PR23937, powerpc64le local ifunc IRELATIVE relocs are wrong

IFUNC resolvers must always be called via their global entry point.
They will be called from ld.so rather than from the local executable.

	PR 23937
bfd/
	* elf64-ppc.c (write_plt_relocs_for_local_syms): Don't add local
	entry offset for ifuncs.
ld/
	* testsuite/ld-powerpc/pr23937.d,
	* testsuite/ld-powerpc/pr23937.s: New test.
	* testsuite/ld-powerpc/powerpc.exp: Run it.

(cherry picked from commit ba85c15dabe144e4bcee5a1b388b32bee10729e1)
(cherry picked from commit 0f494b01431de53959dd72ccfed06a01d5172e3f)
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>

6 files changed, 90 insertions, 1 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 2cdb83480eb..fa4173da3aa 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2018-11-30  Alan Modra  <amodra@gmail.com>
+
+	PR 23937
+	* elf64-ppc.c (write_plt_relocs_for_local_syms): Don't add local
+	entry offset for ifuncs.
+
 2018-11-27  Tamar Christina  <tamar.christina@arm.com>
 
 	Backport from mainline
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 139ed1abcda..746506ef09e 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -13530,7 +13530,8 @@ write_plt_relocs_for_local_syms (struct bfd_link_info *info)
 		}
 
 	      val = sym->st_value + ent->addend;
-	      val += PPC64_LOCAL_ENTRY_OFFSET (sym->st_other);
+	      if (ELF_ST_TYPE (sym->st_info) != STT_GNU_IFUNC)
+		val += PPC64_LOCAL_ENTRY_OFFSET (sym->st_other);
 	      if (sym_sec != NULL && sym_sec->output_section != NULL)
 		val += sym_sec->output_offset + sym_sec->output_section->vma;
 
diff --git a/ld/ChangeLog b/ld/ChangeLog
index 8806a7db98f..38963b90cf8 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,9 @@
+2018-11-30  Alan Modra  <amodra@gmail.com>
+
+	* testsuite/ld-powerpc/pr23937.d,
+	* testsuite/ld-powerpc/pr23937.s: New test.
+	* testsuite/ld-powerpc/powerpc.exp: Run it.
+
 2018-11-27  Tamar Christina  <tamar.christina@arm.com>
 
 	PR ld/23904
diff --git a/ld/testsuite/ld-powerpc/powerpc.exp b/ld/testsuite/ld-powerpc/powerpc.exp
index de762966e5d..5ec3850787e 100644
--- a/ld/testsuite/ld-powerpc/powerpc.exp
+++ b/ld/testsuite/ld-powerpc/powerpc.exp
@@ -328,6 +328,7 @@ if [ supports_ppc64 ] then {
     run_dump_test "dotsym2"
     run_dump_test "dotsym3"
     run_dump_test "dotsym4"
+    run_dump_test "pr23937"
 }
 
 run_dump_test "tlsld32"
diff --git a/ld/testsuite/ld-powerpc/pr23937.d b/ld/testsuite/ld-powerpc/pr23937.d
new file mode 100644
index 00000000000..6ef79e81cf6
--- /dev/null
+++ b/ld/testsuite/ld-powerpc/pr23937.d
@@ -0,0 +1,10 @@
+#as: -a64
+#ld: -melf64ppc --defsym puts=0 --defsym _start=0
+#readelf: -srW
+# Check that the IRELATIVE addend is magic+0, not magic+8
+
+#...
+.* R_PPC64_IRELATIVE +10000180
+#...
+.*: 0+10000180 +20 IFUNC +LOCAL +DEFAULT .* magic
+#pass
diff --git a/ld/testsuite/ld-powerpc/pr23937.s b/ld/testsuite/ld-powerpc/pr23937.s
new file mode 100644
index 00000000000..155e53adb7a
--- /dev/null
+++ b/ld/testsuite/ld-powerpc/pr23937.s
@@ -0,0 +1,65 @@
+	.abiversion 2
+	.text
+	.p2align 4,,15
+	.type	implementation, @function
+implementation:
+.LCF0:
+	addis 2,12,.TOC.-.LCF0@ha
+	addi 2,2,.TOC.-.LCF0@l
+	.localentry	implementation,.-implementation
+	mflr 0
+	addis 3,2,.LC0@toc@ha
+	addi 3,3,.LC0@toc@l
+	std 0,16(1)
+	stdu 1,-32(1)
+	bl puts
+	nop
+	addi 1,1,32
+	li 3,0
+	ld 0,16(1)
+	mtlr 0
+	blr
+	.size	implementation,.-implementation
+
+	.p2align 4,,15
+	.type	resolver, @function
+resolver:
+.LCF1:
+	addis 2,12,.TOC.-.LCF1@ha
+	addi 2,2,.TOC.-.LCF1@l
+	.localentry	resolver,.-resolver
+	addis 3,2,implementation@toc@ha
+	addi 3,3,implementation@toc@l
+	blr
+	.size	resolver,.-resolver
+
+	.type	magic, @gnu_indirect_function
+	.set	magic,resolver
+
+	.section	.text.startup,"ax",@progbits
+	.p2align 4,,15
+	.globl main
+	.type	main, @function
+main:
+.LCF2:
+	addis 2,12,.TOC.-.LCF2@ha
+	addi 2,2,.TOC.-.LCF2@l
+	.localentry	main,.-main
+	mflr 0
+	std 0,16(1)
+	stdu 1,-32(1)
+	bl magic
+	nop
+	addi 1,1,32
+	cntlzw 3,3
+	ld 0,16(1)
+	srwi 3,3,5
+	mtlr 0
+	xori 3,3,0x1
+	blr
+	.size	main,.-main
+
+	.section	.rodata.str1.8,"aMS",@progbits,1
+	.p2align 3
+.LC0:
+	.string	"'ere I am JH"