On Fri, 5 Jan 2007, Ceri Davies wrote:
On Fri, Jan 05, 2007 at 01:34:04PM +0000, Robert Watson wrote:
On Fri, 5 Jan 2007, Ceri Davies wrote:
Much as I would love to trust the contents of ub there, I suspect they
can't be trusted. Could you print the contents of *fp in kern_fstat() in
both of those stacks? I'd particularly like to know the value of
fp->f_type, and then depending on the type, possibly the contents of
*(struct vnode *)fp->f_vnode for DTYPE_VNODE/TYPE_FIFO or *(struct socket
*)fp->f_data in the case of DTYPE_SOCKET.
Can you tell me how to get at *fp given that the stack trace shows fstat()
and not kern_fstat()? Sorry if I'm being dumb but I don't know how to
step into the kern_fstat() call from fstat().
It could be that the stack is hosed losing the frame, or maybe it's inlined
(more likely the former I think, as kern_fstat() is a symbol used elsewhere
in the kernel). The best bet may be to use the file descriptor number
(uap->fd) to pull the struct file reference out of the process. Something
on the order of (td->td_proc->p_fd->fd_ofiles[fd]) should return the right
struct file *.
OK, got it. They're both sockets, data in the attachments.
How reproduceable is this?
So far it's happened this morning and yesterday morning. I haven't seen it
before that. I don't know the cause so I can't reproduce it at will, but
the logs don't give any indication. Chances are that it will happen again
tomorrow, but we'll see.
Hmm. It looks like you printf *(td->td_proc->p_fd->fd_ofiles) without the
array index. Could you repeat that, but with the array index -- i.e.,
td->td_proc->p_fd->fd_ofiles[uap->fd]? Also, it would probably be useful to
print uap->fd. Right now you're printing stdin (index 0), but if the index is
non-0, we want a different file.
thanks,
Robert N M Watson
Computer Laboratory
University of Cambridge
_______________________________________________
[email protected] mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "[EMAIL PROTECTED]"
