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| author | David Vrabel <david.vrabel@citrix.com> | 2013-08-15 14:21:06 +0200 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-08-20 16:13:02 +0200 |
| commit | 84ca7a8e45dafb49cd5ca90a343ba033e2885c17 (patch) | |
| tree | 78e6c4f1baed53a9e431125e486cd036a4490a91 /drivers/xen | |
| parent | x86/xen: do not identity map UNUSABLE regions in the machine E820 (diff) | |
| download | linux-84ca7a8e45dafb49cd5ca90a343ba033e2885c17.tar.xz linux-84ca7a8e45dafb49cd5ca90a343ba033e2885c17.zip | |
xen/events: initialize local per-cpu mask for all possible events
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>
CC: stable@vger.kernel.org
Diffstat (limited to 'drivers/xen')
| -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 a58ac435a9a4..a1ad5dae8ee1 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -348,7 +348,7 @@ 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) |