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