[Differential] [Commented On] D1711: Changes to the callout code to restore active semantics and also add a test-framework and test to validate thecallout code (and potentially for use by other tests).

[hiren (hiren panchasara)]

hiren added a comment.

>>! In D1711#59, @rrs wrote:
> Hiren:
> 
> Ok looking at kern_timeout.c thats a call to 
> class->lc_lock(c_lock, lock_status);
> 
> If my 10.x matches yours.
> 
> And the call inside that kern_rwlock.c:757 
> is
> 
> v = rw->rw_lock;
> owner = (struct thread *)RW_OWNER(v);
> 
> I would imagine v is probably a freed lock or some such.. not sure.
> If you have a vmcore sending the registers would be helpful. And for that 
> matter if you have a vmcore if you could get in the frame of kern_timeout
> and tell me what
> c_lock
> c_func
> are that would be helpful. I have not tested this with my test framework for locks
> that pass in a lock.. If the c_func is not some private thing but something in
> BSD I can puzzle out what sub-system is using the callout this way and
> try to reproduce a test that will blow up this way on me as well.
> 
> Assuming of course its not the caller that has freed the
> lock ahead of the callout system running...

panic #3 happened on stable-10+this patch. 
I've setup a -head box with this patch to reproduce the problem.
In any case, I'll try to get vmcore and other details tomorrow.

REVISION DETAIL
  https://reviews.freebsd.org/D1711

To: rrs, gnn, rwatson, lstewart, jhb, kostikbel, hselasky, adrian, imp, sbruno
Cc: hiren, jhb, kostikbel, emaste, delphij, neel, erj, freebsd-net