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Re: Relocations to use when eliding plts


On Thu, May 28, 2015 at 08:52:28AM -0700, Richard Henderson wrote:
> On 05/28/2015 08:42 AM, H.J. Lu wrote:
> > On Thu, May 28, 2015 at 8:29 AM, Richard Henderson <rth@redhat.com> wrote:
> >> On 05/28/2015 04:27 AM, H.J. Lu wrote:
> >>> You get consecutive jmpq's because x86 PLT entry is used as the
> >>> canonical function address.  If you compile main with -fno-plt -fPIE, you
> >>> get:
> >>
> >> Well, duh.  If the main executable has no PLTs, they aren't used as the
> >> canonical function address.  Surely you aren't proposing that as a solution?
> >>
> > 
> > I was just explaining where those consecutive jmpq's came from.
> > I wasn't suggesting a solution..
> 
> I did explain it.  In the quite long message.
> 
> No comments about the rest of it, wherein I suggest a solution that doesn't
> require the main executable to be compiled with -fno-plt in order to avoid them?

And even that wouldn't help, you'd need to compile the binaries with -fpie -fno-plt,
as -fno-plt doesn't affect normal non-PIC calls.

	Jakub


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