From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from AM0PR02CU008.outbound.protection.outlook.com (mail-westeuropeazon11013017.outbound.protection.outlook.com [52.101.72.17]) (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 70859515998 for ; Fri, 18 Sep 2026 16:36:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.72.17 ARC-Seal:i=3; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789749381; cv=fail; b=CIbUndvnHZOOaxSTN42JYv7ZqgeUqTre6P/iWB/ILUuVsm/NCfCrDsrW6WkJ/6skw1UPsg3NSV8eGUOYvh6nXyvhYaXEuYgAtyJZlexG6v6q53jE10b7nRwTWzySBc63rz3QY3EFrsHSnCOdIAzwu1mou6Rhivq2po+7AdA4fgQ= ARC-Message-Signature:i=3; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789749381; c=relaxed/simple; bh=dFkTx3d6jJjmOKHjR6JJA7b3XgcQgWGwK1m0AupnbJs=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=OfIOku3eM1X4GaIn9EJCHXqdnVcE/bZA9sMomoHHRlKwYygQpRHwUeW7m2GMXyq3g/LxdWbv2TQKj5DXlHC5ewgloTjluAjDQjTCrK/gS+AFtNnnP6XfQcNobgxZU5Fj7Nixkd91YUPlgyRUP/639DAgFB48Q6TCIv4sMu6Htw8= ARC-Authentication-Results:i=3; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=lRYNilAr; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=lRYNilAr; arc=fail smtp.client-ip=52.101.72.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="lRYNilAr"; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="lRYNilAr" ARC-Seal: i=2; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=pass; b=vWjE+EX1Ma1fS0QzVkD/I5g9Tov0+bOU27CBBshJNfqR/8VVgLa/BqxjwwJDqPXwB6HOoTxnhNoRBlIfNx3767a3DMRgFcKhgeITcAugXY3Tdvo87Nh92QX8v8FFZDNyJ7zFCIaYISFb2K6r+iPKhjZYyPaWfWrdfdJffxrBizSmB8Y957ARmQ9pcgsNlohSSX64XLjHG1XcG/f1crhkVsGuRSbSzoaXzydFTuZf1a5idtDaRoGdqtJ7o7rgOcxY99KBxpH7g8qaNARYw4NA3BHzKqZkxylKIoxg/AbNcq+fisClMQ6NZ4nYmaDPc5nfkBdYU4F/x2J97DzQ+EfgIQ== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=n6BBk3MICNM5RwkNsux88bydtNdgcd7sseNNy/Yy5Ec=; b=X+24azRn8PjsgFZl0n+OH7CZALDpm7V2GClO7kUPxTlTBrcBCIynCOkymOQ0mA7etvD0da+5tcOipkdKWL9PiBLb0GmEt+3w7lvx2S1MoBz3jozeN+lzMOdIF5qt8lbb6d/FCvVCYbazi/o74NY1AK52qBeS/0Lh1zfWWVyOt6IFpnyi1RYf9IQ8R2Ie9mfSgktaSOkEm0vsSzLgJwzWP0b3o5i33sFHhyNBbpq8rBL20aHX/qnZnXicetT8bGrVbgR5cRZQTFrv0V3Ivk7Upq6a3kmpVLD+lxXQGf/PtGRw/fyocfWZ3re+fLfpkYnC4/rsmk7l17b9Z1H5k0+v0A== ARC-Authentication-Results: i=2; mx.microsoft.com 1; spf=pass (sender ip is 4.158.2.129) smtp.rcpttodomain=collabora.com smtp.mailfrom=arm.com; dmarc=pass (p=none sp=none pct=100) action=none header.from=arm.com; dkim=pass (signature was verified) header.d=arm.com; arc=pass (0 oda=1 ltdi=1 spf=[1,1,smtp.mailfrom=arm.com] dkim=[1,1,header.d=arm.com] dmarc=[1,1,header.from=arm.com]) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arm.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=n6BBk3MICNM5RwkNsux88bydtNdgcd7sseNNy/Yy5Ec=; b=lRYNilArgaVdwfUdR+cjGepuqa306jL8/dWW2KGdSMn6msGJ9DJRMwwY7/Sl5Q7hFaOLtfRPUGLjf128WRLf18ILShApYbMnNFXgHb/hYAxL9dDQZ8qxV2hzzagR15hYwpNbYhZanUGaha3FyX01CTzmRA7D724gupoQ/0pxB9Y= Received: from PR1P264CA0076.FRAP264.PROD.OUTLOOK.COM (2603:10a6:102:2cc::11) by DBAPR08MB5846.eurprd08.prod.outlook.com (2603:10a6:10:1b0::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.451.5; Fri, 18 Sep 2026 16:36:15 +0000 Received: from MI3PEPF0000847F.eurprd02.prod.outlook.com (2603:10a6:102:2cc:cafe::3) by PR1P264CA0076.outlook.office365.com (2603:10a6:102:2cc::11) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.21.428.13 via Frontend Transport; Fri, 18 Sep 2026 16:36:15 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 4.158.2.129) smtp.mailfrom=arm.com; dkim=pass (signature was verified) header.d=arm.com;dmarc=pass action=none header.from=arm.com; Received-SPF: Pass (protection.outlook.com: domain of arm.com designates 4.158.2.129 as permitted sender) receiver=protection.outlook.com; client-ip=4.158.2.129; helo=outbound-uk1.az.dlp.m.darktrace.com; pr=C Received: from outbound-uk1.az.dlp.m.darktrace.com (4.158.2.129) by MI3PEPF0000847F.mail.protection.outlook.com (10.167.240.166) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.21.451.8 via Frontend Transport; Fri, 18 Sep 2026 16:36:14 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=aZCOCSqXUlJPkrshHLuirHqbO9k0YpY2Ohd0+/QAYqUg7jvdC3zi/GdI6DESR1BdP6bGVfAdD+M63weOXqMYsG7CFo+Gq5dUoecqVVFDWJC0aqLY5RHlR0l4kK3kb70Jaqaw0pPKaMpyiBvK82U7sixPHEeiYCnXDOM/m/kmy8uM7u1u9g3iu6Z9tnT4O5oyiJsOK31hpf4szFKNxsOUtJIoE9GmWgcYR9O2y6ilQqzAXi5Fto1eSiEmqkzsBZMfKxw3LnkD/l8xxKa/TCLkIBXrapQUrBZ3fTuhYPfB2oghtQ1wk/AyJqwEIs/EtJT047eR8mZjC7Qp54gAsvhvZw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=n6BBk3MICNM5RwkNsux88bydtNdgcd7sseNNy/Yy5Ec=; b=RbBIw0pl/UoM8x9IVcFBO/14xL6togMX7oeaamf71wJTKbXhikEK3Fi/NLjhHZQlJHkIU2PeJSpJuio+ZLrJmMK73cjZD22ayFTHyv+Hxrqp5EXKdISt3ZQ9WoPk6aeyJKTaNUtRQvIWEUr6JrBd+aJGcdqGDMOKikoxQWEyz9EFb//1LtdrqGKqan2dWrX45qP1dBD40ZK2HXz2ko/DdgyUuxvqd4RzJqTGKsfpYXmRD9Ve2iHOjo9v4yn9OUqW8Xin5pgXMe559Y1kJGgMonD4XU/tS04eanUPV3tAMlmjSMAyNaTsOixPJ+mwqMRNeCGphqVizVjjTjqhCvLFIQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=arm.com; dmarc=pass action=none header.from=arm.com; dkim=pass header.d=arm.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arm.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=n6BBk3MICNM5RwkNsux88bydtNdgcd7sseNNy/Yy5Ec=; b=lRYNilArgaVdwfUdR+cjGepuqa306jL8/dWW2KGdSMn6msGJ9DJRMwwY7/Sl5Q7hFaOLtfRPUGLjf128WRLf18ILShApYbMnNFXgHb/hYAxL9dDQZ8qxV2hzzagR15hYwpNbYhZanUGaha3FyX01CTzmRA7D724gupoQ/0pxB9Y= Authentication-Results-Original: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=arm.com; Received: from GVXPR08MB11744.eurprd08.prod.outlook.com (2603:10a6:150:316::8) by AS8PR08MB9314.eurprd08.prod.outlook.com (2603:10a6:20b:5a5::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.451.5; Fri, 18 Sep 2026 16:35:41 +0000 Received: from GVXPR08MB11744.eurprd08.prod.outlook.com ([fe80::f478:4ce7:8b51:133]) by GVXPR08MB11744.eurprd08.prod.outlook.com ([fe80::f478:4ce7:8b51:133%7]) with mapi id 15.21.0451.004; Fri, 18 Sep 2026 16:35:41 +0000 Message-ID: Date: Fri, 18 Sep 2026 17:35:39 +0100 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/4] drm/panthor: Fix iova_mapped_as_huge_page() for imported BOs To: Boris Brezillon , Steven Price , Liviu Dudau , =?UTF-8?Q?Adri=C3=A1n_Larumbe?= Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, nd@arm.com References: <20260917-panthor-fix-partial-unmap-v1-0-c7008f15fea3@collabora.com> <20260917-panthor-fix-partial-unmap-v1-2-c7008f15fea3@collabora.com> Content-Language: en-US From: Akash Goel In-Reply-To: <20260917-panthor-fix-partial-unmap-v1-2-c7008f15fea3@collabora.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: PA7P264CA0516.FRAP264.PROD.OUTLOOK.COM (2603:10a6:102:3da::9) To GVXPR08MB11744.eurprd08.prod.outlook.com (2603:10a6:150:316::8) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-TrafficTypeDiagnostic: GVXPR08MB11744:EE_|AS8PR08MB9314:EE_|MI3PEPF0000847F:EE_|DBAPR08MB5846:EE_ X-MS-Office365-Filtering-Correlation-Id: fe1bdfe7-5a3a-44fe-d7aa-08df15a2f51f X-LD-Processed: f34e5979-57d9-4aaa-ad4d-b122a662184d,ExtAddr,ExtAddr x-checkrecipientrouted: true NoDisclaimer: true X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam-Untrusted: BCL:0;ARA:13230040|376014|1800799024|23010399003|366016|22082099003|18002099003|11063799006|10067099003|4143699003|56012099006; X-Microsoft-Antispam-Message-Info-Original: 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 X-Forefront-Antispam-Report-Untrusted: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:GVXPR08MB11744.eurprd08.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(1800799024)(23010399003)(366016)(22082099003)(18002099003)(11063799006)(10067099003)(4143699003)(56012099006);DIR:OUT;SFP:1101; X-Exchange-RoutingPolicyChecked: y55BtTbFklTP4gvda9F1UNH4mFBQAvL/R38OfkAyWVmX1ANRyf8cgwPFJcp0rYU4SU2Ln7eSAVnqP0bh9Bg7oNyHKWdZrbJIstTv8/6nJC6RdlltqVyOmn2JK9ekAddCdVDYzqWrqn4MtOhgH8T7D4eaV5XwAjxDoI4WCbN7CiGV40G7fuQ3PA+m20GEruSOy3ujwv943pAIpjEAZxKeKfom7zUHNLGdNFJcKlZEB+oSJnNii4PnJyk99Gz3iSGkf0RXp9Cf/CaUQ7Ii0NUlhofcmfPTcOwLs36t26qFkYkY0AsjLH5WeM5eMmt484TQCIxxu0IFX4wKxIkyQL989w== X-MS-Exchange-Transport-CrossTenantHeadersStamped: AS8PR08MB9314 X-EOPAttributedMessage: 0 X-MS-Exchange-Transport-CrossTenantHeadersStripped: MI3PEPF0000847F.eurprd02.prod.outlook.com X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id-Prvs: dde9e1ca-e807-4ea6-a564-08df15a2e114 X-Microsoft-Antispam: BCL:0;ARA:13230040|23010399003|376014|1800799024|14060799003|35042699022|36860700016|82310400026|10067099003|56012099006|11063799006|22082099003|18002099003|4143699003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:4.158.2.129;CTRY:GB;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:outbound-uk1.az.dlp.m.darktrace.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(23010399003)(376014)(1800799024)(14060799003)(35042699022)(36860700016)(82310400026)(10067099003)(56012099006)(11063799006)(22082099003)(18002099003)(4143699003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 9R2dGmZBcGqcKaRGSsQitHCjl6NE9DD3e2hNPNuRJfQfBCwm2U595TG0bxL6VW2EApxICZo8qJ9zswqSaNkx+/kZYcOexEe+XBrtUwvoF5Fq8vA58HQKV1gSbMP1tPfkaudjh5czXmf+S4abvagL8w8koSPyJQCWs4vaCggp0IlJ5v5dHdhAQtuZsH1CBj6zV33oF8WjLe/mPQv/tI484uPUisbBT5K81EmMZedQynnNnCY1SmDblNtAmqg+PsRe3kvofqfAPP4RyCbxNupS980bm3JXkWYNNE5JdAEv6QBCzKppq+wJa+qmVSPPRz/+TKyROz9bY6anbpFHFi2g/lL3eIjiLrWX6QTLCT7C3lg2s38ouUR1ozNkziV/18aZmV1hR5RTK5w/V8XGdMspqVuGvFSwrr30rUtMIS4BDsTekSgS1RDJ9aBzcaxNE+rx X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 Sep 2026 16:36:14.9638 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: fe1bdfe7-5a3a-44fe-d7aa-08df15a2f51f X-MS-Exchange-CrossTenant-Id: f34e5979-57d9-4aaa-ad4d-b122a662184d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=f34e5979-57d9-4aaa-ad4d-b122a662184d;Ip=[4.158.2.129];Helo=[outbound-uk1.az.dlp.m.darktrace.com] X-MS-Exchange-CrossTenant-AuthSource: MI3PEPF0000847F.eurprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DBAPR08MB5846 On 9/17/26 13:33, Boris Brezillon wrote: > Imported BOs have no backing.pages array allocated, leading to a NULL > deref when iova_mapped_as_huge_page() gets called on them. > > Implement this check through and sgt walk to reach the position of the > sgt targeted by a VA, and check that the DMA address is properly aligned > and the size remaining in the SG entry is bigger than a huge page. > This is basically matching the logic in vm_map_pages(), with get_pgsize() > being replaced by a simpler test, because we don't care about the pgcount > info. > > Reported-by: Akash Goel > Fixes: 8e7460eac786 ("drm/panthor: Support partial unmaps of huge pages") > Signed-off-by: Boris Brezillon > --- Many thanks for fixing the issue Reviewed-by: Akash Goel > drivers/gpu/drm/panthor/panthor_mmu.c | 44 ++++++++++++++++++++++++++++------- > 1 file changed, 36 insertions(+), 8 deletions(-) > > diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c > index b0a7033480e6..6cef954e2cba 100644 > --- a/drivers/gpu/drm/panthor/panthor_mmu.c > +++ b/drivers/gpu/drm/panthor/panthor_mmu.c > @@ -2299,7 +2299,6 @@ iova_mapped_as_huge_page(struct drm_gpuva *mapping, u64 va) > { > struct panthor_gem_object *bo = to_panthor_bo(mapping->gem.obj); > u64 aligned_va = ALIGN_DOWN(va, SZ_2M); > - const struct page *pg; > pgoff_t bo_offset; > > /* If the 2M-aligned VA is outside the mapping being tested, we know > @@ -2309,16 +2308,45 @@ iova_mapped_as_huge_page(struct drm_gpuva *mapping, u64 va) > return false; > > bo_offset = aligned_va - mapping->va.addr + mapping->gem.offset; > - pg = bo->backing.pages[bo_offset >> PAGE_SHIFT]; > > - /* In case of shmem backing, we know we can only have a huge mapping > - * if the bo_offset is 2M aligned, meaning we can skip the folio size > - * check if it's not the case. > - */ > - if (!IS_ALIGNED(bo_offset, SZ_2M)) > + if (drm_gem_is_imported(&bo->base)) { > + struct sg_table *sgt = bo->dmap.sgt; > + struct scatterlist *sgl; > + unsigned int count; > + > + /* If this is an imported BO, we have to walk the SGT and > + * check the dma address/size alignment to determine if it's > + * a huge map or not. > + */ > + for_each_sgtable_dma_sg(sgt, sgl, count) { > + size_t len = sg_dma_len(sgl); > + dma_addr_t daddr; > + > + if (len <= bo_offset) { > + bo_offset -= len; > + continue; > + } > + > + len -= bo_offset; > + daddr = sg_dma_address(sgl) + bo_offset; > + > + return IS_ALIGNED(daddr, SZ_2M) && > + len >= SZ_2M; > + } > + > return false; > + } else { > + const struct page *pg = bo->backing.pages[bo_offset >> PAGE_SHIFT]; > > - return folio_size(page_folio(pg)) >= SZ_2M; > + /* In case of shmem backing, we know we can only have a huge mapping > + * if the bo_offset is 2M aligned, meaning we can skip the folio size > + * check if it's not the case. > + */ > + if (!IS_ALIGNED(bo_offset, SZ_2M)) > + return false; > + > + return folio_size(page_folio(pg)) >= SZ_2M; > + } > } > > static void >