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

From: Chuck Lever
Date: Wed Aug 15 2007 - 17:11:31 EST


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>
---

include/asm-x86_64/bitops.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/include/asm-x86_64/bitops.h b/include/asm-x86_64/bitops.h
index d4dbbe5..1d7d9b4 100644
--- a/include/asm-x86_64/bitops.h
+++ b/include/asm-x86_64/bitops.h
@@ -260,7 +260,7 @@ extern long find_first_bit(const unsigned long * addr, unsigned long size);
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;

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/