s4: torture: Ensure kernel oplock test can't hang in pause().

Use an alarm to break out of waiting for a signal.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13121

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>

Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Thu Nov 16 22:27:06 CET 2017 on sn-devel-144

1 files changed, 67 insertions, 0 deletions

diff --git a/source4/torture/smb2/oplock.c b/source4/torture/smb2/oplock.c
index 1830a017e83..b6d9f842336 100644
--- a/source4/torture/smb2/oplock.c
+++ b/source4/torture/smb2/oplock.c
@@ -4817,6 +4817,17 @@ static void got_rt_break(int sig)
 	got_break = 1;
 }
 
+static int got_alarm;
+
+/*
+ * Signal handler.
+ */
+
+static void got_alarm_fn(int sig)
+{
+	got_alarm = 1;
+}
+
 /*
  * Child process function.
  */
@@ -4835,6 +4846,13 @@ static int do_child_process(int pipefd, const char *name)
 	if (ret == -1) {
 		return 1;
 	}
+	/* Set up a signal handler for SIGALRM. */
+	ZERO_STRUCT(act);
+	act.sa_handler = got_alarm_fn;
+	ret = sigaction(SIGALRM, &act, NULL);
+	if (ret == -1) {
+		return 1;
+	}
 	/* Open the passed in file and get a kernel oplock. */
 	fd = open(name, O_RDWR, 0666);
 	if (fd == -1) {
@@ -4857,16 +4875,26 @@ static int do_child_process(int pipefd, const char *name)
 		return 5;
 	}
 
+	/* Ensure the pause doesn't hang forever. */
+	alarm(5);
+
 	/* Wait for RT_SIGNAL_LEASE. */
 	ret = pause();
 	if (ret != -1 || errno != EINTR) {
 		return 6;
 	}
 
+	if (got_alarm == 1) {
+		return 10;
+	}
+
 	if (got_break != 1) {
 		return 7;
 	}
 
+	/* Cancel any pending alarm. */
+	alarm(0);
+
 	/* Force the server to wait for 3 seconds. */
 	sleep(3);
 
@@ -4928,6 +4956,23 @@ static bool wait_for_child_oplock(struct torture_context *tctx,
 }
 #endif
 
+static void child_sig_term_handler(struct tevent_context *ev,
+				struct tevent_signal *se,
+				int signum,
+				int count,
+				void *siginfo,
+				void *private_data)
+{
+	int *pstatus = (int *)private_data;
+	int status;
+	wait(&status);
+	if (WIFEXITED(status)) {
+		*pstatus = WEXITSTATUS(status);
+	} else {
+		*pstatus = status;
+	}
+}
+
 /*
  * Deal with a non-smbd process holding a kernel oplock.
  */
@@ -4944,6 +4989,8 @@ static bool test_smb2_kernel_oplocks8(struct torture_context *tctx,
 	struct smb2_handle h1 = {{0}};
 	struct smb2_handle h2 = {{0}};
 	const char *localdir = torture_setting_string(tctx, "localdir", NULL);
+	struct tevent_signal *se = NULL;
+	int child_exit_code = -1;
 	time_t start;
 	time_t end;
 
@@ -4963,6 +5010,14 @@ static bool test_smb2_kernel_oplocks8(struct torture_context *tctx,
 	smb2_util_close(tree, h1);
 	ZERO_STRUCT(h1);
 
+	se = tevent_add_signal(tctx->ev,
+				tctx,
+				SIGCHLD,
+				0,
+				child_sig_term_handler,
+				&child_exit_code);
+	torture_assert(tctx, se != NULL, "tevent_add_signal failed\n");
+
 	/* Take the oplock locally in a sub-process. */
 	ret = wait_for_child_oplock(tctx, localdir, fname);
 	torture_assert_goto(tctx, ret = true, ret, done,
@@ -5013,6 +5068,18 @@ static bool test_smb2_kernel_oplocks8(struct torture_context *tctx,
 			"Error opening the file\n");
 	h2 = io.out.file.handle;
 
+	/* Wait for the exit code from the child. */
+	while (child_exit_code == -1) {
+		int rval = tevent_loop_once(tctx->ev);
+		torture_assert(tctx, rval == 0, "tevent_loop_once error\n");
+	}
+
+	if (child_exit_code != 0) {
+		torture_comment(tctx, "Bad child exit code %d\n",
+			child_exit_code);
+		ret = false;
+	}
+
 done:
 	if (!smb2_util_handle_empty(h1)) {
 		smb2_util_close(tree, h1);