Re: utrace vs. ptrace

[Ingo Molnar <mingo@elte.hu>]

* Olaf Hering <olh@suse.de> wrote:

>  On Tue, Jul 25, Linus Torvalds wrote:
> 
> > What you often want is not a core-dump at all, but a "stop the process" 
> > thing. It's really irritating that the core-dump is generated and the 
> > process is gone, when it would often be a lot nicer if instead of 
> > core-dumping, the process was just stopped and then you could attach to it 
> > with gdb, and get the whole damn information (including things like access 
> > to open file descriptors etc).
> > 
> > But again, that has nothing to do with core-dumping. 
> 
> It would be helpful to have that sort of functionality in mainline. 
> Would a patch be acceptable that sends SIGSTOP instead of SIGSEGV or 
> SIGILL if some knob was enabled, either global or per process?

FYI, the sample utrace module from Roland does precisely that, it stops 
a task on crash... See more at:

  http://people.redhat.com/roland/utrace/

- crash-suspend.c is the sample module.

- ntrace-0.0.2.tar.bz2 is an extensive ptrace and utrace functionality 
  testsuite.

	Ingo