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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BE7A2EE6B73 for ; Tue, 10 Feb 2026 04:16:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 017076B0005; Mon, 9 Feb 2026 23:16:37 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id EDCCA6B0088; Mon, 9 Feb 2026 23:16:36 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DE81C6B0089; Mon, 9 Feb 2026 23:16:36 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id C69A96B0005 for ; Mon, 9 Feb 2026 23:16:36 -0500 (EST) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 5565E8B452 for ; Tue, 10 Feb 2026 04:16:36 +0000 (UTC) X-FDA: 84427235592.06.C096B3B Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) by imf22.hostedemail.com (Postfix) with ESMTP id 45168C0003 for ; Tue, 10 Feb 2026 04:16:34 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=fail ("headers rsa verify failed") header.d=zytor.com header.s=2026012301 header.b=bPjZ9Y2g; spf=pass (imf22.hostedemail.com: domain of hpa@zytor.com designates 198.137.202.136 as permitted sender) smtp.mailfrom=hpa@zytor.com; dmarc=pass (policy=none) header.from=zytor.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1770696994; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=lMA+e7t1AQwEppF56ecV3ZH9XLnQSHpFgr1CYZ9e58g=; b=DnGf4jUaj+08i7hGr5L1+/QFCeoIx1KWN9HK18HmrQcNsLrBT1+4UFTcqGM1JUxsxjsyP9 qR3zWgXp4ckPsFwfWbSf2d8wenY3CB5xjBezkOHLiuV6JdesUFPl10DFDplv1Ho0N+fxu/ 6Um+sFtT7JzKSJ+BD1WfyYcPalUAL20= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=fail ("headers rsa verify failed") header.d=zytor.com header.s=2026012301 header.b=bPjZ9Y2g; spf=pass (imf22.hostedemail.com: domain of hpa@zytor.com designates 198.137.202.136 as permitted sender) smtp.mailfrom=hpa@zytor.com; dmarc=pass (policy=none) header.from=zytor.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1770696994; a=rsa-sha256; cv=none; b=UN/1B1F9fEfsF6v4oEOrNW4KrpP8W7ZrGZ6QyWK6SVfx4VuGjHVnjI+mW4Yp+sFPRa2YWH uiFPqiMfN9JJJSddNp7HSHCJXgg/ieNVKzXqNrSscLn8IQutzKtFGPUQCMGWnOfCcTiDSF EjNbi0o8X6WZ4rH4uoR5+DSgp6PT/ck= Received: from ehlo.thunderbird.net (c-76-133-66-138.hsd1.ca.comcast.net [76.133.66.138]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 61A4Fqvg3149966 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Mon, 9 Feb 2026 20:15:53 -0800 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 61A4Fqvg3149966 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2026012301; t=1770696956; bh=lMA+e7t1AQwEppF56ecV3ZH9XLnQSHpFgr1CYZ9e58g=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=bPjZ9Y2gc8XthT6zR8auXTW7LY0+PoYLaGLDTGvP5fag/zuiuP5tQ6Cv1wveyTm57 ErTx2dN99MNaspd+H16qZxFGNWq4gETPUsrJoDgKj1PTeMhC7npPFbbF4bIVa8hIoO NukcLD2uJLbiJ77RYGLeLH/E/TPTD31/BxU422+TVn8WU5ZP6uSWIObtIO9TNOQPtb WrO0aiPQ/p3gP3xcrmc3gdEICDoxjGG11jNeQb1yAwO2td78+CCqjwFIVAJD9j7qFu w8xSdWmfKueV84Yjuxx6TQ07qAZiYO5eLrXtTlCq8NvgnA8cMYxrSIKl+Ol4AJQrzF 13NMFFJ2qFaNg== Date: Mon, 09 Feb 2026 20:15:46 -0800 From: "H. Peter Anvin" To: Xi Ruoyao , Jens Remus CC: "Jason A. Donenfeld" , "Peter Zijlstra (Intel)" , "Theodore Ts'o" , =?ISO-8859-1?Q?Thomas_Wei=DFschuh?= , Xin Li , Andrew Cooper , Andy Lutomirski , Ard Biesheuvel , Borislav Petkov , Brian Gerst , Dave Hansen , Ingo Molnar , James Morse , Jarkko Sakkinen , Josh Poimboeuf , Kees Cook , Nam Cao , Oleg Nesterov , Perry Yuan , Thomas Gleixner , Thomas Huth , Uros Bizjak , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-sgx@vger.kernel.org, x86@kernel.org, Indu Bhagat , Claudiu Zissulescu-Ianculescu , Heiko Carstens , Vasily Gorbik Subject: =?US-ASCII?Q?Re=3A_=5BPATCH_v4=2E1_06/10=5D_x86/entry/vdso32?= =?US-ASCII?Q?=3A_remove_open-coded_DWARF_in_sigreturn=2ES?= User-Agent: K-9 Mail for Android In-Reply-To: References: <20260106211856.560186-6-hpa@zytor.com> <223707e2-3231-4037-bd1f-490ddf6aeeb6@linux.ibm.com> Message-ID: <29D95765-BD93-451D-8FD8-54250ADE1DEB@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 45168C0003 X-Stat-Signature: dczezruz1hadqhjz69y4iqq5ukdu8bin X-Rspam-User: X-HE-Tag: 1770696994-204028 X-HE-Meta: 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 ocJRuUs2 VKLyNRZx25Kw2RCMlmBHjiYO38LjfHVr5BlT1MK+mcdsKHEI04XCNtjFeW87UAN5lfCJbhxe++t+uKRB0lRf1gNVb3PH+jgCx0DrVDPZNLEneU/NovYkDO9L+t0ZKM++jtPzOJRBLfaf5cQrUOxWBxSjH5bJeDenwvznFfq/Km9W9/sVMzj++tV1evHyTNZvzSmEbnbe3sHRjiojBWveYygjnVjV8GXWkpO88fF5tBCJNochSevOX/Ijz9gVvHJ8Js7X+DAA3RJeWQhRT1VpAbifEbU5GdpZFAGOfxRpBdcn7ju+EhnrfXDn7gXjkHuC+yy+EpoW8HeZzgYjXbsW6Ym0jm/XUva5ZwhGGWr/o3bMOnWE= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On February 9, 2026 7:11:25 PM PST, Xi Ruoyao wrote: >On Mon, 2026-02-02 at 19:57 -0800, H=2E Peter Anvin wrote: >> That hack dates back from before the signal frame extension=2E It is no >> longer necessary=2E > >Unfortunately at least it seems libgcc unwinder does not handle the >signal frame extension properly=2E The code reads: > > fde =3D _Unwind_Find_FDE (context->ra + _Unwind_IsSignalFrame (context)= - 1,=20 > &context->bases); > if (fde =3D=3D NULL) > { =20 >#ifdef MD_FALLBACK_FRAME_STATE_FOR > /* Couldn't find frame unwind info for this function=2E Try a > target-specific fallback mechanism=2E This will necessarily > not provide a personality routine or LSDA=2E */ > return MD_FALLBACK_FRAME_STATE_FOR (context, fs);=20 >#else > return _URC_END_OF_STACK; >#endif > } =20 > > fs->pc =3D context->bases=2Efunc; > > cie =3D get_cie (fde); > insn =3D extract_cie_info (cie, context, fs);=20 > >Thus, it indeed attempts to avoid subtracting 1 for a signal frame, but >=2E=2E=2E _Unwind_IsSignalFrame (context) actually extracts a flag in con= text >which will only be raised up by extract_cie_info=2E > >Or am I missing something here? > Oh, good grief=2E=2E=2E How does this possibly work on non-x86 platforms?