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From: Marco Elver <elver@google.com>
To: elver@google.com, peterz@infradead.org,
	alexander.shishkin@linux.intel.com, acme@kernel.org,
	mingo@redhat.com, jolsa@redhat.com, mark.rutland@arm.com,
	namhyung@kernel.org, tglx@linutronix.de
Cc: glider@google.com, viro@zeniv.linux.org.uk, arnd@arndb.de,
	christian@brauner.io, dvyukov@google.com, jannh@google.com,
	axboe@kernel.dk, mascasa@google.com, pcc@google.com,
	irogers@google.com, oleg@redhat.com, kasan-dev@googlegroups.com,
	linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, x86@kernel.org,
	linux-kselftest@vger.kernel.org
Subject: [PATCH v4 10/10] perf test: Add basic stress test for sigtrap handling
Date: Thu,  8 Apr 2021 12:36:05 +0200	[thread overview]
Message-ID: <20210408103605.1676875-11-elver@google.com> (raw)
In-Reply-To: <20210408103605.1676875-1-elver@google.com>

Add basic stress test for sigtrap handling as a perf tool built-in test.
This allows sanity checking the basic sigtrap functionality from within
the perf tool.

Note: A more elaborate kselftest version of this test can also be found
in tools/testing/selftests/perf_events/sigtrap_threads.c.

Signed-off-by: Marco Elver <elver@google.com>
---
v4:
* Update for new perf_event_attr::sig_data / si_perf handling.

v3:
* Added to series (per suggestion from Ian Rogers).
---
 tools/perf/tests/Build          |   1 +
 tools/perf/tests/builtin-test.c |   5 ++
 tools/perf/tests/sigtrap.c      | 150 ++++++++++++++++++++++++++++++++
 tools/perf/tests/tests.h        |   1 +
 4 files changed, 157 insertions(+)
 create mode 100644 tools/perf/tests/sigtrap.c

diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build
index 650aec19d490..a429c7a02b37 100644
--- a/tools/perf/tests/Build
+++ b/tools/perf/tests/Build
@@ -64,6 +64,7 @@ perf-y += parse-metric.o
 perf-y += pe-file-parsing.o
 perf-y += expand-cgroup.o
 perf-y += perf-time-to-tsc.o
+perf-y += sigtrap.o
 
 $(OUTPUT)tests/llvm-src-base.c: tests/bpf-script-example.c tests/Build
 	$(call rule_mkdir)
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index c4b888f18e9c..28a1cb5eaa77 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -359,6 +359,11 @@ static struct test generic_tests[] = {
 		.func = test__perf_time_to_tsc,
 		.is_supported = test__tsc_is_supported,
 	},
+	{
+		.desc = "Sigtrap support",
+		.func = test__sigtrap,
+		.is_supported = test__wp_is_supported, /* uses wp for test */
+	},
 	{
 		.func = NULL,
 	},
diff --git a/tools/perf/tests/sigtrap.c b/tools/perf/tests/sigtrap.c
new file mode 100644
index 000000000000..c367cc2f64d5
--- /dev/null
+++ b/tools/perf/tests/sigtrap.c
@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Basic test for sigtrap support.
+ *
+ * Copyright (C) 2021, Google LLC.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <linux/hw_breakpoint.h>
+#include <pthread.h>
+#include <signal.h>
+#include <sys/ioctl.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#include "cloexec.h"
+#include "debug.h"
+#include "event.h"
+#include "tests.h"
+#include "../perf-sys.h"
+
+#define NUM_THREADS 5
+
+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;
+
+#define TEST_SIG_DATA (~(uint64_t)(&ctx.iterate_on))
+
+static struct perf_event_attr make_event_attr(void)
+{
+	struct perf_event_attr attr = {
+		.type		= PERF_TYPE_BREAKPOINT,
+		.size		= sizeof(attr),
+		.sample_period	= 1,
+		.disabled	= 1,
+		.bp_addr	= (unsigned long)&ctx.iterate_on,
+		.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,
+	};
+	return attr;
+}
+
+static void
+sigtrap_handler(int signum __maybe_unused, siginfo_t *info, void *ucontext __maybe_unused)
+{
+	if (!__atomic_fetch_add(&ctx.signal_count, 1, __ATOMIC_RELAXED))
+		ctx.first_siginfo = *info;
+	__atomic_fetch_sub(&ctx.tids_want_signal, syscall(SYS_gettid), __ATOMIC_RELAXED);
+}
+
+static void *test_thread(void *arg)
+{
+	pthread_barrier_t *barrier = (pthread_barrier_t *)arg;
+	pid_t tid = syscall(SYS_gettid);
+	int i;
+
+	pthread_barrier_wait(barrier);
+
+	__atomic_fetch_add(&ctx.tids_want_signal, tid, __ATOMIC_RELAXED);
+	for (i = 0; i < ctx.iterate_on - 1; i++)
+		__atomic_fetch_add(&ctx.tids_want_signal, tid, __ATOMIC_RELAXED);
+
+	return NULL;
+}
+
+static int run_test_threads(pthread_t *threads, pthread_barrier_t *barrier)
+{
+	int i;
+
+	pthread_barrier_wait(barrier);
+	for (i = 0; i < NUM_THREADS; i++)
+		TEST_ASSERT_EQUAL("pthread_join() failed", pthread_join(threads[i], NULL), 0);
+
+	return TEST_OK;
+}
+
+static int run_stress_test(int fd, pthread_t *threads, pthread_barrier_t *barrier)
+{
+	int ret;
+
+	ctx.iterate_on = 3000;
+
+	TEST_ASSERT_EQUAL("misfired signal?", ctx.signal_count, 0);
+	TEST_ASSERT_EQUAL("enable failed", ioctl(fd, PERF_EVENT_IOC_ENABLE, 0), 0);
+	ret = run_test_threads(threads, barrier);
+	TEST_ASSERT_EQUAL("disable failed", ioctl(fd, PERF_EVENT_IOC_DISABLE, 0), 0);
+
+	TEST_ASSERT_EQUAL("unexpected sigtraps", ctx.signal_count, NUM_THREADS * ctx.iterate_on);
+	TEST_ASSERT_EQUAL("missing signals or incorrectly delivered", ctx.tids_want_signal, 0);
+	TEST_ASSERT_VAL("unexpected si_addr", ctx.first_siginfo.si_addr == &ctx.iterate_on);
+	TEST_ASSERT_EQUAL("unexpected si_errno", ctx.first_siginfo.si_errno, PERF_TYPE_BREAKPOINT);
+#if 0 /* FIXME: test build and enable when libc's signal.h has si_perf. */
+	TEST_ASSERT_VAL("unexpected si_perf", ctx.first_siginfo.si_perf == TEST_SIG_DATA);
+#endif
+
+	return ret;
+}
+
+int test__sigtrap(struct test *test __maybe_unused, int subtest __maybe_unused)
+{
+	struct perf_event_attr attr = make_event_attr();
+	struct sigaction action = {};
+	struct sigaction oldact;
+	pthread_t threads[NUM_THREADS];
+	pthread_barrier_t barrier;
+	int i, fd, ret = TEST_FAIL;
+
+	pthread_barrier_init(&barrier, NULL, NUM_THREADS + 1);
+
+	action.sa_flags = SA_SIGINFO | SA_NODEFER;
+	action.sa_sigaction = sigtrap_handler;
+	sigemptyset(&action.sa_mask);
+	if (sigaction(SIGTRAP, &action, &oldact)) {
+		pr_debug("FAILED sigaction()\n");
+		goto out;
+	}
+
+	fd = sys_perf_event_open(&attr, 0, -1, -1, perf_event_open_cloexec_flag());
+	if (fd < 0) {
+		pr_debug("FAILED sys_perf_event_open()\n");
+		goto out_restore_sigaction;
+	}
+
+	for (i = 0; i < NUM_THREADS; i++) {
+		if (pthread_create(&threads[i], NULL, test_thread, &barrier)) {
+			pr_debug("FAILED pthread_create()");
+			goto out_close_perf_event;
+		}
+	}
+
+	ret = run_stress_test(fd, threads, &barrier);
+
+out_close_perf_event:
+	close(fd);
+out_restore_sigaction:
+	sigaction(SIGTRAP, &oldact, NULL);
+out:
+	pthread_barrier_destroy(&barrier);
+	return ret;
+}
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index b85f005308a3..c3f2e2ecbfd6 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -127,6 +127,7 @@ int test__parse_metric(struct test *test, int subtest);
 int test__pe_file_parsing(struct test *test, int subtest);
 int test__expand_cgroup_events(struct test *test, int subtest);
 int test__perf_time_to_tsc(struct test *test, int subtest);
+int test__sigtrap(struct test *test, int subtest);
 
 bool test__bp_signal_is_supported(void);
 bool test__bp_account_is_supported(void);
-- 
2.31.0.208.g409f899ff0-goog


  parent reply	other threads:[~2021-04-08 10:37 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-08 10:35 [PATCH v4 00/10] Add support for synchronous signals on perf events Marco Elver
2021-04-08 10:35 ` [PATCH v4 01/10] perf: Rework perf_event_exit_event() Marco Elver
2021-04-16 15:01   ` [tip: perf/core] " tip-bot2 for Peter Zijlstra
2021-04-08 10:35 ` [PATCH v4 02/10] perf: Apply PERF_EVENT_IOC_MODIFY_ATTRIBUTES to children Marco Elver
2021-04-16 15:01   ` [tip: perf/core] " tip-bot2 for Marco Elver
2021-04-08 10:35 ` [PATCH v4 03/10] perf: Support only inheriting events if cloned with CLONE_THREAD Marco Elver
2021-04-08 10:35 ` [PATCH v4 04/10] perf: Add support for event removal on exec Marco Elver
2021-04-16 15:01   ` [tip: perf/core] " tip-bot2 for Marco Elver
2021-04-08 10:36 ` [PATCH v4 05/10] signal: Introduce TRAP_PERF si_code and si_perf to siginfo Marco Elver
2021-04-16 15:01   ` [tip: perf/core] " tip-bot2 for Marco Elver
     [not found]   ` <CGME20210420212618eucas1p102b427d1af9c682217dfe093f3eac3e8@eucas1p1.samsung.com>
2021-04-20 21:26     ` [PATCH v4 05/10] " Marek Szyprowski
2021-04-20 22:42       ` Marco Elver
2021-04-21  6:21         ` Marek Szyprowski
2021-04-21  7:35           ` Marek Szyprowski
2021-04-21  8:11             ` Marco Elver
2021-04-21  9:35               ` Marek Szyprowski
2021-04-21 10:57                 ` Marek Szyprowski
2021-04-21 11:03                   ` Marco Elver
2021-04-21 13:19                     ` Marek Szyprowski
2021-04-21 15:11                       ` Marco Elver
2021-04-21 16:27                         ` Marco Elver
2021-04-21 18:23                           ` Marco Elver
2021-04-22  6:12                             ` Marek Szyprowski
2021-04-22  6:47                               ` Marco Elver
2021-04-22  8:16                                 ` Jon Hunter
2021-04-26  7:35                                 ` Alexander Egorenkov
2021-04-21 15:07   ` Jon Hunter
2021-04-08 10:36 ` [PATCH v4 06/10] perf: Add support for SIGTRAP on perf events Marco Elver
2021-04-08 10:36 ` [PATCH v4 07/10] selftests/perf_events: Add kselftest for process-wide sigtrap handling Marco Elver
2021-04-16 15:01   ` [tip: perf/core] " tip-bot2 for Marco Elver
2021-04-08 10:36 ` [PATCH v4 08/10] selftests/perf_events: Add kselftest for remove_on_exec Marco Elver
2021-04-16 15:01   ` [tip: perf/core] " tip-bot2 for Marco Elver
2021-04-08 10:36 ` [PATCH v4 09/10] tools headers uapi: Sync tools/include/uapi/linux/perf_event.h Marco Elver
2021-04-08 10:36 ` Marco Elver [this message]
2021-04-14  8:37 ` [PATCH v4 00/10] Add support for synchronous signals on perf events Peter Zijlstra

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