lkml.org 
[lkml]   [2012]   [Jun]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] tty: add lockdep annotations
From
Date
On Fri, 2012-06-01 at 21:56 +0100, Alan Cox wrote:
> > Yes, tty->driver deref is ok (tty points to valid memory), but crash is
> > on tty->driver->ops (driver points to freed/illegal memory)
> >
> > using slub_debug=FZPU, I can indeed see RDI=6b6b6b6b6b6b6b6b
>
> driver and driver->ops is basically const and it's not what you'd expect
> from a tty refcount bug. The driver side puts shouldn't have changed but
> I'll take a look over that patch and the error paths closely again just
> in case.

right

The code looks like :
...
call mcount
mov %rdi,%rbx
mov 0x10(%rdi),%rdi tty->driver
<> mov 0xf8(%rdi),%rax CRASH

So tty was freed an tty->driver contains 6b6b6b6b6b6b6b6b





\
 
 \ /
  Last update: 2012-06-01 23:21    [from the cache]
©2003-2011 Jasper Spaans