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| author | David Vrabel <david.vrabel@citrix.com> | 2015-05-19 18:40:49 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-06-06 08:20:52 -0700 |
| commit | a4b513b2a434a02381f2c981a3aba6ecb000118e (patch) | |
| tree | 6bf061471cb53c5af1f695823ed3800cea838e66 /drivers/tty | |
| parent | 68482f12d90fb757eef19493fb7bf7fdc1029a7a (diff) | |
| download | lwn-a4b513b2a434a02381f2c981a3aba6ecb000118e.tar.gz lwn-a4b513b2a434a02381f2c981a3aba6ecb000118e.zip | |
xen/events: don't bind non-percpu VIRQs with percpu chip
commit 77bb3dfdc0d554befad58fdefbc41be5bc3ed38a upstream.
A non-percpu VIRQ (e.g., VIRQ_CONSOLE) may be freed on a different
VCPU than it is bound to. This can result in a race between
handle_percpu_irq() and removing the action in __free_irq() because
handle_percpu_irq() does not take desc->lock. The interrupt handler
sees a NULL action and oopses.
Only use the percpu chip/handler for per-CPU VIRQs (like VIRQ_TIMER).
# cat /proc/interrupts | grep virq
40: 87246 0 xen-percpu-virq timer0
44: 0 0 xen-percpu-virq debug0
47: 0 20995 xen-percpu-virq timer1
51: 0 0 xen-percpu-virq debug1
69: 0 0 xen-dyn-virq xen-pcpu
74: 0 0 xen-dyn-virq mce
75: 29 0 xen-dyn-virq hvc_console
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/hvc/hvc_xen.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c index 5bab1c684bb1..7a3d146a5f0e 100644 --- a/drivers/tty/hvc/hvc_xen.c +++ b/drivers/tty/hvc/hvc_xen.c @@ -289,7 +289,7 @@ static int xen_initial_domain_console_init(void) return -ENOMEM; } - info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0); + info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0, false); info->vtermno = HVC_COOKIE; spin_lock(&xencons_lock); |