Re: [RFC PATCH] binfmt_elf: Fix PIE execution with randomizationdisabled

[Jiri Kosina]

On Thu, 29 Sep 2011, Josh Boyer wrote:

> Perhaps another check here for randomize?  Something like:
> 
> #if defined(CONFIG_X86) || defined(CONFIG_ARM)
> 		if (current->flags & PF_RANDOMIZE)
> 			load_bias = 0;
> 		else if (vaddr)
> 			load_bias = 0;
> 		else
> 			load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE);
> #else
> 		load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
> #endif
> 
> If that's stupid, then feel free to tell me.  I won't pretend like I
> understand what is going on here yet, but based on the explanation you
> provided that might work.

I have just verified my hunch that the original patch from H.J. / Josh 
breaks ASLR completely, so Andrew, please drop it for now.

I am now looking into how to fix things properly.

Josh, looking at what you are proposing -- do you see any reason to make 
the behavior different in #else branch and in !(current->flags & 
PF_RANDOMIZE) case?

-- 
Jiri Kosina
SUSE Labs
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