xref: /openbmc/linux/arch/arm/include/asm/bug.h (revision be709d48)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASMARM_BUG_H
3 #define _ASMARM_BUG_H
4 
5 #include <linux/linkage.h>
6 #include <linux/types.h>
7 #include <asm/opcodes.h>
8 
9 /*
10  * Use a suitable undefined instruction to use for ARM/Thumb2 bug handling.
11  * We need to be careful not to conflict with those used by other modules and
12  * the register_undef_hook() system.
13  */
14 #ifdef CONFIG_THUMB2_KERNEL
15 #define BUG_INSTR_VALUE 0xde02
16 #define BUG_INSTR(__value) __inst_thumb16(__value)
17 #else
18 #define BUG_INSTR_VALUE 0xe7f001f2
19 #define BUG_INSTR(__value) __inst_arm(__value)
20 #endif
21 
22 
23 #define BUG() _BUG(__FILE__, __LINE__, BUG_INSTR_VALUE)
24 #define _BUG(file, line, value) __BUG(file, line, value)
25 
26 #ifdef CONFIG_DEBUG_BUGVERBOSE
27 
28 /*
29  * The extra indirection is to ensure that the __FILE__ string comes through
30  * OK. Many version of gcc do not support the asm %c parameter which would be
31  * preferable to this unpleasantness. We use mergeable string sections to
32  * avoid multiple copies of the string appearing in the kernel image.
33  */
34 
35 #define __BUG(__file, __line, __value)				\
36 do {								\
37 	asm volatile("1:\t" BUG_INSTR(__value) "\n"  \
38 		".pushsection .rodata.str, \"aMS\", %progbits, 1\n" \
39 		"2:\t.asciz " #__file "\n" 			\
40 		".popsection\n" 				\
41 		".pushsection __bug_table,\"aw\"\n"		\
42 		".align 2\n"					\
43 		"3:\t.word 1b, 2b\n"				\
44 		"\t.hword " #__line ", 0\n"			\
45 		".popsection");					\
46 	unreachable();						\
47 } while (0)
48 
49 #else
50 
51 #define __BUG(__file, __line, __value)				\
52 do {								\
53 	asm volatile(BUG_INSTR(__value) "\n");			\
54 	unreachable();						\
55 } while (0)
56 #endif  /* CONFIG_DEBUG_BUGVERBOSE */
57 
58 #define HAVE_ARCH_BUG
59 
60 #include <asm-generic/bug.h>
61 
62 struct pt_regs;
63 void die(const char *msg, struct pt_regs *regs, int err);
64 
65 void arm_notify_die(const char *str, struct pt_regs *regs,
66 		int signo, int si_code, void __user *addr,
67 		unsigned long err, unsigned long trap);
68 
69 #ifdef CONFIG_ARM_LPAE
70 #define FAULT_CODE_ALIGNMENT	33
71 #define FAULT_CODE_DEBUG	34
72 #else
73 #define FAULT_CODE_ALIGNMENT	1
74 #define FAULT_CODE_DEBUG	2
75 #endif
76 
77 void hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int,
78 				       struct pt_regs *),
79 		     int sig, int code, const char *name);
80 
81 void hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int,
82 				       struct pt_regs *),
83 		     int sig, int code, const char *name);
84 
85 extern asmlinkage void c_backtrace(unsigned long fp, int pmode);
86 
87 struct mm_struct;
88 extern void show_pte(struct mm_struct *mm, unsigned long addr);
89 extern void __show_regs(struct pt_regs *);
90 
91 #endif
92