libunwindstack/tests/ElfInterfaceArmTest.cpp

/*
 * 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 <elf.h>

#include <gtest/gtest.h>

#include <vector>

#include <unwindstack/MachineArm.h>
#include <unwindstack/RegsArm.h>

#include "ElfInterfaceArm.h"

#include "ElfFake.h"
#include "MemoryFake.h"

namespace unwindstack {

class ElfInterfaceArmTest : public ::testing::Test {
 protected:
  void SetUp() override {
    memory_.Clear();
    process_memory_.Clear();
  }

  MemoryFake memory_;
  MemoryFake process_memory_;
};

TEST_F(ElfInterfaceArmTest, GetPrel32Addr) {
  ElfInterfaceArmFake interface(&memory_);
  memory_.SetData32(0x1000, 0x230000);

  uint32_t value;
  ASSERT_TRUE(interface.GetPrel31Addr(0x1000, &value));
  ASSERT_EQ(0x231000U, value);

  memory_.SetData32(0x1000, 0x80001000);
  ASSERT_TRUE(interface.GetPrel31Addr(0x1000, &value));
  ASSERT_EQ(0x2000U, value);

  memory_.SetData32(0x1000, 0x70001000);
  ASSERT_TRUE(interface.GetPrel31Addr(0x1000, &value));
  ASSERT_EQ(0xf0002000U, value);
}

TEST_F(ElfInterfaceArmTest, FindEntry_start_zero) {
  ElfInterfaceArmFake interface(&memory_);
  interface.FakeSetStartOffset(0);
  interface.FakeSetTotalEntries(10);

  uint64_t entry_offset;
  ASSERT_FALSE(interface.FindEntry(0x1000, &entry_offset));
}

TEST_F(ElfInterfaceArmTest, FindEntry_no_entries) {
  ElfInterfaceArmFake interface(&memory_);
  interface.FakeSetStartOffset(0x100);
  interface.FakeSetTotalEntries(0);

  uint64_t entry_offset;
  ASSERT_FALSE(interface.FindEntry(0x1000, &entry_offset));
}

TEST_F(ElfInterfaceArmTest, FindEntry_no_valid_memory) {
  ElfInterfaceArmFake interface(&memory_);
  interface.FakeSetStartOffset(0x100);
  interface.FakeSetTotalEntries(2);

  uint64_t entry_offset;
  ASSERT_FALSE(interface.FindEntry(0x1000, &entry_offset));
}

TEST_F(ElfInterfaceArmTest, FindEntry_ip_before_first) {
  ElfInterfaceArmFake interface(&memory_);
  interface.FakeSetStartOffset(0x1000);
  interface.FakeSetTotalEntries(1);
  memory_.SetData32(0x1000, 0x6000);

  uint64_t entry_offset;
  ASSERT_FALSE(interface.FindEntry(0x1000, &entry_offset));
}

TEST_F(ElfInterfaceArmTest, FindEntry_single_entry_negative_value) {
  ElfInterfaceArmFake interface(&memory_);
  interface.FakeSetStartOffset(0x8000);
  interface.FakeSetTotalEntries(1);
  memory_.SetData32(0x8000, 0x7fffff00);

  uint64_t entry_offset;
  ASSERT_TRUE(interface.FindEntry(0x7ff0, &entry_offset));
  ASSERT_EQ(0x8000U, entry_offset);
}

TEST_F(ElfInterfaceArmTest, FindEntry_two_entries) {
  ElfInterfaceArmFake interface(&memory_);
  interface.FakeSetStartOffset(0x1000);
  interface.FakeSetTotalEntries(2);
  memory_.SetData32(0x1000, 0x6000);
  memory_.SetData32(0x1008, 0x7000);

  uint64_t entry_offset;
  ASSERT_TRUE(interface.FindEntry(0x7000, &entry_offset));
  ASSERT_EQ(0x1000U, entry_offset);
}

TEST_F(ElfInterfaceArmTest, FindEntry_last_check_single_entry) {
  ElfInterfaceArmFake interface(&memory_);
  interface.FakeSetStartOffset(0x1000);
  interface.FakeSetTotalEntries(1);
  memory_.SetData32(0x1000, 0x6000);

  uint64_t entry_offset;
  ASSERT_TRUE(interface.FindEntry(0x7000, &entry_offset));
  ASSERT_EQ(0x1000U, entry_offset);

  // To guarantee that we are using the cache on the second run,
  // set the memory to a different value.
  memory_.SetData32(0x1000, 0x8000);
  ASSERT_TRUE(interface.FindEntry(0x7004, &entry_offset));
  ASSERT_EQ(0x1000U, entry_offset);
}

TEST_F(ElfInterfaceArmTest, FindEntry_last_check_multiple_entries) {
  ElfInterfaceArmFake interface(&memory_);
  interface.FakeSetStartOffset(0x1000);
  interface.FakeSetTotalEntries(2);
  memory_.SetData32(0x1000, 0x6000);
  memory_.SetData32(0x1008, 0x8000);

  uint64_t entry_offset;
  ASSERT_TRUE(interface.FindEntry(0x9008, &entry_offset));
  ASSERT_EQ(0x1008U, entry_offset);

  // To guarantee that we are using the cache on the second run,
  // set the memory to a different value.
  memory_.SetData32(0x1000, 0x16000);
  memory_.SetData32(0x1008, 0x18000);
  ASSERT_TRUE(interface.FindEntry(0x9100, &entry_offset));
  ASSERT_EQ(0x1008U, entry_offset);
}

TEST_F(ElfInterfaceArmTest, FindEntry_multiple_entries_even) {
  ElfInterfaceArmFake interface(&memory_);
  interface.FakeSetStartOffset(0x1000);
  interface.FakeSetTotalEntries(4);
  memory_.SetData32(0x1000, 0x6000);
  memory_.SetData32(0x1008, 0x7000);
  memory_.SetData32(0x1010, 0x8000);
  memory_.SetData32(0x1018, 0x9000);

  uint64_t entry_offset;
  ASSERT_TRUE(interface.FindEntry(0x9100, &entry_offset));
  ASSERT_EQ(0x1010U, entry_offset);

  // To guarantee that we are using the cache on the second run,
  // set the memory to a different value.
  memory_.SetData32(0x1000, 0x16000);
  memory_.SetData32(0x1008, 0x17000);
  memory_.SetData32(0x1010, 0x18000);
  memory_.SetData32(0x1018, 0x19000);
  ASSERT_TRUE(interface.FindEntry(0x9100, &entry_offset));
  ASSERT_EQ(0x1010U, entry_offset);
}

TEST_F(ElfInterfaceArmTest, FindEntry_multiple_entries_odd) {
  ElfInterfaceArmFake interface(&memory_);
  interface.FakeSetStartOffset(0x1000);
  interface.FakeSetTotalEntries(5);
  memory_.SetData32(0x1000, 0x5000);
  memory_.SetData32(0x1008, 0x6000);
  memory_.SetData32(0x1010, 0x7000);
  memory_.SetData32(0x1018, 0x8000);
  memory_.SetData32(0x1020, 0x9000);

  uint64_t entry_offset;
  ASSERT_TRUE(interface.FindEntry(0x8100, &entry_offset));
  ASSERT_EQ(0x1010U, entry_offset);

  // To guarantee that we are using the cache on the second run,
  // set the memory to a different value.
  memory_.SetData32(0x1000, 0x15000);
  memory_.SetData32(0x1008, 0x16000);
  memory_.SetData32(0x1010, 0x17000);
  memory_.SetData32(0x1018, 0x18000);
  memory_.SetData32(0x1020, 0x19000);
  ASSERT_TRUE(interface.FindEntry(0x8100, &entry_offset));
  ASSERT_EQ(0x1010U, entry_offset);
}

TEST_F(ElfInterfaceArmTest, iterate) {
  ElfInterfaceArmFake interface(&memory_);
  interface.FakeSetStartOffset(0x1000);
  interface.FakeSetTotalEntries(5);
  memory_.SetData32(0x1000, 0x5000);
  memory_.SetData32(0x1008, 0x6000);
  memory_.SetData32(0x1010, 0x7000);
  memory_.SetData32(0x1018, 0x8000);
  memory_.SetData32(0x1020, 0x9000);

  std::vector<uint32_t> entries;
  for (auto addr : interface) {
    entries.push_back(addr);
  }
  ASSERT_EQ(5U, entries.size());
  ASSERT_EQ(0x6000U, entries[0]);
  ASSERT_EQ(0x7008U, entries[1]);
  ASSERT_EQ(0x8010U, entries[2]);
  ASSERT_EQ(0x9018U, entries[3]);
  ASSERT_EQ(0xa020U, entries[4]);

  // Make sure the iterate cached the entries.
  memory_.SetData32(0x1000, 0x11000);
  memory_.SetData32(0x1008, 0x12000);
  memory_.SetData32(0x1010, 0x13000);
  memory_.SetData32(0x1018, 0x14000);
  memory_.SetData32(0x1020, 0x15000);

  entries.clear();
  for (auto addr : interface) {
    entries.push_back(addr);
  }
  ASSERT_EQ(5U, entries.size());
  ASSERT_EQ(0x6000U, entries[0]);
  ASSERT_EQ(0x7008U, entries[1]);
  ASSERT_EQ(0x8010U, entries[2]);
  ASSERT_EQ(0x9018U, entries[3]);
  ASSERT_EQ(0xa020U, entries[4]);
}

TEST_F(ElfInterfaceArmTest, HandleType_not_arm_exidx) {
  ElfInterfaceArmFake interface(&memory_);

  ASSERT_FALSE(interface.HandleType(0x1000, PT_NULL, 0));
  ASSERT_FALSE(interface.HandleType(0x1000, PT_LOAD, 0));
  ASSERT_FALSE(interface.HandleType(0x1000, PT_DYNAMIC, 0));
  ASSERT_FALSE(interface.HandleType(0x1000, PT_INTERP, 0));
  ASSERT_FALSE(interface.HandleType(0x1000, PT_NOTE, 0));
  ASSERT_FALSE(interface.HandleType(0x1000, PT_SHLIB, 0));
  ASSERT_FALSE(interface.HandleType(0x1000, PT_PHDR, 0));
  ASSERT_FALSE(interface.HandleType(0x1000, PT_TLS, 0));
  ASSERT_FALSE(interface.HandleType(0x1000, PT_LOOS, 0));
  ASSERT_FALSE(interface.HandleType(0x1000, PT_HIOS, 0));
  ASSERT_FALSE(interface.HandleType(0x1000, PT_LOPROC, 0));
  ASSERT_FALSE(interface.HandleType(0x1000, PT_HIPROC, 0));
  ASSERT_FALSE(interface.HandleType(0x1000, PT_GNU_EH_FRAME, 0));
  ASSERT_FALSE(interface.HandleType(0x1000, PT_GNU_STACK, 0));
}

TEST_F(ElfInterfaceArmTest, HandleType_arm_exidx) {
  ElfInterfaceArmFake interface(&memory_);

  Elf32_Phdr phdr;
  interface.FakeSetStartOffset(0x1000);
  interface.FakeSetTotalEntries(100);
  phdr.p_vaddr = 0x2000;
  phdr.p_memsz = 0xa00;

  // Verify that if reads fail, we don't set the values but still get true.
  ASSERT_TRUE(interface.HandleType(0x1000, 0x70000001, 0));
  ASSERT_EQ(0x1000U, interface.start_offset());
  ASSERT_EQ(100U, interface.total_entries());

  // Verify that if the second read fails, we still don't set the values.
  memory_.SetData32(
      0x1000 + reinterpret_cast<uint64_t>(&phdr.p_vaddr) - reinterpret_cast<uint64_t>(&phdr),
      phdr.p_vaddr);
  ASSERT_TRUE(interface.HandleType(0x1000, 0x70000001, 0));
  ASSERT_EQ(0x1000U, interface.start_offset());
  ASSERT_EQ(100U, interface.total_entries());

  // Everything is correct and present.
  memory_.SetData32(
      0x1000 + reinterpret_cast<uint64_t>(&phdr.p_memsz) - reinterpret_cast<uint64_t>(&phdr),
      phdr.p_memsz);
  ASSERT_TRUE(interface.HandleType(0x1000, 0x70000001, 0));
  ASSERT_EQ(0x2000U, interface.start_offset());
  ASSERT_EQ(320U, interface.total_entries());

  // Non-zero load bias.
  ASSERT_TRUE(interface.HandleType(0x1000, 0x70000001, 0x1000));
  ASSERT_EQ(0x1000U, interface.start_offset());
  ASSERT_EQ(320U, interface.total_entries());
}

TEST_F(ElfInterfaceArmTest, StepExidx) {
  ElfInterfaceArmFake interface(&memory_);

  // FindEntry fails.
  bool finished;
  ASSERT_FALSE(interface.StepExidx(0x7000, nullptr, nullptr, &finished));
  EXPECT_EQ(ERROR_UNWIND_INFO, interface.LastErrorCode());

  // ExtractEntry should fail.
  interface.FakeSetStartOffset(0x1000);
  interface.FakeSetTotalEntries(2);
  memory_.SetData32(0x1000, 0x6000);
  memory_.SetData32(0x1008, 0x8000);

  RegsArm regs;
  regs[ARM_REG_SP] = 0x1000;
  regs[ARM_REG_LR] = 0x20000;
  regs.set_sp(regs[ARM_REG_SP]);
  regs.set_pc(0x1234);
  ASSERT_FALSE(interface.StepExidx(0x7000, &regs, &process_memory_, &finished));
  EXPECT_EQ(ERROR_MEMORY_INVALID, interface.LastErrorCode());
  EXPECT_EQ(0x1004U, interface.LastErrorAddress());

  // Eval should fail.
  memory_.SetData32(0x1004, 0x81000000);
  ASSERT_FALSE(interface.StepExidx(0x7000, &regs, &process_memory_, &finished));
  EXPECT_EQ(ERROR_UNWIND_INFO, interface.LastErrorCode());

  // Everything should pass.
  memory_.SetData32(0x1004, 0x80b0b0b0);
  ASSERT_TRUE(interface.StepExidx(0x7000, &regs, &process_memory_, &finished));
  EXPECT_EQ(ERROR_UNWIND_INFO, interface.LastErrorCode());
  ASSERT_FALSE(finished);
  ASSERT_EQ(0x1000U, regs.sp());
  ASSERT_EQ(0x1000U, regs[ARM_REG_SP]);
  ASSERT_EQ(0x20000U, regs.pc());
  ASSERT_EQ(0x20000U, regs[ARM_REG_PC]);

  // Load bias is non-zero.
  interface.set_load_bias(0x1000);
  ASSERT_TRUE(interface.StepExidx(0x8000, &regs, &process_memory_, &finished));
  EXPECT_EQ(ERROR_UNWIND_INFO, interface.LastErrorCode());

  // Pc too small.
  interface.set_load_bias(0x9000);
  ASSERT_FALSE(interface.StepExidx(0x8000, &regs, &process_memory_, &finished));
  EXPECT_EQ(ERROR_UNWIND_INFO, interface.LastErrorCode());
}

TEST_F(ElfInterfaceArmTest, StepExidx_pc_set) {
  ElfInterfaceArmFake interface(&memory_);

  interface.FakeSetStartOffset(0x1000);
  interface.FakeSetTotalEntries(2);
  memory_.SetData32(0x1000, 0x6000);
  memory_.SetData32(0x1004, 0x808800b0);
  memory_.SetData32(0x1008, 0x8000);
  process_memory_.SetData32(0x10000, 0x10);

  RegsArm regs;
  regs[ARM_REG_SP] = 0x10000;
  regs[ARM_REG_LR] = 0x20000;
  regs.set_sp(regs[ARM_REG_SP]);
  regs.set_pc(0x1234);

  // Everything should pass.
  bool finished;
  ASSERT_TRUE(interface.StepExidx(0x7000, &regs, &process_memory_, &finished));
  EXPECT_EQ(ERROR_NONE, interface.LastErrorCode());
  ASSERT_FALSE(finished);
  ASSERT_EQ(0x10004U, regs.sp());
  ASSERT_EQ(0x10004U, regs[ARM_REG_SP]);
  ASSERT_EQ(0x10U, regs.pc());
  ASSERT_EQ(0x10U, regs[ARM_REG_PC]);
}

TEST_F(ElfInterfaceArmTest, StepExidx_cant_unwind) {
  ElfInterfaceArmFake interface(&memory_);

  interface.FakeSetStartOffset(0x1000);
  interface.FakeSetTotalEntries(1);
  memory_.SetData32(0x1000, 0x6000);
  memory_.SetData32(0x1004, 1);

  RegsArm regs;
  regs[ARM_REG_SP] = 0x10000;
  regs[ARM_REG_LR] = 0x20000;
  regs.set_sp(regs[ARM_REG_SP]);
  regs.set_pc(0x1234);

  bool finished;
  ASSERT_TRUE(interface.StepExidx(0x7000, &regs, &process_memory_, &finished));
  EXPECT_EQ(ERROR_NONE, interface.LastErrorCode());
  ASSERT_TRUE(finished);
  ASSERT_EQ(0x10000U, regs.sp());
  ASSERT_EQ(0x10000U, regs[ARM_REG_SP]);
  ASSERT_EQ(0x1234U, regs.pc());
}

TEST_F(ElfInterfaceArmTest, StepExidx_refuse_unwind) {
  ElfInterfaceArmFake interface(&memory_);

  interface.FakeSetStartOffset(0x1000);
  interface.FakeSetTotalEntries(1);
  memory_.SetData32(0x1000, 0x6000);
  memory_.SetData32(0x1004, 0x808000b0);

  RegsArm regs;
  regs[ARM_REG_SP] = 0x10000;
  regs[ARM_REG_LR] = 0x20000;
  regs.set_sp(regs[ARM_REG_SP]);
  regs.set_pc(0x1234);

  bool finished;
  ASSERT_TRUE(interface.StepExidx(0x7000, &regs, &process_memory_, &finished));
  EXPECT_EQ(ERROR_NONE, interface.LastErrorCode());
  ASSERT_TRUE(finished);
  ASSERT_EQ(0x10000U, regs.sp());
  ASSERT_EQ(0x10000U, regs[ARM_REG_SP]);
  ASSERT_EQ(0x1234U, regs.pc());
}

TEST_F(ElfInterfaceArmTest, StepExidx_pc_zero) {
  ElfInterfaceArmFake interface(&memory_);

  interface.FakeSetStartOffset(0x1000);
  interface.FakeSetTotalEntries(1);
  memory_.SetData32(0x1000, 0x6000);
  // Set the pc using a pop r15 command.
  memory_.SetData32(0x1004, 0x808800b0);

  // pc value of zero.
  process_memory_.SetData32(0x10000, 0);

  RegsArm regs;
  regs[ARM_REG_SP] = 0x10000;
  regs[ARM_REG_LR] = 0x20000;
  regs.set_sp(regs[ARM_REG_SP]);
  regs.set_pc(0x1234);

  bool finished;
  ASSERT_TRUE(interface.StepExidx(0x7000, &regs, &process_memory_, &finished));
  EXPECT_EQ(ERROR_NONE, interface.LastErrorCode());
  ASSERT_TRUE(finished);
  ASSERT_EQ(0U, regs.pc());

  // Now set the pc from the lr register (pop r14).
  memory_.SetData32(0x1004, 0x808400b0);

  regs[ARM_REG_SP] = 0x10000;
  regs[ARM_REG_LR] = 0x20000;
  regs.set_sp(regs[ARM_REG_SP]);
  regs.set_pc(0x1234);

  ASSERT_TRUE(interface.StepExidx(0x7000, &regs, &process_memory_, &finished));
  EXPECT_EQ(ERROR_NONE, interface.LastErrorCode());
  ASSERT_TRUE(finished);
  ASSERT_EQ(0U, regs.pc());
}

}  // namespace unwindstack