Add section parsing and function name handling.

Add the code to parse the Elf section headers.

Add the plumbing through of all the symbol handling code.

Add tests for all of this new functionality.

Bug: 23762183

Test: Pass new unit tests.
Change-Id: Ie2d90cbb3d7653c53251dbcf34d9e5d241278377

1 files changed, 203 insertions, 0 deletions

diff --git a/libunwindstack/tests/ElfInterfaceTest.cpp b/libunwindstack/tests/ElfInterfaceTest.cpp
index 81cdaf5f0..0f56ba897 100644
--- a/libunwindstack/tests/ElfInterfaceTest.cpp
+++ b/libunwindstack/tests/ElfInterfaceTest.cpp
@@ -79,9 +79,37 @@ class ElfInterfaceTest : public ::testing::Test {
   template <typename ElfType>
   void InitHeadersDebugFrameFail();
 
+  template <typename Ehdr, typename Shdr, typename ElfInterfaceType>
+  void InitSectionHeadersMalformed();
+
+  template <typename Ehdr, typename Shdr, typename Sym, typename ElfInterfaceType>
+  void InitSectionHeaders(uint64_t entry_size);
+
+  template <typename Ehdr, typename Shdr, typename ElfInterfaceType>
+  void InitSectionHeadersOffsets();
+
+  template <typename Sym>
+  void InitSym(uint64_t offset, uint32_t value, uint32_t size, uint32_t name_offset,
+               uint64_t sym_offset, const char* name);
+
   MemoryFake memory_;
 };
 
+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.st_info = STT_FUNC;
+  sym.st_value = value;
+  sym.st_size = size;
+  sym.st_name = name_offset;
+  sym.st_shndx = SHN_COMMON;
+
+  memory_.SetMemory(offset, &sym, sizeof(sym));
+  memory_.SetMemory(sym_offset + name_offset, name, strlen(name) + 1);
+}
+
 template <typename Ehdr, typename Phdr, typename Dyn, typename ElfInterfaceType>
 void ElfInterfaceTest::SinglePtLoad() {
   std::unique_ptr<ElfInterface> elf(new ElfInterfaceType(&memory_));
@@ -718,3 +746,178 @@ TEST_F(ElfInterfaceTest, init_headers_debug_frame32_fail) {
 TEST_F(ElfInterfaceTest, init_headers_debug_frame64_fail) {
   InitHeadersDebugFrameFail<MockElfInterface64>();
 }
+
+template <typename Ehdr, typename Shdr, typename ElfInterfaceType>
+void ElfInterfaceTest::InitSectionHeadersMalformed() {
+  std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));
+
+  Ehdr ehdr;
+  memset(&ehdr, 0, sizeof(ehdr));
+  ehdr.e_shoff = 0x1000;
+  ehdr.e_shnum = 10;
+  ehdr.e_shentsize = sizeof(Shdr);
+  memory_.SetMemory(0, &ehdr, sizeof(ehdr));
+
+  ASSERT_TRUE(elf->Init());
+}
+
+TEST_F(ElfInterfaceTest, init_section_headers_malformed32) {
+  InitSectionHeadersMalformed<Elf32_Ehdr, Elf32_Shdr, ElfInterface32>();
+}
+
+TEST_F(ElfInterfaceTest, init_section_headers_malformed64) {
+  InitSectionHeadersMalformed<Elf64_Ehdr, Elf64_Shdr, ElfInterface64>();
+}
+
+template <typename Ehdr, typename Shdr, typename Sym, typename ElfInterfaceType>
+void ElfInterfaceTest::InitSectionHeaders(uint64_t entry_size) {
+  std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));
+
+  uint64_t offset = 0x1000;
+
+  Ehdr ehdr;
+  memset(&ehdr, 0, sizeof(ehdr));
+  ehdr.e_shoff = offset;
+  ehdr.e_shnum = 10;
+  ehdr.e_shentsize = entry_size;
+  memory_.SetMemory(0, &ehdr, sizeof(ehdr));
+
+  offset += ehdr.e_shentsize;
+
+  Shdr shdr;
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_SYMTAB;
+  shdr.sh_link = 4;
+  shdr.sh_addr = 0x5000;
+  shdr.sh_offset = 0x5000;
+  shdr.sh_entsize = sizeof(Sym);
+  shdr.sh_size = shdr.sh_entsize * 10;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_DYNSYM;
+  shdr.sh_link = 4;
+  shdr.sh_addr = 0x6000;
+  shdr.sh_offset = 0x6000;
+  shdr.sh_entsize = sizeof(Sym);
+  shdr.sh_size = shdr.sh_entsize * 10;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_PROGBITS;
+  shdr.sh_name = 0xa000;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  // The string data for the entries.
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_STRTAB;
+  shdr.sh_name = 0x20000;
+  shdr.sh_offset = 0xf000;
+  shdr.sh_size = 0x1000;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  InitSym<Sym>(0x5000, 0x90000, 0x1000, 0x100, 0xf000, "function_one");
+  InitSym<Sym>(0x6000, 0xd0000, 0x1000, 0x300, 0xf000, "function_two");
+
+  ASSERT_TRUE(elf->Init());
+  EXPECT_EQ(0U, elf->debug_frame_offset());
+  EXPECT_EQ(0U, elf->debug_frame_size());
+  EXPECT_EQ(0U, elf->gnu_debugdata_offset());
+  EXPECT_EQ(0U, elf->gnu_debugdata_size());
+
+  // Look in the first symbol table.
+  std::string name;
+  uint64_t name_offset;
+  ASSERT_TRUE(elf->GetFunctionName(0x90010, &name, &name_offset));
+  EXPECT_EQ("function_one", name);
+  EXPECT_EQ(16U, name_offset);
+  ASSERT_TRUE(elf->GetFunctionName(0xd0020, &name, &name_offset));
+  EXPECT_EQ("function_two", name);
+  EXPECT_EQ(32U, name_offset);
+}
+
+TEST_F(ElfInterfaceTest, init_section_headers32) {
+  InitSectionHeaders<Elf32_Ehdr, Elf32_Shdr, Elf32_Sym, ElfInterface32>(sizeof(Elf32_Shdr));
+}
+
+TEST_F(ElfInterfaceTest, init_section_headers64) {
+  InitSectionHeaders<Elf64_Ehdr, Elf64_Shdr, Elf64_Sym, ElfInterface64>(sizeof(Elf64_Shdr));
+}
+
+TEST_F(ElfInterfaceTest, init_section_headers_non_std_entry_size32) {
+  InitSectionHeaders<Elf32_Ehdr, Elf32_Shdr, Elf32_Sym, ElfInterface32>(0x100);
+}
+
+TEST_F(ElfInterfaceTest, init_section_headers_non_std_entry_size64) {
+  InitSectionHeaders<Elf64_Ehdr, Elf64_Shdr, Elf64_Sym, ElfInterface64>(0x100);
+}
+
+template <typename Ehdr, typename Shdr, typename ElfInterfaceType>
+void ElfInterfaceTest::InitSectionHeadersOffsets() {
+  std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));
+
+  uint64_t offset = 0x2000;
+
+  Ehdr ehdr;
+  memset(&ehdr, 0, sizeof(ehdr));
+  ehdr.e_shoff = offset;
+  ehdr.e_shnum = 10;
+  ehdr.e_shentsize = sizeof(Shdr);
+  ehdr.e_shstrndx = 2;
+  memory_.SetMemory(0, &ehdr, sizeof(ehdr));
+
+  offset += ehdr.e_shentsize;
+
+  Shdr shdr;
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_PROGBITS;
+  shdr.sh_link = 2;
+  shdr.sh_name = 0x200;
+  shdr.sh_addr = 0x5000;
+  shdr.sh_offset = 0x5000;
+  shdr.sh_entsize = 0x100;
+  shdr.sh_size = 0x800;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  // The string data for section header names.
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_STRTAB;
+  shdr.sh_name = 0x20000;
+  shdr.sh_offset = 0xf000;
+  shdr.sh_size = 0x1000;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_PROGBITS;
+  shdr.sh_link = 2;
+  shdr.sh_name = 0x100;
+  shdr.sh_addr = 0x6000;
+  shdr.sh_offset = 0x6000;
+  shdr.sh_entsize = 0x100;
+  shdr.sh_size = 0x500;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  memory_.SetMemory(0xf100, ".debug_frame", sizeof(".debug_frame"));
+  memory_.SetMemory(0xf200, ".gnu_debugdata", sizeof(".gnu_debugdata"));
+
+  ASSERT_TRUE(elf->Init());
+  EXPECT_EQ(0x6000U, elf->debug_frame_offset());
+  EXPECT_EQ(0x500U, elf->debug_frame_size());
+  EXPECT_EQ(0x5000U, elf->gnu_debugdata_offset());
+  EXPECT_EQ(0x800U, elf->gnu_debugdata_size());
+}
+
+TEST_F(ElfInterfaceTest, init_section_headers_offsets32) {
+  InitSectionHeadersOffsets<Elf32_Ehdr, Elf32_Shdr, ElfInterface32>();
+}
+
+TEST_F(ElfInterfaceTest, init_section_headers_offsets64) {
+  InitSectionHeadersOffsets<Elf64_Ehdr, Elf64_Shdr, ElfInterface64>();
+}