This series is an RFC for utrace-based non-disruptive application core dumper. Per Roland McGrath, this is possibly one of the common use-cases for utrace.
This is the first foray of mine into the hairy core dump land. Admittedly, I may have missed some (not so) subtle issues that need careful consideration. The current implementation uses a /proc trigger. Every process gains a new /proc/<pid>/gen_core 'write-only' file. Echoing a value of '1' will cause the core-dump to be generated. As with fatal core-dumps, the core file will be saved in the same directory as the location from where the application was started. The core dump has a format core.<pid>.<timestamp>, where the timestamp is the value of ktime_get() at the time of calling the binfmt->core_dump(). The current implementation uses a completion(). However, this precludes the possibility of a process syncrhonously asking for its own dump (trying this usecase causes the application to hang indefinitely). I am told this is a much needed feature that Linux lacks. Awaiting comments... Regards, Ananth
