Re: utrace vs. ptrace

Ingo Molnar
2006-07-25T19:18:42Z

* 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