ptrace: use ptrace_request() in the remaining architectures
[linux-3.10.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/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 void user_enable_single_step(struct task_struct *task)
90 {
91         unsigned long srflags;
92         srflags = get_reg(task, PT_SR) | (TRACE_BITS << 16);
93         put_reg(task, PT_SR, srflags);
94 }
95
96 void user_disable_single_step(struct task_struct *task)
97 {
98         unsigned long srflags;
99         srflags = get_reg(task, PT_SR) & ~(TRACE_BITS << 16);
100         put_reg(task, PT_SR, srflags);
101 }
102
103 /*
104  * Called by kernel/ptrace.c when detaching..
105  *
106  * Make sure the single step bit is not set.
107  */
108 void ptrace_disable(struct task_struct *child)
109 {
110         /* make sure the single step bit is not set. */
111         user_disable_single_step(child);
112 }
113
114 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
115 {
116         int ret;
117
118         switch (request) {
119                 /* read the word at location addr in the USER area. */
120                 case PTRACE_PEEKUSR: {
121                         unsigned long tmp;
122                         
123                         ret = -EIO;
124                         if ((addr & 3) || addr < 0 ||
125                             addr > sizeof(struct user) - 3)
126                                 break;
127                         
128                         tmp = 0;  /* Default return condition */
129                         addr = addr >> 2; /* temporary hack. */
130                         ret = -EIO;
131                         if (addr < 19) {
132                                 tmp = get_reg(child, addr);
133                                 if (addr == PT_SR)
134                                         tmp >>= 16;
135                         } else if (addr >= 21 && addr < 49) {
136                                 tmp = child->thread.fp[addr - 21];
137 #ifdef CONFIG_M68KFPU_EMU
138                                 /* Convert internal fpu reg representation
139                                  * into long double format
140                                  */
141                                 if (FPU_IS_EMU && (addr < 45) && !(addr % 3))
142                                         tmp = ((tmp & 0xffff0000) << 15) |
143                                               ((tmp & 0x0000ffff) << 16);
144 #endif
145                         } else if (addr == 49) {
146                                 tmp = child->mm->start_code;
147                         } else if (addr == 50) {
148                                 tmp = child->mm->start_data;
149                         } else if (addr == 51) {
150                                 tmp = child->mm->end_code;
151                         } else
152                                 break;
153                         ret = put_user(tmp,(unsigned long *) data);
154                         break;
155                 }
156
157                 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
158                         ret = -EIO;
159                         if ((addr & 3) || addr < 0 ||
160                             addr > sizeof(struct user) - 3)
161                                 break;
162
163                         addr = addr >> 2; /* temporary hack. */
164                             
165                         if (addr == PT_SR) {
166                                 data &= SR_MASK;
167                                 data <<= 16;
168                                 data |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
169                         }
170                         if (addr < 19) {
171                                 if (put_reg(child, addr, data))
172                                         break;
173                                 ret = 0;
174                                 break;
175                         }
176                         if (addr >= 21 && addr < 48)
177                         {
178 #ifdef CONFIG_M68KFPU_EMU
179                                 /* Convert long double format
180                                  * into internal fpu reg representation
181                                  */
182                                 if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) {
183                                         data = (unsigned long)data << 15;
184                                         data = (data & 0xffff0000) |
185                                                ((data & 0x0000ffff) >> 1);
186                                 }
187 #endif
188                                 child->thread.fp[addr - 21] = data;
189                                 ret = 0;
190                         }
191                         break;
192
193                 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
194                 case PTRACE_CONT: { /* restart after signal. */
195                         long tmp;
196
197                         ret = -EIO;
198                         if (!valid_signal(data))
199                                 break;
200                         if (request == PTRACE_SYSCALL)
201                                 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
202                         else
203                                 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
204                         child->exit_code = data;
205                         /* make sure the single step bit is not set. */
206                         tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
207                         put_reg(child, PT_SR, tmp);
208                         wake_up_process(child);
209                         ret = 0;
210                         break;
211                 }
212
213                 /*
214                  * make the child exit.  Best I can do is send it a sigkill. 
215                  * perhaps it should be put in the status that it wants to 
216                  * exit.
217                  */
218                 case PTRACE_KILL: {
219                         long tmp;
220
221                         ret = 0;
222                         if (child->exit_state == EXIT_ZOMBIE) /* already dead */
223                                 break;
224                         child->exit_code = SIGKILL;
225                         /* make sure the single step bit is not set. */
226                         tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
227                         put_reg(child, PT_SR, tmp);
228                         wake_up_process(child);
229                         break;
230                 }
231
232                 case PTRACE_SINGLESTEP: {  /* set the trap flag. */
233                         long tmp;
234
235                         ret = -EIO;
236                         if (!valid_signal(data))
237                                 break;
238                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
239                         tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16);
240                         put_reg(child, PT_SR, tmp);
241
242                         child->exit_code = data;
243                         /* give it a chance to run. */
244                         wake_up_process(child);
245                         ret = 0;
246                         break;
247                 }
248
249                 case PTRACE_GETREGS: { /* Get all gp regs from the child. */
250                         int i;
251                         unsigned long tmp;
252                         for (i = 0; i < 19; i++) {
253                             tmp = get_reg(child, i);
254                             if (i == PT_SR)
255                                 tmp >>= 16;
256                             if (put_user(tmp, (unsigned long *) data)) {
257                                 ret = -EFAULT;
258                                 break;
259                             }
260                             data += sizeof(long);
261                         }
262                         ret = 0;
263                         break;
264                 }
265
266                 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
267                         int i;
268                         unsigned long tmp;
269                         for (i = 0; i < 19; i++) {
270                             if (get_user(tmp, (unsigned long *) data)) {
271                                 ret = -EFAULT;
272                                 break;
273                             }
274                             if (i == PT_SR) {
275                                 tmp &= SR_MASK;
276                                 tmp <<= 16;
277                                 tmp |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
278                             }
279                             put_reg(child, i, tmp);
280                             data += sizeof(long);
281                         }
282                         ret = 0;
283                         break;
284                 }
285
286 #ifdef PTRACE_GETFPREGS
287                 case PTRACE_GETFPREGS: { /* Get the child FPU state. */
288                         ret = 0;
289                         if (copy_to_user((void *)data, &child->thread.fp,
290                                          sizeof(struct user_m68kfp_struct)))
291                                 ret = -EFAULT;
292                         break;
293                 }
294 #endif
295
296 #ifdef PTRACE_SETFPREGS
297                 case PTRACE_SETFPREGS: { /* Set the child FPU state. */
298                         ret = 0;
299                         if (copy_from_user(&child->thread.fp, (void *)data,
300                                            sizeof(struct user_m68kfp_struct)))
301                                 ret = -EFAULT;
302                         break;
303                 }
304 #endif
305
306         case PTRACE_GET_THREAD_AREA:
307                 ret = put_user(task_thread_info(child)->tp_value,
308                                (unsigned long __user *)data);
309                 break;
310
311                 default:
312                         ret = ptrace_request(child, request, addr, data);
313                         break;
314         }
315         return ret;
316 }
317
318 asmlinkage void syscall_trace(void)
319 {
320         if (!test_thread_flag(TIF_SYSCALL_TRACE))
321                 return;
322         if (!(current->ptrace & PT_PTRACED))
323                 return;
324         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
325                                  ? 0x80 : 0));
326         /*
327          * this isn't the same as continuing with a signal, but it will do
328          * for normal use.  strace only continues with a signal if the
329          * stopping signal is not SIGTRAP.  -brl
330          */
331         if (current->exit_code) {
332                 send_sig(current->exit_code, current, 1);
333                 current->exit_code = 0;
334         }
335 }