drm/i915: Handle vm_mmap error during I915_GEM_MMAP ioctl with WC set (ebfb6977) · Commits · 戴 / test

Add err goto label and use it when VMA can't be established or changes underneath. v2: - Dropping Fixes: as it's indeed impossible to race an object to the error address. (Chris) v3: - Use IS_ERR_VALUE (Chris) Reported-by:

Adam Zabrocki <adamza@microsoft.com> Signed-off-by:

Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Adam Zabrocki <adamza@microsoft.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> #v2 Reviewed-by:

Chris Wilson <chris@chris-wilson.co.uk> Link: https://patchwork.freedesktop.org/patch/msgid/20190207085454.10598-2-joonas.lahtinen@linux.intel.com

drivers/gpu/drm/i915/i915_gem.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -1738,6 +1738,9 @@ i915_gem_mmap_ioctl(struct drm_device dev, void data,
		addr = vm_mmap(obj->base.filp, 0, args->size,
		PROT_READ \| PROT_WRITE, MAP_SHARED,
		args->offset);
		if (IS_ERR_VALUE(addr))
		goto err;

		if (args->flags & I915_MMAP_WC) {
		struct mm_struct *mm = current->mm;
		struct vm_area_struct *vma;
		@@ -1753,17 +1756,22 @@ i915_gem_mmap_ioctl(struct drm_device dev, void data,
		else
		addr = -ENOMEM;
		up_write(&mm->mmap_sem);
		if (IS_ERR_VALUE(addr))
		goto err;

		/* This may race, but that's ok, it only gets set */
		WRITE_ONCE(obj->frontbuffer_ggtt_origin, ORIGIN_CPU);
		}
		i915_gem_object_put(obj);
		if (IS_ERR((void *)addr))
		return addr;

		args->addr_ptr = (u64)addr;

		return 0;

		err:
		i915_gem_object_put(obj);

		return addr;
		}

		static unsigned int tile_row_pages(const struct drm_i915_gem_object *obj)

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