Re: [bisected] kernel panic 2.6.22 -> 2.6.26-rc9+

On Sun, 13 Jul 2008 23:51:06 +0200 Krzysztof Halasa [off-list ref] wrote:

Andrew Morton [off-list ref] writes:

quoted

--- a/include/asm-arm/bitops.h~a
+++ a/include/asm-arm/bitops.h

@@ -277,9 +277,16 @@ static inline int constant_fls(int x)
  * the clz instruction for much better code efficiency.
  */
 
-#define fls(x) \
+#define __fls(x) \
 	( __builtin_constant_p(x) ? constant_fls(x) : \
 	  ({ int __r; asm("clz\t%0, %1" : "=r"(__r) : "r"(x) : "cc"); 32-__r; }) )
+
+/* Implement fls() in C so that 64-bit args are suitably truncated */
+static inline int fls(int x)
+{
+	return __fls(x);
+}
+

Well, I like it more as it fixes all possible places instead of only
fls64().

But... can't we just move the #define body into the inline fls(x)?
Will there be other users of __fls(x)? It seems the
__builtin_constant_p(x) works for inline functions.

Could.  That was a minimal&safe thing.

The above patch fixes the kernel panic, too.

OK, thanks.