From: Nathan Chancellor nathan@kernel.org
commit 0c09bc33aa8e9dc867300acaadc318c2f0d85a1e upstream.
When booting a kernel compiled with clang's CFI protection (CONFIG_CFI_CLANG), there is a CFI failure in drm_simple_kms_crtc_mode_valid() when trying to call simpledrm_simple_display_pipe_mode_valid() through ->mode_valid():
[ 0.322802] CFI failure (target: simpledrm_simple_display_pipe_mode_valid+0x0/0x8): ... [ 0.324928] Call trace: [ 0.324969] __ubsan_handle_cfi_check_fail+0x58/0x60 [ 0.325053] __cfi_check_fail+0x3c/0x44 [ 0.325120] __cfi_slowpath_diag+0x178/0x200 [ 0.325192] drm_simple_kms_crtc_mode_valid+0x58/0x80 [ 0.325279] __drm_helper_update_and_validate+0x31c/0x464 ...
The ->mode_valid() member in 'struct drm_simple_display_pipe_funcs' expects a return type of 'enum drm_mode_status', not 'int'. Correct it to fix the CFI failure.
Cc: stable@vger.kernel.org Fixes: 11e8f5fd223b ("drm: Add simpledrm driver") Link: https://github.com/ClangBuiltLinux/linux/issues/1647 Reported-by: Tomasz Paweł Gajc tpgxyz@gmail.com Signed-off-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Thomas Zimmermann tzimmermann@suse.de Reviewed-by: Sami Tolvanen samitolvanen@google.com Link: https://patchwork.freedesktop.org/patch/msgid/20220725233629.223223-1-nathan... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/tiny/simpledrm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/gpu/drm/tiny/simpledrm.c +++ b/drivers/gpu/drm/tiny/simpledrm.c @@ -627,7 +627,7 @@ static const struct drm_connector_funcs .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, };
-static int +static enum drm_mode_status simpledrm_simple_display_pipe_mode_valid(struct drm_simple_display_pipe *pipe, const struct drm_display_mode *mode) {