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| author | Joe Jin <joe.jin@oracle.com> | 2011-01-07 18:17:17 +0800 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2011-01-10 10:46:30 -0500 |
| commit | 731f3ab66a23dab28a359e87364f53d221b3d366 (patch) | |
| tree | 6f744443ba56c75278a9c2196620b089ccfd0008 | |
| parent | c1f5db1a53a7286f6c818f71016ae6aced814d27 (diff) | |
| download | linux-731f3ab66a23dab28a359e87364f53d221b3d366.tar.gz linux-731f3ab66a23dab28a359e87364f53d221b3d366.tar.bz2 linux-731f3ab66a23dab28a359e87364f53d221b3d366.zip | |
xen/fb: fix xenfb suspend/resume race.
When migrating guests over a long period we hit this:
<1>BUG: unable to handle kernel paging request at 0000000b819fdb98
<1>IP: [<ffffffff812a588f>] notify_remote_via_irq+0x13/0x34
<4>PGD 94b10067 PUD 0
<0>Oops: 0000 [#1] SMP
.. snip..
Call Trace:
[<ffffffff812712c9>] xenfb_send_event+0x5c/0x5e
[<ffffffff8100ea5f>] ? xen_restore_fl_direct_end+0x0/0x1
[<ffffffff81438d80>] ? _spin_unlock_irqrestore+0x16/0x18
[<ffffffff812714ee>] xenfb_refresh+0x1b1/0x1d7
[<ffffffff81270568>] ? sys_imageblit+0x1ac/0x458
[<ffffffff81271786>] xenfb_imageblit+0x2f/0x34
[<ffffffff8126a3e5>] soft_cursor+0x1b5/0x1c8
[<ffffffff8126a137>] bit_cursor+0x4b6/0x4d7
[<ffffffff8100ea5f>] ? xen_restore_fl_direct_end+0x0/0x1
[<ffffffff81438d80>] ? _spin_unlock_irqrestore+0x16/0x18
[<ffffffff81269c81>] ? bit_cursor+0x0/0x4d7
[<ffffffff812656b7>] fb_flashcursor+0xff/0x111
[<ffffffff812655b8>] ? fb_flashcursor+0x0/0x111
[<ffffffff81071812>] worker_thread+0x14d/0x1ed
[<ffffffff81075a8c>] ? autoremove_wake_function+0x0/0x3d
[<ffffffff81438d80>] ? _spin_unlock_irqrestore+0x16/0x18
[<ffffffff810716c5>] ? worker_thread+0x0/0x1ed
[<ffffffff810756e3>] kthread+0x6e/0x76
[<ffffffff81012dea>] child_rip+0xa/0x20
[<ffffffff81011fd1>] ? int_ret_from_sys_call+0x7/0x1b
[<ffffffff8101275d>] ? retint_restore_args+0x5/0x6
[<ffffffff81012de0>] ? child_rip+0x0/0x20
Code: 6b ff 0c 8b 87 a4 db 9f 81 66 85 c0 74 08 0f b7 f8 e8 3b ff ff ff c9
c3 55 48 89 e5 48 83 ec 10 0f 1f 44 00 00 89 ff 48 6b ff 0c <8b> 87 a4 db 9f
81 66 85 c0 74 14 48 8d 75 f0 0f b7 c0 bf 04 00
RIP [<ffffffff812a588f>] notify_remote_via_irq+0x13/0x34
RSP <ffff8800e7bf7bd0>
CR2: 0000000b819fdb98
---[ end trace 098b4b74827595d0 ]---
The root cause of the panic is the race between the resume and reconnect to the backend.
Clearing the 'update_wanted' flag of xenfb before disconnecting from the
backend fixes this issue.
Signed-off-by: Joe Jin <joe.jin@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Gurudas Pai <gurudas.pai@oracle.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | drivers/video/xen-fbfront.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/video/xen-fbfront.c b/drivers/video/xen-fbfront.c index 428d273be727..f92313d33e27 100644 --- a/drivers/video/xen-fbfront.c +++ b/drivers/video/xen-fbfront.c @@ -617,6 +617,8 @@ static int xenfb_connect_backend(struct xenbus_device *dev, static void xenfb_disconnect_backend(struct xenfb_info *info) { + /* Prevent xenfb refresh */ + info->update_wanted = 0; if (info->irq >= 0) unbind_from_irqhandler(info->irq, info); info->irq = -1; |