drm/i915/gem: don't trust the dma_buf->size

At least for the time being, we need to limit our object sizes such that
the number of pages can fit within a 32b signed int. It looks like we
should also apply the same restriction to any imported dma-buf.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20210122181514.541436-1-matthew.auld@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Matthew Auld 2021-01-22 18:15:13 +00:00 committed by Daniel Vetter
parent 041b7f0762
commit f63f452ea6

View file

@ -244,6 +244,16 @@ struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
} }
} }
/*
* XXX: There is a prevalence of the assumption that we fit the
* object's page count inside a 32bit _signed_ variable. Let's document
* this and catch if we ever need to fix it. In the meantime, if you do
* spot such a local variable, please consider fixing!
*/
if (dma_buf->size >> PAGE_SHIFT > INT_MAX)
return ERR_PTR(-E2BIG);
/* need to attach */ /* need to attach */
attach = dma_buf_attach(dma_buf, dev->dev); attach = dma_buf_attach(dma_buf, dev->dev);
if (IS_ERR(attach)) if (IS_ERR(attach))