include/asm-x86_64/bug.h

   1 #ifndef __ASM_X8664_BUG_H
   2 #define __ASM_X8664_BUG_H 1
   3
   4 #include <linux/stringify.h>
   5
   6 /*
   7  * Tell the user there is some problem.  The exception handler decodes
   8  * this frame.
   9  */
  10 struct bug_frame {
  11         unsigned char ud2[2];
  12         unsigned char mov;
  13         /* should use 32bit offset instead, but the assembler doesn't
  14            like it */
  15         char *filename;
  16         unsigned char ret;
  17         unsigned short line;
  18 } __attribute__((packed));
  19
  20 #ifdef CONFIG_BUG
  21 #define HAVE_ARCH_BUG
  22 /* We turn the bug frame into valid instructions to not confuse
  23    the disassembler. Thanks to Jan Beulich & Suresh Siddha
  24    for nice instruction selection.
  25    The magic numbers generate mov $64bitimm,%eax ; ret $offset. */
  26 #define BUG()                                                           \
  27         asm volatile(                                                   \
  28         "ud2 ; .byte 0xa3 ; .quad %c1 ; .byte 0xc2 ; .short %c0" ::     \
  29                      "i"(__LINE__), "i" (__stringify(__FILE__)))
  30 void out_of_line_bug(void);
  31 #else
  32 static inline void out_of_line_bug(void) { }
  33 #endif
  34
  35 #include <asm-generic/bug.h>
  36 #endif