Fix ARM program header values used for exidx.
Before, I was using p_vaddr to get the offset into the elf file where
the exidx frame starts. I changed that to use p_offset since this already
has the load bias offset in it and some elf files do not set p_vaddr
properly.
Also, use p_filesz instead of p_memsz, since again, some elf files do
not set p_memsz to the same as p_filesz.
Bug: 110704153
Test: All libbacktrace/libunwindstack unit tests pass.
Test: Randomly unwind process on a walleye.
Test: Verified that this properly dumps and unwinds the shared
Test: library that sets p_vaddr and p_memsz differently.
Change-Id: Ic7b1e5d07439f4636fa02cd884a8727a5737372b
diff --git a/libunwindstack/ElfInterface.cpp b/libunwindstack/ElfInterface.cpp
index 954a821..915cddb 100644
--- a/libunwindstack/ElfInterface.cpp
+++ b/libunwindstack/ElfInterface.cpp
@@ -211,7 +211,7 @@
return false;
}
- if (HandleType(offset, phdr.p_type, *load_bias)) {
+ if (HandleType(offset, phdr.p_type)) {
continue;
}
diff --git a/libunwindstack/ElfInterfaceArm.cpp b/libunwindstack/ElfInterfaceArm.cpp
index 9b61599..a3244e8 100644
--- a/libunwindstack/ElfInterfaceArm.cpp
+++ b/libunwindstack/ElfInterfaceArm.cpp
@@ -87,20 +87,22 @@
#define PT_ARM_EXIDX 0x70000001
#endif
-bool ElfInterfaceArm::HandleType(uint64_t offset, uint32_t type, uint64_t load_bias) {
+bool ElfInterfaceArm::HandleType(uint64_t offset, uint32_t type) {
if (type != PT_ARM_EXIDX) {
return false;
}
Elf32_Phdr phdr;
- if (!memory_->ReadField(offset, &phdr, &phdr.p_vaddr, sizeof(phdr.p_vaddr))) {
+ if (!memory_->ReadFully(offset, &phdr, sizeof(phdr))) {
return true;
}
- if (!memory_->ReadField(offset, &phdr, &phdr.p_memsz, sizeof(phdr.p_memsz))) {
- return true;
- }
- start_offset_ = phdr.p_vaddr - load_bias;
- total_entries_ = phdr.p_memsz / 8;
+
+ // The offset already takes into account the load bias.
+ start_offset_ = phdr.p_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;
}
diff --git a/libunwindstack/ElfInterfaceArm.h b/libunwindstack/ElfInterfaceArm.h
index 18efb6c..3bee9cf 100644
--- a/libunwindstack/ElfInterfaceArm.h
+++ b/libunwindstack/ElfInterfaceArm.h
@@ -70,7 +70,7 @@
bool FindEntry(uint32_t pc, uint64_t* entry_offset);
- bool HandleType(uint64_t offset, uint32_t type, uint64_t load_bias) override;
+ bool HandleType(uint64_t offset, uint32_t type) override;
bool Step(uint64_t pc, Regs* regs, Memory* process_memory, bool* finished) override;
diff --git a/libunwindstack/include/unwindstack/ElfInterface.h b/libunwindstack/include/unwindstack/ElfInterface.h
index 4d25c40..0c588da 100644
--- a/libunwindstack/include/unwindstack/ElfInterface.h
+++ b/libunwindstack/include/unwindstack/ElfInterface.h
@@ -118,7 +118,7 @@
template <typename SymType>
bool GetGlobalVariableWithTemplate(const std::string& name, uint64_t* memory_address);
- virtual bool HandleType(uint64_t, uint32_t, uint64_t) { return false; }
+ virtual bool HandleType(uint64_t, uint32_t) { return false; }
template <typename EhdrType>
static void GetMaxSizeWithTemplate(Memory* memory, uint64_t* size);
diff --git a/libunwindstack/tests/ElfInterfaceArmTest.cpp b/libunwindstack/tests/ElfInterfaceArmTest.cpp
index 5f1c2ac..a8bb4aa 100644
--- a/libunwindstack/tests/ElfInterfaceArmTest.cpp
+++ b/libunwindstack/tests/ElfInterfaceArmTest.cpp
@@ -245,56 +245,41 @@
TEST_F(ElfInterfaceArmTest, HandleType_not_arm_exidx) {
ElfInterfaceArmFake interface(&memory_);
- ASSERT_FALSE(interface.HandleType(0x1000, PT_NULL, 0));
- ASSERT_FALSE(interface.HandleType(0x1000, PT_LOAD, 0));
- ASSERT_FALSE(interface.HandleType(0x1000, PT_DYNAMIC, 0));
- ASSERT_FALSE(interface.HandleType(0x1000, PT_INTERP, 0));
- ASSERT_FALSE(interface.HandleType(0x1000, PT_NOTE, 0));
- ASSERT_FALSE(interface.HandleType(0x1000, PT_SHLIB, 0));
- ASSERT_FALSE(interface.HandleType(0x1000, PT_PHDR, 0));
- ASSERT_FALSE(interface.HandleType(0x1000, PT_TLS, 0));
- ASSERT_FALSE(interface.HandleType(0x1000, PT_LOOS, 0));
- ASSERT_FALSE(interface.HandleType(0x1000, PT_HIOS, 0));
- ASSERT_FALSE(interface.HandleType(0x1000, PT_LOPROC, 0));
- ASSERT_FALSE(interface.HandleType(0x1000, PT_HIPROC, 0));
- ASSERT_FALSE(interface.HandleType(0x1000, PT_GNU_EH_FRAME, 0));
- ASSERT_FALSE(interface.HandleType(0x1000, PT_GNU_STACK, 0));
+ 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;
+ Elf32_Phdr phdr = {};
interface.FakeSetStartOffset(0x1000);
interface.FakeSetTotalEntries(100);
- phdr.p_vaddr = 0x2000;
- phdr.p_memsz = 0xa00;
+ 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, 0));
- ASSERT_EQ(0x1000U, interface.start_offset());
- ASSERT_EQ(100U, interface.total_entries());
-
- // Verify that if the second read fails, we still don't set the values.
- memory_.SetData32(
- 0x1000 + reinterpret_cast<uint64_t>(&phdr.p_vaddr) - reinterpret_cast<uint64_t>(&phdr),
- phdr.p_vaddr);
- ASSERT_TRUE(interface.HandleType(0x1000, 0x70000001, 0));
+ ASSERT_TRUE(interface.HandleType(0x1000, 0x70000001));
ASSERT_EQ(0x1000U, interface.start_offset());
ASSERT_EQ(100U, interface.total_entries());
// Everything is correct and present.
- memory_.SetData32(
- 0x1000 + reinterpret_cast<uint64_t>(&phdr.p_memsz) - reinterpret_cast<uint64_t>(&phdr),
- phdr.p_memsz);
- ASSERT_TRUE(interface.HandleType(0x1000, 0x70000001, 0));
+ memory_.SetMemory(0x1000, &phdr, sizeof(phdr));
+ ASSERT_TRUE(interface.HandleType(0x1000, 0x70000001));
ASSERT_EQ(0x2000U, interface.start_offset());
ASSERT_EQ(320U, interface.total_entries());
-
- // Non-zero load bias.
- ASSERT_TRUE(interface.HandleType(0x1000, 0x70000001, 0x1000));
- ASSERT_EQ(0x1000U, interface.start_offset());
- ASSERT_EQ(320U, interface.total_entries());
}
TEST_F(ElfInterfaceArmTest, StepExidx) {
diff --git a/libunwindstack/tests/ElfInterfaceTest.cpp b/libunwindstack/tests/ElfInterfaceTest.cpp
index 4008e9b..487d39c 100644
--- a/libunwindstack/tests/ElfInterfaceTest.cpp
+++ b/libunwindstack/tests/ElfInterfaceTest.cpp
@@ -116,8 +116,7 @@
template <typename Sym>
void ElfInterfaceTest::InitSym(uint64_t offset, uint32_t value, uint32_t size, uint32_t name_offset,
uint64_t sym_offset, const char* name) {
- Sym sym;
- memset(&sym, 0, sizeof(sym));
+ Sym sym = {};
sym.st_info = STT_FUNC;
sym.st_value = value;
sym.st_size = size;
@@ -132,15 +131,13 @@
void ElfInterfaceTest::SinglePtLoad() {
std::unique_ptr<ElfInterface> elf(new ElfInterfaceType(&memory_));
- Ehdr ehdr;
- memset(&ehdr, 0, sizeof(ehdr));
+ Ehdr ehdr = {};
ehdr.e_phoff = 0x100;
ehdr.e_phnum = 1;
ehdr.e_phentsize = sizeof(Phdr);
memory_.SetMemory(0, &ehdr, sizeof(ehdr));
- Phdr phdr;
- memset(&phdr, 0, sizeof(phdr));
+ Phdr phdr = {};
phdr.p_type = PT_LOAD;
phdr.p_vaddr = 0x2000;
phdr.p_memsz = 0x10000;
@@ -172,15 +169,13 @@
void ElfInterfaceTest::MultipleExecutablePtLoads() {
std::unique_ptr<ElfInterface> elf(new ElfInterfaceType(&memory_));
- Ehdr ehdr;
- memset(&ehdr, 0, sizeof(ehdr));
+ Ehdr ehdr = {};
ehdr.e_phoff = 0x100;
ehdr.e_phnum = 3;
ehdr.e_phentsize = sizeof(Phdr);
memory_.SetMemory(0, &ehdr, sizeof(ehdr));
- Phdr phdr;
- memset(&phdr, 0, sizeof(phdr));
+ Phdr phdr = {};
phdr.p_type = PT_LOAD;
phdr.p_vaddr = 0x2000;
phdr.p_memsz = 0x10000;
@@ -241,15 +236,13 @@
void ElfInterfaceTest::MultipleExecutablePtLoadsIncrementsNotSizeOfPhdr() {
std::unique_ptr<ElfInterface> elf(new ElfInterfaceType(&memory_));
- Ehdr ehdr;
- memset(&ehdr, 0, sizeof(ehdr));
+ Ehdr ehdr = {};
ehdr.e_phoff = 0x100;
ehdr.e_phnum = 3;
ehdr.e_phentsize = sizeof(Phdr) + 100;
memory_.SetMemory(0, &ehdr, sizeof(ehdr));
- Phdr phdr;
- memset(&phdr, 0, sizeof(phdr));
+ Phdr phdr = {};
phdr.p_type = PT_LOAD;
phdr.p_vaddr = 0x2000;
phdr.p_memsz = 0x10000;
@@ -312,15 +305,13 @@
void ElfInterfaceTest::NonExecutablePtLoads() {
std::unique_ptr<ElfInterface> elf(new ElfInterfaceType(&memory_));
- Ehdr ehdr;
- memset(&ehdr, 0, sizeof(ehdr));
+ Ehdr ehdr = {};
ehdr.e_phoff = 0x100;
ehdr.e_phnum = 3;
ehdr.e_phentsize = sizeof(Phdr);
memory_.SetMemory(0, &ehdr, sizeof(ehdr));
- Phdr phdr;
- memset(&phdr, 0, sizeof(phdr));
+ Phdr phdr = {};
phdr.p_type = PT_LOAD;
phdr.p_vaddr = 0x2000;
phdr.p_memsz = 0x10000;
@@ -371,17 +362,15 @@
void ElfInterfaceTest::ManyPhdrs() {
std::unique_ptr<ElfInterface> elf(new ElfInterfaceType(&memory_));
- Ehdr ehdr;
- memset(&ehdr, 0, sizeof(ehdr));
+ Ehdr ehdr = {};
ehdr.e_phoff = 0x100;
ehdr.e_phnum = 7;
ehdr.e_phentsize = sizeof(Phdr);
memory_.SetMemory(0, &ehdr, sizeof(ehdr));
- Phdr phdr;
uint64_t phdr_offset = 0x100;
- memset(&phdr, 0, sizeof(phdr));
+ Phdr phdr = {};
phdr.p_type = PT_LOAD;
phdr.p_vaddr = 0x2000;
phdr.p_memsz = 0x10000;
@@ -444,18 +433,16 @@
TEST_F(ElfInterfaceTest, elf32_arm) {
ElfInterfaceArm elf_arm(&memory_);
- Elf32_Ehdr ehdr;
- memset(&ehdr, 0, sizeof(ehdr));
+ Elf32_Ehdr ehdr = {};
ehdr.e_phoff = 0x100;
ehdr.e_phnum = 1;
ehdr.e_phentsize = sizeof(Elf32_Phdr);
memory_.SetMemory(0, &ehdr, sizeof(ehdr));
- Elf32_Phdr phdr;
- memset(&phdr, 0, sizeof(phdr));
+ Elf32_Phdr phdr = {};
phdr.p_type = PT_ARM_EXIDX;
- phdr.p_vaddr = 0x2000;
- phdr.p_memsz = 16;
+ phdr.p_offset = 0x2000;
+ phdr.p_filesz = 16;
memory_.SetMemory(0x100, &phdr, sizeof(phdr));
// Add arm exidx entries.
@@ -480,8 +467,7 @@
template <typename Ehdr, typename Phdr, typename Shdr, typename Dyn>
void ElfInterfaceTest::SonameInit(SonameTestEnum test_type) {
- Ehdr ehdr;
- memset(&ehdr, 0, sizeof(ehdr));
+ Ehdr ehdr = {};
ehdr.e_shoff = 0x200;
ehdr.e_shnum = 2;
ehdr.e_shentsize = sizeof(Shdr);
@@ -490,8 +476,7 @@
ehdr.e_phentsize = sizeof(Phdr);
memory_.SetMemory(0, &ehdr, sizeof(ehdr));
- Shdr shdr;
- memset(&shdr, 0, sizeof(shdr));
+ Shdr shdr = {};
shdr.sh_type = SHT_STRTAB;
if (test_type == SONAME_MISSING_MAP) {
shdr.sh_addr = 0x20100;
@@ -501,8 +486,7 @@
shdr.sh_offset = 0x10000;
memory_.SetMemory(0x200 + sizeof(shdr), &shdr, sizeof(shdr));
- Phdr phdr;
- memset(&phdr, 0, sizeof(phdr));
+ Phdr phdr = {};
phdr.p_type = PT_DYNAMIC;
phdr.p_offset = 0x2000;
phdr.p_memsz = sizeof(Dyn) * 3;
@@ -748,8 +732,7 @@
void ElfInterfaceTest::InitSectionHeadersMalformed() {
std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));
- Ehdr ehdr;
- memset(&ehdr, 0, sizeof(ehdr));
+ Ehdr ehdr = {};
ehdr.e_shoff = 0x1000;
ehdr.e_shnum = 10;
ehdr.e_shentsize = sizeof(Shdr);
@@ -774,8 +757,7 @@
uint64_t offset = 0x1000;
- Ehdr ehdr;
- memset(&ehdr, 0, sizeof(ehdr));
+ Ehdr ehdr = {};
ehdr.e_shoff = offset;
ehdr.e_shnum = 10;
ehdr.e_shentsize = entry_size;
@@ -783,8 +765,7 @@
offset += ehdr.e_shentsize;
- Shdr shdr;
- memset(&shdr, 0, sizeof(shdr));
+ Shdr shdr = {};
shdr.sh_type = SHT_SYMTAB;
shdr.sh_link = 4;
shdr.sh_addr = 0x5000;
@@ -863,8 +844,7 @@
uint64_t offset = 0x2000;
- Ehdr ehdr;
- memset(&ehdr, 0, sizeof(ehdr));
+ Ehdr ehdr = {};
ehdr.e_shoff = offset;
ehdr.e_shnum = 10;
ehdr.e_shentsize = sizeof(Shdr);
@@ -873,8 +853,7 @@
offset += ehdr.e_shentsize;
- Shdr shdr;
- memset(&shdr, 0, sizeof(shdr));
+ Shdr shdr = {};
shdr.sh_type = SHT_PROGBITS;
shdr.sh_link = 2;
shdr.sh_name = 0x200;
@@ -956,15 +935,13 @@
TEST_F(ElfInterfaceTest, is_valid_pc_from_pt_load) {
std::unique_ptr<ElfInterface> elf(new ElfInterface32(&memory_));
- Elf32_Ehdr ehdr;
- memset(&ehdr, 0, sizeof(ehdr));
+ Elf32_Ehdr ehdr = {};
ehdr.e_phoff = 0x100;
ehdr.e_phnum = 1;
ehdr.e_phentsize = sizeof(Elf32_Phdr);
memory_.SetMemory(0, &ehdr, sizeof(ehdr));
- Elf32_Phdr phdr;
- memset(&phdr, 0, sizeof(phdr));
+ Elf32_Phdr phdr = {};
phdr.p_type = PT_LOAD;
phdr.p_vaddr = 0;
phdr.p_memsz = 0x10000;
@@ -984,15 +961,13 @@
TEST_F(ElfInterfaceTest, is_valid_pc_from_pt_load_non_zero_load_bias) {
std::unique_ptr<ElfInterface> elf(new ElfInterface32(&memory_));
- Elf32_Ehdr ehdr;
- memset(&ehdr, 0, sizeof(ehdr));
+ Elf32_Ehdr ehdr = {};
ehdr.e_phoff = 0x100;
ehdr.e_phnum = 1;
ehdr.e_phentsize = sizeof(Elf32_Phdr);
memory_.SetMemory(0, &ehdr, sizeof(ehdr));
- Elf32_Phdr phdr;
- memset(&phdr, 0, sizeof(phdr));
+ Elf32_Phdr phdr = {};
phdr.p_type = PT_LOAD;
phdr.p_vaddr = 0x2000;
phdr.p_memsz = 0x10000;
@@ -1017,16 +992,14 @@
uint64_t sh_offset = 0x100;
- Elf32_Ehdr ehdr;
- memset(&ehdr, 0, sizeof(ehdr));
+ Elf32_Ehdr ehdr = {};
ehdr.e_shstrndx = 1;
ehdr.e_shoff = sh_offset;
ehdr.e_shentsize = sizeof(Elf32_Shdr);
ehdr.e_shnum = 3;
memory_.SetMemory(0, &ehdr, sizeof(ehdr));
- Elf32_Shdr shdr;
- memset(&shdr, 0, sizeof(shdr));
+ Elf32_Shdr shdr = {};
shdr.sh_type = SHT_NULL;
memory_.SetMemory(sh_offset, &shdr, sizeof(shdr));
@@ -1080,16 +1053,14 @@
uint64_t sh_offset = 0x100;
- Elf32_Ehdr ehdr;
- memset(&ehdr, 0, sizeof(ehdr));
+ Elf32_Ehdr ehdr = {};
ehdr.e_shstrndx = 1;
ehdr.e_shoff = sh_offset;
ehdr.e_shentsize = sizeof(Elf32_Shdr);
ehdr.e_shnum = 3;
memory_.SetMemory(0, &ehdr, sizeof(ehdr));
- Elf32_Shdr shdr;
- memset(&shdr, 0, sizeof(shdr));
+ Elf32_Shdr shdr = {};
shdr.sh_type = SHT_NULL;
memory_.SetMemory(sh_offset, &shdr, sizeof(shdr));