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         barrier_before_unreachable(); \
  56         panic("BUG!"); \
  57 } while (0)
  58 #endif
  59
  60 #ifndef HAVE_ARCH_BUG_ON
  61 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
  62 #endif
  63
  64 #ifdef __WARN_FLAGS
  65 #define __WARN_TAINT(taint)             __WARN_FLAGS(BUGFLAG_TAINT(taint))
  66 #define __WARN_ONCE_TAINT(taint)        __WARN_FLAGS(BUGFLAG_ONCE|BUGFLAG_TAINT(taint))
  67
  68 #define WARN_ON_ONCE(condition) ({                              \
  69         int __ret_warn_on = !!(condition);                      \
  70         if (unlikely(__ret_warn_on))                            \
  71                 __WARN_ONCE_TAINT(TAINT_WARN);                  \
  72         unlikely(__ret_warn_on);                                \
  73 })
  74 #endif
  75
  76 /*
  77  * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
  78  * significant issues that need prompt attention if they should ever
  79  * appear at runtime.  Use the versions with printk format strings
  80  * to provide better diagnostics.
  81  */
  82 #ifndef __WARN_TAINT
  83 extern __printf(3, 4)
  84 void warn_slowpath_fmt(const char *file, const int line,
  85                        const char *fmt, ...);
  86 extern __printf(4, 5)
  87 void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
  88                              const char *fmt, ...);
  89 extern void warn_slowpath_null(const char *file, const int line);
  90 #define WANT_WARN_ON_SLOWPATH
  91 #define __WARN()                warn_slowpath_null(__FILE__, __LINE__)
  92 #define __WARN_printf(arg...)   warn_slowpath_fmt(__FILE__, __LINE__, arg)
  93 #define __WARN_printf_taint(taint, arg...)                              \
  94         warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
  95 #else
  96 extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
  97 #define __WARN()                __WARN_TAINT(TAINT_WARN)
  98 #define __WARN_printf(arg...)   do { __warn_printk(arg); __WARN(); } while (0)
  99 #define __WARN_printf_taint(taint, arg...)                              \
 100         do { __warn_printk(arg); __WARN_TAINT(taint); } while (0)
 101 #endif
 102
 103 /* used internally by panic.c */
 104 struct warn_args;
 105 struct pt_regs;
 106
 107 void __warn(const char *file, int line, void *caller, unsigned taint,
 108             struct pt_regs *regs, struct warn_args *args);
 109
 110 #ifndef WARN_ON
 111 #define WARN_ON(condition) ({                                           \
 112         int __ret_warn_on = !!(condition);                              \
 113         if (unlikely(__ret_warn_on))                                    \
 114                 __WARN();                                               \
 115         unlikely(__ret_warn_on);                                        \
 116 })
 117 #endif
 118
 119 #ifndef WARN
 120 #define WARN(condition, format...) ({                                   \
 121         int __ret_warn_on = !!(condition);                              \
 122         if (unlikely(__ret_warn_on))                                    \
 123                 __WARN_printf(format);                                  \
 124         unlikely(__ret_warn_on);                                        \
 125 })
 126 #endif
 127
 128 #define WARN_TAINT(condition, taint, format...) ({                      \
 129         int __ret_warn_on = !!(condition);                              \
 130         if (unlikely(__ret_warn_on))                                    \
 131                 __WARN_printf_taint(taint, format);                     \
 132         unlikely(__ret_warn_on);                                        \
 133 })
 134
 135 #ifndef WARN_ON_ONCE
 136 #define WARN_ON_ONCE(condition) ({                              \
 137         static bool __section(.data.once) __warned;             \
 138         int __ret_warn_once = !!(condition);                    \
 139                                                                 \
 140         if (unlikely(__ret_warn_once && !__warned)) {           \
 141                 __warned = true;                                \
 142                 WARN_ON(1);                                     \
 143         }                                                       \
 144         unlikely(__ret_warn_once);                              \
 145 })
 146 #endif
 147
 148 #define WARN_ONCE(condition, format...) ({                      \
 149         static bool __section(.data.once) __warned;             \
 150         int __ret_warn_once = !!(condition);                    \
 151                                                                 \
 152         if (unlikely(__ret_warn_once && !__warned)) {           \
 153                 __warned = true;                                \
 154                 WARN(1, format);                                \
 155         }                                                       \
 156         unlikely(__ret_warn_once);                              \
 157 })
 158
 159 #define WARN_TAINT_ONCE(condition, taint, format...)    ({      \
 160         static bool __section(.data.once) __warned;             \
 161         int __ret_warn_once = !!(condition);                    \
 162                                                                 \
 163         if (unlikely(__ret_warn_once && !__warned)) {           \
 164                 __warned = true;                                \
 165                 WARN_TAINT(1, taint, format);                   \
 166         }                                                       \
 167         unlikely(__ret_warn_once);                              \
 168 })
 169
 170 #else /* !CONFIG_BUG */
 171 #ifndef HAVE_ARCH_BUG
 172 #define BUG() do {} while (1)
 173 #endif
 174
 175 #ifndef HAVE_ARCH_BUG_ON
 176 #define BUG_ON(condition) do { if (condition) BUG(); } while (0)
 177 #endif
 178
 179 #ifndef HAVE_ARCH_WARN_ON
 180 #define WARN_ON(condition) ({                                           \
 181         int __ret_warn_on = !!(condition);                              \
 182         unlikely(__ret_warn_on);                                        \
 183 })
 184 #endif
 185
 186 #ifndef WARN
 187 #define WARN(condition, format...) ({                                   \
 188         int __ret_warn_on = !!(condition);                              \
 189         no_printk(format);                                              \
 190         unlikely(__ret_warn_on);                                        \
 191 })
 192 #endif
 193
 194 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 195 #define WARN_ONCE(condition, format...) WARN(condition, format)
 196 #define WARN_TAINT(condition, taint, format...) WARN(condition, format)
 197 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
 198
 199 #endif
 200
 201 /*
 202  * WARN_ON_SMP() is for cases that the warning is either
 203  * meaningless for !SMP or may even cause failures.
 204  * This is usually used for cases that we have
 205  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
 206  * returns 0 for uniprocessor settings.
 207  * It can also be used with values that are only defined
 208  * on SMP:
 209  *
 210  * struct foo {
 211  *  [...]
 212  * #ifdef CONFIG_SMP
 213  *      int bar;
 214  * #endif
 215  * };
 216  *
 217  * void func(struct foo *zoot)
 218  * {
 219  *      WARN_ON_SMP(!zoot->bar);
 220  *
 221  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
 222  * and should be a nop and return false for uniprocessor.
 223  *
 224  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
 225  * and x is true.
 226  */
 227 #ifdef CONFIG_SMP
 228 # define WARN_ON_SMP(x)                 WARN_ON(x)
 229 #else
 230 /*
 231  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
 232  * a stand alone line statement or as a condition in an if ()
 233  * statement.
 234  * A simple "0" would cause gcc to give a "statement has no effect"
 235  * warning.
 236  */
 237 # define WARN_ON_SMP(x)                 ({0;})
 238 #endif
 239
 240 #endif /* __ASSEMBLY__ */
 241
 242 #endif