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1da177e4 LT |
1 | /* |
2 | * arch/ppc/kernel/ptrace.c | |
3 | * | |
4 | * PowerPC version | |
5 | * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) | |
6 | * | |
7 | * Derived from "arch/m68k/kernel/ptrace.c" | |
8 | * Copyright (C) 1994 by Hamish Macdonald | |
9 | * Taken from linux/kernel/ptrace.c and modified for M680x0. | |
10 | * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds | |
11 | * | |
12 | * Modified by Cort Dougan (cort@hq.fsmlabs.com) | |
13 | * and Paul Mackerras (paulus@linuxcare.com.au). | |
14 | * | |
15 | * This file is subject to the terms and conditions of the GNU General | |
16 | * Public License. See the file README.legal in the main directory of | |
17 | * this archive for more details. | |
18 | */ | |
19 | ||
20 | #include <linux/kernel.h> | |
21 | #include <linux/sched.h> | |
22 | #include <linux/mm.h> | |
23 | #include <linux/smp.h> | |
24 | #include <linux/smp_lock.h> | |
25 | #include <linux/errno.h> | |
26 | #include <linux/ptrace.h> | |
27 | #include <linux/user.h> | |
28 | #include <linux/security.h> | |
29 | ||
30 | #include <asm/uaccess.h> | |
31 | #include <asm/page.h> | |
32 | #include <asm/pgtable.h> | |
33 | #include <asm/system.h> | |
34 | ||
35 | /* | |
36 | * Set of msr bits that gdb can change on behalf of a process. | |
37 | */ | |
38 | #if defined(CONFIG_40x) || defined(CONFIG_BOOKE) | |
39 | #define MSR_DEBUGCHANGE 0 | |
40 | #else | |
41 | #define MSR_DEBUGCHANGE (MSR_SE | MSR_BE) | |
42 | #endif | |
43 | ||
44 | /* | |
45 | * does not yet catch signals sent when the child dies. | |
46 | * in exit.c or in signal.c. | |
47 | */ | |
48 | ||
49 | /* | |
50 | * Get contents of register REGNO in task TASK. | |
51 | */ | |
52 | static inline unsigned long get_reg(struct task_struct *task, int regno) | |
53 | { | |
54 | if (regno < sizeof(struct pt_regs) / sizeof(unsigned long) | |
55 | && task->thread.regs != NULL) | |
56 | return ((unsigned long *)task->thread.regs)[regno]; | |
57 | return (0); | |
58 | } | |
59 | ||
60 | /* | |
61 | * Write contents of register REGNO in task TASK. | |
62 | */ | |
63 | static inline int put_reg(struct task_struct *task, int regno, | |
64 | unsigned long data) | |
65 | { | |
66 | if (regno <= PT_MQ && task->thread.regs != NULL) { | |
67 | if (regno == PT_MSR) | |
68 | data = (data & MSR_DEBUGCHANGE) | |
69 | | (task->thread.regs->msr & ~MSR_DEBUGCHANGE); | |
70 | ((unsigned long *)task->thread.regs)[regno] = data; | |
71 | return 0; | |
72 | } | |
73 | return -EIO; | |
74 | } | |
75 | ||
76 | #ifdef CONFIG_ALTIVEC | |
77 | /* | |
78 | * Get contents of AltiVec register state in task TASK | |
79 | */ | |
80 | static inline int get_vrregs(unsigned long __user *data, struct task_struct *task) | |
81 | { | |
82 | int i, j; | |
83 | ||
84 | if (!access_ok(VERIFY_WRITE, data, 133 * sizeof(unsigned long))) | |
85 | return -EFAULT; | |
86 | ||
87 | /* copy AltiVec registers VR[0] .. VR[31] */ | |
88 | for (i = 0; i < 32; i++) | |
89 | for (j = 0; j < 4; j++, data++) | |
90 | if (__put_user(task->thread.vr[i].u[j], data)) | |
91 | return -EFAULT; | |
92 | ||
93 | /* copy VSCR */ | |
94 | for (i = 0; i < 4; i++, data++) | |
95 | if (__put_user(task->thread.vscr.u[i], data)) | |
96 | return -EFAULT; | |
97 | ||
98 | /* copy VRSAVE */ | |
99 | if (__put_user(task->thread.vrsave, data)) | |
100 | return -EFAULT; | |
101 | ||
102 | return 0; | |
103 | } | |
104 | ||
105 | /* | |
106 | * Write contents of AltiVec register state into task TASK. | |
107 | */ | |
108 | static inline int set_vrregs(struct task_struct *task, unsigned long __user *data) | |
109 | { | |
110 | int i, j; | |
111 | ||
112 | if (!access_ok(VERIFY_READ, data, 133 * sizeof(unsigned long))) | |
113 | return -EFAULT; | |
114 | ||
115 | /* copy AltiVec registers VR[0] .. VR[31] */ | |
116 | for (i = 0; i < 32; i++) | |
117 | for (j = 0; j < 4; j++, data++) | |
118 | if (__get_user(task->thread.vr[i].u[j], data)) | |
119 | return -EFAULT; | |
120 | ||
121 | /* copy VSCR */ | |
122 | for (i = 0; i < 4; i++, data++) | |
123 | if (__get_user(task->thread.vscr.u[i], data)) | |
124 | return -EFAULT; | |
125 | ||
126 | /* copy VRSAVE */ | |
127 | if (__get_user(task->thread.vrsave, data)) | |
128 | return -EFAULT; | |
129 | ||
130 | return 0; | |
131 | } | |
132 | #endif | |
133 | ||
134 | #ifdef CONFIG_SPE | |
135 | ||
136 | /* | |
137 | * For get_evrregs/set_evrregs functions 'data' has the following layout: | |
138 | * | |
139 | * struct { | |
140 | * u32 evr[32]; | |
141 | * u64 acc; | |
142 | * u32 spefscr; | |
143 | * } | |
144 | */ | |
145 | ||
146 | /* | |
147 | * Get contents of SPE register state in task TASK. | |
148 | */ | |
149 | static inline int get_evrregs(unsigned long *data, struct task_struct *task) | |
150 | { | |
151 | int i; | |
152 | ||
153 | if (!access_ok(VERIFY_WRITE, data, 35 * sizeof(unsigned long))) | |
154 | return -EFAULT; | |
155 | ||
156 | /* copy SPEFSCR */ | |
157 | if (__put_user(task->thread.spefscr, &data[34])) | |
158 | return -EFAULT; | |
159 | ||
160 | /* copy SPE registers EVR[0] .. EVR[31] */ | |
161 | for (i = 0; i < 32; i++, data++) | |
162 | if (__put_user(task->thread.evr[i], data)) | |
163 | return -EFAULT; | |
164 | ||
165 | /* copy ACC */ | |
166 | if (__put_user64(task->thread.acc, (unsigned long long *)data)) | |
167 | return -EFAULT; | |
168 | ||
169 | return 0; | |
170 | } | |
171 | ||
172 | /* | |
173 | * Write contents of SPE register state into task TASK. | |
174 | */ | |
175 | static inline int set_evrregs(struct task_struct *task, unsigned long *data) | |
176 | { | |
177 | int i; | |
178 | ||
179 | if (!access_ok(VERIFY_READ, data, 35 * sizeof(unsigned long))) | |
180 | return -EFAULT; | |
181 | ||
182 | /* copy SPEFSCR */ | |
183 | if (__get_user(task->thread.spefscr, &data[34])) | |
184 | return -EFAULT; | |
185 | ||
186 | /* copy SPE registers EVR[0] .. EVR[31] */ | |
187 | for (i = 0; i < 32; i++, data++) | |
188 | if (__get_user(task->thread.evr[i], data)) | |
189 | return -EFAULT; | |
190 | /* copy ACC */ | |
191 | if (__get_user64(task->thread.acc, (unsigned long long*)data)) | |
192 | return -EFAULT; | |
193 | ||
194 | return 0; | |
195 | } | |
196 | #endif /* CONFIG_SPE */ | |
197 | ||
198 | static inline void | |
199 | set_single_step(struct task_struct *task) | |
200 | { | |
201 | struct pt_regs *regs = task->thread.regs; | |
202 | ||
203 | if (regs != NULL) { | |
204 | #if defined(CONFIG_40x) || defined(CONFIG_BOOKE) | |
205 | task->thread.dbcr0 = DBCR0_IDM | DBCR0_IC; | |
206 | regs->msr |= MSR_DE; | |
207 | #else | |
208 | regs->msr |= MSR_SE; | |
209 | #endif | |
210 | } | |
211 | } | |
212 | ||
213 | static inline void | |
214 | clear_single_step(struct task_struct *task) | |
215 | { | |
216 | struct pt_regs *regs = task->thread.regs; | |
217 | ||
218 | if (regs != NULL) { | |
219 | #if defined(CONFIG_40x) || defined(CONFIG_BOOKE) | |
220 | task->thread.dbcr0 = 0; | |
221 | regs->msr &= ~MSR_DE; | |
222 | #else | |
223 | regs->msr &= ~MSR_SE; | |
224 | #endif | |
225 | } | |
226 | } | |
227 | ||
228 | /* | |
229 | * Called by kernel/ptrace.c when detaching.. | |
230 | * | |
231 | * Make sure single step bits etc are not set. | |
232 | */ | |
233 | void ptrace_disable(struct task_struct *child) | |
234 | { | |
235 | /* make sure the single step bit is not set. */ | |
236 | clear_single_step(child); | |
237 | } | |
238 | ||
239 | int sys_ptrace(long request, long pid, long addr, long data) | |
240 | { | |
241 | struct task_struct *child; | |
242 | int ret = -EPERM; | |
243 | ||
244 | lock_kernel(); | |
245 | if (request == PTRACE_TRACEME) { | |
246 | /* are we already being traced? */ | |
247 | if (current->ptrace & PT_PTRACED) | |
248 | goto out; | |
249 | ret = security_ptrace(current->parent, current); | |
250 | if (ret) | |
251 | goto out; | |
252 | /* set the ptrace bit in the process flags. */ | |
253 | current->ptrace |= PT_PTRACED; | |
254 | ret = 0; | |
255 | goto out; | |
256 | } | |
257 | ret = -ESRCH; | |
258 | read_lock(&tasklist_lock); | |
259 | child = find_task_by_pid(pid); | |
260 | if (child) | |
261 | get_task_struct(child); | |
262 | read_unlock(&tasklist_lock); | |
263 | if (!child) | |
264 | goto out; | |
265 | ||
266 | ret = -EPERM; | |
267 | if (pid == 1) /* you may not mess with init */ | |
268 | goto out_tsk; | |
269 | ||
270 | if (request == PTRACE_ATTACH) { | |
271 | ret = ptrace_attach(child); | |
272 | goto out_tsk; | |
273 | } | |
274 | ||
275 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
276 | if (ret < 0) | |
277 | goto out_tsk; | |
278 | ||
279 | switch (request) { | |
280 | /* when I and D space are separate, these will need to be fixed. */ | |
281 | case PTRACE_PEEKTEXT: /* read word at location addr. */ | |
282 | case PTRACE_PEEKDATA: { | |
283 | unsigned long tmp; | |
284 | int copied; | |
285 | ||
286 | copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); | |
287 | ret = -EIO; | |
288 | if (copied != sizeof(tmp)) | |
289 | break; | |
290 | ret = put_user(tmp,(unsigned long __user *) data); | |
291 | break; | |
292 | } | |
293 | ||
294 | /* read the word at location addr in the USER area. */ | |
295 | /* XXX this will need fixing for 64-bit */ | |
296 | case PTRACE_PEEKUSR: { | |
297 | unsigned long index, tmp; | |
298 | ||
299 | ret = -EIO; | |
300 | /* convert to index and check */ | |
301 | index = (unsigned long) addr >> 2; | |
302 | if ((addr & 3) || index > PT_FPSCR | |
303 | || child->thread.regs == NULL) | |
304 | break; | |
305 | ||
306 | CHECK_FULL_REGS(child->thread.regs); | |
307 | if (index < PT_FPR0) { | |
308 | tmp = get_reg(child, (int) index); | |
309 | } else { | |
310 | preempt_disable(); | |
311 | if (child->thread.regs->msr & MSR_FP) | |
312 | giveup_fpu(child); | |
313 | preempt_enable(); | |
314 | tmp = ((unsigned long *)child->thread.fpr)[index - PT_FPR0]; | |
315 | } | |
316 | ret = put_user(tmp,(unsigned long __user *) data); | |
317 | break; | |
318 | } | |
319 | ||
320 | /* If I and D space are separate, this will have to be fixed. */ | |
321 | case PTRACE_POKETEXT: /* write the word at location addr. */ | |
322 | case PTRACE_POKEDATA: | |
323 | ret = 0; | |
324 | if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data)) | |
325 | break; | |
326 | ret = -EIO; | |
327 | break; | |
328 | ||
329 | /* write the word at location addr in the USER area */ | |
330 | case PTRACE_POKEUSR: { | |
331 | unsigned long index; | |
332 | ||
333 | ret = -EIO; | |
334 | /* convert to index and check */ | |
335 | index = (unsigned long) addr >> 2; | |
336 | if ((addr & 3) || index > PT_FPSCR | |
337 | || child->thread.regs == NULL) | |
338 | break; | |
339 | ||
340 | CHECK_FULL_REGS(child->thread.regs); | |
341 | if (index == PT_ORIG_R3) | |
342 | break; | |
343 | if (index < PT_FPR0) { | |
344 | ret = put_reg(child, index, data); | |
345 | } else { | |
346 | preempt_disable(); | |
347 | if (child->thread.regs->msr & MSR_FP) | |
348 | giveup_fpu(child); | |
349 | preempt_enable(); | |
350 | ((unsigned long *)child->thread.fpr)[index - PT_FPR0] = data; | |
351 | ret = 0; | |
352 | } | |
353 | break; | |
354 | } | |
355 | ||
356 | case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ | |
357 | case PTRACE_CONT: { /* restart after signal. */ | |
358 | ret = -EIO; | |
359 | if ((unsigned long) data > _NSIG) | |
360 | break; | |
361 | if (request == PTRACE_SYSCALL) { | |
362 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
363 | } else { | |
364 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
365 | } | |
366 | child->exit_code = data; | |
367 | /* make sure the single step bit is not set. */ | |
368 | clear_single_step(child); | |
369 | wake_up_process(child); | |
370 | ret = 0; | |
371 | break; | |
372 | } | |
373 | ||
374 | /* | |
375 | * make the child exit. Best I can do is send it a sigkill. | |
376 | * perhaps it should be put in the status that it wants to | |
377 | * exit. | |
378 | */ | |
379 | case PTRACE_KILL: { | |
380 | ret = 0; | |
381 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ | |
382 | break; | |
383 | child->exit_code = SIGKILL; | |
384 | /* make sure the single step bit is not set. */ | |
385 | clear_single_step(child); | |
386 | wake_up_process(child); | |
387 | break; | |
388 | } | |
389 | ||
390 | case PTRACE_SINGLESTEP: { /* set the trap flag. */ | |
391 | ret = -EIO; | |
392 | if ((unsigned long) data > _NSIG) | |
393 | break; | |
394 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
395 | set_single_step(child); | |
396 | child->exit_code = data; | |
397 | /* give it a chance to run. */ | |
398 | wake_up_process(child); | |
399 | ret = 0; | |
400 | break; | |
401 | } | |
402 | ||
403 | case PTRACE_DETACH: | |
404 | ret = ptrace_detach(child, data); | |
405 | break; | |
406 | ||
407 | #ifdef CONFIG_ALTIVEC | |
408 | case PTRACE_GETVRREGS: | |
409 | /* Get the child altivec register state. */ | |
410 | preempt_disable(); | |
411 | if (child->thread.regs->msr & MSR_VEC) | |
412 | giveup_altivec(child); | |
413 | preempt_enable(); | |
414 | ret = get_vrregs((unsigned long __user *)data, child); | |
415 | break; | |
416 | ||
417 | case PTRACE_SETVRREGS: | |
418 | /* Set the child altivec register state. */ | |
419 | /* this is to clear the MSR_VEC bit to force a reload | |
420 | * of register state from memory */ | |
421 | preempt_disable(); | |
422 | if (child->thread.regs->msr & MSR_VEC) | |
423 | giveup_altivec(child); | |
424 | preempt_enable(); | |
425 | ret = set_vrregs(child, (unsigned long __user *)data); | |
426 | break; | |
427 | #endif | |
428 | #ifdef CONFIG_SPE | |
429 | case PTRACE_GETEVRREGS: | |
430 | /* Get the child spe register state. */ | |
431 | if (child->thread.regs->msr & MSR_SPE) | |
432 | giveup_spe(child); | |
433 | ret = get_evrregs((unsigned long __user *)data, child); | |
434 | break; | |
435 | ||
436 | case PTRACE_SETEVRREGS: | |
437 | /* Set the child spe register state. */ | |
438 | /* this is to clear the MSR_SPE bit to force a reload | |
439 | * of register state from memory */ | |
440 | if (child->thread.regs->msr & MSR_SPE) | |
441 | giveup_spe(child); | |
442 | ret = set_evrregs(child, (unsigned long __user *)data); | |
443 | break; | |
444 | #endif | |
445 | ||
446 | default: | |
447 | ret = ptrace_request(child, request, addr, data); | |
448 | break; | |
449 | } | |
450 | out_tsk: | |
451 | put_task_struct(child); | |
452 | out: | |
453 | unlock_kernel(); | |
454 | return ret; | |
455 | } | |
456 | ||
457 | void do_syscall_trace(void) | |
458 | { | |
459 | if (!test_thread_flag(TIF_SYSCALL_TRACE) | |
460 | || !(current->ptrace & PT_PTRACED)) | |
461 | return; | |
462 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) | |
463 | ? 0x80 : 0)); | |
464 | ||
465 | /* | |
466 | * this isn't the same as continuing with a signal, but it will do | |
467 | * for normal use. strace only continues with a signal if the | |
468 | * stopping signal is not SIGTRAP. -brl | |
469 | */ | |
470 | if (current->exit_code) { | |
471 | send_sig(current->exit_code, current, 1); | |
472 | current->exit_code = 0; | |
473 | } | |
474 | } |