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| author | David Vrabel <david.vrabel@citrix.com> | 2013-08-15 16:21:06 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-08-29 20:50:12 +0400 |
| commit | a34794460aa1fb5096708d079a29606123a2ec9c (patch) | |
| tree | b96f448c8aa495352031509e7e01bbade77f8dee | |
| parent | 523578f790ece2db130b23e8d2ef37e48f698317 (diff) | |
| download | linux-a34794460aa1fb5096708d079a29606123a2ec9c.tar.xz | |
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>
| -rw-r--r-- | drivers/xen/events.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/xen/events.c b/drivers/xen/events.c index 417c1333f6c0..33dcad6371f5 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -324,7 +324,7 @@ static void init_evtchn_cpu_bindings(void) 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) |