[PATCH] Allow memset local PLT reference for RISC-V.

[H.J. Lu]

On Fri, Jul 10, 2020 at 2:45 PM Alistair Francis via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> On Tue, Jun 30, 2020 at 5:45 PM Maciej W. Rozycki via Libc-alpha
> <libc-alpha@sourceware.org> wrote:
> >
> > On Mon, 29 Jun 2020, Jim Wilson wrote:
> >
> > > Anyways, if you want to know where the PLT call is coming from, you
> > > can't rely on the relocs.  R_RISCV_CALL_PLT is not necessarily a plt
> > > call.
> >
> >  If a PLT entry has been created, then the linker must have considered the
> > symbol referred preemptible, whether legitimately or not.
> >
> >  Rather than scratching one's head I would suggest running the relevant LD
> > invocation under GDB to find out what really happens there, which may be
> > as easy as setting a breakpoint on `riscv_elf_finish_dynamic_symbol' with
> > the right condition on the hash entry so as to stop on `memset' only, and
> > then working backwards with a watchpoint (on a host system that does not
> > use ASLR) to find out what sets `h->plt.offset'.  There'll be the answer.
>
> I tried to look into this but haven't made much progress here. If
> anyone has more ideas they would be very welcome otherwise I'll keep
> digging into this.
>

It may be related to:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67220


--
H.J.