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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10140C433F5 for ; Wed, 13 Oct 2021 16:51:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E93D961053 for ; Wed, 13 Oct 2021 16:51:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237406AbhJMQxf (ORCPT ); Wed, 13 Oct 2021 12:53:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:50300 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233731AbhJMQxb (ORCPT ); Wed, 13 Oct 2021 12:53:31 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D3CCB61168; Wed, 13 Oct 2021 16:51:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1634143887; bh=LBXct+kmDvk5TkVtHHW7PAuxFFNJuafSepYBdwCX45M=; h=In-Reply-To:References:Date:From:To:Cc:Subject:From; b=XUWkhdoYmoYJ1RszQRAvXM1laNkpz+L2dSEERb+eQOYg8SwjCZEIovM6rBWLWJ4lo wogVzszJFYyAnG1Wp5aZRrZ8O26ZoSJ0QkEnAaBv9zV51nZoE2dIQ8km8CkvhM5is1 u4r33jjRniHAqQLrpNbZg7NKSPq2psbNwzTpRgo8cYoiQ4DUek/fER6hLriDagshaQ YvPhGI2zI5zRQwlVt4PR69XnRphY1l9DUAtLHWYEsxm5zyaMYyc1TwxIs1yH1IfwtY u/IyDtuMuCfkPIaTw/gEOMAD88nU4qyYlmd6KmU/WLI910AdS/UDInJYzCq99p1ULr SWxYsS265cTBg== Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailauth.nyi.internal (Postfix) with ESMTP id E276D27C0054; Wed, 13 Oct 2021 12:51:25 -0400 (EDT) Received: from imap48 ([10.202.2.98]) by compute6.internal (MEProxy); Wed, 13 Oct 2021 12:51:25 -0400 X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvtddrvddutddguddtgecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd enucfjughrpefofgggkfgjfhffhffvufgtsehttdertderredtnecuhfhrohhmpedftehn ugihucfnuhhtohhmihhrshhkihdfuceolhhuthhosehkvghrnhgvlhdrohhrgheqnecugg ftrfgrthhtvghrnheptdfhheettddvtedvtedugfeuuefhtddugedvleevleefvdetleff gfefvdekgeefnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrh homheprghnugihodhmvghsmhhtphgruhhthhhpvghrshhonhgrlhhithihqdduudeiudek heeifedvqddvieefudeiiedtkedqlhhuthhopeepkhgvrhhnvghlrdhorhhgsehlihhnuh igrdhluhhtohdruhhs X-ME-Proxy: Received: by mailuser.nyi.internal (Postfix, from userid 501) id 6ED4221E006A; Wed, 13 Oct 2021 12:51:24 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.5.0-alpha0-1345-g8441cd7852-fm-20211006.001-g8441cd78 Mime-Version: 1.0 Message-Id: <98e38690-6be2-4839-99a4-148b61cc9749@www.fastmail.com> In-Reply-To: <20211013163023.GD8557@1wt.eu> References: <20211012222311.578581-1-ammar.faizi@students.amikom.ac.id> <20211013125142.GD5485@1wt.eu> <20211013140723.GE5485@1wt.eu> <20211013142433.GB8557@1wt.eu> <20211013163023.GD8557@1wt.eu> Date: Wed, 13 Oct 2021 09:51:04 -0700 From: "Andy Lutomirski" To: "Willy Tarreau" , "Michael Matz" Cc: "Borislav Petkov" , "Ammar Faizi" , "Paul Walmsley" , "Palmer Dabbelt" , "Albert Ou" , "Linux Kernel Mailing List" , "Thomas Gleixner" , "Ingo Molnar" , "the arch/x86 maintainers" , "H. Peter Anvin" Subject: Re: [PATCH] tools/nolibc: x86: Remove `r8`, `r9` and `r10` from the clobber list Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 13, 2021, at 9:30 AM, Willy Tarreau wrote: > Hello Michael, > > On Wed, Oct 13, 2021 at 04:24:28PM +0000, Michael Matz wrote: > (...) >> In short: Ammars initial claim: >> >> > Linux x86-64 syscall only clobbers rax, rcx and r11 (and "memory"). >> > >> > - rax for the return value. >> > - rcx to save the return address. >> > - r11 to save the rflags. >> > >> > Other registers are preserved. >> >> is accurate and I will clarify the psABI to make that explicit. > > Many thanks for this very detailed explanation! Ammar, I'll take your > patch. Acked-by: Andy Lutomirski > > Thanks all, > Willy