From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jia-Ju Bai Subject: Re: [PATCH] infiniband: core: mad: Fix a sleep-in-atomic-context bug in ib_mad_recv_done() Date: Mon, 3 Sep 2018 09:41:06 +0800 Message-ID: References: <20180901120659.32509-1-baijiaju1990@gmail.com> <20180902203229.GA13946@ziepe.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180902203229.GA13946@ziepe.ca> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Jason Gunthorpe Cc: dledford@redhat.com, leon@kernel.org, ira.weiny@intel.com, pravin.shedge4linux@gmail.com, hal@mellanox.com, parav@mellanox.com, haakon.bugge@oracle.com, bart.vanassche@sandisk.com, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-rdma@vger.kernel.org On 2018/9/3 4:32, Jason Gunthorpe wrote: > On Sat, Sep 01, 2018 at 08:06:59PM +0800, Jia-Ju Bai wrote: >> The driver may sleep with holding a spinlock. >> >> The function call paths (from bottom to top) in Linux-4.16 are: >> >> [FUNC] alloc_mad_private(GFP_KERNEL) >> drivers/infiniband/core/mad.c, 2264: >> alloc_mad_private in ib_mad_recv_done >> drivers/infiniband/core/cq.c, 45: >> [FUNC_PTR]ib_mad_recv_done in __ib_process_cq >> drivers/infiniband/core/cq.c, 77: >> __ib_process_cq in ib_process_cq_direct >> drivers/infiniband/ulp/srp/ib_srp.c, 2010: >> ib_process_cq_direct in __srp_get_tx_iu >> drivers/infiniband/ulp/srp/ib_srp.c, 2353: >> __srp_get_tx_iu in srp_queuecommand >> drivers/infiniband/ulp/srp/ib_srp.c, 2352: >> _raw_spin_lock_irqsave in srp_queuecommand >> >> [FUNC] alloc_mad_private(GFP_KERNEL) >> drivers/infiniband/core/mad.c, 2264: >> alloc_mad_private in ib_mad_recv_done >> drivers/infiniband/core/cq.c, 45: >> [FUNC_PTR]ib_mad_recv_done in __ib_process_cq >> drivers/infiniband/core/cq.c, 77: >> __ib_process_cq in ib_process_cq_direct > This trace doesn't seem right, the CQ used by SRP will never have > ib_mad_recv_done as a function pointer. Okay, sorry for this false positive. Best wishes, Jia-Ju Bai