linux-kernel - [PATCH] Use drm_gem_shmem_unpin() to unpin the backing pages for a shmem GEM

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250827022516.2890226-1-xiaolei.wang@windriver.com>
Date: Wed, 27 Aug 2025 10:25:16 +0800
From: Xiaolei Wang <xiaolei.wang@...driver.com>
To: maarten.lankhorst@...ux.intel.com, mripard@...nel.org, tzimmermann@...e.de,
        dmitry.baryshkov@....qualcomm.com, airlied@...il.com, simona@...ll.ch,
        dmitry.osipenko@...labora.com, boris.brezillon@...labora.com
Cc: dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: [PATCH] Use drm_gem_shmem_unpin() to unpin the backing pages for a shmem GEM

Although drm_gem_shmem_free() will decrease the use count
on the backing pages and free backing pages for a GEM object,
the pages_pin_count count is not decremented, which results
in a warning. Therefore, use drm_gem_shmem_unpin() to unpin
the backing pages for a shmem GEM.

WARNING: CPU: 2 PID: 1106 at drivers/gpu/drm/drm_gem_shmem_helper.c:180 drm_gem_shmem_free+0x4d0/0x6f0
 Call trace:
  drm_gem_shmem_free+0x4d0/0x6f0 (P)
  drm_gem_shmem_free_wrapper+0x10/0x1c
  __kunit_action_free+0x50/0x70
  kunit_remove_resource+0x144/0x1e4
  kunit_cleanup+0x64/0xfc
  kunit_try_run_case_cleanup+0xa0/0xd4
  kunit_generic_run_threadfn_adapter+0x80/0xec
  kthread+0x3b8/0x6c0
  ret_from_fork+0x10/0x20

Fixes: 93032ae634d4 ("drm/test: add a test suite for GEM objects backed by shmem")
Signed-off-by: Xiaolei Wang <xiaolei.wang@...driver.com>
---
 drivers/gpu/drm/tests/drm_gem_shmem_test.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
index 68f2c3162354..e0a9f3a917ed 100644
--- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
+++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
@@ -227,6 +227,7 @@ static void drm_gem_shmem_test_get_pages_sgt(struct kunit *test)
 		len += sg->length;
 	}
 
+	drm_gem_shmem_unpin(shmem);
 	KUNIT_EXPECT_GE(test, len, TEST_SIZE);
 }
 
-- 
2.43.0