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 B58A8C43458 for ; Fri, 10 Jul 2026 12:57:57 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8CD6C6B0088; Fri, 10 Jul 2026 08:57:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 87F916B008A; Fri, 10 Jul 2026 08:57:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 76DF36B008C; Fri, 10 Jul 2026 08:57:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 522046B0088 for ; Fri, 10 Jul 2026 08:57:56 -0400 (EDT) Received: from smtpin09.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay08.hostedemail.com (Postfix) with ESMTP id A7CFD140417 for ; Fri, 10 Jul 2026 12:57:55 +0000 (UTC) X-FDA: 84972869310.09.81B822D Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf30.hostedemail.com (Postfix) with ESMTP id 25B1280002 for ; Fri, 10 Jul 2026 12:57:54 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=LZynFH0m; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf30.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1783688274; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=GJ+ZZjoXshQwp4HjCw3hwahYLU+lQJ/F/RXGt07TIgQ=; b=VeX6zjJsAEvX/uAOgUxcZ0KT8O/bsjf9OwfyfPTbwnEGzFJzGZdyj+XivksxOsWij/Q5L+ nH4Qi5B6/QnigIQEndK+Wep1DPsfz6CB37IfUZUuGssQWRG2okUKynHDOm9f+6vQKJONDq UsFU3WZweQ76Ou48dLsAgMl0+N1UHkA= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=LZynFH0m; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf30.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1783688274; b=AOE4Zmn4X8E5NaOuBG+RWt6yZ/Sdjkjl1YAcY0kztWCBLT26UM/OF1wEEIsF99xgHyJmfx YjN0b2usJQZfoP/TdTA41u6VNnQxZYCttDTlZxcwQ2XXFVMRl3Dw90am0jN4w6i1OEKIQ5 HNAPLewtgBkAI1WntCnW0xTN48UlRrw= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 8BB2560052; Fri, 10 Jul 2026 12:57:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 400BA1F000E9; Fri, 10 Jul 2026 12:57:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783688273; bh=GJ+ZZjoXshQwp4HjCw3hwahYLU+lQJ/F/RXGt07TIgQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=LZynFH0m2Au0GulWeBOL9Se7/aaURATREjA+Ms9gJ6cf6EtMIjnSwTCzlx6N02XnT dmeQJC81rdCvri3euXeoAfSFGRC9CIcPElPxCiLeWREStZCOdOcBu/+qjU0yCmT0QP enmkG7dOtBv4nDyzVsVDneapP70gJ5rRL8UmcRvS6VjvhQn6RB008l2MD2l32xfGXG 5cYGi71NQAngfXSfymfzcPQ2MPJVVaecPUhTIsgTQH82cuEl6S9WmxjFwNuGAgHhNP P2e2TfAIlREWpipjFo8pinavN75nYQAV2KudNOomqBE4nuw3/+drShM6jwi7qLxDtZ ksyTR9LLiW0jQ== Date: Fri, 10 Jul 2026 13:57:40 +0100 From: Lorenzo Stoakes To: Andrew Morton , Suren Baghdasaryan , "Liam R. Howlett" , Vlastimil Babka , Shakeel Butt , David Hildenbrand , Mike Rapoport , Michal Hocko , Uladzislau Rezki , Toshi Kani , Catalin Marinas , Will Deacon Cc: David Carlier , Dev Jain , Ryan Roberts , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, stable@vger.kernel.org, syzbot+fd95a72470f5a44e464c@syzkaller.appspotmail.com Subject: Re: [PATCH 1/2] mm/vmalloc: acquire init_mm read lock on huge vmap promotion Message-ID: References: <20260710-series-vmap-race-fix-v1-0-5b3794c113fe@kernel.org> <20260710-series-vmap-race-fix-v1-1-5b3794c113fe@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260710-series-vmap-race-fix-v1-1-5b3794c113fe@kernel.org> X-Stat-Signature: k44rg7yz3qzi3okshzs6fg4ddip7enpj X-Rspamd-Queue-Id: 25B1280002 X-Rspamd-Server: rspam01 X-Rspam-User: X-HE-Tag: 1783688273-77719 X-HE-Meta: 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 xuqZwckx Txrxt+ZGofkD5OQgfGRZbqzWyIG8jjM7sfoLLsfd3vNhMWMd63cuOWTPCnSFEnA6OuXFJDrwVKOLAgjhfnpv71gO0La5b62bb+gK8NiN6b03zm4CI/Ft0Rgbe8MgbCHNcgdErL6jOhbhBSVXDotVWCZ+Ab0N765UVMPxF4eJORe9eZtuGvYCWgGNy+Aqb/WgvGYliEghsMeuPeb90yUGhLhQmUWp9kcHWLuyJqbwOQHw3rRy4lD5EUGk94CxbssEGjeghu47C1XUa2lCnqjT35PilzjVhsS/zF57Cnp//ok7JSl2VewhzMXsN7R2b/9lsTmVNDX0HvsmT72M3qg4MJwXMGC2G2XuTinIPK1sfrjEEU04AyPKg6+hCrRrMUynfVdCx16BZqxAE4mPAAcXq7bwLt0EqHX6n6xrQTsuCyCQo6ok9mnwDsmOsQiqbFxMrt5PedG97S8IWJt0= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: As per Sashiko, we need to account for x86's slightly bat... interesting ptdump of non-init_mm page tables. The fix is to take a nested init_mm lock in ptdump_walk_pgd(), which is safe as nothing depends on an init_mm lock prior to acquiring an arbitrary mm's lock. I think this could potentially be sent as an entirely separate patch, as it doesn't change what this protects against, nor the x86 CPA patch, both of which stand on their own. Cheers, Lorenzo