lib/core: Handle asserts in threads

Since IGT is using magic control blocks (igt_subtest et al.) asserts
jump out the them using longjmp() causing a bunch of confusing messages
and occasionally crashing the whole process.

This is not the behavior we want :-)

With this patch:

1. simple_main, dynamic and subtest each clears the thread failure state
   at the start

2. each of those blocks also asserts no thread failures at the end

3. igt_assert() in non-main thread prints out the error + stacktrace
   and marks that we have failed thread

Issue: https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/issues/55
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Petri Latvala <petri.latvala@intel.com>

6 files changed, 263 insertions, 0 deletions

diff --git a/lib/igt_core.c b/lib/igt_core.c
index c95295c74..ccf06cf44 100644
--- a/lib/igt_core.c
+++ b/lib/igt_core.c
@@ -1272,6 +1272,7 @@ bool __igt_run_subtest(const char *subtest_name, const char *file, const int lin
 		fprintf(stderr, "Starting subtest: %s\n", subtest_name);
 
 	_igt_log_buffer_reset();
+	igt_thread_clear_fail_state();
 
 	igt_gettime(&subtest_time);
 	return (in_subtest = subtest_name);
@@ -1302,6 +1303,7 @@ bool __igt_run_dynamic_subtest(const char *dynamic_subtest_name)
 		fprintf(stderr, "Starting dynamic subtest: %s\n", dynamic_subtest_name);
 
 	_igt_log_buffer_reset();
+	igt_thread_clear_fail_state();
 
 	_igt_dynamic_tests_executed++;
 
@@ -1510,6 +1512,8 @@ void __igt_skip_check(const char *file, const int line,
  */
 void igt_success(void)
 {
+	igt_thread_assert_no_failures();
+
 	if (in_subtest && !in_dynamic_subtest && _igt_dynamic_tests_executed >= 0) {
 		/*
 		 * We're exiting a dynamic container, yield a result
@@ -1549,6 +1553,11 @@ void igt_fail(int exitcode)
 {
 	assert(exitcode != IGT_EXIT_SUCCESS && exitcode != IGT_EXIT_SKIP);
 
+	if (!igt_thread_is_main()) {
+		igt_thread_fail();
+		pthread_exit(NULL);
+	}
+
 	igt_debug_wait_for_keypress("failure");
 
 	/* Exit immediately if the test is already exiting and igt_fail is
@@ -2049,6 +2058,9 @@ void igt_exit(void)
 {
 	int tmp;
 
+	if (!test_with_subtests)
+		igt_thread_assert_no_failures();
+
 	igt_exit_called = true;
 
 	if (igt_key_file)
diff --git a/lib/igt_thread.c b/lib/igt_thread.c
index deab62257..5bdda4102 100644
--- a/lib/igt_thread.c
+++ b/lib/igt_thread.c
@@ -22,12 +22,42 @@
  */
 
 #include <pthread.h>
+#include <stdlib.h>
+#include <stdatomic.h>
 
 #include "igt_core.h"
 #include "igt_thread.h"
 
 static pthread_key_t __igt_is_main_thread;
 
+static _Atomic(bool) __thread_failed = false;
+
+void igt_thread_clear_fail_state(void)
+{
+	assert(igt_thread_is_main());
+
+	__thread_failed = false;
+}
+
+void igt_thread_fail(void)
+{
+	assert(!igt_thread_is_main());
+
+	__thread_failed = true;
+}
+
+void igt_thread_assert_no_failures(void)
+{
+	assert(igt_thread_is_main());
+
+	if (__thread_failed) {
+		/* so we won't get stuck in a loop */
+		igt_thread_clear_fail_state();
+		igt_critical("Failure in a thread!\n");
+		igt_fail(IGT_EXIT_FAILURE);
+	}
+}
+
 bool igt_thread_is_main(void)
 {
 	return pthread_getspecific(__igt_is_main_thread) != NULL;
diff --git a/lib/igt_thread.h b/lib/igt_thread.h
index b16f803f0..4b9c222d1 100644
--- a/lib/igt_thread.h
+++ b/lib/igt_thread.h
@@ -21,4 +21,8 @@
  * IN THE SOFTWARE.
  */
 
+void igt_thread_clear_fail_state(void);
+void igt_thread_fail(void);
+void igt_thread_assert_no_failures(void);
+
 bool igt_thread_is_main(void);
diff --git a/lib/tests/igt_tests_common.h b/lib/tests/igt_tests_common.h
index fa8ad9201..058f6265c 100644
--- a/lib/tests/igt_tests_common.h
+++ b/lib/tests/igt_tests_common.h
@@ -30,6 +30,7 @@
 #include <errno.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <regex.h>
 
 /*
  * We need to hide assert from the cocci igt test refactor spatch.
@@ -161,4 +162,25 @@ static inline void read_whole_pipe(int fd, char *buf, size_t buflen)
 		offset += readlen;
 	}
 }
+
+static inline bool matches(char *str, const char *regex)
+{
+	int ret;
+	regex_t reg;
+
+	ret = regcomp(&reg, regex, REG_EXTENDED | REG_NEWLINE);
+
+	if (ret == 0)
+		ret = regexec(&reg, str, 0, NULL, 0);
+
+	if (0 != ret && REG_NOMATCH != ret) {
+		char err[256];
+		regerror(ret, &reg, err, sizeof(err));
+		printf("%s\n", err);
+		abort();
+	}
+
+	regfree(&reg);
+	return !ret;
+}
 #endif
diff --git a/lib/tests/igt_thread.c b/lib/tests/igt_thread.c
new file mode 100644
index 000000000..7185dd5d1
--- /dev/null
+++ b/lib/tests/igt_thread.c
@@ -0,0 +1,194 @@
+/*
+ * Copyright © 2020 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <pthread.h>
+
+#include "drmtest.h"
+#include "igt_core.h"
+#include "igt_tests_common.h"
+
+char prog[] = "igt_thread";
+char *fake_argv[] = { prog };
+int fake_argc = ARRAY_SIZE(fake_argv);
+
+static void *success_thread(void *data)
+{
+	return NULL;
+}
+
+static void *failure_thread(void *data)
+{
+	igt_assert(false);
+	return NULL;
+}
+
+static void one_subtest_fail(void) {
+	igt_subtest_init(fake_argc, fake_argv);
+
+	igt_subtest("subtest-a") {
+		pthread_t thread;
+		pthread_create(&thread, 0, failure_thread, NULL);
+		pthread_join(thread, NULL);
+	}
+
+	igt_subtest("subtest-b") {
+		pthread_t thread;
+		pthread_create(&thread, 0, success_thread, NULL);
+		pthread_join(thread, NULL);
+	}
+
+	igt_exit();
+}
+
+static void one_dynamic_fail(void) {
+	igt_subtest_init(fake_argc, fake_argv);
+
+	igt_subtest_with_dynamic("dynamic-container") {
+		igt_dynamic("dynamic-a") {
+			pthread_t thread;
+			pthread_create(&thread, 0, failure_thread, NULL);
+			pthread_join(thread, NULL);
+		}
+
+		igt_dynamic("dynamic-b") {
+			pthread_t thread;
+			pthread_create(&thread, 0, success_thread, NULL);
+			pthread_join(thread, NULL);
+		}
+	}
+
+	igt_exit();
+}
+
+static void simple_success(void) {
+	pthread_t thread;
+
+	igt_simple_init(fake_argc, fake_argv);
+
+	pthread_create(&thread, 0, success_thread, NULL);
+	pthread_join(thread, NULL);
+
+	igt_exit();
+}
+
+static void simple_failure(void) {
+	pthread_t thread;
+
+	igt_simple_init(fake_argc, fake_argv);
+
+	pthread_create(&thread, 0, failure_thread, NULL);
+	pthread_join(thread, NULL);
+
+	igt_exit();
+}
+
+int main(int argc, char **argv)
+{
+	int status;
+	int outfd;
+	pid_t pid;
+
+	/* failing should be limited just to a single subtest */ {
+		static char out[4096];
+
+		pid = do_fork_bg_with_pipes(one_subtest_fail, &outfd, NULL);
+
+		read_whole_pipe(outfd, out, sizeof(out));
+
+		internal_assert(safe_wait(pid, &status) != -1);
+		internal_assert_wexited(status, IGT_EXIT_FAILURE);
+
+		internal_assert(matches(out, "\\[thread:.*\\] Stack trace"));
+		internal_assert(strstr(out, "Subtest subtest-a: FAIL"));
+		internal_assert(strstr(out, "Subtest subtest-b: SUCCESS"));
+
+		close(outfd);
+	}
+
+	/* failing should be limited just to a dynamic subsubtest */ {
+		static char out[4096];
+
+		pid = do_fork_bg_with_pipes(one_dynamic_fail, &outfd, NULL);
+
+		read_whole_pipe(outfd, out, sizeof(out));
+
+		internal_assert(safe_wait(pid, &status) != -1);
+		internal_assert_wexited(status, IGT_EXIT_FAILURE);
+
+		internal_assert(matches(out, "\\[thread:.*\\] Stack trace"));
+		internal_assert(strstr(out, "Dynamic subtest dynamic-a: FAIL"));
+		internal_assert(strstr(out, "Dynamic subtest dynamic-b: SUCCESS"));
+
+		close(outfd);
+	}
+
+	/* success in a simple test */ {
+		static char out[4096];
+
+		pid = do_fork_bg_with_pipes(simple_success, &outfd, NULL);
+
+		read_whole_pipe(outfd, out, sizeof(out));
+
+		internal_assert(safe_wait(pid, &status) != -1);
+		internal_assert_wexited(status, IGT_EXIT_SUCCESS);
+
+
+		internal_assert(matches(out, "^SUCCESS"));
+
+		close(outfd);
+	}
+
+	/* success in a simple test */ {
+		static char out[4096];
+
+		pid = do_fork_bg_with_pipes(simple_success, &outfd, NULL);
+
+		read_whole_pipe(outfd, out, sizeof(out));
+
+		internal_assert(safe_wait(pid, &status) != -1);
+		internal_assert_wexited(status, IGT_EXIT_SUCCESS);
+
+		internal_assert(matches(out, "^SUCCESS"));
+
+		close(outfd);
+	}
+
+	/* failure in a simple test */ {
+		static char out[4096];
+
+		pid = do_fork_bg_with_pipes(simple_failure, &outfd, NULL);
+
+		read_whole_pipe(outfd, out, sizeof(out));
+
+		internal_assert(safe_wait(pid, &status) != -1);
+		internal_assert_wexited(status, IGT_EXIT_FAILURE);
+
+		internal_assert(matches(out, "\\[thread:.*\\] Stack trace"));
+		internal_assert(matches(out, "^FAIL"));
+
+		close(outfd);
+	}
+
+	return 0;
+}
diff --git a/lib/tests/meson.build b/lib/tests/meson.build
index 47ef303af..9cf5ff479 100644
--- a/lib/tests/meson.build
+++ b/lib/tests/meson.build
@@ -18,6 +18,7 @@ lib_tests = [
 	'igt_simulation',
 	'igt_stats',
 	'igt_subtest_group',
+	'igt_thread',
 	'i915_perf_data_alignment',
 ]