lib: Show stacktrace when terminated by runner

The igt_runner sends a SIGTERM to ask the test to cleanly exit upon an
external timeout. It is useful to know what the code was doing when the
timeout occurred, just in case it was unexpectedly stuck. However, since
we use SIGTERM internally to marshal helper processes, we want to keep
SIGTERM quiet, and so opt to use SIGQUIT for the timeout request
instead.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Petri Latvala <petri.latvala@intel.com>
Reviewed-by: Petri Latvala <petri.latvala@intel.com>

2 files changed, 25 insertions, 10 deletions

diff --git a/lib/igt_core.c b/lib/igt_core.c
index e0989f53..64883d64 100644
--- a/lib/igt_core.c
+++ b/lib/igt_core.c
@@ -1852,14 +1852,29 @@ static struct {
 
 static igt_exit_handler_t exit_handler_fn[MAX_EXIT_HANDLERS];
 static bool exit_handler_disabled;
+static const struct {
+	int number;
+	const char *name;
+	size_t name_len;
+} handled_signals[] = {
 #define SIGDEF(x) { x, #x, sizeof(#x) - 1 }
 #define SILENT(x) { x, NULL, 0 }
-static const struct { int number; const char *name; size_t name_len; } handled_signals[] =
-	{ SILENT(SIGINT), SILENT(SIGHUP), SILENT(SIGTERM), SILENT(SIGQUIT),
-	  SILENT(SIGPIPE), SIGDEF(SIGABRT), SIGDEF(SIGSEGV), SIGDEF(SIGBUS),
-	  SIGDEF(SIGFPE) };
+
+	SILENT(SIGINT),
+	SILENT(SIGHUP),
+	SILENT(SIGPIPE),
+	SILENT(SIGTERM),
+
+	SIGDEF(SIGQUIT), /* used by igt_runner for its external timeout */
+
+	SIGDEF(SIGABRT),
+	SIGDEF(SIGSEGV),
+	SIGDEF(SIGBUS),
+	SIGDEF(SIGFPE)
+
 #undef SILENT
 #undef SIGDEF
+};
 
 static int install_sig_handler(int sig_num, sighandler_t handler)
 {
@@ -1940,15 +1955,15 @@ static void fatal_sig_handler(int sig)
 			__write_stderr(handled_signals[i].name,
 				       handled_signals[i].name_len);
 			write_stderr(".\n");
+
+			print_backtrace_sig_safe();
 		}
 
 		if (crash_signal(sig)) {
 			/* Linux standard to return exit code as 128 + signal */
 			if (!failed_one)
 				igt_exitcode = 128 + sig;
-
 			failed_one = true;
-			print_backtrace_sig_safe();
 
 			if (in_subtest)
 				exit_subtest("CRASH");
diff --git a/runner/executor.c b/runner/executor.c
index a7d1f5f8..54c530b7 100644
--- a/runner/executor.c
+++ b/runner/executor.c
@@ -510,11 +510,11 @@ static int monitor_output(pid_t child,
 			switch (killed) {
 			case 0:
 				if (settings->log_level >= LOG_LEVEL_NORMAL) {
-					printf("Timeout. Killing the current test with SIGTERM.\n");
+					printf("Timeout. Killing the current test with SIGQUIT.\n");
 					fflush(stdout);
 				}
 
-				killed = SIGTERM;
+				killed = SIGQUIT;
 				if (!kill_child(killed, child))
 					return -1;
 
@@ -526,7 +526,7 @@ static int monitor_output(pid_t child,
 				watchdogs_set_timeout(120);
 				intervals_left = timeout_intervals = 1;
 				break;
-			case SIGTERM:
+			case SIGQUIT:
 				if (settings->log_level >= LOG_LEVEL_NORMAL) {
 					printf("Timeout. Killing the current test with SIGKILL.\n");
 					fflush(stdout);
@@ -706,7 +706,7 @@ static int monitor_output(pid_t child,
 
 				aborting = true;
 				timeout = 2;
-				killed = SIGTERM;
+				killed = SIGQUIT;
 				if (!kill_child(killed, child))
 					return -1;