Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-2.6] / 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/errno.h>
18 #include <linux/ptrace.h>
19 #include <linux/user.h>
20 #include <linux/signal.h>
21
22 #include <asm/uaccess.h>
23 #include <asm/page.h>
24 #include <asm/pgtable.h>
25 #include <asm/system.h>
26 #include <asm/processor.h>
27
28 /*
29  * does not yet catch signals sent when the child dies.
30  * in exit.c or in signal.c.
31  */
32
33 /* determines which bits in the SR the user has access to. */
34 /* 1 = access 0 = no access */
35 #define SR_MASK 0x001f
36
37 /* sets the trace bits. */
38 #define TRACE_BITS 0x8000
39
40 /* Find the stack offset for a register, relative to thread.esp0. */
41 #define PT_REG(reg)     ((long)&((struct pt_regs *)0)->reg)
42 #define SW_REG(reg)     ((long)&((struct switch_stack *)0)->reg \
43                          - sizeof(struct switch_stack))
44 /* Mapping from PT_xxx to the stack offset at which the register is
45    saved.  Notice that usp has no stack-slot and needs to be treated
46    specially (see get_reg/put_reg below). */
47 static int regoff[] = {
48         PT_REG(d1), PT_REG(d2), PT_REG(d3), PT_REG(d4),
49         PT_REG(d5), SW_REG(d6), SW_REG(d7), PT_REG(a0),
50         PT_REG(a1), PT_REG(a2), SW_REG(a3), SW_REG(a4),
51         SW_REG(a5), SW_REG(a6), PT_REG(d0), -1,
52         PT_REG(orig_d0), PT_REG(sr), PT_REG(pc),
53 };
54
55 /*
56  * Get contents of register REGNO in task TASK.
57  */
58 static inline long get_reg(struct task_struct *task, int regno)
59 {
60         unsigned long *addr;
61
62         if (regno == PT_USP)
63                 addr = &task->thread.usp;
64         else if (regno < ARRAY_SIZE(regoff))
65                 addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
66         else
67                 return 0;
68         return *addr;
69 }
70
71 /*
72  * Write contents of register REGNO in task TASK.
73  */
74 static inline int put_reg(struct task_struct *task, int regno,
75                           unsigned long data)
76 {
77         unsigned long *addr;
78
79         if (regno == PT_USP)
80                 addr = &task->thread.usp;
81         else if (regno < ARRAY_SIZE(regoff))
82                 addr = (unsigned long *) (task->thread.esp0 + regoff[regno]);
83         else
84                 return -1;
85         *addr = data;
86         return 0;
87 }
88
89 /*
90  * Called by kernel/ptrace.c when detaching..
91  *
92  * Make sure the single step bit is not set.
93  */
94 void ptrace_disable(struct task_struct *child)
95 {
96         unsigned long tmp;
97         /* make sure the single step bit is not set. */
98         tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
99         put_reg(child, PT_SR, tmp);
100 }
101
102 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
103 {
104         int ret;
105
106         switch (request) {
107                 /* when I and D space are separate, these will need to be fixed. */
108                 case PTRACE_PEEKTEXT: /* read word at location addr. */ 
109                 case PTRACE_PEEKDATA: {
110                         unsigned long tmp;
111                         int copied;
112
113                         copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
114                         ret = -EIO;
115                         if (copied != sizeof(tmp))
116                                 break;
117                         ret = put_user(tmp,(unsigned long *) data);
118                         break;
119                 }
120
121                 /* read the word at location addr in the USER area. */
122                 case PTRACE_PEEKUSR: {
123                         unsigned long tmp;
124                         
125                         ret = -EIO;
126                         if ((addr & 3) || addr < 0 ||
127                             addr > sizeof(struct user) - 3)
128                                 break;
129                         
130                         tmp = 0;  /* Default return condition */
131                         addr = addr >> 2; /* temporary hack. */
132                         ret = -EIO;
133                         if (addr < 19) {
134                                 tmp = get_reg(child, addr);
135                                 if (addr == PT_SR)
136                                         tmp >>= 16;
137                         } else if (addr >= 21 && addr < 49) {
138                                 tmp = child->thread.fp[addr - 21];
139 #ifdef CONFIG_M68KFPU_EMU
140                                 /* Convert internal fpu reg representation
141                                  * into long double format
142                                  */
143                                 if (FPU_IS_EMU && (addr < 45) && !(addr % 3))
144                                         tmp = ((tmp & 0xffff0000) << 15) |
145                                               ((tmp & 0x0000ffff) << 16);
146 #endif
147                         } else if (addr == 49) {
148                                 tmp = child->mm->start_code;
149                         } else if (addr == 50) {
150                                 tmp = child->mm->start_data;
151                         } else if (addr == 51) {
152                                 tmp = child->mm->end_code;
153                         } else
154                                 break;
155                         ret = put_user(tmp,(unsigned long *) data);
156                         break;
157                 }
158
159                 /* when I and D space are separate, this will have to be fixed. */
160                 case PTRACE_POKETEXT: /* write the word at location addr. */
161                 case PTRACE_POKEDATA:
162                         ret = 0;
163                         if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
164                                 break;
165                         ret = -EIO;
166                         break;
167
168                 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
169                         ret = -EIO;
170                         if ((addr & 3) || addr < 0 ||
171                             addr > sizeof(struct user) - 3)
172                                 break;
173
174                         addr = addr >> 2; /* temporary hack. */
175                             
176                         if (addr == PT_SR) {
177                                 data &= SR_MASK;
178                                 data <<= 16;
179                                 data |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
180                         }
181                         if (addr < 19) {
182                                 if (put_reg(child, addr, data))
183                                         break;
184                                 ret = 0;
185                                 break;
186                         }
187                         if (addr >= 21 && addr < 48)
188                         {
189 #ifdef CONFIG_M68KFPU_EMU
190                                 /* Convert long double format
191                                  * into internal fpu reg representation
192                                  */
193                                 if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) {
194                                         data = (unsigned long)data << 15;
195                                         data = (data & 0xffff0000) |
196                                                ((data & 0x0000ffff) >> 1);
197                                 }
198 #endif
199                                 child->thread.fp[addr - 21] = data;
200                                 ret = 0;
201                         }
202                         break;
203
204                 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
205                 case PTRACE_CONT: { /* restart after signal. */
206                         long tmp;
207
208                         ret = -EIO;
209                         if (!valid_signal(data))
210                                 break;
211                         if (request == PTRACE_SYSCALL)
212                                 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
213                         else
214                                 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
215                         child->exit_code = data;
216                         /* make sure the single step bit is not set. */
217                         tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
218                         put_reg(child, PT_SR, tmp);
219                         wake_up_process(child);
220                         ret = 0;
221                         break;
222                 }
223
224                 /*
225                  * make the child exit.  Best I can do is send it a sigkill. 
226                  * perhaps it should be put in the status that it wants to 
227                  * exit.
228                  */
229                 case PTRACE_KILL: {
230                         long tmp;
231
232                         ret = 0;
233                         if (child->exit_state == EXIT_ZOMBIE) /* already dead */
234                                 break;
235                         child->exit_code = SIGKILL;
236                         /* make sure the single step bit is not set. */
237                         tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
238                         put_reg(child, PT_SR, tmp);
239                         wake_up_process(child);
240                         break;
241                 }
242
243                 case PTRACE_SINGLESTEP: {  /* set the trap flag. */
244                         long tmp;
245
246                         ret = -EIO;
247                         if (!valid_signal(data))
248                                 break;
249                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
250                         tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16);
251                         put_reg(child, PT_SR, tmp);
252
253                         child->exit_code = data;
254                         /* give it a chance to run. */
255                         wake_up_process(child);
256                         ret = 0;
257                         break;
258                 }
259
260                 case PTRACE_DETACH:     /* detach a process that was attached. */
261                         ret = ptrace_detach(child, data);
262                         break;
263
264                 case PTRACE_GETREGS: { /* Get all gp regs from the child. */
265                         int i;
266                         unsigned long tmp;
267                         for (i = 0; i < 19; i++) {
268                             tmp = get_reg(child, i);
269                             if (i == PT_SR)
270                                 tmp >>= 16;
271                             if (put_user(tmp, (unsigned long *) data)) {
272                                 ret = -EFAULT;
273                                 break;
274                             }
275                             data += sizeof(long);
276                         }
277                         ret = 0;
278                         break;
279                 }
280
281                 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
282                         int i;
283                         unsigned long tmp;
284                         for (i = 0; i < 19; i++) {
285                             if (get_user(tmp, (unsigned long *) data)) {
286                                 ret = -EFAULT;
287                                 break;
288                             }
289                             if (i == PT_SR) {
290                                 tmp &= SR_MASK;
291                                 tmp <<= 16;
292                                 tmp |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
293                             }
294                             put_reg(child, i, tmp);
295                             data += sizeof(long);
296                         }
297                         ret = 0;
298                         break;
299                 }
300
301 #ifdef PTRACE_GETFPREGS
302                 case PTRACE_GETFPREGS: { /* Get the child FPU state. */
303                         ret = 0;
304                         if (copy_to_user((void *)data, &child->thread.fp,
305                                          sizeof(struct user_m68kfp_struct)))
306                                 ret = -EFAULT;
307                         break;
308                 }
309 #endif
310
311 #ifdef PTRACE_SETFPREGS
312                 case PTRACE_SETFPREGS: { /* Set the child FPU state. */
313                         ret = 0;
314                         if (copy_from_user(&child->thread.fp, (void *)data,
315                                            sizeof(struct user_m68kfp_struct)))
316                                 ret = -EFAULT;
317                         break;
318                 }
319 #endif
320
321                 default:
322                         ret = -EIO;
323                         break;
324         }
325         return ret;
326 }
327
328 asmlinkage void syscall_trace(void)
329 {
330         if (!test_thread_flag(TIF_SYSCALL_TRACE))
331                 return;
332         if (!(current->ptrace & PT_PTRACED))
333                 return;
334         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
335                                  ? 0x80 : 0));
336         /*
337          * this isn't the same as continuing with a signal, but it will do
338          * for normal use.  strace only continues with a signal if the
339          * stopping signal is not SIGTRAP.  -brl
340          */
341         if (current->exit_code) {
342                 send_sig(current->exit_code, current, 1);
343                 current->exit_code = 0;
344         }
345 }