From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E5757274650; Thu, 30 Jul 2026 15:38:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785425882; cv=none; b=XTMbrTRbsvrDiqPNEiiB5NNup03hUN5UPXMWyV+jTyc6BlYw/lIkfDVCT6SfTJo1f8tjBx9VWZ+KGeqVIiGwmcIBPVg5NMPwpUNWcAJ6l1Yp767MiJKIiR4ORWeqGucms8+RJiu80LqpwVyx4TsqSV+A3bxDCe4Cksivts2uLuY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785425882; c=relaxed/simple; bh=zJnLSZejlmOn45DLmQGY1YPenv6V7VI9Z7hIQGHnKss=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=IqZX0GsMzvsEhodI/toilax2oE8kutzEksn25Uxf1M3o9Olw656aZN93NQSQ6Uy9A5Y7WiUGi+UBjOB52qUcBv/sgbtm0595p2UYzTq1gXTwNc1mfCQMbDTDlhewED0ssijzofuUw7nF8/zaEjf+0EPZBBIn1uD39V+mPaEO2UU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=z1V58iTq; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="z1V58iTq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 491FA1F00AC4; Thu, 30 Jul 2026 15:38:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785425880; bh=hpqniXzfjyjSkmYsCBob9ugPGukjMsfb3YL8SS0g59k=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=z1V58iTq1U5SXT2yb8KVBTX6uUw7YQUnV5iJV5nWIULWnw8Gvs+m9Xp1FzLJ6sDHq FFFsKPKLoMuA9KrzVEdNoqTGBYJY1XwG5r0g7SuJD7TKuxnPN7CZHA109w+QsqVgmp UPp86d5c8/VCflMnbB0J5HUWaLkDbopGyaTuHTmU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Thomas Zimmermann , =?UTF-8?q?Jos=C3=A9=20Exp=C3=B3sito?= , Sasha Levin Subject: [PATCH 6.12 223/602] drm/tests: shmem: Set DMA mask to 64-bit in drm_gem_shmem Date: Thu, 30 Jul 2026 16:10:15 +0200 Message-ID: <20260730141440.645182705@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260730141435.976815864@linuxfoundation.org> References: <20260730141435.976815864@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: José Expósito [ Upstream commit b04a248cfa6cfa1e7dc9ce91cb1eb88b1a70dd69 ] drm_gem_shmem_test_purge [1] and drm_gem_shmem_test_get_pages_sgt [2] intermittently fail on ppc64le and s390x CI systems with a DMA address overflow: DMA addr 0x0000000100307000+4096 overflow (mask ffffffff, bus limit 0) WARNING: kernel/dma/direct.h:114 dma_direct_map_sg+0x778/0x920 drm_gem_shmem_test_purge: ASSERTION FAILED at drivers/gpu/drm/tests/drm_gem_shmem_test.c:330 Expected sgt is not error, but is: -5 The call chain leading to the failure is: drm_gem_shmem_test_purge() / drm_gem_shmem_test_get_pages_sgt() drm_gem_shmem_get_pages_sgt() drm_gem_shmem_get_pages_sgt_locked() [drm_gem_shmem_helper.c] dma_map_sgtable() [mapping.c] __dma_map_sg_attrs() dma_direct_map_sg() [direct.c] dma_direct_map_phys() [kernel/dma/direct.h] dma_capable() Checks addr against DMA mask -> FAILS: addr > 0xFFFFFFFF The root cause is that KUnit devices are initialized with a 32-bit DMA mask (DMA_BIT_MASK(32)) in lib/kunit/device.c. On ppc64le and s390x systems with physical memory above 4GB, page allocations can land at addresses that exceed this mask. When drm_gem_shmem_get_pages_sgt() attempts to DMA-map these pages via dma_map_sgtable(), the DMA layer rejects the mapping because the physical address overflows the 32-bit mask. The failure is intermittent because pages may or may not be allocated above 4GB on any given run depend on memory pressure. Fix by setting a 64-bit DMA mask on the device before calling drm_gem_shmem_get_pages_sgt() for all tests, following the same pattern already used in drm_gem_shmem_test_obj_create_private(). [1] https://s3.amazonaws.com/arr-cki-prod-trusted-artifacts/trusted-artifacts/2643976103/test_s390x/15128551935/artifacts/jobwatch/logs/recipes/21561049/tasks/220716793/results/1014626315/logs/dmesg.log [2] https://s3.amazonaws.com/arr-cki-prod-trusted-artifacts/trusted-artifacts/2643976103/test_ppc64le/15128551933/artifacts/jobwatch/logs/recipes/21561041/tasks/220716705/results/1014628163/logs/dmesg.log Fixes: 93032ae634d4 ("drm/test: add a test suite for GEM objects backed by shmem") Closes: https://datawarehouse.cki-project.org/issue/5345 Closes: https://datawarehouse.cki-project.org/issue/3184 Assisted-by: Claude:claude-4.6-opus Reviewed-by: Thomas Zimmermann Signed-off-by: José Expósito Link: https://patch.msgid.link/20260703150808.3832-1-jose.exposito89@gmail.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/tests/drm_gem_shmem_test.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c b/drivers/gpu/drm/tests/drm_gem_shmem_test.c index 0c8c46ca158c06..cc40d63ab809e7 100644 --- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c +++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c @@ -90,13 +90,9 @@ static void drm_gem_shmem_test_obj_create_private(struct kunit *test) sg_init_one(sgt->sgl, buf, TEST_SIZE); /* - * Set the DMA mask to 64-bits and map the sgtables - * otherwise drm_gem_shmem_free will cause a warning - * on debug kernels. + * Map the sgtables otherwise drm_gem_shmem_free will cause a warning on + * debug kernels. */ - ret = dma_set_mask(drm_dev->dev, DMA_BIT_MASK(64)); - KUNIT_ASSERT_EQ(test, ret, 0); - ret = dma_map_sgtable(drm_dev->dev, sgt, DMA_BIDIRECTIONAL, 0); KUNIT_ASSERT_EQ(test, ret, 0); @@ -342,11 +338,19 @@ static int drm_gem_shmem_test_init(struct kunit *test) { struct device *dev; struct drm_device *drm_dev; + int ret; /* Allocate a parent device */ dev = drm_kunit_helper_alloc_device(test); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev); + /* + * Set the DMA mask to 64-bits to avoid intermittent failures calling + * drm_gem_shmem_get_pages_sgt(). + */ + ret = dma_set_mask(dev, DMA_BIT_MASK(64)); + KUNIT_ASSERT_EQ(test, ret, 0); + /* * The DRM core will automatically initialize the GEM core and create * a DRM Memory Manager object which provides an address space pool -- 2.53.0