The patch below does not apply to the 6.0-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

Possible dependencies:

f9929f69de94 ("drm/simpledrm: Fix return type of simpledrm_simple_display_pipe_mode_valid()")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From f9929f69de94212f98b3ad72a3e81c3bd3d333e0 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor nathan@kernel.org Date: Mon, 25 Jul 2022 16:36:29 -0700 Subject: [PATCH] drm/simpledrm: Fix return type of simpledrm_simple_display_pipe_mode_valid() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

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... (cherry picked from commit 0c09bc33aa8e9dc867300acaadc318c2f0d85a1e) Signed-off-by: Thomas Zimmermann tzimmermann@suse.de

diff --git a/drivers/gpu/drm/tiny/simpledrm.c b/drivers/gpu/drm/tiny/simpledrm.c index 768242a78e2b..5422363690e7 100644 --- a/drivers/gpu/drm/tiny/simpledrm.c +++ b/drivers/gpu/drm/tiny/simpledrm.c @@ -627,7 +627,7 @@ static const struct drm_connector_funcs simpledrm_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) {