drm/i915/fbdev: fixup setting screen_size

Since we are actually mapping the object and not the vma, when dealing
with LMEM, we should be careful and use the backing store size here,
since the vma->node.size could have all kinds of funny padding
constraints, which could result in us writing to OOB address.

v2(Chris):
  - Prefer vma->size here, which should be the backing store size. Some
    more rework is needed here to stop using node.size in some other
    places.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220304095934.925036-1-matthew.auld@intel.com
This commit is contained in:
Matthew Auld 2022-03-04 09:59:33 +00:00
parent eb95081921
commit 892bfb8a60

View file

@ -279,7 +279,7 @@ static int intelfb_create(struct drm_fb_helper *helper,
/* Our framebuffer is the entirety of fbdev's system memory */
info->fix.smem_start =
(unsigned long)(ggtt->gmadr.start + vma->node.start);
info->fix.smem_len = vma->node.size;
info->fix.smem_len = vma->size;
}
vaddr = i915_vma_pin_iomap(vma);
@ -290,7 +290,7 @@ static int intelfb_create(struct drm_fb_helper *helper,
goto out_unpin;
}
info->screen_base = vaddr;
info->screen_size = vma->node.size;
info->screen_size = vma->size;
drm_fb_helper_fill_info(info, &ifbdev->helper, sizes);