summaryrefslogtreecommitdiffstats
path: root/tools/testing/selftests/perf_events
diff options
context:
space:
mode:
Diffstat (limited to 'tools/testing/selftests/perf_events')
-rw-r--r--tools/testing/selftests/perf_events/.gitignore3
-rw-r--r--tools/testing/selftests/perf_events/Makefile6
-rw-r--r--tools/testing/selftests/perf_events/config1
-rw-r--r--tools/testing/selftests/perf_events/remove_on_exec.c260
-rw-r--r--tools/testing/selftests/perf_events/settings1
-rw-r--r--tools/testing/selftests/perf_events/sigtrap_threads.c240
6 files changed, 511 insertions, 0 deletions
diff --git a/tools/testing/selftests/perf_events/.gitignore b/tools/testing/selftests/perf_events/.gitignore
new file mode 100644
index 000000000..790c47001
--- /dev/null
+++ b/tools/testing/selftests/perf_events/.gitignore
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+sigtrap_threads
+remove_on_exec
diff --git a/tools/testing/selftests/perf_events/Makefile b/tools/testing/selftests/perf_events/Makefile
new file mode 100644
index 000000000..db93c4ff0
--- /dev/null
+++ b/tools/testing/selftests/perf_events/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+CFLAGS += -Wl,-no-as-needed -Wall $(KHDR_INCLUDES)
+LDFLAGS += -lpthread
+
+TEST_GEN_PROGS := sigtrap_threads remove_on_exec
+include ../lib.mk
diff --git a/tools/testing/selftests/perf_events/config b/tools/testing/selftests/perf_events/config
new file mode 100644
index 000000000..ba58ff220
--- /dev/null
+++ b/tools/testing/selftests/perf_events/config
@@ -0,0 +1 @@
+CONFIG_PERF_EVENTS=y
diff --git a/tools/testing/selftests/perf_events/remove_on_exec.c b/tools/testing/selftests/perf_events/remove_on_exec.c
new file mode 100644
index 000000000..5814611a1
--- /dev/null
+++ b/tools/testing/selftests/perf_events/remove_on_exec.c
@@ -0,0 +1,260 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test for remove_on_exec.
+ *
+ * Copyright (C) 2021, Google LLC.
+ */
+
+#define _GNU_SOURCE
+
+/* We need the latest siginfo from the kernel repo. */
+#include <sys/types.h>
+#include <asm/siginfo.h>
+#define __have_siginfo_t 1
+#define __have_sigval_t 1
+#define __have_sigevent_t 1
+#define __siginfo_t_defined
+#define __sigval_t_defined
+#define __sigevent_t_defined
+#define _BITS_SIGINFO_CONSTS_H 1
+#define _BITS_SIGEVENT_CONSTS_H 1
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <linux/perf_event.h>
+#include <pthread.h>
+#include <signal.h>
+#include <sys/ioctl.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#include "../kselftest_harness.h"
+
+static volatile int signal_count;
+
+static struct perf_event_attr make_event_attr(void)
+{
+ struct perf_event_attr attr = {
+ .type = PERF_TYPE_HARDWARE,
+ .size = sizeof(attr),
+ .config = PERF_COUNT_HW_INSTRUCTIONS,
+ .sample_period = 1000,
+ .exclude_kernel = 1,
+ .exclude_hv = 1,
+ .disabled = 1,
+ .inherit = 1,
+ /*
+ * Children normally retain their inherited event on exec; with
+ * remove_on_exec, we'll remove their event, but the parent and
+ * any other non-exec'd children will keep their events.
+ */
+ .remove_on_exec = 1,
+ .sigtrap = 1,
+ };
+ return attr;
+}
+
+static void sigtrap_handler(int signum, siginfo_t *info, void *ucontext)
+{
+ if (info->si_code != TRAP_PERF) {
+ fprintf(stderr, "%s: unexpected si_code %d\n", __func__, info->si_code);
+ return;
+ }
+
+ signal_count++;
+}
+
+FIXTURE(remove_on_exec)
+{
+ struct sigaction oldact;
+ int fd;
+};
+
+FIXTURE_SETUP(remove_on_exec)
+{
+ struct perf_event_attr attr = make_event_attr();
+ struct sigaction action = {};
+
+ signal_count = 0;
+
+ /* Initialize sigtrap handler. */
+ action.sa_flags = SA_SIGINFO | SA_NODEFER;
+ action.sa_sigaction = sigtrap_handler;
+ sigemptyset(&action.sa_mask);
+ ASSERT_EQ(sigaction(SIGTRAP, &action, &self->oldact), 0);
+
+ /* Initialize perf event. */
+ self->fd = syscall(__NR_perf_event_open, &attr, 0, -1, -1, PERF_FLAG_FD_CLOEXEC);
+ ASSERT_NE(self->fd, -1);
+}
+
+FIXTURE_TEARDOWN(remove_on_exec)
+{
+ close(self->fd);
+ sigaction(SIGTRAP, &self->oldact, NULL);
+}
+
+/* Verify event propagates to fork'd child. */
+TEST_F(remove_on_exec, fork_only)
+{
+ int status;
+ pid_t pid = fork();
+
+ if (pid == 0) {
+ ASSERT_EQ(signal_count, 0);
+ ASSERT_EQ(ioctl(self->fd, PERF_EVENT_IOC_ENABLE, 0), 0);
+ while (!signal_count);
+ _exit(42);
+ }
+
+ while (!signal_count); /* Child enables event. */
+ EXPECT_EQ(waitpid(pid, &status, 0), pid);
+ EXPECT_EQ(WEXITSTATUS(status), 42);
+}
+
+/*
+ * Verify that event does _not_ propagate to fork+exec'd child; event enabled
+ * after fork+exec.
+ */
+TEST_F(remove_on_exec, fork_exec_then_enable)
+{
+ pid_t pid_exec, pid_only_fork;
+ int pipefd[2];
+ int tmp;
+
+ /*
+ * Non-exec child, to ensure exec does not affect inherited events of
+ * other children.
+ */
+ pid_only_fork = fork();
+ if (pid_only_fork == 0) {
+ /* Block until parent enables event. */
+ while (!signal_count);
+ _exit(42);
+ }
+
+ ASSERT_NE(pipe(pipefd), -1);
+ pid_exec = fork();
+ if (pid_exec == 0) {
+ ASSERT_NE(dup2(pipefd[1], STDOUT_FILENO), -1);
+ close(pipefd[0]);
+ execl("/proc/self/exe", "exec_child", NULL);
+ _exit((perror("exec failed"), 1));
+ }
+ close(pipefd[1]);
+
+ ASSERT_EQ(waitpid(pid_exec, &tmp, WNOHANG), 0); /* Child is running. */
+ /* Wait for exec'd child to start spinning. */
+ EXPECT_EQ(read(pipefd[0], &tmp, sizeof(int)), sizeof(int));
+ EXPECT_EQ(tmp, 42);
+ close(pipefd[0]);
+ /* Now we can enable the event, knowing the child is doing work. */
+ EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_ENABLE, 0), 0);
+ /* If the event propagated to the exec'd child, it will exit normally... */
+ usleep(100000); /* ... give time for event to trigger (in case of bug). */
+ EXPECT_EQ(waitpid(pid_exec, &tmp, WNOHANG), 0); /* Should still be running. */
+ EXPECT_EQ(kill(pid_exec, SIGKILL), 0);
+
+ /* Verify removal from child did not affect this task's event. */
+ tmp = signal_count;
+ while (signal_count == tmp); /* Should not hang! */
+ /* Nor should it have affected the first child. */
+ EXPECT_EQ(waitpid(pid_only_fork, &tmp, 0), pid_only_fork);
+ EXPECT_EQ(WEXITSTATUS(tmp), 42);
+}
+
+/*
+ * Verify that event does _not_ propagate to fork+exec'd child; event enabled
+ * before fork+exec.
+ */
+TEST_F(remove_on_exec, enable_then_fork_exec)
+{
+ pid_t pid_exec;
+ int tmp;
+
+ EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_ENABLE, 0), 0);
+
+ pid_exec = fork();
+ if (pid_exec == 0) {
+ execl("/proc/self/exe", "exec_child", NULL);
+ _exit((perror("exec failed"), 1));
+ }
+
+ /*
+ * The child may exit abnormally at any time if the event propagated and
+ * a SIGTRAP is sent before the handler was set up.
+ */
+ usleep(100000); /* ... give time for event to trigger (in case of bug). */
+ EXPECT_EQ(waitpid(pid_exec, &tmp, WNOHANG), 0); /* Should still be running. */
+ EXPECT_EQ(kill(pid_exec, SIGKILL), 0);
+
+ /* Verify removal from child did not affect this task's event. */
+ tmp = signal_count;
+ while (signal_count == tmp); /* Should not hang! */
+}
+
+TEST_F(remove_on_exec, exec_stress)
+{
+ pid_t pids[30];
+ int i, tmp;
+
+ for (i = 0; i < sizeof(pids) / sizeof(pids[0]); i++) {
+ pids[i] = fork();
+ if (pids[i] == 0) {
+ execl("/proc/self/exe", "exec_child", NULL);
+ _exit((perror("exec failed"), 1));
+ }
+
+ /* Some forked with event disabled, rest with enabled. */
+ if (i > 10)
+ EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_ENABLE, 0), 0);
+ }
+
+ usleep(100000); /* ... give time for event to trigger (in case of bug). */
+
+ for (i = 0; i < sizeof(pids) / sizeof(pids[0]); i++) {
+ /* All children should still be running. */
+ EXPECT_EQ(waitpid(pids[i], &tmp, WNOHANG), 0);
+ EXPECT_EQ(kill(pids[i], SIGKILL), 0);
+ }
+
+ /* Verify event is still alive. */
+ tmp = signal_count;
+ while (signal_count == tmp);
+}
+
+/* For exec'd child. */
+static void exec_child(void)
+{
+ struct sigaction action = {};
+ const int val = 42;
+
+ /* Set up sigtrap handler in case we erroneously receive a trap. */
+ action.sa_flags = SA_SIGINFO | SA_NODEFER;
+ action.sa_sigaction = sigtrap_handler;
+ sigemptyset(&action.sa_mask);
+ if (sigaction(SIGTRAP, &action, NULL))
+ _exit((perror("sigaction failed"), 1));
+
+ /* Signal parent that we're starting to spin. */
+ if (write(STDOUT_FILENO, &val, sizeof(int)) == -1)
+ _exit((perror("write failed"), 1));
+
+ /* Should hang here until killed. */
+ while (!signal_count);
+}
+
+#define main test_main
+TEST_HARNESS_MAIN
+#undef main
+int main(int argc, char *argv[])
+{
+ if (!strcmp(argv[0], "exec_child")) {
+ exec_child();
+ return 1;
+ }
+
+ return test_main(argc, argv);
+}
diff --git a/tools/testing/selftests/perf_events/settings b/tools/testing/selftests/perf_events/settings
new file mode 100644
index 000000000..6091b45d2
--- /dev/null
+++ b/tools/testing/selftests/perf_events/settings
@@ -0,0 +1 @@
+timeout=120
diff --git a/tools/testing/selftests/perf_events/sigtrap_threads.c b/tools/testing/selftests/perf_events/sigtrap_threads.c
new file mode 100644
index 000000000..d1d8483ac
--- /dev/null
+++ b/tools/testing/selftests/perf_events/sigtrap_threads.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test for perf events with SIGTRAP across all threads.
+ *
+ * Copyright (C) 2021, Google LLC.
+ */
+
+#define _GNU_SOURCE
+
+/* We need the latest siginfo from the kernel repo. */
+#include <sys/types.h>
+#include <asm/siginfo.h>
+#define __have_siginfo_t 1
+#define __have_sigval_t 1
+#define __have_sigevent_t 1
+#define __siginfo_t_defined
+#define __sigval_t_defined
+#define __sigevent_t_defined
+#define _BITS_SIGINFO_CONSTS_H 1
+#define _BITS_SIGEVENT_CONSTS_H 1
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <linux/hw_breakpoint.h>
+#include <linux/perf_event.h>
+#include <pthread.h>
+#include <signal.h>
+#include <sys/ioctl.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#include "../kselftest_harness.h"
+
+#define NUM_THREADS 5
+
+/* Data shared between test body, threads, and signal handler. */
+static struct {
+ int tids_want_signal; /* Which threads still want a signal. */
+ int signal_count; /* Sanity check number of signals received. */
+ volatile int iterate_on; /* Variable to set breakpoint on. */
+ siginfo_t first_siginfo; /* First observed siginfo_t. */
+} ctx;
+
+/* Unique value to check si_perf_data is correctly set from perf_event_attr::sig_data. */
+#define TEST_SIG_DATA(addr, id) (~(unsigned long)(addr) + id)
+
+static struct perf_event_attr make_event_attr(bool enabled, volatile void *addr,
+ unsigned long id)
+{
+ struct perf_event_attr attr = {
+ .type = PERF_TYPE_BREAKPOINT,
+ .size = sizeof(attr),
+ .sample_period = 1,
+ .disabled = !enabled,
+ .bp_addr = (unsigned long)addr,
+ .bp_type = HW_BREAKPOINT_RW,
+ .bp_len = HW_BREAKPOINT_LEN_1,
+ .inherit = 1, /* Children inherit events ... */
+ .inherit_thread = 1, /* ... but only cloned with CLONE_THREAD. */
+ .remove_on_exec = 1, /* Required by sigtrap. */
+ .sigtrap = 1, /* Request synchronous SIGTRAP on event. */
+ .sig_data = TEST_SIG_DATA(addr, id),
+ .exclude_kernel = 1, /* To allow */
+ .exclude_hv = 1, /* running as !root */
+ };
+ return attr;
+}
+
+static void sigtrap_handler(int signum, siginfo_t *info, void *ucontext)
+{
+ if (info->si_code != TRAP_PERF) {
+ fprintf(stderr, "%s: unexpected si_code %d\n", __func__, info->si_code);
+ return;
+ }
+
+ /*
+ * The data in siginfo_t we're interested in should all be the same
+ * across threads.
+ */
+ if (!__atomic_fetch_add(&ctx.signal_count, 1, __ATOMIC_RELAXED))
+ ctx.first_siginfo = *info;
+ __atomic_fetch_sub(&ctx.tids_want_signal, syscall(__NR_gettid), __ATOMIC_RELAXED);
+}
+
+static void *test_thread(void *arg)
+{
+ pthread_barrier_t *barrier = (pthread_barrier_t *)arg;
+ pid_t tid = syscall(__NR_gettid);
+ int iter;
+ int i;
+
+ pthread_barrier_wait(barrier);
+
+ __atomic_fetch_add(&ctx.tids_want_signal, tid, __ATOMIC_RELAXED);
+ iter = ctx.iterate_on; /* read */
+ if (iter >= 0) {
+ for (i = 0; i < iter - 1; i++) {
+ __atomic_fetch_add(&ctx.tids_want_signal, tid, __ATOMIC_RELAXED);
+ ctx.iterate_on = iter; /* idempotent write */
+ }
+ } else {
+ while (ctx.iterate_on);
+ }
+
+ return NULL;
+}
+
+FIXTURE(sigtrap_threads)
+{
+ struct sigaction oldact;
+ pthread_t threads[NUM_THREADS];
+ pthread_barrier_t barrier;
+ int fd;
+};
+
+FIXTURE_SETUP(sigtrap_threads)
+{
+ struct perf_event_attr attr = make_event_attr(false, &ctx.iterate_on, 0);
+ struct sigaction action = {};
+ int i;
+
+ memset(&ctx, 0, sizeof(ctx));
+
+ /* Initialize sigtrap handler. */
+ action.sa_flags = SA_SIGINFO | SA_NODEFER;
+ action.sa_sigaction = sigtrap_handler;
+ sigemptyset(&action.sa_mask);
+ ASSERT_EQ(sigaction(SIGTRAP, &action, &self->oldact), 0);
+
+ /* Initialize perf event. */
+ self->fd = syscall(__NR_perf_event_open, &attr, 0, -1, -1, PERF_FLAG_FD_CLOEXEC);
+ ASSERT_NE(self->fd, -1);
+
+ /* Spawn threads inheriting perf event. */
+ pthread_barrier_init(&self->barrier, NULL, NUM_THREADS + 1);
+ for (i = 0; i < NUM_THREADS; i++)
+ ASSERT_EQ(pthread_create(&self->threads[i], NULL, test_thread, &self->barrier), 0);
+}
+
+FIXTURE_TEARDOWN(sigtrap_threads)
+{
+ pthread_barrier_destroy(&self->barrier);
+ close(self->fd);
+ sigaction(SIGTRAP, &self->oldact, NULL);
+}
+
+static void run_test_threads(struct __test_metadata *_metadata,
+ FIXTURE_DATA(sigtrap_threads) *self)
+{
+ int i;
+
+ pthread_barrier_wait(&self->barrier);
+ for (i = 0; i < NUM_THREADS; i++)
+ ASSERT_EQ(pthread_join(self->threads[i], NULL), 0);
+}
+
+TEST_F(sigtrap_threads, remain_disabled)
+{
+ run_test_threads(_metadata, self);
+ EXPECT_EQ(ctx.signal_count, 0);
+ EXPECT_NE(ctx.tids_want_signal, 0);
+}
+
+TEST_F(sigtrap_threads, enable_event)
+{
+ EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_ENABLE, 0), 0);
+ run_test_threads(_metadata, self);
+
+ EXPECT_EQ(ctx.signal_count, NUM_THREADS);
+ EXPECT_EQ(ctx.tids_want_signal, 0);
+ EXPECT_EQ(ctx.first_siginfo.si_addr, &ctx.iterate_on);
+ EXPECT_EQ(ctx.first_siginfo.si_perf_type, PERF_TYPE_BREAKPOINT);
+ EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on, 0));
+
+ /* Check enabled for parent. */
+ ctx.iterate_on = 0;
+ EXPECT_EQ(ctx.signal_count, NUM_THREADS + 1);
+}
+
+/* Test that modification propagates to all inherited events. */
+TEST_F(sigtrap_threads, modify_and_enable_event)
+{
+ struct perf_event_attr new_attr = make_event_attr(true, &ctx.iterate_on, 42);
+
+ EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &new_attr), 0);
+ run_test_threads(_metadata, self);
+
+ EXPECT_EQ(ctx.signal_count, NUM_THREADS);
+ EXPECT_EQ(ctx.tids_want_signal, 0);
+ EXPECT_EQ(ctx.first_siginfo.si_addr, &ctx.iterate_on);
+ EXPECT_EQ(ctx.first_siginfo.si_perf_type, PERF_TYPE_BREAKPOINT);
+ EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on, 42));
+
+ /* Check enabled for parent. */
+ ctx.iterate_on = 0;
+ EXPECT_EQ(ctx.signal_count, NUM_THREADS + 1);
+}
+
+/* Stress test event + signal handling. */
+TEST_F(sigtrap_threads, signal_stress)
+{
+ ctx.iterate_on = 3000;
+
+ EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_ENABLE, 0), 0);
+ run_test_threads(_metadata, self);
+ EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_DISABLE, 0), 0);
+
+ EXPECT_EQ(ctx.signal_count, NUM_THREADS * ctx.iterate_on);
+ EXPECT_EQ(ctx.tids_want_signal, 0);
+ EXPECT_EQ(ctx.first_siginfo.si_addr, &ctx.iterate_on);
+ EXPECT_EQ(ctx.first_siginfo.si_perf_type, PERF_TYPE_BREAKPOINT);
+ EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on, 0));
+}
+
+TEST_F(sigtrap_threads, signal_stress_with_disable)
+{
+ const int target_count = NUM_THREADS * 3000;
+ int i;
+
+ ctx.iterate_on = -1;
+
+ EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_ENABLE, 0), 0);
+ pthread_barrier_wait(&self->barrier);
+ while (__atomic_load_n(&ctx.signal_count, __ATOMIC_RELAXED) < target_count) {
+ EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_DISABLE, 0), 0);
+ EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_ENABLE, 0), 0);
+ }
+ ctx.iterate_on = 0;
+ for (i = 0; i < NUM_THREADS; i++)
+ ASSERT_EQ(pthread_join(self->threads[i], NULL), 0);
+ EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_DISABLE, 0), 0);
+
+ EXPECT_EQ(ctx.first_siginfo.si_addr, &ctx.iterate_on);
+ EXPECT_EQ(ctx.first_siginfo.si_perf_type, PERF_TYPE_BREAKPOINT);
+ EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on, 0));
+}
+
+TEST_HARNESS_MAIN