[binutils-gdb] __tls_get_addr_opt stubs and tocsave optimization

[Alan Modra <amodra at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=e81b4c933c1b88e29f4b27627dd9ea0bf9189944

commit e81b4c933c1b88e29f4b27627dd9ea0bf9189944
Author: Alan Modra <amodra@gmail.com>
Date:   Sun Aug 5 19:44:03 2018 +0930

    __tls_get_addr_opt stubs and tocsave optimization
    
    This patch fixes a bug in the handling of the __tls_get_addr_opt
    stub.  Calls via this stub don't have a toc restoring instruction
    following the "bl", and the stub itself doesn't have an initial toc
    save instruction.  Thus it is incorrect to skip over the first
    instruction when a __tls_get_addr call is marked with a tocsave
    reloc.
    
    	* elf64-ppc.c (ppc64_elf_relocate_section): Don't skip first
    	instruction of __tls_get_addr_opt stub.
    	(plt_stub_size): Omit ALWAYS_EMIT_R2SAVE condition when
    	dealing with __tls_get_addr_opt stub.
    	(build_tls_get_addr_stub, ppc_size_one_stub): Likewise.

Diff:
---
 bfd/ChangeLog   |  8 ++++++++
 bfd/elf64-ppc.c | 13 +++++++------
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index b12e024..b8fd5be 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,11 @@
+2018-08-07  Alan Modra  <amodra@gmail.com>
+
+	* elf64-ppc.c (ppc64_elf_relocate_section): Don't skip first
+	instruction of __tls_get_addr_opt stub.
+	(plt_stub_size): Omit ALWAYS_EMIT_R2SAVE condition when
+	dealing with __tls_get_addr_opt stub.
+	(build_tls_get_addr_stub, ppc_size_one_stub): Likewise.
+
 2018-08-06  Claudiu Zissulescu  <claziss@synopsys.com>
 
 	* elf32-arc.c (arc_elf_merge_private_bfd_data): Complain about
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 008d352..5e20bbd 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -11027,8 +11027,7 @@ plt_stub_size (struct ppc_link_hash_table *htab,
       && htab->params->tls_get_addr_opt)
     {
       size += 7 * 4;
-      if (ALWAYS_EMIT_R2SAVE
-	  || stub_entry->stub_type == ppc_stub_plt_call_r2save)
+      if (stub_entry->stub_type == ppc_stub_plt_call_r2save)
 	size += 6 * 4;
     }
   return size;
@@ -11273,8 +11272,7 @@ build_tls_get_addr_stub (struct ppc_link_hash_table *htab,
   bfd_put_32 (obfd, MR_R3_R0, p),		p += 4;
   if (r != NULL)
     r[0].r_offset += 7 * 4;
-  if (!ALWAYS_EMIT_R2SAVE
-      && stub_entry->stub_type != ppc_stub_plt_call_r2save)
+  if (stub_entry->stub_type != ppc_stub_plt_call_r2save)
     return build_plt_stub (htab, stub_entry, p, offset, r);
 
   bfd_put_32 (obfd, MFLR_R11, p),		p += 4;
@@ -11928,8 +11926,7 @@ ppc_size_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
 	      && (stub_entry->h == htab->tls_get_addr_fd
 		  || stub_entry->h == htab->tls_get_addr)
 	      && htab->params->tls_get_addr_opt
-	      && (ALWAYS_EMIT_R2SAVE
-		  || stub_entry->stub_type == ppc_stub_plt_call_r2save))
+	      && stub_entry->stub_type == ppc_stub_plt_call_r2save)
 	    stub_entry->group->tls_get_addr_opt_bctrl
 	      = stub_entry->stub_offset + size - 5 * 4;
 
@@ -15336,6 +15333,10 @@ ppc64_elf_relocate_section (bfd *output_bfd,
 		    && ALWAYS_EMIT_R2SAVE)
 		   || stub_entry->stub_type == ppc_stub_plt_call_r2save
 		   || stub_entry->stub_type == ppc_stub_plt_call_both)
+		  && !(h != NULL
+		       && (h == htab->tls_get_addr_fd
+			   || h == htab->tls_get_addr)
+		       && htab->params->tls_get_addr_opt)
 		  && rel + 1 < relend
 		  && rel[1].r_offset == rel->r_offset + 4
 		  && ELF64_R_TYPE (rel[1].r_info) == R_PPC64_TOCSAVE)