From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from eggs.gnu.org (eggs.gnu.org [IPv6:2001:470:142:3::10]) by sourceware.org (Postfix) with ESMTPS id 03E443858D28 for ; Fri, 17 Mar 2023 17:07:36 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 03E443858D28 Authentication-Results: sourceware.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=linaro.org Received: from mail-pf1-x42b.google.com ([2607:f8b0:4864:20::42b]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pdDYC-0005B8-6I for gdb@gnu.org; Fri, 17 Mar 2023 13:07:34 -0400 Received: by mail-pf1-x42b.google.com with SMTP id z11so3524344pfh.4 for ; Fri, 17 Mar 2023 10:07:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1679072850; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=XP8Q2FI1U9PJPNNWvkZAKAWR8a38tAxxBoCJWVesujc=; b=Uah1eNVpm5n38JC5SwvtsZEJXJl9oB5JWpI6gL8dfXJUjb7GCtWZp1cml9ukoav3Kn nXuTUUx45ztzILyJlZknso75cQaJvsqeUumBvBwPMrjTPYyqCenVuPuWLc8mTEoDP5TY 1a3S0wOLMKmeteN30Q1KPOQj8nLUQUGbYj9+cHKFrE/zMHEiqdVdcod7y/3Jt9MYklRx EdEwGtocc13qKkhKOjSMOYoxQe2NE+83WOaqoB7rQ3JMFR8vRYxjboSggr35fekpScgd 2DJx3Oh66RyFw2SyLwMeMJ83Zvw2N9H3hdPgKGL3s6WHpX/YI9LP5d+OP3yb448n1HQ1 2eDA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679072850; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=XP8Q2FI1U9PJPNNWvkZAKAWR8a38tAxxBoCJWVesujc=; b=iXEy523xypDHcs9X/GdVWWMDe49ERhm8Qiuq/tkjjlVMRqS6q4a3z8wa1XuxsLcpce 7s1ZHhzR41jU6QYRm/1ImbqeGgxB6lhRe7oCKUW7JcRSV39xsnfbZJyce/yJxp8DIJCO tVjt2Z3xXaaajROjq9ICJqXmwjDDiqk74AriQxZh3DgBf2NLY+gqRfRXkqLRdY31NR8H KG+5T3AoBbKagKUWWntEWPnBcHTa+QzvldAcb2k0Vl3wg1S411Q3y697IwF3TNsIaedp Kunp+Dc62khZo94bDO6vgPsGIVduW8Cfzw9VEWH5wkJmQCUMP2enP0UQI/Zlbrsj64VE ATPA== X-Gm-Message-State: AO0yUKU5gACOHcn1eC7uMytlv9hK9weXbK0hK/efW5LQOQ+1R/+t9f8q x2l/8bV1WexXr/5e9ww7j5lmsKFfVB7I9H/hvm7lrQ== X-Google-Smtp-Source: AK7set91JaoAQhC93HH4dnDd5zdv+X5Z1/Kkld/Kkifoo5YfoFvlj57xdPK2jluw+C5LucBDQcjSUsyLqUcr+e+cm2c= X-Received: by 2002:a65:400c:0:b0:50c:bd0:eb8c with SMTP id f12-20020a65400c000000b0050c0bd0eb8cmr918540pgp.6.1679072850499; Fri, 17 Mar 2023 10:07:30 -0700 (PDT) MIME-Version: 1.0 References: <20230310103123.2118519-1-alex.bennee@linaro.org> <20230310103123.2118519-10-alex.bennee@linaro.org> <87wn3ocwqz.fsf@suse.de> <87sfeclb8o.fsf@linaro.org> <9bb8ab52-c6ae-95a7-e6c8-64bcce166c19@arm.com> <7b032516-913f-87fa-eeb7-c38a8676465a@arm.com> In-Reply-To: <7b032516-913f-87fa-eeb7-c38a8676465a@arm.com> From: Peter Maydell Date: Fri, 17 Mar 2023 17:07:18 +0000 Message-ID: Subject: Re: [PATCH 09/11] tests/tcg: disable pauth for aarch64 gdb tests To: Luis Machado Cc: =?UTF-8?B?QWxleCBCZW5uw6ll?= , Fabiano Rosas , qemu-devel@nongnu.org, David Hildenbrand , Wainer dos Santos Moschetta , Richard Henderson , qemu-arm@nongnu.org, Peter Xu , =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= , Cleber Rosa , Thomas Huth , Paolo Bonzini , Beraldo Leal , gdb , Thiago Jung Bauermann , Omair Javaid Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2607:f8b0:4864:20::42b; envelope-from=peter.maydell@linaro.org; helo=mail-pf1-x42b.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9,DKIM_SIGNED=0.1,DKIM_VALID=-0.1,DKIM_VALID_AU=-0.1,DKIM_VALID_EF=-0.1,RCVD_IN_DNSWL_NONE=-0.0001,SPF_HELO_NONE=0.001,SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-Spam-Status: No, score=-3.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_PASS,SPF_SOFTFAIL,TXREP autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Fri, 17 Mar 2023 at 16:55, Luis Machado wrote: > On 3/17/23 16:37, Peter Maydell wrote: > > Having run into this problem in another couple of situations, one of > > which involved gdb 10, I think I'm increasingly favouring option > > 2 here. The affected gdbs seem to be quite widely deployed, and > > the bug results in crashes even for users who didn't really > > care about pauth. So I'd rather we didn't release a QEMU 8.0 > > which crashes these affected deployed gdbs. > > > > Are the affected gdb's packaged by distros? If so, a backport the distros can pick up > will solve this in a quick package update. Yes, it's exactly because these gdbs are distro-packaged that I don't want QEMU to make them crash. I think it's going to take a long time for the fix to go into gdb branches and gdb to make a point release and distros to pick up that point release, and in the meantime that's a lot of crashing gdb bug reports that we're going to have to field. > If we decide qemu should now emit a different xml for pauth, it will fix the crashes, but it also > means older gdb's (9/10/11/12) will not be able to backtrace properly through pauth-signed frames. > > Maybe that's a reasonable drawback for qemu users? "No backtrace through pauth frames" is the situation we've been in ever since we implemented pauth in 2019, so I think that's fine. It's not regressing something that used to work. > If someone decides to implement a debugging stub that reports pauth (fast models, for example), it will > also crash gdb, so I still plan to do the backport anyway. If you're backporting the fix, you could also backport the (hopefully tiny) change that says "treat pauth_v2 the same way we do pauth", and then users with an updated older gdb will also get working backtraces. thanks -- PMM