With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG),
indirect call targets are validated against the expected function
pointer prototype to make sure the call target is valid to help mitigate
ROP attacks. If they are not identical, there is a failure at run time,
which manifests as either a kernel panic or thread getting killed. A
proposed warning in clang aims to catch these at compile time, which
reveals:
drivers/gpu/drm/meson/meson_encoder_cvbs.c:211:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' with an expression of type 'int (struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict]
.mode_valid = meson_encoder_cvbs_mode_valid,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
->mode_valid() in 'struct drm_bridge_funcs' expects a return type of
'enum drm_mode_status', not 'int'. Adjust the return type of
meson_encoder_cvbs_mode_valid() to match the prototype's to resolve the
warning and CFI failure.
Link: https://github.com/ClangBuiltLinux/linux/issues/1750
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221102155242.1927166-1-nathan@kernel.org
of_graph_get_remote_node() returns remote device nodepointer with
refcount incremented, we should use of_node_put() on it when done.
Add missing of_node_put() to avoid refcount leak.
Fixes: 318ba02cd8 ("drm/meson: encoder_cvbs: switch to bridge with ATTACH_NO_CONNECTOR")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220601033927.47814-2-linmq006@gmail.com
Drop the local connector and move all callback to bridge funcs in order
to leverage the generic CVBS display connector.
This will also permit adding custom cvbs connectors for ADC based HPD
detection on some Amlogic SoC based boards.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
[narmstrong: fixed diplay typo in commit log]
Link: https://patchwork.freedesktop.org/patch/msgid/20211020123947.2585572-7-narmstrong@baylibre.com
