xref: /openbmc/linux/arch/s390/kernel/ptrace.c (revision 7fde9d6e)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Ptrace user space interface.
4  *
5  *    Copyright IBM Corp. 1999, 2010
6  *    Author(s): Denis Joseph Barrow
7  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
8  */
9 
10 #include "asm/ptrace.h"
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
13 #include <linux/sched/task_stack.h>
14 #include <linux/mm.h>
15 #include <linux/smp.h>
16 #include <linux/errno.h>
17 #include <linux/ptrace.h>
18 #include <linux/user.h>
19 #include <linux/security.h>
20 #include <linux/audit.h>
21 #include <linux/signal.h>
22 #include <linux/elf.h>
23 #include <linux/regset.h>
24 #include <linux/tracehook.h>
25 #include <linux/seccomp.h>
26 #include <linux/compat.h>
27 #include <trace/syscall.h>
28 #include <asm/page.h>
29 #include <linux/uaccess.h>
30 #include <asm/unistd.h>
31 #include <asm/switch_to.h>
32 #include <asm/runtime_instr.h>
33 #include <asm/facility.h>
34 
35 #include "entry.h"
36 
37 #ifdef CONFIG_COMPAT
38 #include "compat_ptrace.h"
39 #endif
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 	union ctlreg0 cr0_old, cr0_new;
47 	union ctlreg2 cr2_old, cr2_new;
48 	int cr0_changed, cr2_changed;
49 
50 	__ctl_store(cr0_old.val, 0, 0);
51 	__ctl_store(cr2_old.val, 2, 2);
52 	cr0_new = cr0_old;
53 	cr2_new = cr2_old;
54 	/* Take care of the enable/disable of transactional execution. */
55 	if (MACHINE_HAS_TE) {
56 		/* Set or clear transaction execution TXC bit 8. */
57 		cr0_new.tcx = 1;
58 		if (task->thread.per_flags & PER_FLAG_NO_TE)
59 			cr0_new.tcx = 0;
60 		/* Set or clear transaction execution TDC bits 62 and 63. */
61 		cr2_new.tdc = 0;
62 		if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
63 			if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
64 				cr2_new.tdc = 1;
65 			else
66 				cr2_new.tdc = 2;
67 		}
68 	}
69 	/* Take care of enable/disable of guarded storage. */
70 	if (MACHINE_HAS_GS) {
71 		cr2_new.gse = 0;
72 		if (task->thread.gs_cb)
73 			cr2_new.gse = 1;
74 	}
75 	/* Load control register 0/2 iff changed */
76 	cr0_changed = cr0_new.val != cr0_old.val;
77 	cr2_changed = cr2_new.val != cr2_old.val;
78 	if (cr0_changed)
79 		__ctl_load(cr0_new.val, 0, 0);
80 	if (cr2_changed)
81 		__ctl_load(cr2_new.val, 2, 2);
82 	/* Copy user specified PER registers */
83 	new.control = thread->per_user.control;
84 	new.start = thread->per_user.start;
85 	new.end = thread->per_user.end;
86 
87 	/* merge TIF_SINGLE_STEP into user specified PER registers. */
88 	if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
89 	    test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
90 		if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
91 			new.control |= PER_EVENT_BRANCH;
92 		else
93 			new.control |= PER_EVENT_IFETCH;
94 		new.control |= PER_CONTROL_SUSPENSION;
95 		new.control |= PER_EVENT_TRANSACTION_END;
96 		if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
97 			new.control |= PER_EVENT_IFETCH;
98 		new.start = 0;
99 		new.end = -1UL;
100 	}
101 
102 	/* Take care of the PER enablement bit in the PSW. */
103 	if (!(new.control & PER_EVENT_MASK)) {
104 		regs->psw.mask &= ~PSW_MASK_PER;
105 		return;
106 	}
107 	regs->psw.mask |= PSW_MASK_PER;
108 	__ctl_store(old, 9, 11);
109 	if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
110 		__ctl_load(new, 9, 11);
111 }
112 
113 void user_enable_single_step(struct task_struct *task)
114 {
115 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
116 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
117 }
118 
119 void user_disable_single_step(struct task_struct *task)
120 {
121 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
122 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
123 }
124 
125 void user_enable_block_step(struct task_struct *task)
126 {
127 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
128 	set_tsk_thread_flag(task, TIF_BLOCK_STEP);
129 }
130 
131 /*
132  * Called by kernel/ptrace.c when detaching..
133  *
134  * Clear all debugging related fields.
135  */
136 void ptrace_disable(struct task_struct *task)
137 {
138 	memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
139 	memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
140 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
141 	clear_tsk_thread_flag(task, TIF_PER_TRAP);
142 	task->thread.per_flags = 0;
143 }
144 
145 #define __ADDR_MASK 7
146 
147 static inline unsigned long __peek_user_per(struct task_struct *child,
148 					    addr_t addr)
149 {
150 	struct per_struct_kernel *dummy = NULL;
151 
152 	if (addr == (addr_t) &dummy->cr9)
153 		/* Control bits of the active per set. */
154 		return test_thread_flag(TIF_SINGLE_STEP) ?
155 			PER_EVENT_IFETCH : child->thread.per_user.control;
156 	else if (addr == (addr_t) &dummy->cr10)
157 		/* Start address of the active per set. */
158 		return test_thread_flag(TIF_SINGLE_STEP) ?
159 			0 : child->thread.per_user.start;
160 	else if (addr == (addr_t) &dummy->cr11)
161 		/* End address of the active per set. */
162 		return test_thread_flag(TIF_SINGLE_STEP) ?
163 			-1UL : child->thread.per_user.end;
164 	else if (addr == (addr_t) &dummy->bits)
165 		/* Single-step bit. */
166 		return test_thread_flag(TIF_SINGLE_STEP) ?
167 			(1UL << (BITS_PER_LONG - 1)) : 0;
168 	else if (addr == (addr_t) &dummy->starting_addr)
169 		/* Start address of the user specified per set. */
170 		return child->thread.per_user.start;
171 	else if (addr == (addr_t) &dummy->ending_addr)
172 		/* End address of the user specified per set. */
173 		return child->thread.per_user.end;
174 	else if (addr == (addr_t) &dummy->perc_atmid)
175 		/* PER code, ATMID and AI of the last PER trap */
176 		return (unsigned long)
177 			child->thread.per_event.cause << (BITS_PER_LONG - 16);
178 	else if (addr == (addr_t) &dummy->address)
179 		/* Address of the last PER trap */
180 		return child->thread.per_event.address;
181 	else if (addr == (addr_t) &dummy->access_id)
182 		/* Access id of the last PER trap */
183 		return (unsigned long)
184 			child->thread.per_event.paid << (BITS_PER_LONG - 8);
185 	return 0;
186 }
187 
188 /*
189  * Read the word at offset addr from the user area of a process. The
190  * trouble here is that the information is littered over different
191  * locations. The process registers are found on the kernel stack,
192  * the floating point stuff and the trace settings are stored in
193  * the task structure. In addition the different structures in
194  * struct user contain pad bytes that should be read as zeroes.
195  * Lovely...
196  */
197 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
198 {
199 	struct user *dummy = NULL;
200 	addr_t offset, tmp;
201 
202 	if (addr < (addr_t) &dummy->regs.acrs) {
203 		/*
204 		 * psw and gprs are stored on the stack
205 		 */
206 		tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
207 		if (addr == (addr_t) &dummy->regs.psw.mask) {
208 			/* Return a clean psw mask. */
209 			tmp &= PSW_MASK_USER | PSW_MASK_RI;
210 			tmp |= PSW_USER_BITS;
211 		}
212 
213 	} else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
214 		/*
215 		 * access registers are stored in the thread structure
216 		 */
217 		offset = addr - (addr_t) &dummy->regs.acrs;
218 		/*
219 		 * Very special case: old & broken 64 bit gdb reading
220 		 * from acrs[15]. Result is a 64 bit value. Read the
221 		 * 32 bit acrs[15] value and shift it by 32. Sick...
222 		 */
223 		if (addr == (addr_t) &dummy->regs.acrs[15])
224 			tmp = ((unsigned long) child->thread.acrs[15]) << 32;
225 		else
226 			tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
227 
228 	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
229 		/*
230 		 * orig_gpr2 is stored on the kernel stack
231 		 */
232 		tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
233 
234 	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
235 		/*
236 		 * prevent reads of padding hole between
237 		 * orig_gpr2 and fp_regs on s390.
238 		 */
239 		tmp = 0;
240 
241 	} else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
242 		/*
243 		 * floating point control reg. is in the thread structure
244 		 */
245 		tmp = child->thread.fpu.fpc;
246 		tmp <<= BITS_PER_LONG - 32;
247 
248 	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
249 		/*
250 		 * floating point regs. are either in child->thread.fpu
251 		 * or the child->thread.fpu.vxrs array
252 		 */
253 		offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
254 		if (MACHINE_HAS_VX)
255 			tmp = *(addr_t *)
256 			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
257 		else
258 			tmp = *(addr_t *)
259 			       ((addr_t) child->thread.fpu.fprs + offset);
260 
261 	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
262 		/*
263 		 * Handle access to the per_info structure.
264 		 */
265 		addr -= (addr_t) &dummy->regs.per_info;
266 		tmp = __peek_user_per(child, addr);
267 
268 	} else
269 		tmp = 0;
270 
271 	return tmp;
272 }
273 
274 static int
275 peek_user(struct task_struct *child, addr_t addr, addr_t data)
276 {
277 	addr_t tmp, mask;
278 
279 	/*
280 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
281 	 * an alignment of 4. Programmers from hell...
282 	 */
283 	mask = __ADDR_MASK;
284 	if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
285 	    addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
286 		mask = 3;
287 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
288 		return -EIO;
289 
290 	tmp = __peek_user(child, addr);
291 	return put_user(tmp, (addr_t __user *) data);
292 }
293 
294 static inline void __poke_user_per(struct task_struct *child,
295 				   addr_t addr, addr_t data)
296 {
297 	struct per_struct_kernel *dummy = NULL;
298 
299 	/*
300 	 * There are only three fields in the per_info struct that the
301 	 * debugger user can write to.
302 	 * 1) cr9: the debugger wants to set a new PER event mask
303 	 * 2) starting_addr: the debugger wants to set a new starting
304 	 *    address to use with the PER event mask.
305 	 * 3) ending_addr: the debugger wants to set a new ending
306 	 *    address to use with the PER event mask.
307 	 * The user specified PER event mask and the start and end
308 	 * addresses are used only if single stepping is not in effect.
309 	 * Writes to any other field in per_info are ignored.
310 	 */
311 	if (addr == (addr_t) &dummy->cr9)
312 		/* PER event mask of the user specified per set. */
313 		child->thread.per_user.control =
314 			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
315 	else if (addr == (addr_t) &dummy->starting_addr)
316 		/* Starting address of the user specified per set. */
317 		child->thread.per_user.start = data;
318 	else if (addr == (addr_t) &dummy->ending_addr)
319 		/* Ending address of the user specified per set. */
320 		child->thread.per_user.end = data;
321 }
322 
323 /*
324  * Write a word to the user area of a process at location addr. This
325  * operation does have an additional problem compared to peek_user.
326  * Stores to the program status word and on the floating point
327  * control register needs to get checked for validity.
328  */
329 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
330 {
331 	struct user *dummy = NULL;
332 	addr_t offset;
333 
334 
335 	if (addr < (addr_t) &dummy->regs.acrs) {
336 		struct pt_regs *regs = task_pt_regs(child);
337 		/*
338 		 * psw and gprs are stored on the stack
339 		 */
340 		if (addr == (addr_t) &dummy->regs.psw.mask) {
341 			unsigned long mask = PSW_MASK_USER;
342 
343 			mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
344 			if ((data ^ PSW_USER_BITS) & ~mask)
345 				/* Invalid psw mask. */
346 				return -EINVAL;
347 			if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
348 				/* Invalid address-space-control bits */
349 				return -EINVAL;
350 			if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
351 				/* Invalid addressing mode bits */
352 				return -EINVAL;
353 		}
354 
355 		if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
356 			addr == offsetof(struct user, regs.gprs[2])) {
357 			struct pt_regs *regs = task_pt_regs(child);
358 
359 			regs->int_code = 0x20000 | (data & 0xffff);
360 		}
361 		*(addr_t *)((addr_t) &regs->psw + addr) = data;
362 	} else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
363 		/*
364 		 * access registers are stored in the thread structure
365 		 */
366 		offset = addr - (addr_t) &dummy->regs.acrs;
367 		/*
368 		 * Very special case: old & broken 64 bit gdb writing
369 		 * to acrs[15] with a 64 bit value. Ignore the lower
370 		 * half of the value and write the upper 32 bit to
371 		 * acrs[15]. Sick...
372 		 */
373 		if (addr == (addr_t) &dummy->regs.acrs[15])
374 			child->thread.acrs[15] = (unsigned int) (data >> 32);
375 		else
376 			*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
377 
378 	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
379 		/*
380 		 * orig_gpr2 is stored on the kernel stack
381 		 */
382 		task_pt_regs(child)->orig_gpr2 = data;
383 
384 	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
385 		/*
386 		 * prevent writes of padding hole between
387 		 * orig_gpr2 and fp_regs on s390.
388 		 */
389 		return 0;
390 
391 	} else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
392 		/*
393 		 * floating point control reg. is in the thread structure
394 		 */
395 		if ((unsigned int) data != 0 ||
396 		    test_fp_ctl(data >> (BITS_PER_LONG - 32)))
397 			return -EINVAL;
398 		child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
399 
400 	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
401 		/*
402 		 * floating point regs. are either in child->thread.fpu
403 		 * or the child->thread.fpu.vxrs array
404 		 */
405 		offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
406 		if (MACHINE_HAS_VX)
407 			*(addr_t *)((addr_t)
408 				child->thread.fpu.vxrs + 2*offset) = data;
409 		else
410 			*(addr_t *)((addr_t)
411 				child->thread.fpu.fprs + offset) = data;
412 
413 	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
414 		/*
415 		 * Handle access to the per_info structure.
416 		 */
417 		addr -= (addr_t) &dummy->regs.per_info;
418 		__poke_user_per(child, addr, data);
419 
420 	}
421 
422 	return 0;
423 }
424 
425 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
426 {
427 	addr_t mask;
428 
429 	/*
430 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
431 	 * an alignment of 4. Programmers from hell indeed...
432 	 */
433 	mask = __ADDR_MASK;
434 	if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
435 	    addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
436 		mask = 3;
437 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
438 		return -EIO;
439 
440 	return __poke_user(child, addr, data);
441 }
442 
443 long arch_ptrace(struct task_struct *child, long request,
444 		 unsigned long addr, unsigned long data)
445 {
446 	ptrace_area parea;
447 	int copied, ret;
448 
449 	switch (request) {
450 	case PTRACE_PEEKUSR:
451 		/* read the word at location addr in the USER area. */
452 		return peek_user(child, addr, data);
453 
454 	case PTRACE_POKEUSR:
455 		/* write the word at location addr in the USER area */
456 		return poke_user(child, addr, data);
457 
458 	case PTRACE_PEEKUSR_AREA:
459 	case PTRACE_POKEUSR_AREA:
460 		if (copy_from_user(&parea, (void __force __user *) addr,
461 							sizeof(parea)))
462 			return -EFAULT;
463 		addr = parea.kernel_addr;
464 		data = parea.process_addr;
465 		copied = 0;
466 		while (copied < parea.len) {
467 			if (request == PTRACE_PEEKUSR_AREA)
468 				ret = peek_user(child, addr, data);
469 			else {
470 				addr_t utmp;
471 				if (get_user(utmp,
472 					     (addr_t __force __user *) data))
473 					return -EFAULT;
474 				ret = poke_user(child, addr, utmp);
475 			}
476 			if (ret)
477 				return ret;
478 			addr += sizeof(unsigned long);
479 			data += sizeof(unsigned long);
480 			copied += sizeof(unsigned long);
481 		}
482 		return 0;
483 	case PTRACE_GET_LAST_BREAK:
484 		put_user(child->thread.last_break,
485 			 (unsigned long __user *) data);
486 		return 0;
487 	case PTRACE_ENABLE_TE:
488 		if (!MACHINE_HAS_TE)
489 			return -EIO;
490 		child->thread.per_flags &= ~PER_FLAG_NO_TE;
491 		return 0;
492 	case PTRACE_DISABLE_TE:
493 		if (!MACHINE_HAS_TE)
494 			return -EIO;
495 		child->thread.per_flags |= PER_FLAG_NO_TE;
496 		child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
497 		return 0;
498 	case PTRACE_TE_ABORT_RAND:
499 		if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
500 			return -EIO;
501 		switch (data) {
502 		case 0UL:
503 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
504 			break;
505 		case 1UL:
506 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
507 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
508 			break;
509 		case 2UL:
510 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
511 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
512 			break;
513 		default:
514 			return -EINVAL;
515 		}
516 		return 0;
517 	default:
518 		return ptrace_request(child, request, addr, data);
519 	}
520 }
521 
522 #ifdef CONFIG_COMPAT
523 /*
524  * Now the fun part starts... a 31 bit program running in the
525  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
526  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
527  * to handle, the difference to the 64 bit versions of the requests
528  * is that the access is done in multiples of 4 byte instead of
529  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
530  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
531  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
532  * is a 31 bit program too, the content of struct user can be
533  * emulated. A 31 bit program peeking into the struct user of
534  * a 64 bit program is a no-no.
535  */
536 
537 /*
538  * Same as peek_user_per but for a 31 bit program.
539  */
540 static inline __u32 __peek_user_per_compat(struct task_struct *child,
541 					   addr_t addr)
542 {
543 	struct compat_per_struct_kernel *dummy32 = NULL;
544 
545 	if (addr == (addr_t) &dummy32->cr9)
546 		/* Control bits of the active per set. */
547 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
548 			PER_EVENT_IFETCH : child->thread.per_user.control;
549 	else if (addr == (addr_t) &dummy32->cr10)
550 		/* Start address of the active per set. */
551 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
552 			0 : child->thread.per_user.start;
553 	else if (addr == (addr_t) &dummy32->cr11)
554 		/* End address of the active per set. */
555 		return test_thread_flag(TIF_SINGLE_STEP) ?
556 			PSW32_ADDR_INSN : child->thread.per_user.end;
557 	else if (addr == (addr_t) &dummy32->bits)
558 		/* Single-step bit. */
559 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
560 			0x80000000 : 0;
561 	else if (addr == (addr_t) &dummy32->starting_addr)
562 		/* Start address of the user specified per set. */
563 		return (__u32) child->thread.per_user.start;
564 	else if (addr == (addr_t) &dummy32->ending_addr)
565 		/* End address of the user specified per set. */
566 		return (__u32) child->thread.per_user.end;
567 	else if (addr == (addr_t) &dummy32->perc_atmid)
568 		/* PER code, ATMID and AI of the last PER trap */
569 		return (__u32) child->thread.per_event.cause << 16;
570 	else if (addr == (addr_t) &dummy32->address)
571 		/* Address of the last PER trap */
572 		return (__u32) child->thread.per_event.address;
573 	else if (addr == (addr_t) &dummy32->access_id)
574 		/* Access id of the last PER trap */
575 		return (__u32) child->thread.per_event.paid << 24;
576 	return 0;
577 }
578 
579 /*
580  * Same as peek_user but for a 31 bit program.
581  */
582 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
583 {
584 	struct compat_user *dummy32 = NULL;
585 	addr_t offset;
586 	__u32 tmp;
587 
588 	if (addr < (addr_t) &dummy32->regs.acrs) {
589 		struct pt_regs *regs = task_pt_regs(child);
590 		/*
591 		 * psw and gprs are stored on the stack
592 		 */
593 		if (addr == (addr_t) &dummy32->regs.psw.mask) {
594 			/* Fake a 31 bit psw mask. */
595 			tmp = (__u32)(regs->psw.mask >> 32);
596 			tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
597 			tmp |= PSW32_USER_BITS;
598 		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
599 			/* Fake a 31 bit psw address. */
600 			tmp = (__u32) regs->psw.addr |
601 				(__u32)(regs->psw.mask & PSW_MASK_BA);
602 		} else {
603 			/* gpr 0-15 */
604 			tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
605 		}
606 	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
607 		/*
608 		 * access registers are stored in the thread structure
609 		 */
610 		offset = addr - (addr_t) &dummy32->regs.acrs;
611 		tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
612 
613 	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
614 		/*
615 		 * orig_gpr2 is stored on the kernel stack
616 		 */
617 		tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
618 
619 	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
620 		/*
621 		 * prevent reads of padding hole between
622 		 * orig_gpr2 and fp_regs on s390.
623 		 */
624 		tmp = 0;
625 
626 	} else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
627 		/*
628 		 * floating point control reg. is in the thread structure
629 		 */
630 		tmp = child->thread.fpu.fpc;
631 
632 	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
633 		/*
634 		 * floating point regs. are either in child->thread.fpu
635 		 * or the child->thread.fpu.vxrs array
636 		 */
637 		offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
638 		if (MACHINE_HAS_VX)
639 			tmp = *(__u32 *)
640 			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
641 		else
642 			tmp = *(__u32 *)
643 			       ((addr_t) child->thread.fpu.fprs + offset);
644 
645 	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
646 		/*
647 		 * Handle access to the per_info structure.
648 		 */
649 		addr -= (addr_t) &dummy32->regs.per_info;
650 		tmp = __peek_user_per_compat(child, addr);
651 
652 	} else
653 		tmp = 0;
654 
655 	return tmp;
656 }
657 
658 static int peek_user_compat(struct task_struct *child,
659 			    addr_t addr, addr_t data)
660 {
661 	__u32 tmp;
662 
663 	if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
664 		return -EIO;
665 
666 	tmp = __peek_user_compat(child, addr);
667 	return put_user(tmp, (__u32 __user *) data);
668 }
669 
670 /*
671  * Same as poke_user_per but for a 31 bit program.
672  */
673 static inline void __poke_user_per_compat(struct task_struct *child,
674 					  addr_t addr, __u32 data)
675 {
676 	struct compat_per_struct_kernel *dummy32 = NULL;
677 
678 	if (addr == (addr_t) &dummy32->cr9)
679 		/* PER event mask of the user specified per set. */
680 		child->thread.per_user.control =
681 			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
682 	else if (addr == (addr_t) &dummy32->starting_addr)
683 		/* Starting address of the user specified per set. */
684 		child->thread.per_user.start = data;
685 	else if (addr == (addr_t) &dummy32->ending_addr)
686 		/* Ending address of the user specified per set. */
687 		child->thread.per_user.end = data;
688 }
689 
690 /*
691  * Same as poke_user but for a 31 bit program.
692  */
693 static int __poke_user_compat(struct task_struct *child,
694 			      addr_t addr, addr_t data)
695 {
696 	struct compat_user *dummy32 = NULL;
697 	__u32 tmp = (__u32) data;
698 	addr_t offset;
699 
700 	if (addr < (addr_t) &dummy32->regs.acrs) {
701 		struct pt_regs *regs = task_pt_regs(child);
702 		/*
703 		 * psw, gprs, acrs and orig_gpr2 are stored on the stack
704 		 */
705 		if (addr == (addr_t) &dummy32->regs.psw.mask) {
706 			__u32 mask = PSW32_MASK_USER;
707 
708 			mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
709 			/* Build a 64 bit psw mask from 31 bit mask. */
710 			if ((tmp ^ PSW32_USER_BITS) & ~mask)
711 				/* Invalid psw mask. */
712 				return -EINVAL;
713 			if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
714 				/* Invalid address-space-control bits */
715 				return -EINVAL;
716 			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
717 				(regs->psw.mask & PSW_MASK_BA) |
718 				(__u64)(tmp & mask) << 32;
719 		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
720 			/* Build a 64 bit psw address from 31 bit address. */
721 			regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
722 			/* Transfer 31 bit amode bit to psw mask. */
723 			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
724 				(__u64)(tmp & PSW32_ADDR_AMODE);
725 		} else {
726 			if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
727 				addr == offsetof(struct compat_user, regs.gprs[2])) {
728 				struct pt_regs *regs = task_pt_regs(child);
729 
730 				regs->int_code = 0x20000 | (data & 0xffff);
731 			}
732 			/* gpr 0-15 */
733 			*(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
734 		}
735 	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
736 		/*
737 		 * access registers are stored in the thread structure
738 		 */
739 		offset = addr - (addr_t) &dummy32->regs.acrs;
740 		*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
741 
742 	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
743 		/*
744 		 * orig_gpr2 is stored on the kernel stack
745 		 */
746 		*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
747 
748 	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
749 		/*
750 		 * prevent writess of padding hole between
751 		 * orig_gpr2 and fp_regs on s390.
752 		 */
753 		return 0;
754 
755 	} else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
756 		/*
757 		 * floating point control reg. is in the thread structure
758 		 */
759 		if (test_fp_ctl(tmp))
760 			return -EINVAL;
761 		child->thread.fpu.fpc = data;
762 
763 	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
764 		/*
765 		 * floating point regs. are either in child->thread.fpu
766 		 * or the child->thread.fpu.vxrs array
767 		 */
768 		offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
769 		if (MACHINE_HAS_VX)
770 			*(__u32 *)((addr_t)
771 				child->thread.fpu.vxrs + 2*offset) = tmp;
772 		else
773 			*(__u32 *)((addr_t)
774 				child->thread.fpu.fprs + offset) = tmp;
775 
776 	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
777 		/*
778 		 * Handle access to the per_info structure.
779 		 */
780 		addr -= (addr_t) &dummy32->regs.per_info;
781 		__poke_user_per_compat(child, addr, data);
782 	}
783 
784 	return 0;
785 }
786 
787 static int poke_user_compat(struct task_struct *child,
788 			    addr_t addr, addr_t data)
789 {
790 	if (!is_compat_task() || (addr & 3) ||
791 	    addr > sizeof(struct compat_user) - 3)
792 		return -EIO;
793 
794 	return __poke_user_compat(child, addr, data);
795 }
796 
797 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
798 			compat_ulong_t caddr, compat_ulong_t cdata)
799 {
800 	unsigned long addr = caddr;
801 	unsigned long data = cdata;
802 	compat_ptrace_area parea;
803 	int copied, ret;
804 
805 	switch (request) {
806 	case PTRACE_PEEKUSR:
807 		/* read the word at location addr in the USER area. */
808 		return peek_user_compat(child, addr, data);
809 
810 	case PTRACE_POKEUSR:
811 		/* write the word at location addr in the USER area */
812 		return poke_user_compat(child, addr, data);
813 
814 	case PTRACE_PEEKUSR_AREA:
815 	case PTRACE_POKEUSR_AREA:
816 		if (copy_from_user(&parea, (void __force __user *) addr,
817 							sizeof(parea)))
818 			return -EFAULT;
819 		addr = parea.kernel_addr;
820 		data = parea.process_addr;
821 		copied = 0;
822 		while (copied < parea.len) {
823 			if (request == PTRACE_PEEKUSR_AREA)
824 				ret = peek_user_compat(child, addr, data);
825 			else {
826 				__u32 utmp;
827 				if (get_user(utmp,
828 					     (__u32 __force __user *) data))
829 					return -EFAULT;
830 				ret = poke_user_compat(child, addr, utmp);
831 			}
832 			if (ret)
833 				return ret;
834 			addr += sizeof(unsigned int);
835 			data += sizeof(unsigned int);
836 			copied += sizeof(unsigned int);
837 		}
838 		return 0;
839 	case PTRACE_GET_LAST_BREAK:
840 		put_user(child->thread.last_break,
841 			 (unsigned int __user *) data);
842 		return 0;
843 	}
844 	return compat_ptrace_request(child, request, addr, data);
845 }
846 #endif
847 
848 /*
849  * user_regset definitions.
850  */
851 
852 static int s390_regs_get(struct task_struct *target,
853 			 const struct user_regset *regset,
854 			 struct membuf to)
855 {
856 	unsigned pos;
857 	if (target == current)
858 		save_access_regs(target->thread.acrs);
859 
860 	for (pos = 0; pos < sizeof(s390_regs); pos += sizeof(long))
861 		membuf_store(&to, __peek_user(target, pos));
862 	return 0;
863 }
864 
865 static int s390_regs_set(struct task_struct *target,
866 			 const struct user_regset *regset,
867 			 unsigned int pos, unsigned int count,
868 			 const void *kbuf, const void __user *ubuf)
869 {
870 	int rc = 0;
871 
872 	if (target == current)
873 		save_access_regs(target->thread.acrs);
874 
875 	if (kbuf) {
876 		const unsigned long *k = kbuf;
877 		while (count > 0 && !rc) {
878 			rc = __poke_user(target, pos, *k++);
879 			count -= sizeof(*k);
880 			pos += sizeof(*k);
881 		}
882 	} else {
883 		const unsigned long  __user *u = ubuf;
884 		while (count > 0 && !rc) {
885 			unsigned long word;
886 			rc = __get_user(word, u++);
887 			if (rc)
888 				break;
889 			rc = __poke_user(target, pos, word);
890 			count -= sizeof(*u);
891 			pos += sizeof(*u);
892 		}
893 	}
894 
895 	if (rc == 0 && target == current)
896 		restore_access_regs(target->thread.acrs);
897 
898 	return rc;
899 }
900 
901 static int s390_fpregs_get(struct task_struct *target,
902 			   const struct user_regset *regset,
903 			   struct membuf to)
904 {
905 	_s390_fp_regs fp_regs;
906 
907 	if (target == current)
908 		save_fpu_regs();
909 
910 	fp_regs.fpc = target->thread.fpu.fpc;
911 	fpregs_store(&fp_regs, &target->thread.fpu);
912 
913 	return membuf_write(&to, &fp_regs, sizeof(fp_regs));
914 }
915 
916 static int s390_fpregs_set(struct task_struct *target,
917 			   const struct user_regset *regset, unsigned int pos,
918 			   unsigned int count, const void *kbuf,
919 			   const void __user *ubuf)
920 {
921 	int rc = 0;
922 	freg_t fprs[__NUM_FPRS];
923 
924 	if (target == current)
925 		save_fpu_regs();
926 
927 	if (MACHINE_HAS_VX)
928 		convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
929 	else
930 		memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
931 
932 	/* If setting FPC, must validate it first. */
933 	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
934 		u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
935 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
936 					0, offsetof(s390_fp_regs, fprs));
937 		if (rc)
938 			return rc;
939 		if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
940 			return -EINVAL;
941 		target->thread.fpu.fpc = ufpc[0];
942 	}
943 
944 	if (rc == 0 && count > 0)
945 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
946 					fprs, offsetof(s390_fp_regs, fprs), -1);
947 	if (rc)
948 		return rc;
949 
950 	if (MACHINE_HAS_VX)
951 		convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
952 	else
953 		memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
954 
955 	return rc;
956 }
957 
958 static int s390_last_break_get(struct task_struct *target,
959 			       const struct user_regset *regset,
960 			       struct membuf to)
961 {
962 	return membuf_store(&to, target->thread.last_break);
963 }
964 
965 static int s390_last_break_set(struct task_struct *target,
966 			       const struct user_regset *regset,
967 			       unsigned int pos, unsigned int count,
968 			       const void *kbuf, const void __user *ubuf)
969 {
970 	return 0;
971 }
972 
973 static int s390_tdb_get(struct task_struct *target,
974 			const struct user_regset *regset,
975 			struct membuf to)
976 {
977 	struct pt_regs *regs = task_pt_regs(target);
978 
979 	if (!(regs->int_code & 0x200))
980 		return -ENODATA;
981 	return membuf_write(&to, target->thread.trap_tdb, 256);
982 }
983 
984 static int s390_tdb_set(struct task_struct *target,
985 			const struct user_regset *regset,
986 			unsigned int pos, unsigned int count,
987 			const void *kbuf, const void __user *ubuf)
988 {
989 	return 0;
990 }
991 
992 static int s390_vxrs_low_get(struct task_struct *target,
993 			     const struct user_regset *regset,
994 			     struct membuf to)
995 {
996 	__u64 vxrs[__NUM_VXRS_LOW];
997 	int i;
998 
999 	if (!MACHINE_HAS_VX)
1000 		return -ENODEV;
1001 	if (target == current)
1002 		save_fpu_regs();
1003 	for (i = 0; i < __NUM_VXRS_LOW; i++)
1004 		vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1005 	return membuf_write(&to, vxrs, sizeof(vxrs));
1006 }
1007 
1008 static int s390_vxrs_low_set(struct task_struct *target,
1009 			     const struct user_regset *regset,
1010 			     unsigned int pos, unsigned int count,
1011 			     const void *kbuf, const void __user *ubuf)
1012 {
1013 	__u64 vxrs[__NUM_VXRS_LOW];
1014 	int i, rc;
1015 
1016 	if (!MACHINE_HAS_VX)
1017 		return -ENODEV;
1018 	if (target == current)
1019 		save_fpu_regs();
1020 
1021 	for (i = 0; i < __NUM_VXRS_LOW; i++)
1022 		vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1023 
1024 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1025 	if (rc == 0)
1026 		for (i = 0; i < __NUM_VXRS_LOW; i++)
1027 			*((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1028 
1029 	return rc;
1030 }
1031 
1032 static int s390_vxrs_high_get(struct task_struct *target,
1033 			      const struct user_regset *regset,
1034 			      struct membuf to)
1035 {
1036 	if (!MACHINE_HAS_VX)
1037 		return -ENODEV;
1038 	if (target == current)
1039 		save_fpu_regs();
1040 	return membuf_write(&to, target->thread.fpu.vxrs + __NUM_VXRS_LOW,
1041 			    __NUM_VXRS_HIGH * sizeof(__vector128));
1042 }
1043 
1044 static int s390_vxrs_high_set(struct task_struct *target,
1045 			      const struct user_regset *regset,
1046 			      unsigned int pos, unsigned int count,
1047 			      const void *kbuf, const void __user *ubuf)
1048 {
1049 	int rc;
1050 
1051 	if (!MACHINE_HAS_VX)
1052 		return -ENODEV;
1053 	if (target == current)
1054 		save_fpu_regs();
1055 
1056 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1057 				target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1058 	return rc;
1059 }
1060 
1061 static int s390_system_call_get(struct task_struct *target,
1062 				const struct user_regset *regset,
1063 				struct membuf to)
1064 {
1065 	return membuf_store(&to, target->thread.system_call);
1066 }
1067 
1068 static int s390_system_call_set(struct task_struct *target,
1069 				const struct user_regset *regset,
1070 				unsigned int pos, unsigned int count,
1071 				const void *kbuf, const void __user *ubuf)
1072 {
1073 	unsigned int *data = &target->thread.system_call;
1074 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1075 				  data, 0, sizeof(unsigned int));
1076 }
1077 
1078 static int s390_gs_cb_get(struct task_struct *target,
1079 			  const struct user_regset *regset,
1080 			  struct membuf to)
1081 {
1082 	struct gs_cb *data = target->thread.gs_cb;
1083 
1084 	if (!MACHINE_HAS_GS)
1085 		return -ENODEV;
1086 	if (!data)
1087 		return -ENODATA;
1088 	if (target == current)
1089 		save_gs_cb(data);
1090 	return membuf_write(&to, data, sizeof(struct gs_cb));
1091 }
1092 
1093 static int s390_gs_cb_set(struct task_struct *target,
1094 			  const struct user_regset *regset,
1095 			  unsigned int pos, unsigned int count,
1096 			  const void *kbuf, const void __user *ubuf)
1097 {
1098 	struct gs_cb gs_cb = { }, *data = NULL;
1099 	int rc;
1100 
1101 	if (!MACHINE_HAS_GS)
1102 		return -ENODEV;
1103 	if (!target->thread.gs_cb) {
1104 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1105 		if (!data)
1106 			return -ENOMEM;
1107 	}
1108 	if (!target->thread.gs_cb)
1109 		gs_cb.gsd = 25;
1110 	else if (target == current)
1111 		save_gs_cb(&gs_cb);
1112 	else
1113 		gs_cb = *target->thread.gs_cb;
1114 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1115 				&gs_cb, 0, sizeof(gs_cb));
1116 	if (rc) {
1117 		kfree(data);
1118 		return -EFAULT;
1119 	}
1120 	preempt_disable();
1121 	if (!target->thread.gs_cb)
1122 		target->thread.gs_cb = data;
1123 	*target->thread.gs_cb = gs_cb;
1124 	if (target == current) {
1125 		__ctl_set_bit(2, 4);
1126 		restore_gs_cb(target->thread.gs_cb);
1127 	}
1128 	preempt_enable();
1129 	return rc;
1130 }
1131 
1132 static int s390_gs_bc_get(struct task_struct *target,
1133 			  const struct user_regset *regset,
1134 			  struct membuf to)
1135 {
1136 	struct gs_cb *data = target->thread.gs_bc_cb;
1137 
1138 	if (!MACHINE_HAS_GS)
1139 		return -ENODEV;
1140 	if (!data)
1141 		return -ENODATA;
1142 	return membuf_write(&to, data, sizeof(struct gs_cb));
1143 }
1144 
1145 static int s390_gs_bc_set(struct task_struct *target,
1146 			  const struct user_regset *regset,
1147 			  unsigned int pos, unsigned int count,
1148 			  const void *kbuf, const void __user *ubuf)
1149 {
1150 	struct gs_cb *data = target->thread.gs_bc_cb;
1151 
1152 	if (!MACHINE_HAS_GS)
1153 		return -ENODEV;
1154 	if (!data) {
1155 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1156 		if (!data)
1157 			return -ENOMEM;
1158 		target->thread.gs_bc_cb = data;
1159 	}
1160 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1161 				  data, 0, sizeof(struct gs_cb));
1162 }
1163 
1164 static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1165 {
1166 	return (cb->rca & 0x1f) == 0 &&
1167 		(cb->roa & 0xfff) == 0 &&
1168 		(cb->rla & 0xfff) == 0xfff &&
1169 		cb->s == 1 &&
1170 		cb->k == 1 &&
1171 		cb->h == 0 &&
1172 		cb->reserved1 == 0 &&
1173 		cb->ps == 1 &&
1174 		cb->qs == 0 &&
1175 		cb->pc == 1 &&
1176 		cb->qc == 0 &&
1177 		cb->reserved2 == 0 &&
1178 		cb->reserved3 == 0 &&
1179 		cb->reserved4 == 0 &&
1180 		cb->reserved5 == 0 &&
1181 		cb->reserved6 == 0 &&
1182 		cb->reserved7 == 0 &&
1183 		cb->reserved8 == 0 &&
1184 		cb->rla >= cb->roa &&
1185 		cb->rca >= cb->roa &&
1186 		cb->rca <= cb->rla+1 &&
1187 		cb->m < 3;
1188 }
1189 
1190 static int s390_runtime_instr_get(struct task_struct *target,
1191 				const struct user_regset *regset,
1192 				struct membuf to)
1193 {
1194 	struct runtime_instr_cb *data = target->thread.ri_cb;
1195 
1196 	if (!test_facility(64))
1197 		return -ENODEV;
1198 	if (!data)
1199 		return -ENODATA;
1200 
1201 	return membuf_write(&to, data, sizeof(struct runtime_instr_cb));
1202 }
1203 
1204 static int s390_runtime_instr_set(struct task_struct *target,
1205 				  const struct user_regset *regset,
1206 				  unsigned int pos, unsigned int count,
1207 				  const void *kbuf, const void __user *ubuf)
1208 {
1209 	struct runtime_instr_cb ri_cb = { }, *data = NULL;
1210 	int rc;
1211 
1212 	if (!test_facility(64))
1213 		return -ENODEV;
1214 
1215 	if (!target->thread.ri_cb) {
1216 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1217 		if (!data)
1218 			return -ENOMEM;
1219 	}
1220 
1221 	if (target->thread.ri_cb) {
1222 		if (target == current)
1223 			store_runtime_instr_cb(&ri_cb);
1224 		else
1225 			ri_cb = *target->thread.ri_cb;
1226 	}
1227 
1228 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1229 				&ri_cb, 0, sizeof(struct runtime_instr_cb));
1230 	if (rc) {
1231 		kfree(data);
1232 		return -EFAULT;
1233 	}
1234 
1235 	if (!is_ri_cb_valid(&ri_cb)) {
1236 		kfree(data);
1237 		return -EINVAL;
1238 	}
1239 	/*
1240 	 * Override access key in any case, since user space should
1241 	 * not be able to set it, nor should it care about it.
1242 	 */
1243 	ri_cb.key = PAGE_DEFAULT_KEY >> 4;
1244 	preempt_disable();
1245 	if (!target->thread.ri_cb)
1246 		target->thread.ri_cb = data;
1247 	*target->thread.ri_cb = ri_cb;
1248 	if (target == current)
1249 		load_runtime_instr_cb(target->thread.ri_cb);
1250 	preempt_enable();
1251 
1252 	return 0;
1253 }
1254 
1255 static const struct user_regset s390_regsets[] = {
1256 	{
1257 		.core_note_type = NT_PRSTATUS,
1258 		.n = sizeof(s390_regs) / sizeof(long),
1259 		.size = sizeof(long),
1260 		.align = sizeof(long),
1261 		.regset_get = s390_regs_get,
1262 		.set = s390_regs_set,
1263 	},
1264 	{
1265 		.core_note_type = NT_PRFPREG,
1266 		.n = sizeof(s390_fp_regs) / sizeof(long),
1267 		.size = sizeof(long),
1268 		.align = sizeof(long),
1269 		.regset_get = s390_fpregs_get,
1270 		.set = s390_fpregs_set,
1271 	},
1272 	{
1273 		.core_note_type = NT_S390_SYSTEM_CALL,
1274 		.n = 1,
1275 		.size = sizeof(unsigned int),
1276 		.align = sizeof(unsigned int),
1277 		.regset_get = s390_system_call_get,
1278 		.set = s390_system_call_set,
1279 	},
1280 	{
1281 		.core_note_type = NT_S390_LAST_BREAK,
1282 		.n = 1,
1283 		.size = sizeof(long),
1284 		.align = sizeof(long),
1285 		.regset_get = s390_last_break_get,
1286 		.set = s390_last_break_set,
1287 	},
1288 	{
1289 		.core_note_type = NT_S390_TDB,
1290 		.n = 1,
1291 		.size = 256,
1292 		.align = 1,
1293 		.regset_get = s390_tdb_get,
1294 		.set = s390_tdb_set,
1295 	},
1296 	{
1297 		.core_note_type = NT_S390_VXRS_LOW,
1298 		.n = __NUM_VXRS_LOW,
1299 		.size = sizeof(__u64),
1300 		.align = sizeof(__u64),
1301 		.regset_get = s390_vxrs_low_get,
1302 		.set = s390_vxrs_low_set,
1303 	},
1304 	{
1305 		.core_note_type = NT_S390_VXRS_HIGH,
1306 		.n = __NUM_VXRS_HIGH,
1307 		.size = sizeof(__vector128),
1308 		.align = sizeof(__vector128),
1309 		.regset_get = s390_vxrs_high_get,
1310 		.set = s390_vxrs_high_set,
1311 	},
1312 	{
1313 		.core_note_type = NT_S390_GS_CB,
1314 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1315 		.size = sizeof(__u64),
1316 		.align = sizeof(__u64),
1317 		.regset_get = s390_gs_cb_get,
1318 		.set = s390_gs_cb_set,
1319 	},
1320 	{
1321 		.core_note_type = NT_S390_GS_BC,
1322 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1323 		.size = sizeof(__u64),
1324 		.align = sizeof(__u64),
1325 		.regset_get = s390_gs_bc_get,
1326 		.set = s390_gs_bc_set,
1327 	},
1328 	{
1329 		.core_note_type = NT_S390_RI_CB,
1330 		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1331 		.size = sizeof(__u64),
1332 		.align = sizeof(__u64),
1333 		.regset_get = s390_runtime_instr_get,
1334 		.set = s390_runtime_instr_set,
1335 	},
1336 };
1337 
1338 static const struct user_regset_view user_s390_view = {
1339 	.name = "s390x",
1340 	.e_machine = EM_S390,
1341 	.regsets = s390_regsets,
1342 	.n = ARRAY_SIZE(s390_regsets)
1343 };
1344 
1345 #ifdef CONFIG_COMPAT
1346 static int s390_compat_regs_get(struct task_struct *target,
1347 				const struct user_regset *regset,
1348 				struct membuf to)
1349 {
1350 	unsigned n;
1351 
1352 	if (target == current)
1353 		save_access_regs(target->thread.acrs);
1354 
1355 	for (n = 0; n < sizeof(s390_compat_regs); n += sizeof(compat_ulong_t))
1356 		membuf_store(&to, __peek_user_compat(target, n));
1357 	return 0;
1358 }
1359 
1360 static int s390_compat_regs_set(struct task_struct *target,
1361 				const struct user_regset *regset,
1362 				unsigned int pos, unsigned int count,
1363 				const void *kbuf, const void __user *ubuf)
1364 {
1365 	int rc = 0;
1366 
1367 	if (target == current)
1368 		save_access_regs(target->thread.acrs);
1369 
1370 	if (kbuf) {
1371 		const compat_ulong_t *k = kbuf;
1372 		while (count > 0 && !rc) {
1373 			rc = __poke_user_compat(target, pos, *k++);
1374 			count -= sizeof(*k);
1375 			pos += sizeof(*k);
1376 		}
1377 	} else {
1378 		const compat_ulong_t  __user *u = ubuf;
1379 		while (count > 0 && !rc) {
1380 			compat_ulong_t word;
1381 			rc = __get_user(word, u++);
1382 			if (rc)
1383 				break;
1384 			rc = __poke_user_compat(target, pos, word);
1385 			count -= sizeof(*u);
1386 			pos += sizeof(*u);
1387 		}
1388 	}
1389 
1390 	if (rc == 0 && target == current)
1391 		restore_access_regs(target->thread.acrs);
1392 
1393 	return rc;
1394 }
1395 
1396 static int s390_compat_regs_high_get(struct task_struct *target,
1397 				     const struct user_regset *regset,
1398 				     struct membuf to)
1399 {
1400 	compat_ulong_t *gprs_high;
1401 	int i;
1402 
1403 	gprs_high = (compat_ulong_t *)task_pt_regs(target)->gprs;
1404 	for (i = 0; i < NUM_GPRS; i++, gprs_high += 2)
1405 		membuf_store(&to, *gprs_high);
1406 	return 0;
1407 }
1408 
1409 static int s390_compat_regs_high_set(struct task_struct *target,
1410 				     const struct user_regset *regset,
1411 				     unsigned int pos, unsigned int count,
1412 				     const void *kbuf, const void __user *ubuf)
1413 {
1414 	compat_ulong_t *gprs_high;
1415 	int rc = 0;
1416 
1417 	gprs_high = (compat_ulong_t *)
1418 		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1419 	if (kbuf) {
1420 		const compat_ulong_t *k = kbuf;
1421 		while (count > 0) {
1422 			*gprs_high = *k++;
1423 			*gprs_high += 2;
1424 			count -= sizeof(*k);
1425 		}
1426 	} else {
1427 		const compat_ulong_t  __user *u = ubuf;
1428 		while (count > 0 && !rc) {
1429 			unsigned long word;
1430 			rc = __get_user(word, u++);
1431 			if (rc)
1432 				break;
1433 			*gprs_high = word;
1434 			*gprs_high += 2;
1435 			count -= sizeof(*u);
1436 		}
1437 	}
1438 
1439 	return rc;
1440 }
1441 
1442 static int s390_compat_last_break_get(struct task_struct *target,
1443 				      const struct user_regset *regset,
1444 				      struct membuf to)
1445 {
1446 	compat_ulong_t last_break = target->thread.last_break;
1447 
1448 	return membuf_store(&to, (unsigned long)last_break);
1449 }
1450 
1451 static int s390_compat_last_break_set(struct task_struct *target,
1452 				      const struct user_regset *regset,
1453 				      unsigned int pos, unsigned int count,
1454 				      const void *kbuf, const void __user *ubuf)
1455 {
1456 	return 0;
1457 }
1458 
1459 static const struct user_regset s390_compat_regsets[] = {
1460 	{
1461 		.core_note_type = NT_PRSTATUS,
1462 		.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1463 		.size = sizeof(compat_long_t),
1464 		.align = sizeof(compat_long_t),
1465 		.regset_get = s390_compat_regs_get,
1466 		.set = s390_compat_regs_set,
1467 	},
1468 	{
1469 		.core_note_type = NT_PRFPREG,
1470 		.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1471 		.size = sizeof(compat_long_t),
1472 		.align = sizeof(compat_long_t),
1473 		.regset_get = s390_fpregs_get,
1474 		.set = s390_fpregs_set,
1475 	},
1476 	{
1477 		.core_note_type = NT_S390_SYSTEM_CALL,
1478 		.n = 1,
1479 		.size = sizeof(compat_uint_t),
1480 		.align = sizeof(compat_uint_t),
1481 		.regset_get = s390_system_call_get,
1482 		.set = s390_system_call_set,
1483 	},
1484 	{
1485 		.core_note_type = NT_S390_LAST_BREAK,
1486 		.n = 1,
1487 		.size = sizeof(long),
1488 		.align = sizeof(long),
1489 		.regset_get = s390_compat_last_break_get,
1490 		.set = s390_compat_last_break_set,
1491 	},
1492 	{
1493 		.core_note_type = NT_S390_TDB,
1494 		.n = 1,
1495 		.size = 256,
1496 		.align = 1,
1497 		.regset_get = s390_tdb_get,
1498 		.set = s390_tdb_set,
1499 	},
1500 	{
1501 		.core_note_type = NT_S390_VXRS_LOW,
1502 		.n = __NUM_VXRS_LOW,
1503 		.size = sizeof(__u64),
1504 		.align = sizeof(__u64),
1505 		.regset_get = s390_vxrs_low_get,
1506 		.set = s390_vxrs_low_set,
1507 	},
1508 	{
1509 		.core_note_type = NT_S390_VXRS_HIGH,
1510 		.n = __NUM_VXRS_HIGH,
1511 		.size = sizeof(__vector128),
1512 		.align = sizeof(__vector128),
1513 		.regset_get = s390_vxrs_high_get,
1514 		.set = s390_vxrs_high_set,
1515 	},
1516 	{
1517 		.core_note_type = NT_S390_HIGH_GPRS,
1518 		.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1519 		.size = sizeof(compat_long_t),
1520 		.align = sizeof(compat_long_t),
1521 		.regset_get = s390_compat_regs_high_get,
1522 		.set = s390_compat_regs_high_set,
1523 	},
1524 	{
1525 		.core_note_type = NT_S390_GS_CB,
1526 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1527 		.size = sizeof(__u64),
1528 		.align = sizeof(__u64),
1529 		.regset_get = s390_gs_cb_get,
1530 		.set = s390_gs_cb_set,
1531 	},
1532 	{
1533 		.core_note_type = NT_S390_GS_BC,
1534 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1535 		.size = sizeof(__u64),
1536 		.align = sizeof(__u64),
1537 		.regset_get = s390_gs_bc_get,
1538 		.set = s390_gs_bc_set,
1539 	},
1540 	{
1541 		.core_note_type = NT_S390_RI_CB,
1542 		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1543 		.size = sizeof(__u64),
1544 		.align = sizeof(__u64),
1545 		.regset_get = s390_runtime_instr_get,
1546 		.set = s390_runtime_instr_set,
1547 	},
1548 };
1549 
1550 static const struct user_regset_view user_s390_compat_view = {
1551 	.name = "s390",
1552 	.e_machine = EM_S390,
1553 	.regsets = s390_compat_regsets,
1554 	.n = ARRAY_SIZE(s390_compat_regsets)
1555 };
1556 #endif
1557 
1558 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1559 {
1560 #ifdef CONFIG_COMPAT
1561 	if (test_tsk_thread_flag(task, TIF_31BIT))
1562 		return &user_s390_compat_view;
1563 #endif
1564 	return &user_s390_view;
1565 }
1566 
1567 static const char *gpr_names[NUM_GPRS] = {
1568 	"r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1569 	"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1570 };
1571 
1572 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1573 {
1574 	if (offset >= NUM_GPRS)
1575 		return 0;
1576 	return regs->gprs[offset];
1577 }
1578 
1579 int regs_query_register_offset(const char *name)
1580 {
1581 	unsigned long offset;
1582 
1583 	if (!name || *name != 'r')
1584 		return -EINVAL;
1585 	if (kstrtoul(name + 1, 10, &offset))
1586 		return -EINVAL;
1587 	if (offset >= NUM_GPRS)
1588 		return -EINVAL;
1589 	return offset;
1590 }
1591 
1592 const char *regs_query_register_name(unsigned int offset)
1593 {
1594 	if (offset >= NUM_GPRS)
1595 		return NULL;
1596 	return gpr_names[offset];
1597 }
1598 
1599 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1600 {
1601 	unsigned long ksp = kernel_stack_pointer(regs);
1602 
1603 	return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1604 }
1605 
1606 /**
1607  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1608  * @regs:pt_regs which contains kernel stack pointer.
1609  * @n:stack entry number.
1610  *
1611  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1612  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1613  * this returns 0.
1614  */
1615 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1616 {
1617 	unsigned long addr;
1618 
1619 	addr = kernel_stack_pointer(regs) + n * sizeof(long);
1620 	if (!regs_within_kernel_stack(regs, addr))
1621 		return 0;
1622 	return *(unsigned long *)addr;
1623 }
1624