From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x2272xa7LDvwv1xfXRj0RJXoiEeHyHvEqHDeioq35hD9T7mSQk3bBm0jXIqpyc0pN1tSSfG2y ARC-Seal: i=1; a=rsa-sha256; t=1516902825; cv=none; d=google.com; s=arc-20160816; b=nDOb6n4Lmw5M6oXKeLsC9mmpGP6Bhi6a/3OPK5fWg7hnYXxXUGaNnE0RGR3+AIw7Nx mXbLuzjVva2S505zgFv3DFJoxr6nDweeqNk4QAzxNgbE1G5pAuVkWSoFLzO1k094qpjO O0uyiqOBirVoyZUQvCusiUzbUZPxRHCoGql46WgqUkUFfbeJqj/8L6iMpSgqdytYFzoi 3qF65QB7ilHmtO13FYvq0dUhFNtUggvZMZDsJv7blNVp5962PF1cPjmlT5UhGgyardLm LA0n23nxmMu1wz5jgOrM6MK3fIjEw1uBjv3GhBXVMbhVzkElmTc2O3UraLsSpZ7hauDG kCUw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:arc-authentication-results; bh=V4gtJSl/u7hCxrLY9HqLhirJwRptiH/LaH6KMfIoDE8=; b=AOIxCS9dDZe/5SgIm1AtYbepqU/V1gI9YY6pqgGbz5pIpyp897xfjyqpT51XQio+eO Q1elRhoMkf0pc7MmU1EnlPRx3zDvaI4GAQ4vEffTeL/2TFhF3My+Gs3qMfN0ReDj4kPH 2YK4KUNHSYUv0/6iixT6N8BuNQz91S3O4glaKy/ELMeDz2A+pHhtebeX6P7kA5tFt29l b5ROi3mNk9Qk8nA+QixAQRINwHQDEdbzCvLOct6ZiqcFndYQU4i92St9elE7J0P+zozd H80s4x/dTGayS1uojrNErBRILtAEDrLORIgfL9mt5VB59ko+1Ci/THZSz4/fxSiXTcpu O0pw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of bp@alien8.de designates 2a01:4f8:190:11c2::b:1457 as permitted sender) smtp.mailfrom=bp@alien8.de Authentication-Results: mx.google.com; spf=pass (google.com: domain of bp@alien8.de designates 2a01:4f8:190:11c2::b:1457 as permitted sender) smtp.mailfrom=bp@alien8.de Date: Thu, 25 Jan 2018 18:53:34 +0100 From: Borislav Petkov To: David Woodhouse Cc: Josh Poimboeuf , tim.c.chen@linux.intel.com, pjt@google.com, jikos@kernel.org, gregkh@linux-foundation.org, dave.hansen@intel.com, mingo@kernel.org, riel@redhat.com, luto@amacapital.net, torvalds@linux-foundation.org, ak@linux.intel.com, keescook@google.com, peterz@infradead.org, tglx@linutronix.de, hpa@zytor.com, linux-kernel@vger.kernel.org, linux-tip-commits@vger.kernel.org Subject: Re: [tip:x86/pti] x86/retpoline: Fill return stack buffer on vmexit Message-ID: <20180125175334.7wlin4ftnqkq2fil@pd.tnic> References: <1515755487-8524-1-git-send-email-dwmw@amazon.co.uk> <20180125120743.ey32gvl5mjam4r2s@pd.tnic> <1516882849.30244.94.camel@infradead.org> <20180125124554.vdx7rrnfrxrzl2ng@pd.tnic> <20180125151024.bidjr26r667vs7h5@treble> <20180125155110.mw655b7fwgm7qqc7@pd.tnic> <1516896198.30244.133.camel@infradead.org> <20180125165646.ytc4upthpaqtwi45@treble> <1516899639.30244.145.camel@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1516899639.30244.145.camel@infradead.org> User-Agent: NeoMutt/20170609 (1.8.3) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1589334225298273984?= X-GMAIL-MSGID: =?utf-8?q?1590587897514419016?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Thu, Jan 25, 2018 at 05:00:39PM +0000, David Woodhouse wrote: > And the whole problem here is that patching it in with alternatives is > painful on kernels < 4.1 because back then, we didn't cope with > oldinstr and altinstr being different lengths. > > And they don't want to fix *that* because kABI... So if it were only because of the KABI, I would never sent a mail on the list but would've done it in our tress and forgotten about it. [ And just to set one thing straight: I'm not the right person to complain to about KABI. ] Now, I happen to think that those macros could be simplified regardless. And I don't see *anything* wrong with that. Like making them more readable, simpler, etc, etc. That's the only reason why I raised the issue here. I mentioned the KABI because I didn't want to leave anything out from the whole picture. So forget the KABI angle and think: simpler, cleaner, more readable macros. Oh, and David, if while doing so I manage to add the alignment, then *that* is even better. Win-win-effing-win situation! -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.