1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * OpenRISC Linux
4 *
5 * Linux architectural port borrowing liberally from similar works of
6 * others. All original copyrights apply as per the original source
7 * declaration.
8 *
9 * OpenRISC implementation:
10 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
11 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
12 * et al.
13 */
14 #ifndef __ASM_OPENRISC_PTRACE_H
15 #define __ASM_OPENRISC_PTRACE_H
16
17
18 #include <asm/spr_defs.h>
19 #include <uapi/asm/ptrace.h>
20 #include <linux/compiler.h>
21
22 /*
23 * Make kernel PTrace/register structures opaque to userspace... userspace can
24 * access thread state via the regset mechanism. This allows us a bit of
25 * flexibility in how we order the registers on the stack, permitting some
26 * optimizations like packing call-clobbered registers together so that
27 * they share a cacheline (not done yet, though... future optimization).
28 */
29
30 #ifndef __ASSEMBLY__
31 /*
32 * This struct describes how the registers are laid out on the kernel stack
33 * during a syscall or other kernel entry.
34 *
35 * This structure should always be cacheline aligned on the stack.
36 * FIXME: I don't think that's the case right now. The alignment is
37 * taken care of elsewhere... head.S, process.c, etc.
38 */
39
40 struct pt_regs {
41 union {
42 struct {
43 /* Named registers */
44 long sr; /* Stored in place of r0 */
45 long sp; /* r1 */
46 long gpr2;
47 long gpr3;
48 long gpr4;
49 long gpr5;
50 long gpr6;
51 long gpr7;
52 long gpr8;
53 long gpr9;
54 long gpr10;
55 long gpr11;
56 long gpr12;
57 long gpr13;
58 long gpr14;
59 long gpr15;
60 long gpr16;
61 long gpr17;
62 long gpr18;
63 long gpr19;
64 long gpr20;
65 long gpr21;
66 long gpr22;
67 long gpr23;
68 long gpr24;
69 long gpr25;
70 long gpr26;
71 long gpr27;
72 long gpr28;
73 long gpr29;
74 long gpr30;
75 long gpr31;
76 };
77 struct {
78 /* Old style */
79 long offset[2];
80 long gprs[30];
81 };
82 struct {
83 /* New style */
84 long gpr[32];
85 };
86 };
87 long pc;
88 /* For restarting system calls:
89 * Set to syscall number for syscall exceptions,
90 * -1 for all other exceptions.
91 */
92 long orig_gpr11; /* For restarting system calls */
93 long dummy; /* Cheap alignment fix */
94 long dummy2; /* Cheap alignment fix */
95 };
96
97 /* TODO: Rename this to REDZONE because that's what it is */
98 #define STACK_FRAME_OVERHEAD 128 /* size of minimum stack frame */
99
100 #define MAX_REG_OFFSET offsetof(struct pt_regs, orig_gpr11)
101
102 /* Helpers for working with the instruction pointer */
instruction_pointer(struct pt_regs * regs)103 static inline unsigned long instruction_pointer(struct pt_regs *regs)
104 {
105 return (unsigned long)regs->pc;
106 }
instruction_pointer_set(struct pt_regs * regs,unsigned long val)107 static inline void instruction_pointer_set(struct pt_regs *regs,
108 unsigned long val)
109 {
110 regs->pc = val;
111 }
112
113 #define user_mode(regs) (((regs)->sr & SPR_SR_SM) == 0)
114 #define user_stack_pointer(regs) ((unsigned long)(regs)->sp)
115 #define profile_pc(regs) instruction_pointer(regs)
116
117 /* Valid only for Kernel mode traps. */
kernel_stack_pointer(struct pt_regs * regs)118 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
119 {
120 return (unsigned long)regs->sp;
121 }
122
regs_return_value(struct pt_regs * regs)123 static inline long regs_return_value(struct pt_regs *regs)
124 {
125 return regs->gpr[11];
126 }
127
128 extern int regs_query_register_offset(const char *name);
129 extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
130 unsigned int n);
131
132 /**
133 * regs_get_register() - get register value from its offset
134 * @regs: pt_regs from which register value is gotten
135 * @offset: offset of the register.
136 *
137 * regs_get_register returns the value of a register whose offset from @regs.
138 * The @offset is the offset of the register in struct pt_regs.
139 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
140 */
regs_get_register(struct pt_regs * regs,unsigned int offset)141 static inline unsigned long regs_get_register(struct pt_regs *regs,
142 unsigned int offset)
143 {
144 if (unlikely(offset > MAX_REG_OFFSET))
145 return 0;
146
147 return *(unsigned long *)((unsigned long)regs + offset);
148 }
149
150 #endif /* __ASSEMBLY__ */
151
152 /*
153 * Offsets used by 'ptrace' system call interface.
154 */
155 #define PT_SR 0
156 #define PT_SP 4
157 #define PT_GPR2 8
158 #define PT_GPR3 12
159 #define PT_GPR4 16
160 #define PT_GPR5 20
161 #define PT_GPR6 24
162 #define PT_GPR7 28
163 #define PT_GPR8 32
164 #define PT_GPR9 36
165 #define PT_GPR10 40
166 #define PT_GPR11 44
167 #define PT_GPR12 48
168 #define PT_GPR13 52
169 #define PT_GPR14 56
170 #define PT_GPR15 60
171 #define PT_GPR16 64
172 #define PT_GPR17 68
173 #define PT_GPR18 72
174 #define PT_GPR19 76
175 #define PT_GPR20 80
176 #define PT_GPR21 84
177 #define PT_GPR22 88
178 #define PT_GPR23 92
179 #define PT_GPR24 96
180 #define PT_GPR25 100
181 #define PT_GPR26 104
182 #define PT_GPR27 108
183 #define PT_GPR28 112
184 #define PT_GPR29 116
185 #define PT_GPR30 120
186 #define PT_GPR31 124
187 #define PT_PC 128
188 #define PT_ORIG_GPR11 132
189
190 #endif /* __ASM_OPENRISC_PTRACE_H */
191