Linux-2.6.12-rc2
[linux-3.10.git] / arch / h8300 / kernel / ptrace.c
1 /*
2  *  linux/arch/h8300/kernel/ptrace.c
3  *
4  *  Yoshinori Sato <ysato@users.sourceforge.jp>
5  *
6  *  Based on:
7  *  linux/arch/m68k/kernel/ptrace.c
8  *
9  *  Copyright (C) 1994 by Hamish Macdonald
10  *  Taken from linux/kernel/ptrace.c and modified for M680x0.
11  *  linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
12  *
13  * This file is subject to the terms and conditions of the GNU General
14  * Public License.  See the file COPYING in the main directory of
15  * this archive for more details.
16  */
17
18 #include <linux/kernel.h>
19 #include <linux/sched.h>
20 #include <linux/mm.h>
21 #include <linux/smp.h>
22 #include <linux/smp_lock.h>
23 #include <linux/errno.h>
24 #include <linux/ptrace.h>
25 #include <linux/user.h>
26 #include <linux/config.h>
27
28 #include <asm/uaccess.h>
29 #include <asm/page.h>
30 #include <asm/pgtable.h>
31 #include <asm/system.h>
32 #include <asm/processor.h>
33 #include <asm/signal.h>
34
35 /* cpu depend functions */
36 extern long h8300_get_reg(struct task_struct *task, int regno);
37 extern int  h8300_put_reg(struct task_struct *task, int regno, unsigned long data);
38 extern void h8300_disable_trace(struct task_struct *child);
39 extern void h8300_enable_trace(struct task_struct *child);
40
41 /*
42  * does not yet catch signals sent when the child dies.
43  * in exit.c or in signal.c.
44  */
45
46 inline
47 static int read_long(struct task_struct * tsk, unsigned long addr,
48         unsigned long * result)
49 {
50         *result = *(unsigned long *)addr;
51         return 0;
52 }
53
54 void ptrace_disable(struct task_struct *child)
55 {
56         h8300_disable_trace(child);
57 }
58
59 asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
60 {
61         struct task_struct *child;
62         int ret;
63
64         lock_kernel();
65         ret = -EPERM;
66         if (request == PTRACE_TRACEME) {
67                 /* are we already being traced? */
68                 if (current->ptrace & PT_PTRACED)
69                         goto out;
70                 /* set the ptrace bit in the process flags. */
71                 current->ptrace |= PT_PTRACED;
72                 ret = 0;
73                 goto out;
74         }
75         ret = -ESRCH;
76         read_lock(&tasklist_lock);
77         child = find_task_by_pid(pid);
78         if (child)
79                 get_task_struct(child);
80         read_unlock(&tasklist_lock);
81         if (!child)
82                 goto out;
83
84         ret = -EPERM;
85         if (pid == 1)           /* you may not mess with init */
86                 goto out_tsk;
87
88         if (request == PTRACE_ATTACH) {
89                 ret = ptrace_attach(child);
90                 goto out_tsk;
91         }
92         ret = ptrace_check_attach(child, request == PTRACE_KILL);
93         if (ret < 0)
94                 goto out_tsk;
95
96         switch (request) {
97                 case PTRACE_PEEKTEXT: /* read word at location addr. */ 
98                 case PTRACE_PEEKDATA: {
99                         unsigned long tmp;
100
101                         ret = read_long(child, addr, &tmp);
102                         if (ret < 0)
103                                 break ;
104                         ret = put_user(tmp, (unsigned long *) data);
105                         break ;
106                 }
107
108         /* read the word at location addr in the USER area. */
109                 case PTRACE_PEEKUSR: {
110                         unsigned long tmp = 0;
111                         
112                         if ((addr & 3) || addr < 0 || addr >= sizeof(struct user)) {
113                                 ret = -EIO;
114                                 break ;
115                         }
116                         
117                         ret = 0;  /* Default return condition */
118                         addr = addr >> 2; /* temporary hack. */
119
120                         if (addr < H8300_REGS_NO)
121                                 tmp = h8300_get_reg(child, addr);
122                         else {
123                                 switch(addr) {
124                                 case 49:
125                                         tmp = child->mm->start_code;
126                                         break ;
127                                 case 50:
128                                         tmp = child->mm->start_data;
129                                         break ;
130                                 case 51:
131                                         tmp = child->mm->end_code;
132                                         break ;
133                                 case 52:
134                                         tmp = child->mm->end_data;
135                                         break ;
136                                 default:
137                                         ret = -EIO;
138                                 }
139                         }
140                         if (!ret)
141                                 ret = put_user(tmp,(unsigned long *) data);
142                         break ;
143                 }
144
145       /* when I and D space are separate, this will have to be fixed. */
146                 case PTRACE_POKETEXT: /* write the word at location addr. */
147                 case PTRACE_POKEDATA:
148                         ret = 0;
149                         if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
150                                 break;
151                         ret = -EIO;
152                         break;
153
154                 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
155                         if ((addr & 3) || addr < 0 || addr >= sizeof(struct user)) {
156                                 ret = -EIO;
157                                 break ;
158                         }
159                         addr = addr >> 2; /* temporary hack. */
160                             
161                         if (addr == PT_ORIG_ER0) {
162                                 ret = -EIO;
163                                 break ;
164                         }
165                         if (addr < H8300_REGS_NO) {
166                                 ret = h8300_put_reg(child, addr, data);
167                                 break ;
168                         }
169                         ret = -EIO;
170                         break ;
171                 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
172                 case PTRACE_CONT: { /* restart after signal. */
173                         ret = -EIO;
174                         if ((unsigned long) data >= _NSIG)
175                                 break ;
176                         if (request == PTRACE_SYSCALL)
177                                 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
178                         else
179                                 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
180                         child->exit_code = data;
181                         wake_up_process(child);
182                         /* make sure the single step bit is not set. */
183                         h8300_disable_trace(child);
184                         ret = 0;
185                 }
186
187 /*
188  * make the child exit.  Best I can do is send it a sigkill. 
189  * perhaps it should be put in the status that it wants to 
190  * exit.
191  */
192                 case PTRACE_KILL: {
193
194                         ret = 0;
195                         if (child->exit_state == EXIT_ZOMBIE) /* already dead */
196                                 break;
197                         child->exit_code = SIGKILL;
198                         h8300_disable_trace(child);
199                         wake_up_process(child);
200                         break;
201                 }
202
203                 case PTRACE_SINGLESTEP: {  /* set the trap flag. */
204                         ret = -EIO;
205                         if ((unsigned long) data > _NSIG)
206                                 break;
207                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
208                         child->exit_code = data;
209                         h8300_enable_trace(child);
210                         wake_up_process(child);
211                         ret = 0;
212                         break;
213                 }
214
215                 case PTRACE_DETACH:     /* detach a process that was attached. */
216                         ret = ptrace_detach(child, data);
217                         break;
218
219                 case PTRACE_GETREGS: { /* Get all gp regs from the child. */
220                         int i;
221                         unsigned long tmp;
222                         for (i = 0; i < H8300_REGS_NO; i++) {
223                             tmp = h8300_get_reg(child, i);
224                             if (put_user(tmp, (unsigned long *) data)) {
225                                 ret = -EFAULT;
226                                 break;
227                             }
228                             data += sizeof(long);
229                         }
230                         ret = 0;
231                         break;
232                 }
233
234                 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
235                         int i;
236                         unsigned long tmp;
237                         for (i = 0; i < H8300_REGS_NO; i++) {
238                             if (get_user(tmp, (unsigned long *) data)) {
239                                 ret = -EFAULT;
240                                 break;
241                             }
242                             h8300_put_reg(child, i, tmp);
243                             data += sizeof(long);
244                         }
245                         ret = 0;
246                         break;
247                 }
248
249                 default:
250                         ret = -EIO;
251                         break;
252         }
253 out_tsk:
254         put_task_struct(child);
255 out:
256         unlock_kernel();
257         return ret;
258 }
259
260 asmlinkage void syscall_trace(void)
261 {
262         if (!test_thread_flag(TIF_SYSCALL_TRACE))
263                 return;
264         if (!(current->ptrace & PT_PTRACED))
265                 return;
266         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
267                                  ? 0x80 : 0));
268         /*
269          * this isn't the same as continuing with a signal, but it will do
270          * for normal use.  strace only continues with a signal if the
271          * stopping signal is not SIGTRAP.  -brl
272          */
273         if (current->exit_code) {
274                 send_sig(current->exit_code, current, 1);
275                 current->exit_code = 0;
276         }
277 }