include/asm-generic/bug.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_GENERIC_BUG_H
   3 #define _ASM_GENERIC_BUG_H
   4
   5 #include <linux/compiler.h>
   6
   7 #ifdef CONFIG_GENERIC_BUG
   8 #define BUGFLAG_WARNING         (1 << 0)
   9 #define BUGFLAG_ONCE            (1 << 1)
  10 #define BUGFLAG_DONE            (1 << 2)
  11 #define BUGFLAG_TAINT(taint)    ((taint) << 8)
  12 #define BUG_GET_TAINT(bug)      ((bug)->flags >> 8)
  13 #endif
  14
  15 #ifndef __ASSEMBLY__
  16 #include <linux/kernel.h>
  17
  18 #ifdef CONFIG_BUG
  19
  20 #ifdef CONFIG_GENERIC_BUG
  21 struct bug_entry {
  22 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  23         unsigned long   bug_addr;
  24 #else
  25         signed int      bug_addr_disp;
  26 #endif
  27 #ifdef CONFIG_DEBUG_BUGVERBOSE
  28 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  29         const char      *file;
  30 #else
  31         signed int      file_disp;
  32 #endif
  33         unsigned short  line;
  34 #endif
  35         unsigned short  flags;
  36 };
  37 #endif  /* CONFIG_GENERIC_BUG */
  38
  39 /*
  40  * Don't use BUG() or BUG_ON() unless there's really no way out; one
  41  * example might be detecting data structure corruption in the middle
  42  * of an operation that can't be backed out of.  If the (sub)system
  43  * can somehow continue operating, perhaps with reduced functionality,
  44  * it's probably not BUG-worthy.
  45  *
  46  * If you're tempted to BUG(), think again:  is completely giving up
  47  * really the *only* solution?  There are usually better options, where
  48  * users don't need to reboot ASAP and can mostly shut down cleanly.
  49  */
  50 #ifndef HAVE_ARCH_BUG
  51 #define BUG() do { \
  52         printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
  53         panic("BUG!"); \
  54 } while (0)
  55 #endif
  56
  57 #ifndef HAVE_ARCH_BUG_ON
  58 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
  59 #endif
  60
  61 #ifdef __WARN_FLAGS
  62 #define __WARN_TAINT(taint)             __WARN_FLAGS(BUGFLAG_TAINT(taint))
  63 #define __WARN_ONCE_TAINT(taint)        __WARN_FLAGS(BUGFLAG_ONCE|BUGFLAG_TAINT(taint))
  64
  65 #define WARN_ON_ONCE(condition) ({                              \
  66         int __ret_warn_on = !!(condition);                      \
  67         if (unlikely(__ret_warn_on))                            \
  68                 __WARN_ONCE_TAINT(TAINT_WARN);                  \
  69         unlikely(__ret_warn_on);                                \
  70 })
  71 #endif
  72
  73 /*
  74  * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
  75  * significant issues that need prompt attention if they should ever
  76  * appear at runtime.  Use the versions with printk format strings
  77  * to provide better diagnostics.
  78  */
  79 #ifndef __WARN_TAINT
  80 extern __printf(3, 4)
  81 void warn_slowpath_fmt(const char *file, const int line,
  82                        const char *fmt, ...);
  83 extern __printf(4, 5)
  84 void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
  85                              const char *fmt, ...);
  86 extern void warn_slowpath_null(const char *file, const int line);
  87 #define WANT_WARN_ON_SLOWPATH
  88 #define __WARN()                warn_slowpath_null(__FILE__, __LINE__)
  89 #define __WARN_printf(arg...)   warn_slowpath_fmt(__FILE__, __LINE__, arg)
  90 #define __WARN_printf_taint(taint, arg...)                              \
  91         warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
  92 #else
  93 #define __WARN()                __WARN_TAINT(TAINT_WARN)
  94 #define __WARN_printf(arg...)   do { printk(arg); __WARN(); } while (0)
  95 #define __WARN_printf_taint(taint, arg...)                              \
  96         do { printk(arg); __WARN_TAINT(taint); } while (0)
  97 #endif
  98
  99 /* used internally by panic.c */
 100 struct warn_args;
 101 struct pt_regs;
 102
 103 void __warn(const char *file, int line, void *caller, unsigned taint,
 104             struct pt_regs *regs, struct warn_args *args);
 105
 106 #ifndef WARN_ON
 107 #define WARN_ON(condition) ({                                           \
 108         int __ret_warn_on = !!(condition);                              \
 109         if (unlikely(__ret_warn_on))                                    \
 110                 __WARN();                                               \
 111         unlikely(__ret_warn_on);                                        \
 112 })
 113 #endif
 114
 115 #ifndef WARN
 116 #define WARN(condition, format...) ({                                   \
 117         int __ret_warn_on = !!(condition);                              \
 118         if (unlikely(__ret_warn_on))                                    \
 119                 __WARN_printf(format);                                  \
 120         unlikely(__ret_warn_on);                                        \
 121 })
 122 #endif
 123
 124 #define WARN_TAINT(condition, taint, format...) ({                      \
 125         int __ret_warn_on = !!(condition);                              \
 126         if (unlikely(__ret_warn_on))                                    \
 127                 __WARN_printf_taint(taint, format);                     \
 128         unlikely(__ret_warn_on);                                        \
 129 })
 130
 131 #ifndef WARN_ON_ONCE
 132 #define WARN_ON_ONCE(condition) ({                              \
 133         static bool __section(.data.unlikely) __warned;         \
 134         int __ret_warn_once = !!(condition);                    \
 135                                                                 \
 136         if (unlikely(__ret_warn_once && !__warned)) {           \
 137                 __warned = true;                                \
 138                 WARN_ON(1);                                     \
 139         }                                                       \
 140         unlikely(__ret_warn_once);                              \
 141 })
 142 #endif
 143
 144 #define WARN_ONCE(condition, format...) ({                      \
 145         static bool __section(.data.unlikely) __warned;         \
 146         int __ret_warn_once = !!(condition);                    \
 147                                                                 \
 148         if (unlikely(__ret_warn_once && !__warned)) {           \
 149                 __warned = true;                                \
 150                 WARN(1, format);                                \
 151         }                                                       \
 152         unlikely(__ret_warn_once);                              \
 153 })
 154
 155 #define WARN_TAINT_ONCE(condition, taint, format...)    ({      \
 156         static bool __section(.data.unlikely) __warned;         \
 157         int __ret_warn_once = !!(condition);                    \
 158                                                                 \
 159         if (unlikely(__ret_warn_once && !__warned)) {           \
 160                 __warned = true;                                \
 161                 WARN_TAINT(1, taint, format);                   \
 162         }                                                       \
 163         unlikely(__ret_warn_once);                              \
 164 })
 165
 166 #else /* !CONFIG_BUG */
 167 #ifndef HAVE_ARCH_BUG
 168 #define BUG() do {} while (1)
 169 #endif
 170
 171 #ifndef HAVE_ARCH_BUG_ON
 172 #define BUG_ON(condition) do { if (condition) BUG(); } while (0)
 173 #endif
 174
 175 #ifndef HAVE_ARCH_WARN_ON
 176 #define WARN_ON(condition) ({                                           \
 177         int __ret_warn_on = !!(condition);                              \
 178         unlikely(__ret_warn_on);                                        \
 179 })
 180 #endif
 181
 182 #ifndef WARN
 183 #define WARN(condition, format...) ({                                   \
 184         int __ret_warn_on = !!(condition);                              \
 185         no_printk(format);                                              \
 186         unlikely(__ret_warn_on);                                        \
 187 })
 188 #endif
 189
 190 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 191 #define WARN_ONCE(condition, format...) WARN(condition, format)
 192 #define WARN_TAINT(condition, taint, format...) WARN(condition, format)
 193 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
 194
 195 #endif
 196
 197 /*
 198  * WARN_ON_SMP() is for cases that the warning is either
 199  * meaningless for !SMP or may even cause failures.
 200  * This is usually used for cases that we have
 201  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
 202  * returns 0 for uniprocessor settings.
 203  * It can also be used with values that are only defined
 204  * on SMP:
 205  *
 206  * struct foo {
 207  *  [...]
 208  * #ifdef CONFIG_SMP
 209  *      int bar;
 210  * #endif
 211  * };
 212  *
 213  * void func(struct foo *zoot)
 214  * {
 215  *      WARN_ON_SMP(!zoot->bar);
 216  *
 217  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
 218  * and should be a nop and return false for uniprocessor.
 219  *
 220  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
 221  * and x is true.
 222  */
 223 #ifdef CONFIG_SMP
 224 # define WARN_ON_SMP(x)                 WARN_ON(x)
 225 #else
 226 /*
 227  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
 228  * a stand alone line statement or as a condition in an if ()
 229  * statement.
 230  * A simple "0" would cause gcc to give a "statement has no effect"
 231  * warning.
 232  */
 233 # define WARN_ON_SMP(x)                 ({0;})
 234 #endif
 235
 236 #endif /* __ASSEMBLY__ */
 237
 238 #endif