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 318EBEB2703 for ; Tue, 10 Feb 2026 19:28:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 71F186B0089; Tue, 10 Feb 2026 14:28:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 700726B008A; Tue, 10 Feb 2026 14:28:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6209E6B008C; Tue, 10 Feb 2026 14:28:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 512DE6B0089 for ; Tue, 10 Feb 2026 14:28:15 -0500 (EST) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id E6677C2476 for ; Tue, 10 Feb 2026 19:28:14 +0000 (UTC) X-FDA: 84429532908.03.9087133 Received: from mail-wm1-f41.google.com (mail-wm1-f41.google.com [209.85.128.41]) by imf25.hostedemail.com (Postfix) with ESMTP id E96BCA000F for ; Tue, 10 Feb 2026 19:28:12 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=JzoAX4C4; spf=pass (imf25.hostedemail.com: domain of gorcunov@gmail.com designates 209.85.128.41 as permitted sender) smtp.mailfrom=gorcunov@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1770751693; 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=LFyGR2DyLRU+91jbuLD+/fzhLRHaNo946KYs1mYXfdg=; b=X9Pcs2fzcW5DUs/CmjxAxHKqYUchQ4wtl5NLMgBIIt8LNiPEV5PLK9cpBKthKN+aZStUxb NssG1Lqz3rheJeBelBHj/MlTHlQugi8snDApDw3PM5QchI85SvVSydzkZUuob7gd0/RAbH PQnLz4TLbYwlv2kaCH4f05IslH4f13Y= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=JzoAX4C4; spf=pass (imf25.hostedemail.com: domain of gorcunov@gmail.com designates 209.85.128.41 as permitted sender) smtp.mailfrom=gorcunov@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1770751693; a=rsa-sha256; cv=none; b=nDQGo67ZBgu4H8w6ysf5DJRPOge7eFGlO1uiTZaJs8875vXVpIBKwFaT6OIU85bhtribzS hWqwtvxBeMFunPJJ6r7DTn1PLs2Wy8J9wdq+4cfJ6kTy90zgvvLerbgHGNMxdGZ36DoZAj 2j79pDqZg+a7X0BNY9VVXLHEuuDUqGo= Received: by mail-wm1-f41.google.com with SMTP id 5b1f17b1804b1-4801d7c72a5so36574755e9.0 for ; Tue, 10 Feb 2026 11:28:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1770751691; x=1771356491; darn=kvack.org; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=LFyGR2DyLRU+91jbuLD+/fzhLRHaNo946KYs1mYXfdg=; b=JzoAX4C4XyQmXVOFo382w5cDu/6NtczkkGf8PXzMBUR4SQmz3ajA243f606nxH0+Ny LaFyjLeaOGdO7IzE/+RYa7VtmgDh7dYogh8sxWIowtfJBsNsVe8uw0xYPxzzEwOXZ3aX 5qzp+8/PqgvKAaJpxuzmavoGfgLJxCm7mEvMo6A8hDmbxjPpn74AEub9Yh9o226D3uMz OP4Vxxd7mMx5uhuipdj/HMlVeFIe928h7a2UgWnE/Vz4z8WLE43f1SULpD4y/LrJd/Tr drdKAhWAEvhj1S5Y+biFXltQLiKTUad6HzWHMt4KomOEeeRQwolDDiXwXKZYu80mxSPs hVaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770751691; x=1771356491; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=LFyGR2DyLRU+91jbuLD+/fzhLRHaNo946KYs1mYXfdg=; b=WjXjYWqLOK24/2Q0aewFjBnxN4pkozW/quHyAatMCxmXT38pFT8FXrIzMDxD6oEgH5 ajfUr4FpBNysi3I0SC1Rd9op8xYtGhrLosXVU1T7S1+Dh3bwDnD3r3wqTMbCy1DzwTaw 9NRMO/OHHsoRpjBes1Ea7g/jLjLt5rb3XYwtFph4175pMRGkVBOrslomD7yRNIBvfKYC 6mY+53SNsn2lUImoIt8dkU/Rsoi28RGRqZqiQeGA7nLc/LSiTcjGtb3XHBdPfilAV9jA 9bVu1YXqPYfLUmByZxx1Na7QN3TKAov7/6cpiQY5ZlYZ5e1nkRhTaOKsHEpH1fnC3siY o3Tw== X-Forwarded-Encrypted: i=1; AJvYcCXsSeYIijkccLqgH3I+XkQFbo+/Jm24/mNv7ZZDqhIbCvirBwlTbK0R9Hh7XH3GYgDI9k+zN10K1g==@kvack.org X-Gm-Message-State: AOJu0YzW08MgWvvRFLUwdRnU3KMT4sUkQ0OvGP5NSTWU8sWiA8t6l8aB VsdEUM7Gb8O+HScX5B7NnrRgLb6JeoNNH9gTc1EvEV7EhY+GnAASR+FP X-Gm-Gg: AZuq6aIt24RL4z/g2RlDSdwUrD1/vkKQb+nAUpXkYtz3jCmFPOSZcV7IO1aEBOpUOWK bzMlCTK+sQsroJWXt1K6XjF3hER/HXxyR7bBNEMm1bCQ8YZHWpUkYdWnZyMu54SpEVnS0D0Xi6H s/k5fDemo2dhO5hXqkV92UvW4VVTQP6iP5mU4PdsdzLnNTDNRVFdy4TwDE5vE4/eiIPgOKIkwl6 FsUUBrdsSS4WVPyPPZB7NJSP8Sc5tV6lLtmXXPfbyTh260hEWo1E1dv1p781FnFQdLvx6WtVsww IuA8VEKlMUcNvzMfapAUyUQPo+j/0KtghPe1kLptEv5emndDnstTaLb75yQv2r5iOhelwjky5eU Wd2LgM93/3MyhlPMa8dqGNhJdYAwDfubfiy2DazDXE4+Rs4ToOXlEG15Bb6Qu9vpFpL39uSmOwg pC7vugKgUYQOalmpnNFj8o29Rc/ZE= X-Received: by 2002:a05:600c:470b:b0:477:7ae0:cd6e with SMTP id 5b1f17b1804b1-4835b8bbf77mr1193155e9.5.1770751691077; Tue, 10 Feb 2026 11:28:11 -0800 (PST) Received: from grain.localdomain ([212.46.38.55]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-436297462a8sm33795335f8f.30.2026.02.10.11.28.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 10 Feb 2026 11:28:10 -0800 (PST) Received: by grain.localdomain (Postfix, from userid 1000) id 8CBD35A004A; Tue, 10 Feb 2026 22:28:06 +0300 (MSK) Date: Tue, 10 Feb 2026 22:28:06 +0300 From: Cyrill Gorcunov To: Andrei Vagin Cc: Kees Cook , Andrew Morton , Mike Rapoport , Alexander Mikhalitsyn , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, criu@lists.linux.dev, Chen Ridong , Christian Brauner , David Hildenbrand , Eric Biederman , Lorenzo Stoakes , Michal Koutny Subject: Re: [PATCH 0/4 v3] exec: inherit HWCAPs from the parent process Message-ID: References: <20260209190605.1564597-1-avagin@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260209190605.1564597-1-avagin@google.com> User-Agent: Mutt/2.2.14 (2025-02-20) X-Stat-Signature: i5swb6xpt6owmhdxn5jremwarfhj3wwt X-Rspamd-Queue-Id: E96BCA000F X-Rspam-User: X-Rspamd-Server: rspam04 X-HE-Tag: 1770751692-508967 X-HE-Meta: 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 KEMCCB23 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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 Mon, Feb 09, 2026 at 07:06:01PM +0000, Andrei Vagin wrote: > This patch series introduces a mechanism to inherit hardware capabilities > (AT_HWCAP, AT_HWCAP2, etc.) from a parent process when they have been > modified via prctl. > > To support C/R operations (snapshots, live migration) in heterogeneous > clusters, we must ensure that processes utilize CPU features available > on all potential target nodes. To solve this, we need to advertise a > common feature set across the cluster. > > Initially, a cgroup-based approach was considered, but it was decided > that inheriting HWCAPs from a parent process that has set its own > auxiliary vector via prctl is a simpler and more flexible solution. > > This implementation adds a new mm flag MMF_USER_HWCAP, which is set when the > auxiliary vector is modified via prctl(PR_SET_MM_AUXV). When execve() is > called, if the current process has MMF_USER_HWCAP set, the HWCAP values are > extracted from the current auxiliary vector and inherited by the new process. > > The first patch fixes AUXV size calculation for ELF_HWCAP3 and ELF_HWCAP4 > in binfmt_elf_fdpic and updates AT_VECTOR_SIZE_BASE. > > The second patch implements the core inheritance logic in execve(). > > The third patch adds a selftest to verify that HWCAPs are correctly > inherited across execve(). > > v3: synchronize saved_auxv access with arg_lock > > v1: https://lkml.org/lkml/2025/12/5/65 > v2: https://lkml.org/lkml/2026/1/8/219 > > Cc: Andrew Morton > Cc: Chen Ridong > Cc: Christian Brauner > Cc: David Hildenbrand > Cc: Eric Biederman > Cc: Kees Cook > Cc: Lorenzo Stoakes > Cc: Michal Koutny > Cc: Cyrill Gorcunov Looks ok to me. Thanks, Andrei! Reviewed-by: Cyrill Gorcunov