Re: [PATCH v2 1/5] objtool: Deal with relative jump tables correctly

[Peter Zijlstra <peterz@infradead.org>]

On Thu, Oct 10, 2024 at 03:59:43PM +0200, Ard Biesheuvel wrote:
> On Thu, 10 Oct 2024 at 15:26, Peter Zijlstra <peterz@infradead.org> wrote:
> >
> > On Thu, Oct 10, 2024 at 02:28:03PM +0200, Ard Biesheuvel wrote:
> > > diff --git a/tools/objtool/check.c b/tools/objtool/check.c
> > > index 3cb3e9b5ad0b..7f7981a93535 100644
> > > --- a/tools/objtool/check.c
> > > +++ b/tools/objtool/check.c
> > > @@ -2101,6 +2101,8 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
> > >  {
> > >       struct symbol *pfunc = insn_func(insn)->pfunc;
> > >       struct reloc *table = insn_jump_table(insn);
> > > +     unsigned int rtype = reloc_type(table);
> > > +     bool pcrel = rtype == R_X86_64_PC32;
> >
> > R_DATA32 or R_TEXT32 please, the budding cross arch stuff has their own
> > names for all that.
> >
> 
> #define R_DATA32        R_X86_64_PC32
> #define R_DATA64        R_X86_64_PC32
> #define R_TEXT32        R_X86_64_PC32
> #define R_TEXT64        R_X86_64_PC32
> 
> Clear as mud.
> 
> I'd guess we need the '64' variant here, but I'm not sure which one to
> use for a .rodata relocation pointing to .text. Any hints?

Josh? do R_{DATA,TEXT}64 want to be _PC64 ?