| Message ID | 20230412142923.136707-1-mcanal@igalia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/gem: Check for valid formats | expand |
On Wed, Apr 12, 2023 at 11:29:23AM -0300, Maíra Canal wrote: > Currently, drm_gem_fb_create() doesn't check if the pixel format is > supported, which can lead to the acceptance of invalid pixel formats > e.g. the acceptance of invalid modifiers. Therefore, add a check for > valid formats on drm_gem_fb_create(). > > Moreover, note that this check is only valid for atomic drivers, > because, for non-atomic drivers, checking drm_any_plane_has_format() is > not possible since the format list for the primary plane is fake, and > we'd therefor reject valid formats. > > Adding this check to drm_gem_fb_create() will guarantee that the > igt@kms_addfb_basic@addfb25-bad-modifier IGT test passes for drivers > using this callback. > > Signed-off-by: Maíra Canal <mcanal@igalia.com> Seems sane enough, assuming all the drivers using this are happy with the baked in !modifiers -> linear assumption. That might be a good thing to highlight in the docs. Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> BTW long ago I tried to make igt check this stugg a bit more vehemently: https://patchwork.freedesktop.org/patch/239814/?series=46876&rev=1 Someone might want to pick that up again and see if it cab be makde to work with more drivers than just i915. > --- > > This patch is a recapture of a series I sent a while ago. Initially, I sent a > patch [1] similar to this one in which I introduced the format check to > drm_gem_fb_create(). > > Based on the feedback on the patch, I placed the check inside > framebuffer_check() [2] so that it wouldn't be needed to hit any driver-specific > code path when the check fails. Therefore, we could remove the check from the > specific drivers (i915, amdgpu, and vmwgfx). > > But, with some new feedback, it was shown that introducing this check inside > framebuffer_check() is problematic for the i915 driver [3]. So, I kept the check > inside the i915 driver and removed the check from amdgpu and vmwgfx [4]. But, > this yet hasn't solved the i915 problem [5]. > > As we cannot add the check inside framebuffer_check() without affecting the i915 > behavior, I propose going back to the original patch. This way we can guarantee > a more uniform behavior from the drivers that use the drm_gem_fb_create() > callback. > > [1] https://lore.kernel.org/dri-devel/20230103125322.855089-1-mcanal@igalia.com/T/ > [2] https://lore.kernel.org/dri-devel/20230109105807.18172-1-mcanal@igalia.com/T/ > [3] https://lore.kernel.org/dri-devel/Y8AAdW2y7zN7DCUZ@intel.com/ > [4] https://lore.kernel.org/dri-devel/20230113112743.188486-1-mcanal@igalia.com/T/ > [5] https://lore.kernel.org/dri-devel/Y8FXWvEhO7GCRKVJ@intel.com/ > > Best Regards, > - Maíra Canal > > --- > Documentation/gpu/todo.rst | 7 ++----- > drivers/gpu/drm/drm_gem_framebuffer_helper.c | 9 +++++++++ > 2 files changed, 11 insertions(+), 5 deletions(-) > > diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst > index 1f8a5ebe188e..68bdafa0284f 100644 > --- a/Documentation/gpu/todo.rst > +++ b/Documentation/gpu/todo.rst > @@ -276,11 +276,8 @@ Various hold-ups: > - Need to switch to drm_fbdev_generic_setup(), otherwise a lot of the custom fb > setup code can't be deleted. > > -- Many drivers wrap drm_gem_fb_create() only to check for valid formats. For > - atomic drivers we could check for valid formats by calling > - drm_plane_check_pixel_format() against all planes, and pass if any plane > - supports the format. For non-atomic that's not possible since like the format > - list for the primary plane is fake and we'd therefor reject valid formats. > +- Need to switch to drm_gem_fb_create(), as now drm_gem_fb_create() checks for > + valid formats for atomic drivers. > > - Many drivers subclass drm_framebuffer, we'd need a embedding compatible > version of the varios drm_gem_fb_create functions. Maybe called > diff --git a/drivers/gpu/drm/drm_gem_framebuffer_helper.c b/drivers/gpu/drm/drm_gem_framebuffer_helper.c > index e93533b86037..b8a615a138cd 100644 > --- a/drivers/gpu/drm/drm_gem_framebuffer_helper.c > +++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c > @@ -9,6 +9,7 @@ > #include <linux/module.h> > > #include <drm/drm_damage_helper.h> > +#include <drm/drm_drv.h> > #include <drm/drm_fourcc.h> > #include <drm/drm_framebuffer.h> > #include <drm/drm_gem.h> > @@ -164,6 +165,14 @@ int drm_gem_fb_init_with_funcs(struct drm_device *dev, > return -EINVAL; > } > > + if (drm_drv_uses_atomic_modeset(dev) && > + !drm_any_plane_has_format(dev, mode_cmd->pixel_format, > + mode_cmd->modifier[0])) { > + drm_dbg(dev, "Unsupported pixel format %p4cc / modifier 0x%llx\n", > + &mode_cmd->pixel_format, mode_cmd->modifier[0]); > + return -EINVAL; > + } > + > for (i = 0; i < info->num_planes; i++) { > unsigned int width = mode_cmd->width / (i ? info->hsub : 1); > unsigned int height = mode_cmd->height / (i ? info->vsub : 1); > -- > 2.39.2
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index 1f8a5ebe188e..68bdafa0284f 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -276,11 +276,8 @@ Various hold-ups: - Need to switch to drm_fbdev_generic_setup(), otherwise a lot of the custom fb setup code can't be deleted. -- Many drivers wrap drm_gem_fb_create() only to check for valid formats. For - atomic drivers we could check for valid formats by calling - drm_plane_check_pixel_format() against all planes, and pass if any plane - supports the format. For non-atomic that's not possible since like the format - list for the primary plane is fake and we'd therefor reject valid formats. +- Need to switch to drm_gem_fb_create(), as now drm_gem_fb_create() checks for + valid formats for atomic drivers. - Many drivers subclass drm_framebuffer, we'd need a embedding compatible version of the varios drm_gem_fb_create functions. Maybe called diff --git a/drivers/gpu/drm/drm_gem_framebuffer_helper.c b/drivers/gpu/drm/drm_gem_framebuffer_helper.c index e93533b86037..b8a615a138cd 100644 --- a/drivers/gpu/drm/drm_gem_framebuffer_helper.c +++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c @@ -9,6 +9,7 @@ #include <linux/module.h> #include <drm/drm_damage_helper.h> +#include <drm/drm_drv.h> #include <drm/drm_fourcc.h> #include <drm/drm_framebuffer.h> #include <drm/drm_gem.h> @@ -164,6 +165,14 @@ int drm_gem_fb_init_with_funcs(struct drm_device *dev, return -EINVAL; } + if (drm_drv_uses_atomic_modeset(dev) && + !drm_any_plane_has_format(dev, mode_cmd->pixel_format, + mode_cmd->modifier[0])) { + drm_dbg(dev, "Unsupported pixel format %p4cc / modifier 0x%llx\n", + &mode_cmd->pixel_format, mode_cmd->modifier[0]); + return -EINVAL; + } + for (i = 0; i < info->num_planes; i++) { unsigned int width = mode_cmd->width / (i ? info->hsub : 1); unsigned int height = mode_cmd->height / (i ? info->vsub : 1);
Currently, drm_gem_fb_create() doesn't check if the pixel format is supported, which can lead to the acceptance of invalid pixel formats e.g. the acceptance of invalid modifiers. Therefore, add a check for valid formats on drm_gem_fb_create(). Moreover, note that this check is only valid for atomic drivers, because, for non-atomic drivers, checking drm_any_plane_has_format() is not possible since the format list for the primary plane is fake, and we'd therefor reject valid formats. Adding this check to drm_gem_fb_create() will guarantee that the igt@kms_addfb_basic@addfb25-bad-modifier IGT test passes for drivers using this callback. Signed-off-by: Maíra Canal <mcanal@igalia.com> --- This patch is a recapture of a series I sent a while ago. Initially, I sent a patch [1] similar to this one in which I introduced the format check to drm_gem_fb_create(). Based on the feedback on the patch, I placed the check inside framebuffer_check() [2] so that it wouldn't be needed to hit any driver-specific code path when the check fails. Therefore, we could remove the check from the specific drivers (i915, amdgpu, and vmwgfx). But, with some new feedback, it was shown that introducing this check inside framebuffer_check() is problematic for the i915 driver [3]. So, I kept the check inside the i915 driver and removed the check from amdgpu and vmwgfx [4]. But, this yet hasn't solved the i915 problem [5]. As we cannot add the check inside framebuffer_check() without affecting the i915 behavior, I propose going back to the original patch. This way we can guarantee a more uniform behavior from the drivers that use the drm_gem_fb_create() callback. [1] https://lore.kernel.org/dri-devel/20230103125322.855089-1-mcanal@igalia.com/T/ [2] https://lore.kernel.org/dri-devel/20230109105807.18172-1-mcanal@igalia.com/T/ [3] https://lore.kernel.org/dri-devel/Y8AAdW2y7zN7DCUZ@intel.com/ [4] https://lore.kernel.org/dri-devel/20230113112743.188486-1-mcanal@igalia.com/T/ [5] https://lore.kernel.org/dri-devel/Y8FXWvEhO7GCRKVJ@intel.com/ Best Regards, - Maíra Canal --- Documentation/gpu/todo.rst | 7 ++----- drivers/gpu/drm/drm_gem_framebuffer_helper.c | 9 +++++++++ 2 files changed, 11 insertions(+), 5 deletions(-)