3.2.51-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: David Vrabel <david.vra...@citrix.com>
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.vra...@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
drivers/xen/events.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -316,7 +316,7 @@ static void init_evtchn_cpu_bindings(voi
for_each_possible_cpu(i)
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)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
