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 /*
  65  * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
  66  * significant kernel issues that need prompt attention if they should ever
  67  * appear at runtime.
  68  *
  69  * Do not use these macros when checking for invalid external inputs
  70  * (e.g. invalid system call arguments, or invalid data coming from
  71  * network/devices), and on transient conditions like ENOMEM or EAGAIN.
  72  * These macros should be used for recoverable kernel issues only.
  73  * For invalid external inputs, transient conditions, etc use
  74  * pr_err[_once/_ratelimited]() followed by dump_stack(), if necessary.
  75  * Do not include "BUG"/"WARNING" in format strings manually to make these
  76  * conditions distinguishable from kernel issues.
  77  *
  78  * Use the versions with printk format strings to provide better diagnostics.
  79  */
  80 #ifndef __WARN_FLAGS
  81 extern __printf(4, 5)
  82 void warn_slowpath_fmt(const char *file, const int line, unsigned taint,
  83                        const char *fmt, ...);
  84 #define __WARN()                __WARN_printf(TAINT_WARN, NULL)
  85 #define __WARN_printf(taint, arg...)                                    \
  86         warn_slowpath_fmt(__FILE__, __LINE__, taint, arg)
  87 #else
  88 extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
  89 #define __WARN() do {                                                   \
  90                 printk(KERN_WARNING CUT_HERE);                          \
  91                 __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN));                \
  92         } while (0)
  93 #define __WARN_printf(taint, arg...) do {                               \
  94                 __warn_printk(arg);                                     \
  95                 __WARN_FLAGS(BUGFLAG_TAINT(taint));                     \
  96         } while (0)
  97 #define WARN_ON_ONCE(condition) ({                              \
  98         int __ret_warn_on = !!(condition);                      \
  99         if (unlikely(__ret_warn_on))                            \
 100                 __WARN_FLAGS(BUGFLAG_ONCE |                     \
 101                              BUGFLAG_TAINT(TAINT_WARN));        \
 102         unlikely(__ret_warn_on);                                \
 103 })
 104 #endif
 105
 106 /* used internally by panic.c */
 107 struct warn_args;
 108 struct pt_regs;
 109
 110 void __warn(const char *file, int line, void *caller, unsigned taint,
 111             struct pt_regs *regs, struct warn_args *args);
 112
 113 #ifndef WARN_ON
 114 #define WARN_ON(condition) ({                                           \
 115         int __ret_warn_on = !!(condition);                              \
 116         if (unlikely(__ret_warn_on))                                    \
 117                 __WARN();                                               \
 118         unlikely(__ret_warn_on);                                        \
 119 })
 120 #endif
 121
 122 #ifndef WARN
 123 #define WARN(condition, format...) ({                                   \
 124         int __ret_warn_on = !!(condition);                              \
 125         if (unlikely(__ret_warn_on))                                    \
 126                 __WARN_printf(TAINT_WARN, format);                      \
 127         unlikely(__ret_warn_on);                                        \
 128 })
 129 #endif
 130
 131 #define WARN_TAINT(condition, taint, format...) ({                      \
 132         int __ret_warn_on = !!(condition);                              \
 133         if (unlikely(__ret_warn_on))                                    \
 134                 __WARN_printf(taint, format);                           \
 135         unlikely(__ret_warn_on);                                        \
 136 })
 137
 138 #ifndef WARN_ON_ONCE
 139 #define WARN_ON_ONCE(condition) ({                              \
 140         static bool __section(.data.once) __warned;             \
 141         int __ret_warn_once = !!(condition);                    \
 142                                                                 \
 143         if (unlikely(__ret_warn_once && !__warned)) {           \
 144                 __warned = true;                                \
 145                 WARN_ON(1);                                     \
 146         }                                                       \
 147         unlikely(__ret_warn_once);                              \
 148 })
 149 #endif
 150
 151 #define WARN_ONCE(condition, format...) ({                      \
 152         static bool __section(.data.once) __warned;             \
 153         int __ret_warn_once = !!(condition);                    \
 154                                                                 \
 155         if (unlikely(__ret_warn_once && !__warned)) {           \
 156                 __warned = true;                                \
 157                 WARN(1, format);                                \
 158         }                                                       \
 159         unlikely(__ret_warn_once);                              \
 160 })
 161
 162 #define WARN_TAINT_ONCE(condition, taint, format...)    ({      \
 163         static bool __section(.data.once) __warned;             \
 164         int __ret_warn_once = !!(condition);                    \
 165                                                                 \
 166         if (unlikely(__ret_warn_once && !__warned)) {           \
 167                 __warned = true;                                \
 168                 WARN_TAINT(1, taint, format);                   \
 169         }                                                       \
 170         unlikely(__ret_warn_once);                              \
 171 })
 172
 173 #else /* !CONFIG_BUG */
 174 #ifndef HAVE_ARCH_BUG
 175 #define BUG() do {} while (1)
 176 #endif
 177
 178 #ifndef HAVE_ARCH_BUG_ON
 179 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
 180 #endif
 181
 182 #ifndef HAVE_ARCH_WARN_ON
 183 #define WARN_ON(condition) ({                                           \
 184         int __ret_warn_on = !!(condition);                              \
 185         unlikely(__ret_warn_on);                                        \
 186 })
 187 #endif
 188
 189 #ifndef WARN
 190 #define WARN(condition, format...) ({                                   \
 191         int __ret_warn_on = !!(condition);                              \
 192         no_printk(format);                                              \
 193         unlikely(__ret_warn_on);                                        \
 194 })
 195 #endif
 196
 197 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 198 #define WARN_ONCE(condition, format...) WARN(condition, format)
 199 #define WARN_TAINT(condition, taint, format...) WARN(condition, format)
 200 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
 201
 202 #endif
 203
 204 /*
 205  * WARN_ON_SMP() is for cases that the warning is either
 206  * meaningless for !SMP or may even cause failures.
 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