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authorDavid Vrabel <david.vrabel@citrix.com>2013-08-15 13:21:06 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-08-29 09:42:12 -0700
commit1b9ba06c5f4e84b8dfa402bee0daff42db045977 (patch)
parent50e27a160f6146de036e81420dc13ec9f4824564 (diff)
xen/events: initialize local per-cpu mask for all possible events
commit 84ca7a8e45dafb49cd5ca90a343ba033e2885c17 upstream. The sizeof() argument in init_evtchn_cpu_bindings() is incorrect resulting in only the first 64 (or 32 in 32-bit guests) ports having their bindings being initialized to VCPU 0. In most cases this does not cause a problem as request_irq() will set the irq affinity which will set the correct local per-cpu mask. However, if the request_irq() is called on a VCPU other than 0, there is a window between the unmasking of the event and the affinity being set were an event may be lost because it is not locally unmasked on any VCPU. If request_irq() is called on VCPU 0 then local irqs are disabled during the window and the race does not occur. Fix this by initializing all NR_EVENT_CHANNEL bits in the local per-cpu masks. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index a2f1f71fde15..7ba4d0e8f2b6 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -317,7 +317,7 @@ static void init_evtchn_cpu_bindings(void)
memset(per_cpu(cpu_evtchn_mask, i),
- (i == 0) ? ~0 : 0, sizeof(*per_cpu(cpu_evtchn_mask, i)));
+ (i == 0) ? ~0 : 0, NR_EVENT_CHANNELS/8);
static inline void clear_evtchn(int port)