utils: add lxc_set_death_signal()

src/lxc/start.c

@@ -996,32 +996,6 @@ void lxc_abort(const char *name, struct lxc_handler *handler)
 	}
 }
 
-static int lxc_set_death_signal(int signal)
-{
-	int ret;
-	pid_t ppid;
-
-	ret = prctl(PR_SET_PDEATHSIG, signal, 0, 0, 0);
-
-	/* Check whether we have been orphaned. */
-	ppid = (pid_t)syscall(SYS_getppid);
-	if (ppid == 1) {
-		pid_t self;
-
-		self = lxc_raw_getpid();
-		ret = kill(self, SIGKILL);
-		if (ret < 0)
-			return -1;
-	}
-
-	if (ret < 0) {
-		SYSERROR("Failed to set PR_SET_PDEATHSIG to %d", signal);
-		return -1;
-	}
-
-	return 0;
-}
-
 static int do_start(void *data)
 {
 	int ret;

src/lxc/utils.c

@@ -2510,3 +2510,29 @@ uint64_t lxc_find_next_power2(uint64_t n)
 	n = n << 1;
 	return n;
 }
+
+int lxc_set_death_signal(int signal)
+{
+	int ret;
+	pid_t ppid;
+
+	ret = prctl(PR_SET_PDEATHSIG, signal, 0, 0, 0);
+
+	/* Check whether we have been orphaned. */
+	ppid = (pid_t)syscall(SYS_getppid);
+	if (ppid == 1) {
+		pid_t self;
+
+		self = lxc_raw_getpid();
+		ret = kill(self, SIGKILL);
+		if (ret < 0)
+			return -1;
+	}
+
+	if (ret < 0) {
+		SYSERROR("Failed to set PR_SET_PDEATHSIG to %d", signal);
+		return -1;
+	}
+
+	return 0;
+}

src/lxc/utils.h

@@ -589,4 +589,7 @@ static inline pid_t lxc_raw_gettid(void)
 #endif
 }
 
+/* Set a signal the child process will receive after the parent has died. */
+extern int lxc_set_death_signal(int signal);
+
 #endif /* __LXC_UTILS_H */