[PR,ld/22263,PR,ld/25056] arm: Avoid dynamic TLS relocs in PIE

Message ID 784785eb-42b3-e095-e136-de2a803e46ba@arm.com
State New
Headers show
Series
  • [PR,ld/22263,PR,ld/25056] arm: Avoid dynamic TLS relocs in PIE
Related show

Commit Message

Szabolcs Nagy Oct. 4, 2019, 9:38 a.m.
Fixes incorrect TLS relocs in pie and allows TLS relaxation in pie.

OK to commit and later backport?

Comments

Nick Clifton Oct. 4, 2019, 9:47 a.m. | #1
Hi Szabolcs,

> Fixes incorrect TLS relocs in pie and allows TLS relaxation in pie.

> 

> OK to commit and later backport?


Approved for both, please apply.

Cheers
  Nick

Patch

From 7d6e280a0f3b9978b0edb20173d067d071531a3d Mon Sep 17 00:00:00 2001
From: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date: Wed, 2 Oct 2019 19:46:46 +0100
Subject: [PATCH] [PR ld/22263][PR ld/25056] arm: Avoid dynamic TLS relocs in
 PIE

Dynamic relocs are only needed in an executable for TLS symbols if
those are defined in an external module and even then TLS access
can be relaxed to use IE model instead of GD.

Several bfd_link_pic checks are turned into bfd_link_dll checks
to fix TLS handling in PIE, for the same fix some other targets
used !bfd_link_executable checks, but that includes relocatable
objects so dll seems safer (in most cases either should work, since
dynamic relocations are not applied in relocatable objects).

On arm* fixes
FAIL: Build pr22263-1

bfd/
2019-10-02  Szabolcs Nagy  <szabolcs.nagy@arm.com>
	PR ld/22263
	PR ld/25056
	* elf32-arm.c (elf32_arm_tls_transition): Use bfd_link_dll instead of
	bfd_link_pic for TLS checks.
	(elf32_arm_final_link_relocate): Likewise.
	(allocate_dynrelocs_for_symbol): Likewise.
---
 bfd/elf32-arm.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/bfd/elf32-arm.c b/bfd/elf32-arm.c
index bb53e039e3..451949d278 100644
--- a/bfd/elf32-arm.c
+++ b/bfd/elf32-arm.c
@@ -4914,7 +4914,7 @@  elf32_arm_tls_transition (struct bfd_link_info *info, int r_type,
 {
   int is_local = (h == NULL);
 
-  if (bfd_link_pic (info)
+  if (bfd_link_dll (info)
       || (h && h->root.type == bfd_link_hash_undefweak))
     return r_type;
 
@@ -11700,7 +11700,7 @@  elf32_arm_final_link_relocate (reloc_howto_type *	    howto,
 	  {
 	    /* If we don't know the module number, create a relocation
 	       for it.  */
-	    if (bfd_link_pic (info))
+	    if (bfd_link_dll (info))
 	      {
 		Elf_Internal_Rela outrel;
 
@@ -11804,7 +11804,7 @@  elf32_arm_final_link_relocate (reloc_howto_type *	    howto,
 	       now, and emit any relocations.  If both an IE GOT and a
 	       GD GOT are necessary, we emit the GD first.  */
 
-	    if ((bfd_link_pic (info) || indx != 0)
+	    if ((bfd_link_dll (info) || indx != 0)
 		&& (h == NULL
 		    || (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
 			&& !resolved_to_zero)
@@ -11821,7 +11821,7 @@  elf32_arm_final_link_relocate (reloc_howto_type *	    howto,
 		/* We should have relaxed, unless this is an undefined
 		   weak symbol.  */
 		BFD_ASSERT ((h && (h->root.type == bfd_link_hash_undefweak))
-			    || bfd_link_pic (info));
+			    || bfd_link_dll (info));
 		BFD_ASSERT (globals->sgotplt_jump_table_size + offplt + 8
 			    <= globals->root.sgotplt->size);
 
@@ -16494,7 +16494,7 @@  allocate_dynrelocs_for_symbol (struct elf_link_hash_entry *h, void * inf)
 	    indx = h->dynindx;
 
 	  if (tls_type != GOT_NORMAL
-	      && (bfd_link_pic (info) || indx != 0)
+	      && (bfd_link_dll (info) || indx != 0)
 	      && (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
 		  || h->root.type != bfd_link_hash_undefweak))
 	    {
-- 
2.17.1