Merge "Remove Memory::ReadField."

am: 5dce8ce747

Change-Id: Iac64c37d7430b2d890d3fa9ad3f47f72179815ec

7 files changed, 18 insertions, 150 deletions

diff --git a/libunwindstack/ElfInterface.cpp b/libunwindstack/ElfInterface.cpp
index 915cddb..2c00456 100644
--- a/libunwindstack/ElfInterface.cpp
+++ b/libunwindstack/ElfInterface.cpp
@@ -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;
     }
diff --git a/libunwindstack/ElfInterfaceArm.cpp b/libunwindstack/ElfInterfaceArm.cpp
index a3244e8..3dd5d54 100644
--- a/libunwindstack/ElfInterfaceArm.cpp
+++ b/libunwindstack/ElfInterfaceArm.cpp
@@ -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) {
diff --git a/libunwindstack/ElfInterfaceArm.h b/libunwindstack/ElfInterfaceArm.h
index 3bee9cf..4c3a0c3 100644
--- a/libunwindstack/ElfInterfaceArm.h
+++ b/libunwindstack/ElfInterfaceArm.h
@@ -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;
 
diff --git a/libunwindstack/include/unwindstack/ElfInterface.h b/libunwindstack/include/unwindstack/ElfInterface.h
index 0c588da..5c1210d 100644
--- a/libunwindstack/include/unwindstack/ElfInterface.h
+++ b/libunwindstack/include/unwindstack/ElfInterface.h
@@ -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);
diff --git a/libunwindstack/include/unwindstack/Memory.h b/libunwindstack/include/unwindstack/Memory.h
index c0c07f4..dee5e98 100644
--- a/libunwindstack/include/unwindstack/Memory.h
+++ b/libunwindstack/include/unwindstack/Memory.h
@@ -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));
   }
diff --git a/libunwindstack/tests/ElfInterfaceArmTest.cpp b/libunwindstack/tests/ElfInterfaceArmTest.cpp
index a8bb4aa..43c6a97 100644
--- a/libunwindstack/tests/ElfInterfaceArmTest.cpp
+++ b/libunwindstack/tests/ElfInterfaceArmTest.cpp
@@ -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) {
diff --git a/libunwindstack/tests/MemoryTest.cpp b/libunwindstack/tests/MemoryTest.cpp
index 4a9ed9f..3655984 100644
--- a/libunwindstack/tests/MemoryTest.cpp
+++ b/libunwindstack/tests/MemoryTest.cpp
@@ -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");