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Mon, 23 Dec 2024 02:11:11 +0000 (GMT) Received: from epsmgmcp1.samsung.com (unknown [182.195.42.82]) by epsmtrp1.samsung.com (KnoxPortal) with ESMTP id 20241223021111epsmtrp15bb1429cb6cea8730ddb151eada5c801~TrG5J1lUw1551215512epsmtrp1P; Mon, 23 Dec 2024 02:11:11 +0000 (GMT) X-AuditID: b6c32a4b-fe9f470000004df4-71-6768c6bf9c1f Received: from epsmtip2.samsung.com ( [182.195.34.31]) by epsmgmcp1.samsung.com (Symantec Messaging Gateway) with SMTP id 00.B0.33707.EB6C8676; Mon, 23 Dec 2024 11:11:11 +0900 (KST) Received: from INBRO001561 (unknown [107.122.12.6]) by epsmtip2.samsung.com (KnoxPortal) with ESMTPA id 20241223021109epsmtip2288959e1d86621ed67ae589f52c7aed4~TrG3VuOQC1881118811epsmtip25; Mon, 23 Dec 2024 02:11:09 +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 07:41:07 +0530 Message-ID: <000001db54df$ef602f60$ce208e20$@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: AQEZrw4XBTjqISieS499QzyO27eqOgIlhVXbAn6f76O0UT+aQA== Content-Language: en-us X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrBJsWRmVeSWpSXmKPExsWy7bCmhu7+YxnpBrOe6Fr8nXSM3eL/o9es Fms21lnsfb2V3WJH20IWi02Pr7FaXN41h83iwNJ2FouWPy0sFhtm/GOx+L9nB7vF8lM7WCxW ffrP6MDrsWbeGkaP378mMXqsfDGb3WPBplKPTas62TzuXNvD5rF5Sb3H9mvzmD0+b5IL4IzK tslITUxJLVJIzUvOT8nMS7dV8g6Od443NTMw1DW0tDBXUshLzE21VXLxCdB1y8wBulpJoSwx pxQoFJBYXKykb2dTlF9akqqQkV9cYquUWpCSU2BSoFecmFtcmpeul5daYmVoYGBkClSYkJ3R unIjc8Fqvorbp/4wNzBO5eli5OSQEDCRuPnmJ2MXIxeHkMBuRomPXWuhnE+MElN+fmaCc9re LmPuYuQAa5n+pQYivpNR4vTjg6wgo4QEXjBKHNlTAGKzCehLnPsxjxWkSERgNpPE78uTwRxm gWlMEge3LwTr4BRwlPh4ay0TiC0s4C9x9NFZsA0sAqoSZ05UgIR5BSwlXv3fyA5hC0qcnPmE BcRmFtCWWLbwNTPEDwoSP58uAxspIuAkce5xAzNEjbjEy6NH2EH2Sgjc4JDYt7yPDaLBReLB y+nsELawxKvjW6BsKYmX/W3sEF/6SCzd7QERLpHY0LOUBcK2lzhwZQ4LSAmzgKbE+l36EKv4 JHp/P2GC6OSV6GgTgqhWk/j+/AzUlTISD5uXMkHYHhL/9+1nn8CoOAvJY7OQPDYLyQOzEJYt YGRZxSiZWlCcm55abFpgnJdaDo/u5PzcTYzgJK3lvYPx0YMPeocYmTgYDzFKcDArifDyyKWm C/GmJFZWpRblxxeV5qQWH2I0BQb2RGYp0eR8YJ7IK4k3NLE0MDEzMzOxNDYzVBLnfd06N0VI ID2xJDU7NbUgtQimj4mDU6qBaZ9oT5I/w1LBq/M7Vkda5DWkuMQ+W+Z5xvzuu0vf7iiKlgXO t0sPS3dbMfMJd0bL87W7nO58Z1oWbWh6V/a4xP5jpyyqBHcyr+m7c6Q7Nv6aQcSRxXe2nj5x 3CvkfR6XyeEtZ0+mdMft22KhxRdwau6Gx0XZISn8N/ftWVHpp9zy801cuZMif2hBblpd4bNN kYURMieUFHL1Yy2Zf96s02RoMI+Z3dH7dcMM02qOkPWMAbwzFZYIL3w6dc083WRp6bSpz1+Z r7s08fF8IU3lD0bpR5yy77wV0dafs1Kz2FdGMuDNvvs6ri9vpHCoBK/ge3Tj+AZlu79fQ7N8 NA9nNa1f+PB3/batJ0oyFglHK7EUZyQaajEXFScCAJtZ1W5bBAAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrPIsWRmVeSWpSXmKPExsWy7bCSvO7+YxnpBnu2MVv8nXSM3eL/o9es Fms21lnsfb2V3WJH20IWi02Pr7FaXN41h83iwNJ2FouWPy0sFhtm/GOx+L9nB7vF8lM7WCxW ffrP6MDrsWbeGkaP378mMXqsfDGb3WPBplKPTas62TzuXNvD5rF5Sb3H9mvzmD0+b5IL4Izi sklJzcksSy3St0vgypj25CF7QRNfxcMHO5gbGF9xdzFycEgImEhM/1LTxcjFISSwnVGid8cS 5i5GTqC4jMTk1StYIWxhiZX/nrNDFD1jlFh34QkLSIJNQF/i3I95rCAJEYGFTBJvTswHc5gF ZjFJfN+ylhWi5TijxMTfuxlBWjgFHCU+3lrLBGILC/hK3Hs8gQXkDhYBVYkzJypAwrwClhKv /m9kh7AFJU7OhNjGLKAt8fTmUzh72cLXUKcqSPx8ugzsVBEBJ4lzjxuYIWrEJV4ePcI+gVF4 FpJRs5CMmoVk1CwkLQsYWVYxiqYWFOem5yYXGOoVJ+YWl+al6yXn525iBMepVtAOxmXr/+od YmTiYDzEKMHBrCTCyyOXmi7Em5JYWZValB9fVJqTWnyIUZqDRUmcVzmnM0VIID2xJDU7NbUg tQgmy8TBKdXAtNLt2accU6/Yu6G+v2bZznRkf//wiYejYbzJy/WSTkb3FsTnnhTW6bF+vuPP g7LPOhrdM1+rfDrf+ju0yvm9LKPKYq36uR3bLV9tLJW4x3h1YtBX56P6hfvfMJ6qVV2SyP28 56fpY/4m39BKFb3O/1x7nijHim6zYjwbc1KxbZtOSuydwLveGTsdgoS+eR9udPHZ+0hFMbnv yO1Lh4ydK5VyHQVybk/8LJfhyvzSZZ94hBTf3uCH6ZvSjk7bpW9btDXmw4F1EfcimnhPmGdv f1Ten8Ykm+l/f/rNs7uUv8Q9fDWfpXBnzozNqenXJL0mP7WVORDMJ9gk0lGZwaM1e45qYtwq lnVi7n8OmxQqsRRnJBpqMRcVJwIAwQiJpkIDAAA= X-CMS-MailID: 20241223021111epcas5p148011ea277570c5090bada9d06a24575 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) > --- Tested on arm64: Tesla FSD=20 Tested-by: Pankaj Dubey Thanks. Pankaj Dubey