From 87bd718de54ced41544e88200418bc091a1fce50 Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Tue, 15 Dec 2020 20:52:53 +0100
Subject: [PATCH] backend: use fcntl(F_DUPFD_CLOEXEC) instead of dup

This makes sure the CLOEXEC flag is set on the dup'ed FD.
---
 backend/headless/backend.c | 13 +++++++------
 backend/wayland/backend.c  |  6 ++++--
 backend/x11/backend.c      | 10 +++++-----
 3 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/backend/headless/backend.c b/backend/headless/backend.c
index 3995d1eb..c6c2d0f9 100644
--- a/backend/headless/backend.c
+++ b/backend/headless/backend.c
@@ -1,6 +1,7 @@
 #define _POSIX_C_SOURCE 200809L
 #include <assert.h>
 #include <drm_fourcc.h>
+#include <fcntl.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <wlr/interfaces/wlr_input_device.h>
@@ -113,19 +114,19 @@ static bool backend_init(struct wlr_headless_backend *backend,
 	backend->renderer = renderer;
 	backend->egl = wlr_gles2_renderer_get_egl(renderer);
 
-	int fd = wlr_renderer_get_drm_fd(renderer);
-	if (fd < 0) {
+	int drm_fd = wlr_renderer_get_drm_fd(renderer);
+	if (drm_fd < 0) {
 		wlr_log(WLR_ERROR, "Failed to get DRM device FD from renderer");
 		return false;
 	}
 
-	fd = dup(fd);
-	if (fd < 0) {
-		wlr_log_errno(WLR_ERROR, "dup failed");
+	drm_fd = fcntl(drm_fd, F_DUPFD_CLOEXEC, 0);
+	if (drm_fd < 0) {
+		wlr_log_errno(WLR_ERROR, "fcntl(F_DUPFD_CLOEXEC) failed");
 		return false;
 	}
 
-	struct wlr_gbm_allocator *alloc = wlr_gbm_allocator_create(fd);
+	struct wlr_gbm_allocator *alloc = wlr_gbm_allocator_create(drm_fd);
 	if (alloc == NULL) {
 		wlr_log(WLR_ERROR, "Failed to create GBM allocator");
 		return false;
diff --git a/backend/wayland/backend.c b/backend/wayland/backend.c
index 14b6ca6c..5b8bce9b 100644
--- a/backend/wayland/backend.c
+++ b/backend/wayland/backend.c
@@ -1,4 +1,6 @@
+#define _POSIX_C_SOURCE 200809L
 #include <assert.h>
+#include <fcntl.h>
 #include <limits.h>
 #include <stdint.h>
 #include <stdlib.h>
@@ -335,9 +337,9 @@ struct wlr_backend *wlr_wl_backend_create(struct wl_display *display,
 		goto error_event;
 	}
 
-	drm_fd = dup(drm_fd);
+	drm_fd = fcntl(drm_fd, F_DUPFD_CLOEXEC, 0);
 	if (drm_fd < 0) {
-		wlr_log_errno(WLR_ERROR, "dup failed");
+		wlr_log_errno(WLR_ERROR, "fcntl(F_DUPFD_CLOEXEC) failed");
 		goto error_event;
 	}
 
diff --git a/backend/x11/backend.c b/backend/x11/backend.c
index 9482f86d..48f1aaee 100644
--- a/backend/x11/backend.c
+++ b/backend/x11/backend.c
@@ -1,6 +1,6 @@
-#define _POSIX_C_SOURCE 200112L
-
+#define _POSIX_C_SOURCE 200809L
 #include <assert.h>
+#include <fcntl.h>
 #include <limits.h>
 #include <stdbool.h>
 #include <stdio.h>
@@ -490,9 +490,9 @@ struct wlr_backend *wlr_x11_backend_create(struct wl_display *display,
 		return false;
 	}
 
-	drm_fd = dup(drm_fd);
-	if (fd < 0) {
-		wlr_log_errno(WLR_ERROR, "dup failed");
+	drm_fd = fcntl(drm_fd, F_DUPFD_CLOEXEC, 0);
+	if (drm_fd < 0) {
+		wlr_log_errno(WLR_ERROR, "fcntl(F_DUPFD_CLOEXEC) failed");
 		return false;
 	}