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, 11 insertions, 6 deletions

diff --git a/mpvcore/input/input.c b/mpvcore/input/input.c
index 3e0313976a..744d474919 100644
--- a/mpvcore/input/input.c
+++ b/mpvcore/input/input.c
@@ -2309,12 +2309,17 @@ struct input_ctx *mp_input_init(struct mpv_global *global)
     }
 
 #ifndef __MINGW32__
-    long ret = pipe(ictx->wakeup_pipe);
-    for (int i = 0; i < 2 && ret >= 0; i++) {
-        ret = fcntl(ictx->wakeup_pipe[i], F_GETFL);
-        if (ret < 0)
-            break;
-        ret = fcntl(ictx->wakeup_pipe[i], F_SETFL, ret | O_NONBLOCK);
+    int ret = pipe(ictx->wakeup_pipe);
+    if (ret == 0) {
+        for (int i = 0; i < 2 && ret >= 0; i++) {
+            mp_set_cloexec(ictx->wakeup_pipe[i]);
+            ret = fcntl(ictx->wakeup_pipe[i], F_GETFL);
+            if (ret < 0)
+                break;
+            ret = fcntl(ictx->wakeup_pipe[i], F_SETFL, ret | O_NONBLOCK);
+            if (ret < 0)
+                break;
+        }
     }
     if (ret < 0)
         MP_ERR(ictx, "Failed to initialize wakeup pipe: %s\n", strerror(errno));