Dynamic TLS section symbols

It is possible to create shared libraries on PowerPC using
-ftls-model=inital-exec or -ftls-model=local-exec.  The first is half
reasonable, getting you a shared library that can't be dlopen'd but
otherwise is reasonable.  The second is quite bad.  Not only do you
lose being able to dlopen, the library also has dynamic text
relocations.  Worse, the TPREL16_LO, TPREL16_HA and other TPREL16
dynamic relocs emitted were wrong, resulting in wrong values being
applied by ld.so.

Using the first TLS section symbol in dynamic relocations for local
TLS symbols doesn't work.  It's wrong because TLS symbols used by TLS
relocs have values relative to the TLS segment, whereas the TLS
section symbols are addresses.  This patch instead uses a symbol index
of zero which is used elsewhere by PowerPC on dynamic TLS relocs.
It's not strictly ABI compliant to use a non-TLS symbol with TLS
relocs but symbol index zero can be interpreted as "no symbol".  Not
using the first TLS section symbol means it doesn't need to be dynamic.

The patch also fixes a further problem with PowerPC32 dynamic TPREL16*
relocs, which shouldn't have the symbol value in the addend as we do
for non-TLS symbols.

bfd/
	* elflink.c (_bfd_elf_omit_section_dynsym_default): Don't keep
	tls_sec.
	(_bfd_elf_init_1_index_section): Prefer not using TLS sections.
	(_bfd_elf_init_2_index_sections): Likewise.
	* elf64-ppc.c (ppc64_elf_relocate_section): When emitting dynamic
	relocations for local TLS symbols, use STN_UNDEF as the relocation
	symbol.
	* elf32-ppc.c (ppc_elf_relocate_section): Likewise, and don't
	leave TLS symbol value in the addend.
ld/
	* testsuite/ld-powerpc/tlsso.r: Update.
	* testsuite/ld-powerpc/tlsso32.g: Update.
	* testsuite/ld-powerpc/tlsso32.r: Update.
	* testsuite/ld-powerpc/tlstocso.r: Update.
	* testsuite/ld-cris/tls-dso-dtpoffd2.d: Update.
	* testsuite/ld-cris/tls-dso-dtpoffd4.d: Update.
	* testsuite/ld-cris/tls-dso-tpoffgotcomm1.d: Update.
	* testsuite/ld-cris/tls-gd-1.d: Update.
	* testsuite/ld-cris/tls-gd-1h.d: Update.
	* testsuite/ld-cris/tls-gd-2.d: Update.
	* testsuite/ld-cris/tls-gd-2h.d: Update.
	* testsuite/ld-cris/tls-ie-10.d: Update.
	* testsuite/ld-cris/tls-ie-11.d: Update.
	* testsuite/ld-cris/tls-ie-8.d: Update.
	* testsuite/ld-cris/tls-ie-9.d: Update.
	* testsuite/ld-cris/tls-js1.d: Update.
	* testsuite/ld-cris/tls-ld-4.d: Update.
	* testsuite/ld-cris/tls-ld-5.d: Update.
	* testsuite/ld-cris/tls-ld-6.d: Update.
	* testsuite/ld-cris/tls-ld-7.d: Update.
	* testsuite/ld-cris/tls-ldgd-14.d: Update.
	* testsuite/ld-cris/tls-ldgd-15.d: Update.
	* testsuite/ld-cris/tls-ldgdx-14.d: Update.
	* testsuite/ld-cris/tls-ldgdx-15.d: Update.
	* testsuite/ld-cris/tls-local-54.d: Update.
	* testsuite/ld-cris/tls-local-60.d: Update.
	* testsuite/ld-cris/tls-local-61.d: Update.
	* testsuite/ld-cris/tls-local-63.d: Update.
	* testsuite/ld-cris/tls-local-64.d: Update.
	* testsuite/ld-cris/tls-ok-30.d: Update.
	* testsuite/ld-cris/tls-ok-32.d: Update.
	* testsuite/ld-cris/tls-ok-34.d: Update.
	* testsuite/ld-mips-elf/tls-multi-got-1.got: Update.
	* testsuite/ld-mips-elf/tls-multi-got-1.r: Update.
	* testsuite/ld-mips-elf/tlsdyn-pie-o32.d: Update.
	* testsuite/ld-mips-elf/tlsdyn-pie-o32.got: Update.
	* testsuite/ld-mips-elf/tlslib-o32-hidden.got: Update.
	* testsuite/ld-mips-elf/tlslib-o32-ver.got: Update.
	* testsuite/ld-mips-elf/tlslib-o32.got: Update.
	* testsuite/ld-s390/tlspic.rd: Update.
	* testsuite/ld-s390/tlspic_64.rd: Update.
	* testsuite/ld-sparc/tlssunnopic32.rd: Update.
	* testsuite/ld-sparc/tlssunnopic64.rd: Update.
	* testsuite/ld-sparc/tlssunpic32.rd: Update.
	* testsuite/ld-sparc/tlssunpic64.rd: Update.

1 files changed, 11 insertions, 11 deletions

diff --git a/ld/testsuite/ld-cris/tls-gd-1.d b/ld/testsuite/ld-cris/tls-gd-1.d
index 30ab7ef..4fbd79c 100644
--- a/ld/testsuite/ld-cris/tls-gd-1.d
+++ b/ld/testsuite/ld-cris/tls-gd-1.d
@@ -12,21 +12,21 @@
 
 Program Header:
     LOAD off    0x0+ vaddr 0x0+ paddr 0x0+ align 2\*\*13
-         filesz 0x0+144 memsz 0x0+144 flags r-x
-    LOAD off    0x0+144 vaddr 0x0+2144 paddr 0x0+2144 align 2\*\*13
+         filesz 0x0+130 memsz 0x0+130 flags r-x
+    LOAD off    0x0+130 vaddr 0x0+2130 paddr 0x0+2130 align 2\*\*13
          filesz 0x0+108 memsz 0x0+108 flags rw-
- DYNAMIC off    0x0+1c8 vaddr 0x0+21c8 paddr 0x0+21c8 align 2\*\*2
+ DYNAMIC off    0x0+1b4 vaddr 0x0+21b4 paddr 0x0+21b4 align 2\*\*2
          filesz 0x0+70 memsz 0x0+70 flags rw-
-     TLS off    0x0+144 vaddr 0x0+2144 paddr 0x0+2144 align 2\*\*2
+     TLS off    0x0+130 vaddr 0x0+2130 paddr 0x0+2130 align 2\*\*2
          filesz 0x0+84 memsz 0x0+84 flags r--
 
 Dynamic Section:
   HASH                 0x0+b4
-  STRTAB               0x0+124
-  SYMTAB               0x0+d4
+  STRTAB               0x0+110
+  SYMTAB               0x0+d0
   STRSZ                0x0+d
   SYMENT               0x0+10
-  RELA                 0x0+134
+  RELA                 0x0+120
   RELASZ               0x0+c
   RELAENT              0x0+c
 private flags = 0:
@@ -42,13 +42,13 @@ DYNAMIC SYMBOL TABLE:
 
 DYNAMIC RELOCATION RECORDS
 OFFSET   TYPE              VALUE 
-0+2244 R_CRIS_DTP        x
+0+2230 R_CRIS_DTP        x
 
 Contents of section \.hash:
 #...
 Contents of section \.text:
- 0140 5fae0c00                             .*
+ 012c 5fae0c00                             .*
 #...
 Contents of section \.got:
- 2238 c8210+ 0+ 0+ 0+  .*
- 2248 0+                             .*
+ 2224 b4210+ 0+ 0+ 0+  .*
+ 2234 0+                             .*