LXR linux/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
  27struct 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
  85extern __printf(4, 5)
  86void 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
  95extern __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 */
 113struct warn_args;
 114struct pt_regs;
 115
 116void __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
 241