Commit f63dfc14 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915/selftests: Hold the vma manager lock while modifying mmap_offset 



Right idea, wrong lock. We already drop struct_mutex before we free the
mmap_offset when freeing the object, so we need to take the vma manager
lock when manipulating the mmap_offset address space for our selftests.

Fixes: 8221d21b ("drm/i915/selftests: Lock the drm_mm while modifying")
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: default avatarImre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190711065215.4004-2-chris@chris-wilson.co.uk
parent 5a5efbf4

drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c

+16 −4
Original line number Diff line number Diff line
@@ -401,6 +401,18 @@ static void restore_retire_worker(struct drm_i915_private *i915) 
	i915_gem_shrinker_register(i915);

}



static void mmap_offset_lock(struct drm_i915_private *i915)

	__acquires(&i915->drm.vma_offset_manager->vm_lock)

{

	write_lock(&i915->drm.vma_offset_manager->vm_lock);

}



static void mmap_offset_unlock(struct drm_i915_private *i915)

	__releases(&i915->drm.vma_offset_manager->vm_lock)

{

	write_unlock(&i915->drm.vma_offset_manager->vm_lock);

}



static int igt_mmap_offset_exhaustion(void *arg)

{

	struct drm_i915_private *i915 = arg;
@@ -419,9 +431,9 @@ static int igt_mmap_offset_exhaustion(void *arg) 
	drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {

		resv.start = hole_start;

		resv.size = hole_end - hole_start - 1; /* PAGE_SIZE units */

		mutex_lock(&i915->drm.struct_mutex);

		mmap_offset_lock(i915);

		err = drm_mm_reserve_node(mm, &resv);

		mutex_unlock(&i915->drm.struct_mutex);

		mmap_offset_unlock(i915);

		if (err) {

			pr_err("Failed to trim VMA manager, err=%d\n", err);

			goto out_park;
@@ -485,9 +497,9 @@ static int igt_mmap_offset_exhaustion(void *arg) 
	}



out:

	mutex_lock(&i915->drm.struct_mutex);

	mmap_offset_lock(i915);

	drm_mm_remove_node(&resv);

	mutex_unlock(&i915->drm.struct_mutex);

	mmap_offset_unlock(i915);

out_park:

	restore_retire_worker(i915);

	return err;