[PATCH] [24/50] x86_64: Eliminate result signage problem in asm-x86_64/bitops.h

[Andi Kleen]

From: Chuck Lever <chuck.lever@xxxxxxxxxx>
The return type of __scanbit() doesn't match the return type of
find_{first,next}_bit().  Thus when you construct something like
this:

   boolean ? __scanbit() : find_first_bit()

you get an unsigned long result if "boolean" is true, and a signed
long result if "boolean" is false.

In file included from /home/cel/src/linux/include/linux/mmzone.h:15,
                 from /home/cel/src/linux/include/linux/gfp.h:4,
                 from /home/cel/src/linux/include/linux/slab.h:14,
                 from /home/cel/src/linux/include/linux/percpu.h:5,
                 from
/home/cel/src/linux/include/linux/rcupdate.h:41,
                 from /home/cel/src/linux/include/linux/dcache.h:10,
                 from /home/cel/src/linux/include/linux/fs.h:275,
                 from /home/cel/src/linux/fs/nfs/sysctl.c:9:
/home/cel/src/linux/include/linux/nodemask.h: In function
â??__first_nodeâ??:
/home/cel/src/linux/include/linux/nodemask.h:229: warning: signed and
unsigned type in conditional expression
/home/cel/src/linux/include/linux/nodemask.h: In function
â??__next_nodeâ??:
/home/cel/src/linux/include/linux/nodemask.h:235: warning: signed and
unsigned type in conditional expression
/home/cel/src/linux/include/linux/nodemask.h: In function
â??__first_unset_nodeâ??:
/home/cel/src/linux/include/linux/nodemask.h:253: warning: signed and
unsigned type in conditional expression

Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxx>

---

 include/asm-x86_64/bitops.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux/include/asm-x86_64/bitops.h
===================================================================
--- linux.orig/include/asm-x86_64/bitops.h
+++ linux/include/asm-x86_64/bitops.h
@@ -260,7 +260,7 @@ extern long find_first_bit(const unsigne
 extern long find_next_bit(const unsigned long * addr, long size, long offset);
 
 /* return index of first bet set in val or max when no bit is set */
-static inline unsigned long __scanbit(unsigned long val, unsigned long max)
+static inline long __scanbit(unsigned long val, unsigned long max)
 {
 	asm("bsfq %1,%0 ; cmovz %2,%0" : "=&r" (val) : "r" (val), "r" (max));
 	return val;
-
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