_map__refcnt(map)))
cpu_map__delete(map);
else
RC_CHK_PUT(map);
}
}
static struct perf_cpu_map *cpu_map__new_sysconf(void)
{
struct perf_cpu_map *cpus;
int nr_cpus, nr_cpus_conf;
nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
if (nr_cpus < 0)
return NULL;
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.",
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)
RC_CHK_ACCESS(cpus)->map[i].cpu = i;
}
return cpus;
}
static struct perf_cpu_map *cpu_map__new_sysfs_online(void)
{
struct perf_cpu_map *cpus = NULL;
FILE *onlnf;
onlnf = fopen("/sys/devices/system/cpu/online", "r");
if (onlnf) {
cpus = perf_cpu_map__read(onlnf);
fclose(onlnf);
}
return cpus;
}
struct perf_cpu_map *perf_cpu_map__new_online_cpus(void)
{
struct perf_cpu_map *cpus = cpu_map__new_sysfs_online();
if (cpus)
return cpus;
return cpu_map__new_sysconf();
}
static int cmp_cpu(const void *a, const void *b)
{
const struct perf_cpu *cpu_a = a, *cpu_b = b;
return cpu_a->cpu - cpu_b->cpu;
}
static struct perf_cpu __perf_cpu_map__cpu(const struct perf_cpu_map *cpus, 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)
{
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) {
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 ||
__perf_cpu_map__cpu(cpus, i).cpu !=
__perf_cpu_map__cpu(cpus, i - 1).cpu) {
RC_CHK_ACCESS(cpus)->map[j++].cpu =
__perf_cpu_map__cpu(cpus, i).cpu;
}
}
perf_cpu_map__set_nr(cpus, j);
assert(j <= nr_cpus);
}
return cpus;
}
struct perf_cpu_map *perf_cpu_map__read(FILE *file)
{
struct perf_cpu_map *cpus = NULL;
int nr_cpus = 0;
struct perf_cpu *tmp_cpus = NULL, *tmp;
int max_entries = 0;
int n, cpu, prev;
char sep;
sep = 0;
prev = -1;
for (;;) {
n = fscanf(file, "%u%c", &cpu, &sep);
if (n <= 0)
break;
if (prev >= 0) {
int new_max = nr_cpus + cpu - prev - 1;
WARN_ONCE(new_max >= MAX_NR_CPUS, "Perf can support %d CPUs. "
"Consider raising MAX_NR_CPUS\n", MAX_NR_CPUS);
if (new_max >= max_entries) {
max_entries = new_max + MAX_NR_CPUS / 2;
tmp = realloc(tmp_cpus, max_entries * sizeof(struct perf_cpu));
if (tmp == NULL)
goto out_free_tmp;
tmp_cpus = tmp;
}
while (++prev < cpu)
tmp_cpus[nr_cpus++].cpu = prev;
}
if (nr_cpus == max_entries) {
max_entries += MAX_NR_CPUS;
tmp = realloc(tmp_cpus, max_entries * sizeof(struct perf_cpu));
if (tmp == NULL)
goto out_free_tmp;
tmp_cpus = tmp;
}
tmp_cpus[nr_cpus++].cpu = cpu;
if (n == 2 && sep == '-')
prev = cpu;
else
prev = -1;
if (n == 1 || sep == '\n')
break;
}
if (nr_cpus > 0)
cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
out_free_tmp:
free(tmp_cpus);
return cpus;
}
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;
struct perf_cpu *tmp_cpus = NULL, *tmp;
int max_entries = 0;
if (!cpu_list)
return perf_cpu_map__new_online_cpus();
/*
* must handle the case of empty cpumap to cover
* TOPOLOGY header for NUMA nodes with no CPU
* ( e.g., because of CPU hotplug)
*/
if (!isdigit(*cpu_list) && *cpu_list != '\0')
goto out;
while (isdigit(*cpu_list)) {
p = NULL;
start_cpu = strtoul(cpu_list, &p, 0);
if (start_cpu >= INT_MAX
|| (*p != '\0' && *p != ',' && *p != '-'))
goto invalid;
if (*p == '-') {
cpu_list = ++p;
p = NULL;
end_cpu = strtoul(cpu_list, &p, 0);
if (end_cpu >= INT_MAX || (*p != '\0' && *p != ','))
goto invalid;
if (end_cpu < start_cpu)
goto invalid;
} else {
end_cpu = start_cpu;
}
WARN_ONCE(end_cpu >= MAX_NR_CPUS, "Perf can support %d CPUs. "
"Consider raising MAX_NR_CPUS\n", MAX_NR_CPUS);
for (; start_cpu <= end_cpu; start_cpu++) {
/* check for duplicates */
for (i = 0; i < nr_cpus; i++)
if (tmp_cpus[i].cpu == (int)start_cpu)
goto invalid;
if (nr_cpus == max_entries) {
max_entries += MAX_NR_CPUS;
tmp = realloc(tmp_cpus, max_entries * sizeof(struct perf_cpu));
if (tmp == NULL)
goto invalid;
tmp_cpus = tmp;
}
tmp_cpus[nr_cpus++].cpu = (int)start_cpu;
}
if (*p)
++p;
cpu_list = p;
}
if (nr_cpus > 0)
cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
else if (*cpu_list != '\0') {
pr_warning("Unexpected characters at end of cpu list ('%s'), using online CPUs.",
cpu_list);
cpus = perf_cpu_map__new_online_cpus();
} else
cpus = perf_cpu_map__new_any_cpu();
invalid:
free(tmp_cpus);
out:
return cpus;
}
static 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 result = {
.cpu = -1
};
if (cpus && idx < __perf_cpu_map__nr(cpus))
return __perf_cpu_map__cpu(cpus, idx);
return result;
}
int perf_cpu_map__nr(const struct perf_cpu_map *cpus)
{
return cpus ? __perf_cpu_map__nr(cpus) : 1;
}
bool perf_cpu_map__has_any_cpu_or_is_empty(const struct perf_cpu_map *map)
{
return map ? __perf_cpu_map__cpu(map, 0).cpu == -1 : true;
}
bool perf_cpu_map__is_any_cpu_or_is_empty(const struct perf_cpu_map *map)
{
if (!map)
return true;
return __perf_cpu_map__nr(map) == 1 && __perf_cpu_map__cpu(map, 0).cpu == -1;
}
bool perf_cpu_map__is_empty(const struct perf_cpu_map *map)
{
return map == NULL;
}
int perf_cpu_map__idx(const struct perf_cpu_map *cpus, struct perf_cpu cpu)
{
int low, high;
if (!cpus)
return -1;
low = 0;
high = __perf_cpu_map__nr(cpus);
while (low < high) {
int idx = (low + high) / 2;
struct perf_cpu cpu_at_idx = __perf_cpu_map__cpu(cpus, idx);
if (cpu_at_idx.cpu == cpu.cpu)
return idx;
if (cpu_at_idx.cpu > cpu.cpu)
high = idx;
else
low = idx + 1;
}
return -1;
}
bool perf_cpu_map__has(const struct perf_cpu_map *cpus, struct perf_cpu cpu)
{
return perf_cpu_map__idx(cpus, cpu) != -1;
}
bool perf_cpu_map__equal(const struct perf_cpu_map *lhs, const struct perf_cpu_map *rhs)
{
int nr;
if (lhs == rhs)
return true;
if (!lhs || !rhs)
return false;
nr = __perf_cpu_map__nr(lhs);
if (nr != __perf_cpu_map__nr(rhs))
return false;
for (int idx = 0; idx < nr; idx++) {
if (__perf_cpu_map__cpu(lhs, idx).cpu != __perf_cpu_map__cpu(rhs, idx).cpu)
return false;
}
return true;
}
bool perf_cpu_map__has_any_cpu(const struct perf_cpu_map *map)
{
return map && __perf_cpu_map__cpu(map, 0).cpu == -1;
}
struct perf_cpu perf_cpu_map__min(const struct perf_cpu_map *map)
{
struct perf_cpu cpu, result = {
.cpu = -1
};
int idx;
perf_cpu_map__for_each_cpu_skip_any(cpu, idx, map) {
result = cpu;
break;
}
return result;
}
struct perf_cpu perf_cpu_map__max(const struct perf_cpu_map *map)
{
struct perf_cpu result = {
.cpu = -1
};
// cpu_map__trim_new() qsort()s it, cpu_map__default_new() sorts it as well.
return __perf_cpu_map__nr(map) > 0
? __perf_cpu_map__cpu(map, __perf_cpu_map__nr(map) - 1)
: result;
}
/** Is 'b' a subset of 'a'. */
bool perf_cpu_map__is_subset(const struct perf_cpu_map *a, const struct perf_cpu_map *b)
{
if (a == b || !b)
return true;
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++) {
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) {
j++;
if (j == __perf_cpu_map__nr(b))
return true;
}
}
return false;
}
/*
* Merge two cpumaps
*
* orig either gets freed and replaced with a new map, or reused
* with no reference count change (similar to "realloc")
* other has its reference count increased.
*/
struct perf_cpu_map *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;
struct perf_cpu_map *merged;
if (perf_cpu_map__is_subset(orig, other))
return orig;
if (perf_cpu_map__is_subset(other, orig)) {
perf_cpu_map__put(orig);
return perf_cpu_map__get(other);
}
tmp_len = __perf_cpu_map__nr(orig) + __perf_cpu_map__nr(other);
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 < __perf_cpu_map__nr(orig) && j < __perf_cpu_map__nr(other)) {
if (__perf_cpu_map__cpu(orig, i).cpu <= __perf_cpu_map__cpu(other, j).cpu) {
if (__perf_cpu_map__cpu(orig, i).cpu == __perf_cpu_map__cpu(other, j).cpu)
j++;
tmp_cpus[k++] = __perf_cpu_map__cpu(orig, i++);
} else
tmp_cpus[k++] = __perf_cpu_map__cpu(other, j++);
}
while (i < __perf_cpu_map__nr(orig))
tmp_cpus[k++] = __perf_cpu_map__cpu(orig, i++);
while (j < __perf_cpu_map__nr(other))
tmp_cpus[k++] = __perf_cpu_map__cpu(other, j++);
assert(k <= tmp_len);
merged = cpu_map__trim_new(k, tmp_cpus);
free(tmp_cpus);
perf_cpu_map__put(orig);
return merged;
}
struct perf_cpu_map *perf_cpu_map__intersect(struct perf_cpu_map *orig,
struct perf_cpu_map *other)
{
struct perf_cpu *tmp_cpus;
int tmp_len;
int i, j, k;
struct perf_cpu_map *merged = NULL;
if (perf_cpu_map__is_subset(other, orig))
return perf_cpu_map__get(orig);
if (perf_cpu_map__is_subset(orig, other))
return perf_cpu_map__get(other);
tmp_len = max(__perf_cpu_map__nr(orig), __perf_cpu_map__nr(other));
tmp_cpus = malloc(tmp_len * sizeof(struct perf_cpu));
if (!tmp_cpus)
return NULL;
i = j = k = 0;
while (i < __perf_cpu_map__nr(orig) && j < __perf_cpu_map__nr(other)) {
if (__perf_cpu_map__cpu(orig, i).cpu < __perf_cpu_map__cpu(other, j).cpu)
i++;
else if (__perf_cpu_map__cpu(orig, i).cpu > __perf_cpu_map__cpu(other, j).cpu)
j++;
else {
j++;
tmp_cpus[k++] = __perf_cpu_map__cpu(orig, i++);
}
}
if (k)
merged = cpu_map__trim_new(k, tmp_cpus);
free(tmp_cpus);
return merged;
}