-Wframe-larger-than in drivers/gpu/drm/selftests/test-drm_plane_helper.c

[nathanchance]

Initially reported by the kernel test robot: https://lore.kernel.org/r/202112211210.kJg5QWU6-lkp@intel.com/

On at least ARCH=hexagon allmodconfig but likely other 32-bit architectures:

drivers/gpu/drm/selftests/test-drm_plane_helper.c:76:5: error: stack frame size (1136) exceeds limit (1024) in 'igt_check_plane_state' [-Werror,-Wframe-larger-than]
int igt_check_plane_state(void *ignored)
    ^
1 error generated.

Introduced by https://cgit.freedesktop.org/drm/drm-misc/commit/?id=943e6a8beeac1b676265f2dd81a69d7bede5e41d; all of the structures in this function are on the stack.

[nickdesaulniers]

I wonder if these could be made function static?

[nathanchance]

I think so? It appears that igt_check_plane_state() is only called once, so there should be no problem with static storage.

diff --git a/drivers/gpu/drm/selftests/test-drm_plane_helper.c b/drivers/gpu/drm/selftests/test-drm_plane_helper.c
index ceebeede55ea..b61273e9c403 100644
--- a/drivers/gpu/drm/selftests/test-drm_plane_helper.c
+++ b/drivers/gpu/drm/selftests/test-drm_plane_helper.c
@@ -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,

[nathanchance]

Patch submitted: https://lore.kernel.org/r/20220302235909.784935-1-nathan@kernel.org/

[nathanchance]

Patch accepted: https://cgit.freedesktop.org/drm-misc/commit/?id=a860f266a0e19f271b839451d291a6acf6ddcfe8

[nathanchance]

Merged into mainline: https://git.kernel.org/linus/a860f266a0e19f271b839451d291a6acf6ddcfe8