From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4C04ED11183 for ; Thu, 27 Nov 2025 11:21:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AC2706B0012; Thu, 27 Nov 2025 06:21:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A99ED6B0022; Thu, 27 Nov 2025 06:21:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9D6EE6B002F; Thu, 27 Nov 2025 06:21:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 8D1856B0012 for ; Thu, 27 Nov 2025 06:21:18 -0500 (EST) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 566765BD95 for ; Thu, 27 Nov 2025 11:21:18 +0000 (UTC) X-FDA: 84156145836.05.A426AE9 Received: from canpmsgout10.his.huawei.com (canpmsgout10.his.huawei.com [113.46.200.225]) by imf15.hostedemail.com (Postfix) with ESMTP id 2F102A0003 for ; Thu, 27 Nov 2025 11:21:14 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=huawei.com header.s=dkim header.b=kzAHUMF2; spf=pass (imf15.hostedemail.com: domain of xieyuanbin1@huawei.com designates 113.46.200.225 as permitted sender) smtp.mailfrom=xieyuanbin1@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1764242476; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=DodGNQ4J3R60otr7WXzwptpN2trZwaXPd+16aznDXKU=; b=QHOv1UP1HCuJyrLQpcm0/SDKWVqcJ1BpmD4FQExkWVdwkFUAdG2c90UHqqTPRcfRMedxwI dHDWsoPRwKxUx9pBvVAra/XoTpcIL6EzzX6lOKIGFT7gmh2xei9u1YGnXXP4q0h3Kc4SnI MEHPZf8J6m2gxfB0Y9WicHuNiCUIZFo= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=huawei.com header.s=dkim header.b=kzAHUMF2; spf=pass (imf15.hostedemail.com: domain of xieyuanbin1@huawei.com designates 113.46.200.225 as permitted sender) smtp.mailfrom=xieyuanbin1@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1764242476; a=rsa-sha256; cv=none; b=MQQ/L5YGVg8VsO9eLi84z9FoK9+5ccVQLb07z8md+8MTdaovqPYMbTA60W+1YbBaSU32K1 ChlkU5/LWvEqYkymLbcuC6IA7WY31q5/DP9tW5/51TnaU3adq7PePpTrfK3XCOmO8/8faP ovQ/wmCDCoxjz/y8gNqDGFnNEtRDA9s= dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=DodGNQ4J3R60otr7WXzwptpN2trZwaXPd+16aznDXKU=; b=kzAHUMF2dUX/75F2x8k4f67X3bwt94v+LeKbd6y1I+Pfnt/W9chF7FpLBH1NgTjP/L/NGfo8n xvIQ0+PuPafeVGbUpzBFi9IJnhCxY1y3YnVnFQlCNNtgM7nYb04k1porCfASxHwGKtjxPIckwVs 1urT6Cq6FxhqN1lH2J74Qto= Received: from mail.maildlp.com (unknown [172.19.162.112]) by canpmsgout10.his.huawei.com (SkyGuard) with ESMTPS id 4dHDTl6J2qz1K96R; Thu, 27 Nov 2025 19:19:23 +0800 (CST) Received: from kwepemj100009.china.huawei.com (unknown [7.202.194.3]) by mail.maildlp.com (Postfix) with ESMTPS id CD7A614011F; Thu, 27 Nov 2025 19:21:10 +0800 (CST) Received: from DESKTOP-A37P9LK.huawei.com (10.67.109.17) by kwepemj100009.china.huawei.com (7.202.194.3) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Thu, 27 Nov 2025 19:21:09 +0800 From: Xie Yuanbin To: , , , , , CC: , , , , , , , , , , , , , , , , , , , , , , , , , , Xie Yuanbin Subject: Re: [RFC PATCH] vfs: Fix might sleep in load_unaligned_zeropad() with rcu read lock held Date: Thu, 27 Nov 2025 19:20:35 +0800 Message-ID: <20251127112035.129014-1-xieyuanbin1@huawei.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251127072057.EbvhUyG4@linutronix.de> References: <20251127072057.EbvhUyG4@linutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.67.109.17] X-ClientProxiedBy: kwepems500001.china.huawei.com (7.221.188.70) To kwepemj100009.china.huawei.com (7.202.194.3) X-Rspamd-Queue-Id: 2F102A0003 X-Rspamd-Server: rspam02 X-Stat-Signature: k7j16jp1gbfhgqxysj8fpfqbnwwh3x7f X-Rspam-User: X-HE-Tag: 1764242474-976487 X-HE-Meta: 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 6hoFoEdM 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On, Thu, 27 Nov 2025 08:20:57 +0100, Sebastian Andrzej Siewior wrote: > This all should be covered by the series here > https://lore.kernel.org/all/20251110145555.2555055-1-bigeasy@linutronix.de/ Yes, I know it. > or do I miss something. We had some discussions about this bug: Link: https://lore.kernel.org/lkml/20251126090505.3057219-1-wozizhi@huaweicloud.com/ The discussions: Link: https://lore.kernel.org/CAHk-=wh1Wfwt9OFB4AfBbjyeu4JVZuSWQ4A8OoT3W6x9btddfw@mail.gmail.com Link: https://lore.kernel.org/20251126192640.GD3538@ZenIV Link: https://lore.kernel.org/aSeNtFxD1WRjFaiR@shell.armlinux.org.uk According to the discussion, in do_page_fault(), when addr >= TASK_SIZE, we should not try to acquire the mm read lock or find vma. Instead, we should directly call __do_kernel_fault() or __do_user_fault(). Your submission just moved harden_branch_predictor() forward. I think we can have more discussions about the patches to fix the missing spectre. I am trying to write a new patch, I hope it will better handle these two bugs and be compatible with PREEMPT_RT scenarios. > Sebastian Thanks! Xie Yuanbin