Unverified Commit a860f266 authored Mar 02, 2022 by Nathan Chancellor Committed by Maxime Ripard Mar 21, 2022

drm/selftest: plane_helper: Put test structures in static storage

Clang warns on certain 32-bit architectures:

  drivers/gpu/drm/selftests/test-drm_plane_helper.c:76:5: warning: stack frame size (1064) exceeds limit (1024) in 'igt_check_plane_state' [-Wframe-larger-than]
  int igt_check_plane_state(void *ignored)
      ^
  1 warning generated.

The structures in igt_check_plane_state() total 1008 bytes, so any small
amount of inlining will cause the stack frame to exceed the 32-bit limit
of 1024, triggering the warning.

Move these structures to static storage, which dramatically reduces the
amount of stack space in igt_check_plane_state(). There is no testing
impact, as igt_check_plane_state() is only called once in the driver.

Fixes: 943e6a8b ("mock a drm_plane in igt_check_plane_state to make the test more robust")
Link: https://github.com/ClangBuiltLinux/linux/issues/1600


Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220302235909.784935-1-nathan@kernel.org

parent 1d204ee1

drivers/gpu/drm/selftests/test-drm_plane_helper.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -77,7 +77,7 @@ int igt_check_plane_state(void *ignored)
		{
		int ret;

		const struct drm_crtc_state crtc_state = {
		static const struct drm_crtc_state crtc_state = {
		.crtc = ZERO_SIZE_PTR,
		.enable = true,
		.active = true,
		@@ -87,14 +87,14 @@ int igt_check_plane_state(void *ignored)
		DRM_MODE_FLAG_NHSYNC \| DRM_MODE_FLAG_NVSYNC)
		},
		};
		struct drm_plane plane = {
		static struct drm_plane plane = {
		.dev = NULL
		};
		struct drm_framebuffer fb = {
		static struct drm_framebuffer fb = {
		.width = 2048,
		.height = 2048
		};
		struct drm_plane_state plane_state = {
		static struct drm_plane_state plane_state = {
		.plane = &plane,
		.crtc = ZERO_SIZE_PTR,
		.fb = &fb,