Re: [GIT PULL -tip v3] fix 39 'make headers_check' warnings

Ingo Molnar
2009-01-18T18:51:17Z

hm, i just noticed this detail:

commit 3521c5eef990515719614e212b26ea49e610d072
Author: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Date: Sat Jan 17 19:25:46 2009 +0530

headers_check fix: x86, swab.h

fix the following 'make headers_check' warnings:

usr/include/asm/swab.h:4: include of <linux/types.h> is preferred over <asm/types.h>
usr/include/asm/swab.h:7: found __[us]{8,16,32,64} type without #include <linux/types.h>
usr/include/asm/swab.h:10: leaks CONFIG_X86 to userspace where it is not valid
usr/include/asm/swab.h:40: leaks CONFIG_X86 to userspace where it is not valid

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/include/asm/swab.h b/arch/x86/include/asm/swab.h
index 306d417..613be68 100644
--- a/arch/x86/include/asm/swab.h
+++ b/arch/x86/include/asm/swab.h
@@ -1,12 +1,15 @@
#ifndef _ASM_X86_SWAB_H
#define _ASM_X86_SWAB_H

-#include <asm/types.h>
+#include <linux/types.h>
+#ifdef __KERNEL__
#include <linux/compiler.h>
+#endif /* __KERNEL__ */

static inline __attribute_const__ __u32 __arch_swab32(__u32 val)
{
#ifdef __i386__
+#ifdef __KERNEL__
# ifdef CONFIG_X86_BSWAP
asm("bswap %0" : "=r" (val) : "0" (val));
# else
@@ -16,7 +19,13 @@ static inline __attribute_const__ __u32 __arch_swab32(__u32 val)
: "=q" (val)
: "0" (val));
# endif
-
+#else /* __KERNEL__ */
+ asm("xchgb %b0,%h0\n\t" /* swap lower bytes */
+ "rorl $16,%0\n\t" /* swap words */
+ "xchgb %b0,%h0" /* swap higher bytes */
+ : "=q" (val)
+ : "0" (val));
+#endif /* __KERNEL__ */
#else /* __i386__ */
asm("bswapl %0"
: "=r" (val)
@@ -37,6 +46,7 @@ static inline __attribute_const__ __u64 __arch_swab64(__u64 val)
__u64 u;
} v;
v.u = val;
+#ifdef __KERNEL__
# ifdef CONFIG_X86_BSWAP
asm("bswapl %0 ; bswapl %1 ; xchgl %0,%1"
: "=r" (v.s.a), "=r" (v.s.b)
@@ -48,6 +58,13 @@ static inline __attribute_const__ __u64 __arch_swab64(__u64 val)
: "=r" (v.s.a), "=r" (v.s.b)
: "0" (v.s.a), "1" (v.s.b));
# endif
+#else /* __KERNEL__ */
+ v.s.a = __arch_swab32(v.s.a);
+ v.s.b = __arch_swab32(v.s.b);
+ asm("xchgl %0,%1"
+ : "=r" (v.s.a), "=r" (v.s.b)
+ : "0" (v.s.a), "1" (v.s.b));
+#endif /* __KERNEL__ */
return v.u;
#else /* __i386__ */
asm("bswapq %0"

why does such a change introduce new code? It is duplicating existing code
instead of cleaning it all up.

Ingo