1 /*
2 * linux/arch/m68knommu/kernel/ptrace.c
3 *
4 * Copyright (C) 1994 by Hamish Macdonald
5 * Taken from linux/kernel/ptrace.c and modified for M680x0.
6 * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
7 *
8 * This file is subject to the terms and conditions of the GNU General
9 * Public License. See the file COPYING in the main directory of
10 * this archive for more details.
11 */
12
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/mm.h>
16 #include <linux/smp.h>
17 #include <linux/errno.h>
18 #include <linux/ptrace.h>
19 #include <linux/user.h>
20 #include <linux/signal.h>
21 #include <linux/tracehook.h>
22
23 #include <asm/uaccess.h>
24 #include <asm/page.h>
25 #include <asm/pgtable.h>
26 #include <asm/system.h>
27 #include <asm/processor.h>
28
29 /*
30 * does not yet catch signals sent when the child dies.
31 * in exit.c or in signal.c.
32 */
33
34 /* determines which bits in the SR the user has access to. */
35 /* 1 = access 0 = no access */
36 #define SR_MASK 0x001f
37
38 /* sets the trace bits. */
39 #define TRACE_BITS 0x8000
40
41 /* Find the stack offset for a register, relative to thread.esp0. */
42 #define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg)
43 #define SW_REG(reg) ((long)&((struct switch_stack *)0)->reg \
44 - sizeof(struct switch_stack))
45 /* Mapping from PT_xxx to the stack offset at which the register is
46 saved. Notice that usp has no stack-slot and needs to be treated
47 specially (see get_reg/put_reg below). */
48 static int regoff[] = {
49 PT_REG(d1), PT_REG(d2), PT_REG(d3), PT_REG(d4),
50 PT_REG(d5), SW_REG(d6), SW_REG(d7), PT_REG(a0),
51 PT_REG(a1), PT_REG(a2), SW_REG(a3), SW_REG(a4),
52 SW_REG(a5), SW_REG(a6), PT_REG(d0), -1,
53 PT_REG(orig_d0), PT_REG(sr), PT_REG(pc),
54 };
55
56 /*
57 * Get contents of register REGNO in task TASK.
58 */
get_reg(struct task_struct * task,int regno)59 static inline long get_reg(struct task_struct *task, int regno)
60 {
61 unsigned long *addr;
62
63 if (regno == PT_USP)
64 addr = &task->thread.usp;
65 else if (regno < ARRAY_SIZE(regoff))
66 addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
67 else
68 return 0;
69 return *addr;
70 }
71
72 /*
73 * Write contents of register REGNO in task TASK.
74 */
put_reg(struct task_struct * task,int regno,unsigned long data)75 static inline int put_reg(struct task_struct *task, int regno,
76 unsigned long data)
77 {
78 unsigned long *addr;
79
80 if (regno == PT_USP)
81 addr = &task->thread.usp;
82 else if (regno < ARRAY_SIZE(regoff))
83 addr = (unsigned long *) (task->thread.esp0 + regoff[regno]);
84 else
85 return -1;
86 *addr = data;
87 return 0;
88 }
89
user_enable_single_step(struct task_struct * task)90 void user_enable_single_step(struct task_struct *task)
91 {
92 unsigned long srflags;
93 srflags = get_reg(task, PT_SR) | (TRACE_BITS << 16);
94 put_reg(task, PT_SR, srflags);
95 }
96
user_disable_single_step(struct task_struct * task)97 void user_disable_single_step(struct task_struct *task)
98 {
99 unsigned long srflags;
100 srflags = get_reg(task, PT_SR) & ~(TRACE_BITS << 16);
101 put_reg(task, PT_SR, srflags);
102 }
103
104 /*
105 * Called by kernel/ptrace.c when detaching..
106 *
107 * Make sure the single step bit is not set.
108 */
ptrace_disable(struct task_struct * child)109 void ptrace_disable(struct task_struct *child)
110 {
111 /* make sure the single step bit is not set. */
112 user_disable_single_step(child);
113 }
114
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)115 long arch_ptrace(struct task_struct *child, long request,
116 unsigned long addr, unsigned long data)
117 {
118 int ret;
119 int regno = addr >> 2;
120 unsigned long __user *datap = (unsigned long __user *) data;
121
122 switch (request) {
123 /* read the word at location addr in the USER area. */
124 case PTRACE_PEEKUSR: {
125 unsigned long tmp;
126
127 ret = -EIO;
128 if ((addr & 3) || addr > sizeof(struct user) - 3)
129 break;
130
131 tmp = 0; /* Default return condition */
132 ret = -EIO;
133 if (regno < 19) {
134 tmp = get_reg(child, regno);
135 if (regno == PT_SR)
136 tmp >>= 16;
137 } else if (regno >= 21 && regno < 49) {
138 tmp = child->thread.fp[regno - 21];
139 } else if (regno == 49) {
140 tmp = child->mm->start_code;
141 } else if (regno == 50) {
142 tmp = child->mm->start_data;
143 } else if (regno == 51) {
144 tmp = child->mm->end_code;
145 } else
146 break;
147 ret = put_user(tmp, datap);
148 break;
149 }
150
151 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
152 ret = -EIO;
153 if ((addr & 3) || addr > sizeof(struct user) - 3)
154 break;
155
156 if (regno == PT_SR) {
157 data &= SR_MASK;
158 data <<= 16;
159 data |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
160 }
161 if (regno < 19) {
162 if (put_reg(child, regno, data))
163 break;
164 ret = 0;
165 break;
166 }
167 if (regno >= 21 && regno < 48)
168 {
169 child->thread.fp[regno - 21] = data;
170 ret = 0;
171 }
172 break;
173
174 case PTRACE_GETREGS: { /* Get all gp regs from the child. */
175 int i;
176 unsigned long tmp;
177 for (i = 0; i < 19; i++) {
178 tmp = get_reg(child, i);
179 if (i == PT_SR)
180 tmp >>= 16;
181 if (put_user(tmp, datap)) {
182 ret = -EFAULT;
183 break;
184 }
185 datap++;
186 }
187 ret = 0;
188 break;
189 }
190
191 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
192 int i;
193 unsigned long tmp;
194 for (i = 0; i < 19; i++) {
195 if (get_user(tmp, datap)) {
196 ret = -EFAULT;
197 break;
198 }
199 if (i == PT_SR) {
200 tmp &= SR_MASK;
201 tmp <<= 16;
202 tmp |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
203 }
204 put_reg(child, i, tmp);
205 datap++;
206 }
207 ret = 0;
208 break;
209 }
210
211 #ifdef PTRACE_GETFPREGS
212 case PTRACE_GETFPREGS: { /* Get the child FPU state. */
213 ret = 0;
214 if (copy_to_user(datap, &child->thread.fp,
215 sizeof(struct user_m68kfp_struct)))
216 ret = -EFAULT;
217 break;
218 }
219 #endif
220
221 #ifdef PTRACE_SETFPREGS
222 case PTRACE_SETFPREGS: { /* Set the child FPU state. */
223 ret = 0;
224 if (copy_from_user(&child->thread.fp, datap,
225 sizeof(struct user_m68kfp_struct)))
226 ret = -EFAULT;
227 break;
228 }
229 #endif
230
231 case PTRACE_GET_THREAD_AREA:
232 ret = put_user(task_thread_info(child)->tp_value, datap);
233 break;
234
235 default:
236 ret = ptrace_request(child, request, addr, data);
237 break;
238 }
239 return ret;
240 }
241
syscall_trace_enter(void)242 asmlinkage int syscall_trace_enter(void)
243 {
244 int ret = 0;
245
246 if (test_thread_flag(TIF_SYSCALL_TRACE))
247 ret = tracehook_report_syscall_entry(task_pt_regs(current));
248 return ret;
249 }
250
syscall_trace_leave(void)251 asmlinkage void syscall_trace_leave(void)
252 {
253 if (test_thread_flag(TIF_SYSCALL_TRACE))
254 tracehook_report_syscall_exit(task_pt_regs(current), 0);
255 }
256