From owner-svn-src-head@FreeBSD.ORG Sun Jul 6 19:21:58 2014 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 433A4F17; Sun, 6 Jul 2014 19:21:58 +0000 (UTC) Received: from i3mail.icecube.wisc.edu (i3mail.icecube.wisc.edu [128.104.255.23]) by mx1.freebsd.org (Postfix) with ESMTP id 16C732D3A; Sun, 6 Jul 2014 19:21:57 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by i3mail.icecube.wisc.edu (Postfix) with ESMTP id 7A81138060; Sun, 6 Jul 2014 14:21:57 -0500 (CDT) X-Virus-Scanned: amavisd-new at icecube.wisc.edu Received: from i3mail.icecube.wisc.edu ([127.0.0.1]) by localhost (i3mail.icecube.wisc.edu [127.0.0.1]) (amavisd-new, port 10030) with ESMTP id cdEJQxPz0SVp; Sun, 6 Jul 2014 14:21:57 -0500 (CDT) Received: from comporellon.tachypleus.net (polaris.tachypleus.net [75.101.50.44]) by i3mail.icecube.wisc.edu (Postfix) with ESMTPSA id DD2133805B; Sun, 6 Jul 2014 14:21:56 -0500 (CDT) Message-ID: <53B9A1CD.2010803@freebsd.org> Date: Sun, 06 Jul 2014 12:21:49 -0700 From: Nathan Whitehorn User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Andrew Turner , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r268310 - head/libexec/rtld-elf/arm References: <201407061024.s66AO6R9012248@svn.freebsd.org> In-Reply-To: <201407061024.s66AO6R9012248@svn.freebsd.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 06 Jul 2014 19:21:58 -0000 Thank you! I can now upgrade my AVILA for the first time in 3 years. Most things seem to work fine, despite the long absence. -Nathan On 07/06/14 03:24, Andrew Turner wrote: > Author: andrew > Date: Sun Jul 6 10:24:06 2014 > New Revision: 268310 > URL: http://svnweb.freebsd.org/changeset/base/268310 > > Log: > Align the stack in _rtld_bind_start. Normally this is called with the > correct stack alignment, however when we have a leaf function that uses > thread local storage it calls __aeabi_read_tp to get the thread pointer. > Neither GCC or clang see this as a function call so will align the stack > to a 4-byte boundary. This may be a problem as _rtld_bind expects to be > on an 8-byte boundary. > > The solution is to store a copy of the stack pointer and force the > alignment before calling _rtld_bind. > > This fixes a problem with armeb where applications would crash in odd ways. > It should also remove the need for a local patch to clang to force the > stack alignment to an 8-byte boundary, even for leaf functions. Further > testing will be needed before reverting this local change to clang as we > may rely on it in other places. > > Reviewed by: jmg@ > > Modified: > head/libexec/rtld-elf/arm/rtld_start.S > > Modified: head/libexec/rtld-elf/arm/rtld_start.S > ============================================================================== > --- head/libexec/rtld-elf/arm/rtld_start.S Sun Jul 6 07:34:18 2014 (r268309) > +++ head/libexec/rtld-elf/arm/rtld_start.S Sun Jul 6 10:24:06 2014 (r268310) > @@ -77,7 +77,7 @@ __FBSDID("$FreeBSD$"); > * lr = &GOT[2] > */ > _rtld_bind_start: > - stmdb sp!,{r0-r4,sl,fp} > + stmdb sp!,{r0-r5,sl,fp} > > sub r1, ip, lr /* r1 = 4 * (n + 1) */ > sub r1, r1, #4 /* r1 = 4 * n */ > @@ -86,11 +86,14 @@ _rtld_bind_start: > ldr r0, [lr, #-4] /* get obj ptr from GOT[1] */ > mov r4, ip /* save GOT location */ > > + mov r5, sp /* Save the stack pointer */ > + bic sp, sp, #7 /* Align the stack pointer */ > bl _rtld_bind /* Call the binder */ > + mov sp, r5 /* Restore the old stack pointer */ > > str r0, [r4] /* save address in GOT */ > mov ip, r0 /* save new address */ > > - ldmia sp!,{r0-r4,sl,fp,lr} /* restore the stack */ > + ldmia sp!,{r0-r5,sl,fp,lr} /* restore the stack */ > mov pc, ip /* jump to the new address */ > >