summaryrefslogtreecommitdiffstats
path: root/arch/h8300/kernel/ptrace.c
blob: 05c15e869777fc3225ca7fb400fb306556c5385f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
/*
 *  linux/arch/h8300/kernel/ptrace.c
 *
 *  Yoshinori Sato <ysato@users.sourceforge.jp>
 *
 *  Based on:
 *  linux/arch/m68k/kernel/ptrace.c
 *
 *  Copyright (C) 1994 by Hamish Macdonald
 *  Taken from linux/kernel/ptrace.c and modified for M680x0.
 *  linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License.  See the file COPYING in the main directory of
 * this archive for more details.
 */

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/config.h>
#include <linux/signal.h>

#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/signal.h>

/* cpu depend functions */
extern long h8300_get_reg(struct task_struct *task, int regno);
extern int  h8300_put_reg(struct task_struct *task, int regno, unsigned long data);
extern void h8300_disable_trace(struct task_struct *child);
extern void h8300_enable_trace(struct task_struct *child);

/*
 * does not yet catch signals sent when the child dies.
 * in exit.c or in signal.c.
 */

inline
static int read_long(struct task_struct * tsk, unsigned long addr,
	unsigned long * result)
{
	*result = *(unsigned long *)addr;
	return 0;
}

void ptrace_disable(struct task_struct *child)
{
	h8300_disable_trace(child);
}

asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
{
	struct task_struct *child;
	int ret;

	lock_kernel();
	ret = -EPERM;
	if (request == PTRACE_TRACEME) {
		/* are we already being traced? */
		if (current->ptrace & PT_PTRACED)
			goto out;
		/* set the ptrace bit in the process flags. */
		current->ptrace |= PT_PTRACED;
		ret = 0;
		goto out;
	}
	ret = -ESRCH;
	read_lock(&tasklist_lock);
	child = find_task_by_pid(pid);
	if (child)
		get_task_struct(child);
	read_unlock(&tasklist_lock);
	if (!child)
		goto out;

	ret = -EPERM;
	if (pid == 1)		/* you may not mess with init */
		goto out_tsk;

	if (request == PTRACE_ATTACH) {
		ret = ptrace_attach(child);
		goto out_tsk;
	}
	ret = ptrace_check_attach(child, request == PTRACE_KILL);
	if (ret < 0)
		goto out_tsk;

	switch (request) {
		case PTRACE_PEEKTEXT: /* read word at location addr. */ 
		case PTRACE_PEEKDATA: {
			unsigned long tmp;

			ret = read_long(child, addr, &tmp);
			if (ret < 0)
				break ;
			ret = put_user(tmp, (unsigned long *) data);
			break ;
		}

	/* read the word at location addr in the USER area. */
		case PTRACE_PEEKUSR: {
			unsigned long tmp = 0;
			
			if ((addr & 3) || addr < 0 || addr >= sizeof(struct user)) {
				ret = -EIO;
				break ;
			}
			
		        ret = 0;  /* Default return condition */
			addr = addr >> 2; /* temporary hack. */

			if (addr < H8300_REGS_NO)
				tmp = h8300_get_reg(child, addr);
			else {
				switch(addr) {
				case 49:
					tmp = child->mm->start_code;
					break ;
				case 50:
					tmp = child->mm->start_data;
					break ;
				case 51:
					tmp = child->mm->end_code;
					break ;
				case 52:
					tmp = child->mm->end_data;
					break ;
				default:
					ret = -EIO;
				}
			}
			if (!ret)
				ret = put_user(tmp,(unsigned long *) data);
			break ;
		}

      /* when I and D space are separate, this will have to be fixed. */
		case PTRACE_POKETEXT: /* write the word at location addr. */
		case PTRACE_POKEDATA:
			ret = 0;
			if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
				break;
			ret = -EIO;
			break;

		case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
			if ((addr & 3) || addr < 0 || addr >= sizeof(struct user)) {
				ret = -EIO;
				break ;
			}
			addr = addr >> 2; /* temporary hack. */
			    
			if (addr == PT_ORIG_ER0) {
				ret = -EIO;
				break ;
			}
			if (addr < H8300_REGS_NO) {
				ret = h8300_put_reg(child, addr, data);
				break ;
			}
			ret = -EIO;
			break ;
		case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
		case PTRACE_CONT: { /* restart after signal. */
			ret = -EIO;
			if (!valid_signal(data))
				break ;
			if (request == PTRACE_SYSCALL)
				set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
			else
				clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
			child->exit_code = data;
			wake_up_process(child);
			/* make sure the single step bit is not set. */
			h8300_disable_trace(child);
			ret = 0;
		}

/*
 * make the child exit.  Best I can do is send it a sigkill. 
 * perhaps it should be put in the status that it wants to 
 * exit.
 */
		case PTRACE_KILL: {

			ret = 0;
			if (child->exit_state == EXIT_ZOMBIE) /* already dead */
				break;
			child->exit_code = SIGKILL;
			h8300_disable_trace(child);
			wake_up_process(child);
			break;
		}

		case PTRACE_SINGLESTEP: {  /* set the trap flag. */
			ret = -EIO;
			if (!valid_signal(data))
				break;
			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
			child->exit_code = data;
			h8300_enable_trace(child);
			wake_up_process(child);
			ret = 0;
			break;
		}

		case PTRACE_DETACH:	/* detach a process that was attached. */
			ret = ptrace_detach(child, data);
			break;

		case PTRACE_GETREGS: { /* Get all gp regs from the child. */
		  	int i;
			unsigned long tmp;
			for (i = 0; i < H8300_REGS_NO; i++) {
			    tmp = h8300_get_reg(child, i);
			    if (put_user(tmp, (unsigned long *) data)) {
				ret = -EFAULT;
				break;
			    }
			    data += sizeof(long);
			}
			ret = 0;
			break;
		}

		case PTRACE_SETREGS: { /* Set all gp regs in the child. */
			int i;
			unsigned long tmp;
			for (i = 0; i < H8300_REGS_NO; i++) {
			    if (get_user(tmp, (unsigned long *) data)) {
				ret = -EFAULT;
				break;
			    }
			    h8300_put_reg(child, i, tmp);
			    data += sizeof(long);
			}
			ret = 0;
			break;
		}

		default:
			ret = -EIO;
			break;
	}
out_tsk:
	put_task_struct(child);
out:
	unlock_kernel();
	return ret;
}

asmlinkage void syscall_trace(void)
{
	if (!test_thread_flag(TIF_SYSCALL_TRACE))
		return;
	if (!(current->ptrace & PT_PTRACED))
		return;
	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
				 ? 0x80 : 0));
	/*
	 * this isn't the same as continuing with a signal, but it will do
	 * for normal use.  strace only continues with a signal if the
	 * stopping signal is not SIGTRAP.  -brl
	 */
	if (current->exit_code) {
		send_sig(current->exit_code, current, 1);
		current->exit_code = 0;
	}
}
OpenPOWER on IntegriCloud