From nobody Mon Feb 9 08:15:23 2026 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) (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 88AE31F94C for ; Fri, 7 Mar 2025 03:04:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.168.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741316660; cv=none; b=VpmEYDrkwqOLLvtWUUXQa8aLs6xchPQne9WoNuW/qtH32zYosxLpAxpQl9ikzA6HWaLsHN4Cxkxhwsgrdkeck7pW1Lg0CfQjcvvSeED6QHG7yFQD1m5iFk93HmbY3kAzRMbzAv9tpsu5dg9QJJc8QAQVoAuJsDZYA3qYyq4fYTU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741316660; c=relaxed/simple; bh=XCP9kwKztjB5aMRSK3OlQNdJX12K71O8wDs8oAclikE=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=BWITi0mLfOgsbn/YuAFcdy/ZJtOCnuv6Hu1t2Vayb/USiuHUpiAoDdPESI9wlsGFUDRcQWZYz55jrQz645E97suU++fobS/GyCiupHYJ3a2tmyeu10hqndHhdCEhcnfO4RohylI6YDWIjPJp4DlZbwoB5PBOFak7BAxsslYUbvI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com; spf=pass smtp.mailfrom=quicinc.com; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b=PCxkC9Dl; arc=none smtp.client-ip=205.220.168.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=quicinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b="PCxkC9Dl" Received: from pps.filterd (m0279862.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 526FYWPh017935; Fri, 7 Mar 2025 03:04:03 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h= cc:content-transfer-encoding:content-type:date:from:message-id :mime-version:subject:to; s=qcppdkim1; bh=IEawcTkCI3WN0tBwh7VLst cfdDPbM0A0inPDwTtdLlo=; b=PCxkC9Dl73FlMap8NTr17C4MOwX8bvU2wk+ESb oDFQbnCddwvn/W5ChLbZIUgCxUwo/wKl3UJMxUMv+VHtVx+utt5Zhvte5uYHw3m/ ReGUQ25ElHiTu14zANCqEVYu58UhX+ZXlFxsvNPkz+jMku+caRD0ZaPVxzCkFhSZ xjHzYmJ7y9qjyLbcxLhLUMfmLCiZY6nbavMFKc83+jTNcC+6RRz88FpUXkNwJzX7 deJqYTQj1XJZN+FvmLrlbNvbHWNHShZCr8YV4y+UPpPNdeARMUPCqH/4Yc/x6goe /sP3/bq9itBVWHwBKaj1m8KcP9iwg+Nn1D56J1zXKHZxs4tA== Received: from nalasppmta02.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 45778tb0x4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 07 Mar 2025 03:04:03 +0000 (GMT) Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA02.qualcomm.com (8.18.1.2/8.18.1.2) with ESMTPS id 527342ks011599 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 7 Mar 2025 03:04:02 GMT Received: from Z2G9.lan (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.9; Thu, 6 Mar 2025 19:04:00 -0800 From: Baochen Qiang To: , , , CC: , , Subject: [PATCH] dma-mapping: fix missing clear bdr in check_ram_in_range_map() Date: Fri, 7 Mar 2025 11:03:50 +0800 Message-ID: <20250307030350.69144-1-quic_bqiang@quicinc.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: IA4xNB-LbgoUeq15A9bmdWCUt3KXcaLk X-Authority-Analysis: v=2.4 cv=U5poDfru c=1 sm=1 tr=0 ts=67ca6223 cx=c_pps a=ouPCqIW2jiPt+lZRy3xVPw==:117 a=ouPCqIW2jiPt+lZRy3xVPw==:17 a=GEpy-HfZoHoA:10 a=Vs1iUdzkB0EA:10 a=VwQbUJbxAAAA:8 a=COk6AnOGAAAA:8 a=6YtNXFjIWaMwA3fUu04A:9 a=TjNXssC_j7lpFel5tvFf:22 X-Proofpoint-GUID: IA4xNB-LbgoUeq15A9bmdWCUt3KXcaLk X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1093,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-03-07_01,2025-03-06_04,2024-11-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 impostorscore=0 phishscore=0 lowpriorityscore=0 suspectscore=0 spamscore=0 mlxlogscore=999 adultscore=0 clxscore=1011 malwarescore=0 bulkscore=0 mlxscore=0 classifier=spam authscore=0 authtc=n/a authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2502100000 definitions=main-2503070018 Content-Type: text/plain; charset="utf-8" As discussed in [1], if 'bdr' is set once, it would never get cleared, hence 0 is always returned. Refactor the range check hunk into a new helper dma_find_range(), which allows 'bdr' to be cleared in each iteration. Link: https://lore.kernel.org/all/64931fac-085b-4ff3-9314-84bac2fa9bdb@quic= inc.com/ # [1] Fixes: a409d9600959 ("dma-mapping: fix dma_addressing_limited() if dma_rang= e_map can't cover all system RAM") Suggested-by: Christoph Hellwig Signed-off-by: Baochen Qiang --- kernel/dma/direct.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 5b4e6d3bf7bc..b8fe0b3d0ffb 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -584,6 +584,22 @@ int dma_direct_supported(struct device *dev, u64 mask) return mask >=3D phys_to_dma_unencrypted(dev, min_mask); } =20 +static const struct bus_dma_region *dma_find_range(struct device *dev, + unsigned long start_pfn) +{ + const struct bus_dma_region *m; + + for (m =3D dev->dma_range_map; PFN_DOWN(m->size); m++) { + unsigned long cpu_start_pfn =3D PFN_DOWN(m->cpu_start); + + if (start_pfn >=3D cpu_start_pfn && + start_pfn - cpu_start_pfn < PFN_DOWN(m->size)) + return m; + } + + return NULL; +} + /* * To check whether all ram resource ranges are covered by dma range map * Returns 0 when further check is needed @@ -593,20 +609,12 @@ static int check_ram_in_range_map(unsigned long start= _pfn, unsigned long nr_pages, void *data) { unsigned long end_pfn =3D start_pfn + nr_pages; - const struct bus_dma_region *bdr =3D NULL; - const struct bus_dma_region *m; struct device *dev =3D data; =20 while (start_pfn < end_pfn) { - for (m =3D dev->dma_range_map; PFN_DOWN(m->size); m++) { - unsigned long cpu_start_pfn =3D PFN_DOWN(m->cpu_start); + const struct bus_dma_region *bdr; =20 - if (start_pfn >=3D cpu_start_pfn && - start_pfn - cpu_start_pfn < PFN_DOWN(m->size)) { - bdr =3D m; - break; - } - } + bdr =3D dma_find_range(dev, start_pfn); if (!bdr) return 1; =20 base-commit: 7eb172143d5508b4da468ed59ee857c6e5e01da6 --=20 2.34.1