Re: 2.6.18-rt6

[Esben Nielsen <nielsen.esben@googlemail.com>]

On Wed, 18 Oct 2006, Ingo Molnar wrote:

> i've released the 2.6.18-rt6 tree, which can be downloaded from the
> usual place:
>
>  http://redhat.com/~mingo/realtime-preempt/
>
> this is a fixes-mostly release. Changes since -rt4:
>
> - fix for module loading / symbol table crash (John Stultz)
> - scheduler fix (Mike Galbraith)
> - fix x86_64 NMI watchdog & preempt-rcu interaction
> - fix time-warp false positives
> - jiffies_to_timespec export fix (Steven Rostedt)
> - ll_rw_block.c warning fix (Mike Galbraith)
> - PPC updates (Daniel Walker)
> - MIPS updates (Manish Lachwani)
> - ARM oprofile fix (Kevin Hilman)
> - traditional futexes queued via plists (Séstien Duguése)
> - (various other smaller fixes)

I assume this goes under small fixes:

I see that
	spin_lock(&pi_state->pi_mutex.wait_lock);
is added in futex.c:570 in wake_futex_pi().
I do but I see some missing unlocks at returns.

I have a totally untested (it compiles) patch below.

Esben

 kernel/futex.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Index: linux-2.6.18-rt/kernel/futex.c
===================================================================
--- linux-2.6.18-rt.orig/kernel/futex.c
+++ linux-2.6.18-rt/kernel/futex.c
@@ -590,10 +590,14 @@ static int wake_futex_pi(u32 __user *uad
 		inc_preempt_count();
 		curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval);
 		dec_preempt_count();
-		if (curval == -EFAULT)
+		if (curval == -EFAULT) {
+			spin_unlock(&pi_state->pi_mutex.wait_lock);
 			return -EFAULT;
-		if (curval != uval)
+		}
+		if (curval != uval) {
+			spin_unlock(&pi_state->pi_mutex.wait_lock);
 			return -EINVAL;
+		}
 	}

 	spin_lock_irq(&pi_state->owner->pi_lock);