[igt-dev] [PATCH i-g-t] lib: Show stacktrace when terminated by runner

[Chris Wilson]

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 at chris-wilson.co.uk>
Cc: Petri Latvala <petri.latvala at intel.com>
---
 lib/igt_core.c    | 27 +++++++++++++++++++++------
 runner/executor.c |  8 ++++----
 2 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/lib/igt_core.c b/lib/igt_core.c
index e0989f538..64883d640 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 4a0a1219a..4b5e01fdb 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;
 
-- 
2.20.0.rc1