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Commit 5677803c authored by Peter Collingbourne's avatar Peter Collingbourne Committed by Gerrit Code Review
Browse files

Merge "Create a debugger_process_info data structure with the process info pointers."

parents b480dc4f f3d542fe

debuggerd/crash_dump.cpp

+14 −16
Original line number Diff line number Diff line
@@ -264,15 +264,13 @@ static void ReadCrashInfo(unique_fd& fd, siginfo_t* siginfo, 
    ssize_t expected_size = 0;

    switch (crash_info->header.version) {

      case 1:

        expected_size = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataV1);

        break;



      case 2:

        expected_size = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataV2);

      case 3:

        expected_size = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataStatic);

        break;



      case 3:

        expected_size = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataV3);

      case 4:

        expected_size = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataDynamic);

        break;



      default:
@@ -280,25 +278,25 @@ static void ReadCrashInfo(unique_fd& fd, siginfo_t* siginfo, 
        break;

    };



    if (rc != expected_size) {

    if (rc < expected_size) {

      LOG(FATAL) << "read " << rc << " bytes when reading target crash information, expected "

                 << expected_size;

    }

  }



  switch (crash_info->header.version) {

    case 3:

      process_info->gwp_asan_state = crash_info->data.v3.gwp_asan_state;

      process_info->gwp_asan_metadata = crash_info->data.v3.gwp_asan_metadata;

      FALLTHROUGH_INTENDED;

    case 2:

      process_info->fdsan_table_address = crash_info->data.v2.fdsan_table_address;

    case 4:

      process_info->fdsan_table_address = crash_info->data.d.fdsan_table_address;

      process_info->gwp_asan_state = crash_info->data.d.gwp_asan_state;

      process_info->gwp_asan_metadata = crash_info->data.d.gwp_asan_metadata;

      FALLTHROUGH_INTENDED;

    case 1:

      process_info->abort_msg_address = crash_info->data.v1.abort_msg_address;

      *siginfo = crash_info->data.v1.siginfo;

    case 2:

    case 3:

      process_info->abort_msg_address = crash_info->data.s.abort_msg_address;

      *siginfo = crash_info->data.s.siginfo;

      regs->reset(unwindstack::Regs::CreateFromUcontext(unwindstack::Regs::CurrentArch(),

                                                        &crash_info->data.v1.ucontext));

                                                        &crash_info->data.s.ucontext));

      break;



    default:

debuggerd/crasher/crasher.cpp

+4 −2
Original line number Diff line number Diff line
@@ -349,7 +349,7 @@ noinline int do_action(const char* arg) { 
int main(int argc, char** argv) {

#if defined(STATIC_CRASHER)

    debuggerd_callbacks_t callbacks = {

      .get_abort_message = []() {

      .get_process_info = []() {

        static struct {

          size_t size;

          char msg[32];
@@ -357,7 +357,9 @@ int main(int argc, char** argv) { 


        msg.size = strlen("dummy abort message");

        memcpy(msg.msg, "dummy abort message", strlen("dummy abort message"));

        return reinterpret_cast<abort_msg_t*>(&msg);

        return debugger_process_info{

            .abort_msg = reinterpret_cast<void*>(&msg),

        };

      },

      .post_dump = nullptr

    };

debuggerd/handler/debuggerd_handler.cpp

+30 −35
Original line number Diff line number Diff line
@@ -297,10 +297,7 @@ struct debugger_thread_info { 
  pid_t pseudothread_tid;

  siginfo_t* siginfo;

  void* ucontext;

  uintptr_t abort_msg;

  uintptr_t fdsan_table;

  uintptr_t gwp_asan_state;

  uintptr_t gwp_asan_metadata;

  debugger_process_info process_info;

};



// Logging and contacting debuggerd requires free file descriptors, which we might not have.
@@ -344,25 +341,36 @@ static int debuggerd_dispatch_pseudothread(void* arg) { 
    fatal_errno("failed to create pipe");

  }



  uint32_t version;

  ssize_t expected;



  // ucontext_t is absurdly large on AArch64, so piece it together manually with writev.

  uint32_t version = 3;

  constexpr size_t expected = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataV3);

  struct iovec iovs[4] = {

      {.iov_base = &version, .iov_len = sizeof(version)},

      {.iov_base = thread_info->siginfo, .iov_len = sizeof(siginfo_t)},

      {.iov_base = thread_info->ucontext, .iov_len = sizeof(ucontext_t)},

  };



  if (thread_info->process_info.fdsan_table) {

    // Dynamic executables always use version 4. There is no need to increment the version number if

    // the format changes, because the sender (linker) and receiver (crash_dump) are version locked.

    version = 4;

    expected = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataDynamic);



    iovs[3] = {.iov_base = &thread_info->process_info,

               .iov_len = sizeof(thread_info->process_info)};

  } else {

    // Static executables always use version 1.

    version = 1;

    expected = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataStatic);



    iovs[3] = {.iov_base = &thread_info->process_info.abort_msg, .iov_len = sizeof(uintptr_t)};

  }

  errno = 0;

  if (fcntl(output_write.get(), F_SETPIPE_SZ, expected) < static_cast<int>(expected)) {

    fatal_errno("failed to set pipe buffer size");

  }



  struct iovec iovs[] = {

      {.iov_base = &version, .iov_len = sizeof(version)},

      {.iov_base = thread_info->siginfo, .iov_len = sizeof(siginfo_t)},

      {.iov_base = thread_info->ucontext, .iov_len = sizeof(ucontext_t)},

      {.iov_base = &thread_info->abort_msg, .iov_len = sizeof(uintptr_t)},

      {.iov_base = &thread_info->fdsan_table, .iov_len = sizeof(uintptr_t)},

      {.iov_base = &thread_info->gwp_asan_state, .iov_len = sizeof(uintptr_t)},

      {.iov_base = &thread_info->gwp_asan_metadata, .iov_len = sizeof(uintptr_t)},

  };



  ssize_t rc = TEMP_FAILURE_RETRY(writev(output_write.get(), iovs, arraysize(iovs)));

  if (rc == -1) {

    fatal_errno("failed to write crash info");
@@ -489,29 +497,19 @@ static void debuggerd_signal_handler(int signal_number, siginfo_t* info, void* c 
    // check to allow all si_code values in calls coming from inside the house.

  }



  void* abort_message = nullptr;

  const gwp_asan::AllocatorState* gwp_asan_state = nullptr;

  const gwp_asan::AllocationMetadata* gwp_asan_metadata = nullptr;

  debugger_process_info process_info = {};

  uintptr_t si_val = reinterpret_cast<uintptr_t>(info->si_ptr);

  if (signal_number == BIONIC_SIGNAL_DEBUGGER) {

    if (info->si_code == SI_QUEUE && info->si_pid == __getpid()) {

      // Allow for the abort message to be explicitly specified via the sigqueue value.

      // Keep the bottom bit intact for representing whether we want a backtrace or a tombstone.

      if (si_val != kDebuggerdFallbackSivalUintptrRequestDump) {

        abort_message = reinterpret_cast<void*>(si_val & ~1);

        process_info.abort_msg = reinterpret_cast<void*>(si_val & ~1);

        info->si_ptr = reinterpret_cast<void*>(si_val & 1);

      }

    }

  } else {

    if (g_callbacks.get_abort_message) {

      abort_message = g_callbacks.get_abort_message();

    }

    if (g_callbacks.get_gwp_asan_state) {

      gwp_asan_state = g_callbacks.get_gwp_asan_state();

    }

    if (g_callbacks.get_gwp_asan_metadata) {

      gwp_asan_metadata = g_callbacks.get_gwp_asan_metadata();

    }

  } else if (g_callbacks.get_process_info) {

    process_info = g_callbacks.get_process_info();

  }



  // If sival_int is ~0, it means that the fallback handler has been called
@@ -524,7 +522,7 @@ static void debuggerd_signal_handler(int signal_number, siginfo_t* info, void* c 
    // This check might be racy if another thread sets NO_NEW_PRIVS, but this should be unlikely,

    // you can only set NO_NEW_PRIVS to 1, and the effect should be at worst a single missing

    // ANR trace.

    debuggerd_fallback_handler(info, static_cast<ucontext_t*>(context), abort_message);

    debuggerd_fallback_handler(info, static_cast<ucontext_t*>(context), process_info.abort_msg);

    resend_signal(info);

    return;

  }
@@ -543,10 +541,7 @@ static void debuggerd_signal_handler(int signal_number, siginfo_t* info, void* c 
      .pseudothread_tid = -1,

      .siginfo = info,

      .ucontext = context,

      .abort_msg = reinterpret_cast<uintptr_t>(abort_message),

      .fdsan_table = reinterpret_cast<uintptr_t>(android_fdsan_get_fd_table()),

      .gwp_asan_state = reinterpret_cast<uintptr_t>(gwp_asan_state),

      .gwp_asan_metadata = reinterpret_cast<uintptr_t>(gwp_asan_metadata),

      .process_info = process_info,

  };



  // Set PR_SET_DUMPABLE to 1, so that crash_dump can ptrace us.

debuggerd/include/debuggerd/handler.h

+10 −3
Original line number Diff line number Diff line
@@ -33,13 +33,20 @@ struct AllocatorState; 
struct AllocationMetadata;

};  // namespace gwp_asan



// When updating this data structure, CrashInfoDataDynamic and the code in

// ReadCrashInfo() must also be updated.

struct debugger_process_info {

  void* abort_msg;

  void* fdsan_table;

  const gwp_asan::AllocatorState* gwp_asan_state;

  const gwp_asan::AllocationMetadata* gwp_asan_metadata;

};



// These callbacks are called in a signal handler, and thus must be async signal safe.

// If null, the callbacks will not be called.

typedef struct {

  struct abort_msg_t* (*get_abort_message)();

  debugger_process_info (*get_process_info)();

  void (*post_dump)();

  const struct gwp_asan::AllocatorState* (*get_gwp_asan_state)();

  const struct gwp_asan::AllocationMetadata* (*get_gwp_asan_metadata)();

} debuggerd_callbacks_t;



void debuggerd_init(debuggerd_callbacks_t* callbacks);

debuggerd/protocol.h

+4 −8
Original line number Diff line number Diff line
@@ -85,17 +85,14 @@ struct __attribute__((__packed__)) CrashInfoHeader { 
  uint32_t version;

};



struct __attribute__((__packed__)) CrashInfoDataV1 {

struct __attribute__((__packed__)) CrashInfoDataStatic {

  siginfo_t siginfo;

  ucontext_t ucontext;

  uintptr_t abort_msg_address;

};



struct __attribute__((__packed__)) CrashInfoDataV2 : public CrashInfoDataV1 {

struct __attribute__((__packed__)) CrashInfoDataDynamic : public CrashInfoDataStatic {

  uintptr_t fdsan_table_address;

};



struct __attribute__((__packed__)) CrashInfoDataV3 : public CrashInfoDataV2 {

  uintptr_t gwp_asan_state;

  uintptr_t gwp_asan_metadata;

};
@@ -103,8 +100,7 @@ struct __attribute__((__packed__)) CrashInfoDataV3 : public CrashInfoDataV2 { 
struct __attribute__((__packed__)) CrashInfo {

  CrashInfoHeader header;

  union {

    CrashInfoDataV1 v1;

    CrashInfoDataV2 v2;

    CrashInfoDataV3 v3;

    CrashInfoDataStatic s;

    CrashInfoDataDynamic d;

  } data;

};