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1da177e4 LT |
1 | /* |
2 | * arch/s390/kernel/ptrace.c | |
3 | * | |
4 | * S390 version | |
5 | * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation | |
6 | * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), | |
7 | * Martin Schwidefsky (schwidefsky@de.ibm.com) | |
8 | * | |
9 | * Based on PowerPC version | |
10 | * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) | |
11 | * | |
12 | * Derived from "arch/m68k/kernel/ptrace.c" | |
13 | * Copyright (C) 1994 by Hamish Macdonald | |
14 | * Taken from linux/kernel/ptrace.c and modified for M680x0. | |
15 | * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds | |
16 | * | |
17 | * Modified by Cort Dougan (cort@cs.nmt.edu) | |
18 | * | |
19 | * | |
20 | * This file is subject to the terms and conditions of the GNU General | |
21 | * Public License. See the file README.legal in the main directory of | |
22 | * this archive for more details. | |
23 | */ | |
24 | ||
25 | #include <linux/kernel.h> | |
26 | #include <linux/sched.h> | |
27 | #include <linux/mm.h> | |
28 | #include <linux/smp.h> | |
29 | #include <linux/smp_lock.h> | |
30 | #include <linux/errno.h> | |
31 | #include <linux/ptrace.h> | |
32 | #include <linux/user.h> | |
33 | #include <linux/security.h> | |
34 | #include <linux/audit.h> | |
35 | ||
36 | #include <asm/segment.h> | |
37 | #include <asm/page.h> | |
38 | #include <asm/pgtable.h> | |
39 | #include <asm/pgalloc.h> | |
40 | #include <asm/system.h> | |
41 | #include <asm/uaccess.h> | |
42 | ||
43 | #ifdef CONFIG_S390_SUPPORT | |
44 | #include "compat_ptrace.h" | |
45 | #endif | |
46 | ||
47 | static void | |
48 | FixPerRegisters(struct task_struct *task) | |
49 | { | |
50 | struct pt_regs *regs; | |
51 | per_struct *per_info; | |
52 | ||
53 | regs = __KSTK_PTREGS(task); | |
54 | per_info = (per_struct *) &task->thread.per_info; | |
55 | per_info->control_regs.bits.em_instruction_fetch = | |
56 | per_info->single_step | per_info->instruction_fetch; | |
57 | ||
58 | if (per_info->single_step) { | |
59 | per_info->control_regs.bits.starting_addr = 0; | |
60 | #ifdef CONFIG_S390_SUPPORT | |
61 | if (test_thread_flag(TIF_31BIT)) | |
62 | per_info->control_regs.bits.ending_addr = 0x7fffffffUL; | |
63 | else | |
64 | #endif | |
65 | per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN; | |
66 | } else { | |
67 | per_info->control_regs.bits.starting_addr = | |
68 | per_info->starting_addr; | |
69 | per_info->control_regs.bits.ending_addr = | |
70 | per_info->ending_addr; | |
71 | } | |
72 | /* | |
73 | * if any of the control reg tracing bits are on | |
74 | * we switch on per in the psw | |
75 | */ | |
76 | if (per_info->control_regs.words.cr[0] & PER_EM_MASK) | |
77 | regs->psw.mask |= PSW_MASK_PER; | |
78 | else | |
79 | regs->psw.mask &= ~PSW_MASK_PER; | |
80 | ||
81 | if (per_info->control_regs.bits.em_storage_alteration) | |
82 | per_info->control_regs.bits.storage_alt_space_ctl = 1; | |
83 | else | |
84 | per_info->control_regs.bits.storage_alt_space_ctl = 0; | |
85 | } | |
86 | ||
87 | void | |
88 | set_single_step(struct task_struct *task) | |
89 | { | |
90 | task->thread.per_info.single_step = 1; | |
91 | FixPerRegisters(task); | |
92 | } | |
93 | ||
94 | void | |
95 | clear_single_step(struct task_struct *task) | |
96 | { | |
97 | task->thread.per_info.single_step = 0; | |
98 | FixPerRegisters(task); | |
99 | } | |
100 | ||
101 | /* | |
102 | * Called by kernel/ptrace.c when detaching.. | |
103 | * | |
104 | * Make sure single step bits etc are not set. | |
105 | */ | |
106 | void | |
107 | ptrace_disable(struct task_struct *child) | |
108 | { | |
109 | /* make sure the single step bit is not set. */ | |
110 | clear_single_step(child); | |
111 | } | |
112 | ||
113 | #ifndef CONFIG_ARCH_S390X | |
114 | # define __ADDR_MASK 3 | |
115 | #else | |
116 | # define __ADDR_MASK 7 | |
117 | #endif | |
118 | ||
119 | /* | |
120 | * Read the word at offset addr from the user area of a process. The | |
121 | * trouble here is that the information is littered over different | |
122 | * locations. The process registers are found on the kernel stack, | |
123 | * the floating point stuff and the trace settings are stored in | |
124 | * the task structure. In addition the different structures in | |
125 | * struct user contain pad bytes that should be read as zeroes. | |
126 | * Lovely... | |
127 | */ | |
128 | static int | |
129 | peek_user(struct task_struct *child, addr_t addr, addr_t data) | |
130 | { | |
131 | struct user *dummy = NULL; | |
132 | addr_t offset, tmp; | |
133 | ||
134 | /* | |
135 | * Stupid gdb peeks/pokes the access registers in 64 bit with | |
136 | * an alignment of 4. Programmers from hell... | |
137 | */ | |
138 | if ((addr & 3) || addr > sizeof(struct user) - __ADDR_MASK) | |
139 | return -EIO; | |
140 | ||
141 | if (addr < (addr_t) &dummy->regs.acrs) { | |
142 | /* | |
143 | * psw and gprs are stored on the stack | |
144 | */ | |
145 | tmp = *(addr_t *)((addr_t) &__KSTK_PTREGS(child)->psw + addr); | |
146 | if (addr == (addr_t) &dummy->regs.psw.mask) | |
147 | /* Remove per bit from user psw. */ | |
148 | tmp &= ~PSW_MASK_PER; | |
149 | ||
150 | } else if (addr < (addr_t) &dummy->regs.orig_gpr2) { | |
151 | /* | |
152 | * access registers are stored in the thread structure | |
153 | */ | |
154 | offset = addr - (addr_t) &dummy->regs.acrs; | |
155 | tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset); | |
156 | ||
157 | } else if (addr == (addr_t) &dummy->regs.orig_gpr2) { | |
158 | /* | |
159 | * orig_gpr2 is stored on the kernel stack | |
160 | */ | |
161 | tmp = (addr_t) __KSTK_PTREGS(child)->orig_gpr2; | |
162 | ||
163 | } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) { | |
164 | /* | |
165 | * floating point regs. are stored in the thread structure | |
166 | */ | |
167 | offset = addr - (addr_t) &dummy->regs.fp_regs; | |
168 | tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset); | |
169 | ||
170 | } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) { | |
171 | /* | |
172 | * per_info is found in the thread structure | |
173 | */ | |
174 | offset = addr - (addr_t) &dummy->regs.per_info; | |
175 | tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset); | |
176 | ||
177 | } else | |
178 | tmp = 0; | |
179 | ||
180 | return put_user(tmp, (addr_t __user *) data); | |
181 | } | |
182 | ||
183 | /* | |
184 | * Write a word to the user area of a process at location addr. This | |
185 | * operation does have an additional problem compared to peek_user. | |
186 | * Stores to the program status word and on the floating point | |
187 | * control register needs to get checked for validity. | |
188 | */ | |
189 | static int | |
190 | poke_user(struct task_struct *child, addr_t addr, addr_t data) | |
191 | { | |
192 | struct user *dummy = NULL; | |
193 | addr_t offset; | |
194 | ||
195 | /* | |
196 | * Stupid gdb peeks/pokes the access registers in 64 bit with | |
197 | * an alignment of 4. Programmers from hell indeed... | |
198 | */ | |
199 | if ((addr & 3) || addr > sizeof(struct user) - __ADDR_MASK) | |
200 | return -EIO; | |
201 | ||
202 | if (addr < (addr_t) &dummy->regs.acrs) { | |
203 | /* | |
204 | * psw and gprs are stored on the stack | |
205 | */ | |
206 | if (addr == (addr_t) &dummy->regs.psw.mask && | |
207 | #ifdef CONFIG_S390_SUPPORT | |
208 | data != PSW_MASK_MERGE(PSW_USER32_BITS, data) && | |
209 | #endif | |
210 | data != PSW_MASK_MERGE(PSW_USER_BITS, data)) | |
211 | /* Invalid psw mask. */ | |
212 | return -EINVAL; | |
213 | #ifndef CONFIG_ARCH_S390X | |
214 | if (addr == (addr_t) &dummy->regs.psw.addr) | |
215 | /* I'd like to reject addresses without the | |
216 | high order bit but older gdb's rely on it */ | |
217 | data |= PSW_ADDR_AMODE; | |
218 | #endif | |
219 | *(addr_t *)((addr_t) &__KSTK_PTREGS(child)->psw + addr) = data; | |
220 | ||
221 | } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) { | |
222 | /* | |
223 | * access registers are stored in the thread structure | |
224 | */ | |
225 | offset = addr - (addr_t) &dummy->regs.acrs; | |
226 | *(addr_t *)((addr_t) &child->thread.acrs + offset) = data; | |
227 | ||
228 | } else if (addr == (addr_t) &dummy->regs.orig_gpr2) { | |
229 | /* | |
230 | * orig_gpr2 is stored on the kernel stack | |
231 | */ | |
232 | __KSTK_PTREGS(child)->orig_gpr2 = data; | |
233 | ||
234 | } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) { | |
235 | /* | |
236 | * floating point regs. are stored in the thread structure | |
237 | */ | |
238 | if (addr == (addr_t) &dummy->regs.fp_regs.fpc && | |
239 | (data & ~FPC_VALID_MASK) != 0) | |
240 | return -EINVAL; | |
241 | offset = addr - (addr_t) &dummy->regs.fp_regs; | |
242 | *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data; | |
243 | ||
244 | } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) { | |
245 | /* | |
246 | * per_info is found in the thread structure | |
247 | */ | |
248 | offset = addr - (addr_t) &dummy->regs.per_info; | |
249 | *(addr_t *)((addr_t) &child->thread.per_info + offset) = data; | |
250 | ||
251 | } | |
252 | ||
253 | FixPerRegisters(child); | |
254 | return 0; | |
255 | } | |
256 | ||
257 | static int | |
258 | do_ptrace_normal(struct task_struct *child, long request, long addr, long data) | |
259 | { | |
260 | unsigned long tmp; | |
261 | ptrace_area parea; | |
262 | int copied, ret; | |
263 | ||
264 | switch (request) { | |
265 | case PTRACE_PEEKTEXT: | |
266 | case PTRACE_PEEKDATA: | |
267 | /* Remove high order bit from address (only for 31 bit). */ | |
268 | addr &= PSW_ADDR_INSN; | |
269 | /* read word at location addr. */ | |
270 | copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); | |
271 | if (copied != sizeof(tmp)) | |
272 | return -EIO; | |
273 | return put_user(tmp, (unsigned long __user *) data); | |
274 | ||
275 | case PTRACE_PEEKUSR: | |
276 | /* read the word at location addr in the USER area. */ | |
277 | return peek_user(child, addr, data); | |
278 | ||
279 | case PTRACE_POKETEXT: | |
280 | case PTRACE_POKEDATA: | |
281 | /* Remove high order bit from address (only for 31 bit). */ | |
282 | addr &= PSW_ADDR_INSN; | |
283 | /* write the word at location addr. */ | |
284 | copied = access_process_vm(child, addr, &data, sizeof(data),1); | |
285 | if (copied != sizeof(data)) | |
286 | return -EIO; | |
287 | return 0; | |
288 | ||
289 | case PTRACE_POKEUSR: | |
290 | /* write the word at location addr in the USER area */ | |
291 | return poke_user(child, addr, data); | |
292 | ||
293 | case PTRACE_PEEKUSR_AREA: | |
294 | case PTRACE_POKEUSR_AREA: | |
295 | if (copy_from_user(&parea, (void __user *) addr, | |
296 | sizeof(parea))) | |
297 | return -EFAULT; | |
298 | addr = parea.kernel_addr; | |
299 | data = parea.process_addr; | |
300 | copied = 0; | |
301 | while (copied < parea.len) { | |
302 | if (request == PTRACE_PEEKUSR_AREA) | |
303 | ret = peek_user(child, addr, data); | |
304 | else { | |
305 | addr_t tmp; | |
306 | if (get_user (tmp, (addr_t __user *) data)) | |
307 | return -EFAULT; | |
308 | ret = poke_user(child, addr, tmp); | |
309 | } | |
310 | if (ret) | |
311 | return ret; | |
312 | addr += sizeof(unsigned long); | |
313 | data += sizeof(unsigned long); | |
314 | copied += sizeof(unsigned long); | |
315 | } | |
316 | return 0; | |
317 | } | |
318 | return ptrace_request(child, request, addr, data); | |
319 | } | |
320 | ||
321 | #ifdef CONFIG_S390_SUPPORT | |
322 | /* | |
323 | * Now the fun part starts... a 31 bit program running in the | |
324 | * 31 bit emulation tracing another program. PTRACE_PEEKTEXT, | |
325 | * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy | |
326 | * to handle, the difference to the 64 bit versions of the requests | |
327 | * is that the access is done in multiples of 4 byte instead of | |
328 | * 8 bytes (sizeof(unsigned long) on 31/64 bit). | |
329 | * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA, | |
330 | * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program | |
331 | * is a 31 bit program too, the content of struct user can be | |
332 | * emulated. A 31 bit program peeking into the struct user of | |
333 | * a 64 bit program is a no-no. | |
334 | */ | |
335 | ||
336 | /* | |
337 | * Same as peek_user but for a 31 bit program. | |
338 | */ | |
339 | static int | |
340 | peek_user_emu31(struct task_struct *child, addr_t addr, addr_t data) | |
341 | { | |
342 | struct user32 *dummy32 = NULL; | |
343 | per_struct32 *dummy_per32 = NULL; | |
344 | addr_t offset; | |
345 | __u32 tmp; | |
346 | ||
347 | if (!test_thread_flag(TIF_31BIT) || | |
348 | (addr & 3) || addr > sizeof(struct user) - 3) | |
349 | return -EIO; | |
350 | ||
351 | if (addr < (addr_t) &dummy32->regs.acrs) { | |
352 | /* | |
353 | * psw and gprs are stored on the stack | |
354 | */ | |
355 | if (addr == (addr_t) &dummy32->regs.psw.mask) { | |
356 | /* Fake a 31 bit psw mask. */ | |
357 | tmp = (__u32)(__KSTK_PTREGS(child)->psw.mask >> 32); | |
358 | tmp = PSW32_MASK_MERGE(PSW32_USER_BITS, tmp); | |
359 | } else if (addr == (addr_t) &dummy32->regs.psw.addr) { | |
360 | /* Fake a 31 bit psw address. */ | |
361 | tmp = (__u32) __KSTK_PTREGS(child)->psw.addr | | |
362 | PSW32_ADDR_AMODE31; | |
363 | } else { | |
364 | /* gpr 0-15 */ | |
365 | tmp = *(__u32 *)((addr_t) &__KSTK_PTREGS(child)->psw + | |
366 | addr*2 + 4); | |
367 | } | |
368 | } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) { | |
369 | /* | |
370 | * access registers are stored in the thread structure | |
371 | */ | |
372 | offset = addr - (addr_t) &dummy32->regs.acrs; | |
373 | tmp = *(__u32*)((addr_t) &child->thread.acrs + offset); | |
374 | ||
375 | } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) { | |
376 | /* | |
377 | * orig_gpr2 is stored on the kernel stack | |
378 | */ | |
379 | tmp = *(__u32*)((addr_t) &__KSTK_PTREGS(child)->orig_gpr2 + 4); | |
380 | ||
381 | } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) { | |
382 | /* | |
383 | * floating point regs. are stored in the thread structure | |
384 | */ | |
385 | offset = addr - (addr_t) &dummy32->regs.fp_regs; | |
386 | tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset); | |
387 | ||
388 | } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) { | |
389 | /* | |
390 | * per_info is found in the thread structure | |
391 | */ | |
392 | offset = addr - (addr_t) &dummy32->regs.per_info; | |
393 | /* This is magic. See per_struct and per_struct32. */ | |
394 | if ((offset >= (addr_t) &dummy_per32->control_regs && | |
395 | offset < (addr_t) (&dummy_per32->control_regs + 1)) || | |
396 | (offset >= (addr_t) &dummy_per32->starting_addr && | |
397 | offset <= (addr_t) &dummy_per32->ending_addr) || | |
398 | offset == (addr_t) &dummy_per32->lowcore.words.address) | |
399 | offset = offset*2 + 4; | |
400 | else | |
401 | offset = offset*2; | |
402 | tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset); | |
403 | ||
404 | } else | |
405 | tmp = 0; | |
406 | ||
407 | return put_user(tmp, (__u32 __user *) data); | |
408 | } | |
409 | ||
410 | /* | |
411 | * Same as poke_user but for a 31 bit program. | |
412 | */ | |
413 | static int | |
414 | poke_user_emu31(struct task_struct *child, addr_t addr, addr_t data) | |
415 | { | |
416 | struct user32 *dummy32 = NULL; | |
417 | per_struct32 *dummy_per32 = NULL; | |
418 | addr_t offset; | |
419 | __u32 tmp; | |
420 | ||
421 | if (!test_thread_flag(TIF_31BIT) || | |
422 | (addr & 3) || addr > sizeof(struct user32) - 3) | |
423 | return -EIO; | |
424 | ||
425 | tmp = (__u32) data; | |
426 | ||
427 | if (addr < (addr_t) &dummy32->regs.acrs) { | |
428 | /* | |
429 | * psw, gprs, acrs and orig_gpr2 are stored on the stack | |
430 | */ | |
431 | if (addr == (addr_t) &dummy32->regs.psw.mask) { | |
432 | /* Build a 64 bit psw mask from 31 bit mask. */ | |
433 | if (tmp != PSW32_MASK_MERGE(PSW32_USER_BITS, tmp)) | |
434 | /* Invalid psw mask. */ | |
435 | return -EINVAL; | |
436 | __KSTK_PTREGS(child)->psw.mask = | |
437 | PSW_MASK_MERGE(PSW_USER32_BITS, (__u64) tmp << 32); | |
438 | } else if (addr == (addr_t) &dummy32->regs.psw.addr) { | |
439 | /* Build a 64 bit psw address from 31 bit address. */ | |
440 | __KSTK_PTREGS(child)->psw.addr = | |
441 | (__u64) tmp & PSW32_ADDR_INSN; | |
442 | } else { | |
443 | /* gpr 0-15 */ | |
444 | *(__u32*)((addr_t) &__KSTK_PTREGS(child)->psw | |
445 | + addr*2 + 4) = tmp; | |
446 | } | |
447 | } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) { | |
448 | /* | |
449 | * access registers are stored in the thread structure | |
450 | */ | |
451 | offset = addr - (addr_t) &dummy32->regs.acrs; | |
452 | *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp; | |
453 | ||
454 | } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) { | |
455 | /* | |
456 | * orig_gpr2 is stored on the kernel stack | |
457 | */ | |
458 | *(__u32*)((addr_t) &__KSTK_PTREGS(child)->orig_gpr2 + 4) = tmp; | |
459 | ||
460 | } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) { | |
461 | /* | |
462 | * floating point regs. are stored in the thread structure | |
463 | */ | |
464 | if (addr == (addr_t) &dummy32->regs.fp_regs.fpc && | |
465 | (tmp & ~FPC_VALID_MASK) != 0) | |
466 | /* Invalid floating point control. */ | |
467 | return -EINVAL; | |
468 | offset = addr - (addr_t) &dummy32->regs.fp_regs; | |
469 | *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp; | |
470 | ||
471 | } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) { | |
472 | /* | |
473 | * per_info is found in the thread structure. | |
474 | */ | |
475 | offset = addr - (addr_t) &dummy32->regs.per_info; | |
476 | /* | |
477 | * This is magic. See per_struct and per_struct32. | |
478 | * By incident the offsets in per_struct are exactly | |
479 | * twice the offsets in per_struct32 for all fields. | |
480 | * The 8 byte fields need special handling though, | |
481 | * because the second half (bytes 4-7) is needed and | |
482 | * not the first half. | |
483 | */ | |
484 | if ((offset >= (addr_t) &dummy_per32->control_regs && | |
485 | offset < (addr_t) (&dummy_per32->control_regs + 1)) || | |
486 | (offset >= (addr_t) &dummy_per32->starting_addr && | |
487 | offset <= (addr_t) &dummy_per32->ending_addr) || | |
488 | offset == (addr_t) &dummy_per32->lowcore.words.address) | |
489 | offset = offset*2 + 4; | |
490 | else | |
491 | offset = offset*2; | |
492 | *(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp; | |
493 | ||
494 | } | |
495 | ||
496 | FixPerRegisters(child); | |
497 | return 0; | |
498 | } | |
499 | ||
500 | static int | |
501 | do_ptrace_emu31(struct task_struct *child, long request, long addr, long data) | |
502 | { | |
503 | unsigned int tmp; /* 4 bytes !! */ | |
504 | ptrace_area_emu31 parea; | |
505 | int copied, ret; | |
506 | ||
507 | switch (request) { | |
508 | case PTRACE_PEEKTEXT: | |
509 | case PTRACE_PEEKDATA: | |
510 | /* read word at location addr. */ | |
511 | copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); | |
512 | if (copied != sizeof(tmp)) | |
513 | return -EIO; | |
514 | return put_user(tmp, (unsigned int __user *) data); | |
515 | ||
516 | case PTRACE_PEEKUSR: | |
517 | /* read the word at location addr in the USER area. */ | |
518 | return peek_user_emu31(child, addr, data); | |
519 | ||
520 | case PTRACE_POKETEXT: | |
521 | case PTRACE_POKEDATA: | |
522 | /* write the word at location addr. */ | |
523 | tmp = data; | |
524 | copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 1); | |
525 | if (copied != sizeof(tmp)) | |
526 | return -EIO; | |
527 | return 0; | |
528 | ||
529 | case PTRACE_POKEUSR: | |
530 | /* write the word at location addr in the USER area */ | |
531 | return poke_user_emu31(child, addr, data); | |
532 | ||
533 | case PTRACE_PEEKUSR_AREA: | |
534 | case PTRACE_POKEUSR_AREA: | |
535 | if (copy_from_user(&parea, (void __user *) addr, | |
536 | sizeof(parea))) | |
537 | return -EFAULT; | |
538 | addr = parea.kernel_addr; | |
539 | data = parea.process_addr; | |
540 | copied = 0; | |
541 | while (copied < parea.len) { | |
542 | if (request == PTRACE_PEEKUSR_AREA) | |
543 | ret = peek_user_emu31(child, addr, data); | |
544 | else { | |
545 | __u32 tmp; | |
546 | if (get_user (tmp, (__u32 __user *) data)) | |
547 | return -EFAULT; | |
548 | ret = poke_user_emu31(child, addr, tmp); | |
549 | } | |
550 | if (ret) | |
551 | return ret; | |
552 | addr += sizeof(unsigned int); | |
553 | data += sizeof(unsigned int); | |
554 | copied += sizeof(unsigned int); | |
555 | } | |
556 | return 0; | |
557 | case PTRACE_GETEVENTMSG: | |
558 | return put_user((__u32) child->ptrace_message, | |
559 | (unsigned int __user *) data); | |
560 | case PTRACE_GETSIGINFO: | |
561 | if (child->last_siginfo == NULL) | |
562 | return -EINVAL; | |
563 | return copy_siginfo_to_user32((compat_siginfo_t __user *) data, | |
564 | child->last_siginfo); | |
565 | case PTRACE_SETSIGINFO: | |
566 | if (child->last_siginfo == NULL) | |
567 | return -EINVAL; | |
568 | return copy_siginfo_from_user32(child->last_siginfo, | |
569 | (compat_siginfo_t __user *) data); | |
570 | } | |
571 | return ptrace_request(child, request, addr, data); | |
572 | } | |
573 | #endif | |
574 | ||
575 | #define PT32_IEEE_IP 0x13c | |
576 | ||
577 | static int | |
578 | do_ptrace(struct task_struct *child, long request, long addr, long data) | |
579 | { | |
580 | int ret; | |
581 | ||
582 | if (request == PTRACE_ATTACH) | |
583 | return ptrace_attach(child); | |
584 | ||
585 | /* | |
586 | * Special cases to get/store the ieee instructions pointer. | |
587 | */ | |
588 | if (child == current) { | |
589 | if (request == PTRACE_PEEKUSR && addr == PT_IEEE_IP) | |
590 | return peek_user(child, addr, data); | |
591 | if (request == PTRACE_POKEUSR && addr == PT_IEEE_IP) | |
592 | return poke_user(child, addr, data); | |
593 | #ifdef CONFIG_S390_SUPPORT | |
594 | if (request == PTRACE_PEEKUSR && | |
595 | addr == PT32_IEEE_IP && test_thread_flag(TIF_31BIT)) | |
596 | return peek_user_emu31(child, addr, data); | |
597 | if (request == PTRACE_POKEUSR && | |
598 | addr == PT32_IEEE_IP && test_thread_flag(TIF_31BIT)) | |
599 | return poke_user_emu31(child, addr, data); | |
600 | #endif | |
601 | } | |
602 | ||
603 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
604 | if (ret < 0) | |
605 | return ret; | |
606 | ||
607 | switch (request) { | |
608 | case PTRACE_SYSCALL: | |
609 | /* continue and stop at next (return from) syscall */ | |
610 | case PTRACE_CONT: | |
611 | /* restart after signal. */ | |
612 | if ((unsigned long) data >= _NSIG) | |
613 | return -EIO; | |
614 | if (request == PTRACE_SYSCALL) | |
615 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
616 | else | |
617 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
618 | child->exit_code = data; | |
619 | /* make sure the single step bit is not set. */ | |
620 | clear_single_step(child); | |
621 | wake_up_process(child); | |
622 | return 0; | |
623 | ||
624 | case PTRACE_KILL: | |
625 | /* | |
626 | * make the child exit. Best I can do is send it a sigkill. | |
627 | * perhaps it should be put in the status that it wants to | |
628 | * exit. | |
629 | */ | |
630 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ | |
631 | return 0; | |
632 | child->exit_code = SIGKILL; | |
633 | /* make sure the single step bit is not set. */ | |
634 | clear_single_step(child); | |
635 | wake_up_process(child); | |
636 | return 0; | |
637 | ||
638 | case PTRACE_SINGLESTEP: | |
639 | /* set the trap flag. */ | |
640 | if ((unsigned long) data >= _NSIG) | |
641 | return -EIO; | |
642 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
643 | child->exit_code = data; | |
644 | if (data) | |
645 | set_tsk_thread_flag(child, TIF_SINGLE_STEP); | |
646 | else | |
647 | set_single_step(child); | |
648 | /* give it a chance to run. */ | |
649 | wake_up_process(child); | |
650 | return 0; | |
651 | ||
652 | case PTRACE_DETACH: | |
653 | /* detach a process that was attached. */ | |
654 | return ptrace_detach(child, data); | |
655 | ||
656 | ||
657 | /* Do requests that differ for 31/64 bit */ | |
658 | default: | |
659 | #ifdef CONFIG_S390_SUPPORT | |
660 | if (test_thread_flag(TIF_31BIT)) | |
661 | return do_ptrace_emu31(child, request, addr, data); | |
662 | #endif | |
663 | return do_ptrace_normal(child, request, addr, data); | |
664 | } | |
665 | /* Not reached. */ | |
666 | return -EIO; | |
667 | } | |
668 | ||
669 | asmlinkage long | |
670 | sys_ptrace(long request, long pid, long addr, long data) | |
671 | { | |
672 | struct task_struct *child; | |
673 | int ret; | |
674 | ||
675 | lock_kernel(); | |
676 | ||
677 | if (request == PTRACE_TRACEME) { | |
678 | /* are we already being traced? */ | |
679 | ret = -EPERM; | |
680 | if (current->ptrace & PT_PTRACED) | |
681 | goto out; | |
682 | ret = security_ptrace(current->parent, current); | |
683 | if (ret) | |
684 | goto out; | |
685 | /* set the ptrace bit in the process flags. */ | |
686 | current->ptrace |= PT_PTRACED; | |
687 | goto out; | |
688 | } | |
689 | ||
690 | ret = -EPERM; | |
691 | if (pid == 1) /* you may not mess with init */ | |
692 | goto out; | |
693 | ||
694 | ret = -ESRCH; | |
695 | read_lock(&tasklist_lock); | |
696 | child = find_task_by_pid(pid); | |
697 | if (child) | |
698 | get_task_struct(child); | |
699 | read_unlock(&tasklist_lock); | |
700 | if (!child) | |
701 | goto out; | |
702 | ||
703 | ret = do_ptrace(child, request, addr, data); | |
704 | ||
705 | put_task_struct(child); | |
706 | out: | |
707 | unlock_kernel(); | |
708 | return ret; | |
709 | } | |
710 | ||
711 | asmlinkage void | |
712 | syscall_trace(struct pt_regs *regs, int entryexit) | |
713 | { | |
714 | if (unlikely(current->audit_context)) { | |
715 | if (!entryexit) | |
716 | audit_syscall_entry(current, regs->gprs[2], | |
717 | regs->orig_gpr2, regs->gprs[3], | |
718 | regs->gprs[4], regs->gprs[5]); | |
719 | else | |
720 | audit_syscall_exit(current, regs->gprs[2]); | |
721 | } | |
722 | if (!test_thread_flag(TIF_SYSCALL_TRACE)) | |
723 | return; | |
724 | if (!(current->ptrace & PT_PTRACED)) | |
725 | return; | |
726 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) | |
727 | ? 0x80 : 0)); | |
728 | ||
729 | /* | |
730 | * this isn't the same as continuing with a signal, but it will do | |
731 | * for normal use. strace only continues with a signal if the | |
732 | * stopping signal is not SIGTRAP. -brl | |
733 | */ | |
734 | if (current->exit_code) { | |
735 | send_sig(current->exit_code, current, 1); | |
736 | current->exit_code = 0; | |
737 | } | |
738 | } |