Messages in this thread Patch in this message | | | Subject | [PATCH v3 1/3] virtio_console: Fix locking of vtermno. | From | Miche Baker-Harvey <> | Date | Tue, 08 Nov 2011 13:44:58 -0800 |
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Some modifications of vtermno were not done under the spinlock.
Moved assignment from vtermno and increment of vtermno together, putting both under the spinlock. Revert vtermno on failure.
Signed-off-by: Miche Baker-Harvey <miche@google.com> --- drivers/char/virtio_console.c | 9 ++++++--- 1 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 8e3c46d..9722e76 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -987,18 +987,21 @@ int init_port_console(struct port *port) * pointers. The final argument is the output buffer size: we * can do any size, so we put PAGE_SIZE here. */ - port->cons.vtermno = pdrvdata.next_vtermno; + spin_lock_irq(&pdrvdata_lock); + port->cons.vtermno = pdrvdata.next_vtermno++; + spin_unlock_irq(&pdrvdata_lock); port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE); + spin_lock_irq(&pdrvdata_lock); if (IS_ERR(port->cons.hvc)) { ret = PTR_ERR(port->cons.hvc); dev_err(port->dev, "error %d allocating hvc for port\n", ret); port->cons.hvc = NULL; + port->cons.vtermno = pdrvdata.next_vtermno--; + spin_unlock_irq(&pdrvdata_lock); return ret; } - spin_lock_irq(&pdrvdata_lock); - pdrvdata.next_vtermno++; list_add_tail(&port->cons.list, &pdrvdata.consoles); spin_unlock_irq(&pdrvdata_lock); port->guest_connected = true;
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