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