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[ELF] - Implemented support for R_386_PC8/R_386_8 relocations. 

These relocations are used in linux kernel.

Differential revision: https://reviews.llvm.org/D28094

llvm-svn: 293054
This commit is contained in:
George Rimar 2017-01-25 13:36:49 +00:00
parent a56833b0e7
commit f242ffa095
4 changed files with 26 additions and 16 deletions
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13
lld/ELF/Target.cpp
View File

@ -358,6 +358,7 @@ X86TargetInfo::X86TargetInfo() {
RelExpr X86TargetInfo::getRelExpr(uint32_t Type, const SymbolBody &S) const {
switch (Type) {
case R_386_8:
case R_386_16:
case R_386_32:
case R_386_TLS_LDO_32:
@ -368,6 +369,7 @@ RelExpr X86TargetInfo::getRelExpr(uint32_t Type, const SymbolBody &S) const {
return R_TLSLD;
case R_386_PLT32:
return R_PLT_PC;
case R_386_PC8:
case R_386_PC16:
case R_386_PC32:
return R_PC;
@ -488,6 +490,9 @@ uint64_t X86TargetInfo::getImplicitAddend(const uint8_t *Buf,
switch (Type) {
default:
return 0;
case R_386_8:
case R_386_PC8:
return *Buf;
case R_386_16:
case R_386_PC16:
return read16le(Buf);
@ -507,8 +512,12 @@ void X86TargetInfo::relocateOne(uint8_t *Loc, uint32_t Type,
uint64_t Val) const {
checkInt<32>(Loc, Val, Type);
// R_386_PC16 and R_386_16 are not part of the current i386 psABI. They are
// used by 16-bit x86 objects, like boot loaders.
// R_386_PC16/R_386_16/R_386_PC8/R_386_8 are not part of the current i386
// psABI. They are used by 16-bit x86 objects, like boot loaders.
if (Type == R_386_8 || Type == R_386_PC8) {
*Loc = (uint8_t)Val;
return;
}
if (Type == R_386_16 || Type == R_386_PC16) {
write16le(Loc, Val);
return;

2
lld/test/ELF/Inputs/i386-pc8.s Normal file
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@ -0,0 +1,2 @@
.global und
und:

13
lld/test/ELF/i386-pc8.s Normal file
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@ -0,0 +1,13 @@
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=i386-pc-linux-gnu %s -o %t1.o
# RUN: llvm-mc -filetype=obj -triple=i386-pc-linux-gnu %S/Inputs/i386-pc8.s -o %t2.o
# RUN: ld.lld %t1.o %t2.o -o %t.out
# RUN: llvm-objdump -s -section=.text %t.out | FileCheck %s
# CHECK: Contents of section .text:
# CHECK-NEXT: 11000 15253748
.byte und-.+0x11
.byte und-.+0x22
.byte und+0x33
.byte und+0x44

14
lld/test/ELF/unknown-reloc.s
View File

@ -1,14 +0,0 @@
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=i386-pc-linux-gnu %s -o %t1.o
# RUN: llvm-mc -filetype=obj -triple=i386-pc-linux-gnu %S/Inputs/unknown-reloc.s -o %t2.o
# RUN: not ld.lld %t1.o %t2.o -o %t.out 2>&1 | FileCheck %s
# CHECK: do not know how to handle relocation 'R_386_PC8' (23)
# CHECK: do not know how to handle relocation 'R_386_8' (22)
.text
.global foo
foo:
.byte und-foo
.byte foo