Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit fa3722f6 authored by Chris Wilson's avatar Chris Wilson Committed by Rodrigo Vivi
Browse files

drm/i915: Ignore duplicate VMA stored within the per-object handle LUT 

By using drm_gem_flink/drm_gem_open on an object using the same fd, it
is possible for a client to create multiple handles pointing to the same
object (tied to the same contexts and VMA), as exemplified by
igt::gem_handle_to_libdrm_bo(). Since this duplication has been possible
since forever, we cannot assume that the handle:(fpriv, object) is
unique and so must handle the multiple users of a single VMA.

v2: Added commentary noise.

Testcase: igt/gem_close
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102355


Fixes: d1b48c1e ("drm/i915: Replace execbuf vma ht with an idr")
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170822110517.22277-3-chris@chris-wilson.co.uk


Tested-by: default avatarMarta Lofstedt <marta.lofstedt@intel.com>
Reviewed-by: default avatarMichał Winiarski <michal.winiarski@intel.com>
(cherry-picked from commit 3ffff017)
Signed-off-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
parent 18db229d

drivers/gpu/drm/i915/i915_gem.c

+7 −1
Original line number Diff line number Diff line
@@ -3262,7 +3262,13 @@ void i915_gem_close_object(struct drm_gem_object *gem, struct drm_file *file) 


		vma = radix_tree_delete(&ctx->handles_vma, lut->handle);



		if (!i915_vma_is_ggtt(vma))

		GEM_BUG_ON(vma->obj != obj);



		/* We allow the process to have multiple handles to the same

		 * vma, in the same fd namespace, by virtue of flink/open.

		 */

		GEM_BUG_ON(!vma->open_count);

		if (!--vma->open_count && !i915_vma_is_ggtt(vma))

			i915_vma_close(vma);



		list_del(&lut->obj_link);

drivers/gpu/drm/i915/i915_gem_execbuffer.c

+1 −0
Original line number Diff line number Diff line
@@ -720,6 +720,7 @@ static int eb_lookup_vmas(struct i915_execbuffer *eb) 
			goto err_obj;

		}



		vma->open_count++;

		list_add(&lut->obj_link, &obj->lut_list);

		list_add(&lut->ctx_link, &eb->ctx->handles_list);

		lut->ctx = eb->ctx;

drivers/gpu/drm/i915/i915_vma.h

+6 −0
Original line number Diff line number Diff line
@@ -59,6 +59,12 @@ struct i915_vma { 
	u32 fence_size;

	u32 fence_alignment;



	/**

	 * Count of the number of times this vma has been opened by different

	 * handles (but same file) for execbuf, i.e. the number of aliases

	 * that exist in the ctx->handle_vmas LUT for this vma.

	 */

	unsigned int open_count;

	unsigned int flags;

	/**

	 * How many users have pinned this object in GTT space. The following