xref: /openbmc/linux/arch/s390/kernel/ptrace.c (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
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 #include <linux/tracehook.h>
39 
40 #include <asm/segment.h>
41 #include <asm/page.h>
42 #include <asm/pgtable.h>
43 #include <asm/pgalloc.h>
44 #include <asm/system.h>
45 #include <asm/uaccess.h>
46 #include <asm/unistd.h>
47 #include "entry.h"
48 
49 #ifdef CONFIG_COMPAT
50 #include "compat_ptrace.h"
51 #endif
52 
53 enum s390_regset {
54 	REGSET_GENERAL,
55 	REGSET_FP,
56 };
57 
58 static void
59 FixPerRegisters(struct task_struct *task)
60 {
61 	struct pt_regs *regs;
62 	per_struct *per_info;
63 
64 	regs = task_pt_regs(task);
65 	per_info = (per_struct *) &task->thread.per_info;
66 	per_info->control_regs.bits.em_instruction_fetch =
67 		per_info->single_step | per_info->instruction_fetch;
68 
69 	if (per_info->single_step) {
70 		per_info->control_regs.bits.starting_addr = 0;
71 #ifdef CONFIG_COMPAT
72 		if (test_thread_flag(TIF_31BIT))
73 			per_info->control_regs.bits.ending_addr = 0x7fffffffUL;
74 		else
75 #endif
76 			per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN;
77 	} else {
78 		per_info->control_regs.bits.starting_addr =
79 			per_info->starting_addr;
80 		per_info->control_regs.bits.ending_addr =
81 			per_info->ending_addr;
82 	}
83 	/*
84 	 * if any of the control reg tracing bits are on
85 	 * we switch on per in the psw
86 	 */
87 	if (per_info->control_regs.words.cr[0] & PER_EM_MASK)
88 		regs->psw.mask |= PSW_MASK_PER;
89 	else
90 		regs->psw.mask &= ~PSW_MASK_PER;
91 
92 	if (per_info->control_regs.bits.em_storage_alteration)
93 		per_info->control_regs.bits.storage_alt_space_ctl = 1;
94 	else
95 		per_info->control_regs.bits.storage_alt_space_ctl = 0;
96 }
97 
98 void user_enable_single_step(struct task_struct *task)
99 {
100 	task->thread.per_info.single_step = 1;
101 	FixPerRegisters(task);
102 }
103 
104 void user_disable_single_step(struct task_struct *task)
105 {
106 	task->thread.per_info.single_step = 0;
107 	FixPerRegisters(task);
108 }
109 
110 /*
111  * Called by kernel/ptrace.c when detaching..
112  *
113  * Make sure single step bits etc are not set.
114  */
115 void
116 ptrace_disable(struct task_struct *child)
117 {
118 	/* make sure the single step bit is not set. */
119 	user_disable_single_step(child);
120 }
121 
122 #ifndef CONFIG_64BIT
123 # define __ADDR_MASK 3
124 #else
125 # define __ADDR_MASK 7
126 #endif
127 
128 /*
129  * Read the word at offset addr from the user area of a process. The
130  * trouble here is that the information is littered over different
131  * locations. The process registers are found on the kernel stack,
132  * the floating point stuff and the trace settings are stored in
133  * the task structure. In addition the different structures in
134  * struct user contain pad bytes that should be read as zeroes.
135  * Lovely...
136  */
137 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
138 {
139 	struct user *dummy = NULL;
140 	addr_t offset, tmp;
141 
142 	if (addr < (addr_t) &dummy->regs.acrs) {
143 		/*
144 		 * psw and gprs are stored on the stack
145 		 */
146 		tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
147 		if (addr == (addr_t) &dummy->regs.psw.mask)
148 			/* Remove per bit from user psw. */
149 			tmp &= ~PSW_MASK_PER;
150 
151 	} else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
152 		/*
153 		 * access registers are stored in the thread structure
154 		 */
155 		offset = addr - (addr_t) &dummy->regs.acrs;
156 #ifdef CONFIG_64BIT
157 		/*
158 		 * Very special case: old & broken 64 bit gdb reading
159 		 * from acrs[15]. Result is a 64 bit value. Read the
160 		 * 32 bit acrs[15] value and shift it by 32. Sick...
161 		 */
162 		if (addr == (addr_t) &dummy->regs.acrs[15])
163 			tmp = ((unsigned long) child->thread.acrs[15]) << 32;
164 		else
165 #endif
166 		tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
167 
168 	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
169 		/*
170 		 * orig_gpr2 is stored on the kernel stack
171 		 */
172 		tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
173 
174 	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
175 		/*
176 		 * prevent reads of padding hole between
177 		 * orig_gpr2 and fp_regs on s390.
178 		 */
179 		tmp = 0;
180 
181 	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
182 		/*
183 		 * floating point regs. are stored in the thread structure
184 		 */
185 		offset = addr - (addr_t) &dummy->regs.fp_regs;
186 		tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
187 		if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
188 			tmp &= (unsigned long) FPC_VALID_MASK
189 				<< (BITS_PER_LONG - 32);
190 
191 	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
192 		/*
193 		 * per_info is found in the thread structure
194 		 */
195 		offset = addr - (addr_t) &dummy->regs.per_info;
196 		tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset);
197 
198 	} else
199 		tmp = 0;
200 
201 	return tmp;
202 }
203 
204 static int
205 peek_user(struct task_struct *child, addr_t addr, addr_t data)
206 {
207 	struct user *dummy = NULL;
208 	addr_t tmp, mask;
209 
210 	/*
211 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
212 	 * an alignment of 4. Programmers from hell...
213 	 */
214 	mask = __ADDR_MASK;
215 #ifdef CONFIG_64BIT
216 	if (addr >= (addr_t) &dummy->regs.acrs &&
217 	    addr < (addr_t) &dummy->regs.orig_gpr2)
218 		mask = 3;
219 #endif
220 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
221 		return -EIO;
222 
223 	tmp = __peek_user(child, addr);
224 	return put_user(tmp, (addr_t __user *) data);
225 }
226 
227 /*
228  * Write a word to the user area of a process at location addr. This
229  * operation does have an additional problem compared to peek_user.
230  * Stores to the program status word and on the floating point
231  * control register needs to get checked for validity.
232  */
233 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
234 {
235 	struct user *dummy = NULL;
236 	addr_t offset;
237 
238 	if (addr < (addr_t) &dummy->regs.acrs) {
239 		/*
240 		 * psw and gprs are stored on the stack
241 		 */
242 		if (addr == (addr_t) &dummy->regs.psw.mask &&
243 #ifdef CONFIG_COMPAT
244 		    data != PSW_MASK_MERGE(psw_user32_bits, data) &&
245 #endif
246 		    data != PSW_MASK_MERGE(psw_user_bits, data))
247 			/* Invalid psw mask. */
248 			return -EINVAL;
249 #ifndef CONFIG_64BIT
250 		if (addr == (addr_t) &dummy->regs.psw.addr)
251 			/* I'd like to reject addresses without the
252 			   high order bit but older gdb's rely on it */
253 			data |= PSW_ADDR_AMODE;
254 #endif
255 		*(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
256 
257 	} else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
258 		/*
259 		 * access registers are stored in the thread structure
260 		 */
261 		offset = addr - (addr_t) &dummy->regs.acrs;
262 #ifdef CONFIG_64BIT
263 		/*
264 		 * Very special case: old & broken 64 bit gdb writing
265 		 * to acrs[15] with a 64 bit value. Ignore the lower
266 		 * half of the value and write the upper 32 bit to
267 		 * acrs[15]. Sick...
268 		 */
269 		if (addr == (addr_t) &dummy->regs.acrs[15])
270 			child->thread.acrs[15] = (unsigned int) (data >> 32);
271 		else
272 #endif
273 		*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
274 
275 	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
276 		/*
277 		 * orig_gpr2 is stored on the kernel stack
278 		 */
279 		task_pt_regs(child)->orig_gpr2 = data;
280 
281 	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
282 		/*
283 		 * prevent writes of padding hole between
284 		 * orig_gpr2 and fp_regs on s390.
285 		 */
286 		return 0;
287 
288 	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
289 		/*
290 		 * floating point regs. are stored in the thread structure
291 		 */
292 		if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
293 		    (data & ~((unsigned long) FPC_VALID_MASK
294 			      << (BITS_PER_LONG - 32))) != 0)
295 			return -EINVAL;
296 		offset = addr - (addr_t) &dummy->regs.fp_regs;
297 		*(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
298 
299 	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
300 		/*
301 		 * per_info is found in the thread structure
302 		 */
303 		offset = addr - (addr_t) &dummy->regs.per_info;
304 		*(addr_t *)((addr_t) &child->thread.per_info + offset) = data;
305 
306 	}
307 
308 	FixPerRegisters(child);
309 	return 0;
310 }
311 
312 static int
313 poke_user(struct task_struct *child, addr_t addr, addr_t data)
314 {
315 	struct user *dummy = NULL;
316 	addr_t mask;
317 
318 	/*
319 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
320 	 * an alignment of 4. Programmers from hell indeed...
321 	 */
322 	mask = __ADDR_MASK;
323 #ifdef CONFIG_64BIT
324 	if (addr >= (addr_t) &dummy->regs.acrs &&
325 	    addr < (addr_t) &dummy->regs.orig_gpr2)
326 		mask = 3;
327 #endif
328 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
329 		return -EIO;
330 
331 	return __poke_user(child, addr, data);
332 }
333 
334 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
335 {
336 	ptrace_area parea;
337 	int copied, ret;
338 
339 	switch (request) {
340 	case PTRACE_PEEKTEXT:
341 	case PTRACE_PEEKDATA:
342 		/* Remove high order bit from address (only for 31 bit). */
343 		addr &= PSW_ADDR_INSN;
344 		/* read word at location addr. */
345 		return generic_ptrace_peekdata(child, addr, data);
346 
347 	case PTRACE_PEEKUSR:
348 		/* read the word at location addr in the USER area. */
349 		return peek_user(child, addr, data);
350 
351 	case PTRACE_POKETEXT:
352 	case PTRACE_POKEDATA:
353 		/* Remove high order bit from address (only for 31 bit). */
354 		addr &= PSW_ADDR_INSN;
355 		/* write the word at location addr. */
356 		return generic_ptrace_pokedata(child, addr, data);
357 
358 	case PTRACE_POKEUSR:
359 		/* write the word at location addr in the USER area */
360 		return poke_user(child, addr, data);
361 
362 	case PTRACE_PEEKUSR_AREA:
363 	case PTRACE_POKEUSR_AREA:
364 		if (copy_from_user(&parea, (void __force __user *) addr,
365 							sizeof(parea)))
366 			return -EFAULT;
367 		addr = parea.kernel_addr;
368 		data = parea.process_addr;
369 		copied = 0;
370 		while (copied < parea.len) {
371 			if (request == PTRACE_PEEKUSR_AREA)
372 				ret = peek_user(child, addr, data);
373 			else {
374 				addr_t utmp;
375 				if (get_user(utmp,
376 					     (addr_t __force __user *) data))
377 					return -EFAULT;
378 				ret = poke_user(child, addr, utmp);
379 			}
380 			if (ret)
381 				return ret;
382 			addr += sizeof(unsigned long);
383 			data += sizeof(unsigned long);
384 			copied += sizeof(unsigned long);
385 		}
386 		return 0;
387 	}
388 	return ptrace_request(child, request, addr, data);
389 }
390 
391 #ifdef CONFIG_COMPAT
392 /*
393  * Now the fun part starts... a 31 bit program running in the
394  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
395  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
396  * to handle, the difference to the 64 bit versions of the requests
397  * is that the access is done in multiples of 4 byte instead of
398  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
399  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
400  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
401  * is a 31 bit program too, the content of struct user can be
402  * emulated. A 31 bit program peeking into the struct user of
403  * a 64 bit program is a no-no.
404  */
405 
406 /*
407  * Same as peek_user but for a 31 bit program.
408  */
409 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
410 {
411 	struct user32 *dummy32 = NULL;
412 	per_struct32 *dummy_per32 = NULL;
413 	addr_t offset;
414 	__u32 tmp;
415 
416 	if (addr < (addr_t) &dummy32->regs.acrs) {
417 		/*
418 		 * psw and gprs are stored on the stack
419 		 */
420 		if (addr == (addr_t) &dummy32->regs.psw.mask) {
421 			/* Fake a 31 bit psw mask. */
422 			tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
423 			tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
424 		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
425 			/* Fake a 31 bit psw address. */
426 			tmp = (__u32) task_pt_regs(child)->psw.addr |
427 				PSW32_ADDR_AMODE31;
428 		} else {
429 			/* gpr 0-15 */
430 			tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
431 					 addr*2 + 4);
432 		}
433 	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
434 		/*
435 		 * access registers are stored in the thread structure
436 		 */
437 		offset = addr - (addr_t) &dummy32->regs.acrs;
438 		tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
439 
440 	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
441 		/*
442 		 * orig_gpr2 is stored on the kernel stack
443 		 */
444 		tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
445 
446 	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
447 		/*
448 		 * prevent reads of padding hole between
449 		 * orig_gpr2 and fp_regs on s390.
450 		 */
451 		tmp = 0;
452 
453 	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
454 		/*
455 		 * floating point regs. are stored in the thread structure
456 		 */
457 	        offset = addr - (addr_t) &dummy32->regs.fp_regs;
458 		tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
459 
460 	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
461 		/*
462 		 * per_info is found in the thread structure
463 		 */
464 		offset = addr - (addr_t) &dummy32->regs.per_info;
465 		/* This is magic. See per_struct and per_struct32. */
466 		if ((offset >= (addr_t) &dummy_per32->control_regs &&
467 		     offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
468 		    (offset >= (addr_t) &dummy_per32->starting_addr &&
469 		     offset <= (addr_t) &dummy_per32->ending_addr) ||
470 		    offset == (addr_t) &dummy_per32->lowcore.words.address)
471 			offset = offset*2 + 4;
472 		else
473 			offset = offset*2;
474 		tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);
475 
476 	} else
477 		tmp = 0;
478 
479 	return tmp;
480 }
481 
482 static int peek_user_compat(struct task_struct *child,
483 			    addr_t addr, addr_t data)
484 {
485 	__u32 tmp;
486 
487 	if (!test_thread_flag(TIF_31BIT) ||
488 	    (addr & 3) || addr > sizeof(struct user) - 3)
489 		return -EIO;
490 
491 	tmp = __peek_user_compat(child, addr);
492 	return put_user(tmp, (__u32 __user *) data);
493 }
494 
495 /*
496  * Same as poke_user but for a 31 bit program.
497  */
498 static int __poke_user_compat(struct task_struct *child,
499 			      addr_t addr, addr_t data)
500 {
501 	struct user32 *dummy32 = NULL;
502 	per_struct32 *dummy_per32 = NULL;
503 	__u32 tmp = (__u32) data;
504 	addr_t offset;
505 
506 	if (addr < (addr_t) &dummy32->regs.acrs) {
507 		/*
508 		 * psw, gprs, acrs and orig_gpr2 are stored on the stack
509 		 */
510 		if (addr == (addr_t) &dummy32->regs.psw.mask) {
511 			/* Build a 64 bit psw mask from 31 bit mask. */
512 			if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
513 				/* Invalid psw mask. */
514 				return -EINVAL;
515 			task_pt_regs(child)->psw.mask =
516 				PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
517 		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
518 			/* Build a 64 bit psw address from 31 bit address. */
519 			task_pt_regs(child)->psw.addr =
520 				(__u64) tmp & PSW32_ADDR_INSN;
521 		} else {
522 			/* gpr 0-15 */
523 			*(__u32*)((addr_t) &task_pt_regs(child)->psw
524 				  + addr*2 + 4) = tmp;
525 		}
526 	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
527 		/*
528 		 * access registers are stored in the thread structure
529 		 */
530 		offset = addr - (addr_t) &dummy32->regs.acrs;
531 		*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
532 
533 	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
534 		/*
535 		 * orig_gpr2 is stored on the kernel stack
536 		 */
537 		*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
538 
539 	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
540 		/*
541 		 * prevent writess of padding hole between
542 		 * orig_gpr2 and fp_regs on s390.
543 		 */
544 		return 0;
545 
546 	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
547 		/*
548 		 * floating point regs. are stored in the thread structure
549 		 */
550 		if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
551 		    (tmp & ~FPC_VALID_MASK) != 0)
552 			/* Invalid floating point control. */
553 			return -EINVAL;
554 	        offset = addr - (addr_t) &dummy32->regs.fp_regs;
555 		*(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
556 
557 	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
558 		/*
559 		 * per_info is found in the thread structure.
560 		 */
561 		offset = addr - (addr_t) &dummy32->regs.per_info;
562 		/*
563 		 * This is magic. See per_struct and per_struct32.
564 		 * By incident the offsets in per_struct are exactly
565 		 * twice the offsets in per_struct32 for all fields.
566 		 * The 8 byte fields need special handling though,
567 		 * because the second half (bytes 4-7) is needed and
568 		 * not the first half.
569 		 */
570 		if ((offset >= (addr_t) &dummy_per32->control_regs &&
571 		     offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
572 		    (offset >= (addr_t) &dummy_per32->starting_addr &&
573 		     offset <= (addr_t) &dummy_per32->ending_addr) ||
574 		    offset == (addr_t) &dummy_per32->lowcore.words.address)
575 			offset = offset*2 + 4;
576 		else
577 			offset = offset*2;
578 		*(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;
579 
580 	}
581 
582 	FixPerRegisters(child);
583 	return 0;
584 }
585 
586 static int poke_user_compat(struct task_struct *child,
587 			    addr_t addr, addr_t data)
588 {
589 	if (!test_thread_flag(TIF_31BIT) ||
590 	    (addr & 3) || addr > sizeof(struct user32) - 3)
591 		return -EIO;
592 
593 	return __poke_user_compat(child, addr, data);
594 }
595 
596 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
597 			compat_ulong_t caddr, compat_ulong_t cdata)
598 {
599 	unsigned long addr = caddr;
600 	unsigned long data = cdata;
601 	ptrace_area_emu31 parea;
602 	int copied, ret;
603 
604 	switch (request) {
605 	case PTRACE_PEEKUSR:
606 		/* read the word at location addr in the USER area. */
607 		return peek_user_compat(child, addr, data);
608 
609 	case PTRACE_POKEUSR:
610 		/* write the word at location addr in the USER area */
611 		return poke_user_compat(child, addr, data);
612 
613 	case PTRACE_PEEKUSR_AREA:
614 	case PTRACE_POKEUSR_AREA:
615 		if (copy_from_user(&parea, (void __force __user *) addr,
616 							sizeof(parea)))
617 			return -EFAULT;
618 		addr = parea.kernel_addr;
619 		data = parea.process_addr;
620 		copied = 0;
621 		while (copied < parea.len) {
622 			if (request == PTRACE_PEEKUSR_AREA)
623 				ret = peek_user_compat(child, addr, data);
624 			else {
625 				__u32 utmp;
626 				if (get_user(utmp,
627 					     (__u32 __force __user *) data))
628 					return -EFAULT;
629 				ret = poke_user_compat(child, addr, utmp);
630 			}
631 			if (ret)
632 				return ret;
633 			addr += sizeof(unsigned int);
634 			data += sizeof(unsigned int);
635 			copied += sizeof(unsigned int);
636 		}
637 		return 0;
638 	}
639 	return compat_ptrace_request(child, request, addr, data);
640 }
641 #endif
642 
643 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
644 {
645 	long ret;
646 
647 	/*
648 	 * The sysc_tracesys code in entry.S stored the system
649 	 * call number to gprs[2].
650 	 */
651 	ret = regs->gprs[2];
652 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
653 	    (tracehook_report_syscall_entry(regs) ||
654 	     regs->gprs[2] >= NR_syscalls)) {
655 		/*
656 		 * Tracing decided this syscall should not happen or the
657 		 * debugger stored an invalid system call number. Skip
658 		 * the system call and the system call restart handling.
659 		 */
660 		regs->trap = -1;
661 		ret = -1;
662 	}
663 
664 	if (unlikely(current->audit_context))
665 		audit_syscall_entry(test_thread_flag(TIF_31BIT) ?
666 					AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
667 				    regs->gprs[2], regs->orig_gpr2,
668 				    regs->gprs[3], regs->gprs[4],
669 				    regs->gprs[5]);
670 	return ret;
671 }
672 
673 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
674 {
675 	if (unlikely(current->audit_context))
676 		audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
677 				   regs->gprs[2]);
678 
679 	if (test_thread_flag(TIF_SYSCALL_TRACE))
680 		tracehook_report_syscall_exit(regs, 0);
681 }
682 
683 /*
684  * user_regset definitions.
685  */
686 
687 static int s390_regs_get(struct task_struct *target,
688 			 const struct user_regset *regset,
689 			 unsigned int pos, unsigned int count,
690 			 void *kbuf, void __user *ubuf)
691 {
692 	if (target == current)
693 		save_access_regs(target->thread.acrs);
694 
695 	if (kbuf) {
696 		unsigned long *k = kbuf;
697 		while (count > 0) {
698 			*k++ = __peek_user(target, pos);
699 			count -= sizeof(*k);
700 			pos += sizeof(*k);
701 		}
702 	} else {
703 		unsigned long __user *u = ubuf;
704 		while (count > 0) {
705 			if (__put_user(__peek_user(target, pos), u++))
706 				return -EFAULT;
707 			count -= sizeof(*u);
708 			pos += sizeof(*u);
709 		}
710 	}
711 	return 0;
712 }
713 
714 static int s390_regs_set(struct task_struct *target,
715 			 const struct user_regset *regset,
716 			 unsigned int pos, unsigned int count,
717 			 const void *kbuf, const void __user *ubuf)
718 {
719 	int rc = 0;
720 
721 	if (target == current)
722 		save_access_regs(target->thread.acrs);
723 
724 	if (kbuf) {
725 		const unsigned long *k = kbuf;
726 		while (count > 0 && !rc) {
727 			rc = __poke_user(target, pos, *k++);
728 			count -= sizeof(*k);
729 			pos += sizeof(*k);
730 		}
731 	} else {
732 		const unsigned long  __user *u = ubuf;
733 		while (count > 0 && !rc) {
734 			unsigned long word;
735 			rc = __get_user(word, u++);
736 			if (rc)
737 				break;
738 			rc = __poke_user(target, pos, word);
739 			count -= sizeof(*u);
740 			pos += sizeof(*u);
741 		}
742 	}
743 
744 	if (rc == 0 && target == current)
745 		restore_access_regs(target->thread.acrs);
746 
747 	return rc;
748 }
749 
750 static int s390_fpregs_get(struct task_struct *target,
751 			   const struct user_regset *regset, unsigned int pos,
752 			   unsigned int count, void *kbuf, void __user *ubuf)
753 {
754 	if (target == current)
755 		save_fp_regs(&target->thread.fp_regs);
756 
757 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
758 				   &target->thread.fp_regs, 0, -1);
759 }
760 
761 static int s390_fpregs_set(struct task_struct *target,
762 			   const struct user_regset *regset, unsigned int pos,
763 			   unsigned int count, const void *kbuf,
764 			   const void __user *ubuf)
765 {
766 	int rc = 0;
767 
768 	if (target == current)
769 		save_fp_regs(&target->thread.fp_regs);
770 
771 	/* If setting FPC, must validate it first. */
772 	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
773 		u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
774 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
775 					0, offsetof(s390_fp_regs, fprs));
776 		if (rc)
777 			return rc;
778 		if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
779 			return -EINVAL;
780 		target->thread.fp_regs.fpc = fpc[0];
781 	}
782 
783 	if (rc == 0 && count > 0)
784 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
785 					target->thread.fp_regs.fprs,
786 					offsetof(s390_fp_regs, fprs), -1);
787 
788 	if (rc == 0 && target == current)
789 		restore_fp_regs(&target->thread.fp_regs);
790 
791 	return rc;
792 }
793 
794 static const struct user_regset s390_regsets[] = {
795 	[REGSET_GENERAL] = {
796 		.core_note_type = NT_PRSTATUS,
797 		.n = sizeof(s390_regs) / sizeof(long),
798 		.size = sizeof(long),
799 		.align = sizeof(long),
800 		.get = s390_regs_get,
801 		.set = s390_regs_set,
802 	},
803 	[REGSET_FP] = {
804 		.core_note_type = NT_PRFPREG,
805 		.n = sizeof(s390_fp_regs) / sizeof(long),
806 		.size = sizeof(long),
807 		.align = sizeof(long),
808 		.get = s390_fpregs_get,
809 		.set = s390_fpregs_set,
810 	},
811 };
812 
813 static const struct user_regset_view user_s390_view = {
814 	.name = UTS_MACHINE,
815 	.e_machine = EM_S390,
816 	.regsets = s390_regsets,
817 	.n = ARRAY_SIZE(s390_regsets)
818 };
819 
820 #ifdef CONFIG_COMPAT
821 static int s390_compat_regs_get(struct task_struct *target,
822 				const struct user_regset *regset,
823 				unsigned int pos, unsigned int count,
824 				void *kbuf, void __user *ubuf)
825 {
826 	if (target == current)
827 		save_access_regs(target->thread.acrs);
828 
829 	if (kbuf) {
830 		compat_ulong_t *k = kbuf;
831 		while (count > 0) {
832 			*k++ = __peek_user_compat(target, pos);
833 			count -= sizeof(*k);
834 			pos += sizeof(*k);
835 		}
836 	} else {
837 		compat_ulong_t __user *u = ubuf;
838 		while (count > 0) {
839 			if (__put_user(__peek_user_compat(target, pos), u++))
840 				return -EFAULT;
841 			count -= sizeof(*u);
842 			pos += sizeof(*u);
843 		}
844 	}
845 	return 0;
846 }
847 
848 static int s390_compat_regs_set(struct task_struct *target,
849 				const struct user_regset *regset,
850 				unsigned int pos, unsigned int count,
851 				const void *kbuf, const void __user *ubuf)
852 {
853 	int rc = 0;
854 
855 	if (target == current)
856 		save_access_regs(target->thread.acrs);
857 
858 	if (kbuf) {
859 		const compat_ulong_t *k = kbuf;
860 		while (count > 0 && !rc) {
861 			rc = __poke_user_compat(target, pos, *k++);
862 			count -= sizeof(*k);
863 			pos += sizeof(*k);
864 		}
865 	} else {
866 		const compat_ulong_t  __user *u = ubuf;
867 		while (count > 0 && !rc) {
868 			compat_ulong_t word;
869 			rc = __get_user(word, u++);
870 			if (rc)
871 				break;
872 			rc = __poke_user_compat(target, pos, word);
873 			count -= sizeof(*u);
874 			pos += sizeof(*u);
875 		}
876 	}
877 
878 	if (rc == 0 && target == current)
879 		restore_access_regs(target->thread.acrs);
880 
881 	return rc;
882 }
883 
884 static const struct user_regset s390_compat_regsets[] = {
885 	[REGSET_GENERAL] = {
886 		.core_note_type = NT_PRSTATUS,
887 		.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
888 		.size = sizeof(compat_long_t),
889 		.align = sizeof(compat_long_t),
890 		.get = s390_compat_regs_get,
891 		.set = s390_compat_regs_set,
892 	},
893 	[REGSET_FP] = {
894 		.core_note_type = NT_PRFPREG,
895 		.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
896 		.size = sizeof(compat_long_t),
897 		.align = sizeof(compat_long_t),
898 		.get = s390_fpregs_get,
899 		.set = s390_fpregs_set,
900 	},
901 };
902 
903 static const struct user_regset_view user_s390_compat_view = {
904 	.name = "s390",
905 	.e_machine = EM_S390,
906 	.regsets = s390_compat_regsets,
907 	.n = ARRAY_SIZE(s390_compat_regsets)
908 };
909 #endif
910 
911 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
912 {
913 #ifdef CONFIG_COMPAT
914 	if (test_tsk_thread_flag(task, TIF_31BIT))
915 		return &user_s390_compat_view;
916 #endif
917 	return &user_s390_view;
918 }
919