2015-03-18 15:08 GMT+03:00 H.J. Lu <hjl.to...@gmail.com>:
> On Wed, Mar 18, 2015 at 5:05 AM, Ilya Enkovich <enkovich....@gmail.com> wrote:
>> 2015-03-18 15:02 GMT+03:00 H.J. Lu <hjl.to...@gmail.com>:
>>> On Wed, Mar 18, 2015 at 4:56 AM, Ilya Enkovich <enkovich....@gmail.com>
>>> 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 <ilya.enkov...@intel.com>
>>>>
>>>> PR driver/65444
>>>> * config/i386/linux-common.h (MPX_SPEC): New.
>>>> (CHKP_SPEC): Add MPX_SPEC.
>>>>
>>>> libmpx/
>>>>
>>>> 2015-03-18 Ilya Enkovich <ilya.enkov...@intel.com>
>>>>
>>>> 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.
