xref: /linux/arch/s390/kernel/ptrace.c (revision 40d3057ac036f2501c1930728a6179be4fca577b)
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 #include <linux/signal.h>
36 #include <linux/elf.h>
37 #include <linux/regset.h>
38 
39 #include <asm/segment.h>
40 #include <asm/page.h>
41 #include <asm/pgtable.h>
42 #include <asm/pgalloc.h>
43 #include <asm/system.h>
44 #include <asm/uaccess.h>
45 #include <asm/unistd.h>
46 #include "entry.h"
47 
48 #ifdef CONFIG_COMPAT
49 #include "compat_ptrace.h"
50 #endif
51 
52 enum s390_regset {
53 	REGSET_GENERAL,
54 	REGSET_FP,
55 };
56 
57 static void
58 FixPerRegisters(struct task_struct *task)
59 {
60 	struct pt_regs *regs;
61 	per_struct *per_info;
62 
63 	regs = task_pt_regs(task);
64 	per_info = (per_struct *) &task->thread.per_info;
65 	per_info->control_regs.bits.em_instruction_fetch =
66 		per_info->single_step | per_info->instruction_fetch;
67 
68 	if (per_info->single_step) {
69 		per_info->control_regs.bits.starting_addr = 0;
70 #ifdef CONFIG_COMPAT
71 		if (test_thread_flag(TIF_31BIT))
72 			per_info->control_regs.bits.ending_addr = 0x7fffffffUL;
73 		else
74 #endif
75 			per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN;
76 	} else {
77 		per_info->control_regs.bits.starting_addr =
78 			per_info->starting_addr;
79 		per_info->control_regs.bits.ending_addr =
80 			per_info->ending_addr;
81 	}
82 	/*
83 	 * if any of the control reg tracing bits are on
84 	 * we switch on per in the psw
85 	 */
86 	if (per_info->control_regs.words.cr[0] & PER_EM_MASK)
87 		regs->psw.mask |= PSW_MASK_PER;
88 	else
89 		regs->psw.mask &= ~PSW_MASK_PER;
90 
91 	if (per_info->control_regs.bits.em_storage_alteration)
92 		per_info->control_regs.bits.storage_alt_space_ctl = 1;
93 	else
94 		per_info->control_regs.bits.storage_alt_space_ctl = 0;
95 }
96 
97 void user_enable_single_step(struct task_struct *task)
98 {
99 	task->thread.per_info.single_step = 1;
100 	FixPerRegisters(task);
101 }
102 
103 void user_disable_single_step(struct task_struct *task)
104 {
105 	task->thread.per_info.single_step = 0;
106 	FixPerRegisters(task);
107 }
108 
109 /*
110  * Called by kernel/ptrace.c when detaching..
111  *
112  * Make sure single step bits etc are not set.
113  */
114 void
115 ptrace_disable(struct task_struct *child)
116 {
117 	/* make sure the single step bit is not set. */
118 	user_disable_single_step(child);
119 }
120 
121 #ifndef CONFIG_64BIT
122 # define __ADDR_MASK 3
123 #else
124 # define __ADDR_MASK 7
125 #endif
126 
127 /*
128  * Read the word at offset addr from the user area of a process. The
129  * trouble here is that the information is littered over different
130  * locations. The process registers are found on the kernel stack,
131  * the floating point stuff and the trace settings are stored in
132  * the task structure. In addition the different structures in
133  * struct user contain pad bytes that should be read as zeroes.
134  * Lovely...
135  */
136 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
137 {
138 	struct user *dummy = NULL;
139 	addr_t offset, tmp;
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) &task_pt_regs(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 #ifdef CONFIG_64BIT
156 		/*
157 		 * Very special case: old & broken 64 bit gdb reading
158 		 * from acrs[15]. Result is a 64 bit value. Read the
159 		 * 32 bit acrs[15] value and shift it by 32. Sick...
160 		 */
161 		if (addr == (addr_t) &dummy->regs.acrs[15])
162 			tmp = ((unsigned long) child->thread.acrs[15]) << 32;
163 		else
164 #endif
165 		tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
166 
167 	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
168 		/*
169 		 * orig_gpr2 is stored on the kernel stack
170 		 */
171 		tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
172 
173 	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
174 		/*
175 		 * prevent reads of padding hole between
176 		 * orig_gpr2 and fp_regs on s390.
177 		 */
178 		tmp = 0;
179 
180 	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
181 		/*
182 		 * floating point regs. are stored in the thread structure
183 		 */
184 		offset = addr - (addr_t) &dummy->regs.fp_regs;
185 		tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
186 		if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
187 			tmp &= (unsigned long) FPC_VALID_MASK
188 				<< (BITS_PER_LONG - 32);
189 
190 	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
191 		/*
192 		 * per_info is found in the thread structure
193 		 */
194 		offset = addr - (addr_t) &dummy->regs.per_info;
195 		tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset);
196 
197 	} else
198 		tmp = 0;
199 
200 	return tmp;
201 }
202 
203 static int
204 peek_user(struct task_struct *child, addr_t addr, addr_t data)
205 {
206 	struct user *dummy = NULL;
207 	addr_t tmp, mask;
208 
209 	/*
210 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
211 	 * an alignment of 4. Programmers from hell...
212 	 */
213 	mask = __ADDR_MASK;
214 #ifdef CONFIG_64BIT
215 	if (addr >= (addr_t) &dummy->regs.acrs &&
216 	    addr < (addr_t) &dummy->regs.orig_gpr2)
217 		mask = 3;
218 #endif
219 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
220 		return -EIO;
221 
222 	tmp = __peek_user(child, addr);
223 	return put_user(tmp, (addr_t __user *) data);
224 }
225 
226 /*
227  * Write a word to the user area of a process at location addr. This
228  * operation does have an additional problem compared to peek_user.
229  * Stores to the program status word and on the floating point
230  * control register needs to get checked for validity.
231  */
232 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
233 {
234 	struct user *dummy = NULL;
235 	addr_t offset;
236 
237 	if (addr < (addr_t) &dummy->regs.acrs) {
238 		/*
239 		 * psw and gprs are stored on the stack
240 		 */
241 		if (addr == (addr_t) &dummy->regs.psw.mask &&
242 #ifdef CONFIG_COMPAT
243 		    data != PSW_MASK_MERGE(psw_user32_bits, data) &&
244 #endif
245 		    data != PSW_MASK_MERGE(psw_user_bits, data))
246 			/* Invalid psw mask. */
247 			return -EINVAL;
248 #ifndef CONFIG_64BIT
249 		if (addr == (addr_t) &dummy->regs.psw.addr)
250 			/* I'd like to reject addresses without the
251 			   high order bit but older gdb's rely on it */
252 			data |= PSW_ADDR_AMODE;
253 #endif
254 		*(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
255 
256 	} else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
257 		/*
258 		 * access registers are stored in the thread structure
259 		 */
260 		offset = addr - (addr_t) &dummy->regs.acrs;
261 #ifdef CONFIG_64BIT
262 		/*
263 		 * Very special case: old & broken 64 bit gdb writing
264 		 * to acrs[15] with a 64 bit value. Ignore the lower
265 		 * half of the value and write the upper 32 bit to
266 		 * acrs[15]. Sick...
267 		 */
268 		if (addr == (addr_t) &dummy->regs.acrs[15])
269 			child->thread.acrs[15] = (unsigned int) (data >> 32);
270 		else
271 #endif
272 		*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
273 
274 	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
275 		/*
276 		 * orig_gpr2 is stored on the kernel stack
277 		 */
278 		task_pt_regs(child)->orig_gpr2 = data;
279 
280 	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
281 		/*
282 		 * prevent writes of padding hole between
283 		 * orig_gpr2 and fp_regs on s390.
284 		 */
285 		return 0;
286 
287 	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
288 		/*
289 		 * floating point regs. are stored in the thread structure
290 		 */
291 		if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
292 		    (data & ~((unsigned long) FPC_VALID_MASK
293 			      << (BITS_PER_LONG - 32))) != 0)
294 			return -EINVAL;
295 		offset = addr - (addr_t) &dummy->regs.fp_regs;
296 		*(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
297 
298 	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
299 		/*
300 		 * per_info is found in the thread structure
301 		 */
302 		offset = addr - (addr_t) &dummy->regs.per_info;
303 		*(addr_t *)((addr_t) &child->thread.per_info + offset) = data;
304 
305 	}
306 
307 	FixPerRegisters(child);
308 	return 0;
309 }
310 
311 static int
312 poke_user(struct task_struct *child, addr_t addr, addr_t data)
313 {
314 	struct user *dummy = NULL;
315 	addr_t mask;
316 
317 	/*
318 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
319 	 * an alignment of 4. Programmers from hell indeed...
320 	 */
321 	mask = __ADDR_MASK;
322 #ifdef CONFIG_64BIT
323 	if (addr >= (addr_t) &dummy->regs.acrs &&
324 	    addr < (addr_t) &dummy->regs.orig_gpr2)
325 		mask = 3;
326 #endif
327 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
328 		return -EIO;
329 
330 	return __poke_user(child, addr, data);
331 }
332 
333 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
334 {
335 	ptrace_area parea;
336 	int copied, ret;
337 
338 	switch (request) {
339 	case PTRACE_PEEKTEXT:
340 	case PTRACE_PEEKDATA:
341 		/* Remove high order bit from address (only for 31 bit). */
342 		addr &= PSW_ADDR_INSN;
343 		/* read word at location addr. */
344 		return generic_ptrace_peekdata(child, addr, data);
345 
346 	case PTRACE_PEEKUSR:
347 		/* read the word at location addr in the USER area. */
348 		return peek_user(child, addr, data);
349 
350 	case PTRACE_POKETEXT:
351 	case PTRACE_POKEDATA:
352 		/* Remove high order bit from address (only for 31 bit). */
353 		addr &= PSW_ADDR_INSN;
354 		/* write the word at location addr. */
355 		return generic_ptrace_pokedata(child, addr, data);
356 
357 	case PTRACE_POKEUSR:
358 		/* write the word at location addr in the USER area */
359 		return poke_user(child, addr, data);
360 
361 	case PTRACE_PEEKUSR_AREA:
362 	case PTRACE_POKEUSR_AREA:
363 		if (copy_from_user(&parea, (void __force __user *) addr,
364 							sizeof(parea)))
365 			return -EFAULT;
366 		addr = parea.kernel_addr;
367 		data = parea.process_addr;
368 		copied = 0;
369 		while (copied < parea.len) {
370 			if (request == PTRACE_PEEKUSR_AREA)
371 				ret = peek_user(child, addr, data);
372 			else {
373 				addr_t utmp;
374 				if (get_user(utmp,
375 					     (addr_t __force __user *) data))
376 					return -EFAULT;
377 				ret = poke_user(child, addr, utmp);
378 			}
379 			if (ret)
380 				return ret;
381 			addr += sizeof(unsigned long);
382 			data += sizeof(unsigned long);
383 			copied += sizeof(unsigned long);
384 		}
385 		return 0;
386 	}
387 	return ptrace_request(child, request, addr, data);
388 }
389 
390 #ifdef CONFIG_COMPAT
391 /*
392  * Now the fun part starts... a 31 bit program running in the
393  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
394  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
395  * to handle, the difference to the 64 bit versions of the requests
396  * is that the access is done in multiples of 4 byte instead of
397  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
398  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
399  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
400  * is a 31 bit program too, the content of struct user can be
401  * emulated. A 31 bit program peeking into the struct user of
402  * a 64 bit program is a no-no.
403  */
404 
405 /*
406  * Same as peek_user but for a 31 bit program.
407  */
408 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
409 {
410 	struct user32 *dummy32 = NULL;
411 	per_struct32 *dummy_per32 = NULL;
412 	addr_t offset;
413 	__u32 tmp;
414 
415 	if (addr < (addr_t) &dummy32->regs.acrs) {
416 		/*
417 		 * psw and gprs are stored on the stack
418 		 */
419 		if (addr == (addr_t) &dummy32->regs.psw.mask) {
420 			/* Fake a 31 bit psw mask. */
421 			tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
422 			tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
423 		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
424 			/* Fake a 31 bit psw address. */
425 			tmp = (__u32) task_pt_regs(child)->psw.addr |
426 				PSW32_ADDR_AMODE31;
427 		} else {
428 			/* gpr 0-15 */
429 			tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
430 					 addr*2 + 4);
431 		}
432 	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
433 		/*
434 		 * access registers are stored in the thread structure
435 		 */
436 		offset = addr - (addr_t) &dummy32->regs.acrs;
437 		tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
438 
439 	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
440 		/*
441 		 * orig_gpr2 is stored on the kernel stack
442 		 */
443 		tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
444 
445 	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
446 		/*
447 		 * prevent reads of padding hole between
448 		 * orig_gpr2 and fp_regs on s390.
449 		 */
450 		tmp = 0;
451 
452 	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
453 		/*
454 		 * floating point regs. are stored in the thread structure
455 		 */
456 	        offset = addr - (addr_t) &dummy32->regs.fp_regs;
457 		tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
458 
459 	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
460 		/*
461 		 * per_info is found in the thread structure
462 		 */
463 		offset = addr - (addr_t) &dummy32->regs.per_info;
464 		/* This is magic. See per_struct and per_struct32. */
465 		if ((offset >= (addr_t) &dummy_per32->control_regs &&
466 		     offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
467 		    (offset >= (addr_t) &dummy_per32->starting_addr &&
468 		     offset <= (addr_t) &dummy_per32->ending_addr) ||
469 		    offset == (addr_t) &dummy_per32->lowcore.words.address)
470 			offset = offset*2 + 4;
471 		else
472 			offset = offset*2;
473 		tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);
474 
475 	} else
476 		tmp = 0;
477 
478 	return tmp;
479 }
480 
481 static int peek_user_compat(struct task_struct *child,
482 			    addr_t addr, addr_t data)
483 {
484 	__u32 tmp;
485 
486 	if (!test_thread_flag(TIF_31BIT) ||
487 	    (addr & 3) || addr > sizeof(struct user) - 3)
488 		return -EIO;
489 
490 	tmp = __peek_user_compat(child, addr);
491 	return put_user(tmp, (__u32 __user *) data);
492 }
493 
494 /*
495  * Same as poke_user but for a 31 bit program.
496  */
497 static int __poke_user_compat(struct task_struct *child,
498 			      addr_t addr, addr_t data)
499 {
500 	struct user32 *dummy32 = NULL;
501 	per_struct32 *dummy_per32 = NULL;
502 	__u32 tmp = (__u32) data;
503 	addr_t offset;
504 
505 	if (addr < (addr_t) &dummy32->regs.acrs) {
506 		/*
507 		 * psw, gprs, acrs and orig_gpr2 are stored on the stack
508 		 */
509 		if (addr == (addr_t) &dummy32->regs.psw.mask) {
510 			/* Build a 64 bit psw mask from 31 bit mask. */
511 			if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
512 				/* Invalid psw mask. */
513 				return -EINVAL;
514 			task_pt_regs(child)->psw.mask =
515 				PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
516 		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
517 			/* Build a 64 bit psw address from 31 bit address. */
518 			task_pt_regs(child)->psw.addr =
519 				(__u64) tmp & PSW32_ADDR_INSN;
520 		} else {
521 			/* gpr 0-15 */
522 			*(__u32*)((addr_t) &task_pt_regs(child)->psw
523 				  + addr*2 + 4) = tmp;
524 		}
525 	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
526 		/*
527 		 * access registers are stored in the thread structure
528 		 */
529 		offset = addr - (addr_t) &dummy32->regs.acrs;
530 		*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
531 
532 	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
533 		/*
534 		 * orig_gpr2 is stored on the kernel stack
535 		 */
536 		*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
537 
538 	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
539 		/*
540 		 * prevent writess of padding hole between
541 		 * orig_gpr2 and fp_regs on s390.
542 		 */
543 		return 0;
544 
545 	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
546 		/*
547 		 * floating point regs. are stored in the thread structure
548 		 */
549 		if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
550 		    (tmp & ~FPC_VALID_MASK) != 0)
551 			/* Invalid floating point control. */
552 			return -EINVAL;
553 	        offset = addr - (addr_t) &dummy32->regs.fp_regs;
554 		*(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
555 
556 	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
557 		/*
558 		 * per_info is found in the thread structure.
559 		 */
560 		offset = addr - (addr_t) &dummy32->regs.per_info;
561 		/*
562 		 * This is magic. See per_struct and per_struct32.
563 		 * By incident the offsets in per_struct are exactly
564 		 * twice the offsets in per_struct32 for all fields.
565 		 * The 8 byte fields need special handling though,
566 		 * because the second half (bytes 4-7) is needed and
567 		 * not the first half.
568 		 */
569 		if ((offset >= (addr_t) &dummy_per32->control_regs &&
570 		     offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
571 		    (offset >= (addr_t) &dummy_per32->starting_addr &&
572 		     offset <= (addr_t) &dummy_per32->ending_addr) ||
573 		    offset == (addr_t) &dummy_per32->lowcore.words.address)
574 			offset = offset*2 + 4;
575 		else
576 			offset = offset*2;
577 		*(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;
578 
579 	}
580 
581 	FixPerRegisters(child);
582 	return 0;
583 }
584 
585 static int poke_user_compat(struct task_struct *child,
586 			    addr_t addr, addr_t data)
587 {
588 	if (!test_thread_flag(TIF_31BIT) ||
589 	    (addr & 3) || addr > sizeof(struct user32) - 3)
590 		return -EIO;
591 
592 	return __poke_user_compat(child, addr, data);
593 }
594 
595 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
596 			compat_ulong_t caddr, compat_ulong_t cdata)
597 {
598 	unsigned long addr = caddr;
599 	unsigned long data = cdata;
600 	ptrace_area_emu31 parea;
601 	int copied, ret;
602 
603 	switch (request) {
604 	case PTRACE_PEEKUSR:
605 		/* read the word at location addr in the USER area. */
606 		return peek_user_compat(child, addr, data);
607 
608 	case PTRACE_POKEUSR:
609 		/* write the word at location addr in the USER area */
610 		return poke_user_compat(child, addr, data);
611 
612 	case PTRACE_PEEKUSR_AREA:
613 	case PTRACE_POKEUSR_AREA:
614 		if (copy_from_user(&parea, (void __force __user *) addr,
615 							sizeof(parea)))
616 			return -EFAULT;
617 		addr = parea.kernel_addr;
618 		data = parea.process_addr;
619 		copied = 0;
620 		while (copied < parea.len) {
621 			if (request == PTRACE_PEEKUSR_AREA)
622 				ret = peek_user_compat(child, addr, data);
623 			else {
624 				__u32 utmp;
625 				if (get_user(utmp,
626 					     (__u32 __force __user *) data))
627 					return -EFAULT;
628 				ret = poke_user_compat(child, addr, utmp);
629 			}
630 			if (ret)
631 				return ret;
632 			addr += sizeof(unsigned int);
633 			data += sizeof(unsigned int);
634 			copied += sizeof(unsigned int);
635 		}
636 		return 0;
637 	}
638 	return compat_ptrace_request(child, request, addr, data);
639 }
640 #endif
641 
642 asmlinkage void
643 syscall_trace(struct pt_regs *regs, int entryexit)
644 {
645 	if (unlikely(current->audit_context) && entryexit)
646 		audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]), regs->gprs[2]);
647 
648 	if (!test_thread_flag(TIF_SYSCALL_TRACE))
649 		goto out;
650 	if (!(current->ptrace & PT_PTRACED))
651 		goto out;
652 	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
653 				 ? 0x80 : 0));
654 
655 	/*
656 	 * If the debuffer has set an invalid system call number,
657 	 * we prepare to skip the system call restart handling.
658 	 */
659 	if (!entryexit && regs->gprs[2] >= NR_syscalls)
660 		regs->trap = -1;
661 
662 	/*
663 	 * this isn't the same as continuing with a signal, but it will do
664 	 * for normal use.  strace only continues with a signal if the
665 	 * stopping signal is not SIGTRAP.  -brl
666 	 */
667 	if (current->exit_code) {
668 		send_sig(current->exit_code, current, 1);
669 		current->exit_code = 0;
670 	}
671  out:
672 	if (unlikely(current->audit_context) && !entryexit)
673 		audit_syscall_entry(test_thread_flag(TIF_31BIT)?AUDIT_ARCH_S390:AUDIT_ARCH_S390X,
674 				    regs->gprs[2], regs->orig_gpr2, regs->gprs[3],
675 				    regs->gprs[4], regs->gprs[5]);
676 }
677 
678 /*
679  * user_regset definitions.
680  */
681 
682 static int s390_regs_get(struct task_struct *target,
683 			 const struct user_regset *regset,
684 			 unsigned int pos, unsigned int count,
685 			 void *kbuf, void __user *ubuf)
686 {
687 	if (target == current)
688 		save_access_regs(target->thread.acrs);
689 
690 	if (kbuf) {
691 		unsigned long *k = kbuf;
692 		while (count > 0) {
693 			*k++ = __peek_user(target, pos);
694 			count -= sizeof(*k);
695 			pos += sizeof(*k);
696 		}
697 	} else {
698 		unsigned long __user *u = ubuf;
699 		while (count > 0) {
700 			if (__put_user(__peek_user(target, pos), u++))
701 				return -EFAULT;
702 			count -= sizeof(*u);
703 			pos += sizeof(*u);
704 		}
705 	}
706 	return 0;
707 }
708 
709 static int s390_regs_set(struct task_struct *target,
710 			 const struct user_regset *regset,
711 			 unsigned int pos, unsigned int count,
712 			 const void *kbuf, const void __user *ubuf)
713 {
714 	int rc = 0;
715 
716 	if (target == current)
717 		save_access_regs(target->thread.acrs);
718 
719 	if (kbuf) {
720 		const unsigned long *k = kbuf;
721 		while (count > 0 && !rc) {
722 			rc = __poke_user(target, pos, *k++);
723 			count -= sizeof(*k);
724 			pos += sizeof(*k);
725 		}
726 	} else {
727 		const unsigned long  __user *u = ubuf;
728 		while (count > 0 && !rc) {
729 			unsigned long word;
730 			rc = __get_user(word, u++);
731 			if (rc)
732 				break;
733 			rc = __poke_user(target, pos, word);
734 			count -= sizeof(*u);
735 			pos += sizeof(*u);
736 		}
737 	}
738 
739 	if (rc == 0 && target == current)
740 		restore_access_regs(target->thread.acrs);
741 
742 	return rc;
743 }
744 
745 static int s390_fpregs_get(struct task_struct *target,
746 			   const struct user_regset *regset, unsigned int pos,
747 			   unsigned int count, void *kbuf, void __user *ubuf)
748 {
749 	if (target == current)
750 		save_fp_regs(&target->thread.fp_regs);
751 
752 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
753 				   &target->thread.fp_regs, 0, -1);
754 }
755 
756 static int s390_fpregs_set(struct task_struct *target,
757 			   const struct user_regset *regset, unsigned int pos,
758 			   unsigned int count, const void *kbuf,
759 			   const void __user *ubuf)
760 {
761 	int rc = 0;
762 
763 	if (target == current)
764 		save_fp_regs(&target->thread.fp_regs);
765 
766 	/* If setting FPC, must validate it first. */
767 	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
768 		u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
769 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
770 					0, offsetof(s390_fp_regs, fprs));
771 		if (rc)
772 			return rc;
773 		if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
774 			return -EINVAL;
775 		target->thread.fp_regs.fpc = fpc[0];
776 	}
777 
778 	if (rc == 0 && count > 0)
779 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
780 					target->thread.fp_regs.fprs,
781 					offsetof(s390_fp_regs, fprs), -1);
782 
783 	if (rc == 0 && target == current)
784 		restore_fp_regs(&target->thread.fp_regs);
785 
786 	return rc;
787 }
788 
789 static const struct user_regset s390_regsets[] = {
790 	[REGSET_GENERAL] = {
791 		.core_note_type = NT_PRSTATUS,
792 		.n = sizeof(s390_regs) / sizeof(long),
793 		.size = sizeof(long),
794 		.align = sizeof(long),
795 		.get = s390_regs_get,
796 		.set = s390_regs_set,
797 	},
798 	[REGSET_FP] = {
799 		.core_note_type = NT_PRFPREG,
800 		.n = sizeof(s390_fp_regs) / sizeof(long),
801 		.size = sizeof(long),
802 		.align = sizeof(long),
803 		.get = s390_fpregs_get,
804 		.set = s390_fpregs_set,
805 	},
806 };
807 
808 static const struct user_regset_view user_s390_view = {
809 	.name = UTS_MACHINE,
810 	.e_machine = EM_S390,
811 	.regsets = s390_regsets,
812 	.n = ARRAY_SIZE(s390_regsets)
813 };
814 
815 #ifdef CONFIG_COMPAT
816 static int s390_compat_regs_get(struct task_struct *target,
817 				const struct user_regset *regset,
818 				unsigned int pos, unsigned int count,
819 				void *kbuf, void __user *ubuf)
820 {
821 	if (target == current)
822 		save_access_regs(target->thread.acrs);
823 
824 	if (kbuf) {
825 		compat_ulong_t *k = kbuf;
826 		while (count > 0) {
827 			*k++ = __peek_user_compat(target, pos);
828 			count -= sizeof(*k);
829 			pos += sizeof(*k);
830 		}
831 	} else {
832 		compat_ulong_t __user *u = ubuf;
833 		while (count > 0) {
834 			if (__put_user(__peek_user_compat(target, pos), u++))
835 				return -EFAULT;
836 			count -= sizeof(*u);
837 			pos += sizeof(*u);
838 		}
839 	}
840 	return 0;
841 }
842 
843 static int s390_compat_regs_set(struct task_struct *target,
844 				const struct user_regset *regset,
845 				unsigned int pos, unsigned int count,
846 				const void *kbuf, const void __user *ubuf)
847 {
848 	int rc = 0;
849 
850 	if (target == current)
851 		save_access_regs(target->thread.acrs);
852 
853 	if (kbuf) {
854 		const compat_ulong_t *k = kbuf;
855 		while (count > 0 && !rc) {
856 			rc = __poke_user_compat(target, pos, *k++);
857 			count -= sizeof(*k);
858 			pos += sizeof(*k);
859 		}
860 	} else {
861 		const compat_ulong_t  __user *u = ubuf;
862 		while (count > 0 && !rc) {
863 			compat_ulong_t word;
864 			rc = __get_user(word, u++);
865 			if (rc)
866 				break;
867 			rc = __poke_user_compat(target, pos, word);
868 			count -= sizeof(*u);
869 			pos += sizeof(*u);
870 		}
871 	}
872 
873 	if (rc == 0 && target == current)
874 		restore_access_regs(target->thread.acrs);
875 
876 	return rc;
877 }
878 
879 static const struct user_regset s390_compat_regsets[] = {
880 	[REGSET_GENERAL] = {
881 		.core_note_type = NT_PRSTATUS,
882 		.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
883 		.size = sizeof(compat_long_t),
884 		.align = sizeof(compat_long_t),
885 		.get = s390_compat_regs_get,
886 		.set = s390_compat_regs_set,
887 	},
888 	[REGSET_FP] = {
889 		.core_note_type = NT_PRFPREG,
890 		.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
891 		.size = sizeof(compat_long_t),
892 		.align = sizeof(compat_long_t),
893 		.get = s390_fpregs_get,
894 		.set = s390_fpregs_set,
895 	},
896 };
897 
898 static const struct user_regset_view user_s390_compat_view = {
899 	.name = "s390",
900 	.e_machine = EM_S390,
901 	.regsets = s390_compat_regsets,
902 	.n = ARRAY_SIZE(s390_compat_regsets)
903 };
904 #endif
905 
906 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
907 {
908 #ifdef CONFIG_COMPAT
909 	if (test_tsk_thread_flag(task, TIF_31BIT))
910 		return &user_s390_compat_view;
911 #endif
912 	return &user_s390_view;
913 }
914