Re: [v3.0 stable version][PATCH 1/2] ring-buffer: Fix NULL pointer if rb_set_head_page() fails

[Greg KH <greg@kroah.com>]

On Thu, Dec 06, 2012 at 04:41:55PM -0500, Steven Rostedt wrote:
> On Thu, 2012-12-06 at 12:13 -0800, Greg KH wrote:
> > On Fri, Nov 30, 2012 at 11:16:43AM -0500, Steven Rostedt wrote:
> > > The function rb_set_head_page() searches the list of ring buffer
> > > pages for a the page that has the HEAD page flag set. If it does
> > > not find it, it will do a WARN_ON(), disable the ring buffer and
> > > return NULL, as this should never happen.
> > > 
> > > But if this bug happens to happen, not all callers of this function
> > > can handle a NULL pointer being returned from it. That needs to be
> > > fixed.
> > > 
> > > Cc: stable@vger.kernel.org # 3.0+
> > > Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
> > > ---
> > >  kernel/trace/ring_buffer.c |    9 +++++++--
> > >  1 files changed, 7 insertions(+), 2 deletions(-)
> > 
> > I don't understand why you sent these to stable@ right now, I don't see
> > them in Linus's tree, so why are they needed here?
> 
> Answer below.
> 
> > 
> > Care to resend them when they hit Linus's tree?
> 
> I'll try to remember, but I will most likely forget :-)
> 
> I wrote the patches for each stable version while they were still fresh
> in my mind. I posted them so they would be there when they get into
> mainline and be easier to port for stable. By the time they are in
> mainline, they will be completely out of my mind :-)

Ok, if they are that important, consider them forgotten from my mind as
well :)

greg k-h