Re: [PING] Re: Add check for -no-pie if the compiler default to -fPIE

[Andrei Borzenkov]

Committed. Thanks!

09.11.2016 01:01, Magnus Granberg пишет:
> söndag 6 november 2016 kl. 10:05:53 CET skrev du:
>> 21.10.2016 00:26, Magnus Granberg пишет:
>>> lördag 21 maj 2016 kl. 20:53:48 CEST skrev du:
>>>> On Saturday 21 May 2016 19.26.18 you wrote:
>>>>> 21.05.2016 19:02, Magnus Granberg пишет:
>>>>>> On Saturday 21 May 2016 18.55.11 you wrote:
>>>>>>> 21.05.2016 17:47, Magnus Granberg пишет:
>>>>>>>> When Grub is compile with gcc 6.1 that have --enable-defult-pie set.
>>>>>>>> It fail with.
>>>>>>>> -ffreestanding   -m32 -Wl,-melf_i386 -Wl,--build-id=none  -nostdlib
>>>>>>>> -Wl,-N
>>>>>>>> -Wl,-r,-d   - o trig.module  trig_module-trigtables.o
>>>>>>>> grep 'MARKER' gcry_whirlpool.marker.new > gcry_whirlpool.marker; rm
>>>>>>>> -f
>>>>>>>> gcry_whirlpool.marker.new
>>>>>>>> /usr/lib/gcc/x86_64-pc-linux-gnu/6.1.0/../../../../x86_64-pc-linux-gn
>>>>>>>> u
>>>>>>>> /b
>>>>>>>> in
>>>>>>>> /ld: -r and - shared may not be used together
>>>>>>>> collect2: error: ld returned 1 exit status
>>>>>>>> Makefile:26993: recipe for target 'trig.module' failed
>>>>>>>>
>>>>>>>>
>>>>>>>> 2016-05-21  Magnus Granberg  <address@hidden>
>>>>>>>>
>>>>>>>>        acinclude.m4: Add check for -no-pie.    configure.ac: Add 
>>>>>>>> -no-pie to
>>>>>>>>
>>>>>>>> TARGET_LDFLAGS if needed.
>>>>>>>> ...
>>>>>>>
>>>>>>> Please test with current master:
>>>>>>>
>>>>>>> commit f4d35d49e32c29183b3492da18ea480d91716efe
>>>>>>> Author: Andrei Borzenkov <address@hidden>
>>>>>>> Date:   Tue Mar 22 20:12:22 2016 +0300
>>>>>>>
>>>>>>>     configure: set -fno-pie together with -fno-PIE
>>>>>>
>>>>>> Still fail the same way
>>>>>
>>>>> Please send full config.log and output of make.
>>>>
>>>> Gcc 6.1 pass -pie to the linker if is configure with --enable-default-pie
>>>> When linking with -r it don't mix well with -pie/-shared
>>>> Gentoo bug https://bugs.gentoo.org/show_bug.cgi?id=583042 with logs
>>>> Patch updated
>>>
>>> Any progres on this?
>>
>> My apologies. Do we really need any explicit check for this? As far as I
>> can tell, options -fpie, -fPIE, -pie appeared in the same GCC release
>> (at least they first mentioned in 3.4 documentation together). Manual
>> also says that -fpie/-fPIE and -pie must be used together.
>>
> https://gcc.gnu.org/gcc-6/changes.html (Other significant improvements)
> gcc 6.x is the only compiler that can enable -fPIE -pie as default
> without passing it on the command line. Debian/Ubuntu are testing to use this 
> as we do in Gentoo hardened. we allready disable -fPIE if needed but not -pie
> 
>> We do use $CC for linker - at least, by default. So it appears we should
>> be able to simply set -no-pie, no?
>>
> Is only gcc 6.X and newer linker that support -no-pie.
>  
>> Does clang support -fpie/-fPIE/-(no-)pie options? I do not see them in
>> help output, but it does not say much.
>>
> Clang support -fPIE/-fpie but i don't know if it support -no-pie
>> Oh, BTW, you have typo in patch
>>
>>> +[AC_MSG_CHECKING([whether linker accepts -no-pie])
>>> +AC_CACHE_VAL(grub_cv_cc_ld_nopie,
>>
>>                               ^^^^^
>>
>>> +[save_LDFLAGS="$LDFLAGS"
>>> +LDFLAGS="$LDFLAGS -no-pie"
>>> +AC_LINK_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
>>> +          [grub_cv_cc_ld_no_pie=yes],
>>> +          [grub_cv_cc_ld_no_pie=no])
>>
>>                               ^^^^^^
> Fixed in the updated patch
> 
> 2016-11-08  Magnus Granberg  <address@hidden>
> 
>       * acinclude.m4: Add check for -no-pie.
>       * configure.ac: Add -no-pie to TARGET_LDFLAGS if needed.
> 
> 
> 
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