On 25/03/2022 01:03, Chuansheng Liu wrote:

The below memory leak information is caught:

unreferenced object 0xffff997dd4e3b240 (size 64): comm "gem_tiled_fence", pid 10332, jiffies 4294959326 (age 220778.420s) hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 be f2 d4 7d 99 ff ff ............}... backtrace: [<ffffffffa0f04365>] kmem_cache_alloc_trace+0x2e5/0x450 [<ffffffffc062f3ac>] drm_vma_node_allow+0x2c/0xe0 [drm] [<ffffffffc13149ea>] __assign_mmap_offset_handle+0x1da/0x4a0 [i915] [<ffffffffc1315235>] i915_gem_mmap_offset_ioctl+0x55/0xb0 [i915] [<ffffffffc06207e4>] drm_ioctl_kernel+0xb4/0x140 [drm] [<ffffffffc0620ac7>] drm_ioctl+0x257/0x410 [drm] [<ffffffffa0f553ae>] __x64_sys_ioctl+0x8e/0xc0 [<ffffffffa1821128>] do_syscall_64+0x38/0xc0 [<ffffffffa1a0007c>] entry_SYSCALL_64_after_hwframe+0x44/0xae

The issue is always reproduced with the test: gem_tiled_fence_blits --run-subtest basic

It tries to mmap_gtt the same object several times, it is like: create BO mmap_gtt BO unmap BO mmap_gtt BO <== second time mmap_gtt unmap close BO

The leak happens at the second time mmap_gtt in function mmap_offset_attach(),it will simply increase the reference count to 2 by calling drm_vma_node_allow() directly since the mmo has been created at the first time.

However the driver just revokes the vma_node only one time when closing the object, it leads to memory leak easily.

This patch is to fix the memory leak by calling drm_vma_node_allow() one time also.

V2: add "Fixes and Cc stable". (Tvrtko Ursulin)

Fixes: 786555987207 ("drm/i915/gem: Store mmap_offsets in an rbtree rather than a plain list") Cc: stable@vger.kernel.org # v5.7+ Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Tvrtko Ursulin tvrtko.ursulin@intel.com Signed-off-by: Chuansheng Liu chuansheng.liu@intel.com

---

drivers/gpu/drm/i915/gem/i915_gem_mman.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c index c3ea243d414d..fda346d687fd 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c @@ -680,7 +680,7 @@ mmap_offset_attach(struct drm_i915_gem_object *obj, mmo = insert_mmo(obj, mmo); GEM_BUG_ON(lookup_mmo(obj, mmap_type) != mmo); out:

• if (file)

• if (file && !drm_vma_node_is_allowed(&mmo->vma_node, file)) drm_vma_node_allow(&mmo->vma_node, file); return mmo;

Reviewed-by: Tvrtko Ursulin tvrtko.ursulin@intel.com

Regards,

Tvrtko