[PATCH] Fix offset2lib issue for x86*, ARM*, PowerPC and MIPS

[Kees Cook]

On Thu, Feb 26, 2015 at 4:11 PM, Kees Cook <keescook at chromium.org> wrote:
> On Thu, Feb 26, 2015 at 4:06 PM, Andrew Morton
> <akpm at linux-foundation.org> wrote:
>> On Thu, 26 Feb 2015 15:37:37 -0800 Kees Cook <keescook at chromium.org> wrote:
>>
>>> Agh, no, please let's avoid the CONFIG addition.
>>
>> That is precisely how we do this.
>>
>>> Hector mentioned in private mail that he was looking at an alternative
>>> that adds exec_base to struct mm which would avoid all this insanity.
>>>
>>> Can't we do something like:
>>>
>>> #ifndef mmap_rnd
>>> # define mmap_rnd 0
>>> #endif
>>
>> Sure, and sprinkle
>>
>> #define mmap_rnd mmap_rnd
>>
>> in five arch header files where nobody thinks to look.
>>
>> For better or for worse, we are consolidating such things into arch/*/Kconfig.
>
> Okay, fair enough. Even with your configs (though shouldn't they be
> ARCH_HAS or just HAVE?) I've now stumbled over the issue that we can't
> put randomize_et_dyn in binfmt_elf because it conflicts with linking
> against compat_binfmt_elf.

Instead of all this, how about we rework the existing CONFIG and just
change around how s390 does this to match the other architectures and
remove the ifdef in binfmt_elf.c at the same time? Let me work
something up...

-Kees

-- 
Kees Cook
Chrome OS Security