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