[PATCH][2.6] first/next_cpu returns values > NR_CPUS

[Zwane Mwaikambo]

The following caused some fireworks whilst merging i386 cpu hotplug.

any_online_cpu(0x2) returns 32 on i386 if we're forced to continue past
the only set bit due to the additional find_first_bit in the
find_next_bit i386 implementation. Not wanting to change current
behaviour in the bitops primitives and since the NR_CPUS thing is a
cpumask issue, i've opted to fix next_cpu() and first_cpu() instead.

Signed-off-by: Zwane Mwaikambo <zwane@xxxxxxxxxxx>

Index: linux-2.6.8-rc2-mm1-lch/include/linux/cpumask.h
===================================================================
RCS file: /home/cvsroot/linux-2.6.8-rc2-mm1/include/linux/cpumask.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 cpumask.h
--- linux-2.6.8-rc2-mm1-lch/include/linux/cpumask.h	28 Jul 2004 14:35:22 -0000	1.1.1.1
+++ linux-2.6.8-rc2-mm1-lch/include/linux/cpumask.h	31 Jul 2004 17:57:12 -0000
@@ -207,13 +207,19 @@ static inline void __cpus_shift_left(cpu
 #define first_cpu(src) __first_cpu(&(src), NR_CPUS)
 static inline int __first_cpu(const cpumask_t *srcp, int nbits)
 {
-	return find_first_bit(srcp->bits, nbits);
+	int cpu = find_first_bit(srcp->bits, nbits);
+	if (cpu > NR_CPUS)
+		cpu = NR_CPUS;
+	return cpu;
 }

 #define next_cpu(n, src) __next_cpu((n), &(src), NR_CPUS)
 static inline int __next_cpu(int n, const cpumask_t *srcp, int nbits)
 {
-	return find_next_bit(srcp->bits, nbits, n+1);
+	int cpu = find_next_bit(srcp->bits, nbits, n+1);
+	if (cpu > NR_CPUS)
+		cpu = NR_CPUS;
+	return cpu;
 }

 #define cpumask_of_cpu(cpu)						\
-
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