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-rw-r--r--ELF/Relocations.cpp160
1 files changed, 99 insertions, 61 deletions
diff --git a/ELF/Relocations.cpp b/ELF/Relocations.cpp
index 54cc6dd89d46..98c1349a2f0d 100644
--- a/ELF/Relocations.cpp
+++ b/ELF/Relocations.cpp
@@ -43,6 +43,7 @@
#include "Relocations.h"
#include "Config.h"
+#include "LinkerScript.h"
#include "Memory.h"
#include "OutputSections.h"
#include "Strings.h"
@@ -967,48 +968,51 @@ template <class ELFT> void elf::scanRelocations(InputSectionBase &S) {
// in the Sections vector, and recalculate the InputSection output section
// offsets.
// This may invalidate any output section offsets stored outside of InputSection
-void ThunkCreator::mergeThunks(OutputSection *OS,
- std::vector<ThunkSection *> &Thunks) {
- // Order Thunks in ascending OutSecOff
- auto ThunkCmp = [](const ThunkSection *A, const ThunkSection *B) {
- return A->OutSecOff < B->OutSecOff;
- };
- std::stable_sort(Thunks.begin(), Thunks.end(), ThunkCmp);
-
- // Merge sorted vectors of Thunks and InputSections by OutSecOff
- std::vector<InputSection *> Tmp;
- Tmp.reserve(OS->Sections.size() + Thunks.size());
- auto MergeCmp = [](const InputSection *A, const InputSection *B) {
- // std::merge requires a strict weak ordering.
- if (A->OutSecOff < B->OutSecOff)
- return true;
- if (A->OutSecOff == B->OutSecOff)
- // Check if Thunk is immediately before any specific Target InputSection
- // for example Mips LA25 Thunks.
- if (auto *TA = dyn_cast<ThunkSection>(A))
- if (TA && TA->getTargetInputSection() == B)
- return true;
- return false;
- };
- std::merge(OS->Sections.begin(), OS->Sections.end(), Thunks.begin(),
- Thunks.end(), std::back_inserter(Tmp), MergeCmp);
- OS->Sections = std::move(Tmp);
- OS->assignOffsets();
+void ThunkCreator::mergeThunks() {
+ for (auto &KV : ThunkSections) {
+ std::vector<InputSection *> *ISR = KV.first;
+ std::vector<ThunkSection *> &Thunks = KV.second;
+
+ // Order Thunks in ascending OutSecOff
+ auto ThunkCmp = [](const ThunkSection *A, const ThunkSection *B) {
+ return A->OutSecOff < B->OutSecOff;
+ };
+ std::stable_sort(Thunks.begin(), Thunks.end(), ThunkCmp);
+
+ // Merge sorted vectors of Thunks and InputSections by OutSecOff
+ std::vector<InputSection *> Tmp;
+ Tmp.reserve(ISR->size() + Thunks.size());
+ auto MergeCmp = [](const InputSection *A, const InputSection *B) {
+ // std::merge requires a strict weak ordering.
+ if (A->OutSecOff < B->OutSecOff)
+ return true;
+ if (A->OutSecOff == B->OutSecOff)
+ // Check if Thunk is immediately before any specific Target InputSection
+ // for example Mips LA25 Thunks.
+ if (auto *TA = dyn_cast<ThunkSection>(A))
+ if (TA && TA->getTargetInputSection() == B)
+ return true;
+ return false;
+ };
+ std::merge(ISR->begin(), ISR->end(), Thunks.begin(), Thunks.end(),
+ std::back_inserter(Tmp), MergeCmp);
+ *ISR = std::move(Tmp);
+ }
}
-ThunkSection *ThunkCreator::getOSThunkSec(ThunkSection *&TS,
- OutputSection *OS) {
- if (TS == nullptr) {
+ThunkSection *ThunkCreator::getOSThunkSec(OutputSection *OS,
+ std::vector<InputSection *> *ISR) {
+ if (CurTS == nullptr) {
uint32_t Off = 0;
for (auto *IS : OS->Sections) {
Off = IS->OutSecOff + IS->getSize();
if ((IS->Flags & SHF_EXECINSTR) == 0)
break;
}
- TS = make<ThunkSection>(OS, Off);
- ThunkSections[OS].push_back(TS);
+ CurTS = make<ThunkSection>(OS, Off);
+ ThunkSections[ISR].push_back(CurTS);
}
- return TS;
+ return CurTS;
}
ThunkSection *ThunkCreator::getISThunkSec(InputSection *IS, OutputSection *OS) {
@@ -1017,7 +1021,21 @@ ThunkSection *ThunkCreator::getISThunkSec(InputSection *IS, OutputSection *OS) {
return TS;
auto *TOS = IS->getParent();
TS = make<ThunkSection>(TOS, IS->OutSecOff);
- ThunkSections[TOS].push_back(TS);
+
+ // Find InputSectionRange within TOS that IS is in
+ OutputSectionCommand *C = Script->getCmd(TOS);
+ std::vector<InputSection *> *Range = nullptr;
+ for (BaseCommand *BC : C->Commands)
+ if (auto *ISD = dyn_cast<InputSectionDescription> (BC)) {
+ InputSection *first = ISD->Sections.front();
+ InputSection *last = ISD->Sections.back();
+ if (IS->OutSecOff >= first->OutSecOff &&
+ IS->OutSecOff <= last->OutSecOff) {
+ Range = &ISD->Sections;
+ break;
+ }
+ }
+ ThunkSections[Range].push_back(TS);
ThunkedSections[IS] = TS;
return TS;
}
@@ -1030,6 +1048,27 @@ std::pair<Thunk *, bool> ThunkCreator::getThunk(SymbolBody &Body,
return std::make_pair(res.first->second, res.second);
}
+// Call Fn on every executable InputSection accessed via the linker script
+// InputSectionDescription::Sections.
+void ThunkCreator::forEachExecInputSection(
+ ArrayRef<OutputSectionCommand *> OutputSections,
+ std::function<void(OutputSection *, std::vector<InputSection *> *,
+ InputSection *)>
+ Fn) {
+ for (OutputSectionCommand *Cmd : OutputSections) {
+ OutputSection *OS = Cmd->Sec;
+ if (!(OS->Flags & SHF_ALLOC) || !(OS->Flags & SHF_EXECINSTR))
+ continue;
+ if (OutputSectionCommand *C = Script->getCmd(OS))
+ for (BaseCommand *BC : C->Commands)
+ if (auto *ISD = dyn_cast<InputSectionDescription>(BC)) {
+ CurTS = nullptr;
+ for (InputSection* IS : ISD->Sections)
+ Fn(OS, &ISD->Sections, IS);
+ }
+ }
+}
+
// Process all relocations from the InputSections that have been assigned
// to OutputSections and redirect through Thunks if needed.
//
@@ -1040,42 +1079,41 @@ std::pair<Thunk *, bool> ThunkCreator::getThunk(SymbolBody &Body,
//
// FIXME: All Thunks are assumed to be in range of the relocation. Range
// extension Thunks are not yet supported.
-bool ThunkCreator::createThunks(ArrayRef<OutputSection *> OutputSections) {
+bool ThunkCreator::createThunks(
+ ArrayRef<OutputSectionCommand *> OutputSections) {
// Create all the Thunks and insert them into synthetic ThunkSections. The
// ThunkSections are later inserted back into the OutputSection.
// We separate the creation of ThunkSections from the insertion of the
// ThunkSections back into the OutputSection as ThunkSections are not always
// inserted into the same OutputSection as the caller.
- for (OutputSection *OS : OutputSections) {
- ThunkSection *OSTS = nullptr;
- for (InputSection *IS : OS->Sections) {
- for (Relocation &Rel : IS->Relocations) {
- SymbolBody &Body = *Rel.Sym;
- if (!Target->needsThunk(Rel.Expr, Rel.Type, IS->File, Body))
- continue;
- Thunk *T;
- bool IsNew;
- std::tie(T, IsNew) = getThunk(Body, Rel.Type);
- if (IsNew) {
- // Find or create a ThunkSection for the new Thunk
- ThunkSection *TS;
- if (auto *TIS = T->getTargetInputSection())
- TS = getISThunkSec(TIS, OS);
- else
- TS = getOSThunkSec(OSTS, OS);
- TS->addThunk(T);
+ forEachExecInputSection(
+ OutputSections, [=](OutputSection *OS, std::vector<InputSection*> *ISR,
+ InputSection *IS) {
+ for (Relocation &Rel : IS->Relocations) {
+ SymbolBody &Body = *Rel.Sym;
+ if (!Target->needsThunk(Rel.Expr, Rel.Type, IS->File, Body))
+ continue;
+ Thunk *T;
+ bool IsNew;
+ std::tie(T, IsNew) = getThunk(Body, Rel.Type);
+ if (IsNew) {
+ // Find or create a ThunkSection for the new Thunk
+ ThunkSection *TS;
+ if (auto *TIS = T->getTargetInputSection())
+ TS = getISThunkSec(TIS, OS);
+ else
+ TS = getOSThunkSec(OS, ISR);
+ TS->addThunk(T);
+ }
+ // Redirect relocation to Thunk, we never go via the PLT to a Thunk
+ Rel.Sym = T->ThunkSym;
+ Rel.Expr = fromPlt(Rel.Expr);
}
- // Redirect relocation to Thunk, we never go via the PLT to a Thunk
- Rel.Sym = T->ThunkSym;
- Rel.Expr = fromPlt(Rel.Expr);
- }
- }
- }
+ });
// Merge all created synthetic ThunkSections back into OutputSection
- for (auto &KV : ThunkSections)
- mergeThunks(KV.first, KV.second);
+ mergeThunks();
return !ThunkSections.empty();
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-04 10:44:45 +0000