arch/powerpc/include/asm/bug.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_POWERPC_BUG_H
   3 #define _ASM_POWERPC_BUG_H
   4 #ifdef __KERNEL__
   5
   6 #include <asm/asm-compat.h>
   7
   8 /*
   9  * Define an illegal instr to trap on the bug.
  10  * We don't use 0 because that marks the end of a function
  11  * in the ELF ABI.  That's "Boo Boo" in case you wonder...
  12  */
  13 #define BUG_OPCODE .long 0x00b00b00  /* For asm */
  14 #define BUG_ILLEGAL_INSTR "0x00b00b00" /* For BUG macro */
  15
  16 #ifdef CONFIG_BUG
  17
  18 #ifdef __ASSEMBLY__
  19 #include <asm/asm-offsets.h>
  20 #ifdef CONFIG_DEBUG_BUGVERBOSE
  21 .macro EMIT_BUG_ENTRY addr,file,line,flags
  22          .section __bug_table,"aw"
  23 5001:    PPC_LONG \addr, 5002f
  24          .short \line, \flags
  25          .org 5001b+BUG_ENTRY_SIZE
  26          .previous
  27          .section .rodata,"a"
  28 5002:    .asciz "\file"
  29          .previous
  30 .endm
  31 #else
  32 .macro EMIT_BUG_ENTRY addr,file,line,flags
  33          .section __bug_table,"aw"
  34 5001:    PPC_LONG \addr
  35          .short \flags
  36          .org 5001b+BUG_ENTRY_SIZE
  37          .previous
  38 .endm
  39 #endif /* verbose */
  40
  41 #else /* !__ASSEMBLY__ */
  42 /* _EMIT_BUG_ENTRY expects args %0,%1,%2,%3 to be FILE, LINE, flags and
  43    sizeof(struct bug_entry), respectively */
  44 #ifdef CONFIG_DEBUG_BUGVERBOSE
  45 #define _EMIT_BUG_ENTRY                         \
  46         ".section __bug_table,\"aw\"\n"         \
  47         "2:\t" PPC_LONG "1b, %0\n"              \
  48         "\t.short %1, %2\n"                     \
  49         ".org 2b+%3\n"                          \
  50         ".previous\n"
  51 #else
  52 #define _EMIT_BUG_ENTRY                         \
  53         ".section __bug_table,\"aw\"\n"         \
  54         "2:\t" PPC_LONG "1b\n"                  \
  55         "\t.short %2\n"                         \
  56         ".org 2b+%3\n"                          \
  57         ".previous\n"
  58 #endif
  59
  60 /*
  61  * BUG_ON() and WARN_ON() do their best to cooperate with compile-time
  62  * optimisations. However depending on the complexity of the condition
  63  * some compiler versions may not produce optimal results.
  64  */
  65
  66 #define BUG() do {                                              \
  67         __asm__ __volatile__(                                   \
  68                 "1:     twi 31,0,0\n"                           \
  69                 _EMIT_BUG_ENTRY                                 \
  70                 : : "i" (__FILE__), "i" (__LINE__),             \
  71                     "i" (0), "i"  (sizeof(struct bug_entry)));  \
  72         unreachable();                                          \
  73 } while (0)
  74
  75 #define BUG_ON(x) do {                                          \
  76         if (__builtin_constant_p(x)) {                          \
  77                 if (x)                                          \
  78                         BUG();                                  \
  79         } else {                                                \
  80                 __asm__ __volatile__(                           \
  81                 "1:     "PPC_TLNEI"     %4,0\n"                 \
  82                 _EMIT_BUG_ENTRY                                 \
  83                 : : "i" (__FILE__), "i" (__LINE__), "i" (0),    \
  84                   "i" (sizeof(struct bug_entry)),               \
  85                   "r" ((__force long)(x)));                     \
  86         }                                                       \
  87 } while (0)
  88
  89 #define __WARN_FLAGS(flags) do {                                \
  90         __asm__ __volatile__(                                   \
  91                 "1:     twi 31,0,0\n"                           \
  92                 _EMIT_BUG_ENTRY                                 \
  93                 : : "i" (__FILE__), "i" (__LINE__),             \
  94                   "i" (BUGFLAG_WARNING|(flags)),                \
  95                   "i" (sizeof(struct bug_entry)));              \
  96 } while (0)
  97
  98 #define WARN_ON(x) ({                                           \
  99         int __ret_warn_on = !!(x);                              \
 100         if (__builtin_constant_p(__ret_warn_on)) {              \
 101                 if (__ret_warn_on)                              \
 102                         __WARN();                               \
 103         } else {                                                \
 104                 __asm__ __volatile__(                           \
 105                 "1:     "PPC_TLNEI"     %4,0\n"                 \
 106                 _EMIT_BUG_ENTRY                                 \
 107                 : : "i" (__FILE__), "i" (__LINE__),             \
 108                   "i" (BUGFLAG_WARNING|BUGFLAG_TAINT(TAINT_WARN)),\
 109                   "i" (sizeof(struct bug_entry)),               \
 110                   "r" (__ret_warn_on));                         \
 111         }                                                       \
 112         unlikely(__ret_warn_on);                                \
 113 })
 114
 115 #define HAVE_ARCH_BUG
 116 #define HAVE_ARCH_BUG_ON
 117 #define HAVE_ARCH_WARN_ON
 118 #endif /* __ASSEMBLY __ */
 119 #else
 120 #ifdef __ASSEMBLY__
 121 .macro EMIT_BUG_ENTRY addr,file,line,flags
 122 .endm
 123 #else /* !__ASSEMBLY__ */
 124 #define _EMIT_BUG_ENTRY
 125 #endif
 126 #endif /* CONFIG_BUG */
 127
 128 #include <asm-generic/bug.h>
 129
 130 #ifndef __ASSEMBLY__
 131
 132 struct pt_regs;
 133 extern int do_page_fault(struct pt_regs *, unsigned long, unsigned long);
 134 extern void bad_page_fault(struct pt_regs *, unsigned long, int);
 135 extern void _exception(int, struct pt_regs *, int, unsigned long);
 136 extern void die(const char *, struct pt_regs *, long);
 137 extern bool die_will_crash(void);
 138
 139 #endif /* !__ASSEMBLY__ */
 140
 141 #endif /* __KERNEL__ */
 142 #endif /* _ASM_POWERPC_BUG_H */