[lxc-devel] [PATCH] lxc_init.c: error handing for sigaction and sigprocmask

[Qiang Huang]

Look through all LXC code and seems like only here are missed.

Signed-off-by: Qiang Huang <h.huangqiang at huawei.com>
---
Maybe this bug can be marked resolved:
https://github.com/lxc/lxc/issues/83
---
 src/lxc/lxc_init.c | 46 +++++++++++++++++++++++++++++++---------------
 1 file changed, 31 insertions(+), 15 deletions(-)

diff --git a/src/lxc/lxc_init.c b/src/lxc/lxc_init.c
index d88a935..a59dd9c 100644
--- a/src/lxc/lxc_init.c
+++ b/src/lxc/lxc_init.c
@@ -123,11 +123,14 @@ int main(int argc, char *argv[])
 	 * mask all the signals so we are safe to install a
 	 * signal handler and to fork
 	 */
-	sigfillset(&mask);
-	sigdelset(&mask, SIGILL);
-	sigdelset(&mask, SIGSEGV);
-	sigdelset(&mask, SIGBUS);
-	sigprocmask(SIG_SETMASK, &mask, &omask);
+	if (sigfillset(&mask) ||
+	    sigdelset(&mask, SIGILL) ||
+	    sigdelset(&mask, SIGSEGV) ||
+	    sigdelset(&mask, SIGBUS) ||
+	    sigprocmask(SIG_SETMASK, &mask, &omask)) {
+		SYSERROR("failed to set signal mask");
+		exit(EXIT_FAILURE);
+	}

 	for (i = 1; i < NSIG; i++) {
 		struct sigaction act;
@@ -143,15 +146,22 @@ int main(int argc, char *argv[])
 		    i == SIGKILL)
 			continue;

-		sigfillset(&act.sa_mask);
-		sigdelset(&act.sa_mask, SIGILL);
-		sigdelset(&act.sa_mask, SIGSEGV);
-		sigdelset(&act.sa_mask, SIGBUS);
-		sigdelset(&act.sa_mask, SIGSTOP);
-		sigdelset(&act.sa_mask, SIGKILL);
+		if (sigfillset(&act.sa_mask) ||
+		    sigdelset(&act.sa_mask, SIGILL) ||
+		    sigdelset(&act.sa_mask, SIGSEGV) ||
+		    sigdelset(&act.sa_mask, SIGBUS) ||
+		    sigdelset(&act.sa_mask, SIGSTOP) ||
+		    sigdelset(&act.sa_mask, SIGKILL)) {
+			ERROR("failed to set signal");
+			exit(EXIT_FAILURE);
+		}
+
 		act.sa_flags = 0;
 		act.sa_handler = interrupt_handler;
-		sigaction(i, &act, NULL);
+		if (sigaction(i, &act, NULL)) {
+			SYSERROR("failed to sigaction");
+			exit(EXIT_FAILURE);
+		}
 	}

 	lxc_setup_fs();
@@ -170,7 +180,10 @@ int main(int argc, char *argv[])
 		for (i = 1; i < NSIG; i++)
 			signal(i, SIG_DFL);

-		sigprocmask(SIG_SETMASK, &omask, NULL);
+		if (sigprocmask(SIG_SETMASK, &omask, NULL)) {
+			SYSERROR("failed to set signal mask");
+			exit(EXIT_FAILURE);
+		}

 		NOTICE("about to exec '%s'", aargv[0]);

@@ -180,8 +193,11 @@ int main(int argc, char *argv[])
 	}

 	/* let's process the signals now */
-	sigdelset(&omask, SIGALRM);
-	sigprocmask(SIG_SETMASK, &omask, NULL);
+	if (sigdelset(&omask, SIGALRM) ||
+	    sigprocmask(SIG_SETMASK, &omask, NULL)) {
+		SYSERROR("failed to set signal mask");
+		exit(EXIT_FAILURE);
+	}

 	/* no need of other inherited fds but stderr */
 	close(fileno(stdin));
-- 
1.8.3