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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 74CA5CFD2F6 for ; Thu, 27 Nov 2025 19:17:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=liiFe93kfLrBacbbNxwJ9Yv1B3wH4KJGG8Fcmqlv9bE=; b=gQhu7DuctTjGIMA2CJmC2u/a8e hcg1lwVI6NERT6TMbDM0Wv8kfRB1jGae7lwMXsFHq/XyLkwxs0YHjIQ0noLO9/miNHC90EWJKhgj8 FjZO5vH7sw2GHZAZe3U+0/BFZ4zdc+67uxzMfKieyrXYmdBrEwEVa2ZjZu26wDf3K83i72rThxB5p B3gqWBln2SSj3cvjY3rGfkE1JpEiWzJdI9mdpMUc2q0Pc85lqydrhmO+osWOaOnUQ9Cw97bbfkUe0 5EpLuSj9ka8QVseVtWclYYon4+3W7ALihFN04PKkG04vcyEzFsmd5dbTbeiw41ugQBVNPl9YZLSG4 KqZUwjoQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vOhUJ-0000000H7tS-0Slq; Thu, 27 Nov 2025 19:17:07 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vOhUI-0000000H7su-0L1z for linux-arm-kernel@lists.infradead.org; Thu, 27 Nov 2025 19:17:06 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 39BAE60213; Thu, 27 Nov 2025 19:17:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DCE02C4CEF8; Thu, 27 Nov 2025 19:17:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764271024; bh=CTaIZx3TPTCQU7Qtrk2ZVlkt8DjltysBLZiTjEs9JMo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kyGMlqmRtQRpAhsOwTQrcFlvE9aVtX0vRUPOxb0rotwnUnQmlHHZIrz3jdrSGssaB kRbmCfTuwRO/TNRjg3IrSM2Pw12jpwt7HVCso7ZQVDiXbB/3TDBKyb/lPWMbyvr75k CQCekPexBl0eSQfinzb7UPDsL3QZOrqMGVMjaLb9DSY4be1RhRSppR+DMgeqwBey3P VOLYIAhEnBVSdLvHfOar2r1NE33tP9LurfK82ItVHBCebqK3+tRpXuK5HbufNl1Rzw UXbyz5O6iUO/nHaa3J693nNGfySyzjl8kvXsZU5+hekeR/H1N1FBx1v9RFXUiKQXT1 2z4WCndmrs92Q== Date: Thu, 27 Nov 2025 11:17:04 -0800 From: Kees Cook To: Ryan Roberts Cc: Ard Biesheuvel , Will Deacon , Arnd Bergmann , Jeremy Linton , Catalin Marinas , Mark Rutland , "linux-arm-kernel@lists.infradead.org" , Linux Kernel Mailing List Subject: Re: [DISCUSSION] kstack offset randomization: bugs and performance Message-ID: <202511271111.A9BC57E2C@keescook> References: <202511241250.EB2ADED@keescook> <202511262358.1B99951@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Nov 27, 2025 at 02:09:04PM +0000, Ryan Roberts wrote: > no: rip out kstack offset randomization Uh, no. There are system builders that have no problem with the current performance. The _feature_ must stay because it has users. Whether it is default-enabled, etc, sure, I have no problem with making changes there. Whatever we can do to make it better, I obviously welcome, but we can't remove it. -- Kees Cook