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1da177e4 LT |
1 | /* |
2 | * linux/arch/m68k/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/config.h> | |
7ed20e1a | 22 | #include <linux/signal.h> |
1da177e4 LT |
23 | |
24 | #include <asm/uaccess.h> | |
25 | #include <asm/page.h> | |
26 | #include <asm/pgtable.h> | |
27 | #include <asm/system.h> | |
28 | #include <asm/processor.h> | |
29 | ||
30 | /* | |
31 | * does not yet catch signals sent when the child dies. | |
32 | * in exit.c or in signal.c. | |
33 | */ | |
34 | ||
35 | /* determines which bits in the SR the user has access to. */ | |
36 | /* 1 = access 0 = no access */ | |
37 | #define SR_MASK 0x001f | |
38 | ||
39 | /* sets the trace bits. */ | |
40 | #define TRACE_BITS 0x8000 | |
41 | ||
42 | /* Find the stack offset for a register, relative to thread.esp0. */ | |
43 | #define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg) | |
44 | #define SW_REG(reg) ((long)&((struct switch_stack *)0)->reg \ | |
45 | - sizeof(struct switch_stack)) | |
46 | /* Mapping from PT_xxx to the stack offset at which the register is | |
47 | saved. Notice that usp has no stack-slot and needs to be treated | |
48 | specially (see get_reg/put_reg below). */ | |
49 | static int regoff[] = { | |
50 | [0] = PT_REG(d1), | |
51 | [1] = PT_REG(d2), | |
52 | [2] = PT_REG(d3), | |
53 | [3] = PT_REG(d4), | |
54 | [4] = PT_REG(d5), | |
55 | [5] = SW_REG(d6), | |
56 | [6] = SW_REG(d7), | |
57 | [7] = PT_REG(a0), | |
58 | [8] = PT_REG(a1), | |
59 | [9] = PT_REG(a2), | |
60 | [10] = SW_REG(a3), | |
61 | [11] = SW_REG(a4), | |
62 | [12] = SW_REG(a5), | |
63 | [13] = SW_REG(a6), | |
64 | [14] = PT_REG(d0), | |
65 | [15] = -1, | |
66 | [16] = PT_REG(orig_d0), | |
67 | [17] = PT_REG(sr), | |
68 | [18] = PT_REG(pc), | |
69 | }; | |
70 | ||
71 | /* | |
72 | * Get contents of register REGNO in task TASK. | |
73 | */ | |
74 | static inline long get_reg(struct task_struct *task, int regno) | |
75 | { | |
76 | unsigned long *addr; | |
77 | ||
78 | if (regno == PT_USP) | |
79 | addr = &task->thread.usp; | |
80 | else if (regno < sizeof(regoff)/sizeof(regoff[0])) | |
81 | addr = (unsigned long *)(task->thread.esp0 + regoff[regno]); | |
82 | else | |
83 | return 0; | |
84 | return *addr; | |
85 | } | |
86 | ||
87 | /* | |
88 | * Write contents of register REGNO in task TASK. | |
89 | */ | |
90 | static inline int put_reg(struct task_struct *task, int regno, | |
91 | unsigned long data) | |
92 | { | |
93 | unsigned long *addr; | |
94 | ||
95 | if (regno == PT_USP) | |
96 | addr = &task->thread.usp; | |
97 | else if (regno < sizeof(regoff)/sizeof(regoff[0])) | |
98 | addr = (unsigned long *) (task->thread.esp0 + regoff[regno]); | |
99 | else | |
100 | return -1; | |
101 | *addr = data; | |
102 | return 0; | |
103 | } | |
104 | ||
105 | /* | |
106 | * Called by kernel/ptrace.c when detaching.. | |
107 | * | |
108 | * Make sure the single step bit is not set. | |
109 | */ | |
110 | void ptrace_disable(struct task_struct *child) | |
111 | { | |
112 | unsigned long tmp; | |
113 | /* make sure the single step bit is not set. */ | |
114 | tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16); | |
115 | put_reg(child, PT_SR, tmp); | |
116 | child->thread.work.delayed_trace = 0; | |
117 | child->thread.work.syscall_trace = 0; | |
118 | } | |
119 | ||
120 | asmlinkage int sys_ptrace(long request, long pid, long addr, long data) | |
121 | { | |
122 | struct task_struct *child; | |
123 | int ret; | |
124 | ||
125 | lock_kernel(); | |
126 | ret = -EPERM; | |
127 | if (request == PTRACE_TRACEME) { | |
128 | /* are we already being traced? */ | |
129 | if (current->ptrace & PT_PTRACED) | |
130 | goto out; | |
131 | /* set the ptrace bit in the process flags. */ | |
132 | current->ptrace |= PT_PTRACED; | |
133 | ret = 0; | |
134 | goto out; | |
135 | } | |
136 | ret = -ESRCH; | |
137 | read_lock(&tasklist_lock); | |
138 | child = find_task_by_pid(pid); | |
139 | if (child) | |
140 | get_task_struct(child); | |
141 | read_unlock(&tasklist_lock); | |
142 | if (!child) | |
143 | goto out; | |
144 | ||
145 | ret = -EPERM; | |
146 | if (pid == 1) /* you may not mess with init */ | |
147 | goto out_tsk; | |
148 | ||
149 | if (request == PTRACE_ATTACH) { | |
150 | ret = ptrace_attach(child); | |
151 | goto out_tsk; | |
152 | } | |
153 | ||
154 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
155 | if (ret < 0) | |
156 | goto out_tsk; | |
157 | ||
158 | switch (request) { | |
159 | /* when I and D space are separate, these will need to be fixed. */ | |
160 | case PTRACE_PEEKTEXT: /* read word at location addr. */ | |
161 | case PTRACE_PEEKDATA: { | |
162 | unsigned long tmp; | |
163 | int copied; | |
164 | ||
165 | copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); | |
166 | ret = -EIO; | |
167 | if (copied != sizeof(tmp)) | |
168 | break; | |
169 | ret = put_user(tmp,(unsigned long *) data); | |
170 | break; | |
171 | } | |
172 | ||
173 | /* read the word at location addr in the USER area. */ | |
174 | case PTRACE_PEEKUSR: { | |
175 | unsigned long tmp; | |
176 | ||
177 | ret = -EIO; | |
178 | if ((addr & 3) || addr < 0 || | |
179 | addr > sizeof(struct user) - 3) | |
180 | break; | |
181 | ||
182 | tmp = 0; /* Default return condition */ | |
183 | addr = addr >> 2; /* temporary hack. */ | |
184 | ret = -EIO; | |
185 | if (addr < 19) { | |
186 | tmp = get_reg(child, addr); | |
187 | if (addr == PT_SR) | |
188 | tmp >>= 16; | |
189 | } else if (addr >= 21 && addr < 49) { | |
190 | tmp = child->thread.fp[addr - 21]; | |
191 | #ifdef CONFIG_M68KFPU_EMU | |
192 | /* Convert internal fpu reg representation | |
193 | * into long double format | |
194 | */ | |
195 | if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) | |
196 | tmp = ((tmp & 0xffff0000) << 15) | | |
197 | ((tmp & 0x0000ffff) << 16); | |
198 | #endif | |
199 | } else | |
200 | break; | |
201 | ret = put_user(tmp,(unsigned long *) data); | |
202 | break; | |
203 | } | |
204 | ||
205 | /* when I and D space are separate, this will have to be fixed. */ | |
206 | case PTRACE_POKETEXT: /* write the word at location addr. */ | |
207 | case PTRACE_POKEDATA: | |
208 | ret = 0; | |
209 | if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data)) | |
210 | break; | |
211 | ret = -EIO; | |
212 | break; | |
213 | ||
214 | case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ | |
215 | ret = -EIO; | |
216 | if ((addr & 3) || addr < 0 || | |
217 | addr > sizeof(struct user) - 3) | |
218 | break; | |
219 | ||
220 | addr = addr >> 2; /* temporary hack. */ | |
221 | ||
222 | if (addr == PT_SR) { | |
223 | data &= SR_MASK; | |
224 | data <<= 16; | |
225 | data |= get_reg(child, PT_SR) & ~(SR_MASK << 16); | |
226 | } | |
227 | if (addr < 19) { | |
228 | if (put_reg(child, addr, data)) | |
229 | break; | |
230 | ret = 0; | |
231 | break; | |
232 | } | |
233 | if (addr >= 21 && addr < 48) | |
234 | { | |
235 | #ifdef CONFIG_M68KFPU_EMU | |
236 | /* Convert long double format | |
237 | * into internal fpu reg representation | |
238 | */ | |
239 | if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) { | |
240 | data = (unsigned long)data << 15; | |
241 | data = (data & 0xffff0000) | | |
242 | ((data & 0x0000ffff) >> 1); | |
243 | } | |
244 | #endif | |
245 | child->thread.fp[addr - 21] = data; | |
246 | ret = 0; | |
247 | } | |
248 | break; | |
249 | ||
250 | case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ | |
251 | case PTRACE_CONT: { /* restart after signal. */ | |
252 | long tmp; | |
253 | ||
254 | ret = -EIO; | |
7ed20e1a | 255 | if (!valid_signal(data)) |
1da177e4 LT |
256 | break; |
257 | if (request == PTRACE_SYSCALL) { | |
258 | child->thread.work.syscall_trace = ~0; | |
259 | } else { | |
260 | child->thread.work.syscall_trace = 0; | |
261 | } | |
262 | child->exit_code = data; | |
263 | /* make sure the single step bit is not set. */ | |
264 | tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16); | |
265 | put_reg(child, PT_SR, tmp); | |
266 | child->thread.work.delayed_trace = 0; | |
267 | wake_up_process(child); | |
268 | ret = 0; | |
269 | break; | |
270 | } | |
271 | ||
272 | /* | |
273 | * make the child exit. Best I can do is send it a sigkill. | |
274 | * perhaps it should be put in the status that it wants to | |
275 | * exit. | |
276 | */ | |
277 | case PTRACE_KILL: { | |
278 | long tmp; | |
279 | ||
280 | ret = 0; | |
281 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ | |
282 | break; | |
283 | child->exit_code = SIGKILL; | |
284 | /* make sure the single step bit is not set. */ | |
285 | tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16); | |
286 | put_reg(child, PT_SR, tmp); | |
287 | child->thread.work.delayed_trace = 0; | |
288 | wake_up_process(child); | |
289 | break; | |
290 | } | |
291 | ||
292 | case PTRACE_SINGLESTEP: { /* set the trap flag. */ | |
293 | long tmp; | |
294 | ||
295 | ret = -EIO; | |
7ed20e1a | 296 | if (!valid_signal(data)) |
1da177e4 LT |
297 | break; |
298 | child->thread.work.syscall_trace = 0; | |
299 | tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16); | |
300 | put_reg(child, PT_SR, tmp); | |
301 | child->thread.work.delayed_trace = 1; | |
302 | ||
303 | child->exit_code = data; | |
304 | /* give it a chance to run. */ | |
305 | wake_up_process(child); | |
306 | ret = 0; | |
307 | break; | |
308 | } | |
309 | ||
310 | case PTRACE_DETACH: /* detach a process that was attached. */ | |
311 | ret = ptrace_detach(child, data); | |
312 | break; | |
313 | ||
314 | case PTRACE_GETREGS: { /* Get all gp regs from the child. */ | |
315 | int i; | |
316 | unsigned long tmp; | |
317 | for (i = 0; i < 19; i++) { | |
318 | tmp = get_reg(child, i); | |
319 | if (i == PT_SR) | |
320 | tmp >>= 16; | |
321 | if (put_user(tmp, (unsigned long *) data)) { | |
322 | ret = -EFAULT; | |
323 | break; | |
324 | } | |
325 | data += sizeof(long); | |
326 | } | |
327 | ret = 0; | |
328 | break; | |
329 | } | |
330 | ||
331 | case PTRACE_SETREGS: { /* Set all gp regs in the child. */ | |
332 | int i; | |
333 | unsigned long tmp; | |
334 | for (i = 0; i < 19; i++) { | |
335 | if (get_user(tmp, (unsigned long *) data)) { | |
336 | ret = -EFAULT; | |
337 | break; | |
338 | } | |
339 | if (i == PT_SR) { | |
340 | tmp &= SR_MASK; | |
341 | tmp <<= 16; | |
342 | tmp |= get_reg(child, PT_SR) & ~(SR_MASK << 16); | |
343 | } | |
344 | put_reg(child, i, tmp); | |
345 | data += sizeof(long); | |
346 | } | |
347 | ret = 0; | |
348 | break; | |
349 | } | |
350 | ||
351 | case PTRACE_GETFPREGS: { /* Get the child FPU state. */ | |
352 | ret = 0; | |
353 | if (copy_to_user((void *)data, &child->thread.fp, | |
354 | sizeof(struct user_m68kfp_struct))) | |
355 | ret = -EFAULT; | |
356 | break; | |
357 | } | |
358 | ||
359 | case PTRACE_SETFPREGS: { /* Set the child FPU state. */ | |
360 | ret = 0; | |
361 | if (copy_from_user(&child->thread.fp, (void *)data, | |
362 | sizeof(struct user_m68kfp_struct))) | |
363 | ret = -EFAULT; | |
364 | break; | |
365 | } | |
366 | ||
367 | default: | |
368 | ret = ptrace_request(child, request, addr, data); | |
369 | break; | |
370 | } | |
371 | out_tsk: | |
372 | put_task_struct(child); | |
373 | out: | |
374 | unlock_kernel(); | |
375 | return ret; | |
376 | } | |
377 | ||
378 | asmlinkage void syscall_trace(void) | |
379 | { | |
380 | if (!current->thread.work.delayed_trace && | |
381 | !current->thread.work.syscall_trace) | |
382 | return; | |
383 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) | |
384 | ? 0x80 : 0)); | |
385 | /* | |
386 | * this isn't the same as continuing with a signal, but it will do | |
387 | * for normal use. strace only continues with a signal if the | |
388 | * stopping signal is not SIGTRAP. -brl | |
389 | */ | |
390 | if (current->exit_code) { | |
391 | send_sig(current->exit_code, current, 1); | |
392 | current->exit_code = 0; | |
393 | } | |
394 | } |