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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 79A90C83007 for ; Tue, 28 Apr 2020 11:11:44 +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 4977120661 for ; Tue, 28 Apr 2020 11:11:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="VvHY9y6G" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4977120661 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: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=Zs275Rb/UELjVlqmEWwutKpB5yHKxy26DAo/hFzuKzM=; b=VvHY9y6GtcVGXi fyqO+vuctoafck8L9POzwvDr6oXM1j3d75hJ/aB83J/rkIDs3H4EAul70RBbzGJ+p7xP7KQHFBENj 3rRHEiEjBkZqfnTYTb/dxVtnFdIr5fqAQmUMLMSO/NA0Bk/xEErLypxb+D/q66BVeyNJCKL3Er/I3 Yb5q4GnaxrvYUULqDIjFGGOssva/l0lmZJhUscxRSeGjH/pQSlr+QLJ7LvrpMmLXwWEcekWj9Ydt4 hl4Y5TzPU6yyp7rTDP6+pghdHtZiM/tF8J6YnVlQiODSLUCUmXRaP0hK2K/cKxoeIc1pTkoN0kT4J HvzNJaJHXX594RyNrJBQ==; 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 1jTO9I-0006Sv-BS; Tue, 28 Apr 2020 11:11:36 +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 1jTO9E-0006Ru-Ul for linux-arm-kernel@lists.infradead.org; Tue, 28 Apr 2020 11:11:34 +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 28D7030E; Tue, 28 Apr 2020 04:11:30 -0700 (PDT) Received: from C02TD0UTHF1T.local (unknown [10.57.1.132]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AEA0E3F73D; Tue, 28 Apr 2020 04:11:28 -0700 (PDT) Date: Tue, 28 Apr 2020 12:11:23 +0100 From: Mark Rutland To: Vincenzo Frascino Subject: Re: arm64 vdso might miss .eh_frame Message-ID: <20200428111123.GA15519@C02TD0UTHF1T.local> References: <20200415092336.GK987@arm.com> <20200428073435.GC4049@willie-the-truck> <152f54d5-2fa9-bc08-d931-ed2f3675da6b@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <152f54d5-2fa9-bc08-d931-ed2f3675da6b@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200428_041133_036589_A0586B6D X-CRM114-Status: GOOD ( 17.84 ) 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: Szabolcs Nagy , Catalin Marinas , Will Deacon , 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 Tue, Apr 28, 2020 at 11:54:25AM +0100, Vincenzo Frascino wrote: > 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. Can I suggest that you post the patch as-is here, even if it's not complete, so that we can all review/test in parallel? If you do that and explicitly ask Tamas for specific feedback in that posting, it'll be obvious to everyone what's expected and where things stand. Thanks, Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel