PR32387 ppc64 TLS optimization bug with -fno-plt code

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.

diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 9674fcdd6be76dc9deb2af7204424b724da871e3..f7debc1edbc46e593292e3c89800c14f6f228fd3 100644 (file)
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -4915,6 +4915,15 @@ ppc64_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
       tls_type = 0;
       switch (r_type)
        {
+       case R_PPC64_PLTSEQ:
+       case R_PPC64_PLTSEQ_NOTOC:
+         /* Inline plt call code emitted by gcc doesn't support
+            modifying the tls_index words to short-circuit
+            __tls_get_addr calls.  See PR32387.  */
+         if (h != NULL && (h == tga || h == dottga))
+           htab->params->tls_get_addr_opt = 0;
+         break;
+
        case R_PPC64_TLSGD:
        case R_PPC64_TLSLD:
          /* These special tls relocs tie a call to __tls_get_addr with