Re: [PATCH] [RESEND] PIE executable randomization

[Chuck Ebbert <cebbert@redhat.com>]

On 08/14/2007 04:41 PM, Jiri Kosina wrote:
> (added Arjan to CC, as he has been working on the kernel part of the 
> randomization previously)
> 
> On Tue, 14 Aug 2007, Jakub Jelinek wrote:
> 
>> If I'm reading the above hunk correctly, this means we will randomize 
>> all PIEs and even all dynamic linkers invoked as executables on i?86 and 
>> x86_64, and on the rest of arches we won't randomize at all, instead 
>> load ET_DYN objects at ELF_ET_DYN_BASE address. But I don't see anything 
>> i?86/x86_64 specific on this.
> 
> Hi Jakub,
> 
> actually, it is currently arch-specific, and that's because of different 
> memory layouts on different archs.
> 
> It turned out recently that PIE-compiled binaries on x86_64, that perform 
> larger amount of brk-allocations (for example bash) will not work (but 
> they will work on ?86). This is because currently on ?86 the memory layout 
> is as follows:

But your patch is enabling randomization for x86_64, because CONFIG_X86
includes both 32 and 64 bit archs.