Here are a few principles that must be taken into account while developing CRIU.
- All shared resources must be restored by the task with the lowest PID among the group to avoid deadlocks.
- No operations with file paths in restorer blob — task has restored its fs (cwd and root) and may see a different tree.
- In dumping code, any fork()+exec() should be done using the cr_system() helper to avoid interfering with victim task tracing.
Protobuf images compatibility
To retain backward compatibility of protobuf image files, follow these rules:
- Don't change the numeric tags for any existing fields.
- Any new fields that you add should be optional or repeated.
- Non-required fields can be removed, as long as the tag number is not used again in your updated message type.
For more info, see protobuf messages updating guide.