From: Simon Horman <horms@kernel.org>
To: Chengfeng Ye <dg573847474@gmail.com>
Cc: 3chas3@gmail.com, davem@davemloft.net,
linux-atm-general@lists.sourceforge.net, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/2] atm: solos-pci: Fix potential deadlock on &tx_queue_lock
Date: Sat, 7 Oct 2023 17:13:28 +0200 [thread overview]
Message-ID: <20231007151328.GD831234@kernel.org> (raw)
In-Reply-To: <20231005074917.65161-1-dg573847474@gmail.com>
On Thu, Oct 05, 2023 at 07:49:17AM +0000, Chengfeng Ye wrote:
> As &card->tx_queue_lock is acquired under softirq context along the
> following call chain from solos_bh(), other acquisition of the same
> lock inside process context should disable at least bh to avoid double
> lock.
>
> <deadlock #2>
> pclose()
> --> spin_lock(&card->tx_queue_lock)
> <interrupt>
> --> solos_bh()
> --> fpga_tx()
> --> spin_lock(&card->tx_queue_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 uses spin_lock_irqsave()
> on &card->tx_queue_lock under process context code consistently to
> prevent the possible deadlock scenario.
>
> Fixes: 213e85d38912 ("solos-pci: clean up pclose() function")
> Signed-off-by: Chengfeng Ye <dg573847474@gmail.com>
> ---
> V2: add fix tag, and split into two patches
Reviewed-by: Simon Horman <horms@kernel.org>
prev parent reply other threads:[~2023-10-07 15:13 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-05 7:49 [PATCH v2 2/2] atm: solos-pci: Fix potential deadlock on &tx_queue_lock Chengfeng Ye
2023-10-07 15:13 ` Simon Horman [this message]
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