powerpc: Fix Text randomization

Vineeth Vijayan vvijayan at mvista.com
Fri Nov 14 16:33:30 AEDT 2014


ping !

any update on this ? As i understand, only powerpc and s390 uses the
randomize_et_dyn call; for all other architecture this is an obsolete
function call.

this call for another patch where randomize_et_dyn is removed.

On Wed, Oct 15, 2014 at 12:08 PM, Vineeth Vijayan <vvijayan at mvista.com> wrote:
> On Wed, Oct 15, 2014 at 7:38 AM, Michael Ellerman <mpe at ellerman.id.au> wrote:
>> On Fri, 2014-10-10 at 05:45:26 UTC, Vineeth Vijayan wrote:
>>> Right now there is no way to disable TEXT randomization on a PPC32
>>> machine. text randomization happens even in the case of "echo 0 >
>>> /proc/sys/kernel/randomize_va_space"
>>
>> Yeah it seems to happen on ppc64 too.
>>
>>> This happens due to the incorrect definition of ELF_ET_DYN_BASE at
>>> arch/powerpc/include/asm/elf.h
>>
>> What is incorrect about it? We are not the only arch that does that.
>>
>
> I think we are one of the arch which does it.
> The same has been tested on x86 and arm, where ELF_ET_DYN_BASE doesn’t
> use randomize_et_dyn call, and it works properly as per the user-space
> definition of randomization;
>
> (i.e when at "echo 0 > /proc/sys/kernel/randomize_va_space", TEXT
> randomization should not happen.)
>
>> I'm not clear on what has changed to break this?
>>
>> cheers


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