tests/gem_suspend: test debugfs/sysfs reads while s/r

Just a very quick hack cobbled together with /bin/sh and exec. We
can't use system since that does stupid things with singals ... Still
we need to whack the child process pretty hard to get rid of it.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

lib/drmtest.c

@@ -1080,7 +1080,8 @@ void igt_stop_helper(struct igt_helper_process *proc)
 
 	assert(proc->running);
 
-	assert(kill(proc->pid, SIGQUIT) == 0);
+	assert(kill(proc->pid,
+		    proc->use_SIGKILL ? SIGKILL : SIGQUIT) == 0);
 	while (waitpid(proc->pid, &status, 0) == -1 &&
 	       errno == -EINTR)
 		;

lib/drmtest.h

@@ -243,6 +243,7 @@ void igt_waitchildren(void);
 
 struct igt_helper_process {
 	bool running;
+	bool use_SIGKILL;
 	pid_t pid;
 	int id;
 };

tests/gem_suspend.c

@@ -95,6 +95,56 @@ test_fence_restore(int fd, bool tiled2untiled)
 	munmap(ptr_tiled, OBJECT_SIZE);
 }
 
+static void
+test_debugfs_reader(void)
+{
+	struct igt_helper_process reader = {};
+	reader.use_SIGKILL = true;
+
+	igt_fork_helper(&reader) {
+		static const char dfs_base[] = "/sys/kernel/debug/dri";
+		static char tmp[1024];
+
+		snprintf(tmp, sizeof(tmp) - 1,
+			 "while true; do find %s/%i/ -type f | xargs cat &> /dev/null; done",
+			 dfs_base, drm_get_card());
+		assert(execl("/bin/sh", "sh", "-c", tmp, (char *) NULL) != -1);
+	}
+
+	sleep(1);
+
+	igt_system_suspend_autoresume();
+
+	sleep(1);
+
+	igt_stop_helper(&reader);
+}
+
+static void
+test_sysfs_reader(void)
+{
+	struct igt_helper_process reader = {};
+	reader.use_SIGKILL = true;
+
+	igt_fork_helper(&reader) {
+		static const char dfs_base[] = "/sys/class/drm/card";
+		static char tmp[1024];
+
+		snprintf(tmp, sizeof(tmp) - 1,
+			 "while true; do find %s%i*/ -type f | xargs cat &> /dev/null; done",
+			 dfs_base, drm_get_card());
+		assert(execl("/bin/sh", "sh", "-c", tmp, (char *) NULL) != -1);
+	}
+
+	sleep(1);
+
+	igt_system_suspend_autoresume();
+
+	sleep(1);
+
+	igt_stop_helper(&reader);
+}
+
 int fd;
 
 int main(int argc, char **argv)
@@ -110,6 +160,12 @@ int main(int argc, char **argv)
 	igt_subtest("fence-restore-untiled")
 		test_fence_restore(fd, false);
 
+	igt_subtest("debugfs-reader")
+		test_debugfs_reader();
+
+	igt_subtest("sysfs-reader")
+		test_sysfs_reader();
+
 	igt_fixture
 		close(fd);