Re: [PATCH v6 02/27] x86: Use symbol name in jump table for PIE support

From: Thomas Garnier
Date: Thu Feb 07 2019 - 18:55:52 EST


On Thu, Feb 7, 2019 at 9:11 AM Borislav Petkov <bp@xxxxxxxxx> wrote:
>
> On Thu, Feb 07, 2019 at 09:04:45AM -0800, Thomas Garnier wrote:
> > I assume that's an optimisation done by gcc later.
>
> So why is that change even needed? Where does it break?
>
> > The P modifier in the documentation does state that it is used to
> > generate PIC code.
>
> The documentation says:
>
> "If used for a function, print the PLT suffix and generate PIC code. For
> example, emit foo@PLT instead of âfooâ for the function foo()."
>
> when you use %P for a function. Which is not how it is used here.

I did more checks about that. I think Ard's patch to make jump label
relative actually fixed the issue I had with them.

Thanks for spotting this, I will do additional checks and look at
removing this change.

>
> --
> Regards/Gruss,
> Boris.
>
> Good mailing practices for 400: avoid top-posting and trim the reply.