log: Open log file CLOEXEC so child processes don't get the fd

Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Bryce Harrington <bryce@osg.samsung.com>
Signed-off-by: Derek Foreman <derekf@osg.samsung.com>

shared/os-compatibility.c

@@ -36,8 +36,8 @@
 
 #include "os-compatibility.h"
 
-static int
+int
-set_cloexec_or_close(int fd)
+os_fd_set_cloexec(int fd)
 {
 	long flags;
 
@@ -46,17 +46,23 @@ set_cloexec_or_close(int fd)
 
 	flags = fcntl(fd, F_GETFD);
 	if (flags == -1)
-		goto err;
+		return -1;
 
 	if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) == -1)
-		goto err;
+		return -1;
 
-	return fd;
+	return 0;
+}
 
-err:
+static int
+set_cloexec_or_close(int fd)
+{
+	if (os_fd_set_cloexec(fd) != 0) {
 		close(fd);
 		return -1;
 	}
+	return fd;
+}
 
 int
 os_socketpair_cloexec(int domain, int type, int protocol, int *sv)

shared/os-compatibility.h

@@ -40,6 +40,9 @@ backtrace(void **buffer, int size)
 }
 #endif
 
+int
+os_fd_set_cloexec(int fd);
+
 int
 os_socketpair_cloexec(int domain, int type, int protocol, int *sv);
 

src/log.c

@@ -36,6 +36,8 @@
 
 #include "compositor.h"
 
+#include "os-compatibility.h"
+
 static FILE *weston_logfile = NULL;
 
 static int cached_tm_mday = -1;
@@ -77,8 +79,11 @@ weston_log_file_open(const char *filename)
 {
 	wl_log_set_handler_server(custom_handler);
 
-	if (filename != NULL)
+	if (filename != NULL) {
 		weston_logfile = fopen(filename, "a");
+		if (weston_logfile)
+			os_fd_set_cloexec(fileno(weston_logfile));
+	}
 
 	if (weston_logfile == NULL)
 		weston_logfile = stderr;