x86: fix cpu_mask_to_apicid_and to include cpu_online_mask

Impact: fix potential APIC crash

In determining the destination apicid, there are usually three cpumasks
that are considered: the incoming cpumask arg, cfg->domain and the
cpu_online_mask.  Since we are just introducing the cpu_mask_to_apicid_and
function, make sure it includes the cpu_online_mask in it's evaluation.
[Added with this patch.]

There are two io_apic.c functions that did not previously use the
cpu_online_mask:  setup_IO_APIC_irq and msi_compose_msg.  Both of these
simply used cpu_mask_to_apicid(cfg->domain & TARGET_CPUS), and all but
one arch (NUMAQ[*]) returns only online cpus in the TARGET_CPUS mask,
so the behavior is identical for all cases.

[*: NUMAQ bug?]

Note that alloc_cpumask_var is only used for the 32-bit cases where
it's highly likely that the cpumask set size will be small and therefore
CPUMASK_OFFSTACK=n.  But if that's not the case, failing the allocate
will cause the same return value as the default.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/x86/include/asm/mach-default/mach_apic.h b/arch/x86/include/asm/mach-default/mach_apic.h
index 8863d978cb96..cc09cbbee27e 100644
--- a/arch/x86/include/asm/mach-default/mach_apic.h
+++ b/arch/x86/include/asm/mach-default/mach_apic.h
@@ -72,8 +72,9 @@ static inline unsigned int cpu_mask_to_apicid_and(const struct cpumask *cpumask,
 {
         unsigned long mask1 = cpumask_bits(cpumask)[0];
         unsigned long mask2 = cpumask_bits(andmask)[0];
+        unsigned long mask3 = cpumask_bits(cpu_online_mask)[0];
 
-        return (unsigned int)(mask1 & mask2);
+        return (unsigned int)(mask1 & mask2 & mask3);
 }
 
 static inline u32 phys_pkg_id(u32 cpuid_apic, int index_msb)