Re: [for-next][PATCH v2 1/3] tracing: Fix syscall_*regfunc() vs copy_process() race

From: Steven Rostedt
Date: Fri Jun 20 2014 - 21:19:45 EST


On Fri, 20 Jun 2014 18:11:25 -0700
"Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> wrote:

> On Fri, Jun 20, 2014 at 06:45:19AM -0400, Steven Rostedt wrote:
> > From: Oleg Nesterov <oleg@xxxxxxxxxx>
> >
> > syscall_regfunc() and syscall_unregfunc() should set/clear
> > TIF_SYSCALL_TRACEPOINT system-wide, but do_each_thread() can race
> > with copy_process() and miss the new child which was not added to
> > the process/thread lists yet.
> >
> > Change copy_process() to update the child's TIF_SYSCALL_TRACEPOINT
> > under tasklist.
> >
> > Link: http://lkml.kernel.org/p/20140413185854.GB20668@xxxxxxxxxx
> >
> > Cc: stable@xxxxxxxxxxxxxxx # 2.6.33
> > Fixes: a871bd33a6c0 "tracing: Add syscall tracepoints"
> > Acked-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> > Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
> > Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
>
> Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
>

I don't usually rebase my for-next branch for acks, but I already
rebased once for fixing an issue, and it's early in the rc cycle, and
this is the first patch on the branch, so I think I will do it.

Thanks!

-- Steve
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