ACRN-Crashlog

Introduction

ACRN-Crashlog is a collective name for various tools (acrnprobe, usercrash_s, usercrash_c, debugger, and more) and an overall control utility called crashlogctl. Together these tools collect logs and information after each crash or event on an ACRN platform, including the hypervisor, Service VM, and Android as a Guest (AaaG). ACRN-Crashlog provides a flexible way to configure which events are of interest, by using an XML configuration file.

Building

Build Dependencies

The ACRN-Crashlog tool depends on the following libraries (build and runtime):

  • libevent

  • OpenSSL

  • libxml2

  • systemd

  • libblkid

  • e2fsprogs

Refer to the Getting Started for instructions on how to set up your build environment, and follow the instructions below to build and configure the ACRN-Crashlog tool.

Build

To build the ACRN-Crashlog, run:

cd misc/debug_tools/acrn_crashlog
make

To remove all generated files and return the folder to its clean state, use:

cd misc/debug_tools/acrn_crashlog
make clean

Installing

To install the build:

cd misc/debug_tools/acrn_crashlog
sudo make install

Enabling/Disabling

To enable this tool:

sudo crashlogctl enable

Then it will show:

... Backup core pattern to /var/log/crashlog/default_core_pattern
'/usr/share/acrn/crashlog/40-watchdog.conf' ->
'/etc/systemd/system.conf.d/40-watchdog.conf'
'/usr/share/acrn/crashlog/80-coredump.conf' ->
'/etc/sysctl.d/80-coredump.conf'
Created symlink /etc/systemd/system/multi-user.target.wants/acrnprobe.service -> /usr/lib/systemd/system/acrnprobe.service.
Created symlink /etc/systemd/system/multi-user.target.wants/usercrash.service -> /usr/lib/systemd/system/usercrash.service.
*** Please reboot your system. ***

Follow the hints to reboot the system:

sudo reboot

To disable this tool:

sudo crashlogctl disable

Then it will show:

Removed /etc/systemd/system/multi-user.target.wants/acrnprobe.service.
Removed /etc/systemd/system/multi-user.target.wants/usercrash.service.
removed '/etc/sysctl.d/80-coredump.conf'
removed '/etc/systemd/system.conf.d/40-watchdog.conf'
*** Please reboot your system. ***

Follow the hints to reboot the system:

sudo reboot

To check the status of this tool:

sudo crashlogctl is-active

It will show the status of the related services. Example:

acrnprobe  : inactive
usercrash  : inactive

Usage

The acrnprobe tool provides history_event (under /var/log/crashlog/history_event) to record ACRN-related events and crash information.

ACRN-Crashlog also provides a tool called debugger to dump specific process information:

sudo debugger 12

Replace 12 with the process ID you want to dump.

Note

You need to be root to use the debugger.

Source Code

The source code structure:

acrn-crashlog/
├── acrnprobe
│   └── include
├── common
│   └── include
├── data
└── usercrash
    └── include

  • acrnprobe: tool that gathers all the crash and event logs on the platform. For the hypervisor, the log is collected with acrnlog. For the Service VM, the userspace crash log is collected with usercrash, and the kernel crash log is collected with the inherent mechanism, such as ipanic or pstore. For an AaaG VM, the log is collected by monitoring the change of related folders on the Service VM image, such as /data/logs/. acrnprobe also provides a flexible way to configure which crash or event to collect, by using an XML configuration file.

  • common: some utils for logs, command and string.

  • data: configuration file, service files and shell script.

  • usercrash: tool that gets the crash information for the crashing process in userspace.

Acrnprobe

The acrnprobe tool detects all critical events on the platform and collects specific information for debug purposes. The information is saved as logs. For more details on acrnprobe, see Acrnprobe.

Usercrash

The usercrash tool gets the crash information of the crashing process in userspace. It works in a client/server model. The server is autostarted, and the client is configured in core_pattern or coredump-wrapper, which will be triggered once a crash occurs in userspace. For more details on usercrash, see Usercrash.