Summary of Common Principles of Adb Bugreport

1. Use the scene
Use adb bugreport to export the files needed for power analysis and then perform a more detailed analysis at https://github.com/google/battery-historian

adb bugreport > Bugreport.zip
adb bugreport > Bugreport.txt

adb bugreport - return all information from the device that should be included in a bug report.

 " bugreport [PATH]\n"
    "     write bugreport to given PATH [default=bugreport.zip];\n"
    "     if PATH is a directory, the bug report is saved in that directory.\n"
    "     devices that don't support zipped bug reports output to stdout.\n"

I mainly want to know where the data of bugreport is derived.

2. bugreport data source
2.1 Receiving point issued by the adb bugreport command
System/core/adb/commandline.cpp

Command line receiving event view

#include "bugreport.h"

int adb_commandline(int argc, const char** argv) {

    ...
    } else if (!strcmp(argv[0], "bugreport")) {
    Bugreport bugreport;
    return bugreport.DoIt(argc, argv);
    ....

2.2 bugreport.DoIt(argc, argv)
system/core/adb/bugreport.cpp

int Bugreport::DoIt(int argc, const char** argv) {
    ...
    return SendShellCommand(bugz_command, false, &bugz_callback);
}

2.3 Executing an Execution File
Corresponding to the executable file in the system directory

/system/bin # ls -al

-rwxr-xr-x  1 root   shell      10264 2018-05-31 15:18 bugreport
-rwxr-xr-x  1 root   shell      10264 2018-05-31 15:18 bugreportz

Frameworks\native\cmds\bugreport\bugreport.cpp

2.4 Reading bugreport information
In fact, bugreport is dumpstate, the specific file is in the mobile system directory system/bin/dumpstate, dumpstate is the executable file.

• Cmd window
  

  Sufadi:/system/bin # ls dumpstate -all
  ls dumpstate -all
  -rwxr-xr-x 1 root shell 207136 2018-05-31 15:18 dumpstate

• Specific source code
  

  // This program will trigger the dumpstate service to start a call to
  // dumpstate, then connect to the dumpstate local client to read the
  // output. All of the dumpstate output is written to stdout, including
  // any errors encountered while reading/writing the output.
  int main() {
    ...
    // Start the dumpstate service. 启动 dumpstate service
    // 其实bugreport就是 dumpstate 
    property_set("ctl.start", "dumpstate");
  
    ...
  
    while (1) {
      ...
      char buffer[65536];
      ssize_t bytes_read = TEMP_FAILURE_RETRY(read(s, buffer, sizeof(buffer)));
  
      do {
        bytes_written = TEMP_FAILURE_RETRY(write(STDOUT_FILENO,
                                                 buffer + bytes_read - bytes_to_send,
                                                 bytes_to_send));
        if (bytes_written == -1) {
          printf("Failed to write data to stdout: read %zd, trying to send %zd (%s)\n",
                 bytes_read, bytes_to_send, strerror(errno));
          return 1;
        }
        bytes_to_send -= bytes_written;
      } while (bytes_written != 0 && bytes_to_send > 0);
    }
  
    close(s);
    return 0;
  }

2.5 dumpstate implementation and its data source
Frameworks\native\cmds\dumpstate\dumpstate.cpp

• 1. System properties
• 2./proc and /sys node files
• 3. Execute the shell command to get the relevant output
• 4.logcat output
• 5.Android Framework Services information basically uses the dumpsys command to obtain information through the dump function in the binder call service.

Above, for example
- View battery information
RunDumpsys("CHECKIN BATTERYSTATS", {"batterystats", "-c"});

View kernal's wakeup source
DumpFile("KERNEL WAKE SOURCES", "/d/wakeup_sources");
3. bugreport data display
Export mobile phone data from bugreport, parsing raw data through battery-historian for multi-dimensional analysis of power consumption anomalies