xref: /openbmc/linux/arch/arm/include/asm/ptrace.h (revision 12eb4683)
1 /*
2  *  arch/arm/include/asm/ptrace.h
3  *
4  *  Copyright (C) 1996-2003 Russell King
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 #ifndef __ASM_ARM_PTRACE_H
11 #define __ASM_ARM_PTRACE_H
12 
13 #include <uapi/asm/ptrace.h>
14 
15 #ifndef __ASSEMBLY__
16 struct pt_regs {
17 	unsigned long uregs[18];
18 };
19 
20 #define user_mode(regs)	\
21 	(((regs)->ARM_cpsr & 0xf) == 0)
22 
23 #ifdef CONFIG_ARM_THUMB
24 #define thumb_mode(regs) \
25 	(((regs)->ARM_cpsr & PSR_T_BIT))
26 #else
27 #define thumb_mode(regs) (0)
28 #endif
29 
30 #define isa_mode(regs) \
31 	((((regs)->ARM_cpsr & PSR_J_BIT) >> 23) | \
32 	 (((regs)->ARM_cpsr & PSR_T_BIT) >> 5))
33 
34 #define processor_mode(regs) \
35 	((regs)->ARM_cpsr & MODE_MASK)
36 
37 #define interrupts_enabled(regs) \
38 	(!((regs)->ARM_cpsr & PSR_I_BIT))
39 
40 #define fast_interrupts_enabled(regs) \
41 	(!((regs)->ARM_cpsr & PSR_F_BIT))
42 
43 /* Are the current registers suitable for user mode?
44  * (used to maintain security in signal handlers)
45  */
46 static inline int valid_user_regs(struct pt_regs *regs)
47 {
48 #ifndef CONFIG_CPU_V7M
49 	unsigned long mode = regs->ARM_cpsr & MODE_MASK;
50 
51 	/*
52 	 * Always clear the F (FIQ) and A (delayed abort) bits
53 	 */
54 	regs->ARM_cpsr &= ~(PSR_F_BIT | PSR_A_BIT);
55 
56 	if ((regs->ARM_cpsr & PSR_I_BIT) == 0) {
57 		if (mode == USR_MODE)
58 			return 1;
59 		if (elf_hwcap & HWCAP_26BIT && mode == USR26_MODE)
60 			return 1;
61 	}
62 
63 	/*
64 	 * Force CPSR to something logical...
65 	 */
66 	regs->ARM_cpsr &= PSR_f | PSR_s | PSR_x | PSR_T_BIT | MODE32_BIT;
67 	if (!(elf_hwcap & HWCAP_26BIT))
68 		regs->ARM_cpsr |= USR_MODE;
69 
70 	return 0;
71 #else /* ifndef CONFIG_CPU_V7M */
72 	return 1;
73 #endif
74 }
75 
76 static inline long regs_return_value(struct pt_regs *regs)
77 {
78 	return regs->ARM_r0;
79 }
80 
81 #define instruction_pointer(regs)	(regs)->ARM_pc
82 
83 #ifdef CONFIG_SMP
84 extern unsigned long profile_pc(struct pt_regs *regs);
85 #else
86 #define profile_pc(regs) instruction_pointer(regs)
87 #endif
88 
89 #define predicate(x)		((x) & 0xf0000000)
90 #define PREDICATE_ALWAYS	0xe0000000
91 
92 /*
93  * True if instr is a 32-bit thumb instruction. This works if instr
94  * is the first or only half-word of a thumb instruction. It also works
95  * when instr holds all 32-bits of a wide thumb instruction if stored
96  * in the form (first_half<<16)|(second_half)
97  */
98 #define is_wide_instruction(instr)	((unsigned)(instr) >= 0xe800)
99 
100 /*
101  * kprobe-based event tracer support
102  */
103 #include <linux/stddef.h>
104 #include <linux/types.h>
105 #define MAX_REG_OFFSET (offsetof(struct pt_regs, ARM_ORIG_r0))
106 
107 extern int regs_query_register_offset(const char *name);
108 extern const char *regs_query_register_name(unsigned int offset);
109 extern bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr);
110 extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
111 					       unsigned int n);
112 
113 /**
114  * regs_get_register() - get register value from its offset
115  * @regs:	   pt_regs from which register value is gotten
116  * @offset:    offset number of the register.
117  *
118  * regs_get_register returns the value of a register whose offset from @regs.
119  * The @offset is the offset of the register in struct pt_regs.
120  * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
121  */
122 static inline unsigned long regs_get_register(struct pt_regs *regs,
123 					      unsigned int offset)
124 {
125 	if (unlikely(offset > MAX_REG_OFFSET))
126 		return 0;
127 	return *(unsigned long *)((unsigned long)regs + offset);
128 }
129 
130 /* Valid only for Kernel mode traps. */
131 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
132 {
133 	return regs->ARM_sp;
134 }
135 
136 static inline unsigned long user_stack_pointer(struct pt_regs *regs)
137 {
138 	return regs->ARM_sp;
139 }
140 
141 #define current_pt_regs(void) ({				\
142 	register unsigned long sp asm ("sp");			\
143 	(struct pt_regs *)((sp | (THREAD_SIZE - 1)) - 7) - 1;	\
144 })
145 
146 #endif /* __ASSEMBLY__ */
147 #endif
148