tequilaOS/platform_system_core
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Fix computation of pc.

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Fix the case where a non-zero load bias or a non-zero elf offset causes
the pc to be set incorrectly.

Add unit tests for these cases.

Bug: 73172903

Test: Ran unit tests.
Test: Ran the unit tests from the simpleperf CL that detected the failure.
Change-Id: Id8802c00b34c66875edd4926a20c5fccd2bb7d72
This commit is contained in:
Christopher Ferris 2018-02-12 13:24:18 -08:00
parent 73a2508dc4
commit e4df5f5ab5
2 changed files with 73 additions and 1 deletions
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2
libunwindstack/Unwinder.cpp
View file

@ -91,7 +91,7 @@ void Unwinder::FillInFrame(MapInfo* map_info, Elf* elf, uint64_t adjusted_rel_pc
return;
}
frame->pc = map_info->start + adjusted_rel_pc;
frame->pc = map_info->start + adjusted_rel_pc - elf->GetLoadBias() - map_info->elf_offset;
frame->map_name = map_info->name;
frame->map_offset = map_info->offset;
frame->map_start = map_info->start;

72
libunwindstack/tests/UnwinderTest.cpp
View file

@ -102,6 +102,22 @@ class UnwinderTest : public ::testing::Test {
info->load_bias = 0;
maps_.FakeAddMapInfo(info);
info = new MapInfo(0xa5000, 0xa6000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
"/fake/fake_load_bias.so");
elf = new ElfFake(new MemoryFake);
info->elf.reset(elf);
elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
elf->FakeSetLoadBias(0x5000);
maps_.FakeAddMapInfo(info);
info = new MapInfo(0xa7000, 0xa8000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
"/fake/fake_offset.oat");
elf = new ElfFake(new MemoryFake);
info->elf.reset(elf);
elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
info->elf_offset = 0x8000;
maps_.FakeAddMapInfo(info);
process_memory_.reset(new MemoryFake);
}
@ -180,6 +196,62 @@ TEST_F(UnwinderTest, multiple_frames) {
EXPECT_EQ(PROT_READ | PROT_WRITE, frame->map_flags);
}
TEST_F(UnwinderTest, non_zero_load_bias) {
ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame0", 0));
regs_.FakeSetPc(0xa5500);
regs_.FakeSetSp(0x10000);
ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
Unwinder unwinder(64, &maps_, &regs_, process_memory_);
unwinder.Unwind();
EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
ASSERT_EQ(1U, unwinder.NumFrames());
auto* frame = &unwinder.frames()[0];
EXPECT_EQ(0U, frame->num);
EXPECT_EQ(0x5500U, frame->rel_pc);
EXPECT_EQ(0xa5500U, frame->pc);
EXPECT_EQ(0x10000U, frame->sp);
EXPECT_EQ("Frame0", frame->function_name);
EXPECT_EQ(0U, frame->function_offset);
EXPECT_EQ("/fake/fake_load_bias.so", frame->map_name);
EXPECT_EQ(0U, frame->map_offset);
EXPECT_EQ(0xa5000U, frame->map_start);
EXPECT_EQ(0xa6000U, frame->map_end);
EXPECT_EQ(0x5000U, frame->map_load_bias);
EXPECT_EQ(PROT_READ | PROT_WRITE | PROT_EXEC, frame->map_flags);
}
TEST_F(UnwinderTest, non_zero_elf_offset) {
ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame0", 0));
regs_.FakeSetPc(0xa7500);
regs_.FakeSetSp(0x10000);
ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
Unwinder unwinder(64, &maps_, &regs_, process_memory_);
unwinder.Unwind();
EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
ASSERT_EQ(1U, unwinder.NumFrames());
auto* frame = &unwinder.frames()[0];
EXPECT_EQ(0U, frame->num);
EXPECT_EQ(0x8500U, frame->rel_pc);
EXPECT_EQ(0xa7500U, frame->pc);
EXPECT_EQ(0x10000U, frame->sp);
EXPECT_EQ("Frame0", frame->function_name);
EXPECT_EQ(0U, frame->function_offset);
EXPECT_EQ("/fake/fake_offset.oat", frame->map_name);
EXPECT_EQ(0U, frame->map_offset);
EXPECT_EQ(0xa7000U, frame->map_start);
EXPECT_EQ(0xa8000U, frame->map_end);
EXPECT_EQ(0U, frame->map_load_bias);
EXPECT_EQ(PROT_READ | PROT_WRITE | PROT_EXEC, frame->map_flags);
}
TEST_F(UnwinderTest, non_zero_map_offset) {
ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame0", 0));