1  # How To Use Breakpad As a Coredump Handler on Linux
 2  
 3  This document presents a way to use Breakpad in order to generate
 4  minidumps system wide on Linux.
 5  
 6  Please refer to [Linux starter guide](./linux_starter_guide.md) if
 7  instead you want to integrate breakpad into your application.
 8  
 9  ## Motivation
10  
11  When working on an embedded system, disk and memory space is often
12  limited and when a process crashes it must be restarted as soon as
13  possible. Sometime saving a full coredump takes to much time or
14  consumes too much space.
15  
16  ## Breakpad Core Handler
17  
18  In such case the program `core_handler` can be use to generate
19  minidumps instead of coredumps. `core_handler` reads the firsts
20  sections of the coredump (where the various threads are described)
21  generated by Linux from the standard input and then directly reads
22  `/proc/<pid>/mem` to reconstruct the stacktraces.
23  
24  One can test it with:
25  
26  ```
27  # echo "|/usr/libexec/core_handler %P /var/lib/minidump/%e-%i.md" >
28                  /proc/sys/kernel/core_pattern
29  # echo 1 > /proc/sys/kernel/core_pipe_limit
30  ```
31  
32  Be aware that a real world integration would likely require further
33  customization and so `core_handler` can be wrapped into a script (for
34  example to change the permission of the minidump file or to signal the
35  presence of the minidump to another service).
36  
37  Please refer to
38  [core(5)](https://man7.org/linux/man-pages/man5/core.5.html) for more
39  details.