From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout11.his.huawei.com (frasgout11.his.huawei.com [14.137.139.23]) (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 55FE746521 for ; Tue, 23 Apr 2024 07:22:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=14.137.139.23 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713856977; cv=none; b=JZxbTRihDCu8+9RPZEktPGIASpkoMp8ed+V2xN75xdAFs+ovPTQdEO0r3j/CPqgEGxvJKbPPm6gcpBAUaukKbHQJzbRxukQt8n995EiJi2vnXQ0of84PucIDJF6jfwCCKukcyre5/PapFeOLzhwcGLz8VE++VIPyX2+vwcGR3qA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713856977; c=relaxed/simple; bh=L4OcFr6Wq5nOJsUOvDaAmjOCMS9WVXFUfLPu4Nn2G+0=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=USI7D5F46d9EC8qvN4CiYV2ZPBaMzW/nAlenaX/sbniEJxQSHMm1baLiLhbvYCOw37QXXHSge/EeBrlVph/XyjphbYQGmC+idtNTpIvKEDtLA+BWRgm4bWtEWCz2ZgaKK5ONPZFRLkauZdLH5Zukvf7/14yJ1EG71nb6iiv6/wo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=14.137.139.23 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.18.186.51]) by frasgout11.his.huawei.com (SkyGuard) with ESMTP id 4VNtSh53Lhz9v7g7 for ; Tue, 23 Apr 2024 15:06:12 +0800 (CST) Received: from mail02.huawei.com (unknown [7.182.16.47]) by mail.maildlp.com (Postfix) with ESMTP id AB0F01404A5 for ; Tue, 23 Apr 2024 15:22:42 +0800 (CST) Received: from [127.0.0.1] (unknown [10.204.63.22]) by APP1 (Coremail) with SMTP id LxC2BwA3LBW6YSdmcLXMBg--.38603S2; Tue, 23 Apr 2024 08:22:42 +0100 (CET) Message-ID: <15d5da65079d072856ef5e8d88040df2095bb6b7.camel@huaweicloud.com> Subject: Re: [PATCH] um: Add winch to winch_handlers before registering winch IRQ From: Roberto Sassu To: Johannes Berg , richard@nod.at, anton.ivanov@cambridgegreys.com Cc: linux-kernel@vger.kernel.org, linux-um@lists.infradead.org, Roberto Sassu Date: Tue, 23 Apr 2024 09:22:31 +0200 In-Reply-To: <1743ad022502d64042fa7db4d847a988bb90cbdc.camel@sipsolutions.net> References: <20240307104926.3531358-1-roberto.sassu@huaweicloud.com> <1743ad022502d64042fa7db4d847a988bb90cbdc.camel@sipsolutions.net> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.44.4-0ubuntu2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID:LxC2BwA3LBW6YSdmcLXMBg--.38603S2 X-Coremail-Antispam: 1UD129KBjvdXoWrtF4UKF47ur4rCryrJF43ZFb_yoW3JFgEgr 4vk34fG3yDJrs2krs0k34qvr4vga18Kr13JwsIqrW3X34DurZ3JrWSyr9Yvw15G3W5JFZx GrZIgF9agr17CjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbOkYFVCjjxCrM7AC8VAFwI0_Gr0_Xr1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwV A0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWUJVWUCwA2z4x0Y4vE2Ix0cI8IcVCY1x02 67AKxVWUJVW8JwA2z4x0Y4vEx4A2jsIE14v26r1j6r4UM28EF7xvwVC2z280aVCY1x0267 AKxVW8JVW8Jr1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2 j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7x kEbVWUJVW8JwACjcxG0xvEwIxGrwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWU JVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67 kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY 6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6rW3Jr0E3s1lIx AIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVWUJVW8JbIYCTnIWIev Ja73UjIFyTuYvjxUrR6zUUUUU X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAgACBF1jj5iypgABs4 On Thu, 2024-03-28 at 09:25 +0100, Johannes Berg wrote: > On Thu, 2024-03-07 at 11:49 +0100, Roberto Sassu wrote: > > From: Roberto Sassu > >=20 > > Registering a winch IRQ is racy, an interrupt may occur before the winc= h is > > added to the winch_handlers list. > >=20 > > If that happens, register_winch_irq() adds to that list a winch that is > > scheduled to be (or has already been) freed, causing a panic later in > > winch_cleanup(). > >=20 > > Avoid the race by adding the winch to the winch_handlers list before > > registering the IRQ, and rolling back if um_request_irq() fails. > >=20 >=20 > Reviewed-by: Johannes Berg Thank you! Richard, are you going to pick this up? Thanks Roberto