Date: Wed, 11 Nov 2015 00:53:07 -0500
From: "ira.weiny" <ira.weiny@intel.com>
To: Alexey Khoroshilov <khoroshilov@ispras.ru>
Cc: Mike Marciniszyn <infinipath@intel.com>,
        Doug Ledford <dledford@redhat.com>, Sean Hefty <sean.hefty@intel.com>,
        Hal Rosenstock <hal.rosenstock@gmail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-rdma@vger.kernel.org, devel@driverdev.osuosl.org,
        linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org
Subject: Re: [BUG] IB/hfi1: might sleep under spinlock in hfi1_ioctl()
Message-ID: <20151111055305.GA9594@phlsvsds.ph.intel.com>
References: <1446240749-5003-1-git-send-email-khoroshilov@ispras.ru> <20151030235817.GA13800@phlsvsds.ph.intel.com>
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On Fri, Oct 30, 2015 at 07:58:18PM -0400, ira. weiny wrote:
> On Sat, Oct 31, 2015 at 12:32:29AM +0300, Alexey Khoroshilov wrote:
> > Hello,
> > 
> > hfi1_ioctl() contains many calls to might sleep functions with
> > dd->hfi1_snoop.snoop_lock spinlock held (for example, access_ok,
> > copy_from_user, kzalloc(GFP_KERNEL), etc.).
> > 
> > Should dd->hfi1_snoop.snoop_lock be acquired just before updating state?
> 
> I believe you are correct.
> 
> I am currently in the process of pushing fixes to the staging tree.
> 
> We have a patch which fixes this queued up but it depends on at least one other
> patch in my queue.
> 
> I will do my best to get this submitted soon.

I have just posted a series which addresses this problem as well as doing
general clean up on hfi1_ioctl.  The specific fix is contained in this patch.

[PATCH 7/8] staging/rdma/hfi1: Reduce snoop locking scope in IOCTL handler.

Thanks for the report,
Ira

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