From: Chris Wilson Date: Tue, 22 Aug 2017 11:05:17 +0000 (+0100) Subject: drm/i915: Ignore duplicate VMA stored within the per-object handle LUT X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=fa3722f6496640b472bed1613e76da325211d757;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git 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: d1b48c1e7184 ("drm/i915: Replace execbuf vma ht with an idr") Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Cc: Joonas Lahtinen Link: https://patchwork.freedesktop.org/patch/msgid/20170822110517.22277-3-chris@chris-wilson.co.uk Tested-by: Marta Lofstedt Reviewed-by: Michał Winiarski (cherry-picked from commit 3ffff01749928ea5ffdae2cecad561898c3b0f71) Signed-off-by: Rodrigo Vivi --- diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index a54a9631f59e..825d75c548b8 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -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); diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index 25b14d492d91..944e9e543573 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -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; diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h index 1fd61e88cfd0..e811067c7724 100644 --- a/drivers/gpu/drm/i915/i915_vma.h +++ b/drivers/gpu/drm/i915/i915_vma.h @@ -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