Merge "Remove Memory::ReadField."

This commit is contained in:
Christopher Ferris 2018-07-12 22:37:18 +00:00 committed by Gerrit Code Review
commit 5dce8ce747
7 changed files with 18 additions and 150 deletions

View file

@ -204,49 +204,19 @@ bool ElfInterface::ReadProgramHeaders(const EhdrType& ehdr, uint64_t* load_bias)
uint64_t offset = ehdr.e_phoff;
for (size_t i = 0; i < ehdr.e_phnum; i++, offset += ehdr.e_phentsize) {
PhdrType phdr;
if (!memory_->ReadField(offset, &phdr, &phdr.p_type, sizeof(phdr.p_type))) {
if (!memory_->ReadFully(offset, &phdr, sizeof(phdr))) {
last_error_.code = ERROR_MEMORY_INVALID;
last_error_.address =
offset + reinterpret_cast<uintptr_t>(&phdr.p_type) - reinterpret_cast<uintptr_t>(&phdr);
last_error_.address = offset;
return false;
}
if (HandleType(offset, phdr.p_type)) {
continue;
}
switch (phdr.p_type) {
case PT_LOAD:
{
// Get the flags first, if this isn't an executable header, ignore it.
if (!memory_->ReadField(offset, &phdr, &phdr.p_flags, sizeof(phdr.p_flags))) {
last_error_.code = ERROR_MEMORY_INVALID;
last_error_.address = offset + reinterpret_cast<uintptr_t>(&phdr.p_flags) -
reinterpret_cast<uintptr_t>(&phdr);
return false;
}
if ((phdr.p_flags & PF_X) == 0) {
continue;
}
if (!memory_->ReadField(offset, &phdr, &phdr.p_vaddr, sizeof(phdr.p_vaddr))) {
last_error_.code = ERROR_MEMORY_INVALID;
last_error_.address = offset + reinterpret_cast<uintptr_t>(&phdr.p_vaddr) -
reinterpret_cast<uintptr_t>(&phdr);
return false;
}
if (!memory_->ReadField(offset, &phdr, &phdr.p_offset, sizeof(phdr.p_offset))) {
last_error_.code = ERROR_MEMORY_INVALID;
last_error_.address = offset + reinterpret_cast<uintptr_t>(&phdr.p_offset) -
reinterpret_cast<uintptr_t>(&phdr);
return false;
}
if (!memory_->ReadField(offset, &phdr, &phdr.p_memsz, sizeof(phdr.p_memsz))) {
last_error_.code = ERROR_MEMORY_INVALID;
last_error_.address = offset + reinterpret_cast<uintptr_t>(&phdr.p_memsz) -
reinterpret_cast<uintptr_t>(&phdr);
return false;
}
pt_loads_[phdr.p_offset] = LoadInfo{phdr.p_offset, phdr.p_vaddr,
static_cast<size_t>(phdr.p_memsz)};
if (phdr.p_offset == 0) {
@ -256,46 +226,20 @@ bool ElfInterface::ReadProgramHeaders(const EhdrType& ehdr, uint64_t* load_bias)
}
case PT_GNU_EH_FRAME:
if (!memory_->ReadField(offset, &phdr, &phdr.p_offset, sizeof(phdr.p_offset))) {
last_error_.code = ERROR_MEMORY_INVALID;
last_error_.address = offset + reinterpret_cast<uintptr_t>(&phdr.p_offset) -
reinterpret_cast<uintptr_t>(&phdr);
return false;
}
// This is really the pointer to the .eh_frame_hdr section.
eh_frame_hdr_offset_ = phdr.p_offset;
if (!memory_->ReadField(offset, &phdr, &phdr.p_memsz, sizeof(phdr.p_memsz))) {
last_error_.code = ERROR_MEMORY_INVALID;
last_error_.address = offset + reinterpret_cast<uintptr_t>(&phdr.p_memsz) -
reinterpret_cast<uintptr_t>(&phdr);
return false;
}
eh_frame_hdr_size_ = phdr.p_memsz;
break;
case PT_DYNAMIC:
if (!memory_->ReadField(offset, &phdr, &phdr.p_offset, sizeof(phdr.p_offset))) {
last_error_.code = ERROR_MEMORY_INVALID;
last_error_.address = offset + reinterpret_cast<uintptr_t>(&phdr.p_offset) -
reinterpret_cast<uintptr_t>(&phdr);
return false;
}
dynamic_offset_ = phdr.p_offset;
if (!memory_->ReadField(offset, &phdr, &phdr.p_vaddr, sizeof(phdr.p_vaddr))) {
last_error_.code = ERROR_MEMORY_INVALID;
last_error_.address = offset + reinterpret_cast<uintptr_t>(&phdr.p_vaddr) -
reinterpret_cast<uintptr_t>(&phdr);
return false;
}
dynamic_vaddr_ = phdr.p_vaddr;
if (!memory_->ReadField(offset, &phdr, &phdr.p_memsz, sizeof(phdr.p_memsz))) {
last_error_.code = ERROR_MEMORY_INVALID;
last_error_.address = offset + reinterpret_cast<uintptr_t>(&phdr.p_memsz) -
reinterpret_cast<uintptr_t>(&phdr);
return false;
}
dynamic_size_ = phdr.p_memsz;
break;
default:
HandleUnknownType(phdr.p_type, phdr.p_offset, phdr.p_filesz);
break;
}
}
return true;
@ -313,8 +257,7 @@ bool ElfInterface::ReadSectionHeaders(const EhdrType& ehdr) {
ShdrType shdr;
if (ehdr.e_shstrndx < ehdr.e_shnum) {
uint64_t sh_offset = offset + ehdr.e_shstrndx * ehdr.e_shentsize;
if (memory_->ReadField(sh_offset, &shdr, &shdr.sh_offset, sizeof(shdr.sh_offset)) &&
memory_->ReadField(sh_offset, &shdr, &shdr.sh_size, sizeof(shdr.sh_size))) {
if (memory_->ReadFully(sh_offset, &shdr, sizeof(shdr))) {
sec_offset = shdr.sh_offset;
sec_size = shdr.sh_size;
}

View file

@ -87,23 +87,17 @@ bool ElfInterfaceArm::GetPrel31Addr(uint32_t offset, uint32_t* addr) {
#define PT_ARM_EXIDX 0x70000001
#endif
bool ElfInterfaceArm::HandleType(uint64_t offset, uint32_t type) {
void ElfInterfaceArm::HandleUnknownType(uint32_t type, uint64_t ph_offset, uint64_t ph_filesz) {
if (type != PT_ARM_EXIDX) {
return false;
}
Elf32_Phdr phdr;
if (!memory_->ReadFully(offset, &phdr, sizeof(phdr))) {
return true;
return;
}
// The offset already takes into account the load bias.
start_offset_ = phdr.p_offset;
start_offset_ = ph_offset;
// Always use filesz instead of memsz. In most cases they are the same,
// but some shared libraries wind up setting one correctly and not the other.
total_entries_ = phdr.p_filesz / 8;
return true;
total_entries_ = ph_filesz / 8;
}
bool ElfInterfaceArm::Step(uint64_t pc, Regs* regs, Memory* process_memory, bool* finished) {

View file

@ -70,7 +70,7 @@ class ElfInterfaceArm : public ElfInterface32 {
bool FindEntry(uint32_t pc, uint64_t* entry_offset);
bool HandleType(uint64_t offset, uint32_t type) override;
void HandleUnknownType(uint32_t type, uint64_t ph_offset, uint64_t ph_filesz) override;
bool Step(uint64_t pc, Regs* regs, Memory* process_memory, bool* finished) override;

View file

@ -118,7 +118,7 @@ class ElfInterface {
template <typename SymType>
bool GetGlobalVariableWithTemplate(const std::string& name, uint64_t* memory_address);
virtual bool HandleType(uint64_t, uint32_t) { return false; }
virtual void HandleUnknownType(uint32_t, uint64_t, uint64_t) {}
template <typename EhdrType>
static void GetMaxSizeWithTemplate(Memory* memory, uint64_t* size);

View file

@ -41,18 +41,6 @@ class Memory {
bool ReadFully(uint64_t addr, void* dst, size_t size);
inline bool ReadField(uint64_t addr, void* start, void* field, size_t size) {
if (reinterpret_cast<uintptr_t>(field) < reinterpret_cast<uintptr_t>(start)) {
return false;
}
uint64_t offset = reinterpret_cast<uintptr_t>(field) - reinterpret_cast<uintptr_t>(start);
if (__builtin_add_overflow(addr, offset, &offset)) {
return false;
}
// The read will check if offset + size overflows.
return ReadFully(offset, field, size);
}
inline bool Read32(uint64_t addr, uint32_t* dst) {
return ReadFully(addr, dst, sizeof(uint32_t));
}

View file

@ -242,44 +242,21 @@ TEST_F(ElfInterfaceArmTest, iterate) {
ASSERT_EQ(0xa020U, entries[4]);
}
TEST_F(ElfInterfaceArmTest, HandleType_not_arm_exidx) {
TEST_F(ElfInterfaceArmTest, HandleUnknownType_arm_exidx) {
ElfInterfaceArmFake interface(&memory_);
ASSERT_FALSE(interface.HandleType(0x1000, PT_NULL));
ASSERT_FALSE(interface.HandleType(0x1000, PT_LOAD));
ASSERT_FALSE(interface.HandleType(0x1000, PT_DYNAMIC));
ASSERT_FALSE(interface.HandleType(0x1000, PT_INTERP));
ASSERT_FALSE(interface.HandleType(0x1000, PT_NOTE));
ASSERT_FALSE(interface.HandleType(0x1000, PT_SHLIB));
ASSERT_FALSE(interface.HandleType(0x1000, PT_PHDR));
ASSERT_FALSE(interface.HandleType(0x1000, PT_TLS));
ASSERT_FALSE(interface.HandleType(0x1000, PT_LOOS));
ASSERT_FALSE(interface.HandleType(0x1000, PT_HIOS));
ASSERT_FALSE(interface.HandleType(0x1000, PT_LOPROC));
ASSERT_FALSE(interface.HandleType(0x1000, PT_HIPROC));
ASSERT_FALSE(interface.HandleType(0x1000, PT_GNU_EH_FRAME));
ASSERT_FALSE(interface.HandleType(0x1000, PT_GNU_STACK));
}
TEST_F(ElfInterfaceArmTest, HandleType_arm_exidx) {
ElfInterfaceArmFake interface(&memory_);
Elf32_Phdr phdr = {};
interface.FakeSetStartOffset(0x1000);
interface.FakeSetTotalEntries(100);
phdr.p_offset = 0x2000;
phdr.p_filesz = 0xa00;
// Verify that if reads fail, we don't set the values but still get true.
ASSERT_TRUE(interface.HandleType(0x1000, 0x70000001));
// Verify that if the type is not the one we want, we don't set the values.
interface.HandleUnknownType(0x70000000, 0x2000, 320);
ASSERT_EQ(0x1000U, interface.start_offset());
ASSERT_EQ(100U, interface.total_entries());
// Everything is correct and present.
memory_.SetMemory(0x1000, &phdr, sizeof(phdr));
ASSERT_TRUE(interface.HandleType(0x1000, 0x70000001));
interface.HandleUnknownType(0x70000001, 0x2000, 320);
ASSERT_EQ(0x2000U, interface.start_offset());
ASSERT_EQ(320U, interface.total_entries());
ASSERT_EQ(40U, interface.total_entries());
}
TEST_F(ElfInterfaceArmTest, StepExidx) {

View file

@ -51,40 +51,6 @@ struct FakeStruct {
uint64_t four;
};
TEST(MemoryTest, read_field) {
MemoryFakeAlwaysReadZero memory;
FakeStruct data;
memset(&data, 0xff, sizeof(data));
ASSERT_TRUE(memory.ReadField(0, &data, &data.one, sizeof(data.one)));
ASSERT_EQ(0, data.one);
memset(&data, 0xff, sizeof(data));
ASSERT_TRUE(memory.ReadField(0, &data, &data.two, sizeof(data.two)));
ASSERT_FALSE(data.two);
memset(&data, 0xff, sizeof(data));
ASSERT_TRUE(memory.ReadField(0, &data, &data.three, sizeof(data.three)));
ASSERT_EQ(0U, data.three);
memset(&data, 0xff, sizeof(data));
ASSERT_TRUE(memory.ReadField(0, &data, &data.four, sizeof(data.four)));
ASSERT_EQ(0U, data.four);
}
TEST(MemoryTest, read_field_fails) {
MemoryFakeAlwaysReadZero memory;
FakeStruct data;
memset(&data, 0xff, sizeof(data));
ASSERT_FALSE(memory.ReadField(UINT64_MAX, &data, &data.three, sizeof(data.three)));
// Field and start reversed, should fail.
ASSERT_FALSE(memory.ReadField(100, &data.two, &data, sizeof(data.two)));
ASSERT_FALSE(memory.ReadField(0, &data.two, &data, sizeof(data.two)));
}
TEST(MemoryTest, read_string) {
std::string name("string_in_memory");