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Don't create copy relocs or dummy plt's if given -z notext. 

Being passed -z notext is a pretty strong indication that the user is
OK with text relocations. This is not the same behavior as bfd, but
bfd defaults to -z notext, so it has to try to avoid text relocations
and use them as a last resort.

llvm-svn: 297789
This commit is contained in:
Rafael Espindola 2017-03-14 22:50:07 +00:00
parent a9bd572b6f
commit d3c22f08b3
3 changed files with 39 additions and 7 deletions
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13
lld/ELF/Relocations.cpp
View File

@ -520,12 +520,11 @@ static RelExpr adjustExpr(const elf::ObjectFile<ELFT> &File, SymbolBody &Body,
// only memory. We can hack around it if we are producing an executable and // only memory. We can hack around it if we are producing an executable and
// the refered symbol can be preemepted to refer to the executable. // the refered symbol can be preemepted to refer to the executable.
if (Config->Shared || (Config->pic() && !isRelExpr(Expr))) { if (Config->Shared || (Config->pic() && !isRelExpr(Expr))) {
if (Config->ZText) error(S.getLocation<ELFT>(RelOff) + ": can't create dynamic relocation " +
error(S.getLocation<ELFT>(RelOff) + ": can't create dynamic relocation " + toString(Type) + " against " +
toString(Type) + " against " + (Body.getName().empty() ? "local symbol in readonly segment"
(Body.getName().empty() ? "local symbol in readonly segment" : "symbol '" + toString(Body) + "'") +
: "symbol '" + toString(Body) + "'") + " defined in " + toString(Body.File));
" defined in " + toString(Body.File));
return Expr; return Expr;
} }
if (Body.getVisibility() != STV_DEFAULT) { if (Body.getVisibility() != STV_DEFAULT) {
@ -655,6 +654,8 @@ static void scanRelocs(InputSectionBase &C, ArrayRef<RelTy> Rels) {
typedef typename ELFT::uint uintX_t; typedef typename ELFT::uint uintX_t;
bool IsWrite = C.Flags & SHF_WRITE; bool IsWrite = C.Flags & SHF_WRITE;
if (!Config->ZText)
IsWrite = true;
auto AddDyn = [=](const DynamicReloc<ELFT> &Reloc) { auto AddDyn = [=](const DynamicReloc<ELFT> &Reloc) {
In<ELFT>::RelaDyn->addReloc(Reloc); In<ELFT>::RelaDyn->addReloc(Reloc);

10
lld/test/ELF/Inputs/ztext-text-notext.s Normal file
View File

@ -0,0 +1,10 @@
.global bar
.type bar, @object
.size bar, 8
bar:
.quad 0
.global zed
.type zed, @function
zed:
nop

23
lld/test/ELF/ztext-text-notext.s
View File

@ -1,15 +1,36 @@
# REQUIRES: x86 # REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o # RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
# RUN: ld.lld -z notext %t.o -o %t -shared # RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %p/Inputs/ztext-text-notext.s -o %t2.o
# RUN: ld.lld %t2.o -o %t2.so -shared
# RUN: ld.lld -z notext %t.o %t2.so -o %t -shared
# RUN: llvm-readobj -dynamic-table -r %t | FileCheck %s # RUN: llvm-readobj -dynamic-table -r %t | FileCheck %s
# RUN: ld.lld -z notext %t.o %t2.so -o %t2 -pie
# RUN: llvm-readobj -dynamic-table -r %t2 | FileCheck %s
# RUN: ld.lld -z notext %t.o %t2.so -o %t3
# RUN: llvm-readobj -dynamic-table -r %t3 | FileCheck --check-prefix=STATIC %s
# If the preference is to have text relocations, don't create plt of copy relocations.
# CHECK: Relocations [ # CHECK: Relocations [
# CHECK-NEXT: Section {{.*}} .rela.dyn { # CHECK-NEXT: Section {{.*}} .rela.dyn {
# CHECK-NEXT: 0x1000 R_X86_64_RELATIVE - 0x1000 # CHECK-NEXT: 0x1000 R_X86_64_RELATIVE - 0x1000
# CHECK-NEXT: 0x1008 R_X86_64_64 bar 0x0
# CHECK-NEXT: 0x1010 R_X86_64_PC64 zed 0x0
# CHECK-NEXT: } # CHECK-NEXT: }
# CHECK-NEXT: ] # CHECK-NEXT: ]
# CHECK: DynamicSection [ # CHECK: DynamicSection [
# CHECK: 0x0000000000000016 TEXTREL 0x0 # CHECK: 0x0000000000000016 TEXTREL 0x0
# STATIC: Relocations [
# STATIC-NEXT: Section {{.*}} .rela.dyn {
# STATIC-NEXT: 0x201008 R_X86_64_64 bar 0x0
# STATIC-NEXT: 0x201010 R_X86_64_PC64 zed 0x0
# STATIC-NEXT: }
# STATIC-NEXT: ]
# STATIC: DynamicSection [
# STATIC: 0x0000000000000016 TEXTREL 0x0
foo: foo:
.quad foo .quad foo
.quad bar
.quad zed - .