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_ARGS		(1 << 4)
 17#define BUGFLAG_TAINT(taint)	((taint) << 8)
 18#define BUG_GET_TAINT(bug)	((bug)->flags >> 8)
 19#endif
 20
 21#ifndef WARN_CONDITION_STR
 22#ifdef CONFIG_DEBUG_BUGVERBOSE_DETAILED
 23# define WARN_CONDITION_STR(cond_str) "[" cond_str "] "
 24#else
 25# define WARN_CONDITION_STR(cond_str)
 26#endif
 27#endif /* WARN_CONDITION_STR */
 28
 29#ifndef __ASSEMBLY__
 30#include <linux/panic.h>
 31#include <linux/printk.h>
 32
 33struct warn_args;
 34struct pt_regs;
 35
 36void __warn(const char *file, int line, void *caller, unsigned taint,
 37	    struct pt_regs *regs, struct warn_args *args);
 38
 39#ifdef CONFIG_BUG
 40
 41#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
 42#define BUG_REL(type, name) type name
 43#else
 44#define BUG_REL(type, name) signed int name##_disp
 45#endif
 46
 47#ifdef CONFIG_GENERIC_BUG
 48struct bug_entry {
 49	BUG_REL(unsigned long, bug_addr);
 50#ifdef HAVE_ARCH_BUG_FORMAT
 51	BUG_REL(const char *, format);
 52#endif
 53#ifdef CONFIG_DEBUG_BUGVERBOSE
 54	BUG_REL(const char *, file);
 55	unsigned short	line;
 56#endif
 57	unsigned short	flags;
 58};
 59#endif	/* CONFIG_GENERIC_BUG */
 60
 61/*
 62 * Don't use BUG() or BUG_ON() unless there's really no way out; one
 63 * example might be detecting data structure corruption in the middle
 64 * of an operation that can't be backed out of.  If the (sub)system
 65 * can somehow continue operating, perhaps with reduced functionality,
 66 * it's probably not BUG-worthy.
 67 *
 68 * If you're tempted to BUG(), think again:  is completely giving up
 69 * really the *only* solution?  There are usually better options, where
 70 * users don't need to reboot ASAP and can mostly shut down cleanly.
 71 */
 72#ifndef HAVE_ARCH_BUG
 73#define BUG() do { \
 74	printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
 75	barrier_before_unreachable(); \
 76	panic("BUG!"); \
 77} while (0)
 78#endif
 79
 80#ifndef HAVE_ARCH_BUG_ON
 81#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
 82#endif
 83
 84/*
 85 * WARN(), WARN_ON(), WARN_ON_ONCE(), and so on can be used to report
 86 * significant kernel issues that need prompt attention if they should ever
 87 * appear at runtime.
 88 *
 89 * Do not use these macros when checking for invalid external inputs
 90 * (e.g. invalid system call arguments, or invalid data coming from
 91 * network/devices), and on transient conditions like ENOMEM or EAGAIN.
 92 * These macros should be used for recoverable kernel issues only.
 93 * For invalid external inputs, transient conditions, etc use
 94 * pr_err[_once/_ratelimited]() followed by dump_stack(), if necessary.
 95 * Do not include "BUG"/"WARNING" in format strings manually to make these
 96 * conditions distinguishable from kernel issues.
 97 *
 98 * Use the versions with printk format strings to provide better diagnostics.
 99 */
100extern __printf(4, 5)
101void warn_slowpath_fmt(const char *file, const int line, unsigned taint,
102		       const char *fmt, ...);
103extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
104
105#ifdef __WARN_FLAGS
106#define __WARN()		__WARN_FLAGS("", BUGFLAG_TAINT(TAINT_WARN))
107
108#ifndef WARN_ON
109#define WARN_ON(condition) ({						\
110	int __ret_warn_on = !!(condition);				\
111	if (unlikely(__ret_warn_on))					\
112		__WARN_FLAGS(#condition,				\
113			     BUGFLAG_TAINT(TAINT_WARN));		\
114	unlikely(__ret_warn_on);					\
115})
116#endif
117
118#ifndef WARN_ON_ONCE
119#define WARN_ON_ONCE(condition) ({					\
120	int __ret_warn_on = !!(condition);				\
121	if (unlikely(__ret_warn_on))					\
122		__WARN_FLAGS(#condition,				\
123			     BUGFLAG_ONCE |				\
124			     BUGFLAG_TAINT(TAINT_WARN));		\
125	unlikely(__ret_warn_on);					\
126})
127#endif
128#endif /* __WARN_FLAGS */
129
130#if defined(__WARN_FLAGS) && !defined(__WARN_printf)
131#define __WARN_printf(taint, arg...) do {				\
132		instrumentation_begin();				\
133		__warn_printk(arg);					\
134		__WARN_FLAGS("", BUGFLAG_NO_CUT_HERE | BUGFLAG_TAINT(taint));\
135		instrumentation_end();					\
136	} while (0)
137#endif
138
139#ifndef __WARN_printf
140#define __WARN_printf(taint, arg...) do {				\
141		instrumentation_begin();				\
142		warn_slowpath_fmt(__FILE__, __LINE__, taint, arg);	\
143		instrumentation_end();					\
144	} while (0)
145#endif
146
147#ifndef __WARN
148#define __WARN()		__WARN_printf(TAINT_WARN, NULL)
149#endif
150
151/* used internally by panic.c */
152
153#ifndef WARN_ON
154#define WARN_ON(condition) ({						\
155	int __ret_warn_on = !!(condition);				\
156	if (unlikely(__ret_warn_on))					\
157		__WARN();						\
158	unlikely(__ret_warn_on);					\
159})
160#endif
161
162#ifndef WARN
163#define WARN(condition, format...) ({					\
164	int __ret_warn_on = !!(condition);				\
165	if (unlikely(__ret_warn_on))					\
166		__WARN_printf(TAINT_WARN, format);			\
167	unlikely(__ret_warn_on);					\
168})
169#endif
170
171#define WARN_TAINT(condition, taint, format...) ({			\
172	int __ret_warn_on = !!(condition);				\
173	if (unlikely(__ret_warn_on))					\
174		__WARN_printf(taint, format);				\
175	unlikely(__ret_warn_on);					\
176})
177
178#ifndef WARN_ON_ONCE
179#define WARN_ON_ONCE(condition)					\
180	DO_ONCE_LITE_IF(condition, WARN_ON, 1)
181#endif
182
183#ifndef WARN_ONCE
184#define WARN_ONCE(condition, format...)				\
185	DO_ONCE_LITE_IF(condition, WARN, 1, format)
186#endif
187
188#define WARN_TAINT_ONCE(condition, taint, format...)		\
189	DO_ONCE_LITE_IF(condition, WARN_TAINT, 1, taint, format)
190
191#else /* !CONFIG_BUG */
192#ifndef HAVE_ARCH_BUG
193#define BUG() do {		\
194	do {} while (1);	\
195	unreachable();		\
196} while (0)
197#endif
198
199#ifndef HAVE_ARCH_BUG_ON
200#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
201#endif
202
203#ifndef HAVE_ARCH_WARN_ON
204#define WARN_ON(condition) ({						\
205	int __ret_warn_on = !!(condition);				\
206	unlikely(__ret_warn_on);					\
207})
208#endif
209
210#ifndef WARN
211#define WARN(condition, format...) ({					\
212	int __ret_warn_on = !!(condition);				\
213	no_printk(format);						\
214	unlikely(__ret_warn_on);					\
215})
216#endif
217
218#define WARN_ON_ONCE(condition) WARN_ON(condition)
219#define WARN_ONCE(condition, format...) WARN(condition, format)
220#define WARN_TAINT(condition, taint, format...) WARN(condition, format)
221#define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
222
223#endif
224
225/*
226 * WARN_ON_SMP() is for cases that the warning is either
227 * meaningless for !SMP or may even cause failures.
228 * It can also be used with values that are only defined
229 * on SMP:
230 *
231 * struct foo {
232 *  [...]
233 * #ifdef CONFIG_SMP
234 *	int bar;
235 * #endif
236 * };
237 *
238 * void func(struct foo *zoot)
239 * {
240 *	WARN_ON_SMP(!zoot->bar);
241 *
242 * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
243 * and should be a nop and return false for uniprocessor.
244 *
245 * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
246 * and x is true.
247 */
248#ifdef CONFIG_SMP
249# define WARN_ON_SMP(x)			WARN_ON(x)
250#else
251/*
252 * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
253 * a stand alone line statement or as a condition in an if ()
254 * statement.
255 * A simple "0" would cause gcc to give a "statement has no effect"
256 * warning.
257 */
258# define WARN_ON_SMP(x)			({0;})
259#endif
260
261#endif /* __ASSEMBLY__ */
262
263#endif