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
24struct warn_args;
25struct pt_regs;
26
27void __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
33struct 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 */
90extern __printf(4, 5)
91void warn_slowpath_fmt(const char *file, const int line, unsigned taint,
92 const char *fmt, ...);
93extern __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
230