1 files changed, 71 insertions, 13 deletions

diff --git a/libunwindstack/tests/MapInfoCreateMemoryTest.cpp b/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
index 9e45e7812..2aab9c652 100644
--- a/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
+++ b/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
@@ -38,30 +38,50 @@ namespace unwindstack {
 
 class MapInfoCreateMemoryTest : public ::testing::Test {
  protected:
+  template <typename Ehdr, typename Shdr>
+  static void InitElf(int fd, uint64_t file_offset, uint64_t sh_offset, uint8_t class_type) {
+    std::vector<uint8_t> buffer(20000);
+    memset(buffer.data(), 0, buffer.size());
+
+    Ehdr ehdr;
+    memset(&ehdr, 0, sizeof(ehdr));
+    memcpy(ehdr.e_ident, ELFMAG, SELFMAG);
+    ehdr.e_ident[EI_CLASS] = class_type;
+    ehdr.e_shoff = sh_offset;
+    ehdr.e_shentsize = sizeof(Shdr) + 100;
+    ehdr.e_shnum = 4;
+    memcpy(&buffer[file_offset], &ehdr, sizeof(ehdr));
+
+    ASSERT_TRUE(android::base::WriteFully(fd, buffer.data(), buffer.size()));
+  }
+
   static void SetUpTestCase() {
     std::vector<uint8_t> buffer(1024);
+    memset(buffer.data(), 0, buffer.size());
     memcpy(buffer.data(), ELFMAG, SELFMAG);
-    for (size_t i = SELFMAG; i < buffer.size(); i++) {
-      buffer[i] = i / 256 + 1;
-    }
+    buffer[EI_CLASS] = ELFCLASS32;
     ASSERT_TRUE(android::base::WriteFully(elf_.fd, buffer.data(), buffer.size()));
 
-    for (size_t i = 0; i < 0x100; i++) {
-      buffer[i] = i / 256 + 1;
-    }
+    memset(buffer.data(), 0, buffer.size());
     memcpy(&buffer[0x100], ELFMAG, SELFMAG);
-    for (size_t i = 0x100 + SELFMAG; i < buffer.size(); i++) {
-      buffer[i] = i / 256 + 1;
-    }
+    buffer[0x100 + EI_CLASS] = ELFCLASS64;
     ASSERT_TRUE(android::base::WriteFully(elf_at_100_.fd, buffer.data(), buffer.size()));
+
+    InitElf<Elf32_Ehdr, Elf32_Shdr>(elf32_at_map_.fd, 0x1000, 0x2000, ELFCLASS32);
+    InitElf<Elf64_Ehdr, Elf64_Shdr>(elf64_at_map_.fd, 0x2000, 0x3000, ELFCLASS64);
   }
 
   static TemporaryFile elf_;
 
   static TemporaryFile elf_at_100_;
+
+  static TemporaryFile elf32_at_map_;
+  static TemporaryFile elf64_at_map_;
 };
 TemporaryFile MapInfoCreateMemoryTest::elf_;
 TemporaryFile MapInfoCreateMemoryTest::elf_at_100_;
+TemporaryFile MapInfoCreateMemoryTest::elf32_at_map_;
+TemporaryFile MapInfoCreateMemoryTest::elf64_at_map_;
 
 TEST_F(MapInfoCreateMemoryTest, end_le_start) {
   MapInfo info{.start = 0x100, .end = 0x100, .offset = 0, .name = elf_.path};
@@ -93,8 +113,9 @@ TEST_F(MapInfoCreateMemoryTest, file_backed_non_zero_offset_full_file) {
   std::vector<uint8_t> buffer(1024);
   ASSERT_TRUE(memory->Read(0, buffer.data(), 1024));
   ASSERT_TRUE(memcmp(buffer.data(), ELFMAG, SELFMAG) == 0);
-  for (size_t i = SELFMAG; i < buffer.size(); i++) {
-    ASSERT_EQ(i / 256 + 1, buffer[i]) << "Failed at byte " << i;
+  ASSERT_EQ(ELFCLASS32, buffer[EI_CLASS]);
+  for (size_t i = EI_CLASS + 1; i < buffer.size(); i++) {
+    ASSERT_EQ(0, buffer[i]) << "Failed at byte " << i;
   }
 
   ASSERT_FALSE(memory->Read(1024, buffer.data(), 1));
@@ -113,13 +134,50 @@ TEST_F(MapInfoCreateMemoryTest, file_backed_non_zero_offset_partial_file) {
   std::vector<uint8_t> buffer(0x100);
   ASSERT_TRUE(memory->Read(0, buffer.data(), 0x100));
   ASSERT_TRUE(memcmp(buffer.data(), ELFMAG, SELFMAG) == 0);
-  for (size_t i = SELFMAG; i < buffer.size(); i++) {
-    ASSERT_EQ(2, buffer[i]) << "Failed at byte " << i;
+  ASSERT_EQ(ELFCLASS64, buffer[EI_CLASS]);
+  for (size_t i = EI_CLASS + 1; i < buffer.size(); i++) {
+    ASSERT_EQ(0, buffer[i]) << "Failed at byte " << i;
   }
 
   ASSERT_FALSE(memory->Read(0x100, buffer.data(), 1));
 }
 
+// Verify that if the offset is non-zero and there is an elf at that
+// offset, that only part of the file is used. Further verify that if the
+// embedded elf is bigger than the initial map, the new object is larger
+// than the original map size. Do this for a 32 bit elf and a 64 bit elf.
+TEST_F(MapInfoCreateMemoryTest, file_backed_non_zero_offset_partial_file_whole_elf32) {
+  MapInfo info{.start = 0x5000, .end = 0x6000, .offset = 0x1000, .name = elf32_at_map_.path};
+
+  std::unique_ptr<Memory> memory(info.CreateMemory(getpid()));
+  ASSERT_TRUE(memory.get() != nullptr);
+  ASSERT_EQ(0U, info.elf_offset);
+
+  // Verify the memory is a valid elf.
+  uint8_t e_ident[SELFMAG + 1];
+  ASSERT_TRUE(memory->Read(0, e_ident, SELFMAG));
+  ASSERT_EQ(0, memcmp(e_ident, ELFMAG, SELFMAG));
+
+  // Read past the end of what would normally be the size of the map.
+  ASSERT_TRUE(memory->Read(0x1000, e_ident, 1));
+}
+
+TEST_F(MapInfoCreateMemoryTest, file_backed_non_zero_offset_partial_file_whole_elf64) {
+  MapInfo info{.start = 0x7000, .end = 0x8000, .offset = 0x2000, .name = elf64_at_map_.path};
+
+  std::unique_ptr<Memory> memory(info.CreateMemory(getpid()));
+  ASSERT_TRUE(memory.get() != nullptr);
+  ASSERT_EQ(0U, info.elf_offset);
+
+  // Verify the memory is a valid elf.
+  uint8_t e_ident[SELFMAG + 1];
+  ASSERT_TRUE(memory->Read(0, e_ident, SELFMAG));
+  ASSERT_EQ(0, memcmp(e_ident, ELFMAG, SELFMAG));
+
+  // Read past the end of what would normally be the size of the map.
+  ASSERT_TRUE(memory->Read(0x1000, e_ident, 1));
+}
+
 // Verify that device file names will never result in Memory object creation.
 TEST_F(MapInfoCreateMemoryTest, check_device_maps) {
   // Set up some memory so that a valid local memory object would