linux/include/asm-x86_64/bug.h
Jan Beulich 049cdefe19 [PATCH] x86-64: reduce x86-64 bug frame by 4 bytes
As mentioned before, the size of the bug frame can be further reduced while
continuing to use instructions to encode the information.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-12 10:50:58 -07:00

35 lines
847 B
C

#ifndef __ASM_X8664_BUG_H
#define __ASM_X8664_BUG_H 1
#include <linux/stringify.h>
/*
* Tell the user there is some problem. The exception handler decodes
* this frame.
*/
struct bug_frame {
unsigned char ud2[2];
unsigned char push;
signed int filename;
unsigned char ret;
unsigned short line;
} __attribute__((packed));
#ifdef CONFIG_BUG
#define HAVE_ARCH_BUG
/* We turn the bug frame into valid instructions to not confuse
the disassembler. Thanks to Jan Beulich & Suresh Siddha
for nice instruction selection.
The magic numbers generate mov $64bitimm,%eax ; ret $offset. */
#define BUG() \
asm volatile( \
"ud2 ; pushq $%c1 ; ret $%c0" :: \
"i"(__LINE__), "i" (__FILE__))
void out_of_line_bug(void);
#else
static inline void out_of_line_bug(void) { }
#endif
#include <asm-generic/bug.h>
#endif