linux/arch/x86/include/asm/bug.h
Josh Triplett b06dd879f5 x86: always define BUG() and HAVE_ARCH_BUG, even with !CONFIG_BUG
This ensures that BUG() always has a definition that causes a trap (via
an undefined instruction), and that the compiler still recognizes the
code following BUG() as unreachable, avoiding warnings that would
otherwise appear (such as on non-void functions that don't return a
value after BUG()).

In addition to saving a few bytes over the generic infinite-loop
implementation, this implementation traps rather than looping, which
potentially allows for better error-recovery behavior (such as by
rebooting).

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:10 -07:00

38 lines
743 B
C

#ifndef _ASM_X86_BUG_H
#define _ASM_X86_BUG_H
#define HAVE_ARCH_BUG
#ifdef CONFIG_DEBUG_BUGVERBOSE
#ifdef CONFIG_X86_32
# define __BUG_C0 "2:\t.long 1b, %c0\n"
#else
# define __BUG_C0 "2:\t.long 1b - 2b, %c0 - 2b\n"
#endif
#define BUG() \
do { \
asm volatile("1:\tud2\n" \
".pushsection __bug_table,\"a\"\n" \
__BUG_C0 \
"\t.word %c1, 0\n" \
"\t.org 2b+%c2\n" \
".popsection" \
: : "i" (__FILE__), "i" (__LINE__), \
"i" (sizeof(struct bug_entry))); \
unreachable(); \
} while (0)
#else
#define BUG() \
do { \
asm volatile("ud2"); \
unreachable(); \
} while (0)
#endif
#include <asm-generic/bug.h>
#endif /* _ASM_X86_BUG_H */