android_system_core/libunwindstack/tests/DwarfSectionTest.cpp
Tamas Petz 6835d019b2 libunwindstack: support for Armv8.3-A Pointer Authentication
This patch adds support for handling return addresses signed with
pointer authentication. It simply strips the authentication code
without verifying its correctness, and thus works with both A and B
keys and through key-change boundaries.

Additons:
  * DW_CFA_AARCH64_negate_ra_state: new CFA operation.
  * RA_SIGN_STATE: new pseudo register.
  * Pass the arch to DwarfCfa so that the new op is only executed
    on aarch64.

The stripping uses the xpaclri instruction. This is a hint space
instruction which is compatible with pre Armv8.3-A devices. For cases
where it cannot be used, a mask can be set instead.

Test: libunwindstack_test
      Without this patch all UnwindTest.* testcases should fail if
      compiled with Pointer Authentication.

The tests should be executed with both -mbranch-protection=pac-ret and
pac-ret+leaf flags so that either some or all functions have pointer
authentication instructions.

Change-Id: Id7c3f1d0e2fc7fccb19bd1430826264405a9df7c
2020-07-14 13:31:59 -07:00

174 lines
5.5 KiB
C++

/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdint.h>
#include <gmock/gmock.h>
#include <gtest/gtest.h>
#include <unwindstack/DwarfSection.h>
#include <unwindstack/Elf.h>
#include "MemoryFake.h"
#include "RegsFake.h"
namespace unwindstack {
class MockDwarfSection : public DwarfSection {
public:
MockDwarfSection(Memory* memory) : DwarfSection(memory) {}
virtual ~MockDwarfSection() = default;
MOCK_METHOD(bool, Init, (uint64_t, uint64_t, int64_t), (override));
MOCK_METHOD(bool, Eval, (const DwarfCie*, Memory*, const dwarf_loc_regs_t&, Regs*, bool*),
(override));
MOCK_METHOD(bool, Log, (uint8_t, uint64_t, const DwarfFde*, ArchEnum arch), (override));
MOCK_METHOD(void, GetFdes, (std::vector<const DwarfFde*>*), (override));
MOCK_METHOD(const DwarfFde*, GetFdeFromPc, (uint64_t), (override));
MOCK_METHOD(bool, GetCfaLocationInfo,
(uint64_t, const DwarfFde*, dwarf_loc_regs_t*, ArchEnum arch), (override));
MOCK_METHOD(uint64_t, GetCieOffsetFromFde32, (uint32_t), (override));
MOCK_METHOD(uint64_t, GetCieOffsetFromFde64, (uint64_t), (override));
MOCK_METHOD(uint64_t, AdjustPcFromFde, (uint64_t), (override));
};
class DwarfSectionTest : public ::testing::Test {
protected:
void SetUp() override { section_.reset(new MockDwarfSection(&memory_)); }
MemoryFake memory_;
std::unique_ptr<MockDwarfSection> section_;
static RegsFake regs_;
};
RegsFake DwarfSectionTest::regs_(10);
TEST_F(DwarfSectionTest, Step_fail_fde) {
EXPECT_CALL(*section_, GetFdeFromPc(0x1000)).WillOnce(::testing::Return(nullptr));
bool finished;
ASSERT_FALSE(section_->Step(0x1000, nullptr, nullptr, &finished));
}
TEST_F(DwarfSectionTest, Step_fail_cie_null) {
DwarfFde fde{};
fde.pc_end = 0x2000;
fde.cie = nullptr;
EXPECT_CALL(*section_, GetFdeFromPc(0x1000)).WillOnce(::testing::Return(&fde));
bool finished;
ASSERT_FALSE(section_->Step(0x1000, &regs_, nullptr, &finished));
}
TEST_F(DwarfSectionTest, Step_fail_cfa_location) {
DwarfCie cie{};
DwarfFde fde{};
fde.pc_end = 0x2000;
fde.cie = &cie;
EXPECT_CALL(*section_, GetFdeFromPc(0x1000)).WillOnce(::testing::Return(&fde));
EXPECT_CALL(*section_, GetCfaLocationInfo(0x1000, &fde, ::testing::_, ::testing::_))
.WillOnce(::testing::Return(false));
bool finished;
ASSERT_FALSE(section_->Step(0x1000, &regs_, nullptr, &finished));
}
TEST_F(DwarfSectionTest, Step_pass) {
DwarfCie cie{};
DwarfFde fde{};
fde.pc_end = 0x2000;
fde.cie = &cie;
EXPECT_CALL(*section_, GetFdeFromPc(0x1000)).WillOnce(::testing::Return(&fde));
EXPECT_CALL(*section_, GetCfaLocationInfo(0x1000, &fde, ::testing::_, ::testing::_))
.WillOnce(::testing::Return(true));
MemoryFake process;
EXPECT_CALL(*section_, Eval(&cie, &process, ::testing::_, &regs_, ::testing::_))
.WillOnce(::testing::Return(true));
bool finished;
ASSERT_TRUE(section_->Step(0x1000, &regs_, &process, &finished));
}
static bool MockGetCfaLocationInfo(::testing::Unused, const DwarfFde* fde,
dwarf_loc_regs_t* loc_regs, ArchEnum) {
loc_regs->pc_start = fde->pc_start;
loc_regs->pc_end = fde->pc_end;
return true;
}
TEST_F(DwarfSectionTest, Step_cache) {
DwarfCie cie{};
DwarfFde fde{};
fde.pc_start = 0x500;
fde.pc_end = 0x2000;
fde.cie = &cie;
EXPECT_CALL(*section_, GetFdeFromPc(0x1000)).WillOnce(::testing::Return(&fde));
EXPECT_CALL(*section_, GetCfaLocationInfo(0x1000, &fde, ::testing::_, ::testing::_))
.WillOnce(::testing::Invoke(MockGetCfaLocationInfo));
MemoryFake process;
EXPECT_CALL(*section_, Eval(&cie, &process, ::testing::_, &regs_, ::testing::_))
.WillRepeatedly(::testing::Return(true));
bool finished;
ASSERT_TRUE(section_->Step(0x1000, &regs_, &process, &finished));
ASSERT_TRUE(section_->Step(0x1000, &regs_, &process, &finished));
ASSERT_TRUE(section_->Step(0x1500, &regs_, &process, &finished));
}
TEST_F(DwarfSectionTest, Step_cache_not_in_pc) {
DwarfCie cie{};
DwarfFde fde0{};
fde0.pc_start = 0x1000;
fde0.pc_end = 0x2000;
fde0.cie = &cie;
EXPECT_CALL(*section_, GetFdeFromPc(0x1000)).WillOnce(::testing::Return(&fde0));
EXPECT_CALL(*section_, GetCfaLocationInfo(0x1000, &fde0, ::testing::_, ::testing::_))
.WillOnce(::testing::Invoke(MockGetCfaLocationInfo));
MemoryFake process;
EXPECT_CALL(*section_, Eval(&cie, &process, ::testing::_, &regs_, ::testing::_))
.WillRepeatedly(::testing::Return(true));
bool finished;
ASSERT_TRUE(section_->Step(0x1000, &regs_, &process, &finished));
DwarfFde fde1{};
fde1.pc_start = 0x500;
fde1.pc_end = 0x800;
fde1.cie = &cie;
EXPECT_CALL(*section_, GetFdeFromPc(0x600)).WillOnce(::testing::Return(&fde1));
EXPECT_CALL(*section_, GetCfaLocationInfo(0x600, &fde1, ::testing::_, ::testing::_))
.WillOnce(::testing::Invoke(MockGetCfaLocationInfo));
ASSERT_TRUE(section_->Step(0x600, &regs_, &process, &finished));
ASSERT_TRUE(section_->Step(0x700, &regs_, &process, &finished));
}
} // namespace unwindstack