From: Stephen Hemminger <stephen@networkplumber.org>
To: Stanislaw Gruszka <stf_xl@wp.pl>
Cc: netdev@vger.kernel.org, Mirko Lindner <mlindner@marvell.com>
Subject: Re: [PATCH] sky2: initialize napi before registering device
Date: Sat, 25 Jan 2014 17:01:20 -0800 [thread overview]
Message-ID: <20140125170120.2e78cdb4@nehalam.linuxnetplumber.net> (raw)
In-Reply-To: <20140125103454.GA2490@localhost.localdomain>
On Sat, 25 Jan 2014 11:34:54 +0100
Stanislaw Gruszka <stf_xl@wp.pl> wrote:
> There is race condition when call netif_napi_add() after
> register_netdevice(), as ->open() can be called without napi initialized
> and trigger BUG_ON() on napi_enable(), like on below messages:
>
> [ 9.699863] sky2: driver version 1.30
> [ 9.699960] sky2 0000:02:00.0: Yukon-2 EC Ultra chip revision 2
> [ 9.700020] sky2 0000:02:00.0: irq 45 for MSI/MSI-X
> [ 9.700498] ------------[ cut here ]------------
> [ 9.703391] kernel BUG at include/linux/netdevice.h:501!
> [ 9.703391] invalid opcode: 0000 [#1] PREEMPT SMP
> <snip>
> [ 9.830018] Call Trace:
> [ 9.830018] [<fa996169>] sky2_open+0x309/0x360 [sky2]
> [ 9.830018] [<c1007210>] ? via_no_dac+0x40/0x40
> [ 9.830018] [<c1007210>] ? via_no_dac+0x40/0x40
> [ 9.830018] [<c135ed4b>] __dev_open+0x9b/0x120
> [ 9.830018] [<c1431cbe>] ? _raw_spin_unlock_bh+0x1e/0x20
> [ 9.830018] [<c135efd9>] __dev_change_flags+0x89/0x150
> [ 9.830018] [<c135f148>] dev_change_flags+0x18/0x50
> [ 9.830018] [<c13bb8e0>] devinet_ioctl+0x5d0/0x6e0
> [ 9.830018] [<c13bcced>] inet_ioctl+0x6d/0xa0
>
> To fix the problem patch changes the order of initialization.
>
> Bug report:
> https://bugzilla.kernel.org/show_bug.cgi?id=67151
>
> Reported-and-tested-by: ebrahim.azarisooreh@gmail.com
> Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
That looks good, problem was introduced years ago.
I wonder if netif_napi_del() should be in unwind if registration
of either devices fails?
next prev parent reply other threads:[~2014-01-26 1:01 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-25 10:34 [PATCH] sky2: initialize napi before registering device Stanislaw Gruszka
2014-01-26 1:01 ` Stephen Hemminger [this message]
2014-01-27 11:53 ` Stanislaw Gruszka
2014-01-28 0:40 ` David Miller
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