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 kernel issues that need prompt attention if they should ever
  79  * appear at runtime.
  80  *
  81  * Do not use these macros when checking for invalid external inputs
  82  * (e.g. invalid system call arguments, or invalid data coming from
  83  * network/devices), and on transient conditions like ENOMEM or EAGAIN.
  84  * These macros should be used for recoverable kernel issues only.
  85  * For invalid external inputs, transient conditions, etc use
  86  * pr_err[_once/_ratelimited]() followed by dump_stack(), if necessary.
  87  * Do not include "BUG"/"WARNING" in format strings manually to make these
  88  * conditions distinguishable from kernel issues.
  89  *
  90  * Use the versions with printk format strings to provide better diagnostics.
  91  */
  92 #ifndef __WARN_TAINT
  93 extern __printf(3, 4)
  94 void warn_slowpath_fmt(const char *file, const int line,
  95                        const char *fmt, ...);
  96 extern __printf(4, 5)
  97 void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
  98                              const char *fmt, ...);
  99 extern void warn_slowpath_null(const char *file, const int line);
 100 #define WANT_WARN_ON_SLOWPATH
 101 #define __WARN()                warn_slowpath_null(__FILE__, __LINE__)
 102 #define __WARN_printf(arg...)   warn_slowpath_fmt(__FILE__, __LINE__, arg)
 103 #define __WARN_printf_taint(taint, arg...)                              \
 104         warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
 105 #else
 106 extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
 107 #define __WARN()                __WARN_TAINT(TAINT_WARN)
 108 #define __WARN_printf(arg...)   do { __warn_printk(arg); __WARN(); } while (0)
 109 #define __WARN_printf_taint(taint, arg...)                              \
 110         do { __warn_printk(arg); __WARN_TAINT(taint); } while (0)
 111 #endif
 112
 113 /* used internally by panic.c */
 114 struct warn_args;
 115 struct pt_regs;
 116
 117 void __warn(const char *file, int line, void *caller, unsigned taint,
 118             struct pt_regs *regs, struct warn_args *args);
 119
 120 #ifndef WARN_ON
 121 #define WARN_ON(condition) ({                                           \
 122         int __ret_warn_on = !!(condition);                              \
 123         if (unlikely(__ret_warn_on))                                    \
 124                 __WARN();                                               \
 125         unlikely(__ret_warn_on);                                        \
 126 })
 127 #endif
 128
 129 #ifndef WARN
 130 #define WARN(condition, format...) ({                                   \
 131         int __ret_warn_on = !!(condition);                              \
 132         if (unlikely(__ret_warn_on))                                    \
 133                 __WARN_printf(format);                                  \
 134         unlikely(__ret_warn_on);                                        \
 135 })
 136 #endif
 137
 138 #define WARN_TAINT(condition, taint, format...) ({                      \
 139         int __ret_warn_on = !!(condition);                              \
 140         if (unlikely(__ret_warn_on))                                    \
 141                 __WARN_printf_taint(taint, format);                     \
 142         unlikely(__ret_warn_on);                                        \
 143 })
 144
 145 #ifndef WARN_ON_ONCE
 146 #define WARN_ON_ONCE(condition) ({                              \
 147         static bool __section(.data.once) __warned;             \
 148         int __ret_warn_once = !!(condition);                    \
 149                                                                 \
 150         if (unlikely(__ret_warn_once && !__warned)) {           \
 151                 __warned = true;                                \
 152                 WARN_ON(1);                                     \
 153         }                                                       \
 154         unlikely(__ret_warn_once);                              \
 155 })
 156 #endif
 157
 158 #define WARN_ONCE(condition, 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(1, format);                                \
 165         }                                                       \
 166         unlikely(__ret_warn_once);                              \
 167 })
 168
 169 #define WARN_TAINT_ONCE(condition, taint, format...)    ({      \
 170         static bool __section(.data.once) __warned;             \
 171         int __ret_warn_once = !!(condition);                    \
 172                                                                 \
 173         if (unlikely(__ret_warn_once && !__warned)) {           \
 174                 __warned = true;                                \
 175                 WARN_TAINT(1, taint, format);                   \
 176         }                                                       \
 177         unlikely(__ret_warn_once);                              \
 178 })
 179
 180 #else /* !CONFIG_BUG */
 181 #ifndef HAVE_ARCH_BUG
 182 #define BUG() do {} while (1)
 183 #endif
 184
 185 #ifndef HAVE_ARCH_BUG_ON
 186 #define BUG_ON(condition) do { if (condition) BUG(); } while (0)
 187 #endif
 188
 189 #ifndef HAVE_ARCH_WARN_ON
 190 #define WARN_ON(condition) ({                                           \
 191         int __ret_warn_on = !!(condition);                              \
 192         unlikely(__ret_warn_on);                                        \
 193 })
 194 #endif
 195
 196 #ifndef WARN
 197 #define WARN(condition, format...) ({                                   \
 198         int __ret_warn_on = !!(condition);                              \
 199         no_printk(format);                                              \
 200         unlikely(__ret_warn_on);                                        \
 201 })
 202 #endif
 203
 204 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 205 #define WARN_ONCE(condition, format...) WARN(condition, format)
 206 #define WARN_TAINT(condition, taint, format...) WARN(condition, format)
 207 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
 208
 209 #endif
 210
 211 /*
 212  * WARN_ON_SMP() is for cases that the warning is either
 213  * meaningless for !SMP or may even cause failures.
 214  * It can also be used with values that are only defined
 215  * on SMP:
 216  *
 217  * struct foo {
 218  *  [...]
 219  * #ifdef CONFIG_SMP
 220  *      int bar;
 221  * #endif
 222  * };
 223  *
 224  * void func(struct foo *zoot)
 225  * {
 226  *      WARN_ON_SMP(!zoot->bar);
 227  *
 228  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
 229  * and should be a nop and return false for uniprocessor.
 230  *
 231  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
 232  * and x is true.
 233  */
 234 #ifdef CONFIG_SMP
 235 # define WARN_ON_SMP(x)                 WARN_ON(x)
 236 #else
 237 /*
 238  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
 239  * a stand alone line statement or as a condition in an if ()
 240  * statement.
 241  * A simple "0" would cause gcc to give a "statement has no effect"
 242  * warning.
 243  */
 244 # define WARN_ON_SMP(x)                 ({0;})
 245 #endif
 246
 247 #endif /* __ASSEMBLY__ */
 248
 249 #endif