Messages in this thread | | | Date | Mon, 9 Dec 2013 22:51:18 +0100 (CET) | From | Jiri Kosina <> | Subject | Re: [PATCH] binfmt_elf: fix PIE load with randomization disabled |
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On Mon, 9 Dec 2013, H.J. Lu wrote:
> >> No, please don't do that. Normally, PIE has zero load address and kernel > >> can load it anywhere. There are multiple reasons why PIE has non-zero > >> load address. Saying you need to load a program above 4GB under x86-64, > >> you can't do that with normal dynamic executable. PIE with non-zero load > >> address is the only way to do that on x86-64. > > > > Hmm, so if it's because of 4G PT_LOAD limit, how about at least adding > > Yes. > > > randomized offset to the supplied vaddr? > > Yes, people who build PIE with non-zero vaddr can use > randomized vaddr.
I don't follow you here. Do you suggest compile-time randomzation?
> > PT_LOAD being non-zero causing randomization to be turned off seems like > > quite unexpected behavior to me, with a great potential to cause a lot of > > confusion. > > > > There should be no difference between dynamic executable and PIE > with non-zero vaddr when choosing where to load them.
Could you please elaborate why do you think this statement is true?
Thanks,
-- Jiri Kosina SUSE Labs
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