Commit ae2fb480 authored by Matthew Auld's avatar Matthew Auld Committed by Daniel Vetter
Browse files

drm/i915/gem: consolidate 2big error checking for object sizes 



Throw it into a simple helper, and throw a warning if we encounter an
object which has been initialised with an object size that exceeds our
limit of INT_MAX pages.

Suggested-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarMatthew Auld <matthew.auld@intel.com>
Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20210122181514.541436-2-matthew.auld@intel.com


Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent f63f452e

drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c

+1 −8
Original line number Diff line number Diff line
@@ -244,14 +244,7 @@ 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)

	if (i915_gem_object_size_2big(dma_buf->size))

		return ERR_PTR(-E2BIG);



	/* need to attach */

drivers/gpu/drm/i915/gem/i915_gem_object.h

+26 −0
Original line number Diff line number Diff line
@@ -16,6 +16,32 @@ 
#include "i915_gem_gtt.h"

#include "i915_vma_types.h"



/*

 * 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!

 *

 * Aside from our own locals (for which we have no excuse!):

 * - sg_table embeds unsigned int for num_pages

 * - get_user_pages*() mixed ints with longs

 */

#define GEM_CHECK_SIZE_OVERFLOW(sz) \

	GEM_WARN_ON((sz) >> PAGE_SHIFT > INT_MAX)



static inline bool i915_gem_object_size_2big(u64 size)

{

	struct drm_i915_gem_object *obj;



	if (GEM_CHECK_SIZE_OVERFLOW(size))

		return true;



	if (overflows_type(size, obj->base.size))

		return true;



	return false;

}



void i915_gem_init__objects(struct drm_i915_private *i915);



struct drm_i915_gem_object *i915_gem_object_alloc(void);

drivers/gpu/drm/i915/gem/i915_gem_region.c

+1 −11
Original line number Diff line number Diff line
@@ -161,17 +161,7 @@ i915_gem_object_create_region(struct intel_memory_region *mem, 
	GEM_BUG_ON(!size);

	GEM_BUG_ON(!IS_ALIGNED(size, I915_GTT_MIN_ALIGNMENT));



	/*

	 * 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 (size >> PAGE_SHIFT > INT_MAX)

		return ERR_PTR(-E2BIG);



	if (overflows_type(size, obj->base.size))

	if (i915_gem_object_size_2big(size))

		return ERR_PTR(-E2BIG);



	obj = i915_gem_object_alloc();

drivers/gpu/drm/i915/gem/i915_gem_userptr.c

+1 −15
Original line number Diff line number Diff line
@@ -770,21 +770,7 @@ i915_gem_userptr_ioctl(struct drm_device *dev, 
			    I915_USERPTR_UNSYNCHRONIZED))

		return -EINVAL;



	/*

	 * 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!

	 *

	 * Aside from our own locals (for which we have no excuse!):

	 * - sg_table embeds unsigned int for num_pages

	 * - get_user_pages*() mixed ints with longs

	 */



	if (args->user_size >> PAGE_SHIFT > INT_MAX)

		return -E2BIG;



	if (overflows_type(args->user_size, obj->base.size))

	if (i915_gem_object_size_2big(args->user_size))

		return -E2BIG;



	if (!args->user_size)