x86_64 / i686 no-PIE failures

[Szabolcs Nagy]

The 11/04/2022 08:12, Florian Weimer via Libc-alpha wrote:
> * Joseph Myers:
> 
> > Now that the uchar.h failures with mainline GCC are fixed, other failures 
> > show up for x86_64 / i686 no-PIE with mainline GCC and binutils (I don't 
> > know how long these have been there):
> >
> > /scratch/jmyers/glibc-bot/install/compilers/x86_64-linux-gnu/lib/gcc/x86_64-glibc-linux-gnu/13.0.0/../../../../x86_64-glibc-linux-gnu/bin/ld: /scratch/jmyers/glibc-bot/build/glibcs/x86_64-linux-gnu-no-pie/glibc/elf/ifuncmain1.o: non-canonical reference to canonical protected function `foo_protected' in /scratch/jmyers/glibc-bot/build/glibcs/x86_64-linux-gnu-no-pie/glibc/elf/ifuncmod1.so
> > /scratch/jmyers/glibc-bot/install/compilers/x86_64-linux-gnu/lib/gcc/x86_64-glibc-linux-gnu/13.0.0/../../../../x86_64-glibc-linux-gnu/bin/ld: failed to set dynamic section sizes: bad value
> > collect2: error: ld returned 1 exit status
> > ../Rules:238: recipe for target '/scratch/jmyers/glibc-bot/build/glibcs/x86_64-linux-gnu-no-pie/glibc/elf/ifuncmain1' failed
> > make[3]: *** [/scratch/jmyers/glibc-bot/build/glibcs/x86_64-linux-gnu-no-pie/glibc/elf/ifuncmain1] Error 1
> > make[3]: Leaving directory '/scratch/jmyers/glibc-bot/src/glibc/elf'
> 
> H.J.,
> 
> this test no longer seems valid with current binutils (or current
> binutils is broken).
> 
> ifuncmain1.o has X86_64_32S and X86_64_PLT32 relocations for
> foo_protected, so the main program must contain a PLT stub for
> foo_protected.  Apparently, ld no longer produces such binaries.
> 
> What should we do about this?

aarch64 has the same issue since

  binutils commit 90b7a5df152a64d2bea20beb438e8b81049a5c30
  aarch64: Disallow copy relocations on protected data

which should be in the binutils 2.39 release

ld.lld rejects such usage too, i think the plan was to not
support extern protected symbol refs with canonical address
moved to the main exe.

so the tests should be changed, but i'm not sure what's
the best approach (completely dropping protected or just
ensure the address is not taken in no-pie case).