On Wed, Mar 2, 2022 at 4:00 PM Nathan Chancellor <nathan@xxxxxxxxxx> wrote:
>
> 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: 943e6a8beeac ("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@xxxxxxxxx>
> Suggested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Thanks for the patch!
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> ---
> drivers/gpu/drm/selftests/test-drm_plane_helper.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> 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,
>
> base-commit: 9ae2ac4d31a85ce59cc560d514a31b95f4ace154
> --
> 2.35.1
>
--
Thanks,
~Nick Desaulniers
