From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailout4.samsung.com (mailout4.samsung.com [203.254.224.34]) (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 84DE02F3E for ; Mon, 23 Dec 2024 02:14:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=203.254.224.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734920075; cv=none; b=otCk6xhMT+yTYEG//lOQVoSnS+6ckp/Oc0FwFYegFQ/v1KDjHUVDmQFPV4mgBiXm/gaN7gaGnLhzUrXn/DASD49zSqOL7CF3+2DFAtUs6h05j1b6Ni8UhnGdcPq8YbJZfynZpudvq1wzVmEbThOZgFMQPlk2FfP/0fEpDIErywQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734920075; c=relaxed/simple; bh=c4mdwcxcN7uUzUqzZPO+90GO9wIv3nNZkWJW+auXCrM=; h=From:To:Cc:In-Reply-To:Subject:Date:Message-ID:MIME-Version: Content-Type:References; b=akFNHKEVhmkXxGxJiGl3A4d5SJPTme0eET9rJDA9o0o8PutXcydV8GX6RORZwt+KJ5H1FM2rlk8JrYnH+6PREMewh8RDxD5pGzJwOhI4lE9jbJVHlZtgOBkdqx5N/hqpmurNM+h72M7kW+Aa9iGAFqhgutRgdA73KDuut89FGAI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com; spf=pass smtp.mailfrom=samsung.com; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b=d/LlbNsg; arc=none smtp.client-ip=203.254.224.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=samsung.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b="d/LlbNsg" Received: from epcas5p3.samsung.com (unknown [182.195.41.41]) by mailout4.samsung.com (KnoxPortal) with ESMTP id 20241223021431epoutp040180aba203e5c6bab504281ecc78fbdd~TrJzvUoLP2608926089epoutp04L for ; Mon, 23 Dec 2024 02:14:31 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout4.samsung.com 20241223021431epoutp040180aba203e5c6bab504281ecc78fbdd~TrJzvUoLP2608926089epoutp04L DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1734920071; bh=c4mdwcxcN7uUzUqzZPO+90GO9wIv3nNZkWJW+auXCrM=; h=From:To:Cc:In-Reply-To:Subject:Date:References:From; b=d/LlbNsgkOsKpclUb9gU6E0umMpJQwAcYh3FVe0XmtPt8IqYat8GloFA0UHKE7GtN 20/fbHF+dSHkFfOmbLjDnsvCubVtpKzD1uSnz5hCpdWRzUTx0YBeFpv6JF6z9x5Sbm WQgNNqDvCTE09WW1HxXKlIBq/WRWoPCSeOfFAkic= Received: from epsnrtp1.localdomain (unknown [182.195.42.162]) by epcas5p4.samsung.com (KnoxPortal) with ESMTP id 20241223021430epcas5p4f01f78be3f9b7f45e6fc4fc18d3e6a2a~TrJzQ6CBV1821118211epcas5p4B; Mon, 23 Dec 2024 02:14:30 +0000 (GMT) Received: from epsmgec5p1new.samsung.com (unknown [182.195.38.175]) by epsnrtp1.localdomain (Postfix) with ESMTP id 4YGhRT1TcMz4x9Ps; Mon, 23 Dec 2024 02:14:29 +0000 (GMT) Received: from epcas5p3.samsung.com ( [182.195.41.41]) by epsmgec5p1new.samsung.com (Symantec Messaging Gateway) with SMTP id 6A.A3.19710.587C8676; Mon, 23 Dec 2024 11:14:29 +0900 (KST) Received: from epsmtrp2.samsung.com (unknown [182.195.40.14]) by epcas5p1.samsung.com (KnoxPortal) with ESMTPA id 20241223021428epcas5p17e96085071f7689ec40c6652851bad14~TrJw5jPen2138121381epcas5p1q; Mon, 23 Dec 2024 02:14:28 +0000 (GMT) Received: from epsmgms1p1new.samsung.com (unknown [182.195.42.41]) by epsmtrp2.samsung.com (KnoxPortal) with ESMTP id 20241223021428epsmtrp20e71dbb5cf8709a499e8096234cc234e~TrJw4uubj2534425344epsmtrp2a; Mon, 23 Dec 2024 02:14:28 +0000 (GMT) X-AuditID: b6c32a44-363dc70000004cfe-20-6768c785960c Received: from epsmtip1.samsung.com ( [182.195.34.30]) by epsmgms1p1new.samsung.com (Symantec Messaging Gateway) with SMTP id E4.03.18729.487C8676; Mon, 23 Dec 2024 11:14:28 +0900 (KST) Received: from INBRO001561 (unknown [107.122.12.6]) by epsmtip1.samsung.com (KnoxPortal) with ESMTPA id 20241223021426epsmtip135406ff4f99231bc31d063db717f2f2a~TrJvE8idA0113001130epsmtip1U; Mon, 23 Dec 2024 02:14:26 +0000 (GMT) From: "Pankaj Dubey" To: "'Rob Herring \(Arm\)'" , "'Lee Jones'" , "'Arnd Bergmann'" , "'Heiko Stuebner'" , "'Liviu Dudau'" , "'Sudeep Holla'" , "'Lorenzo Pieralisi'" Cc: "'Peter Griffin'" , "'Will McVicker'" , "'John Madieu'" , "'Krzysztof Kozlowski'" , , In-Reply-To: <20241217-syscon-fixes-v2-1-4f56d750541d@kernel.org> Subject: RE: [PATCH v2 1/3] mfd: syscon: Fix race in device_node_get_regmap() Date: Mon, 23 Dec 2024 07:44:25 +0530 Message-ID: <000201db54e0$64f8dc40$2eea94c0$@samsung.com> 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-Mailer: Microsoft Outlook 16.0 Thread-Index: AQEZrw4XBTjqISieS499QzyO27eqOgIlhVXbAn6f76O0UUFZUA== Content-Language: en-us X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrNJsWRmVeSWpSXmKPExsWy7bCmpm7r8Yx0g48vOSz+TjrGbvH/0WtW izUb6yz2vt7KbrGjbSGLxabH11gtLu+aw2ZxYGk7i0XLnxYWiw0z/rFY/N+zg91i+akdLBar Pv1ndOD1WDNvDaPH71+TGD1WvpjN7rFgU6nHplWdbB53ru1h89i8pN5j+7V5zB6fN8kFcEZl 22SkJqakFimk5iXnp2TmpdsqeQfHO8ebmhkY6hpaWpgrKeQl5qbaKrn4BOi6ZeYAXa2kUJaY UwoUCkgsLlbSt7Mpyi8tSVXIyC8usVVKLUjJKTAp0CtOzC0uzUvXy0stsTI0MDAyBSpMyM6Y e3E/e8Fn3oonbbPZGhjfcHcxcnJICJhIrF3zlKWLkYtDSGA3o8SM/euYIJxPjBKfn65nhXC+ MUr0PpnDDNPy++B6NojEXkaJF7dfskM4Lxgl1hzrAatiE9CXOPdjHli7iMBsJonflyeDOcwC 05gkDm5fyApSxSngKPHx1lomEFtYwF/i6KOzYN0sAqoSW5suMYLYvAKWEo/enmGHsAUlTs58 wgJiMwtoSyxb+BrqJgWJn0+Xgc0UEXCS6H3ZzAhRIy7x8ugRsPMkBO5wSHS2bmWDaHCRuPLw PhOELSzx6vgWdghbSuLzu71ANRxAto/E0t0eEOESiQ09S1kgbHuJA1fmsICUMAtoSqzfpQ+x ik+i9/cTJohOXomONiGIajWJ78/PQF0pI/GweSnUUg+J//v2s09gVJyF5LFZSB6bheSBWQjL FjCyrGKUTC0ozk1PTTYtMMxLLYfHeHJ+7iZGcKrWctnBeGP+P71DjEwcjIcYJTiYlUR4eeRS 04V4UxIrq1KL8uOLSnNSiw8xmgJDeyKzlGhyPjBb5JXEG5pYGpiYmZmZWBqbGSqJ875unZsi JJCeWJKanZpakFoE08fEwSnVwPRgdtu/nvn/mx2z7I0ufd7YsXqai23Atl3h6mVfunLE71Xu +9B046+Ld2eslk/rgYjjTx1t58+xWLC8/BWn1lmxXWzyH/bHbZQ657dMe7l77yd/2ZBE8beJ U5pF50qybVk+V2OlQ8bHhR2PHLdq1XxuM32u4Dpxm/KUVcGl4ouKPK/1L5u7tuHtb5ZuAxZZ Ad/32cHnrR0/cNvsvLVm7rHDWTuKAh1i7v8W7v33btHnz3rNxyxfybLwr3/2anuqVdifqnVv njzgmarPybz4mwXf9Z3T9lW7Pp3Xc/KVzJ7T1uYeAZXqRzxMAu74vrzlt3+l9GbFdXcczf60 uk44Jvllp+wiTZE4vXUGIsHnv2YosRRnJBpqMRcVJwIApq9oF14EAAA= X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrKIsWRmVeSWpSXmKPExsWy7bCSnG7L8Yx0g+lvRC3+TjrGbvH/0WtW izUb6yz2vt7KbrGjbSGLxabH11gtLu+aw2ZxYGk7i0XLnxYWiw0z/rFY/N+zg91i+akdLBar Pv1ndOD1WDNvDaPH71+TGD1WvpjN7rFgU6nHplWdbB53ru1h89i8pN5j+7V5zB6fN8kFcEZx 2aSk5mSWpRbp2yVwZezpW8BScIq34saJDpYGxoPcXYycHBICJhK/D65n62Lk4hAS2M0oMX3q OlaIhIzE5NUroGxhiZX/nrNDFD1jlLh38xZYgk1AX+Lcj3msIAkRgYVMEm9OzAdzmAVmMUl8 37KWFaLlOKPExN+7GUFaOAUcJT7eWssEYgsL+ErcezyBBcRmEVCV2Np0CayGV8BS4tHbM+wQ tqDEyZlPwGqYBbQlnt58CmcvW/iaGeI+BYmfT5eBnSQi4CTR+7KZEaJGXOLl0SPsExiFZyEZ NQvJqFlIRs1C0rKAkWUVo2RqQXFuem6xYYFhXmq5XnFibnFpXrpecn7uJkZwzGpp7mDcvuqD 3iFGJg7GQ4wSHMxKIrw8cqnpQrwpiZVVqUX58UWlOanFhxilOViUxHnFX/SmCAmkJ5akZqem FqQWwWSZODilGpgWn4pN5XmTfsj8oCGz8Yf7/+d9vHqoYr21WfS/d5rd6q3f7T5IrXDdsGDW IqPn7udYo1n3+x2PmVE6P2Jpv+LCvfNaxC4EXDtwcp7+qy3HOP4y7/r6QCiMJf8uU8QeFr9Q kb/7uZW9WD38jvktE1L+0eCTxfA982zk7/UZjH92rC6KtZ2pzL4uvzb0TtHDQ44ZkSuErU/n H36mx/jnVr297tzF3b/X3FRYvc/i4uYu8UUvqiZEbfzGemvCpwfFHFMfcPrrfXm7TTXpbs1t nRgXSxcm80/HxWfY8pfU1Rx+5Zlp7cc5u0PLiCN1Rbf9OZ3nm2/sypRfsWu7cjHr7o4H1Rsz hZnifk1y8y6zMT2nxFKckWioxVxUnAgAts/XJ0gDAAA= X-CMS-MailID: 20241223021428epcas5p17e96085071f7689ec40c6652851bad14 X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" CMS-TYPE: 105P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20241217181202epcas5p3dfeeea922cd1a71840ac126ddf20c644 References: <20241217-syscon-fixes-v2-0-4f56d750541d@kernel.org> <20241217-syscon-fixes-v2-1-4f56d750541d@kernel.org> > -----Original Message----- > From: Rob Herring (Arm) > Sent: Tuesday, December 17, 2024 11:42 PM > To: Lee Jones ; Arnd Bergmann ; Pankaj > Dubey ; Heiko Stuebner ; > Liviu Dudau ; Sudeep Holla ; > Lorenzo Pieralisi > Cc: Peter Griffin ; Will McVicker > ; John Madieu ; > Krzysztof Kozlowski ; linux- > kernel=40vger.kernel.org; linux-arm-kernel=40lists.infradead.org > Subject: =5BPATCH v2 1/3=5D mfd: syscon: Fix race in device_node_get_regm= ap() >=20 > It is possible for multiple, simultaneous callers calling > device_node_get_regmap() with the same node to fail to find an entry in t= he > syscon_list. There is a period of time while the first caller is calling > of_syscon_register() that subsequent callers also fail to find an entry i= n the > syscon_list and then call of_syscon_register() a second time. >=20 > Fix this by keeping the lock held until after of_syscon_register() comple= tes and > adds the node to syscon_list. Convert the spinlock to a mutex as many of = the > functions called in of_syscon_register() such as > kzalloc() and of_clk_get() may sleep. >=20 > Fixes: bdb0066df96e (=22mfd: syscon: Decouple syscon interface from platf= orm > devices=22) > Reviewed-by: Krzysztof Kozlowski > Tested-by: Krzysztof Kozlowski > Signed-off-by: Rob Herring (Arm) > --- Reviewed-by: Pankaj Dubey