xref: /openbmc/linux/arch/s390/kernel/ptrace.c (revision ca55b2fe)
1 /*
2  *  Ptrace user space interface.
3  *
4  *    Copyright IBM Corp. 1999, 2010
5  *    Author(s): Denis Joseph Barrow
6  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
11 #include <linux/mm.h>
12 #include <linux/smp.h>
13 #include <linux/errno.h>
14 #include <linux/ptrace.h>
15 #include <linux/user.h>
16 #include <linux/security.h>
17 #include <linux/audit.h>
18 #include <linux/signal.h>
19 #include <linux/elf.h>
20 #include <linux/regset.h>
21 #include <linux/tracehook.h>
22 #include <linux/seccomp.h>
23 #include <linux/compat.h>
24 #include <trace/syscall.h>
25 #include <asm/segment.h>
26 #include <asm/page.h>
27 #include <asm/pgtable.h>
28 #include <asm/pgalloc.h>
29 #include <asm/uaccess.h>
30 #include <asm/unistd.h>
31 #include <asm/switch_to.h>
32 #include "entry.h"
33 
34 #ifdef CONFIG_COMPAT
35 #include "compat_ptrace.h"
36 #endif
37 
38 #define CREATE_TRACE_POINTS
39 #include <trace/events/syscalls.h>
40 
41 void update_cr_regs(struct task_struct *task)
42 {
43 	struct pt_regs *regs = task_pt_regs(task);
44 	struct thread_struct *thread = &task->thread;
45 	struct per_regs old, new;
46 
47 	/* Take care of the enable/disable of transactional execution. */
48 	if (MACHINE_HAS_TE) {
49 		unsigned long cr, cr_new;
50 
51 		__ctl_store(cr, 0, 0);
52 		/* Set or clear transaction execution TXC bit 8. */
53 		cr_new = cr | (1UL << 55);
54 		if (task->thread.per_flags & PER_FLAG_NO_TE)
55 			cr_new &= ~(1UL << 55);
56 		if (cr_new != cr)
57 			__ctl_load(cr_new, 0, 0);
58 		/* Set or clear transaction execution TDC bits 62 and 63. */
59 		__ctl_store(cr, 2, 2);
60 		cr_new = cr & ~3UL;
61 		if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
62 			if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
63 				cr_new |= 1UL;
64 			else
65 				cr_new |= 2UL;
66 		}
67 		if (cr_new != cr)
68 			__ctl_load(cr_new, 2, 2);
69 	}
70 	/* Copy user specified PER registers */
71 	new.control = thread->per_user.control;
72 	new.start = thread->per_user.start;
73 	new.end = thread->per_user.end;
74 
75 	/* merge TIF_SINGLE_STEP into user specified PER registers. */
76 	if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
77 	    test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
78 		if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
79 			new.control |= PER_EVENT_BRANCH;
80 		else
81 			new.control |= PER_EVENT_IFETCH;
82 		new.control |= PER_CONTROL_SUSPENSION;
83 		new.control |= PER_EVENT_TRANSACTION_END;
84 		if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
85 			new.control |= PER_EVENT_IFETCH;
86 		new.start = 0;
87 		new.end = PSW_ADDR_INSN;
88 	}
89 
90 	/* Take care of the PER enablement bit in the PSW. */
91 	if (!(new.control & PER_EVENT_MASK)) {
92 		regs->psw.mask &= ~PSW_MASK_PER;
93 		return;
94 	}
95 	regs->psw.mask |= PSW_MASK_PER;
96 	__ctl_store(old, 9, 11);
97 	if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
98 		__ctl_load(new, 9, 11);
99 }
100 
101 void user_enable_single_step(struct task_struct *task)
102 {
103 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
104 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
105 }
106 
107 void user_disable_single_step(struct task_struct *task)
108 {
109 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
110 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
111 }
112 
113 void user_enable_block_step(struct task_struct *task)
114 {
115 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
116 	set_tsk_thread_flag(task, TIF_BLOCK_STEP);
117 }
118 
119 /*
120  * Called by kernel/ptrace.c when detaching..
121  *
122  * Clear all debugging related fields.
123  */
124 void ptrace_disable(struct task_struct *task)
125 {
126 	memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
127 	memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
128 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
129 	clear_pt_regs_flag(task_pt_regs(task), PIF_PER_TRAP);
130 	task->thread.per_flags = 0;
131 }
132 
133 #define __ADDR_MASK 7
134 
135 static inline unsigned long __peek_user_per(struct task_struct *child,
136 					    addr_t addr)
137 {
138 	struct per_struct_kernel *dummy = NULL;
139 
140 	if (addr == (addr_t) &dummy->cr9)
141 		/* Control bits of the active per set. */
142 		return test_thread_flag(TIF_SINGLE_STEP) ?
143 			PER_EVENT_IFETCH : child->thread.per_user.control;
144 	else if (addr == (addr_t) &dummy->cr10)
145 		/* Start address of the active per set. */
146 		return test_thread_flag(TIF_SINGLE_STEP) ?
147 			0 : child->thread.per_user.start;
148 	else if (addr == (addr_t) &dummy->cr11)
149 		/* End address of the active per set. */
150 		return test_thread_flag(TIF_SINGLE_STEP) ?
151 			PSW_ADDR_INSN : child->thread.per_user.end;
152 	else if (addr == (addr_t) &dummy->bits)
153 		/* Single-step bit. */
154 		return test_thread_flag(TIF_SINGLE_STEP) ?
155 			(1UL << (BITS_PER_LONG - 1)) : 0;
156 	else if (addr == (addr_t) &dummy->starting_addr)
157 		/* Start address of the user specified per set. */
158 		return child->thread.per_user.start;
159 	else if (addr == (addr_t) &dummy->ending_addr)
160 		/* End address of the user specified per set. */
161 		return child->thread.per_user.end;
162 	else if (addr == (addr_t) &dummy->perc_atmid)
163 		/* PER code, ATMID and AI of the last PER trap */
164 		return (unsigned long)
165 			child->thread.per_event.cause << (BITS_PER_LONG - 16);
166 	else if (addr == (addr_t) &dummy->address)
167 		/* Address of the last PER trap */
168 		return child->thread.per_event.address;
169 	else if (addr == (addr_t) &dummy->access_id)
170 		/* Access id of the last PER trap */
171 		return (unsigned long)
172 			child->thread.per_event.paid << (BITS_PER_LONG - 8);
173 	return 0;
174 }
175 
176 /*
177  * Read the word at offset addr from the user area of a process. The
178  * trouble here is that the information is littered over different
179  * locations. The process registers are found on the kernel stack,
180  * the floating point stuff and the trace settings are stored in
181  * the task structure. In addition the different structures in
182  * struct user contain pad bytes that should be read as zeroes.
183  * Lovely...
184  */
185 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
186 {
187 	struct user *dummy = NULL;
188 	addr_t offset, tmp;
189 
190 	if (addr < (addr_t) &dummy->regs.acrs) {
191 		/*
192 		 * psw and gprs are stored on the stack
193 		 */
194 		tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
195 		if (addr == (addr_t) &dummy->regs.psw.mask) {
196 			/* Return a clean psw mask. */
197 			tmp &= PSW_MASK_USER | PSW_MASK_RI;
198 			tmp |= PSW_USER_BITS;
199 		}
200 
201 	} else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
202 		/*
203 		 * access registers are stored in the thread structure
204 		 */
205 		offset = addr - (addr_t) &dummy->regs.acrs;
206 		/*
207 		 * Very special case: old & broken 64 bit gdb reading
208 		 * from acrs[15]. Result is a 64 bit value. Read the
209 		 * 32 bit acrs[15] value and shift it by 32. Sick...
210 		 */
211 		if (addr == (addr_t) &dummy->regs.acrs[15])
212 			tmp = ((unsigned long) child->thread.acrs[15]) << 32;
213 		else
214 			tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
215 
216 	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
217 		/*
218 		 * orig_gpr2 is stored on the kernel stack
219 		 */
220 		tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
221 
222 	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
223 		/*
224 		 * prevent reads of padding hole between
225 		 * orig_gpr2 and fp_regs on s390.
226 		 */
227 		tmp = 0;
228 
229 	} else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
230 		/*
231 		 * floating point control reg. is in the thread structure
232 		 */
233 		tmp = child->thread.fpu.fpc;
234 		tmp <<= BITS_PER_LONG - 32;
235 
236 	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
237 		/*
238 		 * floating point regs. are either in child->thread.fpu
239 		 * or the child->thread.fpu.vxrs array
240 		 */
241 		offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
242 		if (is_vx_task(child))
243 			tmp = *(addr_t *)
244 			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
245 		else
246 			tmp = *(addr_t *)
247 			       ((addr_t) &child->thread.fpu.fprs + offset);
248 
249 	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
250 		/*
251 		 * Handle access to the per_info structure.
252 		 */
253 		addr -= (addr_t) &dummy->regs.per_info;
254 		tmp = __peek_user_per(child, addr);
255 
256 	} else
257 		tmp = 0;
258 
259 	return tmp;
260 }
261 
262 static int
263 peek_user(struct task_struct *child, addr_t addr, addr_t data)
264 {
265 	addr_t tmp, mask;
266 
267 	/*
268 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
269 	 * an alignment of 4. Programmers from hell...
270 	 */
271 	mask = __ADDR_MASK;
272 	if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
273 	    addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
274 		mask = 3;
275 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
276 		return -EIO;
277 
278 	tmp = __peek_user(child, addr);
279 	return put_user(tmp, (addr_t __user *) data);
280 }
281 
282 static inline void __poke_user_per(struct task_struct *child,
283 				   addr_t addr, addr_t data)
284 {
285 	struct per_struct_kernel *dummy = NULL;
286 
287 	/*
288 	 * There are only three fields in the per_info struct that the
289 	 * debugger user can write to.
290 	 * 1) cr9: the debugger wants to set a new PER event mask
291 	 * 2) starting_addr: the debugger wants to set a new starting
292 	 *    address to use with the PER event mask.
293 	 * 3) ending_addr: the debugger wants to set a new ending
294 	 *    address to use with the PER event mask.
295 	 * The user specified PER event mask and the start and end
296 	 * addresses are used only if single stepping is not in effect.
297 	 * Writes to any other field in per_info are ignored.
298 	 */
299 	if (addr == (addr_t) &dummy->cr9)
300 		/* PER event mask of the user specified per set. */
301 		child->thread.per_user.control =
302 			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
303 	else if (addr == (addr_t) &dummy->starting_addr)
304 		/* Starting address of the user specified per set. */
305 		child->thread.per_user.start = data;
306 	else if (addr == (addr_t) &dummy->ending_addr)
307 		/* Ending address of the user specified per set. */
308 		child->thread.per_user.end = data;
309 }
310 
311 /*
312  * Write a word to the user area of a process at location addr. This
313  * operation does have an additional problem compared to peek_user.
314  * Stores to the program status word and on the floating point
315  * control register needs to get checked for validity.
316  */
317 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
318 {
319 	struct user *dummy = NULL;
320 	addr_t offset;
321 
322 	if (addr < (addr_t) &dummy->regs.acrs) {
323 		/*
324 		 * psw and gprs are stored on the stack
325 		 */
326 		if (addr == (addr_t) &dummy->regs.psw.mask) {
327 			unsigned long mask = PSW_MASK_USER;
328 
329 			mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
330 			if ((data ^ PSW_USER_BITS) & ~mask)
331 				/* Invalid psw mask. */
332 				return -EINVAL;
333 			if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
334 				/* Invalid address-space-control bits */
335 				return -EINVAL;
336 			if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
337 				/* Invalid addressing mode bits */
338 				return -EINVAL;
339 		}
340 		*(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
341 
342 	} else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
343 		/*
344 		 * access registers are stored in the thread structure
345 		 */
346 		offset = addr - (addr_t) &dummy->regs.acrs;
347 		/*
348 		 * Very special case: old & broken 64 bit gdb writing
349 		 * to acrs[15] with a 64 bit value. Ignore the lower
350 		 * half of the value and write the upper 32 bit to
351 		 * acrs[15]. Sick...
352 		 */
353 		if (addr == (addr_t) &dummy->regs.acrs[15])
354 			child->thread.acrs[15] = (unsigned int) (data >> 32);
355 		else
356 			*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
357 
358 	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
359 		/*
360 		 * orig_gpr2 is stored on the kernel stack
361 		 */
362 		task_pt_regs(child)->orig_gpr2 = data;
363 
364 	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
365 		/*
366 		 * prevent writes of padding hole between
367 		 * orig_gpr2 and fp_regs on s390.
368 		 */
369 		return 0;
370 
371 	} else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
372 		/*
373 		 * floating point control reg. is in the thread structure
374 		 */
375 		if ((unsigned int) data != 0 ||
376 		    test_fp_ctl(data >> (BITS_PER_LONG - 32)))
377 			return -EINVAL;
378 		child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
379 
380 	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
381 		/*
382 		 * floating point regs. are either in child->thread.fpu
383 		 * or the child->thread.fpu.vxrs array
384 		 */
385 		offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
386 		if (is_vx_task(child))
387 			*(addr_t *)((addr_t)
388 				child->thread.fpu.vxrs + 2*offset) = data;
389 		else
390 			*(addr_t *)((addr_t)
391 				&child->thread.fpu.fprs + offset) = data;
392 
393 	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
394 		/*
395 		 * Handle access to the per_info structure.
396 		 */
397 		addr -= (addr_t) &dummy->regs.per_info;
398 		__poke_user_per(child, addr, data);
399 
400 	}
401 
402 	return 0;
403 }
404 
405 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
406 {
407 	addr_t mask;
408 
409 	/*
410 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
411 	 * an alignment of 4. Programmers from hell indeed...
412 	 */
413 	mask = __ADDR_MASK;
414 	if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
415 	    addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
416 		mask = 3;
417 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
418 		return -EIO;
419 
420 	return __poke_user(child, addr, data);
421 }
422 
423 long arch_ptrace(struct task_struct *child, long request,
424 		 unsigned long addr, unsigned long data)
425 {
426 	ptrace_area parea;
427 	int copied, ret;
428 
429 	switch (request) {
430 	case PTRACE_PEEKUSR:
431 		/* read the word at location addr in the USER area. */
432 		return peek_user(child, addr, data);
433 
434 	case PTRACE_POKEUSR:
435 		/* write the word at location addr in the USER area */
436 		return poke_user(child, addr, data);
437 
438 	case PTRACE_PEEKUSR_AREA:
439 	case PTRACE_POKEUSR_AREA:
440 		if (copy_from_user(&parea, (void __force __user *) addr,
441 							sizeof(parea)))
442 			return -EFAULT;
443 		addr = parea.kernel_addr;
444 		data = parea.process_addr;
445 		copied = 0;
446 		while (copied < parea.len) {
447 			if (request == PTRACE_PEEKUSR_AREA)
448 				ret = peek_user(child, addr, data);
449 			else {
450 				addr_t utmp;
451 				if (get_user(utmp,
452 					     (addr_t __force __user *) data))
453 					return -EFAULT;
454 				ret = poke_user(child, addr, utmp);
455 			}
456 			if (ret)
457 				return ret;
458 			addr += sizeof(unsigned long);
459 			data += sizeof(unsigned long);
460 			copied += sizeof(unsigned long);
461 		}
462 		return 0;
463 	case PTRACE_GET_LAST_BREAK:
464 		put_user(task_thread_info(child)->last_break,
465 			 (unsigned long __user *) data);
466 		return 0;
467 	case PTRACE_ENABLE_TE:
468 		if (!MACHINE_HAS_TE)
469 			return -EIO;
470 		child->thread.per_flags &= ~PER_FLAG_NO_TE;
471 		return 0;
472 	case PTRACE_DISABLE_TE:
473 		if (!MACHINE_HAS_TE)
474 			return -EIO;
475 		child->thread.per_flags |= PER_FLAG_NO_TE;
476 		child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
477 		return 0;
478 	case PTRACE_TE_ABORT_RAND:
479 		if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
480 			return -EIO;
481 		switch (data) {
482 		case 0UL:
483 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
484 			break;
485 		case 1UL:
486 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
487 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
488 			break;
489 		case 2UL:
490 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
491 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
492 			break;
493 		default:
494 			return -EINVAL;
495 		}
496 		return 0;
497 	default:
498 		/* Removing high order bit from addr (only for 31 bit). */
499 		addr &= PSW_ADDR_INSN;
500 		return ptrace_request(child, request, addr, data);
501 	}
502 }
503 
504 #ifdef CONFIG_COMPAT
505 /*
506  * Now the fun part starts... a 31 bit program running in the
507  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
508  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
509  * to handle, the difference to the 64 bit versions of the requests
510  * is that the access is done in multiples of 4 byte instead of
511  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
512  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
513  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
514  * is a 31 bit program too, the content of struct user can be
515  * emulated. A 31 bit program peeking into the struct user of
516  * a 64 bit program is a no-no.
517  */
518 
519 /*
520  * Same as peek_user_per but for a 31 bit program.
521  */
522 static inline __u32 __peek_user_per_compat(struct task_struct *child,
523 					   addr_t addr)
524 {
525 	struct compat_per_struct_kernel *dummy32 = NULL;
526 
527 	if (addr == (addr_t) &dummy32->cr9)
528 		/* Control bits of the active per set. */
529 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
530 			PER_EVENT_IFETCH : child->thread.per_user.control;
531 	else if (addr == (addr_t) &dummy32->cr10)
532 		/* Start address of the active per set. */
533 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
534 			0 : child->thread.per_user.start;
535 	else if (addr == (addr_t) &dummy32->cr11)
536 		/* End address of the active per set. */
537 		return test_thread_flag(TIF_SINGLE_STEP) ?
538 			PSW32_ADDR_INSN : child->thread.per_user.end;
539 	else if (addr == (addr_t) &dummy32->bits)
540 		/* Single-step bit. */
541 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
542 			0x80000000 : 0;
543 	else if (addr == (addr_t) &dummy32->starting_addr)
544 		/* Start address of the user specified per set. */
545 		return (__u32) child->thread.per_user.start;
546 	else if (addr == (addr_t) &dummy32->ending_addr)
547 		/* End address of the user specified per set. */
548 		return (__u32) child->thread.per_user.end;
549 	else if (addr == (addr_t) &dummy32->perc_atmid)
550 		/* PER code, ATMID and AI of the last PER trap */
551 		return (__u32) child->thread.per_event.cause << 16;
552 	else if (addr == (addr_t) &dummy32->address)
553 		/* Address of the last PER trap */
554 		return (__u32) child->thread.per_event.address;
555 	else if (addr == (addr_t) &dummy32->access_id)
556 		/* Access id of the last PER trap */
557 		return (__u32) child->thread.per_event.paid << 24;
558 	return 0;
559 }
560 
561 /*
562  * Same as peek_user but for a 31 bit program.
563  */
564 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
565 {
566 	struct compat_user *dummy32 = NULL;
567 	addr_t offset;
568 	__u32 tmp;
569 
570 	if (addr < (addr_t) &dummy32->regs.acrs) {
571 		struct pt_regs *regs = task_pt_regs(child);
572 		/*
573 		 * psw and gprs are stored on the stack
574 		 */
575 		if (addr == (addr_t) &dummy32->regs.psw.mask) {
576 			/* Fake a 31 bit psw mask. */
577 			tmp = (__u32)(regs->psw.mask >> 32);
578 			tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
579 			tmp |= PSW32_USER_BITS;
580 		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
581 			/* Fake a 31 bit psw address. */
582 			tmp = (__u32) regs->psw.addr |
583 				(__u32)(regs->psw.mask & PSW_MASK_BA);
584 		} else {
585 			/* gpr 0-15 */
586 			tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
587 		}
588 	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
589 		/*
590 		 * access registers are stored in the thread structure
591 		 */
592 		offset = addr - (addr_t) &dummy32->regs.acrs;
593 		tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
594 
595 	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
596 		/*
597 		 * orig_gpr2 is stored on the kernel stack
598 		 */
599 		tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
600 
601 	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
602 		/*
603 		 * prevent reads of padding hole between
604 		 * orig_gpr2 and fp_regs on s390.
605 		 */
606 		tmp = 0;
607 
608 	} else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
609 		/*
610 		 * floating point control reg. is in the thread structure
611 		 */
612 		tmp = child->thread.fpu.fpc;
613 
614 	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
615 		/*
616 		 * floating point regs. are either in child->thread.fpu
617 		 * or the child->thread.fpu.vxrs array
618 		 */
619 		offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
620 		if (is_vx_task(child))
621 			tmp = *(__u32 *)
622 			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
623 		else
624 			tmp = *(__u32 *)
625 			       ((addr_t) &child->thread.fpu.fprs + offset);
626 
627 	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
628 		/*
629 		 * Handle access to the per_info structure.
630 		 */
631 		addr -= (addr_t) &dummy32->regs.per_info;
632 		tmp = __peek_user_per_compat(child, addr);
633 
634 	} else
635 		tmp = 0;
636 
637 	return tmp;
638 }
639 
640 static int peek_user_compat(struct task_struct *child,
641 			    addr_t addr, addr_t data)
642 {
643 	__u32 tmp;
644 
645 	if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
646 		return -EIO;
647 
648 	tmp = __peek_user_compat(child, addr);
649 	return put_user(tmp, (__u32 __user *) data);
650 }
651 
652 /*
653  * Same as poke_user_per but for a 31 bit program.
654  */
655 static inline void __poke_user_per_compat(struct task_struct *child,
656 					  addr_t addr, __u32 data)
657 {
658 	struct compat_per_struct_kernel *dummy32 = NULL;
659 
660 	if (addr == (addr_t) &dummy32->cr9)
661 		/* PER event mask of the user specified per set. */
662 		child->thread.per_user.control =
663 			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
664 	else if (addr == (addr_t) &dummy32->starting_addr)
665 		/* Starting address of the user specified per set. */
666 		child->thread.per_user.start = data;
667 	else if (addr == (addr_t) &dummy32->ending_addr)
668 		/* Ending address of the user specified per set. */
669 		child->thread.per_user.end = data;
670 }
671 
672 /*
673  * Same as poke_user but for a 31 bit program.
674  */
675 static int __poke_user_compat(struct task_struct *child,
676 			      addr_t addr, addr_t data)
677 {
678 	struct compat_user *dummy32 = NULL;
679 	__u32 tmp = (__u32) data;
680 	addr_t offset;
681 
682 	if (addr < (addr_t) &dummy32->regs.acrs) {
683 		struct pt_regs *regs = task_pt_regs(child);
684 		/*
685 		 * psw, gprs, acrs and orig_gpr2 are stored on the stack
686 		 */
687 		if (addr == (addr_t) &dummy32->regs.psw.mask) {
688 			__u32 mask = PSW32_MASK_USER;
689 
690 			mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
691 			/* Build a 64 bit psw mask from 31 bit mask. */
692 			if ((tmp ^ PSW32_USER_BITS) & ~mask)
693 				/* Invalid psw mask. */
694 				return -EINVAL;
695 			if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
696 				/* Invalid address-space-control bits */
697 				return -EINVAL;
698 			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
699 				(regs->psw.mask & PSW_MASK_BA) |
700 				(__u64)(tmp & mask) << 32;
701 		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
702 			/* Build a 64 bit psw address from 31 bit address. */
703 			regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
704 			/* Transfer 31 bit amode bit to psw mask. */
705 			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
706 				(__u64)(tmp & PSW32_ADDR_AMODE);
707 		} else {
708 			/* gpr 0-15 */
709 			*(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
710 		}
711 	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
712 		/*
713 		 * access registers are stored in the thread structure
714 		 */
715 		offset = addr - (addr_t) &dummy32->regs.acrs;
716 		*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
717 
718 	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
719 		/*
720 		 * orig_gpr2 is stored on the kernel stack
721 		 */
722 		*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
723 
724 	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
725 		/*
726 		 * prevent writess of padding hole between
727 		 * orig_gpr2 and fp_regs on s390.
728 		 */
729 		return 0;
730 
731 	} else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
732 		/*
733 		 * floating point control reg. is in the thread structure
734 		 */
735 		if (test_fp_ctl(tmp))
736 			return -EINVAL;
737 		child->thread.fpu.fpc = data;
738 
739 	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
740 		/*
741 		 * floating point regs. are either in child->thread.fpu
742 		 * or the child->thread.fpu.vxrs array
743 		 */
744 		offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
745 		if (is_vx_task(child))
746 			*(__u32 *)((addr_t)
747 				child->thread.fpu.vxrs + 2*offset) = tmp;
748 		else
749 			*(__u32 *)((addr_t)
750 				&child->thread.fpu.fprs + offset) = tmp;
751 
752 	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
753 		/*
754 		 * Handle access to the per_info structure.
755 		 */
756 		addr -= (addr_t) &dummy32->regs.per_info;
757 		__poke_user_per_compat(child, addr, data);
758 	}
759 
760 	return 0;
761 }
762 
763 static int poke_user_compat(struct task_struct *child,
764 			    addr_t addr, addr_t data)
765 {
766 	if (!is_compat_task() || (addr & 3) ||
767 	    addr > sizeof(struct compat_user) - 3)
768 		return -EIO;
769 
770 	return __poke_user_compat(child, addr, data);
771 }
772 
773 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
774 			compat_ulong_t caddr, compat_ulong_t cdata)
775 {
776 	unsigned long addr = caddr;
777 	unsigned long data = cdata;
778 	compat_ptrace_area parea;
779 	int copied, ret;
780 
781 	switch (request) {
782 	case PTRACE_PEEKUSR:
783 		/* read the word at location addr in the USER area. */
784 		return peek_user_compat(child, addr, data);
785 
786 	case PTRACE_POKEUSR:
787 		/* write the word at location addr in the USER area */
788 		return poke_user_compat(child, addr, data);
789 
790 	case PTRACE_PEEKUSR_AREA:
791 	case PTRACE_POKEUSR_AREA:
792 		if (copy_from_user(&parea, (void __force __user *) addr,
793 							sizeof(parea)))
794 			return -EFAULT;
795 		addr = parea.kernel_addr;
796 		data = parea.process_addr;
797 		copied = 0;
798 		while (copied < parea.len) {
799 			if (request == PTRACE_PEEKUSR_AREA)
800 				ret = peek_user_compat(child, addr, data);
801 			else {
802 				__u32 utmp;
803 				if (get_user(utmp,
804 					     (__u32 __force __user *) data))
805 					return -EFAULT;
806 				ret = poke_user_compat(child, addr, utmp);
807 			}
808 			if (ret)
809 				return ret;
810 			addr += sizeof(unsigned int);
811 			data += sizeof(unsigned int);
812 			copied += sizeof(unsigned int);
813 		}
814 		return 0;
815 	case PTRACE_GET_LAST_BREAK:
816 		put_user(task_thread_info(child)->last_break,
817 			 (unsigned int __user *) data);
818 		return 0;
819 	}
820 	return compat_ptrace_request(child, request, addr, data);
821 }
822 #endif
823 
824 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
825 {
826 	long ret = 0;
827 
828 	/* Do the secure computing check first. */
829 	if (secure_computing()) {
830 		/* seccomp failures shouldn't expose any additional code. */
831 		ret = -1;
832 		goto out;
833 	}
834 
835 	/*
836 	 * The sysc_tracesys code in entry.S stored the system
837 	 * call number to gprs[2].
838 	 */
839 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
840 	    (tracehook_report_syscall_entry(regs) ||
841 	     regs->gprs[2] >= NR_syscalls)) {
842 		/*
843 		 * Tracing decided this syscall should not happen or the
844 		 * debugger stored an invalid system call number. Skip
845 		 * the system call and the system call restart handling.
846 		 */
847 		clear_pt_regs_flag(regs, PIF_SYSCALL);
848 		ret = -1;
849 	}
850 
851 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
852 		trace_sys_enter(regs, regs->gprs[2]);
853 
854 	audit_syscall_entry(regs->gprs[2], regs->orig_gpr2,
855 			    regs->gprs[3], regs->gprs[4],
856 			    regs->gprs[5]);
857 out:
858 	return ret ?: regs->gprs[2];
859 }
860 
861 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
862 {
863 	audit_syscall_exit(regs);
864 
865 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
866 		trace_sys_exit(regs, regs->gprs[2]);
867 
868 	if (test_thread_flag(TIF_SYSCALL_TRACE))
869 		tracehook_report_syscall_exit(regs, 0);
870 }
871 
872 /*
873  * user_regset definitions.
874  */
875 
876 static int s390_regs_get(struct task_struct *target,
877 			 const struct user_regset *regset,
878 			 unsigned int pos, unsigned int count,
879 			 void *kbuf, void __user *ubuf)
880 {
881 	if (target == current)
882 		save_access_regs(target->thread.acrs);
883 
884 	if (kbuf) {
885 		unsigned long *k = kbuf;
886 		while (count > 0) {
887 			*k++ = __peek_user(target, pos);
888 			count -= sizeof(*k);
889 			pos += sizeof(*k);
890 		}
891 	} else {
892 		unsigned long __user *u = ubuf;
893 		while (count > 0) {
894 			if (__put_user(__peek_user(target, pos), u++))
895 				return -EFAULT;
896 			count -= sizeof(*u);
897 			pos += sizeof(*u);
898 		}
899 	}
900 	return 0;
901 }
902 
903 static int s390_regs_set(struct task_struct *target,
904 			 const struct user_regset *regset,
905 			 unsigned int pos, unsigned int count,
906 			 const void *kbuf, const void __user *ubuf)
907 {
908 	int rc = 0;
909 
910 	if (target == current)
911 		save_access_regs(target->thread.acrs);
912 
913 	if (kbuf) {
914 		const unsigned long *k = kbuf;
915 		while (count > 0 && !rc) {
916 			rc = __poke_user(target, pos, *k++);
917 			count -= sizeof(*k);
918 			pos += sizeof(*k);
919 		}
920 	} else {
921 		const unsigned long  __user *u = ubuf;
922 		while (count > 0 && !rc) {
923 			unsigned long word;
924 			rc = __get_user(word, u++);
925 			if (rc)
926 				break;
927 			rc = __poke_user(target, pos, word);
928 			count -= sizeof(*u);
929 			pos += sizeof(*u);
930 		}
931 	}
932 
933 	if (rc == 0 && target == current)
934 		restore_access_regs(target->thread.acrs);
935 
936 	return rc;
937 }
938 
939 static int s390_fpregs_get(struct task_struct *target,
940 			   const struct user_regset *regset, unsigned int pos,
941 			   unsigned int count, void *kbuf, void __user *ubuf)
942 {
943 	_s390_fp_regs fp_regs;
944 
945 	if (target == current)
946 		save_fpu_regs();
947 
948 	fp_regs.fpc = target->thread.fpu.fpc;
949 	fpregs_store(&fp_regs, &target->thread.fpu);
950 
951 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
952 				   &fp_regs, 0, -1);
953 }
954 
955 static int s390_fpregs_set(struct task_struct *target,
956 			   const struct user_regset *regset, unsigned int pos,
957 			   unsigned int count, const void *kbuf,
958 			   const void __user *ubuf)
959 {
960 	int rc = 0;
961 	freg_t fprs[__NUM_FPRS];
962 
963 	if (target == current)
964 		save_fpu_regs();
965 
966 	/* If setting FPC, must validate it first. */
967 	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
968 		u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
969 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
970 					0, offsetof(s390_fp_regs, fprs));
971 		if (rc)
972 			return rc;
973 		if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
974 			return -EINVAL;
975 		target->thread.fpu.fpc = ufpc[0];
976 	}
977 
978 	if (rc == 0 && count > 0)
979 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
980 					fprs, offsetof(s390_fp_regs, fprs), -1);
981 	if (rc)
982 		return rc;
983 
984 	if (is_vx_task(target))
985 		convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
986 	else
987 		memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
988 
989 	return rc;
990 }
991 
992 static int s390_last_break_get(struct task_struct *target,
993 			       const struct user_regset *regset,
994 			       unsigned int pos, unsigned int count,
995 			       void *kbuf, void __user *ubuf)
996 {
997 	if (count > 0) {
998 		if (kbuf) {
999 			unsigned long *k = kbuf;
1000 			*k = task_thread_info(target)->last_break;
1001 		} else {
1002 			unsigned long  __user *u = ubuf;
1003 			if (__put_user(task_thread_info(target)->last_break, u))
1004 				return -EFAULT;
1005 		}
1006 	}
1007 	return 0;
1008 }
1009 
1010 static int s390_last_break_set(struct task_struct *target,
1011 			       const struct user_regset *regset,
1012 			       unsigned int pos, unsigned int count,
1013 			       const void *kbuf, const void __user *ubuf)
1014 {
1015 	return 0;
1016 }
1017 
1018 static int s390_tdb_get(struct task_struct *target,
1019 			const struct user_regset *regset,
1020 			unsigned int pos, unsigned int count,
1021 			void *kbuf, void __user *ubuf)
1022 {
1023 	struct pt_regs *regs = task_pt_regs(target);
1024 	unsigned char *data;
1025 
1026 	if (!(regs->int_code & 0x200))
1027 		return -ENODATA;
1028 	data = target->thread.trap_tdb;
1029 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
1030 }
1031 
1032 static int s390_tdb_set(struct task_struct *target,
1033 			const struct user_regset *regset,
1034 			unsigned int pos, unsigned int count,
1035 			const void *kbuf, const void __user *ubuf)
1036 {
1037 	return 0;
1038 }
1039 
1040 static int s390_vxrs_low_get(struct task_struct *target,
1041 			     const struct user_regset *regset,
1042 			     unsigned int pos, unsigned int count,
1043 			     void *kbuf, void __user *ubuf)
1044 {
1045 	__u64 vxrs[__NUM_VXRS_LOW];
1046 	int i;
1047 
1048 	if (!MACHINE_HAS_VX)
1049 		return -ENODEV;
1050 	if (is_vx_task(target)) {
1051 		if (target == current)
1052 			save_fpu_regs();
1053 		for (i = 0; i < __NUM_VXRS_LOW; i++)
1054 			vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1055 	} else
1056 		memset(vxrs, 0, sizeof(vxrs));
1057 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1058 }
1059 
1060 static int s390_vxrs_low_set(struct task_struct *target,
1061 			     const struct user_regset *regset,
1062 			     unsigned int pos, unsigned int count,
1063 			     const void *kbuf, const void __user *ubuf)
1064 {
1065 	__u64 vxrs[__NUM_VXRS_LOW];
1066 	int i, rc;
1067 
1068 	if (!MACHINE_HAS_VX)
1069 		return -ENODEV;
1070 	if (!is_vx_task(target)) {
1071 		rc = alloc_vector_registers(target);
1072 		if (rc)
1073 			return rc;
1074 	} else if (target == current)
1075 		save_fpu_regs();
1076 
1077 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1078 	if (rc == 0)
1079 		for (i = 0; i < __NUM_VXRS_LOW; i++)
1080 			*((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1081 
1082 	return rc;
1083 }
1084 
1085 static int s390_vxrs_high_get(struct task_struct *target,
1086 			      const struct user_regset *regset,
1087 			      unsigned int pos, unsigned int count,
1088 			      void *kbuf, void __user *ubuf)
1089 {
1090 	__vector128 vxrs[__NUM_VXRS_HIGH];
1091 
1092 	if (!MACHINE_HAS_VX)
1093 		return -ENODEV;
1094 	if (is_vx_task(target)) {
1095 		if (target == current)
1096 			save_fpu_regs();
1097 		memcpy(vxrs, target->thread.fpu.vxrs + __NUM_VXRS_LOW,
1098 		       sizeof(vxrs));
1099 	} else
1100 		memset(vxrs, 0, sizeof(vxrs));
1101 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1102 }
1103 
1104 static int s390_vxrs_high_set(struct task_struct *target,
1105 			      const struct user_regset *regset,
1106 			      unsigned int pos, unsigned int count,
1107 			      const void *kbuf, const void __user *ubuf)
1108 {
1109 	int rc;
1110 
1111 	if (!MACHINE_HAS_VX)
1112 		return -ENODEV;
1113 	if (!is_vx_task(target)) {
1114 		rc = alloc_vector_registers(target);
1115 		if (rc)
1116 			return rc;
1117 	} else if (target == current)
1118 		save_fpu_regs();
1119 
1120 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1121 				target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1122 	return rc;
1123 }
1124 
1125 static int s390_system_call_get(struct task_struct *target,
1126 				const struct user_regset *regset,
1127 				unsigned int pos, unsigned int count,
1128 				void *kbuf, void __user *ubuf)
1129 {
1130 	unsigned int *data = &task_thread_info(target)->system_call;
1131 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1132 				   data, 0, sizeof(unsigned int));
1133 }
1134 
1135 static int s390_system_call_set(struct task_struct *target,
1136 				const struct user_regset *regset,
1137 				unsigned int pos, unsigned int count,
1138 				const void *kbuf, const void __user *ubuf)
1139 {
1140 	unsigned int *data = &task_thread_info(target)->system_call;
1141 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1142 				  data, 0, sizeof(unsigned int));
1143 }
1144 
1145 static const struct user_regset s390_regsets[] = {
1146 	{
1147 		.core_note_type = NT_PRSTATUS,
1148 		.n = sizeof(s390_regs) / sizeof(long),
1149 		.size = sizeof(long),
1150 		.align = sizeof(long),
1151 		.get = s390_regs_get,
1152 		.set = s390_regs_set,
1153 	},
1154 	{
1155 		.core_note_type = NT_PRFPREG,
1156 		.n = sizeof(s390_fp_regs) / sizeof(long),
1157 		.size = sizeof(long),
1158 		.align = sizeof(long),
1159 		.get = s390_fpregs_get,
1160 		.set = s390_fpregs_set,
1161 	},
1162 	{
1163 		.core_note_type = NT_S390_SYSTEM_CALL,
1164 		.n = 1,
1165 		.size = sizeof(unsigned int),
1166 		.align = sizeof(unsigned int),
1167 		.get = s390_system_call_get,
1168 		.set = s390_system_call_set,
1169 	},
1170 	{
1171 		.core_note_type = NT_S390_LAST_BREAK,
1172 		.n = 1,
1173 		.size = sizeof(long),
1174 		.align = sizeof(long),
1175 		.get = s390_last_break_get,
1176 		.set = s390_last_break_set,
1177 	},
1178 	{
1179 		.core_note_type = NT_S390_TDB,
1180 		.n = 1,
1181 		.size = 256,
1182 		.align = 1,
1183 		.get = s390_tdb_get,
1184 		.set = s390_tdb_set,
1185 	},
1186 	{
1187 		.core_note_type = NT_S390_VXRS_LOW,
1188 		.n = __NUM_VXRS_LOW,
1189 		.size = sizeof(__u64),
1190 		.align = sizeof(__u64),
1191 		.get = s390_vxrs_low_get,
1192 		.set = s390_vxrs_low_set,
1193 	},
1194 	{
1195 		.core_note_type = NT_S390_VXRS_HIGH,
1196 		.n = __NUM_VXRS_HIGH,
1197 		.size = sizeof(__vector128),
1198 		.align = sizeof(__vector128),
1199 		.get = s390_vxrs_high_get,
1200 		.set = s390_vxrs_high_set,
1201 	},
1202 };
1203 
1204 static const struct user_regset_view user_s390_view = {
1205 	.name = UTS_MACHINE,
1206 	.e_machine = EM_S390,
1207 	.regsets = s390_regsets,
1208 	.n = ARRAY_SIZE(s390_regsets)
1209 };
1210 
1211 #ifdef CONFIG_COMPAT
1212 static int s390_compat_regs_get(struct task_struct *target,
1213 				const struct user_regset *regset,
1214 				unsigned int pos, unsigned int count,
1215 				void *kbuf, void __user *ubuf)
1216 {
1217 	if (target == current)
1218 		save_access_regs(target->thread.acrs);
1219 
1220 	if (kbuf) {
1221 		compat_ulong_t *k = kbuf;
1222 		while (count > 0) {
1223 			*k++ = __peek_user_compat(target, pos);
1224 			count -= sizeof(*k);
1225 			pos += sizeof(*k);
1226 		}
1227 	} else {
1228 		compat_ulong_t __user *u = ubuf;
1229 		while (count > 0) {
1230 			if (__put_user(__peek_user_compat(target, pos), u++))
1231 				return -EFAULT;
1232 			count -= sizeof(*u);
1233 			pos += sizeof(*u);
1234 		}
1235 	}
1236 	return 0;
1237 }
1238 
1239 static int s390_compat_regs_set(struct task_struct *target,
1240 				const struct user_regset *regset,
1241 				unsigned int pos, unsigned int count,
1242 				const void *kbuf, const void __user *ubuf)
1243 {
1244 	int rc = 0;
1245 
1246 	if (target == current)
1247 		save_access_regs(target->thread.acrs);
1248 
1249 	if (kbuf) {
1250 		const compat_ulong_t *k = kbuf;
1251 		while (count > 0 && !rc) {
1252 			rc = __poke_user_compat(target, pos, *k++);
1253 			count -= sizeof(*k);
1254 			pos += sizeof(*k);
1255 		}
1256 	} else {
1257 		const compat_ulong_t  __user *u = ubuf;
1258 		while (count > 0 && !rc) {
1259 			compat_ulong_t word;
1260 			rc = __get_user(word, u++);
1261 			if (rc)
1262 				break;
1263 			rc = __poke_user_compat(target, pos, word);
1264 			count -= sizeof(*u);
1265 			pos += sizeof(*u);
1266 		}
1267 	}
1268 
1269 	if (rc == 0 && target == current)
1270 		restore_access_regs(target->thread.acrs);
1271 
1272 	return rc;
1273 }
1274 
1275 static int s390_compat_regs_high_get(struct task_struct *target,
1276 				     const struct user_regset *regset,
1277 				     unsigned int pos, unsigned int count,
1278 				     void *kbuf, void __user *ubuf)
1279 {
1280 	compat_ulong_t *gprs_high;
1281 
1282 	gprs_high = (compat_ulong_t *)
1283 		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1284 	if (kbuf) {
1285 		compat_ulong_t *k = kbuf;
1286 		while (count > 0) {
1287 			*k++ = *gprs_high;
1288 			gprs_high += 2;
1289 			count -= sizeof(*k);
1290 		}
1291 	} else {
1292 		compat_ulong_t __user *u = ubuf;
1293 		while (count > 0) {
1294 			if (__put_user(*gprs_high, u++))
1295 				return -EFAULT;
1296 			gprs_high += 2;
1297 			count -= sizeof(*u);
1298 		}
1299 	}
1300 	return 0;
1301 }
1302 
1303 static int s390_compat_regs_high_set(struct task_struct *target,
1304 				     const struct user_regset *regset,
1305 				     unsigned int pos, unsigned int count,
1306 				     const void *kbuf, const void __user *ubuf)
1307 {
1308 	compat_ulong_t *gprs_high;
1309 	int rc = 0;
1310 
1311 	gprs_high = (compat_ulong_t *)
1312 		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1313 	if (kbuf) {
1314 		const compat_ulong_t *k = kbuf;
1315 		while (count > 0) {
1316 			*gprs_high = *k++;
1317 			*gprs_high += 2;
1318 			count -= sizeof(*k);
1319 		}
1320 	} else {
1321 		const compat_ulong_t  __user *u = ubuf;
1322 		while (count > 0 && !rc) {
1323 			unsigned long word;
1324 			rc = __get_user(word, u++);
1325 			if (rc)
1326 				break;
1327 			*gprs_high = word;
1328 			*gprs_high += 2;
1329 			count -= sizeof(*u);
1330 		}
1331 	}
1332 
1333 	return rc;
1334 }
1335 
1336 static int s390_compat_last_break_get(struct task_struct *target,
1337 				      const struct user_regset *regset,
1338 				      unsigned int pos, unsigned int count,
1339 				      void *kbuf, void __user *ubuf)
1340 {
1341 	compat_ulong_t last_break;
1342 
1343 	if (count > 0) {
1344 		last_break = task_thread_info(target)->last_break;
1345 		if (kbuf) {
1346 			unsigned long *k = kbuf;
1347 			*k = last_break;
1348 		} else {
1349 			unsigned long  __user *u = ubuf;
1350 			if (__put_user(last_break, u))
1351 				return -EFAULT;
1352 		}
1353 	}
1354 	return 0;
1355 }
1356 
1357 static int s390_compat_last_break_set(struct task_struct *target,
1358 				      const struct user_regset *regset,
1359 				      unsigned int pos, unsigned int count,
1360 				      const void *kbuf, const void __user *ubuf)
1361 {
1362 	return 0;
1363 }
1364 
1365 static const struct user_regset s390_compat_regsets[] = {
1366 	{
1367 		.core_note_type = NT_PRSTATUS,
1368 		.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1369 		.size = sizeof(compat_long_t),
1370 		.align = sizeof(compat_long_t),
1371 		.get = s390_compat_regs_get,
1372 		.set = s390_compat_regs_set,
1373 	},
1374 	{
1375 		.core_note_type = NT_PRFPREG,
1376 		.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1377 		.size = sizeof(compat_long_t),
1378 		.align = sizeof(compat_long_t),
1379 		.get = s390_fpregs_get,
1380 		.set = s390_fpregs_set,
1381 	},
1382 	{
1383 		.core_note_type = NT_S390_SYSTEM_CALL,
1384 		.n = 1,
1385 		.size = sizeof(compat_uint_t),
1386 		.align = sizeof(compat_uint_t),
1387 		.get = s390_system_call_get,
1388 		.set = s390_system_call_set,
1389 	},
1390 	{
1391 		.core_note_type = NT_S390_LAST_BREAK,
1392 		.n = 1,
1393 		.size = sizeof(long),
1394 		.align = sizeof(long),
1395 		.get = s390_compat_last_break_get,
1396 		.set = s390_compat_last_break_set,
1397 	},
1398 	{
1399 		.core_note_type = NT_S390_TDB,
1400 		.n = 1,
1401 		.size = 256,
1402 		.align = 1,
1403 		.get = s390_tdb_get,
1404 		.set = s390_tdb_set,
1405 	},
1406 	{
1407 		.core_note_type = NT_S390_VXRS_LOW,
1408 		.n = __NUM_VXRS_LOW,
1409 		.size = sizeof(__u64),
1410 		.align = sizeof(__u64),
1411 		.get = s390_vxrs_low_get,
1412 		.set = s390_vxrs_low_set,
1413 	},
1414 	{
1415 		.core_note_type = NT_S390_VXRS_HIGH,
1416 		.n = __NUM_VXRS_HIGH,
1417 		.size = sizeof(__vector128),
1418 		.align = sizeof(__vector128),
1419 		.get = s390_vxrs_high_get,
1420 		.set = s390_vxrs_high_set,
1421 	},
1422 	{
1423 		.core_note_type = NT_S390_HIGH_GPRS,
1424 		.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1425 		.size = sizeof(compat_long_t),
1426 		.align = sizeof(compat_long_t),
1427 		.get = s390_compat_regs_high_get,
1428 		.set = s390_compat_regs_high_set,
1429 	},
1430 };
1431 
1432 static const struct user_regset_view user_s390_compat_view = {
1433 	.name = "s390",
1434 	.e_machine = EM_S390,
1435 	.regsets = s390_compat_regsets,
1436 	.n = ARRAY_SIZE(s390_compat_regsets)
1437 };
1438 #endif
1439 
1440 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1441 {
1442 #ifdef CONFIG_COMPAT
1443 	if (test_tsk_thread_flag(task, TIF_31BIT))
1444 		return &user_s390_compat_view;
1445 #endif
1446 	return &user_s390_view;
1447 }
1448 
1449 static const char *gpr_names[NUM_GPRS] = {
1450 	"r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1451 	"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1452 };
1453 
1454 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1455 {
1456 	if (offset >= NUM_GPRS)
1457 		return 0;
1458 	return regs->gprs[offset];
1459 }
1460 
1461 int regs_query_register_offset(const char *name)
1462 {
1463 	unsigned long offset;
1464 
1465 	if (!name || *name != 'r')
1466 		return -EINVAL;
1467 	if (kstrtoul(name + 1, 10, &offset))
1468 		return -EINVAL;
1469 	if (offset >= NUM_GPRS)
1470 		return -EINVAL;
1471 	return offset;
1472 }
1473 
1474 const char *regs_query_register_name(unsigned int offset)
1475 {
1476 	if (offset >= NUM_GPRS)
1477 		return NULL;
1478 	return gpr_names[offset];
1479 }
1480 
1481 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1482 {
1483 	unsigned long ksp = kernel_stack_pointer(regs);
1484 
1485 	return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1486 }
1487 
1488 /**
1489  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1490  * @regs:pt_regs which contains kernel stack pointer.
1491  * @n:stack entry number.
1492  *
1493  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1494  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1495  * this returns 0.
1496  */
1497 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1498 {
1499 	unsigned long addr;
1500 
1501 	addr = kernel_stack_pointer(regs) + n * sizeof(long);
1502 	if (!regs_within_kernel_stack(regs, addr))
1503 		return 0;
1504 	return *(unsigned long *)addr;
1505 }
1506