9130119537b9ffdbe082e9857f0ea9c657ae159b
[sfrench/cifs-2.6.git] / arch / m68knommu / kernel / ptrace.c
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/smp_lock.h>
18 #include <linux/errno.h>
19 #include <linux/ptrace.h>
20 #include <linux/user.h>
21 #include <linux/signal.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  */
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 < sizeof(regoff)/sizeof(regoff[0]))
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  */
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 < sizeof(regoff)/sizeof(regoff[0]))
83                 addr = (unsigned long *) (task->thread.esp0 + regoff[regno]);
84         else
85                 return -1;
86         *addr = data;
87         return 0;
88 }
89
90 /*
91  * Called by kernel/ptrace.c when detaching..
92  *
93  * Make sure the single step bit is not set.
94  */
95 void ptrace_disable(struct task_struct *child)
96 {
97         unsigned long tmp;
98         /* make sure the single step bit is not set. */
99         tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
100         put_reg(child, PT_SR, tmp);
101 }
102
103 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
104 {
105         int ret;
106
107         switch (request) {
108                 /* when I and D space are separate, these will need to be fixed. */
109                 case PTRACE_PEEKTEXT: /* read word at location addr. */ 
110                 case PTRACE_PEEKDATA: {
111                         unsigned long tmp;
112                         int copied;
113
114                         copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
115                         ret = -EIO;
116                         if (copied != sizeof(tmp))
117                                 break;
118                         ret = put_user(tmp,(unsigned long *) data);
119                         break;
120                 }
121
122                 /* read the word at location addr in the USER area. */
123                 case PTRACE_PEEKUSR: {
124                         unsigned long tmp;
125                         
126                         ret = -EIO;
127                         if ((addr & 3) || addr < 0 ||
128                             addr > sizeof(struct user) - 3)
129                                 break;
130                         
131                         tmp = 0;  /* Default return condition */
132                         addr = addr >> 2; /* temporary hack. */
133                         ret = -EIO;
134                         if (addr < 19) {
135                                 tmp = get_reg(child, addr);
136                                 if (addr == PT_SR)
137                                         tmp >>= 16;
138                         } else if (addr >= 21 && addr < 49) {
139                                 tmp = child->thread.fp[addr - 21];
140 #ifdef CONFIG_M68KFPU_EMU
141                                 /* Convert internal fpu reg representation
142                                  * into long double format
143                                  */
144                                 if (FPU_IS_EMU && (addr < 45) && !(addr % 3))
145                                         tmp = ((tmp & 0xffff0000) << 15) |
146                                               ((tmp & 0x0000ffff) << 16);
147 #endif
148                         } else if (addr == 49) {
149                                 tmp = child->mm->start_code;
150                         } else if (addr == 50) {
151                                 tmp = child->mm->start_data;
152                         } else if (addr == 51) {
153                                 tmp = child->mm->end_code;
154                         } else
155                                 break;
156                         ret = put_user(tmp,(unsigned long *) data);
157                         break;
158                 }
159
160                 /* when I and D space are separate, this will have to be fixed. */
161                 case PTRACE_POKETEXT: /* write the word at location addr. */
162                 case PTRACE_POKEDATA:
163                         ret = 0;
164                         if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
165                                 break;
166                         ret = -EIO;
167                         break;
168
169                 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
170                         ret = -EIO;
171                         if ((addr & 3) || addr < 0 ||
172                             addr > sizeof(struct user) - 3)
173                                 break;
174
175                         addr = addr >> 2; /* temporary hack. */
176                             
177                         if (addr == PT_SR) {
178                                 data &= SR_MASK;
179                                 data <<= 16;
180                                 data |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
181                         }
182                         if (addr < 19) {
183                                 if (put_reg(child, addr, data))
184                                         break;
185                                 ret = 0;
186                                 break;
187                         }
188                         if (addr >= 21 && addr < 48)
189                         {
190 #ifdef CONFIG_M68KFPU_EMU
191                                 /* Convert long double format
192                                  * into internal fpu reg representation
193                                  */
194                                 if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) {
195                                         data = (unsigned long)data << 15;
196                                         data = (data & 0xffff0000) |
197                                                ((data & 0x0000ffff) >> 1);
198                                 }
199 #endif
200                                 child->thread.fp[addr - 21] = data;
201                                 ret = 0;
202                         }
203                         break;
204
205                 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
206                 case PTRACE_CONT: { /* restart after signal. */
207                         long tmp;
208
209                         ret = -EIO;
210                         if (!valid_signal(data))
211                                 break;
212                         if (request == PTRACE_SYSCALL)
213                                 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
214                         else
215                                 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
216                         child->exit_code = data;
217                         /* make sure the single step bit is not set. */
218                         tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
219                         put_reg(child, PT_SR, tmp);
220                         wake_up_process(child);
221                         ret = 0;
222                         break;
223                 }
224
225                 /*
226                  * make the child exit.  Best I can do is send it a sigkill. 
227                  * perhaps it should be put in the status that it wants to 
228                  * exit.
229                  */
230                 case PTRACE_KILL: {
231                         long tmp;
232
233                         ret = 0;
234                         if (child->exit_state == EXIT_ZOMBIE) /* already dead */
235                                 break;
236                         child->exit_code = SIGKILL;
237                         /* make sure the single step bit is not set. */
238                         tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
239                         put_reg(child, PT_SR, tmp);
240                         wake_up_process(child);
241                         break;
242                 }
243
244                 case PTRACE_SINGLESTEP: {  /* set the trap flag. */
245                         long tmp;
246
247                         ret = -EIO;
248                         if (!valid_signal(data))
249                                 break;
250                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
251                         tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16);
252                         put_reg(child, PT_SR, tmp);
253
254                         child->exit_code = data;
255                         /* give it a chance to run. */
256                         wake_up_process(child);
257                         ret = 0;
258                         break;
259                 }
260
261                 case PTRACE_DETACH:     /* detach a process that was attached. */
262                         ret = ptrace_detach(child, data);
263                         break;
264
265                 case PTRACE_GETREGS: { /* Get all gp regs from the child. */
266                         int i;
267                         unsigned long tmp;
268                         for (i = 0; i < 19; i++) {
269                             tmp = get_reg(child, i);
270                             if (i == PT_SR)
271                                 tmp >>= 16;
272                             if (put_user(tmp, (unsigned long *) data)) {
273                                 ret = -EFAULT;
274                                 break;
275                             }
276                             data += sizeof(long);
277                         }
278                         ret = 0;
279                         break;
280                 }
281
282                 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
283                         int i;
284                         unsigned long tmp;
285                         for (i = 0; i < 19; i++) {
286                             if (get_user(tmp, (unsigned long *) data)) {
287                                 ret = -EFAULT;
288                                 break;
289                             }
290                             if (i == PT_SR) {
291                                 tmp &= SR_MASK;
292                                 tmp <<= 16;
293                                 tmp |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
294                             }
295                             put_reg(child, i, tmp);
296                             data += sizeof(long);
297                         }
298                         ret = 0;
299                         break;
300                 }
301
302 #ifdef PTRACE_GETFPREGS
303                 case PTRACE_GETFPREGS: { /* Get the child FPU state. */
304                         ret = 0;
305                         if (copy_to_user((void *)data, &child->thread.fp,
306                                          sizeof(struct user_m68kfp_struct)))
307                                 ret = -EFAULT;
308                         break;
309                 }
310 #endif
311
312 #ifdef PTRACE_SETFPREGS
313                 case PTRACE_SETFPREGS: { /* Set the child FPU state. */
314                         ret = 0;
315                         if (copy_from_user(&child->thread.fp, (void *)data,
316                                            sizeof(struct user_m68kfp_struct)))
317                                 ret = -EFAULT;
318                         break;
319                 }
320 #endif
321
322                 default:
323                         ret = -EIO;
324                         break;
325         }
326         return ret;
327 }
328
329 asmlinkage void syscall_trace(void)
330 {
331         if (!test_thread_flag(TIF_SYSCALL_TRACE))
332                 return;
333         if (!(current->ptrace & PT_PTRACED))
334                 return;
335         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
336                                  ? 0x80 : 0));
337         /*
338          * this isn't the same as continuing with a signal, but it will do
339          * for normal use.  strace only continues with a signal if the
340          * stopping signal is not SIGTRAP.  -brl
341          */
342         if (current->exit_code) {
343                 send_sig(current->exit_code, current, 1);
344                 current->exit_code = 0;
345         }
346 }