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 048A7C83000 for ; Tue, 28 Apr 2020 07:35:00 +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 A942F206D6 for ; Tue, 28 Apr 2020 07:34:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="OTE8Ts1S"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="lLyX/U4T" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A942F206D6 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=k+RakUpKHElOo3rbPkFb3uWfKjm0bniMA9i3jdt18rM=; b=OTE8Ts1SRcvayZ oEYsEdxqphNlGoRg71+fP1jYbQ7xl5O1+73tp7+PRpD3qFVSO0IrrKBvlTkUfZhuV346wGZnfzMUx PW+ZJo3/C9esWBqO6cJM2fS53Cidc8ApnNZkFsRx/ubIe9P+2pX8UMXHbTxtoC9+FISyuqtLpoS+D +fnk4WSJWbPUBKX89UhYuym8TsGRAXM7lo7ZFpGz9YC70bar8eC10a3nGaa5JCvrtYgSjEY9+wyMj z9L+1IkN6NM367NLSB87vWvJBrH4qV9drc58JM+tkuS6lgZ1OkpBeXXMu1zIuuxiPKXUBl57icDdN m+bvk0f8Z7L8pQsnOvbQ==; 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 1jTKle-0005rv-05; Tue, 28 Apr 2020 07:34:58 +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 1jTKlM-0005bq-DG for linux-arm-kernel@lists.infradead.org; Tue, 28 Apr 2020 07:34:41 +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 EF906206D9; Tue, 28 Apr 2020 07:34:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588059280; bh=Ij7cKVnIonfucw210eJQSpASNDrQWgMhCCdpFFpQWvc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lLyX/U4TLpN1vT2REDLFDIRX7lLSspJBA8MAcJxiUXiClH0a60z5PNE8mvoCJrxLy wrR5yCHzRZdq43COnv6rpOCsMN/kGmwYk3F1iURnolKcMcgoxLrrp4q/RZaT7MStPJ oB85UMPKlpyPwkCi31jO8hHcBj1AiGelx6BiRQaY= Date: Tue, 28 Apr 2020 08:34:35 +0100 From: Will Deacon To: Szabolcs Nagy Subject: Re: arm64 vdso might miss .eh_frame Message-ID: <20200428073435.GC4049@willie-the-truck> References: <20200415092336.GK987@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200415092336.GK987@arm.com> 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-20200428_003440_472686_AD6FDD8D X-CRM114-Status: GOOD ( 13.46 ) 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 , Vincenzo Frascino , 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 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? Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel