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