ELF: Don't reuse a thunk in a different loadable partition.
There's no guarantee that the other partition will be loaded, so it
can't be reused.
Differential Revision: https://reviews.llvm.org/D62365
git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@361926 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/ELF/Relocations.cpp b/ELF/Relocations.cpp
index aab5385..b02e1cc 100644
--- a/ELF/Relocations.cpp
+++ b/ELF/Relocations.cpp
@@ -1607,12 +1607,22 @@
InputSectionDescription *ISD,
uint64_t Off) {
auto *TS = make<ThunkSection>(OS, Off);
+ TS->Partition = OS->Partition;
ISD->ThunkSections.push_back({TS, Pass});
return TS;
}
-std::pair<Thunk *, bool> ThunkCreator::getThunk(Symbol &Sym, RelType Type,
- uint64_t Src) {
+static bool isThunkSectionCompatible(InputSection *Source,
+ SectionBase *Target) {
+ // We can't reuse thunks in different loadable partitions because they might
+ // not be loaded. But partition 1 (the main partition) will always be loaded.
+ if (Source->Partition != Target->Partition)
+ return Target->Partition == 1;
+ return true;
+}
+
+std::pair<Thunk *, bool> ThunkCreator::getThunk(InputSection *IS, Symbol &Sym,
+ RelType Type, uint64_t Src) {
std::vector<Thunk *> *ThunkVec = nullptr;
// We use (section, offset) pair to find the thunk position if possible so
@@ -1625,7 +1635,8 @@
// Check existing Thunks for Sym to see if they can be reused
for (Thunk *T : *ThunkVec)
- if (T->isCompatibleWith(Type) &&
+ if (isThunkSectionCompatible(IS, T->getThunkTargetSym()->Section) &&
+ T->isCompatibleWith(Type) &&
Target->inBranchRange(Type, Src, T->getThunkTargetSym()->getVA()))
return std::make_pair(T, false);
@@ -1709,7 +1720,7 @@
Thunk *T;
bool IsNew;
- std::tie(T, IsNew) = getThunk(*Rel.Sym, Rel.Type, Src);
+ std::tie(T, IsNew) = getThunk(IS, *Rel.Sym, Rel.Type, Src);
if (IsNew) {
// Find or create a ThunkSection for the new Thunk
diff --git a/ELF/Relocations.h b/ELF/Relocations.h
index 923aa46..00156f5 100644
--- a/ELF/Relocations.h
+++ b/ELF/Relocations.h
@@ -136,7 +136,8 @@
void createInitialThunkSections(ArrayRef<OutputSection *> OutputSections);
- std::pair<Thunk *, bool> getThunk(Symbol &Sym, RelType Type, uint64_t Src);
+ std::pair<Thunk *, bool> getThunk(InputSection *IS, Symbol &Sym, RelType Type,
+ uint64_t Src);
ThunkSection *addThunkSection(OutputSection *OS, InputSectionDescription *,
uint64_t Off);
diff --git a/test/ELF/partition-thunk-reuse.s b/test/ELF/partition-thunk-reuse.s
new file mode 100644
index 0000000..6425bdf
--- /dev/null
+++ b/test/ELF/partition-thunk-reuse.s
@@ -0,0 +1,45 @@
+// REQUIRES: arm
+// RUN: llvm-mc %s -o %t.o -filetype=obj --triple=armv7-unknown-linux -arm-add-build-attributes
+// RUN: ld.lld %t.o -o %t --export-dynamic --gc-sections
+// RUN: llvm-nm %t | FileCheck %s
+
+// CHECK: __Thumbv7ABSLongThunk__start
+// CHECK: __Thumbv7ABSLongThunk__start
+
+// CHECK: __Thumbv7ABSLongThunk_foo
+// CHECK-NOT: __Thumbv7ABSLongThunk_foo
+
+.thumb
+
+.section .llvm_sympart.g1,"",%llvm_sympart
+.asciz "part1"
+.4byte f1
+
+.section .llvm_sympart.g2,"",%llvm_sympart
+.asciz "part2"
+.4byte f2
+
+.section .text._start,"ax",%progbits
+.globl _start
+_start:
+bx lr
+foo:
+b f0
+.zero 17*1048576
+
+.section .text.f0,"ax",%progbits
+.globl f0
+f0:
+b foo
+
+.section .text.f1,"aw",%progbits
+.globl f1
+f1:
+b _start
+b foo
+
+.section .text.f2,"ax",%progbits
+.globl f2
+f2:
+b _start
+b foo