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Fix crash when processing relocations in .eh_frame. 

This happens when attempting to link shared libraries using exceptions on
MIPS. It requires -z notext because clang generates R_MIPS_64 relocations
inside .eh_frame.
The crash happened because for EhInputSection the OutSec member is null.

Patch by Alexander Richardson!

llvm-svn: 304260
This commit is contained in:
Rafael Espindola 2017-05-31 00:23:23 +00:00
parent 855411566b
commit 180de970c8
2 changed files with 39 additions and 1 deletions
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2
lld/ELF/SyntheticSections.cpp
View File

@ -1185,7 +1185,7 @@ template <class ELFT> void DynamicSection<ELFT>::writeTo(uint8_t *Buf) {
}
uint64_t DynamicReloc::getOffset() const {
return InputSec->OutSec->Addr + InputSec->getOffset(OffsetInSec);
return InputSec->getOutputSection()->Addr + InputSec->getOffset(OffsetInSec);
}
int64_t DynamicReloc::getAddend() const {

38
lld/test/ELF/mips64-eh-abs-reloc.s Normal file
View File

@ -0,0 +1,38 @@
# Having an R_MIPS_64 relocation in eh_frame would previously crash LLD
# REQUIRES: mips
# RUN: llvm-mc -filetype=obj -triple=mips64-unknown-freebsd %s -o %t.o
# RUN: llvm-readobj -r %t.o | FileCheck %s -check-prefix OBJ
# RUN: ld.lld --eh-frame-hdr -shared -z notext -o %t.so %t.o
# RUN: llvm-readobj -r %t.so | FileCheck %s -check-prefix PIC-RELOCS
# Linking this as a PIE executable would also previously crash
# RUN: llvm-mc -filetype=obj -triple=mips64-unknown-freebsd %S/Inputs/archive2.s -o %t-foo.o
# -pie needs -z notext because of the R_MIPS_64 relocation
# RUN: ld.lld --eh-frame-hdr -Bdynamic -pie -z notext -o %t-pie-dynamic.exe %t.o %t-foo.o
# RUN: llvm-readobj -r %t-pie-dynamic.exe | FileCheck %s -check-prefix PIC-RELOCS
# OBJ: Section ({{.*}}) .rela.text {
# OBJ-NEXT: 0x0 R_MIPS_GPREL16/R_MIPS_SUB/R_MIPS_HI16 foo 0x0
# OBJ-NEXT: }
# OBJ-NEXT: Section ({{.*}}) .rela.eh_frame {
# OBJ-NEXT: 0x1C R_MIPS_64/R_MIPS_NONE/R_MIPS_NONE .text 0x0
# OBJ-NEXT: }
# PIC-RELOCS: Relocations [
# PIC-RELOCS-NEXT: Section (7) .rela.dyn {
# PIC-RELOCS-NEXT: {{0x.+}} R_MIPS_REL32/R_MIPS_64/R_MIPS_NONE - 0x10000
# PIC-RELOCS-NEXT: }
# PIC-RELOCS-NEXT:]
.globl foo
bar:
.cfi_startproc
lui $11, %hi(%neg(%gp_rel(foo)))
.cfi_endproc
.globl __start
__start:
b bar