diff options
Diffstat (limited to 'tools/testing/selftests/acct')
| -rw-r--r-- | tools/testing/selftests/acct/.gitignore | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/acct/Makefile | 5 | ||||
| -rw-r--r-- | tools/testing/selftests/acct/acct_syscall.c | 2 | ||||
| -rw-r--r-- | tools/testing/selftests/acct/taskstats_fill_stats_tgid.c | 375 |
4 files changed, 382 insertions, 3 deletions
diff --git a/tools/testing/selftests/acct/.gitignore b/tools/testing/selftests/acct/.gitignore index 7e78aac19038..9e9c61c5bfd6 100644 --- a/tools/testing/selftests/acct/.gitignore +++ b/tools/testing/selftests/acct/.gitignore @@ -1,3 +1,4 @@ acct_syscall +taskstats_fill_stats_tgid config -process_log
\ No newline at end of file +process_log diff --git a/tools/testing/selftests/acct/Makefile b/tools/testing/selftests/acct/Makefile index 7e025099cf65..083cab5ddb72 100644 --- a/tools/testing/selftests/acct/Makefile +++ b/tools/testing/selftests/acct/Makefile @@ -1,5 +1,8 @@ # SPDX-License-Identifier: GPL-2.0 TEST_GEN_PROGS := acct_syscall +TEST_GEN_PROGS += taskstats_fill_stats_tgid + CFLAGS += -Wall +LDLIBS += -lpthread -include ../lib.mk
\ No newline at end of file +include ../lib.mk diff --git a/tools/testing/selftests/acct/acct_syscall.c b/tools/testing/selftests/acct/acct_syscall.c index 87c044fb9293..421adbdc299d 100644 --- a/tools/testing/selftests/acct/acct_syscall.c +++ b/tools/testing/selftests/acct/acct_syscall.c @@ -9,7 +9,7 @@ #include <string.h> #include <sys/wait.h> -#include "../kselftest.h" +#include "kselftest.h" int main(void) { diff --git a/tools/testing/selftests/acct/taskstats_fill_stats_tgid.c b/tools/testing/selftests/acct/taskstats_fill_stats_tgid.c new file mode 100644 index 000000000000..d6cab4ae26f2 --- /dev/null +++ b/tools/testing/selftests/acct/taskstats_fill_stats_tgid.c @@ -0,0 +1,375 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE + +#include <errno.h> +#include <linux/genetlink.h> +#include <linux/netlink.h> +#include <linux/taskstats.h> +#include <pthread.h> +#include <stdbool.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/socket.h> +#include <sys/types.h> +#include <time.h> +#include <unistd.h> + +#include "kselftest.h" + +#ifndef NLA_ALIGN +#define NLA_ALIGNTO 4 +#define NLA_ALIGN(len) (((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1)) +#define NLA_HDRLEN ((int)NLA_ALIGN(sizeof(struct nlattr))) +#endif + +#define BUSY_NS (200ULL * 1000 * 1000) + +struct worker_ctx { + pthread_mutex_t lock; + pthread_cond_t cond; + bool ready; + bool release; +}; + +static unsigned long busy_sink; + +static void *taskstats_nla_data(const struct nlattr *na) +{ + return (void *)((char *)na + NLA_HDRLEN); +} + +static bool taskstats_nla_ok(const struct nlattr *na, int remaining) +{ + return remaining >= (int)sizeof(*na) && + na->nla_len >= sizeof(*na) && + na->nla_len <= remaining; +} + +static struct nlattr *taskstats_nla_next(const struct nlattr *na, int *remaining) +{ + int aligned_len = NLA_ALIGN(na->nla_len); + + *remaining -= aligned_len; + return (struct nlattr *)((char *)na + aligned_len); +} + +static uint64_t timespec_diff_ns(const struct timespec *start, + const struct timespec *end) +{ + return (uint64_t)(end->tv_sec - start->tv_sec) * 1000000000ULL + + (uint64_t)(end->tv_nsec - start->tv_nsec); +} + +static void burn_cpu_for_ns(uint64_t runtime_ns) +{ + struct timespec start, now; + unsigned long acc = 0; + + if (clock_gettime(CLOCK_MONOTONIC, &start)) { + perror("clock_gettime"); + exit(EXIT_FAILURE); + } + + do { + for (int i = 0; i < 100000; i++) + acc += i; + if (clock_gettime(CLOCK_MONOTONIC, &now)) { + perror("clock_gettime"); + exit(EXIT_FAILURE); + } + } while (timespec_diff_ns(&start, &now) < runtime_ns); + + busy_sink = acc; +} + +static int netlink_open(void) +{ + struct sockaddr_nl addr = { + .nl_family = AF_NETLINK, + .nl_pid = getpid(), + }; + int fd; + + fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC); + if (fd < 0) + return -errno; + + if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) { + int err = -errno; + + close(fd); + return err; + } + + return fd; +} + +static int send_request(int fd, void *buf, size_t len) +{ + struct sockaddr_nl addr = { + .nl_family = AF_NETLINK, + }; + + if (sendto(fd, buf, len, 0, (struct sockaddr *)&addr, sizeof(addr)) < 0) + return -errno; + + return 0; +} + +static int get_family_id(int fd, const char *name) +{ + struct { + struct nlmsghdr nlh; + struct genlmsghdr genl; + char buf[256]; + } req = { 0 }; + char resp[8192]; + struct nlmsghdr *nlh; + struct genlmsghdr *genl; + struct nlattr *na; + int len; + int rem; + int ret; + + req.nlh.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN); + req.nlh.nlmsg_type = GENL_ID_CTRL; + req.nlh.nlmsg_flags = NLM_F_REQUEST; + req.nlh.nlmsg_seq = 1; + req.nlh.nlmsg_pid = getpid(); + + req.genl.cmd = CTRL_CMD_GETFAMILY; + req.genl.version = 1; + + na = (struct nlattr *)((char *)&req + NLMSG_ALIGN(req.nlh.nlmsg_len)); + na->nla_type = CTRL_ATTR_FAMILY_NAME; + na->nla_len = NLA_HDRLEN + strlen(name) + 1; + memcpy(taskstats_nla_data(na), name, strlen(name) + 1); + req.nlh.nlmsg_len = NLMSG_ALIGN(req.nlh.nlmsg_len) + NLA_ALIGN(na->nla_len); + + ret = send_request(fd, &req, req.nlh.nlmsg_len); + if (ret) + return ret; + + len = recv(fd, resp, sizeof(resp), 0); + if (len < 0) + return -errno; + + for (nlh = (struct nlmsghdr *)resp; NLMSG_OK(nlh, len); + nlh = NLMSG_NEXT(nlh, len)) { + if (nlh->nlmsg_type == NLMSG_ERROR) { + struct nlmsgerr *err = NLMSG_DATA(nlh); + + return err->error ? err->error : -ENOENT; + } + + genl = (struct genlmsghdr *)NLMSG_DATA(nlh); + rem = nlh->nlmsg_len - NLMSG_HDRLEN - GENL_HDRLEN; + na = (struct nlattr *)((char *)genl + GENL_HDRLEN); + while (taskstats_nla_ok(na, rem)) { + if (na->nla_type == CTRL_ATTR_FAMILY_ID) + return *(uint16_t *)taskstats_nla_data(na); + na = taskstats_nla_next(na, &rem); + } + } + + return -ENOENT; +} + +static int get_taskstats(int fd, int family_id, uint16_t attr_type, uint32_t id, + struct taskstats *stats) +{ + struct { + struct nlmsghdr nlh; + struct genlmsghdr genl; + char buf[256]; + } req = { 0 }; + char resp[16384]; + struct nlmsghdr *nlh; + struct genlmsghdr *genl; + struct nlattr *na; + struct nlattr *nested; + int len; + int rem; + int nrem; + int ret; + + memset(stats, 0, sizeof(*stats)); + + req.nlh.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN); + req.nlh.nlmsg_type = family_id; + req.nlh.nlmsg_flags = NLM_F_REQUEST; + req.nlh.nlmsg_seq = 2; + req.nlh.nlmsg_pid = getpid(); + + req.genl.cmd = TASKSTATS_CMD_GET; + req.genl.version = 1; + + na = (struct nlattr *)((char *)&req + NLMSG_ALIGN(req.nlh.nlmsg_len)); + na->nla_type = attr_type; + na->nla_len = NLA_HDRLEN + sizeof(id); + memcpy(taskstats_nla_data(na), &id, sizeof(id)); + req.nlh.nlmsg_len = NLMSG_ALIGN(req.nlh.nlmsg_len) + NLA_ALIGN(na->nla_len); + + ret = send_request(fd, &req, req.nlh.nlmsg_len); + if (ret) + return ret; + + len = recv(fd, resp, sizeof(resp), 0); + if (len < 0) + return -errno; + + for (nlh = (struct nlmsghdr *)resp; NLMSG_OK(nlh, len); + nlh = NLMSG_NEXT(nlh, len)) { + if (nlh->nlmsg_type == NLMSG_ERROR) { + struct nlmsgerr *err = NLMSG_DATA(nlh); + + return err->error ? err->error : -ENOENT; + } + + genl = (struct genlmsghdr *)NLMSG_DATA(nlh); + rem = nlh->nlmsg_len - NLMSG_HDRLEN - GENL_HDRLEN; + na = (struct nlattr *)((char *)genl + GENL_HDRLEN); + while (taskstats_nla_ok(na, rem)) { + if (na->nla_type == TASKSTATS_TYPE_AGGR_PID || + na->nla_type == TASKSTATS_TYPE_AGGR_TGID) { + nested = (struct nlattr *)taskstats_nla_data(na); + nrem = na->nla_len - NLA_HDRLEN; + while (taskstats_nla_ok(nested, nrem)) { + if (nested->nla_type == TASKSTATS_TYPE_STATS) { + memcpy(stats, taskstats_nla_data(nested), + sizeof(*stats)); + return 0; + } + nested = taskstats_nla_next(nested, &nrem); + } + } + na = taskstats_nla_next(na, &rem); + } + } + + return -ENOENT; +} + +static uint64_t cpu_total(const struct taskstats *stats) +{ + return (uint64_t)stats->ac_utime + (uint64_t)stats->ac_stime; +} + +static void print_stats(const char *label, const struct taskstats *stats) +{ + ksft_print_msg("%s: cpu_total=%llu nvcsw=%llu nivcsw=%llu\n", + label, (unsigned long long)cpu_total(stats), + (unsigned long long)stats->nvcsw, + (unsigned long long)stats->nivcsw); +} + +static void *worker_thread(void *arg) +{ + struct worker_ctx *ctx = arg; + + burn_cpu_for_ns(BUSY_NS); + + pthread_mutex_lock(&ctx->lock); + ctx->ready = true; + pthread_cond_broadcast(&ctx->cond); + while (!ctx->release) + pthread_cond_wait(&ctx->cond, &ctx->lock); + pthread_mutex_unlock(&ctx->lock); + + return NULL; +} + +int main(void) +{ + struct worker_ctx ctx = { + .lock = PTHREAD_MUTEX_INITIALIZER, + .cond = PTHREAD_COND_INITIALIZER, + }; + struct taskstats before, after; + pthread_t thread; + pid_t tgid = getpid(); + int family_id; + int fd; + int ret; + + ksft_print_header(); + ksft_set_plan(1); + + if (geteuid()) + ksft_exit_skip("taskstats_fill_stats_tgid needs root\n"); + + fd = netlink_open(); + if (fd < 0) + ksft_exit_skip("failed to open generic netlink socket: %s\n", + strerror(-fd)); + + family_id = get_family_id(fd, TASKSTATS_GENL_NAME); + if (family_id < 0) + ksft_exit_skip("taskstats generic netlink family unavailable: %s\n", + strerror(-family_id)); + + /* Create worker thread that burns 200ms of CPU */ + if (pthread_create(&thread, NULL, worker_thread, &ctx) != 0) + ksft_exit_fail_msg("pthread_create failed: %s\n", strerror(errno)); + + /* Wait for worker to finish generating activity */ + pthread_mutex_lock(&ctx.lock); + while (!ctx.ready) + pthread_cond_wait(&ctx.cond, &ctx.lock); + pthread_mutex_unlock(&ctx.lock); + + /* + * Snapshot A: TGID stats while worker is alive and sleeping. + * Contains main thread + worker contributions. + */ + ret = get_taskstats(fd, family_id, TASKSTATS_CMD_ATTR_TGID, tgid, &before); + if (ret) + ksft_exit_fail_msg("TGID query before exit failed: %s\n", + strerror(-ret)); + + /* Release worker so it can exit, then join (deterministic wait). + * + * Kernel exit path ordering guarantees: + * do_exit() + * taskstats_exit() -> fill_tgid_exit() (accumulates worker into signal->stats) + * exit_notify() (releases the thread) + * do_task_dead() -> __schedule() (wakes joiner) + * + * So pthread_join() returns only after fill_tgid_exit() has completed. + */ + pthread_mutex_lock(&ctx.lock); + ctx.release = true; + pthread_cond_broadcast(&ctx.cond); + pthread_mutex_unlock(&ctx.lock); + + pthread_join(thread, NULL); + + /* + * Snapshot B: TGID stats after worker has exited. + * fill_stats_for_tgid() does: + * memcpy(signal->stats) <- includes fill_tgid_exit accumulation + * + scan live threads <- only main thread now + */ + ret = get_taskstats(fd, family_id, TASKSTATS_CMD_ATTR_TGID, tgid, &after); + if (ret) + ksft_exit_fail_msg("TGID query after exit failed: %s\n", + strerror(-ret)); + + print_stats("TGID before worker exit", &before); + print_stats("TGID after worker exit", &after); + + /* + * The worker burned 200ms of CPU before the first snapshot. + * If the kernel correctly retained its contribution via + * fill_tgid_exit(), then the TGID CPU total after exit must be at + * least as large as the TGID CPU total before exit. + */ + ksft_test_result(cpu_total(&after) >= cpu_total(&before), + "TGID CPU stats should not regress after thread exit\n"); + + close(fd); + ksft_finished(); + return ksft_get_fail_cnt() ? KSFT_FAIL : KSFT_PASS; +} |