Add overflow checks in Memory objects.

Also change one of the reads to be explicitly ReadField instead of an
overloaded Read function.

Bug: 23762183

Test: Passes new unit tests.
Change-Id: Id848f7b632f67df0c5b7318d9e588942cfd2099a

1 files changed, 13 insertions, 0 deletions

diff --git a/libunwindstack/tests/MemoryRemoteTest.cpp b/libunwindstack/tests/MemoryRemoteTest.cpp
index 7664c3e00..e48edf7e5 100644
--- a/libunwindstack/tests/MemoryRemoteTest.cpp
+++ b/libunwindstack/tests/MemoryRemoteTest.cpp
@@ -33,6 +33,8 @@
 
 #include "Memory.h"
 
+#include "MemoryFake.h"
+
 class MemoryRemoteTest : public ::testing::Test {
  protected:
   static uint64_t NanoTime() {
@@ -121,6 +123,9 @@ TEST_F(MemoryRemoteTest, read_fail) {
   ASSERT_TRUE(remote.Read(reinterpret_cast<uint64_t>(src) + pagesize - 1, dst.data(), 1));
   ASSERT_FALSE(remote.Read(reinterpret_cast<uint64_t>(src) + pagesize - 4, dst.data(), 8));
 
+  // Check overflow condition is caught properly.
+  ASSERT_FALSE(remote.Read(UINT64_MAX - 100, dst.data(), 200));
+
   ASSERT_EQ(0, munmap(src, pagesize));
 
   ASSERT_TRUE(Detach(pid));
@@ -128,6 +133,14 @@ TEST_F(MemoryRemoteTest, read_fail) {
   kill(pid, SIGKILL);
 }
 
+TEST_F(MemoryRemoteTest, read_overflow) {
+  MemoryFakeRemote remote;
+
+  // Check overflow condition is caught properly.
+  std::vector<uint8_t> dst(200);
+  ASSERT_FALSE(remote.Read(UINT64_MAX - 100, dst.data(), 200));
+}
+
 TEST_F(MemoryRemoteTest, read_illegal) {
   pid_t pid;
   if ((pid = fork()) == 0) {