From: Maria Matejka <mq@ucw.cz>
Date: Fri, 4 Oct 2019 10:20:02 +0000 (+0200)
Subject: Fixed undefined behavior on signals.
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e3c5cf66371eff4f4bc686c337da2f2494734d01;p=thirdparty%2Fbird.git

Fixed undefined behavior on signals.

The C11 specification allows only sig_atomic_t and _Atomic variable
access. All other accesses to global variables are undefined behavior.

Using int was probably OK on x86 and x86_64; yet there were some reports
from other architectures (especially some MIPS) that in rare cases,
after issuing SIGHUP, BIRD did strange things.
---

diff --git a/sysdep/unix/io.c b/sysdep/unix/io.c
index 8f76652ad..d2f1f205b 100644
--- a/sysdep/unix/io.c
+++ b/sysdep/unix/io.c
@@ -2144,10 +2144,6 @@ watchdog_stop(void)
  *	Main I/O Loop
  */
 
-volatile int async_config_flag;		/* Asynchronous reconfiguration/dump scheduled */
-volatile int async_dump_flag;
-volatile int async_shutdown_flag;
-
 void
 io_init(void)
 {
diff --git a/sysdep/unix/main.c b/sysdep/unix/main.c
index a898a19a8..0624e7b37 100644
--- a/sysdep/unix/main.c
+++ b/sysdep/unix/main.c
@@ -583,9 +583,9 @@ cmd_graceful_restart(void)
  *	Signals
  */
 
-volatile int async_config_flag;
-volatile int async_dump_flag;
-volatile int async_shutdown_flag;
+volatile sig_atomic_t async_config_flag;
+volatile sig_atomic_t async_dump_flag;
+volatile sig_atomic_t async_shutdown_flag;
 
 static void
 handle_sighup(int sig UNUSED)
diff --git a/sysdep/unix/unix.h b/sysdep/unix/unix.h
index 7e3a9fede..1490243cb 100644
--- a/sysdep/unix/unix.h
+++ b/sysdep/unix/unix.h
@@ -10,6 +10,7 @@
 #define _BIRD_UNIX_H_
 
 #include <sys/socket.h>
+#include <signal.h>
 
 struct pool;
 struct iface;
@@ -96,9 +97,9 @@ int sockaddr_read(sockaddr *sa, int af, ip_addr *a, struct iface **ifa, uint *po
 #define SUN_LEN(ptr) ((size_t) (((struct sockaddr_un *) 0)->sun_path) + strlen ((ptr)->sun_path))
 #endif
 
-extern volatile int async_config_flag;
-extern volatile int async_dump_flag;
-extern volatile int async_shutdown_flag;
+extern volatile sig_atomic_t async_config_flag;
+extern volatile sig_atomic_t async_dump_flag;
+extern volatile sig_atomic_t async_shutdown_flag;
 
 void io_init(void);
 void io_loop(void);
diff --git a/test/birdtest.c b/test/birdtest.c
index 823b02ff6..ede4eb527 100644
--- a/test/birdtest.c
+++ b/test/birdtest.c
@@ -35,6 +35,11 @@ static int no_fork;
 static int no_timeout;
 static int is_terminal;		/* Whether stdout is a live terminal or pipe redirect */
 
+volatile sig_atomic_t async_config_flag;		/* Asynchronous reconfiguration/dump scheduled */
+volatile sig_atomic_t async_dump_flag;
+volatile sig_atomic_t async_shutdown_flag;
+
+
 uint bt_verbose;
 const char *bt_filename;
 const char *bt_test_id;