tests/gbm: Add gbm_device_get_fd() test

Make sure that GBM doesn't dup() the FD from under us, as users rely on
this being the case.

Part-of: <https://gitlab.freedesktop.org/mesa/piglit/-/merge_requests/865>

2 files changed, 54 insertions, 0 deletions

diff --git a/tests/gbm/CMakeLists.no_api.txt b/tests/gbm/CMakeLists.no_api.txt
index c1fd99c66..57c750d2e 100644
--- a/tests/gbm/CMakeLists.no_api.txt
+++ b/tests/gbm/CMakeLists.no_api.txt
@@ -11,4 +11,8 @@ if(PIGLIT_HAS_GBM_BO_GET_FD_FOR_PLANE AND LIBDRM_FOUND)
    piglit_add_executable(gbm-multi-plane gbm-multi-plane.c)
 endif()
 
+if(PIGLIT_HAS_GBM)
+   piglit_add_executable(gbm-device gbm-device.c)
+endif()
+
 # vim: ft=cmake:
diff --git a/tests/gbm/gbm-device.c b/tests/gbm/gbm-device.c
new file mode 100644
index 000000000..8e1a82fde
--- /dev/null
+++ b/tests/gbm/gbm-device.c
@@ -0,0 +1,50 @@
+/* Copyright (c) 2024 Collabora Ltd
+ * SPDX-License-Identifier: MIT
+ */
+
+/**
+ * \file
+ * \brief Tests for libgbm.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <gbm.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "piglit-util.h"
+
+int
+main(int argc, char **argv)
+{
+	int drm_fd;
+	char *nodename;
+	struct gbm_device *gbm;
+
+	/* Strip common piglit args. */
+	piglit_strip_arg(&argc, argv, "-fbo");
+	piglit_strip_arg(&argc, argv, "-auto");
+
+	nodename = getenv("WAFFLE_GBM_DEVICE");
+	if (!nodename)
+		nodename = "/dev/dri/renderD128";
+	drm_fd = open(nodename, O_RDWR);
+	if (drm_fd == -1) {
+		perror("Error opening render node");
+		piglit_report_result(PIGLIT_SKIP);
+	}
+
+	gbm = gbm_create_device(drm_fd);
+	if (!gbm)
+		piglit_report_result(PIGLIT_FAIL);
+
+	if (gbm_device_get_fd(gbm) != drm_fd)
+		piglit_report_result(PIGLIT_FAIL);
+
+	gbm_device_destroy(gbm);
+	close(drm_fd);
+
+	piglit_report_result(PIGLIT_PASS);
+}