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Commit 8bb03907 authored by Josh Gao's avatar Josh Gao
Browse files

crash_dump: add tracing. 

Add some tracing to figure out where time is going during a dump.

Bug: http://b/62112103
Test: systrace.py sched freq idle bionic
Change-Id: Ic2a212beeb0bb0350b4d9c2cd7a4e70adc97752d
parent 4db472b7

debuggerd/crash_dump.cpp

+58 −28
Original line number Diff line number Diff line
@@ -44,6 +44,9 @@ 
#include <private/android_filesystem_config.h>

#include <procinfo/process.h>



#define ATRACE_TAG ATRACE_TAG_BIONIC

#include <utils/Trace.h>



#include "backtrace.h"

#include "tombstone.h"

#include "utility.h"
@@ -101,6 +104,7 @@ static bool ptrace_seize_thread(int pid_proc_fd, pid_t tid, std::string* error) 
}



static bool activity_manager_notify(pid_t pid, int signal, const std::string& amfd_data) {

  ATRACE_CALL();

  android::base::unique_fd amfd(socket_local_client(

      "/data/system/ndebugsocket", ANDROID_SOCKET_NAMESPACE_FILESYSTEM, SOCK_STREAM));

  if (amfd.get() == -1) {
@@ -176,6 +180,7 @@ static void abort_handler(pid_t target, const bool tombstoned_connected, 
}



static void drop_capabilities() {

  ATRACE_CALL();

  __user_cap_header_struct capheader;

  memset(&capheader, 0, sizeof(capheader));

  capheader.version = _LINUX_CAPABILITY_VERSION_3;
@@ -194,6 +199,8 @@ static void drop_capabilities() { 
}



int main(int argc, char** argv) {

  atrace_begin(ATRACE_TAG, "before reparent");



  pid_t target = getppid();

  bool tombstoned_connected = false;

  unique_fd tombstoned_socket;
@@ -261,6 +268,8 @@ int main(int argc, char** argv) { 
    PLOG(FATAL) << "parent died";

  }



  atrace_end(ATRACE_TAG);



  // Reparent ourselves to init, so that the signal handler can waitpid on the

  // original process to avoid leaving a zombie for non-fatal dumps.

  pid_t forkpid = fork();
@@ -270,18 +279,23 @@ int main(int argc, char** argv) { 
    exit(0);

  }



  ATRACE_NAME("after reparent");



  // Die if we take too long.

  alarm(2);



  std::string attach_error;



  std::map<pid_t, std::string> threads;



  {

    ATRACE_NAME("ptrace");

    // Seize the main thread.

    if (!ptrace_seize_thread(target_proc_fd, main_tid, &attach_error)) {

      LOG(FATAL) << attach_error;

    }



    // Seize the siblings.

  std::map<pid_t, std::string> threads;

    {

      std::set<pid_t> siblings;

      if (!android::procinfo::GetProcessTids(target, &siblings)) {
@@ -301,16 +315,24 @@ int main(int argc, char** argv) { 
        }

      }

    }

  }



  // Collect the backtrace map, open files, and process/thread names, while we still have caps.

  std::unique_ptr<BacktraceMap> backtrace_map(BacktraceMap::Create(main_tid));

  std::unique_ptr<BacktraceMap> backtrace_map;

  {

    ATRACE_NAME("backtrace map");

    backtrace_map.reset(BacktraceMap::Create(main_tid));

    if (!backtrace_map) {

      LOG(FATAL) << "failed to create backtrace map";

    }

  }



  // Collect the list of open files.

  OpenFilesList open_files;

  {

    ATRACE_NAME("open files");

    populate_open_files_list(target, &open_files);

  }



  std::string process_name = get_process_name(main_tid);

  threads.emplace(main_tid, get_thread_name(main_tid));
@@ -318,9 +340,12 @@ int main(int argc, char** argv) { 
  // Drop our capabilities now that we've attached to the threads we care about.

  drop_capabilities();



  {

    ATRACE_NAME("tombstoned_connect");

    const DebuggerdDumpType dump_type_enum = static_cast<DebuggerdDumpType>(dump_type);

    LOG(INFO) << "obtaining output fd from tombstoned, type: " << dump_type_enum;

    tombstoned_connected = tombstoned_connect(target, &tombstoned_socket, &output_fd, dump_type_enum);

  }



  // Write a '\1' to stdout to tell the crashing process to resume.

  // It also restores the value of PR_SET_DUMPABLE at this point.
@@ -349,10 +374,13 @@ int main(int argc, char** argv) { 
  }



  siginfo_t siginfo = {};

  {

    ATRACE_NAME("wait_for_signal");

    if (!wait_for_signal(main_tid, &siginfo)) {

      printf("failed to wait for signal in tid %d: %s\n", main_tid, strerror(errno));

      exit(1);

    }

  }



  int signo = siginfo.si_signo;

  bool fatal_signal = signo != DEBUGGER_SIGNAL;
@@ -373,8 +401,10 @@ int main(int argc, char** argv) { 


  std::string amfd_data;

  if (backtrace) {

    ATRACE_NAME("dump_backtrace");

    dump_backtrace(output_fd.get(), backtrace_map.get(), target, main_tid, process_name, threads, 0);

  } else {

    ATRACE_NAME("engrave_tombstone");

    engrave_tombstone(output_fd.get(), backtrace_map.get(), &open_files, target, main_tid,

                      process_name, threads, abort_address, fatal_signal ? &amfd_data : nullptr);

  }