[binutils-gdb/binutils-2_31-branch] PR23937, powerpc64le local ifunc IRELATIVE relocs are wrong

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=0f494b01431de53959dd72ccfed06a01d5172e3f

commit 0f494b01431de53959dd72ccfed06a01d5172e3f
Author: Alan Modra <amodra@gmail.com>
Date:   Fri Nov 30 15:34:11 2018 +1030

    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)

Diff:
---
 bfd/ChangeLog                       |  6 ++++
 bfd/elf64-ppc.c                     |  3 +-
 ld/ChangeLog                        |  6 ++++
 ld/testsuite/ld-powerpc/powerpc.exp |  1 +
 ld/testsuite/ld-powerpc/pr23937.d   | 10 ++++++
 ld/testsuite/ld-powerpc/pr23937.s   | 65 +++++++++++++++++++++++++++++++++++++
 6 files changed, 90 insertions(+), 1 deletion(-)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 2cdb834..fa4173d 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 139ed1a..746506e 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 8806a7d..38963b9 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 de76296..5ec3850 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 0000000..6ef79e8
--- /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 0000000..155e53a
--- /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"