From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Thu, 15 Dec 2011 06:48:05 +0000 Subject: [patch] sgi-xp: nested calls to spin_lock_irqsave() Message-Id: <20111215064805.GA2776@elgon.mountain> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Robin Holt Cc: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org The code here has a nested spin_lock_irqsave(). It's not needed since IRQs are already disabled and it causes a problem because it means that IRQs won't be enabled again at the end. The second call to spin_lock_irqsave() will overwrite the value of irq_flags and we can't restore the proper settings. Signed-off-by: Dan Carpenter --- This is a static checker fix. It's possible that no one hits this bug in real life if the function is always called with IRQs disabled. diff --git a/drivers/misc/sgi-xp/xpc_uv.c b/drivers/misc/sgi-xp/xpc_uv.c index 17bbacb..87b251a 100644 --- a/drivers/misc/sgi-xp/xpc_uv.c +++ b/drivers/misc/sgi-xp/xpc_uv.c @@ -452,9 +452,9 @@ 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; }