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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 131BEC43441 for ; Mon, 26 Nov 2018 23:41:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CDD9C2082F for ; Mon, 26 Nov 2018 23:41:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="U/R6z8fv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CDD9C2082F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727945AbeK0Kh2 (ORCPT ); Tue, 27 Nov 2018 05:37:28 -0500 Received: from pandora.armlinux.org.uk ([78.32.30.218]:49932 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727630AbeK0Kh2 (ORCPT ); Tue, 27 Nov 2018 05:37:28 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2014; h=Sender: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-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=oRH6j1u5aPuU+XLEK3cSURgeMBYJ/6FdLObXeu+cT7c=; b=U/R6z8fvq8bZRqvrmYp2I3Aul dhYWwDEPua+r4F/hAWS7cu8+KOnbILgiS2VOZpsomQ2Mpa5abvXdVWDmRhCs1N+u11ewuticygjAa nqzzYKmv8BPxLz7554gjMpxCuUr4B/uIHCg6wYaVH1L3LulgU/3rCrNdFXUujL1oThbsQ=; Received: from n2100.armlinux.org.uk ([2002:4e20:1eda:1:214:fdff:fe10:4f86]:54715) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.90_1) (envelope-from ) id 1gRQVF-0003f6-5i; Mon, 26 Nov 2018 23:41:21 +0000 Received: from linux by n2100.armlinux.org.uk with local (Exim 4.90_1) (envelope-from ) id 1gRQV8-0004DV-RF; Mon, 26 Nov 2018 23:41:15 +0000 Date: Mon, 26 Nov 2018 23:41:11 +0000 From: Russell King - ARM Linux To: Rafael David Tinoco Cc: Vladimir Murzin , Vincent Whitchurch , Nick Desaulniers , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Masahiro Yamada , Mathieu Desnoyers , Thomas Gleixner , Timothy E Baldwin , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] arm: always update thread_info->syscall Message-ID: <20181126234111.GA30658@n2100.armlinux.org.uk> References: <20181126225335.10477-1-rafael.tinoco@linaro.org> <20181126233303.GZ30658@n2100.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181126233303.GZ30658@n2100.armlinux.org.uk> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 26, 2018 at 11:33:03PM +0000, Russell King - ARM Linux wrote: > On Mon, Nov 26, 2018 at 08:53:35PM -0200, Rafael David Tinoco wrote: > > Right now, only way for task->thread_info->syscall to be updated is if > > if _TIF_SYSCALL_WORK is set in current's task thread_info->flags > > (similar to what has_syscall_work() checks for arm64). > > > > This means that "->syscall" will only be updated if we are tracing the > > syscalls through ptrace, for example. This is NOT the same behavior as > > arm64, when pt_regs->syscallno is updated in the beginning of svc0 > > handler for *every* syscall entry. > > So when was it decided that the syscall number will always be required > (we need it to know how far back this has to be backported). PS, I rather object to the fact that the required behaviour seems to change, arch maintainers aren't told about it until... some test is created at some random point in the future which then fails. Surely there's a better way to communicate changes in requirements than discovery-by-random-bug-report ? -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up