| Message ID | 20221109001424.1422495-1-nathan@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] drm: xlnx: Fix return type of zynqmp_dp_bridge_mode_valid | expand |
Hi Nathan, Thank you for the patch. On Tue, Nov 08, 2022 at 05:14:25PM -0700, Nathan Chancellor wrote: > From: Nathan Huckleberry <nhuck@google.com> > > The mode_valid field in drm_bridge_helper_funcs is expected to be of > type > enum drm_mode_status (* mode_valid) (struct drm_bridge *bridge, > struct drm_display_mode *mode); > > The mismatched return type breaks forward edge kCFI since the underlying > function definition does not match the function hook definition. A new > warning in clang will catch this at compile time: > > drivers/gpu/drm/xlnx/zynqmp_dp.c:1573:16: 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 = zynqmp_dp_bridge_mode_valid, > ^~~~~~~~~~~~~~~~~~~~~~~~~~~ > 1 error generated. > > The return type of zynqmp_dp_bridge_mode_valid should be changed from > int to enum drm_mode_status. > > Reported-by: Dan Carpenter <error27@gmail.com> > Link: https://github.com/ClangBuiltLinux/linux/issues/1703 > Link: https://github.com/ClangBuiltLinux/linux/issues/1750 > Signed-off-by: Nathan Huckleberry <nhuck@google.com> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > [nathan: Rebase on drm-misc-next and fix conflicts > Add note about new clang warning] > Signed-off-by: Nathan Chancellor <nathan@kernel.org> > --- > > Please consider picking this up so that it makes 6.2. I'll send a pull request shortly. > v2: > - Take over for Nathan, as he is busy with other matters. > - Rebase on drm-misc-next and resolve conflicts. > - Add a note about new clang warning that will catch this issue at > compile time. > > v1: https://lore.kernel.org/20220913205600.155172-1-nhuck@google.com/ > > drivers/gpu/drm/xlnx/zynqmp_dp.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c > index 7c9ae167eac7..0a7b466446fb 100644 > --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c > +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c > @@ -1362,9 +1362,10 @@ static void zynqmp_dp_bridge_detach(struct drm_bridge *bridge) > zynqmp_dp_aux_cleanup(dp); > } > > -static int zynqmp_dp_bridge_mode_valid(struct drm_bridge *bridge, > - const struct drm_display_info *info, > - const struct drm_display_mode *mode) > +static enum drm_mode_status > +zynqmp_dp_bridge_mode_valid(struct drm_bridge *bridge, > + const struct drm_display_info *info, > + const struct drm_display_mode *mode) > { > struct zynqmp_dp *dp = bridge_to_dp(bridge); > int rate; > > base-commit: 1a0257c352638916fdaffaac2ddedb8e049312f3
On Tue, Nov 08, 2022 at 05:14:25PM -0700, Nathan Chancellor wrote: > From: Nathan Huckleberry <nhuck@google.com> > > The mode_valid field in drm_bridge_helper_funcs is expected to be of > type > enum drm_mode_status (* mode_valid) (struct drm_bridge *bridge, > struct drm_display_mode *mode); > > The mismatched return type breaks forward edge kCFI since the underlying > function definition does not match the function hook definition. A new > warning in clang will catch this at compile time: > > drivers/gpu/drm/xlnx/zynqmp_dp.c:1573:16: 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 = zynqmp_dp_bridge_mode_valid, > ^~~~~~~~~~~~~~~~~~~~~~~~~~~ > 1 error generated. > > The return type of zynqmp_dp_bridge_mode_valid should be changed from > int to enum drm_mode_status. > > Reported-by: Dan Carpenter <error27@gmail.com> > Link: https://github.com/ClangBuiltLinux/linux/issues/1703 > Link: https://github.com/ClangBuiltLinux/linux/issues/1750 > Signed-off-by: Nathan Huckleberry <nhuck@google.com> Reviewed-by: Kees Cook <keescook@chromium.org>
diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c index 7c9ae167eac7..0a7b466446fb 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c @@ -1362,9 +1362,10 @@ static void zynqmp_dp_bridge_detach(struct drm_bridge *bridge) zynqmp_dp_aux_cleanup(dp); } -static int zynqmp_dp_bridge_mode_valid(struct drm_bridge *bridge, - const struct drm_display_info *info, - const struct drm_display_mode *mode) +static enum drm_mode_status +zynqmp_dp_bridge_mode_valid(struct drm_bridge *bridge, + const struct drm_display_info *info, + const struct drm_display_mode *mode) { struct zynqmp_dp *dp = bridge_to_dp(bridge); int rate;