forked from mirrors/linux
		
	Since BUG() and WARN() may use a trap (e.g. UD2 on x86) to get the address where the BUG() has occurred, kprobes can not do single-step out-of-line that instruction. So prohibit probing on such address. Without this fix, if someone put a kprobe on WARN(), the kernel will crash with invalid opcode error instead of outputing warning message, because kernel can not find correct bug address. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S . Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N . Rao <naveen.n.rao@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/156750890133.19112.3393666300746167111.stgit@devnote2 Signed-off-by: Ingo Molnar <mingo@kernel.org>
		
			
				
	
	
		
			84 lines
		
	
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			84 lines
		
	
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: GPL-2.0 */
 | 
						|
#ifndef _LINUX_BUG_H
 | 
						|
#define _LINUX_BUG_H
 | 
						|
 | 
						|
#include <asm/bug.h>
 | 
						|
#include <linux/compiler.h>
 | 
						|
#include <linux/build_bug.h>
 | 
						|
 | 
						|
enum bug_trap_type {
 | 
						|
	BUG_TRAP_TYPE_NONE = 0,
 | 
						|
	BUG_TRAP_TYPE_WARN = 1,
 | 
						|
	BUG_TRAP_TYPE_BUG = 2,
 | 
						|
};
 | 
						|
 | 
						|
struct pt_regs;
 | 
						|
 | 
						|
#ifdef __CHECKER__
 | 
						|
#define MAYBE_BUILD_BUG_ON(cond) (0)
 | 
						|
#else /* __CHECKER__ */
 | 
						|
 | 
						|
#define MAYBE_BUILD_BUG_ON(cond)			\
 | 
						|
	do {						\
 | 
						|
		if (__builtin_constant_p((cond)))       \
 | 
						|
			BUILD_BUG_ON(cond);             \
 | 
						|
		else                                    \
 | 
						|
			BUG_ON(cond);                   \
 | 
						|
	} while (0)
 | 
						|
 | 
						|
#endif	/* __CHECKER__ */
 | 
						|
 | 
						|
#ifdef CONFIG_GENERIC_BUG
 | 
						|
#include <asm-generic/bug.h>
 | 
						|
 | 
						|
static inline int is_warning_bug(const struct bug_entry *bug)
 | 
						|
{
 | 
						|
	return bug->flags & BUGFLAG_WARNING;
 | 
						|
}
 | 
						|
 | 
						|
struct bug_entry *find_bug(unsigned long bugaddr);
 | 
						|
 | 
						|
enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs);
 | 
						|
 | 
						|
/* These are defined by the architecture */
 | 
						|
int is_valid_bugaddr(unsigned long addr);
 | 
						|
 | 
						|
void generic_bug_clear_once(void);
 | 
						|
 | 
						|
#else	/* !CONFIG_GENERIC_BUG */
 | 
						|
 | 
						|
static inline void *find_bug(unsigned long bugaddr)
 | 
						|
{
 | 
						|
	return NULL;
 | 
						|
}
 | 
						|
 | 
						|
static inline enum bug_trap_type report_bug(unsigned long bug_addr,
 | 
						|
					    struct pt_regs *regs)
 | 
						|
{
 | 
						|
	return BUG_TRAP_TYPE_BUG;
 | 
						|
}
 | 
						|
 | 
						|
 | 
						|
static inline void generic_bug_clear_once(void) {}
 | 
						|
 | 
						|
#endif	/* CONFIG_GENERIC_BUG */
 | 
						|
 | 
						|
/*
 | 
						|
 * Since detected data corruption should stop operation on the affected
 | 
						|
 * structures. Return value must be checked and sanely acted on by caller.
 | 
						|
 */
 | 
						|
static inline __must_check bool check_data_corruption(bool v) { return v; }
 | 
						|
#define CHECK_DATA_CORRUPTION(condition, fmt, ...)			 \
 | 
						|
	check_data_corruption(({					 \
 | 
						|
		bool corruption = unlikely(condition);			 \
 | 
						|
		if (corruption) {					 \
 | 
						|
			if (IS_ENABLED(CONFIG_BUG_ON_DATA_CORRUPTION)) { \
 | 
						|
				pr_err(fmt, ##__VA_ARGS__);		 \
 | 
						|
				BUG();					 \
 | 
						|
			} else						 \
 | 
						|
				WARN(1, fmt, ##__VA_ARGS__);		 \
 | 
						|
		}							 \
 | 
						|
		corruption;						 \
 | 
						|
	}))
 | 
						|
 | 
						|
#endif	/* _LINUX_BUG_H */
 |