arch/cris/include/arch-v10/arch/bug.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __ASM_CRISv10_ARCH_BUG_H
   3 #define __ASM_CRISv10_ARCH_BUG_H
   4
   5 #include <linux/stringify.h>
   6
   7 #ifdef CONFIG_BUG
   8 #ifdef CONFIG_DEBUG_BUGVERBOSE
   9 /* The BUG() macro is used for marking obviously incorrect code paths.
  10  * It will cause a message with the file name and line number to be printed,
  11  * and then cause an oops.  The message is actually printed by handle_BUG()
  12  * in arch/cris/kernel/traps.c, and the reason we use this method of storing
  13  * the file name and line number is that we do not want to affect the registers
  14  * by calling printk() before causing the oops.
  15  */
  16
  17 #define BUG_PREFIX 0x0D7F
  18 #define BUG_MAGIC  0x00001234
  19
  20 struct bug_frame {
  21         unsigned short prefix;
  22         unsigned int magic;
  23         unsigned short clear;
  24         unsigned short movu;
  25         unsigned short line;
  26         unsigned short jump;
  27         unsigned char *filename;
  28 };
  29
  30 #if 0
  31 /* Unfortunately this version of the macro does not work due to a problem
  32  * with the compiler (aka a bug) when compiling with -O2, which sometimes
  33  * erroneously causes the second input to be stored in a register...
  34  */
  35 #define BUG()                                                           \
  36         __asm__ __volatile__ ("clear.d [" __stringify(BUG_MAGIC) "]\n\t"\
  37                                 "movu.w %0,$r0\n\t"                     \
  38                                 "jump %1\n\t"                           \
  39                                 : : "i" (__LINE__), "i" (__FILE__))
  40 #else
  41 /* This version will have to do for now, until the compiler is fixed.
  42  * The drawbacks of this version are that the file name will appear multiple
  43  * times in the .rodata section, and that __LINE__ and __FILE__ can probably
  44  * not be used like this with newer versions of gcc.
  45  */
  46 #define BUG()                                                           \
  47 do {                                                                    \
  48         __asm__ __volatile__ ("clear.d [" __stringify(BUG_MAGIC) "]\n\t"\
  49                               "movu.w " __stringify(__LINE__) ",$r0\n\t"\
  50                               "jump 0f\n\t"                             \
  51                               ".section .rodata\n"                      \
  52                               "0:\t.string \"" __FILE__ "\"\n\t"        \
  53                               ".previous");                             \
  54         unreachable();                                                  \
  55 } while (0)
  56 #endif
  57
  58 #else
  59
  60 /* This just causes an oops. */
  61 #define BUG()                                                           \
  62 do {                                                                    \
  63         barrier_before_unreachable();                                   \
  64         __builtin_trap();                                               \
  65 } while (0)
  66
  67 #endif
  68
  69 #define HAVE_ARCH_BUG
  70 #endif
  71
  72 #include <asm-generic/bug.h>
  73
  74 #endif