android_kernel_motorola_sm6225/include/asm-generic/bug.h
Linus Torvalds 8d4fbcfbe0 Fix WARN_ON() on bitfield ops
Alexey Dobriyan noticed that the new WARN_ON() semantics that were
introduced by commit 684f978347 (to also
return the value to be warned on) didn't compile when given a bitfield,
because the typeof doesn't work for bitfields.

So instead of the typeof trick, use an "int" variable together with a
"!!(x)" expression, as suggested by Al Viro.

To make matters more interesting, Paul Mackerras points out that that is
sub-optimal on Power, but the old asm-coded comparison seems to be buggy
anyway on 32-bit Power if the conditional was 64-bit, so I think there
are more problems there.

Regardless, the new WARN_ON() semantics may have been a bad idea.  But
this at least avoids the more serious complications.

Cc: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-07-31 21:12:07 -07:00

79 lines
1.6 KiB
C

#ifndef _ASM_GENERIC_BUG_H
#define _ASM_GENERIC_BUG_H
#include <linux/compiler.h>
#ifdef CONFIG_BUG
#ifdef CONFIG_GENERIC_BUG
#ifndef __ASSEMBLY__
struct bug_entry {
unsigned long bug_addr;
#ifdef CONFIG_DEBUG_BUGVERBOSE
const char *file;
unsigned short line;
#endif
unsigned short flags;
};
#endif /* __ASSEMBLY__ */
#define BUGFLAG_WARNING (1<<0)
#endif /* CONFIG_GENERIC_BUG */
#ifndef HAVE_ARCH_BUG
#define BUG() do { \
printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __FUNCTION__); \
panic("BUG!"); \
} while (0)
#endif
#ifndef HAVE_ARCH_BUG_ON
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while(0)
#endif
#ifndef HAVE_ARCH_WARN_ON
#define WARN_ON(condition) ({ \
int __ret_warn_on = !!(condition); \
if (unlikely(__ret_warn_on)) { \
printk("WARNING: at %s:%d %s()\n", __FILE__, \
__LINE__, __FUNCTION__); \
dump_stack(); \
} \
unlikely(__ret_warn_on); \
})
#endif
#else /* !CONFIG_BUG */
#ifndef HAVE_ARCH_BUG
#define BUG()
#endif
#ifndef HAVE_ARCH_BUG_ON
#define BUG_ON(condition) do { if (condition) ; } while(0)
#endif
#ifndef HAVE_ARCH_WARN_ON
#define WARN_ON(condition) ({ \
int __ret_warn_on = !!(condition); \
unlikely(__ret_warn_on); \
})
#endif
#endif
#define WARN_ON_ONCE(condition) ({ \
static int __warned; \
int __ret_warn_once = !!(condition); \
\
if (unlikely(__ret_warn_once)) \
if (WARN_ON(!__warned)) \
__warned = 1; \
unlikely(__ret_warn_once); \
})
#ifdef CONFIG_SMP
# define WARN_ON_SMP(x) WARN_ON(x)
#else
# define WARN_ON_SMP(x) do { } while (0)
#endif
#endif