On 2010-11-09 21:15, Paul E. McKenney wrote: > On Tue, Nov 09, 2010 at 12:21:24PM +0200, Sergey Senozhatsky wrote: >> Commit 4221a9918e38b7494cee341dda7b7b4bb8c04bde "Add RCU check for >> find_task_by_vpid()" introduced rcu_lockdep_assert to find_task_by_pid_ns.. >> Assertion failed in sys_ioprio_get. The patch is fixing assertion >> failure in ioprio_set as well. >> >> kernel/pid.c:419 invoked rcu_dereference_check() without protection! >> >> stack backtrace: >> Pid: 4254, comm: iotop Not tainted >> Call Trace: >> [<ffffffff810656f2>] lockdep_rcu_dereference+0xaa/0xb2 >> [<ffffffff81053c67>] find_task_by_pid_ns+0x4f/0x68 >> [<ffffffff81053c9d>] find_task_by_vpid+0x1d/0x1f >> [<ffffffff811104e2>] sys_ioprio_get+0x50/0x2da >> [<ffffffff81002182>] system_call_fastpath+0x16/0x1b >> >> V2: rcu critical section expanded according to comment by Paul E. McKenne: >> | Looking over the patch again, the scope of the RCU read-side critical >> | section needs to expand to cover the use of the pointer as well as the >> | call to find_task_by_vpid(). > > Thank you, Sergey! > > Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> > > Jens, are you willing to take this one? Certainly, thanks guys! -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
