Discussion:
PR23937, powerpc64le local ifunc IRELATIVE relocs are wrong
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Alan Modra
2018-11-30 05:56:42 UTC
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IFUNC resolvers must always be called via their global entry point.
They will be called from ld.so rather than from the local executable.

Applied master and binutils-2.31 branch.

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.

diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 7c3534ac65..a2d3ea067c 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -12882,7 +12882,8 @@ 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/testsuite/ld-powerpc/powerpc.exp b/ld/testsuite/ld-powerpc/powerpc.exp
index 12590f1817..826dfedc12 100644
--- a/ld/testsuite/ld-powerpc/powerpc.exp
+++ b/ld/testsuite/ld-powerpc/powerpc.exp
@@ -334,6 +334,7 @@ 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 0000000000..6ef79e81cf
--- /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 0000000000..155e53adb7
--- /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.-***@ha
+ addi 2,2,.TOC.-***@l
+ .localentry implementation,.-implementation
+ mflr 0
+ addis 3,2,***@toc@ha
+ addi 3,3,***@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.-***@ha
+ addi 2,2,.TOC.-***@l
+ .localentry resolver,.-resolver
+ addis 3,2,***@toc@ha
+ addi 3,3,***@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.-***@ha
+ addi 2,2,.TOC.-***@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"
--
Alan Modra
Australia Development Lab, IBM
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