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Commit d58265e7 authored by Christopher Ferris's avatar Christopher Ferris Committed by android-build-merger
Browse files

Merge "Implement maps parsing."

am: 33e6b18d

Change-Id: I1673e501a90c559bc491c929e21bca6f6cec3a22
parents 6f183436 33e6b18d
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+2 −0
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@@ -54,6 +54,7 @@ cc_defaults {
        "ElfInterfaceArm.cpp",
        "ElfInterfaceArm.cpp",
        "Log.cpp",
        "Log.cpp",
        "Regs.cpp",
        "Regs.cpp",
        "Maps.cpp",
        "Memory.cpp",
        "Memory.cpp",
        "Symbols.cpp",
        "Symbols.cpp",
    ],
    ],
@@ -97,6 +98,7 @@ cc_defaults {
        "tests/ElfInterfaceTest.cpp",
        "tests/ElfInterfaceTest.cpp",
        "tests/ElfTest.cpp",
        "tests/ElfTest.cpp",
        "tests/LogFake.cpp",
        "tests/LogFake.cpp",
        "tests/MapsTest.cpp",
        "tests/MemoryFake.cpp",
        "tests/MemoryFake.cpp",
        "tests/MemoryFileTest.cpp",
        "tests/MemoryFileTest.cpp",
        "tests/MemoryLocalTest.cpp",
        "tests/MemoryLocalTest.cpp",
+196 −0
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/*
 * 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 <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <unistd.h>

#include <android-base/unique_fd.h>

#include <memory>
#include <string>
#include <vector>

#include "Maps.h"

MapInfo* Maps::Find(uint64_t pc) {
  if (maps_.empty()) {
    return nullptr;
  }
  size_t first = 0;
  size_t last = maps_.size();
  while (first < last) {
    size_t index = (first + last) / 2;
    MapInfo* cur = &maps_[index];
    if (pc >= cur->start && pc < cur->end) {
      return cur;
    } else if (pc < cur->start) {
      last = index;
    } else {
      first = index + 1;
    }
  }
  return nullptr;
}

bool Maps::ParseLine(const char* line, MapInfo* map_info) {
  char permissions[5];
  int name_pos;
  // Linux /proc/<pid>/maps lines:
  // 6f000000-6f01e000 rwxp 00000000 00:0c 16389419   /system/lib/libcomposer.so
  if (sscanf(line, "%" SCNx64 "-%" SCNx64 " %4s %" SCNx64 " %*x:%*x %*d %n", &map_info->start,
             &map_info->end, permissions, &map_info->offset, &name_pos) != 4) {
    return false;
  }
  map_info->flags = PROT_NONE;
  if (permissions[0] == 'r') {
    map_info->flags |= PROT_READ;
  }
  if (permissions[1] == 'w') {
    map_info->flags |= PROT_WRITE;
  }
  if (permissions[2] == 'x') {
    map_info->flags |= PROT_EXEC;
  }

  map_info->name = &line[name_pos];
  size_t length = map_info->name.length() - 1;
  if (map_info->name[length] == '\n') {
    map_info->name.erase(length);
  }
  // Mark a device map in /dev/and not in /dev/ashmem/ specially.
  if (!map_info->name.empty() && map_info->name.substr(0, 5) == "/dev/" &&
      map_info->name.substr(5, 7) != "ashmem/") {
    map_info->flags |= MAPS_FLAGS_DEVICE_MAP;
  }

  return true;
}

bool Maps::Parse() {
  std::unique_ptr<FILE, decltype(&fclose)> fp(fopen(GetMapsFile().c_str(), "re"), fclose);
  if (!fp) {
    return false;
  }

  bool valid = true;
  char* line = nullptr;
  size_t line_len;
  while (getline(&line, &line_len, fp.get()) > 0) {
    MapInfo map_info;
    if (!ParseLine(line, &map_info)) {
      valid = false;
      break;
    }

    maps_.push_back(map_info);
  }
  free(line);

  return valid;
}

Maps::~Maps() {
  for (auto& map : maps_) {
    delete map.elf;
    map.elf = nullptr;
  }
}

bool BufferMaps::Parse() {
  const char* start_of_line = buffer_;
  do {
    std::string line;
    const char* end_of_line = strchr(start_of_line, '\n');
    if (end_of_line == nullptr) {
      line = start_of_line;
    } else {
      end_of_line++;
      line = std::string(start_of_line, end_of_line - start_of_line);
    }

    MapInfo map_info;
    if (!ParseLine(line.c_str(), &map_info)) {
      return false;
    }
    maps_.push_back(map_info);

    start_of_line = end_of_line;
  } while (start_of_line != nullptr && *start_of_line != '\0');
  return true;
}

const std::string RemoteMaps::GetMapsFile() const {
  return "/proc/" + std::to_string(pid_) + "/maps";
}

bool OfflineMaps::Parse() {
  // Format of maps information:
  //   <uint64_t> StartOffset
  //   <uint64_t> EndOffset
  //   <uint64_t> offset
  //   <uint16_t> flags
  //   <uint16_t> MapNameLength
  //   <VariableLengthValue> MapName
  android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(file_.c_str(), O_RDONLY)));
  if (fd == -1) {
    return false;
  }

  std::vector<char> name;
  while (true) {
    MapInfo map_info;
    ssize_t bytes = TEMP_FAILURE_RETRY(read(fd, &map_info.start, sizeof(map_info.start)));
    if (bytes == 0) {
      break;
    }
    if (bytes == -1 || bytes != sizeof(map_info.start)) {
      return false;
    }
    bytes = TEMP_FAILURE_RETRY(read(fd, &map_info.end, sizeof(map_info.end)));
    if (bytes == -1 || bytes != sizeof(map_info.end)) {
      return false;
    }
    bytes = TEMP_FAILURE_RETRY(read(fd, &map_info.offset, sizeof(map_info.offset)));
    if (bytes == -1 || bytes != sizeof(map_info.offset)) {
      return false;
    }
    bytes = TEMP_FAILURE_RETRY(read(fd, &map_info.flags, sizeof(map_info.flags)));
    if (bytes == -1 || bytes != sizeof(map_info.flags)) {
      return false;
    }
    uint16_t len;
    bytes = TEMP_FAILURE_RETRY(read(fd, &len, sizeof(len)));
    if (bytes == -1 || bytes != sizeof(len)) {
      return false;
    }
    if (len > 0) {
      name.resize(len);
      bytes = TEMP_FAILURE_RETRY(read(fd, name.data(), len));
      if (bytes == -1 || bytes != len) {
        return false;
      }
      map_info.name = std::string(name.data(), len);
    }
    maps_.push_back(map_info);
  }
  return true;
}

libunwindstack/Maps.h

0 → 100644
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/*
 * 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.
 */

#ifndef _LIBUNWINDSTACK_MAPS_H
#define _LIBUNWINDSTACK_MAPS_H

#include <sys/types.h>
#include <unistd.h>

#include <string>
#include <vector>

#include "Elf.h"
#include "MapInfo.h"

// Special flag to indicate a map is in /dev/. However, a map in
// /dev/ashmem/... does not set this flag.
static constexpr int MAPS_FLAGS_DEVICE_MAP = 0x8000;

class Maps {
 public:
  Maps() = default;
  virtual ~Maps();

  MapInfo* Find(uint64_t pc);

  bool ParseLine(const char* line, MapInfo* map_info);

  virtual bool Parse();

  virtual const std::string GetMapsFile() const { return ""; }

  typedef std::vector<MapInfo>::iterator iterator;
  iterator begin() { return maps_.begin(); }
  iterator end() { return maps_.end(); }

  typedef std::vector<MapInfo>::const_iterator const_iterator;
  const_iterator begin() const { return maps_.begin(); }
  const_iterator end() const { return maps_.end(); }

  size_t Total() { return maps_.size(); }

 protected:
  std::vector<MapInfo> maps_;
};

class RemoteMaps : public Maps {
 public:
  RemoteMaps(pid_t pid) : pid_(pid) {}
  virtual ~RemoteMaps() = default;

  virtual const std::string GetMapsFile() const override;

 private:
  pid_t pid_;
};

class LocalMaps : public RemoteMaps {
 public:
  LocalMaps() : RemoteMaps(getpid()) {}
  virtual ~LocalMaps() = default;
};

class BufferMaps : public Maps {
 public:
  BufferMaps(const char* buffer) : buffer_(buffer) {}
  virtual ~BufferMaps() = default;

  bool Parse() override;

 private:
  const char* buffer_;
};

class FileMaps : public Maps {
 public:
  FileMaps(const std::string& file) : file_(file) {}
  virtual ~FileMaps() = default;

  const std::string GetMapsFile() const override { return file_; }

 protected:
  const std::string file_;
};

class OfflineMaps : public FileMaps {
 public:
  OfflineMaps(const std::string& file) : FileMaps(file) {}
  virtual ~OfflineMaps() = default;

  bool Parse() override;
};

#endif  // _LIBUNWINDSTACK_MAPS_H
+237 −0
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/*
 * 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 <sys/mman.h>

#include <android-base/file.h>
#include <android-base/test_utils.h>
#include <gtest/gtest.h>

#include "Maps.h"

TEST(MapsTest, parse_permissions) {
  BufferMaps maps(
      "1000-2000 ---- 00000000 00:00 0\n"
      "2000-3000 r--- 00000000 00:00 0\n"
      "3000-4000 -w-- 00000000 00:00 0\n"
      "4000-5000 --x- 00000000 00:00 0\n"
      "5000-6000 rwx- 00000000 00:00 0\n");

  ASSERT_TRUE(maps.Parse());
  ASSERT_EQ(5U, maps.Total());
  auto it = maps.begin();
  ASSERT_EQ(PROT_NONE, it->flags);
  ASSERT_EQ(0x1000U, it->start);
  ASSERT_EQ(0x2000U, it->end);
  ASSERT_EQ(0U, it->offset);
  ASSERT_EQ("", it->name);
  ++it;
  ASSERT_EQ(PROT_READ, it->flags);
  ASSERT_EQ(0x2000U, it->start);
  ASSERT_EQ(0x3000U, it->end);
  ASSERT_EQ(0U, it->offset);
  ASSERT_EQ("", it->name);
  ++it;
  ASSERT_EQ(PROT_WRITE, it->flags);
  ASSERT_EQ(0x3000U, it->start);
  ASSERT_EQ(0x4000U, it->end);
  ASSERT_EQ(0U, it->offset);
  ASSERT_EQ("", it->name);
  ++it;
  ASSERT_EQ(PROT_EXEC, it->flags);
  ASSERT_EQ(0x4000U, it->start);
  ASSERT_EQ(0x5000U, it->end);
  ASSERT_EQ(0U, it->offset);
  ASSERT_EQ("", it->name);
  ++it;
  ASSERT_EQ(PROT_READ | PROT_WRITE | PROT_EXEC, it->flags);
  ASSERT_EQ(0x5000U, it->start);
  ASSERT_EQ(0x6000U, it->end);
  ASSERT_EQ(0U, it->offset);
  ASSERT_EQ("", it->name);
  ++it;
  ASSERT_EQ(it, maps.end());
}

TEST(MapsTest, parse_name) {
  BufferMaps maps(
      "720b29b000-720b29e000 rw-p 00000000 00:00 0\n"
      "720b29e000-720b29f000 rw-p 00000000 00:00 0 /system/lib/fake.so\n"
      "720b29f000-720b2a0000 rw-p 00000000 00:00 0");

  ASSERT_TRUE(maps.Parse());
  ASSERT_EQ(3U, maps.Total());
  auto it = maps.begin();
  ASSERT_EQ("", it->name);
  ASSERT_EQ(0x720b29b000U, it->start);
  ASSERT_EQ(0x720b29e000U, it->end);
  ASSERT_EQ(0U, it->offset);
  ASSERT_EQ(PROT_READ | PROT_WRITE, it->flags);
  ++it;
  ASSERT_EQ("/system/lib/fake.so", it->name);
  ASSERT_EQ(0x720b29e000U, it->start);
  ASSERT_EQ(0x720b29f000U, it->end);
  ASSERT_EQ(0U, it->offset);
  ASSERT_EQ(PROT_READ | PROT_WRITE, it->flags);
  ++it;
  ASSERT_EQ("", it->name);
  ASSERT_EQ(0x720b29f000U, it->start);
  ASSERT_EQ(0x720b2a0000U, it->end);
  ASSERT_EQ(0U, it->offset);
  ASSERT_EQ(PROT_READ | PROT_WRITE, it->flags);
  ++it;
  ASSERT_EQ(it, maps.end());
}

TEST(MapsTest, parse_offset) {
  BufferMaps maps(
      "a000-e000 rw-p 00000000 00:00 0 /system/lib/fake.so\n"
      "e000-f000 rw-p 00a12345 00:00 0 /system/lib/fake.so\n");

  ASSERT_TRUE(maps.Parse());
  ASSERT_EQ(2U, maps.Total());
  auto it = maps.begin();
  ASSERT_EQ(0U, it->offset);
  ASSERT_EQ(0xa000U, it->start);
  ASSERT_EQ(0xe000U, it->end);
  ASSERT_EQ(PROT_READ | PROT_WRITE, it->flags);
  ASSERT_EQ("/system/lib/fake.so", it->name);
  ++it;
  ASSERT_EQ(0xa12345U, it->offset);
  ASSERT_EQ(0xe000U, it->start);
  ASSERT_EQ(0xf000U, it->end);
  ASSERT_EQ(PROT_READ | PROT_WRITE, it->flags);
  ASSERT_EQ("/system/lib/fake.so", it->name);
  ++it;
  ASSERT_EQ(maps.end(), it);
}

TEST(MapsTest, device) {
  BufferMaps maps(
      "a000-e000 rw-p 00000000 00:00 0 /dev/\n"
      "f000-f100 rw-p 00000000 00:00 0 /dev/does_not_exist\n"
      "f100-f200 rw-p 00000000 00:00 0 /dev/ashmem/does_not_exist\n"
      "f200-f300 rw-p 00000000 00:00 0 /devsomething/does_not_exist\n");

  ASSERT_TRUE(maps.Parse());
  ASSERT_EQ(4U, maps.Total());
  auto it = maps.begin();
  ASSERT_TRUE(it->flags & 0x8000);
  ASSERT_EQ("/dev/", it->name);
  ++it;
  ASSERT_TRUE(it->flags & 0x8000);
  ASSERT_EQ("/dev/does_not_exist", it->name);
  ++it;
  ASSERT_FALSE(it->flags & 0x8000);
  ASSERT_EQ("/dev/ashmem/does_not_exist", it->name);
  ++it;
  ASSERT_FALSE(it->flags & 0x8000);
  ASSERT_EQ("/devsomething/does_not_exist", it->name);
}

TEST(MapsTest, file_smoke) {
  TemporaryFile tf;
  ASSERT_TRUE(tf.fd != -1);

  ASSERT_TRUE(
      android::base::WriteStringToFile("720b29b000-720b29e000 r-xp a0000000 00:00 0   /fake.so\n"
                                       "720b2b0000-720b2e0000 r-xp b0000000 00:00 0   /fake2.so\n"
                                       "720b2e0000-720b2f0000 r-xp c0000000 00:00 0   /fake3.so\n",
                                       tf.path, 0660, getuid(), getgid()));

  FileMaps maps(tf.path);

  ASSERT_TRUE(maps.Parse());
  ASSERT_EQ(3U, maps.Total());
  auto it = maps.begin();
  ASSERT_EQ(0x720b29b000U, it->start);
  ASSERT_EQ(0x720b29e000U, it->end);
  ASSERT_EQ(0xa0000000U, it->offset);
  ASSERT_EQ(PROT_READ | PROT_EXEC, it->flags);
  ASSERT_EQ("/fake.so", it->name);
  ++it;
  ASSERT_EQ(0x720b2b0000U, it->start);
  ASSERT_EQ(0x720b2e0000U, it->end);
  ASSERT_EQ(0xb0000000U, it->offset);
  ASSERT_EQ(PROT_READ | PROT_EXEC, it->flags);
  ASSERT_EQ("/fake2.so", it->name);
  ++it;
  ASSERT_EQ(0x720b2e0000U, it->start);
  ASSERT_EQ(0x720b2f0000U, it->end);
  ASSERT_EQ(0xc0000000U, it->offset);
  ASSERT_EQ(PROT_READ | PROT_EXEC, it->flags);
  ASSERT_EQ("/fake3.so", it->name);
  ++it;
  ASSERT_EQ(it, maps.end());
}

TEST(MapsTest, find) {
  BufferMaps maps(
      "1000-2000 r--p 00000010 00:00 0 /system/lib/fake1.so\n"
      "3000-4000 -w-p 00000020 00:00 0 /system/lib/fake2.so\n"
      "6000-8000 --xp 00000030 00:00 0 /system/lib/fake3.so\n"
      "a000-b000 rw-p 00000040 00:00 0 /system/lib/fake4.so\n"
      "e000-f000 rwxp 00000050 00:00 0 /system/lib/fake5.so\n");
  ASSERT_TRUE(maps.Parse());
  ASSERT_EQ(5U, maps.Total());

  ASSERT_TRUE(maps.Find(0x500) == nullptr);
  ASSERT_TRUE(maps.Find(0x2000) == nullptr);
  ASSERT_TRUE(maps.Find(0x5010) == nullptr);
  ASSERT_TRUE(maps.Find(0x9a00) == nullptr);
  ASSERT_TRUE(maps.Find(0xf000) == nullptr);
  ASSERT_TRUE(maps.Find(0xf010) == nullptr);

  MapInfo* info = maps.Find(0x1000);
  ASSERT_TRUE(info != nullptr);
  ASSERT_EQ(0x1000U, info->start);
  ASSERT_EQ(0x2000U, info->end);
  ASSERT_EQ(0x10U, info->offset);
  ASSERT_EQ(PROT_READ, info->flags);
  ASSERT_EQ("/system/lib/fake1.so", info->name);

  info = maps.Find(0x3020);
  ASSERT_TRUE(info != nullptr);
  ASSERT_EQ(0x3000U, info->start);
  ASSERT_EQ(0x4000U, info->end);
  ASSERT_EQ(0x20U, info->offset);
  ASSERT_EQ(PROT_WRITE, info->flags);
  ASSERT_EQ("/system/lib/fake2.so", info->name);

  info = maps.Find(0x6020);
  ASSERT_TRUE(info != nullptr);
  ASSERT_EQ(0x6000U, info->start);
  ASSERT_EQ(0x8000U, info->end);
  ASSERT_EQ(0x30U, info->offset);
  ASSERT_EQ(PROT_EXEC, info->flags);
  ASSERT_EQ("/system/lib/fake3.so", info->name);

  info = maps.Find(0xafff);
  ASSERT_TRUE(info != nullptr);
  ASSERT_EQ(0xa000U, info->start);
  ASSERT_EQ(0xb000U, info->end);
  ASSERT_EQ(0x40U, info->offset);
  ASSERT_EQ(PROT_READ | PROT_WRITE, info->flags);
  ASSERT_EQ("/system/lib/fake4.so", info->name);

  info = maps.Find(0xe500);
  ASSERT_TRUE(info != nullptr);
  ASSERT_EQ(0xe000U, info->start);
  ASSERT_EQ(0xf000U, info->end);
  ASSERT_EQ(0x50U, info->offset);
  ASSERT_EQ(PROT_READ | PROT_WRITE | PROT_EXEC, info->flags);
  ASSERT_EQ("/system/lib/fake5.so", info->name);
}