From owner-svn-src-stable-8@FreeBSD.ORG Fri Jun 18 09:34:32 2010 Return-Path: Delivered-To: svn-src-stable-8@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1B42A1065672; Fri, 18 Jun 2010 09:34:32 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c]) by mx1.freebsd.org (Postfix) with ESMTP id 09EAB8FC20; Fri, 18 Jun 2010 09:34:32 +0000 (UTC) Received: from svn.freebsd.org (localhost [127.0.0.1]) by svn.freebsd.org (8.14.3/8.14.3) with ESMTP id o5I9YV4c016498; Fri, 18 Jun 2010 09:34:31 GMT (envelope-from kib@svn.freebsd.org) Received: (from kib@localhost) by svn.freebsd.org (8.14.3/8.14.3/Submit) id o5I9YV3F016496; Fri, 18 Jun 2010 09:34:31 GMT (envelope-from kib@svn.freebsd.org) Message-Id: <201006180934.o5I9YV3F016496@svn.freebsd.org> From: Konstantin Belousov Date: Fri, 18 Jun 2010 09:34:31 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-8@freebsd.org X-SVN-Group: stable-8 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Subject: svn commit: r209292 - stable/8/sys/i386/i386 X-BeenThere: svn-src-stable-8@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for only the 8-stable src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 18 Jun 2010 09:34:32 -0000 Author: kib Date: Fri Jun 18 09:34:31 2010 New Revision: 209292 URL: http://svn.freebsd.org/changeset/base/209292 Log: MFC r208604: Clarify a potential issue in get_fpcontext() use. Modified: stable/8/sys/i386/i386/machdep.c Directory Properties: stable/8/sys/ (props changed) stable/8/sys/amd64/include/xen/ (props changed) stable/8/sys/cddl/contrib/opensolaris/ (props changed) stable/8/sys/contrib/dev/acpica/ (props changed) stable/8/sys/contrib/pf/ (props changed) stable/8/sys/dev/xen/xenpci/ (props changed) stable/8/sys/geom/sched/ (props changed) Modified: stable/8/sys/i386/i386/machdep.c ============================================================================== --- stable/8/sys/i386/i386/machdep.c Fri Jun 18 09:29:08 2010 (r209291) +++ stable/8/sys/i386/i386/machdep.c Fri Jun 18 09:34:31 2010 (r209292) @@ -633,6 +633,13 @@ sendsig(sig_t catcher, ksiginfo_t *ksi, sf.sf_uc.uc_mcontext.mc_gs = rgs(); bcopy(regs, &sf.sf_uc.uc_mcontext.mc_fs, sizeof(*regs)); sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext); /* magic */ + + /* + * The get_fpcontext() call must be placed before assignments + * to mc_fsbase and mc_gsbase due to the alignment-override + * code in get_fpcontext() that possibly clobbers 12 bytes of + * mcontext after mc_fpstate. + */ get_fpcontext(td, &sf.sf_uc.uc_mcontext); fpstate_drop(td); /* @@ -3241,6 +3248,13 @@ get_mcontext(struct thread *td, mcontext mcp->mc_esp = tp->tf_esp; mcp->mc_ss = tp->tf_ss; mcp->mc_len = sizeof(*mcp); + + /* + * The get_fpcontext() call must be placed before assignments + * to mc_fsbase and mc_gsbase due to the alignment-override + * code in get_fpcontext() that possibly clobbers 12 bytes of + * mcontext after mc_fpstate. + */ get_fpcontext(td, mcp); sdp = &td->td_pcb->pcb_gsd; mcp->mc_fsbase = sdp->sd_hibase << 24 | sdp->sd_lobase;