You reason description confused me at first. After looking closer at the code, I understand and agree. Acked-by: Robin Holt <holt@xxxxxxx> On Sat, Jul 18, 2009 at 05:23:57PM +0200, Julia Lawall wrote: > From: Julia Lawall <julia@xxxxxxx> > > If spin_lock_irqsave is called twice in a row with the same second > argument, the interrupt state at the point of the second call overwrites > the value saved by the first call. Indeed, the second call does not need > to save the interrupt state, so it is changed to a simple spin_lock. > > The semantic match that finds this problem is as follows: > (http://www.emn.fr/x-info/coccinelle/) > > // <smpl> > @@ > expression lock1,lock2; > expression flags; > @@ > > *spin_lock_irqsave(lock1,flags) > ... when != flags > *spin_lock_irqsave(lock2,flags) > // </smpl> > > Signed-off-by: Julia Lawall <julia@xxxxxxx> > > --- > drivers/misc/sgi-xp/xpc_uv.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/misc/sgi-xp/xpc_uv.c b/drivers/misc/sgi-xp/xpc_uv.c > index c76677a..d0052ad 100644 > --- a/drivers/misc/sgi-xp/xpc_uv.c > +++ b/drivers/misc/sgi-xp/xpc_uv.c > @@ -443,9 +443,9 @@ xpc_handle_activate_mq_msg_uv(struct xpc_partition *part, > > if (msg->activate_gru_mq_desc_gpa != > part_uv->activate_gru_mq_desc_gpa) { > - spin_lock_irqsave(&part_uv->flags_lock, irq_flags); > + spin_lock(&part_uv->flags_lock); > part_uv->flags &= ~XPC_P_CACHED_ACTIVATE_GRU_MQ_DESC_UV; > - spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags); > + spin_unlock(&part_uv->flags_lock); > part_uv->activate_gru_mq_desc_gpa = > msg->activate_gru_mq_desc_gpa; > } > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
