[PATCH 1/6] ld: don't generate base relocations in PE output for absolute symbols

[Alan Modra]

On Thu, Mar 04, 2021 at 09:52:06AM +0100, Jan Beulich wrote:
> On 04.03.2021 05:46, Alan Modra wrote:
> > On Tue, Mar 02, 2021 at 10:47:03AM +0100, Jan Beulich via Binutils wrote:
> >> It is the very nature of absolute symbols that they don't change even
> >> if the loader decides to put the image at other than its link-time base
> >> address. Of the linker-defined (and PE-specific) symbols __image_base__
> >> (and its alias) needs special casing, as it'll still appear to be
> >> absolute at this point.
> >>
> >> A new inquiry function in ldexp.c is needed because PE base relocations
> >> get generated before ldexp_finalize_syms() runs, yet whether a
> >> relocation is needed depends on the ultimate property of a symbol.
> >>
> >> ld/
> >> 2021-02-XX  Jan Beulich  <jbeulich@suse.com>
> >>
> >> 	* ldexp.c (ldexp_is_final_sym_absolute): New.
> >> 	* ldexp.h (ldexp_is_final_sym_absolute): Declare.
> >> 	* pe-dll.c (generate_reloc): Skip absolute symbols.
> > 
> > OK.
> 
> Just to confirm - subsequently I did send a test case to be added
> here, for which I have these additional entries:

Yes, that's fine too.

> 	* testsuite/ld-pe/reloc.s, testsuite/ld-pe/reloc.d: New.
> 	* testsuite/ld-pe/pe.exp: Run new test.
> 
> Is that okay to commit as a whole, or should I re-submit (or
> submit the test case addition as a separate change)?
> 
> >> +		  /* Nor for absolute symbols.  */
> >> +		  else if (blhe && ldexp_is_final_sym_absolute (blhe)
> >> +			   && (!blhe->linker_def
> >> +			       || (strcmp(sym->name, "__image_base__")
> >> +				   && strcmp(sym->name, U ("__ImageBase")))))
> > 
> > Space after strcmp.
> 
> Oh, yes, sorry.
> 
> Jan

-- 
Alan Modra
Australia Development Lab, IBM