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author | Amit Shah <amit.shah@redhat.com> | 2013-03-29 11:00:08 (GMT) |
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committer | Rusty Russell <rusty@rustcorp.com.au> | 2013-03-30 03:55:46 (GMT) |
commit | 9ba5c80b1aea8648a3efe5f22dc1f7cacdfbeeb8 (patch) | |
tree | cdb191b7987323a4e454c9033ba4e449483ad57d /fs | |
parent | 165b1b8bbc17c9469b053bab78b11b7cbce6d161 (diff) | |
download | linux-9ba5c80b1aea8648a3efe5f22dc1f7cacdfbeeb8.tar.xz |
virtio: console: add locking around c_ovq operations
When multiple ovq operations are being performed (lots of open/close
operations on virtio_console fds), the __send_control_msg() function can
get confused without locking.
A simple recipe to cause badness is:
* create a QEMU VM with two virtio-serial ports
* in the guest, do
while true;do echo abc >/dev/vport0p1;done
while true;do echo edf >/dev/vport0p2;done
In one run, this caused a panic in __send_control_msg(). In another, I
got
virtio_console virtio0: control-o:id 0 is not a head!
This also results repeated messages similar to these on the host:
qemu-kvm: virtio-serial-bus: Unexpected port id 478762112 for device virtio-serial-bus.0
qemu-kvm: virtio-serial-bus: Unexpected port id 478762368 for device virtio-serial-bus.0
Reported-by: FuXiangChun <xfu@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Reviewed-by: Asias He <asias@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
Diffstat (limited to 'fs')
0 files changed, 0 insertions, 0 deletions