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Merge "Do not remove speculative frames in all cases."

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am: 0d7c0f78c4

Change-Id: Id4e5c240cb9c8d98f428a4a38764a65379d2dabb
This commit is contained in:
Christopher Ferris 2018-12-13 14:55:06 -08:00 • committed by android-build-merger
commit b99ec5454f
2 changed files with 71 additions and 3 deletions
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10
libunwindstack/Unwinder.cpp
View file

@ -239,8 +239,14 @@ void Unwinder::Unwind(const std::vector<std::string>* initial_map_names_to_skip,
if (!stepped) { if (!stepped) {
if (return_address_attempt) { if (return_address_attempt) {
// Remove the speculative frame. // Only remove the speculative frame if there are more than two frames
frames_.pop_back(); // or the pc in the first frame is in a valid map.
// This allows for a case where the code jumps into the middle of
// nowhere, but there is no other unwind information after that.
if (frames_.size() != 2 || maps_->Find(frames_[0].pc) != nullptr) {
// Remove the speculative frame.
frames_.pop_back();
}
break; break;
} else if (in_device_map) { } else if (in_device_map) {
// Do not attempt any other unwinding, pc or sp is in a device // Do not attempt any other unwinding, pc or sp is in a device

64
libunwindstack/tests/UnwinderTest.cpp
View file

@ -659,6 +659,54 @@ TEST_F(UnwinderTest, speculative_frame_removed) {
ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame0", 0)); ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame0", 0));
ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame1", 1)); ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame1", 1));
// Fake as if code called a nullptr function.
regs_.set_pc(0x20000);
regs_.set_sp(0x10000);
ElfInterfaceFake::FakePushStepData(StepData(0, 0x10010, false));
regs_.FakeSetReturnAddress(0x12);
regs_.FakeSetReturnAddressValid(true);
Unwinder unwinder(64, &maps_, &regs_, process_memory_);
unwinder.Unwind();
EXPECT_EQ(ERROR_INVALID_MAP, unwinder.LastErrorCode());
ASSERT_EQ(2U, unwinder.NumFrames());
auto* frame = &unwinder.frames()[0];
EXPECT_EQ(0U, frame->num);
EXPECT_EQ(0U, frame->rel_pc);
EXPECT_EQ(0x20000U, frame->pc);
EXPECT_EQ(0x10000U, frame->sp);
EXPECT_EQ("Frame0", frame->function_name);
EXPECT_EQ(0U, frame->function_offset);
EXPECT_EQ("/system/fake/libunwind.so", frame->map_name);
EXPECT_EQ(0U, frame->map_offset);
EXPECT_EQ(0x20000U, frame->map_start);
EXPECT_EQ(0x22000U, frame->map_end);
EXPECT_EQ(0U, frame->map_load_bias);
EXPECT_EQ(PROT_READ | PROT_WRITE, frame->map_flags);
frame = &unwinder.frames()[1];
EXPECT_EQ(1U, frame->num);
EXPECT_EQ(0U, frame->rel_pc);
EXPECT_EQ(0U, frame->pc);
EXPECT_EQ(0x10010U, frame->sp);
EXPECT_EQ("", frame->function_name);
EXPECT_EQ(0U, frame->function_offset);
EXPECT_EQ("", frame->map_name);
EXPECT_EQ(0U, frame->map_offset);
EXPECT_EQ(0U, frame->map_start);
EXPECT_EQ(0U, frame->map_end);
EXPECT_EQ(0U, frame->map_load_bias);
EXPECT_EQ(0, frame->map_flags);
}
// Verify that a speculative frame is added and left if there are only
// two frames and the pc is in the middle nowhere.
TEST_F(UnwinderTest, speculative_frame_not_removed_pc_bad) {
ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame0", 0));
ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame1", 1));
// Fake as if code called a nullptr function. // Fake as if code called a nullptr function.
regs_.set_pc(0); regs_.set_pc(0);
regs_.set_sp(0x10000); regs_.set_sp(0x10000);
@ -669,7 +717,7 @@ TEST_F(UnwinderTest, speculative_frame_removed) {
unwinder.Unwind(); unwinder.Unwind();
EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode()); EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
ASSERT_EQ(1U, unwinder.NumFrames()); ASSERT_EQ(2U, unwinder.NumFrames());
auto* frame = &unwinder.frames()[0]; auto* frame = &unwinder.frames()[0];
EXPECT_EQ(0U, frame->num); EXPECT_EQ(0U, frame->num);
@ -684,6 +732,20 @@ TEST_F(UnwinderTest, speculative_frame_removed) {
EXPECT_EQ(0U, frame->map_end); EXPECT_EQ(0U, frame->map_end);
EXPECT_EQ(0U, frame->map_load_bias); EXPECT_EQ(0U, frame->map_load_bias);
EXPECT_EQ(0, frame->map_flags); EXPECT_EQ(0, frame->map_flags);
frame = &unwinder.frames()[1];
EXPECT_EQ(1U, frame->num);
EXPECT_EQ(0x200U, frame->rel_pc);
EXPECT_EQ(0x1200U, frame->pc);
EXPECT_EQ(0x10000U, frame->sp);
EXPECT_EQ("Frame0", frame->function_name);
EXPECT_EQ(0U, frame->function_offset);
EXPECT_EQ("/system/fake/libc.so", frame->map_name);
EXPECT_EQ(0U, frame->map_offset);
EXPECT_EQ(0x1000U, frame->map_start);
EXPECT_EQ(0x8000U, frame->map_end);
EXPECT_EQ(0U, frame->map_load_bias);
EXPECT_EQ(PROT_READ | PROT_WRITE, frame->map_flags);
} }
// Verify that an unwind stops when a frame is in given suffix. // Verify that an unwind stops when a frame is in given suffix.