From mboxrd@z Thu Jan 1 00:00:00 1970 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 2499C194098 for ; Mon, 19 May 2025 10:56:33 +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=1747652195; cv=none; b=bEOeF5nchf5F02iC54ZSYMP69R4NSzflF0FJiptlUaoXGzncW7Z8r93bopLY8qKQOvjyHGF873zAPcqUad0z1LlM/ambR08GkoSi59CH+AhU2p9BQsdQ0W1u/uppOKS8SKYO32Mew5Lx2/8Dmpot2yH4e3GiiIiylDtdf4LO84o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747652195; c=relaxed/simple; bh=6KNwkQkdS02ZNTfPVH7I0FPPpkZXF79WoUmr5cAUn7k=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=en9DkIxqB3Bya95u4t7+N+sZmw1rrnYdsnHZV/wSxZkSUwoybKHs4Kf4UHf70e5S/2YkqFm95ag+aDrxZTrsGjlRH8bSDK+O8oT9f8cU99aqk5HWBhcbtcM+QHMGvwitLgOzWKa+G+M+nfbcIfimzqO7ztbqxLl20s7MMqnUrJ0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com; spf=pass smtp.mailfrom=oss.qualcomm.com; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b=lxpgE3K7; arc=none smtp.client-ip=205.220.168.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b="lxpgE3K7" Received: from pps.filterd (m0279864.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 54J6OTLf006095 for ; Mon, 19 May 2025 10:56:33 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qualcomm.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= h1/td3vHUmHobFaVyqHJ4J+uwRZH9mDOdhLlH4XEhBc=; b=lxpgE3K7v51i7KPQ MIBlQpZaKkVeNN5/D/BLWURS4d1A6kKGVEKQm+DBSFtyJ2apYJGyDHH43TYv+G8H /+n2G+1w6JZBizk+eU5aUUO107oLm2DfNZeFZofF9n+yS3azxJ91gdIvnECImVXs cXQymdhE/w1KbmjUoC8G/M31Yd9bq2Ym4wrNlrJOC/fD8q4JDEkfA3X4inmtQ/Zq zPeGkxOC0jqH1ewhYkIuZvfmQxtNo4MehJkM4iVRPyH8iaUKbCAhWbwiYX6Xq4L8 jRGLnkbWK8LakTWlhORIKMJM35/AvNlc/P0/HyQtzoTGP74i3ZAgThmNyGFAPSfk SGPCpA== Received: from mail-pf1-f199.google.com (mail-pf1-f199.google.com [209.85.210.199]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 46qybkgu3s-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 19 May 2025 10:56:33 +0000 (GMT) Received: by mail-pf1-f199.google.com with SMTP id d2e1a72fcca58-742b8c0eaf0so980650b3a.2 for ; Mon, 19 May 2025 03:56:33 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1747652192; x=1748256992; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=h1/td3vHUmHobFaVyqHJ4J+uwRZH9mDOdhLlH4XEhBc=; b=mPcrIGTEs+CXd5p7aZacE9vAhk30vc8XLsRdKeoYlPjbr7dtU2TiHU5GfuuSvxHYnl vh1bFNpPmVnnyb6AXxS/xEL/MCQytaxRk738tOQ5udV2LQrBVM1zXipNHq3Ng/SZh7/w U64nFxjc6BSn9oSe2YvLu8fA9s2fchDaJA/NCM9G8a49AhjO4RIDoCaa0FicFMh/vzwY 3i9b1ggeH1hxOE/VpY0BDb5b6X0Fp8g1cbnW13l44I6fyyYUGRXfghN8INV6udaZhssc yv0sXr8hF9XnAiTi/RAsHWIjekZvhwYFdfdfKNbfB74+UvjH2iRCG7bRznvAHB9c5dv+ AUeg== X-Forwarded-Encrypted: i=1; AJvYcCV/Yt58qy4EWbSAlK5gJPdZdeARWKI0RYaSGxYjcx7Zk8ekRH1HfsB5E1/0sVNZ7nznL/5VkM0YZESAxbM=@vger.kernel.org X-Gm-Message-State: AOJu0YxjtphdQFa59EZOlUKNCa03uIOq1fqerTnkEu+D4V07f6XDEItl hWYN0dHb3oDK+dfXmIx0lcSdP4vlwAzcgvozMzv2aMnYl34b1cbkMxXBudRhZK9qPtMIm8pPvrd zjnvx8sVDKwjWF0T+1QNyXPj5IQmvUWhe0MQY3SXwHVay+yFctNXYEvw+o2n0CJZG6KE= X-Gm-Gg: ASbGncsDof+GBrFMjocs3VI5XDZSVDdCJhvTcpBTzgoinxB5P+xUyviiGoygxG3wh0c 3Fs/ZMmkruITyjJzdBy6XRQesJHYpBZMUAXMYe7eEAId5LDulxcOqkG4sDJusD3SCJ8U37Vsguu 3GwyUwZf6H+eFnvcjjWA4s2zB5jGdGat9IYyj1DOPmV22TO655uiZJ8VyPPl9ZyYqHfs6CqrGdi ZTy9rtcmi09R5vNglgU5N1X/S6OsySRiia+33mV2DCfequyjrbDXTza7eLq+6mzys7LpdZjIIbz e9mNVp8+Su9mNj8iv2My5tii6knBHXFuWzIZMw== X-Received: by 2002:a05:6a21:900c:b0:1f5:790c:947 with SMTP id adf61e73a8af0-216218f7a98mr16582743637.19.1747652192308; Mon, 19 May 2025 03:56:32 -0700 (PDT) X-Google-Smtp-Source: AGHT+IE+YEl4DPCmiC1kC569JIh9uPvjA+HhDzxAzt9PU6GwUL7mcjSbRxgYRKdYtvvk4K1w9WTdTg== X-Received: by 2002:a05:6a21:900c:b0:1f5:790c:947 with SMTP id adf61e73a8af0-216218f7a98mr16582715637.19.1747652191912; Mon, 19 May 2025 03:56:31 -0700 (PDT) Received: from [10.204.65.175] ([202.46.23.25]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-742a96dfaefsm5947008b3a.33.2025.05.19.03.56.28 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 19 May 2025 03:56:31 -0700 (PDT) Message-ID: <1246b4e6-dd1f-4293-b580-5d642f661956@oss.qualcomm.com> Date: Mon, 19 May 2025 16:26:27 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 4/5] misc: fastrpc: Remove buffer from list prior to unmap operation To: Dmitry Baryshkov Cc: srinivas.kandagatla@oss.qualcomm.com, linux-arm-msm@vger.kernel.org, gregkh@linuxfoundation.org, quic_bkumar@quicinc.com, linux-kernel@vger.kernel.org, quic_chennak@quicinc.com, dri-devel@lists.freedesktop.org, arnd@arndb.de, stable@kernel.org References: <20250513042825.2147985-1-ekansh.gupta@oss.qualcomm.com> <20250513042825.2147985-5-ekansh.gupta@oss.qualcomm.com> Content-Language: en-US From: Ekansh Gupta In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Proofpoint-GUID: B18jYbnoLOu5AMHHEhj2nkdLHWZFLqB8 X-Proofpoint-ORIG-GUID: B18jYbnoLOu5AMHHEhj2nkdLHWZFLqB8 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwNTE5MDEwMyBTYWx0ZWRfX9geP7ZPjYPim DLjjehItp7itiT+IHvF9tTVR05upd9Ifn1IHXzdg58pz/240YYzHyM0ZUrLTRwtN76/LVZYN+AY fV0zkTvVgNcx+GXILSOSR6zZ0VKTd141T+fQTjNmXfiFvJGQ+jAwuFGS2TQmq5hFi/qbP/YND8H 6R5ptP0b2abXXz/km88g00cTiMnNSGpBpRWUsHF9A+eepLG+eicgy7NfNpOnKq7Bq+AHfna7bgo gRYp/RBQBcFmszvNZCWgKyjzKWIVfxenQdqIvijC6E4r5dYGP9huMo5ZptsMWdtZU1XUdVAyup5 qtxqlsw1SyfJFNd4DPDazV0x1MpIdj4RMBRrDBn7gNlMHjWCMtwD8f7gzbdJULt6aLa95eqbq8c SuH1GIElII7Kn5snTeitJ/ZMPuZ3x+fRzEOcsEOJxqzc7IHGMrNiacG6YnX3lgTIVaM8/y/C X-Authority-Analysis: v=2.4 cv=RZeQC0tv c=1 sm=1 tr=0 ts=682b0e61 cx=c_pps a=WW5sKcV1LcKqjgzy2JUPuA==:117 a=ZePRamnt/+rB5gQjfz0u9A==:17 a=IkcTkHD0fZMA:10 a=dt9VzEwgFbYA:10 a=VwQbUJbxAAAA:8 a=EUspDBNiAAAA:8 a=X88mIgiXdH4OVKoEc0MA:9 a=QEXdDO2ut3YA:10 a=OpyuDcXvxspvyRM73sMx:22 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.0.736,FMLib:17.12.80.40 definitions=2025-05-19_04,2025-05-16_03,2025-03-28_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 bulkscore=0 phishscore=0 mlxlogscore=999 malwarescore=0 priorityscore=1501 clxscore=1015 lowpriorityscore=0 mlxscore=0 suspectscore=0 impostorscore=0 adultscore=0 classifier=spam authscore=0 authtc=n/a authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2505070000 definitions=main-2505190103 On 5/19/2025 3:50 PM, Dmitry Baryshkov wrote: > On Tue, May 13, 2025 at 09:58:24AM +0530, Ekansh Gupta wrote: >> fastrpc_req_munmap_impl() is called to unmap any buffer. The buffer is >> getting removed from the list after it is unmapped from DSP. This can >> create potential race conditions if any other thread removes the entry >> from list while unmap operation is ongoing. Remove the entry before >> calling unmap operation. >> >> Fixes: 2419e55e532de ("misc: fastrpc: add mmap/unmap support") >> Cc: stable@kernel.org >> Signed-off-by: Ekansh Gupta >> --- >> drivers/misc/fastrpc.c | 29 ++++++++++++++++++++++------- >> 1 file changed, 22 insertions(+), 7 deletions(-) >> >> diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c >> index b629e24f00bc..d54368bf8c5c 100644 >> --- a/drivers/misc/fastrpc.c >> +++ b/drivers/misc/fastrpc.c >> @@ -1868,9 +1868,6 @@ static int fastrpc_req_munmap_impl(struct fastrpc_user *fl, struct fastrpc_buf * >> &args[0]); >> if (!err) { >> dev_dbg(dev, "unmmap\tpt 0x%09lx OK\n", buf->raddr); >> - spin_lock(&fl->lock); >> - list_del(&buf->node); >> - spin_unlock(&fl->lock); >> fastrpc_buf_free(buf); >> } else { >> dev_err(dev, "unmmap\tpt 0x%09lx ERROR\n", buf->raddr); >> @@ -1884,13 +1881,15 @@ static int fastrpc_req_munmap(struct fastrpc_user *fl, char __user *argp) >> struct fastrpc_buf *buf = NULL, *iter, *b; >> struct fastrpc_req_munmap req; >> struct device *dev = fl->sctx->dev; >> + int err; >> >> if (copy_from_user(&req, argp, sizeof(req))) >> return -EFAULT; >> >> spin_lock(&fl->lock); >> list_for_each_entry_safe(iter, b, &fl->mmaps, node) { >> - if ((iter->raddr == req.vaddrout) && (iter->size == req.size)) { >> + if (iter->raddr == req.vaddrout && iter->size == req.size) { > Cosmetics, please drop. Ack. > >> + list_del(&iter->node); >> buf = iter; >> break; >> } >> @@ -1903,7 +1902,14 @@ static int fastrpc_req_munmap(struct fastrpc_user *fl, char __user *argp) >> return -EINVAL; >> } >> >> - return fastrpc_req_munmap_impl(fl, buf); >> + err = fastrpc_req_munmap_impl(fl, buf); >> + if (err) { >> + spin_lock(&fl->lock); >> + list_add_tail(&buf->node, &fl->mmaps); >> + spin_unlock(&fl->lock); >> + } >> + >> + return err; >> } >> >> static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp) >> @@ -1997,14 +2003,23 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp) >> >> if (copy_to_user((void __user *)argp, &req, sizeof(req))) { >> err = -EFAULT; >> - goto err_assign; >> + goto err_copy; >> } >> >> dev_dbg(dev, "mmap\t\tpt 0x%09lx OK [len 0x%08llx]\n", >> buf->raddr, buf->size); >> >> return 0; >> - > Please keep the empty line here, it improves readability. Ack. > >> +err_copy: >> + if (req.flags == ADSP_MMAP_REMOTE_HEAP_ADDR) { >> + spin_lock_irqsave(&fl->cctx->lock, flags); >> + list_del(&buf->node); >> + spin_unlock_irqrestore(&fl->cctx->lock, flags); >> + } else { >> + spin_lock(&fl->lock); >> + list_del(&buf->node); >> + spin_unlock(&fl->lock); >> + } > Can we store the spinlock pointer in the struct fastrpc_buf instead? this spinlock is used for multiple lists(bufs, maps and ctx). > >> err_assign: >> fastrpc_req_munmap_impl(fl, buf); >> >> -- >> 2.34.1 >>