[libomptarget] Support BE ELF files in plugins-nextgen (#85246)
Code in plugins-nextgen reading ELF files is currently hard-coded to
assume a 64-bit little-endian ELF format. Unfortunately, this assumption
is even embedded in the interface between GlobalHandler and Utils/ELF
routines, which use ELF64LE types.
To fix this, I've refactored the interface to use generic types, in
particular by using (a unique_ptr to) ObjectFile instead of
ELF64LEObjectFile, and ELFSymbolRef instead of ELF64LE::Sym.
This allows properly templating over multiple ELF format variants inside
Utils/ELF; specifically, this patch adds support for 64-bit big-endian
ELF files in addition to 64-bit little-endian files.
GitOrigin-RevId: 611c62b30d160375b46b7afedc04965ee6f67d1a
diff --git a/libomptarget/plugins-nextgen/common/include/GlobalHandler.h b/libomptarget/plugins-nextgen/common/include/GlobalHandler.h
index 5c76799..829b4b7 100644
--- a/libomptarget/plugins-nextgen/common/include/GlobalHandler.h
+++ b/libomptarget/plugins-nextgen/common/include/GlobalHandler.h
@@ -104,7 +104,7 @@
virtual ~GenericGlobalHandlerTy() {}
/// Helper function for getting an ELF from a device image.
- Expected<ELF64LEObjectFile> getELFObjectFile(DeviceImageTy &Image);
+ Expected<std::unique_ptr<ObjectFile>> getELFObjectFile(DeviceImageTy &Image);
/// Returns whether the symbol named \p SymName is present in the given \p
/// Image.
diff --git a/libomptarget/plugins-nextgen/common/include/Utils/ELF.h b/libomptarget/plugins-nextgen/common/include/Utils/ELF.h
index 140a6b6..88c83d3 100644
--- a/libomptarget/plugins-nextgen/common/include/Utils/ELF.h
+++ b/libomptarget/plugins-nextgen/common/include/Utils/ELF.h
@@ -28,17 +28,15 @@
llvm::Expected<bool> checkMachine(llvm::StringRef Object, uint16_t EMachine);
/// Returns a pointer to the given \p Symbol inside of an ELF object.
-llvm::Expected<const void *> getSymbolAddress(
- const llvm::object::ELFObjectFile<llvm::object::ELF64LE> &ELFObj,
- const llvm::object::ELF64LE::Sym &Symbol);
+llvm::Expected<const void *>
+getSymbolAddress(const llvm::object::ELFSymbolRef &Symbol);
/// Returns the symbol associated with the \p Name in the \p ELFObj. It will
/// first search for the hash sections to identify symbols from the hash table.
/// If that fails it will fall back to a linear search in the case of an
/// executable file without a hash table.
-llvm::Expected<const typename llvm::object::ELF64LE::Sym *>
-getSymbol(const llvm::object::ELFObjectFile<llvm::object::ELF64LE> &ELFObj,
- llvm::StringRef Name);
+llvm::Expected<std::optional<llvm::object::ELFSymbolRef>>
+getSymbol(const llvm::object::ObjectFile &ELFObj, llvm::StringRef Name);
} // namespace elf
} // namespace utils
diff --git a/libomptarget/plugins-nextgen/common/src/GlobalHandler.cpp b/libomptarget/plugins-nextgen/common/src/GlobalHandler.cpp
index d398f60..213f861 100644
--- a/libomptarget/plugins-nextgen/common/src/GlobalHandler.cpp
+++ b/libomptarget/plugins-nextgen/common/src/GlobalHandler.cpp
@@ -25,14 +25,12 @@
using namespace target;
using namespace plugin;
-Expected<ELF64LEObjectFile>
+Expected<std::unique_ptr<ObjectFile>>
GenericGlobalHandlerTy::getELFObjectFile(DeviceImageTy &Image) {
assert(utils::elf::isELF(Image.getMemoryBuffer().getBuffer()) &&
"Input is not an ELF file");
- Expected<ELF64LEObjectFile> ElfOrErr =
- ELF64LEObjectFile::create(Image.getMemoryBuffer());
- return ElfOrErr;
+ return ELFObjectFileBase::createELFObjectFile(Image.getMemoryBuffer());
}
Error GenericGlobalHandlerTy::moveGlobalBetweenDeviceAndHost(
@@ -91,13 +89,13 @@
}
// Search the ELF symbol using the symbol name.
- auto SymOrErr = utils::elf::getSymbol(*ELFObjOrErr, SymName);
+ auto SymOrErr = utils::elf::getSymbol(**ELFObjOrErr, SymName);
if (!SymOrErr) {
consumeError(SymOrErr.takeError());
return false;
}
- return *SymOrErr;
+ return SymOrErr->has_value();
}
Error GenericGlobalHandlerTy::getGlobalMetadataFromImage(
@@ -110,7 +108,7 @@
return ELFObj.takeError();
// Search the ELF symbol using the symbol name.
- auto SymOrErr = utils::elf::getSymbol(*ELFObj, ImageGlobal.getName());
+ auto SymOrErr = utils::elf::getSymbol(**ELFObj, ImageGlobal.getName());
if (!SymOrErr)
return Plugin::error("Failed ELF lookup of global '%s': %s",
ImageGlobal.getName().data(),
@@ -120,7 +118,7 @@
return Plugin::error("Failed to find global symbol '%s' in the ELF image",
ImageGlobal.getName().data());
- auto AddrOrErr = utils::elf::getSymbolAddress(*ELFObj, **SymOrErr);
+ auto AddrOrErr = utils::elf::getSymbolAddress(**SymOrErr);
// Get the section to which the symbol belongs.
if (!AddrOrErr)
return Plugin::error("Failed to get ELF symbol from global '%s': %s",
@@ -129,7 +127,7 @@
// Setup the global symbol's address and size.
ImageGlobal.setPtr(const_cast<void *>(*AddrOrErr));
- ImageGlobal.setSize((*SymOrErr)->st_size);
+ ImageGlobal.setSize((*SymOrErr)->getSize());
return Plugin::success();
}
diff --git a/libomptarget/plugins-nextgen/common/src/Utils/ELF.cpp b/libomptarget/plugins-nextgen/common/src/Utils/ELF.cpp
index c84c3ba..c6d1bff 100644
--- a/libomptarget/plugins-nextgen/common/src/Utils/ELF.cpp
+++ b/libomptarget/plugins-nextgen/common/src/Utils/ELF.cpp
@@ -36,18 +36,10 @@
}
}
-Expected<bool> utils::elf::checkMachine(StringRef Object, uint16_t EMachine) {
- assert(isELF(Object) && "Input is not an ELF!");
-
- Expected<ELF64LEObjectFile> ElfOrErr =
- ELF64LEObjectFile::create(MemoryBufferRef(Object, /*Identifier=*/""),
- /*InitContent=*/false);
- if (!ElfOrErr)
- return ElfOrErr.takeError();
-
- const auto Header = ElfOrErr->getELFFile().getHeader();
- if (Header.e_ident[EI_CLASS] != ELFCLASS64)
- return createError("Only 64-bit ELF files are supported");
+template <class ELFT>
+static Expected<bool>
+checkMachineImpl(const object::ELFObjectFile<ELFT> &ELFObj, uint16_t EMachine) {
+ const auto Header = ELFObj.getELFFile().getHeader();
if (Header.e_type != ET_EXEC && Header.e_type != ET_DYN)
return createError("Only executable ELF files are supported");
@@ -71,6 +63,25 @@
return Header.e_machine == EMachine;
}
+Expected<bool> utils::elf::checkMachine(StringRef Object, uint16_t EMachine) {
+ assert(isELF(Object) && "Input is not an ELF!");
+
+ Expected<std::unique_ptr<ObjectFile>> ElfOrErr =
+ ObjectFile::createELFObjectFile(
+ MemoryBufferRef(Object, /*Identifier=*/""),
+ /*InitContent=*/false);
+ if (!ElfOrErr)
+ return ElfOrErr.takeError();
+
+ if (const ELF64LEObjectFile *ELFObj =
+ dyn_cast<ELF64LEObjectFile>(&**ElfOrErr))
+ return checkMachineImpl(*ELFObj, EMachine);
+ if (const ELF64BEObjectFile *ELFObj =
+ dyn_cast<ELF64BEObjectFile>(&**ElfOrErr))
+ return checkMachineImpl(*ELFObj, EMachine);
+ return createError("Only 64-bit ELF files are supported");
+}
+
template <class ELFT>
static Expected<const typename ELFT::Sym *>
getSymbolFromGnuHashTable(StringRef Name, const typename ELFT::GnuHash &HashTab,
@@ -138,9 +149,10 @@
}
template <class ELFT>
-static Expected<const typename ELFT::Sym *>
-getHashTableSymbol(const ELFFile<ELFT> &Elf, const typename ELFT::Shdr &Sec,
- StringRef Name) {
+static Expected<std::optional<ELFSymbolRef>>
+getHashTableSymbol(const ELFObjectFile<ELFT> &ELFObj,
+ const typename ELFT::Shdr &Sec, StringRef Name) {
+ const ELFFile<ELFT> &Elf = ELFObj.getELFFile();
if (Sec.sh_type != ELF::SHT_HASH && Sec.sh_type != ELF::SHT_GNU_HASH)
return createError(
"invalid sh_type for hash table, expected SHT_HASH or SHT_GNU_HASH");
@@ -179,7 +191,10 @@
sizeof(typename ELFT::Word) * HashTab->nbuckets +
sizeof(typename ELFT::Word) * (SymTab.size() - HashTab->symndx))
return createError("section has invalid sh_size: " + Twine(Sec.sh_size));
- return getSymbolFromGnuHashTable<ELFT>(Name, *HashTab, SymTab, StrTab);
+ auto Sym = getSymbolFromGnuHashTable<ELFT>(Name, *HashTab, SymTab, StrTab);
+ if (!Sym)
+ return Sym.takeError();
+ return ELFObj.toSymbolRef(*SymTabOrErr, *Sym - &SymTab[0]);
}
// If this is a Sys-V hash table we verify its size and search the symbol
@@ -197,16 +212,20 @@
sizeof(typename ELFT::Word) * HashTab->nchain)
return createError("section has invalid sh_size: " + Twine(Sec.sh_size));
- return getSymbolFromSysVHashTable<ELFT>(Name, *HashTab, SymTab, StrTab);
+ auto Sym = getSymbolFromSysVHashTable<ELFT>(Name, *HashTab, SymTab, StrTab);
+ if (!Sym)
+ return Sym.takeError();
+ return ELFObj.toSymbolRef(*SymTabOrErr, *Sym - &SymTab[0]);
}
- return nullptr;
+ return std::nullopt;
}
template <class ELFT>
-static Expected<const typename ELFT::Sym *>
-getSymTableSymbol(const ELFFile<ELFT> &Elf, const typename ELFT::Shdr &Sec,
- StringRef Name) {
+static Expected<std::optional<ELFSymbolRef>>
+getSymTableSymbol(const ELFObjectFile<ELFT> &ELFObj,
+ const typename ELFT::Shdr &Sec, StringRef Name) {
+ const ELFFile<ELFT> &Elf = ELFObj.getELFFile();
if (Sec.sh_type != ELF::SHT_SYMTAB && Sec.sh_type != ELF::SHT_DYNSYM)
return createError(
"invalid sh_type for hash table, expected SHT_SYMTAB or SHT_DYNSYM");
@@ -226,13 +245,14 @@
for (const typename ELFT::Sym &Sym : SymTab)
if (StrTab.drop_front(Sym.st_name).data() == Name)
- return &Sym;
+ return ELFObj.toSymbolRef(&Sec, &Sym - &SymTab[0]);
- return nullptr;
+ return std::nullopt;
}
-Expected<const typename ELF64LE::Sym *>
-utils::elf::getSymbol(const ELFObjectFile<ELF64LE> &ELFObj, StringRef Name) {
+template <class ELFT>
+static Expected<std::optional<ELFSymbolRef>>
+getSymbolImpl(const ELFObjectFile<ELFT> &ELFObj, StringRef Name) {
// First try to look up the symbol via the hash table.
for (ELFSectionRef Sec : ELFObj.sections()) {
if (Sec.getType() != SHT_HASH && Sec.getType() != SHT_GNU_HASH)
@@ -241,8 +261,7 @@
auto HashTabOrErr = ELFObj.getELFFile().getSection(Sec.getIndex());
if (!HashTabOrErr)
return HashTabOrErr.takeError();
- return getHashTableSymbol<ELF64LE>(ELFObj.getELFFile(), **HashTabOrErr,
- Name);
+ return getHashTableSymbol<ELFT>(ELFObj, **HashTabOrErr, Name);
}
// If this is an executable file check the entire standard symbol table.
@@ -253,16 +272,31 @@
auto SymTabOrErr = ELFObj.getELFFile().getSection(Sec.getIndex());
if (!SymTabOrErr)
return SymTabOrErr.takeError();
- return getSymTableSymbol<ELF64LE>(ELFObj.getELFFile(), **SymTabOrErr, Name);
+ return getSymTableSymbol<ELFT>(ELFObj, **SymTabOrErr, Name);
}
- return nullptr;
+ return std::nullopt;
}
-Expected<const void *> utils::elf::getSymbolAddress(
- const object::ELFObjectFile<object::ELF64LE> &ELFObj,
- const object::ELF64LE::Sym &Symbol) {
- const ELFFile<ELF64LE> &ELFFile = ELFObj.getELFFile();
+Expected<std::optional<ELFSymbolRef>>
+utils::elf::getSymbol(const ObjectFile &Obj, StringRef Name) {
+ if (const ELF64LEObjectFile *ELFObj = dyn_cast<ELF64LEObjectFile>(&Obj))
+ return getSymbolImpl(*ELFObj, Name);
+ if (const ELF64BEObjectFile *ELFObj = dyn_cast<ELF64BEObjectFile>(&Obj))
+ return getSymbolImpl(*ELFObj, Name);
+ return createError("Only 64-bit ELF files are supported");
+}
+
+template <class ELFT>
+static Expected<const void *>
+getSymbolAddressImpl(const ELFObjectFile<ELFT> &ELFObj,
+ const ELFSymbolRef &SymRef) {
+ const ELFFile<ELFT> &ELFFile = ELFObj.getELFFile();
+
+ auto SymOrErr = ELFObj.getSymbol(SymRef.getRawDataRefImpl());
+ if (!SymOrErr)
+ return SymOrErr.takeError();
+ const auto &Symbol = **SymOrErr;
auto SecOrErr = ELFFile.getSection(Symbol.st_shndx);
if (!SecOrErr)
@@ -283,3 +317,13 @@
return ELFFile.base() + Offset;
}
+
+Expected<const void *>
+utils::elf::getSymbolAddress(const ELFSymbolRef &SymRef) {
+ const ObjectFile *Obj = SymRef.getObject();
+ if (const ELF64LEObjectFile *ELFObj = dyn_cast<ELF64LEObjectFile>(Obj))
+ return getSymbolAddressImpl(*ELFObj, SymRef);
+ if (const ELF64BEObjectFile *ELFObj = dyn_cast<ELF64BEObjectFile>(Obj))
+ return getSymbolAddressImpl(*ELFObj, SymRef);
+ return createError("Only 64-bit ELF files are supported");
+}
diff --git a/libomptarget/plugins-nextgen/cuda/src/rtl.cpp b/libomptarget/plugins-nextgen/cuda/src/rtl.cpp
index f85a00c..b862bc7 100644
--- a/libomptarget/plugins-nextgen/cuda/src/rtl.cpp
+++ b/libomptarget/plugins-nextgen/cuda/src/rtl.cpp
@@ -1166,7 +1166,7 @@
// Search for all symbols that contain a constructor or destructor.
SmallVector<std::pair<StringRef, uint16_t>> Funcs;
- for (ELFSymbolRef Sym : ELFObjOrErr->symbols()) {
+ for (ELFSymbolRef Sym : (*ELFObjOrErr)->symbols()) {
auto NameOrErr = Sym.getName();
if (!NameOrErr)
return NameOrErr.takeError();
