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 #include <linux/instrumentation.h>
   7
   8 #define CUT_HERE                "------------[ cut here ]------------\n"
   9
  10 #ifdef CONFIG_GENERIC_BUG
  11 #define BUGFLAG_WARNING         (1 << 0)
  12 #define BUGFLAG_ONCE            (1 << 1)
  13 #define BUGFLAG_DONE            (1 << 2)
  14 #define BUGFLAG_NO_CUT_HERE     (1 << 3)        /* CUT_HERE already sent */
  15 #define BUGFLAG_TAINT(taint)    ((taint) << 8)
  16 #define BUG_GET_TAINT(bug)      ((bug)->flags >> 8)
  17 #endif
  18
  19 #ifndef __ASSEMBLY__
  20 #include <linux/kernel.h>
  21
  22 #ifdef CONFIG_BUG
  23
  24 #ifdef CONFIG_GENERIC_BUG
  25 struct bug_entry {
  26 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  27         unsigned long   bug_addr;
  28 #else
  29         signed int      bug_addr_disp;
  30 #endif
  31 #ifdef CONFIG_DEBUG_BUGVERBOSE
  32 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  33         const char      *file;
  34 #else
  35         signed int      file_disp;
  36 #endif
  37         unsigned short  line;
  38 #endif
  39         unsigned short  flags;
  40 };
  41 #endif  /* CONFIG_GENERIC_BUG */
  42
  43 /*
  44  * Don't use BUG() or BUG_ON() unless there's really no way out; one
  45  * example might be detecting data structure corruption in the middle
  46  * of an operation that can't be backed out of.  If the (sub)system
  47  * can somehow continue operating, perhaps with reduced functionality,
  48  * it's probably not BUG-worthy.
  49  *
  50  * If you're tempted to BUG(), think again:  is completely giving up
  51  * really the *only* solution?  There are usually better options, where
  52  * users don't need to reboot ASAP and can mostly shut down cleanly.
  53  */
  54 #ifndef HAVE_ARCH_BUG
  55 #define BUG() do { \
  56         printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
  57         barrier_before_unreachable(); \
  58         panic("BUG!"); \
  59 } while (0)
  60 #endif
  61
  62 #ifndef HAVE_ARCH_BUG_ON
  63 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
  64 #endif
  65
  66 /*
  67  * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
  68  * significant kernel issues that need prompt attention if they should ever
  69  * appear at runtime.
  70  *
  71  * Do not use these macros when checking for invalid external inputs
  72  * (e.g. invalid system call arguments, or invalid data coming from
  73  * network/devices), and on transient conditions like ENOMEM or EAGAIN.
  74  * These macros should be used for recoverable kernel issues only.
  75  * For invalid external inputs, transient conditions, etc use
  76  * pr_err[_once/_ratelimited]() followed by dump_stack(), if necessary.
  77  * Do not include "BUG"/"WARNING" in format strings manually to make these
  78  * conditions distinguishable from kernel issues.
  79  *
  80  * Use the versions with printk format strings to provide better diagnostics.
  81  */
  82 #ifndef __WARN_FLAGS
  83 extern __printf(4, 5)
  84 void warn_slowpath_fmt(const char *file, const int line, unsigned taint,
  85                        const char *fmt, ...);
  86 #define __WARN()                __WARN_printf(TAINT_WARN, NULL)
  87 #define __WARN_printf(taint, arg...) do {                               \
  88                 instrumentation_begin();                                \
  89                 warn_slowpath_fmt(__FILE__, __LINE__, taint, arg);      \
  90                 instrumentation_end();                                  \
  91         } while (0)
  92 #else
  93 extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
  94 #define __WARN()                __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
  95 #define __WARN_printf(taint, arg...) do {                               \
  96                 instrumentation_begin();                                \
  97                 __warn_printk(arg);                                     \
  98                 __WARN_FLAGS(BUGFLAG_NO_CUT_HERE | BUGFLAG_TAINT(taint));\
  99                 instrumentation_end();                                  \
 100         } while (0)
 101 #define WARN_ON_ONCE(condition) ({                              \
 102         int __ret_warn_on = !!(condition);                      \
 103         if (unlikely(__ret_warn_on))                            \
 104                 __WARN_FLAGS(BUGFLAG_ONCE |                     \
 105                              BUGFLAG_TAINT(TAINT_WARN));        \
 106         unlikely(__ret_warn_on);                                \
 107 })
 108 #endif
 109
 110 /* used internally by panic.c */
 111 struct warn_args;
 112 struct pt_regs;
 113
 114 void __warn(const char *file, int line, void *caller, unsigned taint,
 115             struct pt_regs *regs, struct warn_args *args);
 116
 117 #ifndef WARN_ON
 118 #define WARN_ON(condition) ({                                           \
 119         int __ret_warn_on = !!(condition);                              \
 120         if (unlikely(__ret_warn_on))                                    \
 121                 __WARN();                                               \
 122         unlikely(__ret_warn_on);                                        \
 123 })
 124 #endif
 125
 126 #ifndef WARN
 127 #define WARN(condition, format...) ({                                   \
 128         int __ret_warn_on = !!(condition);                              \
 129         if (unlikely(__ret_warn_on))                                    \
 130                 __WARN_printf(TAINT_WARN, format);                      \
 131         unlikely(__ret_warn_on);                                        \
 132 })
 133 #endif
 134
 135 #define WARN_TAINT(condition, taint, format...) ({                      \
 136         int __ret_warn_on = !!(condition);                              \
 137         if (unlikely(__ret_warn_on))                                    \
 138                 __WARN_printf(taint, format);                           \
 139         unlikely(__ret_warn_on);                                        \
 140 })
 141
 142 #ifndef WARN_ON_ONCE
 143 #define WARN_ON_ONCE(condition) ({                              \
 144         static bool __section(".data.once") __warned;           \
 145         int __ret_warn_once = !!(condition);                    \
 146                                                                 \
 147         if (unlikely(__ret_warn_once && !__warned)) {           \
 148                 __warned = true;                                \
 149                 WARN_ON(1);                                     \
 150         }                                                       \
 151         unlikely(__ret_warn_once);                              \
 152 })
 153 #endif
 154
 155 #define WARN_ONCE(condition, format...) ({                      \
 156         static bool __section(".data.once") __warned;           \
 157         int __ret_warn_once = !!(condition);                    \
 158                                                                 \
 159         if (unlikely(__ret_warn_once && !__warned)) {           \
 160                 __warned = true;                                \
 161                 WARN(1, format);                                \
 162         }                                                       \
 163         unlikely(__ret_warn_once);                              \
 164 })
 165
 166 #define WARN_TAINT_ONCE(condition, taint, format...)    ({      \
 167         static bool __section(".data.once") __warned;           \
 168         int __ret_warn_once = !!(condition);                    \
 169                                                                 \
 170         if (unlikely(__ret_warn_once && !__warned)) {           \
 171                 __warned = true;                                \
 172                 WARN_TAINT(1, taint, format);                   \
 173         }                                                       \
 174         unlikely(__ret_warn_once);                              \
 175 })
 176
 177 #else /* !CONFIG_BUG */
 178 #ifndef HAVE_ARCH_BUG
 179 #define BUG() do {} while (1)
 180 #endif
 181
 182 #ifndef HAVE_ARCH_BUG_ON
 183 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
 184 #endif
 185
 186 #ifndef HAVE_ARCH_WARN_ON
 187 #define WARN_ON(condition) ({                                           \
 188         int __ret_warn_on = !!(condition);                              \
 189         unlikely(__ret_warn_on);                                        \
 190 })
 191 #endif
 192
 193 #ifndef WARN
 194 #define WARN(condition, format...) ({                                   \
 195         int __ret_warn_on = !!(condition);                              \
 196         no_printk(format);                                              \
 197         unlikely(__ret_warn_on);                                        \
 198 })
 199 #endif
 200
 201 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 202 #define WARN_ONCE(condition, format...) WARN(condition, format)
 203 #define WARN_TAINT(condition, taint, format...) WARN(condition, format)
 204 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
 205
 206 #endif
 207
 208 /*
 209  * WARN_ON_SMP() is for cases that the warning is either
 210  * meaningless for !SMP or may even cause failures.
 211  * It can also be used with values that are only defined
 212  * on SMP:
 213  *
 214  * struct foo {
 215  *  [...]
 216  * #ifdef CONFIG_SMP
 217  *      int bar;
 218  * #endif
 219  * };
 220  *
 221  * void func(struct foo *zoot)
 222  * {
 223  *      WARN_ON_SMP(!zoot->bar);
 224  *
 225  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
 226  * and should be a nop and return false for uniprocessor.
 227  *
 228  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
 229  * and x is true.
 230  */
 231 #ifdef CONFIG_SMP
 232 # define WARN_ON_SMP(x)                 WARN_ON(x)
 233 #else
 234 /*
 235  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
 236  * a stand alone line statement or as a condition in an if ()
 237  * statement.
 238  * A simple "0" would cause gcc to give a "statement has no effect"
 239  * warning.
 240  */
 241 # define WARN_ON_SMP(x)                 ({0;})
 242 #endif
 243
 244 #endif /* __ASSEMBLY__ */
 245
 246 #endif