Re: Kernel Oops-jprobe

Balbir Singh
2006-03-17T11:11:40Z

> > I think the handler should first copy_from_user().
>
> User must not call copy_from_user() in the handler, since preemption is
> disabled and the copy_from_user might cause a page fault that might
> sleep if the user page is not in the memory. Although the latest patch
> posted on lkml tries to fixup the exception, it may some
> times not succeed and the data collected might be incorrect.
>
Yes, you are right. I forgot about the probe handler requirements. In
that case you need to come up with your own trick to get the user
space data. Also look at/use systemtap.

Balbir