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 #define CUT_HERE                "------------[ cut here ]------------\n"
   8
   9 #ifdef CONFIG_GENERIC_BUG
  10 #define BUGFLAG_WARNING         (1 << 0)
  11 #define BUGFLAG_ONCE            (1 << 1)
  12 #define BUGFLAG_DONE            (1 << 2)
  13 #define BUGFLAG_TAINT(taint)    ((taint) << 8)
  14 #define BUG_GET_TAINT(bug)      ((bug)->flags >> 8)
  15 #endif
  16
  17 #ifndef __ASSEMBLY__
  18 #include <linux/kernel.h>
  19
  20 #ifdef CONFIG_BUG
  21
  22 #ifdef CONFIG_GENERIC_BUG
  23 struct bug_entry {
  24 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  25         unsigned long   bug_addr;
  26 #else
  27         signed int      bug_addr_disp;
  28 #endif
  29 #ifdef CONFIG_DEBUG_BUGVERBOSE
  30 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  31         const char      *file;
  32 #else
  33         signed int      file_disp;
  34 #endif
  35         unsigned short  line;
  36 #endif
  37         unsigned short  flags;
  38 };
  39 #endif  /* CONFIG_GENERIC_BUG */
  40
  41 /*
  42  * Don't use BUG() or BUG_ON() unless there's really no way out; one
  43  * example might be detecting data structure corruption in the middle
  44  * of an operation that can't be backed out of.  If the (sub)system
  45  * can somehow continue operating, perhaps with reduced functionality,
  46  * it's probably not BUG-worthy.
  47  *
  48  * If you're tempted to BUG(), think again:  is completely giving up
  49  * really the *only* solution?  There are usually better options, where
  50  * users don't need to reboot ASAP and can mostly shut down cleanly.
  51  */
  52 #ifndef HAVE_ARCH_BUG
  53 #define BUG() do { \
  54         printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
  55         panic("BUG!"); \
  56 } while (0)
  57 #endif
  58
  59 #ifndef HAVE_ARCH_BUG_ON
  60 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
  61 #endif
  62
  63 #ifdef __WARN_FLAGS
  64 #define __WARN_TAINT(taint)             __WARN_FLAGS(BUGFLAG_TAINT(taint))
  65 #define __WARN_ONCE_TAINT(taint)        __WARN_FLAGS(BUGFLAG_ONCE|BUGFLAG_TAINT(taint))
  66
  67 #define WARN_ON_ONCE(condition) ({                              \
  68         int __ret_warn_on = !!(condition);                      \
  69         if (unlikely(__ret_warn_on))                            \
  70                 __WARN_ONCE_TAINT(TAINT_WARN);                  \
  71         unlikely(__ret_warn_on);                                \
  72 })
  73 #endif
  74
  75 /*
  76  * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
  77  * significant issues that need prompt attention if they should ever
  78  * appear at runtime.  Use the versions with printk format strings
  79  * to provide better diagnostics.
  80  */
  81 #ifndef __WARN_TAINT
  82 extern __printf(3, 4)
  83 void warn_slowpath_fmt(const char *file, const int line,
  84                        const char *fmt, ...);
  85 extern __printf(4, 5)
  86 void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
  87                              const char *fmt, ...);
  88 extern void warn_slowpath_null(const char *file, const int line);
  89 #define WANT_WARN_ON_SLOWPATH
  90 #define __WARN()                warn_slowpath_null(__FILE__, __LINE__)
  91 #define __WARN_printf(arg...)   warn_slowpath_fmt(__FILE__, __LINE__, arg)
  92 #define __WARN_printf_taint(taint, arg...)                              \
  93         warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
  94 #else
  95 extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
  96 #define __WARN()                __WARN_TAINT(TAINT_WARN)
  97 #define __WARN_printf(arg...)   do { __warn_printk(arg); __WARN(); } while (0)
  98 #define __WARN_printf_taint(taint, arg...)                              \
  99         do { __warn_printk(arg); __WARN_TAINT(taint); } while (0)
 100 #endif
 101
 102 /* used internally by panic.c */
 103 struct warn_args;
 104 struct pt_regs;
 105
 106 void __warn(const char *file, int line, void *caller, unsigned taint,
 107             struct pt_regs *regs, struct warn_args *args);
 108
 109 #ifndef WARN_ON
 110 #define WARN_ON(condition) ({                                           \
 111         int __ret_warn_on = !!(condition);                              \
 112         if (unlikely(__ret_warn_on))                                    \
 113                 __WARN();                                               \
 114         unlikely(__ret_warn_on);                                        \
 115 })
 116 #endif
 117
 118 #ifndef WARN
 119 #define WARN(condition, format...) ({                                   \
 120         int __ret_warn_on = !!(condition);                              \
 121         if (unlikely(__ret_warn_on))                                    \
 122                 __WARN_printf(format);                                  \
 123         unlikely(__ret_warn_on);                                        \
 124 })
 125 #endif
 126
 127 #define WARN_TAINT(condition, taint, format...) ({                      \
 128         int __ret_warn_on = !!(condition);                              \
 129         if (unlikely(__ret_warn_on))                                    \
 130                 __WARN_printf_taint(taint, format);                     \
 131         unlikely(__ret_warn_on);                                        \
 132 })
 133
 134 #ifndef WARN_ON_ONCE
 135 #define WARN_ON_ONCE(condition) ({                              \
 136         static bool __section(.data.once) __warned;             \
 137         int __ret_warn_once = !!(condition);                    \
 138                                                                 \
 139         if (unlikely(__ret_warn_once && !__warned)) {           \
 140                 __warned = true;                                \
 141                 WARN_ON(1);                                     \
 142         }                                                       \
 143         unlikely(__ret_warn_once);                              \
 144 })
 145 #endif
 146
 147 #define WARN_ONCE(condition, format...) ({                      \
 148         static bool __section(.data.once) __warned;             \
 149         int __ret_warn_once = !!(condition);                    \
 150                                                                 \
 151         if (unlikely(__ret_warn_once && !__warned)) {           \
 152                 __warned = true;                                \
 153                 WARN(1, format);                                \
 154         }                                                       \
 155         unlikely(__ret_warn_once);                              \
 156 })
 157
 158 #define WARN_TAINT_ONCE(condition, taint, format...)    ({      \
 159         static bool __section(.data.once) __warned;             \
 160         int __ret_warn_once = !!(condition);                    \
 161                                                                 \
 162         if (unlikely(__ret_warn_once && !__warned)) {           \
 163                 __warned = true;                                \
 164                 WARN_TAINT(1, taint, format);                   \
 165         }                                                       \
 166         unlikely(__ret_warn_once);                              \
 167 })
 168
 169 #else /* !CONFIG_BUG */
 170 #ifndef HAVE_ARCH_BUG
 171 #define BUG() do {} while (1)
 172 #endif
 173
 174 #ifndef HAVE_ARCH_BUG_ON
 175 #define BUG_ON(condition) do { if (condition) BUG(); } while (0)
 176 #endif
 177
 178 #ifndef HAVE_ARCH_WARN_ON
 179 #define WARN_ON(condition) ({                                           \
 180         int __ret_warn_on = !!(condition);                              \
 181         unlikely(__ret_warn_on);                                        \
 182 })
 183 #endif
 184
 185 #ifndef WARN
 186 #define WARN(condition, format...) ({                                   \
 187         int __ret_warn_on = !!(condition);                              \
 188         no_printk(format);                                              \
 189         unlikely(__ret_warn_on);                                        \
 190 })
 191 #endif
 192
 193 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 194 #define WARN_ONCE(condition, format...) WARN(condition, format)
 195 #define WARN_TAINT(condition, taint, format...) WARN(condition, format)
 196 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
 197
 198 #endif
 199
 200 /*
 201  * WARN_ON_SMP() is for cases that the warning is either
 202  * meaningless for !SMP or may even cause failures.
 203  * This is usually used for cases that we have
 204  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
 205  * returns 0 for uniprocessor settings.
 206  * It can also be used with values that are only defined
 207  * on SMP:
 208  *
 209  * struct foo {
 210  *  [...]
 211  * #ifdef CONFIG_SMP
 212  *      int bar;
 213  * #endif
 214  * };
 215  *
 216  * void func(struct foo *zoot)
 217  * {
 218  *      WARN_ON_SMP(!zoot->bar);
 219  *
 220  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
 221  * and should be a nop and return false for uniprocessor.
 222  *
 223  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
 224  * and x is true.
 225  */
 226 #ifdef CONFIG_SMP
 227 # define WARN_ON_SMP(x)                 WARN_ON(x)
 228 #else
 229 /*
 230  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
 231  * a stand alone line statement or as a condition in an if ()
 232  * statement.
 233  * A simple "0" would cause gcc to give a "statement has no effect"
 234  * warning.
 235  */
 236 # define WARN_ON_SMP(x)                 ({0;})
 237 #endif
 238
 239 #endif /* __ASSEMBLY__ */
 240
 241 #endif