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-rw-r--r--lld/ELF/Writer.cpp94
1 files changed, 37 insertions, 57 deletions
diff --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp
index dc0f9254596a..6373044d8804 100644
--- a/lld/ELF/Writer.cpp
+++ b/lld/ELF/Writer.cpp
@@ -135,7 +135,7 @@ StringRef getOutputSectionName(const InputSectionBase *s) {
}
static bool needsInterpSection() {
- return !sharedFiles.empty() && !config->dynamicLinker.empty() &&
+ return !config->shared && !config->dynamicLinker.empty() &&
script->needsInterpSection();
}
@@ -283,7 +283,7 @@ void addReservedSymbols() {
// different in different DSOs, so we chose the start address of the DSO.
addOptionalRegular("__dso_handle", Out::elfHeader, 0, STV_HIDDEN);
- // If linker script do layout we do not need to create any standart symbols.
+ // If linker script do layout we do not need to create any standard symbols.
if (script->hasSectionsCommand)
return;
@@ -515,9 +515,15 @@ template <class ELFT> void createSyntheticSections() {
/*sort=*/false);
add(in.relaIplt);
- in.plt = make<PltSection>(false);
+ if ((config->emachine == EM_386 || config->emachine == EM_X86_64) &&
+ (config->andFeatures & GNU_PROPERTY_X86_FEATURE_1_IBT)) {
+ in.ibtPlt = make<IBTPltSection>();
+ add(in.ibtPlt);
+ }
+
+ in.plt = make<PltSection>();
add(in.plt);
- in.iplt = make<PltSection>(true);
+ in.iplt = make<IpltSection>();
add(in.iplt);
if (config->andFeatures)
@@ -1238,10 +1244,9 @@ static DenseMap<const InputSectionBase *, int> buildSectionOrder() {
// We want both global and local symbols. We get the global ones from the
// symbol table and iterate the object files for the local ones.
- symtab->forEachSymbol([&](Symbol *sym) {
+ for (Symbol *sym : symtab->symbols())
if (!sym->isLazy())
addSym(*sym);
- });
for (InputFile *file : objectFiles)
for (Symbol *sym : file->getSymbols())
@@ -1637,37 +1642,6 @@ static void removeUnusedSyntheticSections() {
}
}
-// Returns true if a symbol can be replaced at load-time by a symbol
-// with the same name defined in other ELF executable or DSO.
-static bool computeIsPreemptible(const Symbol &b) {
- assert(!b.isLocal());
-
- // Only symbols that appear in dynsym can be preempted.
- if (!b.includeInDynsym())
- return false;
-
- // Only default visibility symbols can be preempted.
- if (b.visibility != STV_DEFAULT)
- return false;
-
- // At this point copy relocations have not been created yet, so any
- // symbol that is not defined locally is preemptible.
- if (!b.isDefined())
- return true;
-
- if (!config->shared)
- return false;
-
- // If the dynamic list is present, it specifies preemptable symbols in a DSO.
- if (config->hasDynamicList)
- return b.inDynamicList;
-
- // -Bsymbolic means that definitions are not preempted.
- if (config->bsymbolic || (config->bsymbolicFunctions && b.isFunc()))
- return false;
- return true;
-}
-
// Create output section objects and add them to OutputSections.
template <class ELFT> void Writer<ELFT>::finalizeSections() {
Out::preinitArray = findSection(".preinit_array");
@@ -1734,8 +1708,8 @@ template <class ELFT> void Writer<ELFT>::finalizeSections() {
for (Partition &part : partitions)
finalizeSynthetic(part.ehFrame);
- symtab->forEachSymbol(
- [](Symbol *s) { s->isPreemptible = computeIsPreemptible(*s); });
+ for (Symbol *sym : symtab->symbols())
+ sym->isPreemptible = computeIsPreemptible(*sym);
// Change values of linker-script-defined symbols from placeholders (assigned
// by declareSymbols) to actual definitions.
@@ -1757,7 +1731,7 @@ template <class ELFT> void Writer<ELFT>::finalizeSections() {
if (!config->allowShlibUndefined) {
// Error on undefined symbols in a shared object, if all of its DT_NEEDED
- // entires are seen. These cases would otherwise lead to runtime errors
+ // entries are seen. These cases would otherwise lead to runtime errors
// reported by the dynamic linker.
//
// ld.bfd traces all DT_NEEDED to emulate the logic of the dynamic linker to
@@ -1769,19 +1743,18 @@ template <class ELFT> void Writer<ELFT>::finalizeSections() {
return symtab->soNames.count(needed);
});
- symtab->forEachSymbol([](Symbol *sym) {
+ for (Symbol *sym : symtab->symbols())
if (sym->isUndefined() && !sym->isWeak())
if (auto *f = dyn_cast_or_null<SharedFile>(sym->file))
if (f->allNeededIsKnown)
error(toString(f) + ": undefined reference to " + toString(*sym));
- });
}
// Now that we have defined all possible global symbols including linker-
// synthesized ones. Visit all symbols to give the finishing touches.
- symtab->forEachSymbol([](Symbol *sym) {
+ for (Symbol *sym : symtab->symbols()) {
if (!includeInSymtab(*sym))
- return;
+ continue;
if (in.symTab)
in.symTab->addSymbol(sym);
@@ -1791,7 +1764,7 @@ template <class ELFT> void Writer<ELFT>::finalizeSections() {
if (file->isNeeded && !sym->isUndefined())
addVerneed(sym);
}
- });
+ }
// We also need to scan the dynamic relocation tables of the other partitions
// and add any referenced symbols to the partition's dynsym.
@@ -1979,7 +1952,7 @@ template <class ELFT> void Writer<ELFT>::addStartEndSymbols() {
// program text is above 2 GiB. We use the address of the .text
// section instead to prevent that failure.
//
- // In a rare sitaution, .text section may not exist. If that's the
+ // In rare situations, the .text section may not exist. If that's the
// case, use the image base address as a last resort.
OutputSection *Default = findSection(".text");
if (!Default)
@@ -2085,7 +2058,7 @@ std::vector<PhdrEntry *> Writer<ELFT>::createPhdrs(Partition &part) {
}
// PT_GNU_RELRO includes all sections that should be marked as
- // read-only by dynamic linker after proccessing relocations.
+ // read-only by dynamic linker after processing relocations.
// Current dynamic loaders only support one PT_GNU_RELRO PHDR, give
// an error message if more than one PT_GNU_RELRO PHDR is required.
PhdrEntry *relRo = make<PhdrEntry>(PT_GNU_RELRO, PF_R);
@@ -2172,14 +2145,16 @@ std::vector<PhdrEntry *> Writer<ELFT>::createPhdrs(Partition &part) {
if (OutputSection *cmd = findSection(".openbsd.randomdata", partNo))
addHdr(PT_OPENBSD_RANDOMIZE, cmd->getPhdrFlags())->add(cmd);
- // PT_GNU_STACK is a special section to tell the loader to make the
- // pages for the stack non-executable. If you really want an executable
- // stack, you can pass -z execstack, but that's not recommended for
- // security reasons.
- unsigned perm = PF_R | PF_W;
- if (config->zExecstack)
- perm |= PF_X;
- addHdr(PT_GNU_STACK, perm)->p_memsz = config->zStackSize;
+ if (config->zGnustack != GnuStackKind::None) {
+ // PT_GNU_STACK is a special section to tell the loader to make the
+ // pages for the stack non-executable. If you really want an executable
+ // stack, you can pass -z execstack, but that's not recommended for
+ // security reasons.
+ unsigned perm = PF_R | PF_W;
+ if (config->zGnustack == GnuStackKind::Exec)
+ perm |= PF_X;
+ addHdr(PT_GNU_STACK, perm)->p_memsz = config->zStackSize;
+ }
// PT_OPENBSD_WXNEEDED is a OpenBSD-specific header to mark the executable
// is expected to perform W^X violations, such as calling mprotect(2) or
@@ -2188,6 +2163,9 @@ std::vector<PhdrEntry *> Writer<ELFT>::createPhdrs(Partition &part) {
if (config->zWxneeded)
addHdr(PT_OPENBSD_WXNEEDED, PF_X);
+ if (OutputSection *cmd = findSection(".note.gnu.property", partNo))
+ addHdr(PT_GNU_PROPERTY, PF_R)->add(cmd);
+
// Create one PT_NOTE per a group of contiguous SHT_NOTE sections with the
// same alignment.
PhdrEntry *note = nullptr;
@@ -2423,7 +2401,7 @@ struct SectionOffset {
} // namespace
// Check whether sections overlap for a specific address range (file offsets,
-// load and virtual adresses).
+// load and virtual addresses).
static void checkOverlap(StringRef name, std::vector<SectionOffset> &sections,
bool isVirtualAddr) {
llvm::sort(sections, [=](const SectionOffset &a, const SectionOffset &b) {
@@ -2593,7 +2571,9 @@ template <class ELFT> void Writer<ELFT>::openFile() {
unlinkAsync(config->outputFile);
unsigned flags = 0;
if (!config->relocatable)
- flags = FileOutputBuffer::F_executable;
+ flags |= FileOutputBuffer::F_executable;
+ if (!config->mmapOutputFile)
+ flags |= FileOutputBuffer::F_no_mmap;
Expected<std::unique_ptr<FileOutputBuffer>> bufferOrErr =
FileOutputBuffer::create(config->outputFile, fileSize, flags);
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-08 06:09:02 +0000