Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
SPDX-License-Identifier: BSD-3-Clause-Clear

Overall

We have developed the plugins that can gather more information based on crash-utility, including both kernel space and user space. This enhances our debugging efficiency.

How to start

sudo apt-get install cmake  // cmake >= 3.21.1

$ sudo apt-get install gcc-multilib g++-multilib

How to build

We support both single-module and multi-module compilation, managed through BUILD_TARGET_TOGETHER in build.sh.

single-module (by defalut)

cmake -DCMAKE_C_COMPILER="/usr/bin/gcc"   \
      -DCMAKE_CXX_COMPILER="/usr/bin/g++" \
      -DCMAKE_BUILD_TYPE="Debug"          \
      -DCMAKE_BUILD_TARGET_ARCH="arm64"   \
      -DBUILD_TARGET_TOGETHER="1"         \
      CMakeLists.txt                      \
      -B output/arm64

multi-module

cmake -DCMAKE_C_COMPILER="/usr/bin/gcc"   \
      -DCMAKE_CXX_COMPILER="/usr/bin/g++" \
      -DCMAKE_BUILD_TYPE="Debug"          \
      -DCMAKE_BUILD_TARGET_ARCH="arm64"   \
      CMakeLists.txt                      \
      -B output/arm64

Build

$ ./build.sh

How to use

To load the module's commands to a running crash-8.0.4+ session, enter:

crash> extend <path-to>/output/arm64/plugins.so or extend <path-to>/output/arm64/${module}.so

Supprot command:

command	arm64	arm
cma	x	x
buddy	x	x
memblock	x	x
reserved	x	x
vmalloc	x	x
binder	x	x
dts	x	x
procrank	x	x
coredump	x	x
workqueue	x	x
slub	x	x
zram	x	x
partition	x	x
pageowner	x	x
meminfo	x	x

usage

crash> help binder

NAME
  binder - dump binder log information

SYNOPSIS
  binder -a
  binder -p [pid]
  binder -l
  binder -f
  binder -n
  binder -b
  binder -t
  binder -r


DESCRIPTION
  This command dumps the binder log information of a specified process.
       -p  pid argument.


EXAMPLES
  Display all binder proc states:
    crash> binder -a
       proc 7312
       context hwbinder
           thread 7335: l 00 need_return 0 tr 0


  Display specific process binder states:
    crash> binder -p 7312
       proc 7312
       context hwbinder
           thread 7335: l 00 need_return 0 tr 0

crash> binder -r
binder_proc:0xffffff801a432c00 ndroid.contacts [4346] binder dead:0 frozen:0 sr:0 ar:0 max:15 total:6 requested:0 started:2 ready:3
  binder_ref:0xffffff806c9b0c00 id:117829 desc:7 s:1 w:1 death:0x0 -> node_id:6183 binder_proc:0xffffff80195ed000 system_server[1047]
  binder_ref:0xffffff806883a180 id:117825 desc:3 s:1 w:1 death:0x0 -> node_id:4022 binder_proc:0xffffff80195ed000 system_server[1047]
  binder_ref:0xffffff8067788000 id:117799 desc:1 s:1 w:1 death:0x0 -> node_id:5525 binder_proc:0xffffff80195ed000 system_server[1047]
  binder_ref:0xffffff805a317000 id:117762 desc:0 s:1 w:1 death:0x0 -> node_id:1 binder_proc:0xffffff801de62800 servicemanager[446]
  binder_ref:0xffffff806883ad00 id:117824 desc:2 s:1 w:1 death:0x0 -> node_id:4413 binder_proc:0xffffff80195ed000 system_server[1047]
  binder_ref:0xffffff8046048400 id:117827 desc:5 s:1 w:1 death:0x0 -> node_id:8305 binder_proc:0xffffff80195ed000 system_server[1047]
  binder_ref:0xffffff8066a2b700 id:117826 desc:4 s:1 w:1 death:0x0 -> node_id:5906 binder_proc:0xffffff80195ed000 system_server[1047]

How to develop

1. Add the header file: demo.h

// Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
// SPDX-License-Identifier: BSD-3-Clause-Clear

#ifndef DEMO_DEFS_H_
#define DEMO_DEFS_H_

#include "plugin.h"

class Demo: public PaserPlugin {
public:
    Demo();

    void cmd_main(void) override;
    DEFINE_PLUGIN_INSTANCE(Demo)
};

#endif // DEMO_DEFS_H_

2. Add the Demo.cpp file

// Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
// SPDX-License-Identifier: BSD-3-Clause-Clear

#include "demo.h"

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpointer-arith"

#ifndef BUILD_TARGET_TOGETHER
DEFINE_PLUGIN_COMMAND(Demo)
#endif

void Demo::cmd_main(void) {
    int c;
    if (argcnt < 2) cmd_usage(pc->curcmd, SYNOPSIS);
    while ((c = getopt(argcnt, args, "a")) != EOF) {
		switch(c) {
            case 'a':
                do_somethins();
                break;
            default:
                argerrs++;
                break;
		}
	}
    if (argerrs)
		cmd_usage(pc->curcmd, SYNOPSIS);
}

Demo::Demo():PaserPlugin(){
    cmd_name = "demo";
    help_str_list={
	"demo",					/* command name */
	"your description",		/* short description */
    };
    initialize();
}

#pragma GCC diagnostic pop

3. Add the build rule in CMakeLists.txt, it will output the demo.so, now you can use it.

add_library(demo SHARED
            ${PLUGIN_SOURCES}
            demo.cpp)
set_target_properties(demo PROPERTIES PREFIX "")

4. if you want to add the module to single-module. please follow the steps in plugins.cpp

• include your header file

  #include "demo.h"
  

• Add the global unique_ptr

  std::unique_ptr<Demo>   Demo::instance = nullptr;
  

• register your module in function plugin_init

  { &Demo::instance->cmd_name[0], &Demo::wrapper_func, Demo::instance->cmd_help, 0 },
  

• Destory your module in function plugin_fini

  Demo::instance.reset();
  

• Add the build rule in CMakeLists.txt

  list(APPEND PLUGIN_SOURCES
          ...
          demo.cpp)
  

Tested Kernels

• 5.4 to 6.6

Related Links

• https://github.com/quic/crash-plugins.git

Author

• [email protected]