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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 D6F6EC34026 for ; Tue, 18 Feb 2020 08:44:13 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id A71362064C for ; Tue, 18 Feb 2020 08:44:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="B6WozjhU"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="l1poJR8E" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A71362064C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=OFI2Qj9Wm8b+h5ZtPqZurLIPxxTgV/AK1da9AabsMtk=; b=B6WozjhUOmX1ae MhHSDCRgRu5HYaEcsGLdLB9C2uvHLOJRIlBb5WhJYJIbHt2A9wZuC6G+FWtlpLg+geXke2Vtr64dw I82EcTOgFqUwdNrghVBAp9+utYvvax/QJttpvCoofahlLBK0/ZIAH3I/qNS1OWpwrpNO8g2HUD3iB dMhurCTsH0vGf/bUw7h/DQoiZ85zemKiLqEyhWGfSYX+wvlJZVw/cttrcOWk8Lx3XV6rfQtMDbV4j Li0jRY4HcjG9BLBRosmRwm5b07Lmh4/UpGcVy29j8xyAKdmiW8GRd0WiMHnI0cijisPywsslNQSq0 QI8RYOm6zy+8XWx4Mqew==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j3yUC-0007Aj-Bd; Tue, 18 Feb 2020 08:44:08 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1j3yU9-0007AE-Qg for linux-arm-kernel@lists.infradead.org; Tue, 18 Feb 2020 08:44:07 +0000 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7D91E2064C; Tue, 18 Feb 2020 08:44:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582015444; bh=TlD3FF2u/0sqf8LJx48N5oNM15qLnrXXYkP0fgRyaeo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=l1poJR8E/j4pRBB53WHbcZzE9dKNVva5vwMhuhFkRxktBMh/X8qvtbscl1z9cciXj igQC+Yfu6w7JdQ6zrF9byK0cFV2kUwbjC7V8KhbHKyflJrtY5Vpgqz7YPHsNvze1Cu 2Cs4upukx3CD7jOr+2xlf8KdjQ1eqAXp9sU7kb3M= Date: Tue, 18 Feb 2020 08:44:00 +0000 From: Will Deacon To: Luis Machado Subject: Re: [arm64, debug] PTRACE_SINGLESTEP does not single-step a valid instruction Message-ID: <20200218084359.GA16828@willie-the-truck> References: <1eed6d69-d53d-9657-1fc9-c089be07f98c@linaro.org> <20191118131525.GA4180@willie-the-truck> <307ece3d-4e9d-21c4-0abf-9f4f3b313e74@linaro.org> <82cb3dea-db82-1c71-3b08-957102b85c93@linaro.org> <20200213120115.GD1405@willie-the-truck> <5028f457-5b7d-1a88-912f-3fa97b567985@linaro.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <5028f457-5b7d-1a88-912f-3fa97b567985@linaro.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200218_004405_888131_D78C4B6A X-CRM114-Status: GOOD ( 22.62 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Feb 14, 2020 at 12:45:31PM -0300, Luis Machado wrote: > On 2/13/20 2:07 PM, Luis Machado wrote: > > On 2/13/20 9:01 AM, Will Deacon wrote: > > > Sorry for the very slow reply. I talked to Mark about this a bit but it > > > seems that we never followed up here. > > > > No worries. > > > > > > > > On Tue, Dec 10, 2019 at 05:00:18PM -0300, Luis Machado wrote: > > > > Do you have any input regarding this particular situation? > > > > > > > > It would be nice to get this fixed before the release of another GDB > > > > version, if the fix is to live in GDB itself. > > > > > > Basically, I'm very nervous about fixing this in the kernel because > > > whatever we do will be visible to userspace. On the other hand, this > > > part of the ptrace interface is only seriously used by GDB and we should > > > make sure that it works well. > > > > > > Does the diff below solve the problem? If so, can you confirm that it > > > doesn't appear to regress anything else for GDB? > > > > Thanks for the patch. I'll exercise this in various ways to see if > > anything breaks. > > > > I gave this a try with the particular test in GDB's testsuite that exposed > the problem. It is working as expected now, so we're single-stepping past > the instruction correctly instead of getting a spurious SIGTRAP. > > I managed to run a few other tests related to syscalls and signals and they > also executed as expected. But this was inside QEMU. > > Do you see any potential scenarios where this change may break things? Other > things i should try to exercise? Could you run the entire testsuite please and check there aren't any regressions? Hardware would be best, but QEMU is still useful. > Given we need to be careful with a kernel patch at this stage, i just want > to make sure I covered all/most the possible cases. > > Otherwise, I'm happy with this change. Thanks for putting it together! I'll add your Tested-by, but I'd still like review from Mark. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel