From: Ian Rogers Date: Tue, 24 Jun 2025 19:03:23 +0000 (-0700) Subject: perf hwmon_pmu: Hold path rather than fd X-Git-Tag: io_uring-6.17-20250815~64^2~100 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=d1f18106778b4d1af5ca6bde191e05e075c7e697;p=linux-block.git perf hwmon_pmu: Hold path rather than fd Hold the path to the hwmon_pmu rather than the file descriptor. The file descriptor is somewhat problematic in that it reflects the directory state when opened, something that may vary in testing. Using a path simplifies testing and to some extent cleanup as the hwmon_pmu is owned by the pmus list and intentionally global and leaked when perf terminates, the file descriptor being left open looks like a leak. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250624190326.2038704-4-irogers@google.com Signed-off-by: Namhyung Kim --- diff --git a/tools/perf/tests/hwmon_pmu.c b/tools/perf/tests/hwmon_pmu.c index 0837aca1cdfa..151f02701c8c 100644 --- a/tools/perf/tests/hwmon_pmu.c +++ b/tools/perf/tests/hwmon_pmu.c @@ -93,9 +93,10 @@ static struct perf_pmu *test_pmu_get(char *dir, size_t sz) pr_err("Failed to mkdir hwmon directory\n"); goto err_out; } - hwmon_dirfd = openat(test_dirfd, "hwmon1234", O_DIRECTORY); + strncat(dir, "/hwmon1234", sz - strlen(dir)); + hwmon_dirfd = open(dir, O_PATH|O_DIRECTORY); if (hwmon_dirfd < 0) { - pr_err("Failed to open test hwmon directory \"%s/hwmon1234\"\n", dir); + pr_err("Failed to open test hwmon directory \"%s\"\n", dir); goto err_out; } file = openat(hwmon_dirfd, "name", O_WRONLY | O_CREAT, 0600); @@ -130,18 +131,18 @@ static struct perf_pmu *test_pmu_get(char *dir, size_t sz) } /* Make the PMU reading the files created above. */ - hwm = perf_pmus__add_test_hwmon_pmu(hwmon_dirfd, "hwmon1234", test_hwmon_name); + hwm = perf_pmus__add_test_hwmon_pmu(dir, "hwmon1234", test_hwmon_name); if (!hwm) pr_err("Test hwmon creation failed\n"); err_out: if (!hwm) { test_pmu_put(dir, hwm); - if (hwmon_dirfd >= 0) - close(hwmon_dirfd); } if (test_dirfd >= 0) close(test_dirfd); + if (hwmon_dirfd >= 0) + close(hwmon_dirfd); return hwm; } diff --git a/tools/perf/util/hwmon_pmu.c b/tools/perf/util/hwmon_pmu.c index c25e7296f1c1..7edda010ba27 100644 --- a/tools/perf/util/hwmon_pmu.c +++ b/tools/perf/util/hwmon_pmu.c @@ -104,7 +104,7 @@ static const char *const hwmon_units[HWMON_TYPE_MAX] = { struct hwmon_pmu { struct perf_pmu pmu; struct hashmap events; - int hwmon_dir_fd; + char *hwmon_dir; }; /** @@ -245,7 +245,7 @@ static int hwmon_pmu__read_events(struct hwmon_pmu *pmu) return 0; /* Use openat so that the directory contents are refreshed. */ - io_dir__init(&dir, openat(pmu->hwmon_dir_fd, ".", O_CLOEXEC | O_DIRECTORY | O_RDONLY)); + io_dir__init(&dir, open(pmu->hwmon_dir, O_CLOEXEC | O_DIRECTORY | O_RDONLY)); if (dir.dirfd < 0) return -ENOENT; @@ -283,7 +283,7 @@ static int hwmon_pmu__read_events(struct hwmon_pmu *pmu) __set_bit(item, alarm ? value->alarm_items : value->items); if (item == HWMON_ITEM_LABEL) { char buf[128]; - int fd = openat(pmu->hwmon_dir_fd, ent->d_name, O_RDONLY); + int fd = openat(dir.dirfd, ent->d_name, O_RDONLY); ssize_t read_len; if (fd < 0) @@ -342,7 +342,8 @@ err_out: return err; } -struct perf_pmu *hwmon_pmu__new(struct list_head *pmus, int hwmon_dir, const char *sysfs_name, const char *name) +struct perf_pmu *hwmon_pmu__new(struct list_head *pmus, const char *hwmon_dir, + const char *sysfs_name, const char *name) { char buf[32]; struct hwmon_pmu *hwm; @@ -365,7 +366,11 @@ struct perf_pmu *hwmon_pmu__new(struct list_head *pmus, int hwmon_dir, const cha return NULL; } - hwm->hwmon_dir_fd = hwmon_dir; + hwm->hwmon_dir = strdup(hwmon_dir); + if (!hwm->hwmon_dir) { + perf_pmu__delete(&hwm->pmu); + return NULL; + } hwm->pmu.alias_name = strdup(sysfs_name); if (!hwm->pmu.alias_name) { perf_pmu__delete(&hwm->pmu); @@ -399,7 +404,7 @@ void hwmon_pmu__exit(struct perf_pmu *pmu) free(value); } hashmap__clear(&hwm->events); - close(hwm->hwmon_dir_fd); + zfree(&hwm->hwmon_dir); } static size_t hwmon_pmu__describe_items(struct hwmon_pmu *hwm, char *out_buf, size_t out_buf_len, @@ -409,6 +414,10 @@ static size_t hwmon_pmu__describe_items(struct hwmon_pmu *hwm, char *out_buf, si size_t bit; char buf[64]; size_t len = 0; + int dir = open(hwm->hwmon_dir, O_CLOEXEC | O_DIRECTORY | O_RDONLY); + + if (dir < 0) + return 0; for_each_set_bit(bit, items, HWMON_ITEM__MAX) { int fd; @@ -421,7 +430,7 @@ static size_t hwmon_pmu__describe_items(struct hwmon_pmu *hwm, char *out_buf, si key.num, hwmon_item_strs[bit], is_alarm ? "_alarm" : ""); - fd = openat(hwm->hwmon_dir_fd, buf, O_RDONLY); + fd = openat(dir, buf, O_RDONLY); if (fd > 0) { ssize_t read_len = read(fd, buf, sizeof(buf)); @@ -443,6 +452,7 @@ static size_t hwmon_pmu__describe_items(struct hwmon_pmu *hwm, char *out_buf, si close(fd); } } + close(dir); return len; } @@ -712,6 +722,7 @@ int perf_pmus__read_hwmon_pmus(struct list_head *pmus) size_t line_len; int hwmon_dir, name_fd; struct io io; + char buf2[128]; if (class_hwmon_ent->d_type != DT_LNK) continue; @@ -730,12 +741,13 @@ int perf_pmus__read_hwmon_pmus(struct list_head *pmus) close(hwmon_dir); continue; } - io__init(&io, name_fd, buf, sizeof(buf)); + io__init(&io, name_fd, buf2, sizeof(buf2)); io__getline(&io, &line, &line_len); if (line_len > 0 && line[line_len - 1] == '\n') line[line_len - 1] = '\0'; - hwmon_pmu__new(pmus, hwmon_dir, class_hwmon_ent->d_name, line); + hwmon_pmu__new(pmus, buf, class_hwmon_ent->d_name, line); close(name_fd); + close(hwmon_dir); } free(line); close(class_hwmon_dir.dirfd); @@ -753,6 +765,10 @@ int evsel__hwmon_pmu_open(struct evsel *evsel, .type_and_num = evsel->core.attr.config, }; int idx = 0, thread = 0, nthreads, err = 0; + int dir = open(hwm->hwmon_dir, O_CLOEXEC | O_DIRECTORY | O_RDONLY); + + if (dir < 0) + return -errno; nthreads = perf_thread_map__nr(threads); for (idx = start_cpu_map_idx; idx < end_cpu_map_idx; idx++) { @@ -763,7 +779,7 @@ int evsel__hwmon_pmu_open(struct evsel *evsel, snprintf(buf, sizeof(buf), "%s%d_input", hwmon_type_strs[key.type], key.num); - fd = openat(hwm->hwmon_dir_fd, buf, O_RDONLY); + fd = openat(dir, buf, O_RDONLY); FD(evsel, idx, thread) = fd; if (fd < 0) { err = -errno; @@ -771,6 +787,7 @@ int evsel__hwmon_pmu_open(struct evsel *evsel, } } } + close(dir); return 0; out_close: if (err) @@ -784,6 +801,7 @@ out_close: } thread = nthreads; } while (--idx >= 0); + close(dir); return err; } diff --git a/tools/perf/util/hwmon_pmu.h b/tools/perf/util/hwmon_pmu.h index b3329774d2b2..dc711b289ff5 100644 --- a/tools/perf/util/hwmon_pmu.h +++ b/tools/perf/util/hwmon_pmu.h @@ -135,14 +135,14 @@ bool parse_hwmon_filename(const char *filename, * hwmon_pmu__new() - Allocate and construct a hwmon PMU. * * @pmus: The list of PMUs to be added to. - * @hwmon_dir: An O_DIRECTORY file descriptor for a hwmon directory. + * @hwmon_dir: The path to a hwmon directory. * @sysfs_name: Name of the hwmon sysfs directory like hwmon0. * @name: The contents of the "name" file in the hwmon directory. * * Exposed for testing. Regular construction should happen via * perf_pmus__read_hwmon_pmus. */ -struct perf_pmu *hwmon_pmu__new(struct list_head *pmus, int hwmon_dir, +struct perf_pmu *hwmon_pmu__new(struct list_head *pmus, const char *hwmon_dir, const char *sysfs_name, const char *name); void hwmon_pmu__exit(struct perf_pmu *pmu); diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c index 81c2ed689db2..409b909cfa02 100644 --- a/tools/perf/util/pmus.c +++ b/tools/perf/util/pmus.c @@ -861,7 +861,7 @@ struct perf_pmu *perf_pmus__add_test_pmu(int test_sysfs_dirfd, const char *name) return perf_pmu__lookup(&other_pmus, test_sysfs_dirfd, name, /*eager_load=*/true); } -struct perf_pmu *perf_pmus__add_test_hwmon_pmu(int hwmon_dir, +struct perf_pmu *perf_pmus__add_test_hwmon_pmu(const char *hwmon_dir, const char *sysfs_name, const char *name) { diff --git a/tools/perf/util/pmus.h b/tools/perf/util/pmus.h index 33ecf765a92f..86842ee5f539 100644 --- a/tools/perf/util/pmus.h +++ b/tools/perf/util/pmus.h @@ -31,7 +31,7 @@ int perf_pmus__num_core_pmus(void); bool perf_pmus__supports_extended_type(void); struct perf_pmu *perf_pmus__add_test_pmu(int test_sysfs_dirfd, const char *name); -struct perf_pmu *perf_pmus__add_test_hwmon_pmu(int hwmon_dir, +struct perf_pmu *perf_pmus__add_test_hwmon_pmu(const char *hwmon_dir, const char *sysfs_name, const char *name); struct perf_pmu *perf_pmus__fake_pmu(void);