Date: Sun, 02 Jun 2002 08:28:16 -0400 (EDT) From: John Baldwin <jhb@FreeBSD.org> To: kai ouyang <oykai@msn.com> Cc: current@FreeBSD.org Subject: RE: Help: from proc to thread? Message-ID: <XFMail.20020602082816.jhb@FreeBSD.org> In-Reply-To: <OE50nubN6sBPo5X3a5i0000fbb5@hotmail.com>
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On 02-Jun-2002 kai ouyang wrote:
> Based on the explain of the thread: struct proc *td_proc; /* Associated process. */ in the struct
> thread.
> and refer to the CCD code.
> I modify this function as following:
> int raidlookup(path, td, vpp)
> char *path;
> struct thread *td;
> struct vnode **vpp; /* result */
> {
> struct nameidata nd;
> struct vnode *vp;
> struct vattr va;
> struct proc *p;
> int error, flags;
> /* Sanity check the p_fd fields. This is really just a hack */
> p = td->td_proc;
So it dies here?
> Now the system will be crash , when it excutes the "p = td->td_proc".
> the system Information is :
> kernel: type 12 trap, code=0
> Stopped at raidlookup+0x19: movl 0(%eax),%ebx
Hmm, can you get the 'faulting va (virtual address)' error message that it
prints out?
Add a line to the beginning of the function as a sanity check that does:
KASSERT(td != NULL, "thread is null");
and compile your kernel with invariants and see if it panics with
"thread is null".
--
John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve!" - http://www.FreeBSD.org/
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