Use O_CLOEXEC when creating FDs

This is needed so that new processes (created with fork+exec) don't
inherit open files, which can be important for a number of reasons.

Since O_CLOEXEC is relatively new (POSIX.1-2008, before that Linux
specific), we #define it to 0 in io.h to prevent compilation errors on
older/crappy systems. At least this is the plan.

input.c creates a pipe. For that, add a mp_set_cloexec() function (which
is based on Weston's code in vo_wayland.c, but more correct). We could
use pipe2() instead, but that is Linux specific. Technically, we have a
race condition, but it won't matter.

1 files changed, 3 insertions, 1 deletions

diff --git a/mpvcore/player/command.c b/mpvcore/player/command.c
index d8a317413f..129c0aa58a 100644
--- a/mpvcore/player/command.c
+++ b/mpvcore/player/command.c
@@ -65,6 +65,8 @@
 #include <sys/mman.h>
 #endif
 
+#include "osdep/io.h"
+
 #include "mp_core.h"
 #include "mp_lua.h"
 
@@ -2334,7 +2336,7 @@ static int overlay_add(struct MPContext *mpctx, int id, int x, int y,
             fd = -1;
         close_fd = false;
     } else {
-        fd = open(file, O_RDONLY | O_BINARY);
+        fd = open(file, O_RDONLY | O_BINARY | O_CLOEXEC);
     }
     void *p = mmap(NULL, h * stride, PROT_READ, MAP_SHARED, fd, offset);
     if (fd >= 0 && close_fd)