linux/include/asm-generic/bug.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_GENERIC_BUG_H
#define _ASM_GENERIC_BUG_H

#include <linux/compiler.h>
#include <linux/instrumentation.h>
#include <linux/once_lite.h>

#define CUT_HERE …

#ifdef CONFIG_GENERIC_BUG
#define BUGFLAG_WARNING …
#define BUGFLAG_ONCE …
#define BUGFLAG_DONE …
#define BUGFLAG_NO_CUT_HERE …
#define BUGFLAG_TAINT(taint) …
#define BUG_GET_TAINT(bug) …
#endif

#ifndef __ASSEMBLY__
#include <linux/panic.h>
#include <linux/printk.h>

struct warn_args;
struct pt_regs;

void __warn(const char *file, int line, void *caller, unsigned taint,
	    struct pt_regs *regs, struct warn_args *args);

#ifdef CONFIG_BUG

#ifdef CONFIG_GENERIC_BUG
struct bug_entry { … };
#endif	/* CONFIG_GENERIC_BUG */

/*
 * Don't use BUG() or BUG_ON() unless there's really no way out; one
 * example might be detecting data structure corruption in the middle
 * of an operation that can't be backed out of.  If the (sub)system
 * can somehow continue operating, perhaps with reduced functionality,
 * it's probably not BUG-worthy.
 *
 * If you're tempted to BUG(), think again:  is completely giving up
 * really the *only* solution?  There are usually better options, where
 * users don't need to reboot ASAP and can mostly shut down cleanly.
 */
#ifndef HAVE_ARCH_BUG
#define BUG …
#endif

#ifndef HAVE_ARCH_BUG_ON
#define BUG_ON(condition) …
#endif

/*
 * WARN(), WARN_ON(), WARN_ON_ONCE(), and so on can be used to report
 * significant kernel issues that need prompt attention if they should ever
 * appear at runtime.
 *
 * Do not use these macros when checking for invalid external inputs
 * (e.g. invalid system call arguments, or invalid data coming from
 * network/devices), and on transient conditions like ENOMEM or EAGAIN.
 * These macros should be used for recoverable kernel issues only.
 * For invalid external inputs, transient conditions, etc use
 * pr_err[_once/_ratelimited]() followed by dump_stack(), if necessary.
 * Do not include "BUG"/"WARNING" in format strings manually to make these
 * conditions distinguishable from kernel issues.
 *
 * Use the versions with printk format strings to provide better diagnostics.
 */
extern __printf(4, 5)
void warn_slowpath_fmt(const char *file, const int line, unsigned taint,
		       const char *fmt, ...);
extern __printf(1, 2) void __warn_printk(const char *fmt, ...);

#ifndef __WARN_FLAGS
#define __WARN …
#define __WARN_printf …
#else
#define __WARN() …
#define __WARN_printf(taint, arg...) …
#define WARN_ON_ONCE(condition) …
#endif

/* used internally by panic.c */

#ifndef WARN_ON
#define WARN_ON(condition) …
#endif

#ifndef WARN
#define WARN(condition, format...) …
#endif

#define WARN_TAINT(condition, taint, format...) …

#ifndef WARN_ON_ONCE
#define WARN_ON_ONCE …
#endif

#define WARN_ONCE(condition, format...) …

#define WARN_TAINT_ONCE(condition, taint, format...) …

#else /* !CONFIG_BUG */
#ifndef HAVE_ARCH_BUG
#define BUG …
#endif

#ifndef HAVE_ARCH_BUG_ON
#define BUG_ON …
#endif

#ifndef HAVE_ARCH_WARN_ON
#define WARN_ON …
#endif

#ifndef WARN
#define WARN …
#endif

#define WARN_ON_ONCE …
#define WARN_ONCE …
#define WARN_TAINT …
#define WARN_TAINT_ONCE …

#endif

/*
 * WARN_ON_SMP() is for cases that the warning is either
 * meaningless for !SMP or may even cause failures.
 * It can also be used with values that are only defined
 * on SMP:
 *
 * struct foo {
 *  [...]
 * #ifdef CONFIG_SMP
 *	int bar;
 * #endif
 * };
 *
 * void func(struct foo *zoot)
 * {
 *	WARN_ON_SMP(!zoot->bar);
 *
 * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
 * and should be a nop and return false for uniprocessor.
 *
 * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
 * and x is true.
 */
#ifdef CONFIG_SMP
#define WARN_ON_SMP(x) …
#else
/*
 * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
 * a stand alone line statement or as a condition in an if ()
 * statement.
 * A simple "0" would cause gcc to give a "statement has no effect"
 * warning.
 */
#define WARN_ON_SMP …
#endif

#endif /* __ASSEMBLY__ */

#endif