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,URIBL_BLOCKED,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 C2C69C83000 for ; Tue, 28 Apr 2020 11:15:32 +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 34FB620663 for ; Tue, 28 Apr 2020 11:15:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="DxdfA2W/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 34FB620663 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=2rSxNH2mMSqG1fH3IPsLY56DXEI6+KpXiRZwY8YUI1M=; b=DxdfA2W/WTkwdD Lu9HeZNiC2byAJbw+FJvvBhlAAG8fU4hezO40QxUlSE88avX8FdNCQHi1pTwrGLIDEPA4GZknybqK wCon48Wq/G3G32M+CzBdg/SWCZ7dXE0NHGUpk8dTxalECCK4h5kcd6/pTEIWB8cx6fu85x7u23XyW AGuTiItYLr0trrpuUrsw8NvoQ44q1KOF4VLI4ksawZ4J0JDxPg1Gp68upNkvRm5/mkCb+2igLwMqr BdeyzwR/+VZyYx+KcLRbrRltxNmlpSHm8hZ0YIlXh9vSzGOCj6xPfJANpYp73bGxOlcm78/+/IV0/ rqJ5FPVlcMW4k7YsUq5w==; 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 1jTOD3-00022F-U3; Tue, 28 Apr 2020 11:15:29 +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 1jTOCO-0007dr-Iy for linux-arm-kernel@lists.infradead.org; Tue, 28 Apr 2020 11:14:50 +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 1912130E; Tue, 28 Apr 2020 04:14:48 -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 ED21C3F73D; Tue, 28 Apr 2020 04:14:46 -0700 (PDT) Subject: Re: arm64 vdso might miss .eh_frame To: Mark Rutland References: <20200415092336.GK987@arm.com> <20200428073435.GC4049@willie-the-truck> <152f54d5-2fa9-bc08-d931-ed2f3675da6b@arm.com> <20200428111123.GA15519@C02TD0UTHF1T.local> From: Vincenzo Frascino Message-ID: Date: Tue, 28 Apr 2020 12:15:46 +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: <20200428111123.GA15519@C02TD0UTHF1T.local> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200428_041448_678543_F0DFF544 X-CRM114-Status: GOOD ( 16.69 ) 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 Hi Mark, On 4/28/20 12:11 PM, Mark Rutland wrote: > 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? > Sure, I will write a sensible comment and send it out. > 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. > -- Regards, Vincenzo _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel