drm/i915: Handle vm_mmap error during I915_GEM_MMAP ioctl with WC set

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
This commit is contained in:
Joonas Lahtinen 2019-02-07 10:54:54 +02:00
parent 5c4604e757
commit ebfb697780

View file

@ -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)