PR32387 ppc64 TLS optimization bug with -fno-plt code

[Peter Bergner]

On 11/26/24 4:53 AM, Alan Modra wrote:
> The inline plt code emitted by gcc is incompatible with the
> linker/ld.so --tls-get-addr-optimize scheme.  This is the runtime
> optimisation where the first call to __tls_get_addr results in
> __tls_get_addr updating the tls_index pair, then the special linker
> stub using that to short-circuit second and subsequent calls for a
> given tls symbol.  Enabled by default when the linker sees
> __tls_get_addr_opt is preseent, and enabled in ld.so when DT_PPC64_OPT
> has PPC64_OPT_TLS set.  Note that this is distinct from link-time tls
> optimisation.
> 
> 	PR 32387
> 	* elf64-ppc.c (ppc64_elf_check_relocs): Disable tls_get_addr_opt
> 	on detecting inline plt calls to __tls_get_addr.

Thanks for the fix Alan!

Is this something we want back ported to one or more of the release branches?
I can do the backports if you just let me know how far back you want the
fix to go.

Peter