From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11517 invoked by alias); 18 Mar 2015 12:13:17 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 11508 invoked by uid 89); 18 Mar 2015 12:13:17 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=4.4 required=5.0 tests=AWL,BAYES_50,FREEMAIL_FROM,KAM_FROM_URIBL_PCCC,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=no version=3.3.2 X-HELO: mail-ob0-f182.google.com Received: from mail-ob0-f182.google.com (HELO mail-ob0-f182.google.com) (209.85.214.182) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Wed, 18 Mar 2015 12:13:07 +0000 Received: by obbgg8 with SMTP id gg8so30080397obb.1 for ; Wed, 18 Mar 2015 05:13:05 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.202.49.65 with SMTP id x62mr12712395oix.7.1426680785113; Wed, 18 Mar 2015 05:13:05 -0700 (PDT) Received: by 10.202.187.66 with HTTP; Wed, 18 Mar 2015 05:13:05 -0700 (PDT) In-Reply-To: References: <20150318115630.GA64546@msticlxl57.ims.intel.com> Date: Wed, 18 Mar 2015 12:13:00 -0000 Message-ID: Subject: Re: [PATCH, libmpx, i386, PR driver/65444] Pass '-z bndplt' when building dynamic objects with MPX From: Ilya Enkovich To: "H.J. Lu" Cc: GCC Patches , Uros Bizjak Content-Type: text/plain; charset=UTF-8 X-IsSubscribed: yes X-SW-Source: 2015-03/txt/msg00924.txt.bz2 2015-03-18 15:08 GMT+03:00 H.J. Lu : > On Wed, Mar 18, 2015 at 5:05 AM, Ilya Enkovich wrote: >> 2015-03-18 15:02 GMT+03:00 H.J. Lu : >>> On Wed, Mar 18, 2015 at 4:56 AM, Ilya Enkovich wrote: >>>> Hi, >>>> >>>> This patch fixes PR target/65444 by passing '-z bndplt' to linker when appropriate. Bootstrapped and tested on x86_64-unknown-linux-gnu. Will commit it to trunk in a couple of days if no objections arise. >>>> >>>> Thanks, >>>> Ilya >>>> -- >>>> gcc/ >>>> >>>> 2015-03-18 Ilya Enkovich >>>> >>>> PR driver/65444 >>>> * config/i386/linux-common.h (MPX_SPEC): New. >>>> (CHKP_SPEC): Add MPX_SPEC. >>>> >>>> libmpx/ >>>> >>>> 2015-03-18 Ilya Enkovich >>>> >>>> PR driver/65444 >>>> * configure.ac: Add check for '-z bndplt' support >>>> by linker. Add link_mpx output variable. >>>> * libmpx.spec.in (link_mpx): New. >>>> * configure: Regenerate. >>>> >>>> >>>> diff --git a/gcc/config/i386/linux-common.h b/gcc/config/i386/linux-common.h >>>> index 9c6560b..dd79ec6 100644 >>>> --- a/gcc/config/i386/linux-common.h >>>> +++ b/gcc/config/i386/linux-common.h >>>> @@ -59,6 +59,11 @@ along with GCC; see the file COPYING3. If not see >>>> %:include(libmpx.spec)%(link_libmpx)" >>>> #endif >>>> >>>> +#ifndef MPX_SPEC >>>> +#define MPX_SPEC "\ >>>> + %{mmpx:%{fcheck-pointer-bounds:%{!static:%:include(libmpx.spec)%(link_mpx)}}}" >>>> +#endif >>>> + >>>> #ifndef LIBMPX_SPEC >>>> #if defined(HAVE_LD_STATIC_DYNAMIC) >>>> #define LIBMPX_SPEC "\ >>>> @@ -89,5 +94,5 @@ along with GCC; see the file COPYING3. If not see >>>> >>>> #ifndef CHKP_SPEC >>>> #define CHKP_SPEC "\ >>>> -%{!nostdlib:%{!nodefaultlibs:" LIBMPX_SPEC LIBMPXWRAPPERS_SPEC "}}" >>>> +%{!nostdlib:%{!nodefaultlibs:" LIBMPX_SPEC LIBMPXWRAPPERS_SPEC "}}" MPX_SPEC >>>> #endif >>>> diff --git a/libmpx/configure.ac b/libmpx/configure.ac >>>> index fe0d3f2..3f8b50f 100644 >>>> --- a/libmpx/configure.ac >>>> +++ b/libmpx/configure.ac >>>> @@ -40,7 +40,18 @@ AC_MSG_RESULT($LIBMPX_SUPPORTED) >>>> AM_CONDITIONAL(LIBMPX_SUPPORTED, [test "x$LIBMPX_SUPPORTED" = "xyes"]) >>>> >>>> link_libmpx="-lpthread" >>>> +link_mpx="" >>>> +AC_MSG_CHECKING([whether ld accepts -z bndplt]) >>>> +echo "int main() {};" > conftest.c >>>> +if AC_TRY_COMMAND([${CC} ${CFLAGS} -Wl,-z,bndplt -o conftest conftest.c 1>&AS_MESSAGE_LOG_FD]) >>>> +then >>>> + AC_MSG_RESULT([yes]) >>>> + link_mpx="$link_mpx -z bndplt" >>>> +else >>>> + AC_MSG_RESULT([no]) >>>> +fi >>>> AC_SUBST(link_libmpx) >>>> +AC_SUBST(link_mpx) >>>> >>> >>> Without -z bndplt, MPX won't work correctly. We should always pass -z bndplt >>> to linker. If linker doesn't support it, ld will issue a warning, not >>> error and users >>> will know their linker is too old. When they update linker, they don't have to >>> rebuild GCC. >> >> If ld issues a warning instead of an error, then configure test passes >> and we pass '-z bndplt' to linker. >> > > Can you verify it with an older linker? The unknown XXX in -z XXX is always > warned and ignored in Linux linker. If testing it on Linux always passes, > it is useless. Old ld issues a warning: ld: warning: -z bndplt ignored. But gold issues an error: ld.gold: bndplt: unknown -z option ld.gold: use the --help option for usage information Ilya > > -- > H.J.