Hi, Nathan: Nathan Chancellor <[email protected]> 於 2025年11月25日週二 下午10:14寫道： > > When building with -Wincompatible-function-pointer-types-strict, a > warning designed to catch kernel control flow integrity (kCFI) issues at > build time, there is an instance in the new HDMI v2 drm/mediatek code: > > drivers/gpu/drm/mediatek/mtk_hdmi_v2.c:1331:31: error: incompatible > function pointer types initializing 'enum drm_mode_status (*)(const struct > drm_bridge *, const struct drm_display_mode *, unsigned long long)' with an > expression of type 'int (const struct drm_bridge *, const struct > drm_display_mode *, unsigned long long)' > [-Werror,-Wincompatible-function-pointer-types-strict] > 1331 | .hdmi_tmds_char_rate_valid = > mtk_hdmi_v2_hdmi_tmds_char_rate_valid, > | > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > While 'int' and 'enum drm_mode_status' are ABI compatible, hence no > regular warning from -Wincompatible-function-pointer-types, the mismatch > will trigger a kCFI violation when mtk_hdmi_v2_tmds_char_rate_valid() is > called indirectly. > > Update the return type of mtk_hdmi_v2_tmds_char_rate_valid() to be 'enum > drm_mode_status' to clear up the warning and kCFI violation.
Applied to mediatek-drm-fixes [1], thanks. [1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-fixes Regards, Chun-Kuang. > > Fixes: 8d0f79886273 ("drm/mediatek: Introduce HDMI/DDC v2 for MT8195/MT8188") > Signed-off-by: Nathan Chancellor <[email protected]> > --- > drivers/gpu/drm/mediatek/mtk_hdmi_v2.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi_v2.c > b/drivers/gpu/drm/mediatek/mtk_hdmi_v2.c > index c272e1e74b7d..454b8b93b834 100644 > --- a/drivers/gpu/drm/mediatek/mtk_hdmi_v2.c > +++ b/drivers/gpu/drm/mediatek/mtk_hdmi_v2.c > @@ -1120,9 +1120,10 @@ static void mtk_hdmi_v2_hpd_disable(struct drm_bridge > *bridge) > mtk_hdmi_v2_disable(hdmi); > } > > -static int mtk_hdmi_v2_hdmi_tmds_char_rate_valid(const struct drm_bridge > *bridge, > - const struct > drm_display_mode *mode, > - unsigned long long tmds_rate) > +static enum drm_mode_status > +mtk_hdmi_v2_hdmi_tmds_char_rate_valid(const struct drm_bridge *bridge, > + const struct drm_display_mode *mode, > + unsigned long long tmds_rate) > { > if (mode->clock < MTK_HDMI_V2_CLOCK_MIN) > return MODE_CLOCK_LOW; > > --- > base-commit: a846505a193d7492ad3531e33cacfca31e4bcdd1 > change-id: 20251125-drm-mediatek-hdmi-v2-wifpts-d67b55175609 > > Best regards, > -- > Nathan Chancellor <[email protected]> >
