xref: /openbmc/linux/arch/riscv/include/asm/ptrace.h (revision 63705da3)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012 Regents of the University of California
4  */
5 
6 #ifndef _ASM_RISCV_PTRACE_H
7 #define _ASM_RISCV_PTRACE_H
8 
9 #include <uapi/asm/ptrace.h>
10 #include <asm/csr.h>
11 #include <linux/compiler.h>
12 
13 #ifndef __ASSEMBLY__
14 
15 struct pt_regs {
16 	unsigned long epc;
17 	unsigned long ra;
18 	unsigned long sp;
19 	unsigned long gp;
20 	unsigned long tp;
21 	unsigned long t0;
22 	unsigned long t1;
23 	unsigned long t2;
24 	unsigned long s0;
25 	unsigned long s1;
26 	unsigned long a0;
27 	unsigned long a1;
28 	unsigned long a2;
29 	unsigned long a3;
30 	unsigned long a4;
31 	unsigned long a5;
32 	unsigned long a6;
33 	unsigned long a7;
34 	unsigned long s2;
35 	unsigned long s3;
36 	unsigned long s4;
37 	unsigned long s5;
38 	unsigned long s6;
39 	unsigned long s7;
40 	unsigned long s8;
41 	unsigned long s9;
42 	unsigned long s10;
43 	unsigned long s11;
44 	unsigned long t3;
45 	unsigned long t4;
46 	unsigned long t5;
47 	unsigned long t6;
48 	/* Supervisor/Machine CSRs */
49 	unsigned long status;
50 	unsigned long badaddr;
51 	unsigned long cause;
52 	/* a0 value before the syscall */
53 	unsigned long orig_a0;
54 };
55 
56 #ifdef CONFIG_64BIT
57 #define REG_FMT "%016lx"
58 #else
59 #define REG_FMT "%08lx"
60 #endif
61 
62 #define user_mode(regs) (((regs)->status & SR_PP) == 0)
63 
64 #define MAX_REG_OFFSET offsetof(struct pt_regs, orig_a0)
65 
66 /* Helpers for working with the instruction pointer */
67 static inline unsigned long instruction_pointer(struct pt_regs *regs)
68 {
69 	return regs->epc;
70 }
71 static inline void instruction_pointer_set(struct pt_regs *regs,
72 					   unsigned long val)
73 {
74 	regs->epc = val;
75 }
76 
77 #define profile_pc(regs) instruction_pointer(regs)
78 
79 /* Helpers for working with the user stack pointer */
80 static inline unsigned long user_stack_pointer(struct pt_regs *regs)
81 {
82 	return regs->sp;
83 }
84 static inline void user_stack_pointer_set(struct pt_regs *regs,
85 					  unsigned long val)
86 {
87 	regs->sp =  val;
88 }
89 
90 /* Valid only for Kernel mode traps. */
91 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
92 {
93 	return regs->sp;
94 }
95 
96 /* Helpers for working with the frame pointer */
97 static inline unsigned long frame_pointer(struct pt_regs *regs)
98 {
99 	return regs->s0;
100 }
101 static inline void frame_pointer_set(struct pt_regs *regs,
102 				     unsigned long val)
103 {
104 	regs->s0 = val;
105 }
106 
107 static inline unsigned long regs_return_value(struct pt_regs *regs)
108 {
109 	return regs->a0;
110 }
111 
112 static inline void regs_set_return_value(struct pt_regs *regs,
113 					 unsigned long val)
114 {
115 	regs->a0 = val;
116 }
117 
118 extern int regs_query_register_offset(const char *name);
119 extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
120 					       unsigned int n);
121 
122 void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
123 			   unsigned long frame_pointer);
124 int do_syscall_trace_enter(struct pt_regs *regs);
125 void do_syscall_trace_exit(struct pt_regs *regs);
126 
127 /**
128  * regs_get_register() - get register value from its offset
129  * @regs:	pt_regs from which register value is gotten
130  * @offset:	offset of the register.
131  *
132  * regs_get_register returns the value of a register whose offset from @regs.
133  * The @offset is the offset of the register in struct pt_regs.
134  * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
135  */
136 static inline unsigned long regs_get_register(struct pt_regs *regs,
137 					      unsigned int offset)
138 {
139 	if (unlikely(offset > MAX_REG_OFFSET))
140 		return 0;
141 
142 	return *(unsigned long *)((unsigned long)regs + offset);
143 }
144 
145 /**
146  * regs_get_kernel_argument() - get Nth function argument in kernel
147  * @regs:       pt_regs of that context
148  * @n:          function argument number (start from 0)
149  *
150  * regs_get_argument() returns @n th argument of the function call.
151  *
152  * Note you can get the parameter correctly if the function has no
153  * more than eight arguments.
154  */
155 static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
156 						unsigned int n)
157 {
158 	static const int nr_reg_arguments = 8;
159 	static const unsigned int argument_offs[] = {
160 		offsetof(struct pt_regs, a0),
161 		offsetof(struct pt_regs, a1),
162 		offsetof(struct pt_regs, a2),
163 		offsetof(struct pt_regs, a3),
164 		offsetof(struct pt_regs, a4),
165 		offsetof(struct pt_regs, a5),
166 		offsetof(struct pt_regs, a6),
167 		offsetof(struct pt_regs, a7),
168 	};
169 
170 	if (n < nr_reg_arguments)
171 		return regs_get_register(regs, argument_offs[n]);
172 	return 0;
173 }
174 
175 #endif /* __ASSEMBLY__ */
176 
177 #endif /* _ASM_RISCV_PTRACE_H */
178