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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 1334CC83000 for ; Tue, 28 Apr 2020 10:53:33 +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 B4843206D6 for ; Tue, 28 Apr 2020 10:53:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="p2NpDfle" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B4843206D6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com 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:Date: Message-ID:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=48MBXfAy7NKA3NX+y6ixpRYFVP2e5mu2Qm4XPbRtJXs=; b=p2NpDfleQ5Ewiu tymYkEjzLdnWwyneTQy9GoUmhzX0vDXrVuGPiwAWeG7oeTVOftAkSb4dwjHrMuv7eVgZbHPln9gjn C6LOsP8FIEFKrRetaDWZl8by2DH/gkVUaJmmnSa1cJWNhl6f7TENJuYKoTmN3HuIIQrvVysGGUz+2 rpEzurgcN0OsDn1Tm79SwEaWjuy1JVBbKvU8nzLliVPexyrbQH4mqjdIKltVfjXXANqPDU+aRzvPx mXA5yoeaZjXIjkJ0RVzyfH32Xfd4fANUGK5maYGOvVf+I6wcDy0R9Wb3B0azy32QpK2y3Y1lasSaM S9aUVY5GDPbwZdK2MWOQ==; 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 1jTNro-0001nz-4I; Tue, 28 Apr 2020 10:53:32 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jTNrl-0001nP-2y for linux-arm-kernel@lists.infradead.org; Tue, 28 Apr 2020 10:53:30 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 57B2130E; Tue, 28 Apr 2020 03:53:28 -0700 (PDT) Received: from [10.37.8.217] (unknown [10.37.8.217]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DB2B43F73D; Tue, 28 Apr 2020 03:53:26 -0700 (PDT) Subject: Re: arm64 vdso might miss .eh_frame To: Will Deacon , Szabolcs Nagy References: <20200415092336.GK987@arm.com> <20200428073435.GC4049@willie-the-truck> From: Vincenzo Frascino Message-ID: <152f54d5-2fa9-bc08-d931-ed2f3675da6b@arm.com> Date: Tue, 28 Apr 2020 11:54:25 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20200428073435.GC4049@willie-the-truck> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200428_035329_172900_86DA4AA4 X-CRM114-Status: GOOD ( 16.83 ) 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 , Catalin Marinas , linux-arm-kernel@lists.infradead.org, Tamas Zsoldos 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 Hi Will, On 4/28/20 8:34 AM, Will Deacon wrote: > On Wed, Apr 15, 2020 at 10:23:36AM +0100, Szabolcs Nagy wrote: >> On aarch64 linux gcc uses -fasynchronous-unwind-tables -funwind-tables >> by default since gcc-8, so now the de facto platform ABI is to allow >> unwinding from async signal handlers. >> >> However on bare metal targets (aarch64-none-elf), and on old gcc, >> async and sync unwind tables are not enabled by default to avoid >> runtime memory costs. >> >> This means if linux is built with a baremetal toolchain the vdso.so >> may not have unwind tables which breaks our (undocumented) platform >> ABI guarantee in userspace. So adding -fasynchronous-unwind-tables >> explicitly to the vgettimeofday.o cflags would be nice (the other >> objects in the vdso seem to be asm). >> >> There was also a report that android clang built linux vdso.so lacks >> .eh_frame completely, that may be a missing --eh-frame-hdr or different >> platform ABI on android, Tamas on cc may be able to verify this. > > Vincenzo? Looks like this is a regression caused by the move to C -- please > can you take a look? > I have already, locally, a patch that addresses the problem presented in this email, based on Szabolcs comment. I did not post it yet because I was waiting for Tamas' comment and address everything in one go. Let me know if you need it before then that. > Will > -- Regards, Vincenzo _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel