[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20231023160110.GA886087@nvidia.com>
Date: Mon, 23 Oct 2023 13:01:10 -0300
From: Jason Gunthorpe <jgg@...dia.com>
To: Chengfeng Ye <dg573847474@...il.com>,
dennis.dalessandro@...nelisnetworks.com
Cc: leon@...nel.org, dean.luick@...nelisnetworks.com,
linux-rdma@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] IB/hfi1: Fix potential deadlock on &irq_src_lock and
&dd->uctxt_lock
On Tue, Sep 26, 2023 at 10:11:16AM +0000, Chengfeng Ye wrote:
> handle_receive_interrupt_napi_sp() running inside interrupt handler
> could introduce inverse lock ordering between &dd->irq_src_lock
> and &dd->uctxt_lock, if read_mod_write() is preempted by the isr.
>
> [CPU0] | [CPU1]
> hfi1_ipoib_dev_open() |
> --> hfi1_netdev_enable_queues() |
> --> enable_queues(rx) |
> --> hfi1_rcvctrl() |
> --> set_intr_bits() |
> --> read_mod_write() |
> --> spin_lock(&dd->irq_src_lock) |
> | hfi1_poll()
> | --> poll_next()
> | --> spin_lock_irq(&dd->uctxt_lock)
> |
> | --> hfi1_rcvctrl()
> | --> set_intr_bits()
> | --> read_mod_write()
> | --> spin_lock(&dd->irq_src_lock)
> <interrupt> |
> --> handle_receive_interrupt_napi_sp() |
> --> set_all_fastpath() |
> --> hfi1_rcd_get_by_index() |
> --> spin_lock_irqsave(&dd->uctxt_lock) |
>
> This flaw was found by an experimental static analysis tool I am
> developing for irq-related deadlock.
>
> To prevent the potential deadlock, the patch use spin_lock_irqsave()
> on &dd->irq_src_lock inside read_mod_write() to prevent the possible
> deadlock scenario.
>
> Signed-off-by: Chengfeng Ye <dg573847474@...il.com>
> ---
> drivers/infiniband/hw/hfi1/chip.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
Dennis? This needs your ack/nack
Thanks,
Jason
Powered by blists - more mailing lists