[PATCH] ld/ARM: Fix IFUNC and TLS descriptors in the same shared object

[Will Newton <will.newton@linaro.org>]

Combining TLS descriptors and GNU indirect functions in the same
object could lead to assertions or multiple dynamic relocations
for the same GOT slot. Fix the bookkeeping so this doesn't happen.

This allows building and make checking glibc with -mtls-dialect=gnu2.

bfd/ChangeLog:

2014-05-21  Will Newton  <will.newton@linaro.org>

	* elf32-arm.c (elf32_arm_allocate_plt_entry): Increment
	htab->next_tls_desc_index in the non-IPLT case.
	Calculate GOT offset correctly for the non-IPLT case.
	(allocate_dynrelocs_for_symbol): Don't increment
	htab->next_tls_desc_index here.

ld/testsuite/ChangeLog:

2014-05-21  Will Newton  <will.newton@linaro.org>

	* ld-arm/arm-elf.exp: Add ifunc-gdesc test.
	* ld-arm/ifunc-gdesc.r: New file.
	* ld-arm/ifunc-gdesc.s: Likewise.
	* ld-arm/ifunc-gdesc.ver: Likewise.
---
 bfd/elf32-arm.c                     |  9 ++++++---
 ld/testsuite/ld-arm/arm-elf.exp     |  3 +++
 ld/testsuite/ld-arm/ifunc-gdesc.r   |  6 ++++++
 ld/testsuite/ld-arm/ifunc-gdesc.s   | 29 +++++++++++++++++++++++++++++
 ld/testsuite/ld-arm/ifunc-gdesc.ver |  4 ++++
 5 files changed, 48 insertions(+), 3 deletions(-)
 create mode 100644 ld/testsuite/ld-arm/ifunc-gdesc.r
 create mode 100644 ld/testsuite/ld-arm/ifunc-gdesc.s
 create mode 100644 ld/testsuite/ld-arm/ifunc-gdesc.ver

diff --git a/bfd/elf32-arm.c b/bfd/elf32-arm.c
index 526d4f8..6a20baf 100644
--- a/bfd/elf32-arm.c
+++ b/bfd/elf32-arm.c
@@ -7521,6 +7521,8 @@ elf32_arm_allocate_plt_entry (struct bfd_link_info *info,
 	 first entry.  */
       if (splt->size == 0)
 	splt->size += htab->plt_header_size;
+
+      htab->next_tls_desc_index++;
     }
 
   /* Allocate the PLT entry itself, including any leading Thumb stub.  */
@@ -7533,7 +7535,10 @@ elf32_arm_allocate_plt_entry (struct bfd_link_info *info,
     {
       /* We also need to make an entry in the .got.plt section, which
 	 will be placed in the .got section by the linker script.  */
-      arm_plt->got_offset = sgotplt->size - 8 * htab->num_tls_desc;
+      if (is_iplt_entry)
+	arm_plt->got_offset = sgotplt->size;
+      else
+	arm_plt->got_offset = sgotplt->size - 8 * htab->num_tls_desc;
       sgotplt->size += 4;
     }
 }
@@ -13359,8 +13364,6 @@ allocate_dynrelocs_for_symbol (struct elf_link_hash_entry *h, void * inf)
 	      h->target_internal = ST_BRANCH_TO_ARM;
 	    }
 
-	  htab->next_tls_desc_index++;
-
 	  /* VxWorks executables have a second set of relocations for
 	     each PLT entry.  They go in a separate relocation section,
 	     which is processed by the kernel loader.  */
diff --git a/ld/testsuite/ld-arm/arm-elf.exp b/ld/testsuite/ld-arm/arm-elf.exp
index c255587..2e7e164 100644
--- a/ld/testsuite/ld-arm/arm-elf.exp
+++ b/ld/testsuite/ld-arm/arm-elf.exp
@@ -460,6 +460,9 @@ set armelftests_nonacl {
      "" {long-plt-format.s}
      {{objdump "-d -j .plt" long-plt-format.d}}
      "long-plt-format"}
+    {"IFUNC and TLS descriptor shared library" "-shared -T arm-lib.ld --version-script=ifunc-gdesc.ver" "" "" {ifunc-gdesc.s}
+     {{objdump "-Rw" ifunc-gdesc.r}}
+     "ifunc-gdesc.so"}
 }
 
 run_ld_link_tests $armelftests_common
diff --git a/ld/testsuite/ld-arm/ifunc-gdesc.r b/ld/testsuite/ld-arm/ifunc-gdesc.r
new file mode 100644
index 0000000..a49dd2b
--- /dev/null
+++ b/ld/testsuite/ld-arm/ifunc-gdesc.r
@@ -0,0 +1,6 @@
+tmpdir/ifunc-gdesc.so:     file format elf32-(big|little)arm
+DYNAMIC RELOCATION RECORDS
+OFFSET   TYPE              VALUE 
+0000825c R_ARM_IRELATIVE   \*ABS\*
+00008248 R_ARM_TLS_DESC    \*ABS\*
+00008250 R_ARM_TLS_DESC    \*ABS\*
diff --git a/ld/testsuite/ld-arm/ifunc-gdesc.s b/ld/testsuite/ld-arm/ifunc-gdesc.s
new file mode 100644
index 0000000..a07a5d5
--- /dev/null
+++ b/ld/testsuite/ld-arm/ifunc-gdesc.s
@@ -0,0 +1,29 @@
+
+	.arm
+
+foo:
+	bl	ifunc1(PLT)
+	ldr	r0,1f
+2:	bl	loc1(tlscall)
+	nop
+1:	.word	loc1(tlsdesc) + (. - 2b)
+
+	ldr	r0,1f
+2:	bl	loc2(tlscall)
+	nop
+1:	.word	loc2(tlsdesc) + (. - 2b)
+
+	.type	ifunc1,%gnu_indirect_function
+	.global ifunc1
+ifunc1:
+	mov	pc,lr
+	.size	ifunc1,.-ifunc1
+
+
+	.section	.tdata,"awT",%progbits
+	.space	8
+	.type	loc1, %object
+loc1:	.space	4
+	.type	loc2, %object
+loc2:	.space	4
+
diff --git a/ld/testsuite/ld-arm/ifunc-gdesc.ver b/ld/testsuite/ld-arm/ifunc-gdesc.ver
new file mode 100644
index 0000000..a82ffc4
--- /dev/null
+++ b/ld/testsuite/ld-arm/ifunc-gdesc.ver
@@ -0,0 +1,4 @@
+{
+global: foo;
+local: *;
+};
\ No newline at end of file
-- 
1.9.0