[PATCH] D20024: [ELF] - Protect first entries of got.plt with RelRo.

[Rafael Espíndola via llvm-commits]

OK, I will add a test for it.
On May 9, 2016 1:40 PM, "Rui Ueyama" <ruiu at google.com> wrote:

> I think my take is that as this is clearly documented in the x86-64 psABI,
> we should keep it even if it seems redundant/useless.
>
> On Mon, May 9, 2016 at 8:54 AM, H.J. Lu <hjl.tools at gmail.com> wrote:
>
>> On Mon, May 9, 2016 at 8:51 AM, H.J. Lu <hjl.tools at gmail.com> wrote:
>> > On Mon, May 9, 2016 at 8:46 AM, Rafael Espíndola
>> > <rafael.espindola at gmail.com> wrote:
>> >> I was able to link and run the musl  dynamic linker with the patch that
>> >> stops setting got[0].
>> >>
>> >> So, Rui, what is your take on this? Should we leave that out of tree
>> until
>> >> it is time to try to link glibc's dynamic linker?
>> >>
>> >
>> > If you do so, please state clearly that your linker doesn't follow
>> > x86-64 psABI which says:
>> >
>> > The tables first entry (number zero) is reserved to hold the address of
>> the dy-
>> > namic structure, referenced with the symbol _DYNAMIC. This allows a
>> program,
>> > such as the dynamic linker, to find its own dynamic structure without
>> having yet
>> > processed its relocation entries. This is especially important for the
>> dynamic
>> > linker, because it must initialize itself without relying on other
>> > programs to re-
>> > locate its memory image.
>>
>> BTW, you also need to change the first entry of PLT to use
>> GOT[0] and GOT[1] instead of GOT[1] and GOT[2].
>>
>> --
>> H.J.
>>
>
>
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