Messages in this thread | | | From | David Howells <> | Subject | Re: [PATCH 0/4] coredump: core dump masking support v3 | Date | Mon, 26 Feb 2007 11:49:14 +0000 |
| |
Markus Gutschke <markus@google.com> wrote:
> > How does it work when you can't actually get back to userspace to have > > userspace do the coredump? You still have to handle the userspace > > equivalents of double/triple faults. > > My experience shows that there are only very rare occurrences of situations > where you cannot get back into userspace to do the coredump, and the > coredumper tries very hard never to cause additional faults.
So what? If they can occur, you have to handle them.
> While I am sure you could construct scenarios where this would happen, > realistically the only one I have run into were stack overflows, and they can > be handled by carefully setting up an alternate stack for signal handlers -- > just make sure the entire stack is already dirtied before you run out of > memory (or, turn of overcommitting).
Duff SIGSEGV or SIGBUS signal handlers are just as realistic. All that takes is for someone to make a programming error. Remember: error paths are the least frequently tested.
And any time you say "by carefully setting up" you can guarantee someone's going to do it wrong.
David - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |