xref: /linux/arch/s390/kernel/ptrace.c (revision 300a90b2cb5d442879e6398920c49aebbd5c8e40)
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/seccomp.h>
25 #include <linux/compat.h>
26 #include <trace/syscall.h>
27 #include <asm/guarded_storage.h>
28 #include <asm/access-regs.h>
29 #include <asm/page.h>
30 #include <linux/uaccess.h>
31 #include <asm/unistd.h>
32 #include <asm/runtime_instr.h>
33 #include <asm/facility.h>
34 #include <asm/fpu.h>
35 
36 #include "entry.h"
37 
38 #ifdef CONFIG_COMPAT
39 #include "compat_ptrace.h"
40 #endif
41 
42 void update_cr_regs(struct task_struct *task)
43 {
44 	struct pt_regs *regs = task_pt_regs(task);
45 	struct thread_struct *thread = &task->thread;
46 	union ctlreg0 cr0_old, cr0_new;
47 	union ctlreg2 cr2_old, cr2_new;
48 	int cr0_changed, cr2_changed;
49 	union {
50 		struct ctlreg regs[3];
51 		struct {
52 			struct ctlreg control;
53 			struct ctlreg start;
54 			struct ctlreg end;
55 		};
56 	} old, new;
57 
58 	local_ctl_store(0, &cr0_old.reg);
59 	local_ctl_store(2, &cr2_old.reg);
60 	cr0_new = cr0_old;
61 	cr2_new = cr2_old;
62 	/* Take care of the enable/disable of transactional execution. */
63 	if (MACHINE_HAS_TE) {
64 		/* Set or clear transaction execution TXC bit 8. */
65 		cr0_new.tcx = 1;
66 		if (task->thread.per_flags & PER_FLAG_NO_TE)
67 			cr0_new.tcx = 0;
68 		/* Set or clear transaction execution TDC bits 62 and 63. */
69 		cr2_new.tdc = 0;
70 		if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
71 			if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
72 				cr2_new.tdc = 1;
73 			else
74 				cr2_new.tdc = 2;
75 		}
76 	}
77 	/* Take care of enable/disable of guarded storage. */
78 	if (MACHINE_HAS_GS) {
79 		cr2_new.gse = 0;
80 		if (task->thread.gs_cb)
81 			cr2_new.gse = 1;
82 	}
83 	/* Load control register 0/2 iff changed */
84 	cr0_changed = cr0_new.val != cr0_old.val;
85 	cr2_changed = cr2_new.val != cr2_old.val;
86 	if (cr0_changed)
87 		local_ctl_load(0, &cr0_new.reg);
88 	if (cr2_changed)
89 		local_ctl_load(2, &cr2_new.reg);
90 	/* Copy user specified PER registers */
91 	new.control.val = thread->per_user.control;
92 	new.start.val = thread->per_user.start;
93 	new.end.val = thread->per_user.end;
94 
95 	/* merge TIF_SINGLE_STEP into user specified PER registers. */
96 	if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
97 	    test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
98 		if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
99 			new.control.val |= PER_EVENT_BRANCH;
100 		else
101 			new.control.val |= PER_EVENT_IFETCH;
102 		new.control.val |= PER_CONTROL_SUSPENSION;
103 		new.control.val |= PER_EVENT_TRANSACTION_END;
104 		if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
105 			new.control.val |= PER_EVENT_IFETCH;
106 		new.start.val = 0;
107 		new.end.val = -1UL;
108 	}
109 
110 	/* Take care of the PER enablement bit in the PSW. */
111 	if (!(new.control.val & PER_EVENT_MASK)) {
112 		regs->psw.mask &= ~PSW_MASK_PER;
113 		return;
114 	}
115 	regs->psw.mask |= PSW_MASK_PER;
116 	__local_ctl_store(9, 11, old.regs);
117 	if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
118 		__local_ctl_load(9, 11, new.regs);
119 }
120 
121 void user_enable_single_step(struct task_struct *task)
122 {
123 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
124 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
125 }
126 
127 void user_disable_single_step(struct task_struct *task)
128 {
129 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
130 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
131 }
132 
133 void user_enable_block_step(struct task_struct *task)
134 {
135 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
136 	set_tsk_thread_flag(task, TIF_BLOCK_STEP);
137 }
138 
139 /*
140  * Called by kernel/ptrace.c when detaching..
141  *
142  * Clear all debugging related fields.
143  */
144 void ptrace_disable(struct task_struct *task)
145 {
146 	memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
147 	memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
148 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
149 	clear_tsk_thread_flag(task, TIF_PER_TRAP);
150 	task->thread.per_flags = 0;
151 }
152 
153 #define __ADDR_MASK 7
154 
155 static inline unsigned long __peek_user_per(struct task_struct *child,
156 					    addr_t addr)
157 {
158 	if (addr == offsetof(struct per_struct_kernel, cr9))
159 		/* Control bits of the active per set. */
160 		return test_thread_flag(TIF_SINGLE_STEP) ?
161 			PER_EVENT_IFETCH : child->thread.per_user.control;
162 	else if (addr == offsetof(struct per_struct_kernel, cr10))
163 		/* Start address of the active per set. */
164 		return test_thread_flag(TIF_SINGLE_STEP) ?
165 			0 : child->thread.per_user.start;
166 	else if (addr == offsetof(struct per_struct_kernel, cr11))
167 		/* End address of the active per set. */
168 		return test_thread_flag(TIF_SINGLE_STEP) ?
169 			-1UL : child->thread.per_user.end;
170 	else if (addr == offsetof(struct per_struct_kernel, bits))
171 		/* Single-step bit. */
172 		return test_thread_flag(TIF_SINGLE_STEP) ?
173 			(1UL << (BITS_PER_LONG - 1)) : 0;
174 	else if (addr == offsetof(struct per_struct_kernel, starting_addr))
175 		/* Start address of the user specified per set. */
176 		return child->thread.per_user.start;
177 	else if (addr == offsetof(struct per_struct_kernel, ending_addr))
178 		/* End address of the user specified per set. */
179 		return child->thread.per_user.end;
180 	else if (addr == offsetof(struct per_struct_kernel, perc_atmid))
181 		/* PER code, ATMID and AI of the last PER trap */
182 		return (unsigned long)
183 			child->thread.per_event.cause << (BITS_PER_LONG - 16);
184 	else if (addr == offsetof(struct per_struct_kernel, address))
185 		/* Address of the last PER trap */
186 		return child->thread.per_event.address;
187 	else if (addr == offsetof(struct per_struct_kernel, access_id))
188 		/* Access id of the last PER trap */
189 		return (unsigned long)
190 			child->thread.per_event.paid << (BITS_PER_LONG - 8);
191 	return 0;
192 }
193 
194 /*
195  * Read the word at offset addr from the user area of a process. The
196  * trouble here is that the information is littered over different
197  * locations. The process registers are found on the kernel stack,
198  * the floating point stuff and the trace settings are stored in
199  * the task structure. In addition the different structures in
200  * struct user contain pad bytes that should be read as zeroes.
201  * Lovely...
202  */
203 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
204 {
205 	addr_t offset, tmp;
206 
207 	if (addr < offsetof(struct user, regs.acrs)) {
208 		/*
209 		 * psw and gprs are stored on the stack
210 		 */
211 		tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
212 		if (addr == offsetof(struct user, regs.psw.mask)) {
213 			/* Return a clean psw mask. */
214 			tmp &= PSW_MASK_USER | PSW_MASK_RI;
215 			tmp |= PSW_USER_BITS;
216 		}
217 
218 	} else if (addr < offsetof(struct user, regs.orig_gpr2)) {
219 		/*
220 		 * access registers are stored in the thread structure
221 		 */
222 		offset = addr - offsetof(struct user, regs.acrs);
223 		/*
224 		 * Very special case: old & broken 64 bit gdb reading
225 		 * from acrs[15]. Result is a 64 bit value. Read the
226 		 * 32 bit acrs[15] value and shift it by 32. Sick...
227 		 */
228 		if (addr == offsetof(struct user, regs.acrs[15]))
229 			tmp = ((unsigned long) child->thread.acrs[15]) << 32;
230 		else
231 			tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
232 
233 	} else if (addr == offsetof(struct user, regs.orig_gpr2)) {
234 		/*
235 		 * orig_gpr2 is stored on the kernel stack
236 		 */
237 		tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
238 
239 	} else if (addr < offsetof(struct user, regs.fp_regs)) {
240 		/*
241 		 * prevent reads of padding hole between
242 		 * orig_gpr2 and fp_regs on s390.
243 		 */
244 		tmp = 0;
245 
246 	} else if (addr == offsetof(struct user, regs.fp_regs.fpc)) {
247 		/*
248 		 * floating point control reg. is in the thread structure
249 		 */
250 		tmp = child->thread.ufpu.fpc;
251 		tmp <<= BITS_PER_LONG - 32;
252 
253 	} else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
254 		/*
255 		 * floating point regs. are in the child->thread.ufpu.vxrs array
256 		 */
257 		offset = addr - offsetof(struct user, regs.fp_regs.fprs);
258 		tmp = *(addr_t *)((addr_t)child->thread.ufpu.vxrs + 2 * offset);
259 	} else if (addr < offsetof(struct user, regs.per_info) + sizeof(per_struct)) {
260 		/*
261 		 * Handle access to the per_info structure.
262 		 */
263 		addr -= offsetof(struct user, regs.per_info);
264 		tmp = __peek_user_per(child, addr);
265 
266 	} else
267 		tmp = 0;
268 
269 	return tmp;
270 }
271 
272 static int
273 peek_user(struct task_struct *child, addr_t addr, addr_t data)
274 {
275 	addr_t tmp, mask;
276 
277 	/*
278 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
279 	 * an alignment of 4. Programmers from hell...
280 	 */
281 	mask = __ADDR_MASK;
282 	if (addr >= offsetof(struct user, regs.acrs) &&
283 	    addr < offsetof(struct user, regs.orig_gpr2))
284 		mask = 3;
285 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
286 		return -EIO;
287 
288 	tmp = __peek_user(child, addr);
289 	return put_user(tmp, (addr_t __user *) data);
290 }
291 
292 static inline void __poke_user_per(struct task_struct *child,
293 				   addr_t addr, addr_t data)
294 {
295 	/*
296 	 * There are only three fields in the per_info struct that the
297 	 * debugger user can write to.
298 	 * 1) cr9: the debugger wants to set a new PER event mask
299 	 * 2) starting_addr: the debugger wants to set a new starting
300 	 *    address to use with the PER event mask.
301 	 * 3) ending_addr: the debugger wants to set a new ending
302 	 *    address to use with the PER event mask.
303 	 * The user specified PER event mask and the start and end
304 	 * addresses are used only if single stepping is not in effect.
305 	 * Writes to any other field in per_info are ignored.
306 	 */
307 	if (addr == offsetof(struct per_struct_kernel, cr9))
308 		/* PER event mask of the user specified per set. */
309 		child->thread.per_user.control =
310 			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
311 	else if (addr == offsetof(struct per_struct_kernel, starting_addr))
312 		/* Starting address of the user specified per set. */
313 		child->thread.per_user.start = data;
314 	else if (addr == offsetof(struct per_struct_kernel, ending_addr))
315 		/* Ending address of the user specified per set. */
316 		child->thread.per_user.end = data;
317 }
318 
319 /*
320  * Write a word to the user area of a process at location addr. This
321  * operation does have an additional problem compared to peek_user.
322  * Stores to the program status word and on the floating point
323  * control register needs to get checked for validity.
324  */
325 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
326 {
327 	addr_t offset;
328 
329 
330 	if (addr < offsetof(struct user, regs.acrs)) {
331 		struct pt_regs *regs = task_pt_regs(child);
332 		/*
333 		 * psw and gprs are stored on the stack
334 		 */
335 		if (addr == offsetof(struct user, regs.psw.mask)) {
336 			unsigned long mask = PSW_MASK_USER;
337 
338 			mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
339 			if ((data ^ PSW_USER_BITS) & ~mask)
340 				/* Invalid psw mask. */
341 				return -EINVAL;
342 			if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
343 				/* Invalid address-space-control bits */
344 				return -EINVAL;
345 			if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
346 				/* Invalid addressing mode bits */
347 				return -EINVAL;
348 		}
349 
350 		if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
351 			addr == offsetof(struct user, regs.gprs[2])) {
352 			struct pt_regs *regs = task_pt_regs(child);
353 
354 			regs->int_code = 0x20000 | (data & 0xffff);
355 		}
356 		*(addr_t *)((addr_t) &regs->psw + addr) = data;
357 	} else if (addr < offsetof(struct user, regs.orig_gpr2)) {
358 		/*
359 		 * access registers are stored in the thread structure
360 		 */
361 		offset = addr - offsetof(struct user, regs.acrs);
362 		/*
363 		 * Very special case: old & broken 64 bit gdb writing
364 		 * to acrs[15] with a 64 bit value. Ignore the lower
365 		 * half of the value and write the upper 32 bit to
366 		 * acrs[15]. Sick...
367 		 */
368 		if (addr == offsetof(struct user, regs.acrs[15]))
369 			child->thread.acrs[15] = (unsigned int) (data >> 32);
370 		else
371 			*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
372 
373 	} else if (addr == offsetof(struct user, regs.orig_gpr2)) {
374 		/*
375 		 * orig_gpr2 is stored on the kernel stack
376 		 */
377 		task_pt_regs(child)->orig_gpr2 = data;
378 
379 	} else if (addr < offsetof(struct user, regs.fp_regs)) {
380 		/*
381 		 * prevent writes of padding hole between
382 		 * orig_gpr2 and fp_regs on s390.
383 		 */
384 		return 0;
385 
386 	} else if (addr == offsetof(struct user, regs.fp_regs.fpc)) {
387 		/*
388 		 * floating point control reg. is in the thread structure
389 		 */
390 		if ((unsigned int)data != 0)
391 			return -EINVAL;
392 		child->thread.ufpu.fpc = data >> (BITS_PER_LONG - 32);
393 
394 	} else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
395 		/*
396 		 * floating point regs. are in the child->thread.ufpu.vxrs array
397 		 */
398 		offset = addr - offsetof(struct user, regs.fp_regs.fprs);
399 		*(addr_t *)((addr_t)child->thread.ufpu.vxrs + 2 * offset) = data;
400 	} else if (addr < offsetof(struct user, regs.per_info) + sizeof(per_struct)) {
401 		/*
402 		 * Handle access to the per_info structure.
403 		 */
404 		addr -= offsetof(struct user, regs.per_info);
405 		__poke_user_per(child, addr, data);
406 
407 	}
408 
409 	return 0;
410 }
411 
412 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
413 {
414 	addr_t mask;
415 
416 	/*
417 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
418 	 * an alignment of 4. Programmers from hell indeed...
419 	 */
420 	mask = __ADDR_MASK;
421 	if (addr >= offsetof(struct user, regs.acrs) &&
422 	    addr < offsetof(struct user, regs.orig_gpr2))
423 		mask = 3;
424 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
425 		return -EIO;
426 
427 	return __poke_user(child, addr, data);
428 }
429 
430 long arch_ptrace(struct task_struct *child, long request,
431 		 unsigned long addr, unsigned long data)
432 {
433 	ptrace_area parea;
434 	int copied, ret;
435 
436 	switch (request) {
437 	case PTRACE_PEEKUSR:
438 		/* read the word at location addr in the USER area. */
439 		return peek_user(child, addr, data);
440 
441 	case PTRACE_POKEUSR:
442 		/* write the word at location addr in the USER area */
443 		return poke_user(child, addr, data);
444 
445 	case PTRACE_PEEKUSR_AREA:
446 	case PTRACE_POKEUSR_AREA:
447 		if (copy_from_user(&parea, (void __force __user *) addr,
448 							sizeof(parea)))
449 			return -EFAULT;
450 		addr = parea.kernel_addr;
451 		data = parea.process_addr;
452 		copied = 0;
453 		while (copied < parea.len) {
454 			if (request == PTRACE_PEEKUSR_AREA)
455 				ret = peek_user(child, addr, data);
456 			else {
457 				addr_t utmp;
458 				if (get_user(utmp,
459 					     (addr_t __force __user *) data))
460 					return -EFAULT;
461 				ret = poke_user(child, addr, utmp);
462 			}
463 			if (ret)
464 				return ret;
465 			addr += sizeof(unsigned long);
466 			data += sizeof(unsigned long);
467 			copied += sizeof(unsigned long);
468 		}
469 		return 0;
470 	case PTRACE_GET_LAST_BREAK:
471 		return put_user(child->thread.last_break, (unsigned long __user *)data);
472 	case PTRACE_ENABLE_TE:
473 		if (!MACHINE_HAS_TE)
474 			return -EIO;
475 		child->thread.per_flags &= ~PER_FLAG_NO_TE;
476 		return 0;
477 	case PTRACE_DISABLE_TE:
478 		if (!MACHINE_HAS_TE)
479 			return -EIO;
480 		child->thread.per_flags |= PER_FLAG_NO_TE;
481 		child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
482 		return 0;
483 	case PTRACE_TE_ABORT_RAND:
484 		if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
485 			return -EIO;
486 		switch (data) {
487 		case 0UL:
488 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
489 			break;
490 		case 1UL:
491 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
492 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
493 			break;
494 		case 2UL:
495 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
496 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
497 			break;
498 		default:
499 			return -EINVAL;
500 		}
501 		return 0;
502 	default:
503 		return ptrace_request(child, request, addr, data);
504 	}
505 }
506 
507 #ifdef CONFIG_COMPAT
508 /*
509  * Now the fun part starts... a 31 bit program running in the
510  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
511  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
512  * to handle, the difference to the 64 bit versions of the requests
513  * is that the access is done in multiples of 4 byte instead of
514  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
515  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
516  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
517  * is a 31 bit program too, the content of struct user can be
518  * emulated. A 31 bit program peeking into the struct user of
519  * a 64 bit program is a no-no.
520  */
521 
522 /*
523  * Same as peek_user_per but for a 31 bit program.
524  */
525 static inline __u32 __peek_user_per_compat(struct task_struct *child,
526 					   addr_t addr)
527 {
528 	if (addr == offsetof(struct compat_per_struct_kernel, cr9))
529 		/* Control bits of the active per set. */
530 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
531 			PER_EVENT_IFETCH : child->thread.per_user.control;
532 	else if (addr == offsetof(struct compat_per_struct_kernel, cr10))
533 		/* Start address of the active per set. */
534 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
535 			0 : child->thread.per_user.start;
536 	else if (addr == offsetof(struct compat_per_struct_kernel, cr11))
537 		/* End address of the active per set. */
538 		return test_thread_flag(TIF_SINGLE_STEP) ?
539 			PSW32_ADDR_INSN : child->thread.per_user.end;
540 	else if (addr == offsetof(struct compat_per_struct_kernel, bits))
541 		/* Single-step bit. */
542 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
543 			0x80000000 : 0;
544 	else if (addr == offsetof(struct compat_per_struct_kernel, starting_addr))
545 		/* Start address of the user specified per set. */
546 		return (__u32) child->thread.per_user.start;
547 	else if (addr == offsetof(struct compat_per_struct_kernel, ending_addr))
548 		/* End address of the user specified per set. */
549 		return (__u32) child->thread.per_user.end;
550 	else if (addr == offsetof(struct compat_per_struct_kernel, perc_atmid))
551 		/* PER code, ATMID and AI of the last PER trap */
552 		return (__u32) child->thread.per_event.cause << 16;
553 	else if (addr == offsetof(struct compat_per_struct_kernel, address))
554 		/* Address of the last PER trap */
555 		return (__u32) child->thread.per_event.address;
556 	else if (addr == offsetof(struct compat_per_struct_kernel, access_id))
557 		/* Access id of the last PER trap */
558 		return (__u32) child->thread.per_event.paid << 24;
559 	return 0;
560 }
561 
562 /*
563  * Same as peek_user but for a 31 bit program.
564  */
565 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
566 {
567 	addr_t offset;
568 	__u32 tmp;
569 
570 	if (addr < offsetof(struct compat_user, 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 == offsetof(struct compat_user, 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 == offsetof(struct compat_user, 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 < offsetof(struct compat_user, regs.orig_gpr2)) {
589 		/*
590 		 * access registers are stored in the thread structure
591 		 */
592 		offset = addr - offsetof(struct compat_user, regs.acrs);
593 		tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
594 
595 	} else if (addr == offsetof(struct compat_user, 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 < offsetof(struct compat_user, 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 == offsetof(struct compat_user, regs.fp_regs.fpc)) {
609 		/*
610 		 * floating point control reg. is in the thread structure
611 		 */
612 		tmp = child->thread.ufpu.fpc;
613 
614 	} else if (addr < offsetof(struct compat_user, regs.fp_regs) + sizeof(s390_fp_regs)) {
615 		/*
616 		 * floating point regs. are in the child->thread.ufpu.vxrs array
617 		 */
618 		offset = addr - offsetof(struct compat_user, regs.fp_regs.fprs);
619 		tmp = *(__u32 *)((addr_t)child->thread.ufpu.vxrs + 2 * offset);
620 	} else if (addr < offsetof(struct compat_user, regs.per_info) + sizeof(struct compat_per_struct_kernel)) {
621 		/*
622 		 * Handle access to the per_info structure.
623 		 */
624 		addr -= offsetof(struct compat_user, regs.per_info);
625 		tmp = __peek_user_per_compat(child, addr);
626 
627 	} else
628 		tmp = 0;
629 
630 	return tmp;
631 }
632 
633 static int peek_user_compat(struct task_struct *child,
634 			    addr_t addr, addr_t data)
635 {
636 	__u32 tmp;
637 
638 	if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
639 		return -EIO;
640 
641 	tmp = __peek_user_compat(child, addr);
642 	return put_user(tmp, (__u32 __user *) data);
643 }
644 
645 /*
646  * Same as poke_user_per but for a 31 bit program.
647  */
648 static inline void __poke_user_per_compat(struct task_struct *child,
649 					  addr_t addr, __u32 data)
650 {
651 	if (addr == offsetof(struct compat_per_struct_kernel, cr9))
652 		/* PER event mask of the user specified per set. */
653 		child->thread.per_user.control =
654 			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
655 	else if (addr == offsetof(struct compat_per_struct_kernel, starting_addr))
656 		/* Starting address of the user specified per set. */
657 		child->thread.per_user.start = data;
658 	else if (addr == offsetof(struct compat_per_struct_kernel, ending_addr))
659 		/* Ending address of the user specified per set. */
660 		child->thread.per_user.end = data;
661 }
662 
663 /*
664  * Same as poke_user but for a 31 bit program.
665  */
666 static int __poke_user_compat(struct task_struct *child,
667 			      addr_t addr, addr_t data)
668 {
669 	__u32 tmp = (__u32) data;
670 	addr_t offset;
671 
672 	if (addr < offsetof(struct compat_user, regs.acrs)) {
673 		struct pt_regs *regs = task_pt_regs(child);
674 		/*
675 		 * psw, gprs, acrs and orig_gpr2 are stored on the stack
676 		 */
677 		if (addr == offsetof(struct compat_user, regs.psw.mask)) {
678 			__u32 mask = PSW32_MASK_USER;
679 
680 			mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
681 			/* Build a 64 bit psw mask from 31 bit mask. */
682 			if ((tmp ^ PSW32_USER_BITS) & ~mask)
683 				/* Invalid psw mask. */
684 				return -EINVAL;
685 			if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
686 				/* Invalid address-space-control bits */
687 				return -EINVAL;
688 			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
689 				(regs->psw.mask & PSW_MASK_BA) |
690 				(__u64)(tmp & mask) << 32;
691 		} else if (addr == offsetof(struct compat_user, regs.psw.addr)) {
692 			/* Build a 64 bit psw address from 31 bit address. */
693 			regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
694 			/* Transfer 31 bit amode bit to psw mask. */
695 			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
696 				(__u64)(tmp & PSW32_ADDR_AMODE);
697 		} else {
698 			if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
699 				addr == offsetof(struct compat_user, regs.gprs[2])) {
700 				struct pt_regs *regs = task_pt_regs(child);
701 
702 				regs->int_code = 0x20000 | (data & 0xffff);
703 			}
704 			/* gpr 0-15 */
705 			*(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
706 		}
707 	} else if (addr < offsetof(struct compat_user, regs.orig_gpr2)) {
708 		/*
709 		 * access registers are stored in the thread structure
710 		 */
711 		offset = addr - offsetof(struct compat_user, regs.acrs);
712 		*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
713 
714 	} else if (addr == offsetof(struct compat_user, regs.orig_gpr2)) {
715 		/*
716 		 * orig_gpr2 is stored on the kernel stack
717 		 */
718 		*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
719 
720 	} else if (addr < offsetof(struct compat_user, regs.fp_regs)) {
721 		/*
722 		 * prevent writess of padding hole between
723 		 * orig_gpr2 and fp_regs on s390.
724 		 */
725 		return 0;
726 
727 	} else if (addr == offsetof(struct compat_user, regs.fp_regs.fpc)) {
728 		/*
729 		 * floating point control reg. is in the thread structure
730 		 */
731 		child->thread.ufpu.fpc = data;
732 
733 	} else if (addr < offsetof(struct compat_user, regs.fp_regs) + sizeof(s390_fp_regs)) {
734 		/*
735 		 * floating point regs. are in the child->thread.ufpu.vxrs array
736 		 */
737 		offset = addr - offsetof(struct compat_user, regs.fp_regs.fprs);
738 		*(__u32 *)((addr_t)child->thread.ufpu.vxrs + 2 * offset) = tmp;
739 	} else if (addr < offsetof(struct compat_user, regs.per_info) + sizeof(struct compat_per_struct_kernel)) {
740 		/*
741 		 * Handle access to the per_info structure.
742 		 */
743 		addr -= offsetof(struct compat_user, regs.per_info);
744 		__poke_user_per_compat(child, addr, data);
745 	}
746 
747 	return 0;
748 }
749 
750 static int poke_user_compat(struct task_struct *child,
751 			    addr_t addr, addr_t data)
752 {
753 	if (!is_compat_task() || (addr & 3) ||
754 	    addr > sizeof(struct compat_user) - 3)
755 		return -EIO;
756 
757 	return __poke_user_compat(child, addr, data);
758 }
759 
760 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
761 			compat_ulong_t caddr, compat_ulong_t cdata)
762 {
763 	unsigned long addr = caddr;
764 	unsigned long data = cdata;
765 	compat_ptrace_area parea;
766 	int copied, ret;
767 
768 	switch (request) {
769 	case PTRACE_PEEKUSR:
770 		/* read the word at location addr in the USER area. */
771 		return peek_user_compat(child, addr, data);
772 
773 	case PTRACE_POKEUSR:
774 		/* write the word at location addr in the USER area */
775 		return poke_user_compat(child, addr, data);
776 
777 	case PTRACE_PEEKUSR_AREA:
778 	case PTRACE_POKEUSR_AREA:
779 		if (copy_from_user(&parea, (void __force __user *) addr,
780 							sizeof(parea)))
781 			return -EFAULT;
782 		addr = parea.kernel_addr;
783 		data = parea.process_addr;
784 		copied = 0;
785 		while (copied < parea.len) {
786 			if (request == PTRACE_PEEKUSR_AREA)
787 				ret = peek_user_compat(child, addr, data);
788 			else {
789 				__u32 utmp;
790 				if (get_user(utmp,
791 					     (__u32 __force __user *) data))
792 					return -EFAULT;
793 				ret = poke_user_compat(child, addr, utmp);
794 			}
795 			if (ret)
796 				return ret;
797 			addr += sizeof(unsigned int);
798 			data += sizeof(unsigned int);
799 			copied += sizeof(unsigned int);
800 		}
801 		return 0;
802 	case PTRACE_GET_LAST_BREAK:
803 		return put_user(child->thread.last_break, (unsigned int __user *)data);
804 	}
805 	return compat_ptrace_request(child, request, addr, data);
806 }
807 #endif
808 
809 /*
810  * user_regset definitions.
811  */
812 
813 static int s390_regs_get(struct task_struct *target,
814 			 const struct user_regset *regset,
815 			 struct membuf to)
816 {
817 	unsigned pos;
818 	if (target == current)
819 		save_access_regs(target->thread.acrs);
820 
821 	for (pos = 0; pos < sizeof(s390_regs); pos += sizeof(long))
822 		membuf_store(&to, __peek_user(target, pos));
823 	return 0;
824 }
825 
826 static int s390_regs_set(struct task_struct *target,
827 			 const struct user_regset *regset,
828 			 unsigned int pos, unsigned int count,
829 			 const void *kbuf, const void __user *ubuf)
830 {
831 	int rc = 0;
832 
833 	if (target == current)
834 		save_access_regs(target->thread.acrs);
835 
836 	if (kbuf) {
837 		const unsigned long *k = kbuf;
838 		while (count > 0 && !rc) {
839 			rc = __poke_user(target, pos, *k++);
840 			count -= sizeof(*k);
841 			pos += sizeof(*k);
842 		}
843 	} else {
844 		const unsigned long  __user *u = ubuf;
845 		while (count > 0 && !rc) {
846 			unsigned long word;
847 			rc = __get_user(word, u++);
848 			if (rc)
849 				break;
850 			rc = __poke_user(target, pos, word);
851 			count -= sizeof(*u);
852 			pos += sizeof(*u);
853 		}
854 	}
855 
856 	if (rc == 0 && target == current)
857 		restore_access_regs(target->thread.acrs);
858 
859 	return rc;
860 }
861 
862 static int s390_fpregs_get(struct task_struct *target,
863 			   const struct user_regset *regset,
864 			   struct membuf to)
865 {
866 	_s390_fp_regs fp_regs;
867 
868 	if (target == current)
869 		save_user_fpu_regs();
870 
871 	fp_regs.fpc = target->thread.ufpu.fpc;
872 	fpregs_store(&fp_regs, &target->thread.ufpu);
873 
874 	return membuf_write(&to, &fp_regs, sizeof(fp_regs));
875 }
876 
877 static int s390_fpregs_set(struct task_struct *target,
878 			   const struct user_regset *regset, unsigned int pos,
879 			   unsigned int count, const void *kbuf,
880 			   const void __user *ubuf)
881 {
882 	int rc = 0;
883 	freg_t fprs[__NUM_FPRS];
884 
885 	if (target == current)
886 		save_user_fpu_regs();
887 	convert_vx_to_fp(fprs, target->thread.ufpu.vxrs);
888 	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
889 		u32 ufpc[2] = { target->thread.ufpu.fpc, 0 };
890 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
891 					0, offsetof(s390_fp_regs, fprs));
892 		if (rc)
893 			return rc;
894 		if (ufpc[1] != 0)
895 			return -EINVAL;
896 		target->thread.ufpu.fpc = ufpc[0];
897 	}
898 
899 	if (rc == 0 && count > 0)
900 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
901 					fprs, offsetof(s390_fp_regs, fprs), -1);
902 	if (rc)
903 		return rc;
904 	convert_fp_to_vx(target->thread.ufpu.vxrs, fprs);
905 	return rc;
906 }
907 
908 static int s390_last_break_get(struct task_struct *target,
909 			       const struct user_regset *regset,
910 			       struct membuf to)
911 {
912 	return membuf_store(&to, target->thread.last_break);
913 }
914 
915 static int s390_last_break_set(struct task_struct *target,
916 			       const struct user_regset *regset,
917 			       unsigned int pos, unsigned int count,
918 			       const void *kbuf, const void __user *ubuf)
919 {
920 	return 0;
921 }
922 
923 static int s390_tdb_get(struct task_struct *target,
924 			const struct user_regset *regset,
925 			struct membuf to)
926 {
927 	struct pt_regs *regs = task_pt_regs(target);
928 	size_t size;
929 
930 	if (!(regs->int_code & 0x200))
931 		return -ENODATA;
932 	size = sizeof(target->thread.trap_tdb.data);
933 	return membuf_write(&to, target->thread.trap_tdb.data, size);
934 }
935 
936 static int s390_tdb_set(struct task_struct *target,
937 			const struct user_regset *regset,
938 			unsigned int pos, unsigned int count,
939 			const void *kbuf, const void __user *ubuf)
940 {
941 	return 0;
942 }
943 
944 static int s390_vxrs_low_get(struct task_struct *target,
945 			     const struct user_regset *regset,
946 			     struct membuf to)
947 {
948 	__u64 vxrs[__NUM_VXRS_LOW];
949 	int i;
950 
951 	if (!cpu_has_vx())
952 		return -ENODEV;
953 	if (target == current)
954 		save_user_fpu_regs();
955 	for (i = 0; i < __NUM_VXRS_LOW; i++)
956 		vxrs[i] = target->thread.ufpu.vxrs[i].low;
957 	return membuf_write(&to, vxrs, sizeof(vxrs));
958 }
959 
960 static int s390_vxrs_low_set(struct task_struct *target,
961 			     const struct user_regset *regset,
962 			     unsigned int pos, unsigned int count,
963 			     const void *kbuf, const void __user *ubuf)
964 {
965 	__u64 vxrs[__NUM_VXRS_LOW];
966 	int i, rc;
967 
968 	if (!cpu_has_vx())
969 		return -ENODEV;
970 	if (target == current)
971 		save_user_fpu_regs();
972 
973 	for (i = 0; i < __NUM_VXRS_LOW; i++)
974 		vxrs[i] = target->thread.ufpu.vxrs[i].low;
975 
976 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
977 	if (rc == 0)
978 		for (i = 0; i < __NUM_VXRS_LOW; i++)
979 			target->thread.ufpu.vxrs[i].low = vxrs[i];
980 
981 	return rc;
982 }
983 
984 static int s390_vxrs_high_get(struct task_struct *target,
985 			      const struct user_regset *regset,
986 			      struct membuf to)
987 {
988 	if (!cpu_has_vx())
989 		return -ENODEV;
990 	if (target == current)
991 		save_user_fpu_regs();
992 	return membuf_write(&to, target->thread.ufpu.vxrs + __NUM_VXRS_LOW,
993 			    __NUM_VXRS_HIGH * sizeof(__vector128));
994 }
995 
996 static int s390_vxrs_high_set(struct task_struct *target,
997 			      const struct user_regset *regset,
998 			      unsigned int pos, unsigned int count,
999 			      const void *kbuf, const void __user *ubuf)
1000 {
1001 	int rc;
1002 
1003 	if (!cpu_has_vx())
1004 		return -ENODEV;
1005 	if (target == current)
1006 		save_user_fpu_regs();
1007 
1008 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1009 				target->thread.ufpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1010 	return rc;
1011 }
1012 
1013 static int s390_system_call_get(struct task_struct *target,
1014 				const struct user_regset *regset,
1015 				struct membuf to)
1016 {
1017 	return membuf_store(&to, target->thread.system_call);
1018 }
1019 
1020 static int s390_system_call_set(struct task_struct *target,
1021 				const struct user_regset *regset,
1022 				unsigned int pos, unsigned int count,
1023 				const void *kbuf, const void __user *ubuf)
1024 {
1025 	unsigned int *data = &target->thread.system_call;
1026 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1027 				  data, 0, sizeof(unsigned int));
1028 }
1029 
1030 static int s390_gs_cb_get(struct task_struct *target,
1031 			  const struct user_regset *regset,
1032 			  struct membuf to)
1033 {
1034 	struct gs_cb *data = target->thread.gs_cb;
1035 
1036 	if (!MACHINE_HAS_GS)
1037 		return -ENODEV;
1038 	if (!data)
1039 		return -ENODATA;
1040 	if (target == current)
1041 		save_gs_cb(data);
1042 	return membuf_write(&to, data, sizeof(struct gs_cb));
1043 }
1044 
1045 static int s390_gs_cb_set(struct task_struct *target,
1046 			  const struct user_regset *regset,
1047 			  unsigned int pos, unsigned int count,
1048 			  const void *kbuf, const void __user *ubuf)
1049 {
1050 	struct gs_cb gs_cb = { }, *data = NULL;
1051 	int rc;
1052 
1053 	if (!MACHINE_HAS_GS)
1054 		return -ENODEV;
1055 	if (!target->thread.gs_cb) {
1056 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1057 		if (!data)
1058 			return -ENOMEM;
1059 	}
1060 	if (!target->thread.gs_cb)
1061 		gs_cb.gsd = 25;
1062 	else if (target == current)
1063 		save_gs_cb(&gs_cb);
1064 	else
1065 		gs_cb = *target->thread.gs_cb;
1066 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1067 				&gs_cb, 0, sizeof(gs_cb));
1068 	if (rc) {
1069 		kfree(data);
1070 		return -EFAULT;
1071 	}
1072 	preempt_disable();
1073 	if (!target->thread.gs_cb)
1074 		target->thread.gs_cb = data;
1075 	*target->thread.gs_cb = gs_cb;
1076 	if (target == current) {
1077 		local_ctl_set_bit(2, CR2_GUARDED_STORAGE_BIT);
1078 		restore_gs_cb(target->thread.gs_cb);
1079 	}
1080 	preempt_enable();
1081 	return rc;
1082 }
1083 
1084 static int s390_gs_bc_get(struct task_struct *target,
1085 			  const struct user_regset *regset,
1086 			  struct membuf to)
1087 {
1088 	struct gs_cb *data = target->thread.gs_bc_cb;
1089 
1090 	if (!MACHINE_HAS_GS)
1091 		return -ENODEV;
1092 	if (!data)
1093 		return -ENODATA;
1094 	return membuf_write(&to, data, sizeof(struct gs_cb));
1095 }
1096 
1097 static int s390_gs_bc_set(struct task_struct *target,
1098 			  const struct user_regset *regset,
1099 			  unsigned int pos, unsigned int count,
1100 			  const void *kbuf, const void __user *ubuf)
1101 {
1102 	struct gs_cb *data = target->thread.gs_bc_cb;
1103 
1104 	if (!MACHINE_HAS_GS)
1105 		return -ENODEV;
1106 	if (!data) {
1107 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1108 		if (!data)
1109 			return -ENOMEM;
1110 		target->thread.gs_bc_cb = data;
1111 	}
1112 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1113 				  data, 0, sizeof(struct gs_cb));
1114 }
1115 
1116 static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1117 {
1118 	return (cb->rca & 0x1f) == 0 &&
1119 		(cb->roa & 0xfff) == 0 &&
1120 		(cb->rla & 0xfff) == 0xfff &&
1121 		cb->s == 1 &&
1122 		cb->k == 1 &&
1123 		cb->h == 0 &&
1124 		cb->reserved1 == 0 &&
1125 		cb->ps == 1 &&
1126 		cb->qs == 0 &&
1127 		cb->pc == 1 &&
1128 		cb->qc == 0 &&
1129 		cb->reserved2 == 0 &&
1130 		cb->reserved3 == 0 &&
1131 		cb->reserved4 == 0 &&
1132 		cb->reserved5 == 0 &&
1133 		cb->reserved6 == 0 &&
1134 		cb->reserved7 == 0 &&
1135 		cb->reserved8 == 0 &&
1136 		cb->rla >= cb->roa &&
1137 		cb->rca >= cb->roa &&
1138 		cb->rca <= cb->rla+1 &&
1139 		cb->m < 3;
1140 }
1141 
1142 static int s390_runtime_instr_get(struct task_struct *target,
1143 				const struct user_regset *regset,
1144 				struct membuf to)
1145 {
1146 	struct runtime_instr_cb *data = target->thread.ri_cb;
1147 
1148 	if (!test_facility(64))
1149 		return -ENODEV;
1150 	if (!data)
1151 		return -ENODATA;
1152 
1153 	return membuf_write(&to, data, sizeof(struct runtime_instr_cb));
1154 }
1155 
1156 static int s390_runtime_instr_set(struct task_struct *target,
1157 				  const struct user_regset *regset,
1158 				  unsigned int pos, unsigned int count,
1159 				  const void *kbuf, const void __user *ubuf)
1160 {
1161 	struct runtime_instr_cb ri_cb = { }, *data = NULL;
1162 	int rc;
1163 
1164 	if (!test_facility(64))
1165 		return -ENODEV;
1166 
1167 	if (!target->thread.ri_cb) {
1168 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1169 		if (!data)
1170 			return -ENOMEM;
1171 	}
1172 
1173 	if (target->thread.ri_cb) {
1174 		if (target == current)
1175 			store_runtime_instr_cb(&ri_cb);
1176 		else
1177 			ri_cb = *target->thread.ri_cb;
1178 	}
1179 
1180 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1181 				&ri_cb, 0, sizeof(struct runtime_instr_cb));
1182 	if (rc) {
1183 		kfree(data);
1184 		return -EFAULT;
1185 	}
1186 
1187 	if (!is_ri_cb_valid(&ri_cb)) {
1188 		kfree(data);
1189 		return -EINVAL;
1190 	}
1191 	/*
1192 	 * Override access key in any case, since user space should
1193 	 * not be able to set it, nor should it care about it.
1194 	 */
1195 	ri_cb.key = PAGE_DEFAULT_KEY >> 4;
1196 	preempt_disable();
1197 	if (!target->thread.ri_cb)
1198 		target->thread.ri_cb = data;
1199 	*target->thread.ri_cb = ri_cb;
1200 	if (target == current)
1201 		load_runtime_instr_cb(target->thread.ri_cb);
1202 	preempt_enable();
1203 
1204 	return 0;
1205 }
1206 
1207 static const struct user_regset s390_regsets[] = {
1208 	{
1209 		.core_note_type = NT_PRSTATUS,
1210 		.n = sizeof(s390_regs) / sizeof(long),
1211 		.size = sizeof(long),
1212 		.align = sizeof(long),
1213 		.regset_get = s390_regs_get,
1214 		.set = s390_regs_set,
1215 	},
1216 	{
1217 		.core_note_type = NT_PRFPREG,
1218 		.n = sizeof(s390_fp_regs) / sizeof(long),
1219 		.size = sizeof(long),
1220 		.align = sizeof(long),
1221 		.regset_get = s390_fpregs_get,
1222 		.set = s390_fpregs_set,
1223 	},
1224 	{
1225 		.core_note_type = NT_S390_SYSTEM_CALL,
1226 		.n = 1,
1227 		.size = sizeof(unsigned int),
1228 		.align = sizeof(unsigned int),
1229 		.regset_get = s390_system_call_get,
1230 		.set = s390_system_call_set,
1231 	},
1232 	{
1233 		.core_note_type = NT_S390_LAST_BREAK,
1234 		.n = 1,
1235 		.size = sizeof(long),
1236 		.align = sizeof(long),
1237 		.regset_get = s390_last_break_get,
1238 		.set = s390_last_break_set,
1239 	},
1240 	{
1241 		.core_note_type = NT_S390_TDB,
1242 		.n = 1,
1243 		.size = 256,
1244 		.align = 1,
1245 		.regset_get = s390_tdb_get,
1246 		.set = s390_tdb_set,
1247 	},
1248 	{
1249 		.core_note_type = NT_S390_VXRS_LOW,
1250 		.n = __NUM_VXRS_LOW,
1251 		.size = sizeof(__u64),
1252 		.align = sizeof(__u64),
1253 		.regset_get = s390_vxrs_low_get,
1254 		.set = s390_vxrs_low_set,
1255 	},
1256 	{
1257 		.core_note_type = NT_S390_VXRS_HIGH,
1258 		.n = __NUM_VXRS_HIGH,
1259 		.size = sizeof(__vector128),
1260 		.align = sizeof(__vector128),
1261 		.regset_get = s390_vxrs_high_get,
1262 		.set = s390_vxrs_high_set,
1263 	},
1264 	{
1265 		.core_note_type = NT_S390_GS_CB,
1266 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1267 		.size = sizeof(__u64),
1268 		.align = sizeof(__u64),
1269 		.regset_get = s390_gs_cb_get,
1270 		.set = s390_gs_cb_set,
1271 	},
1272 	{
1273 		.core_note_type = NT_S390_GS_BC,
1274 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1275 		.size = sizeof(__u64),
1276 		.align = sizeof(__u64),
1277 		.regset_get = s390_gs_bc_get,
1278 		.set = s390_gs_bc_set,
1279 	},
1280 	{
1281 		.core_note_type = NT_S390_RI_CB,
1282 		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1283 		.size = sizeof(__u64),
1284 		.align = sizeof(__u64),
1285 		.regset_get = s390_runtime_instr_get,
1286 		.set = s390_runtime_instr_set,
1287 	},
1288 };
1289 
1290 static const struct user_regset_view user_s390_view = {
1291 	.name = "s390x",
1292 	.e_machine = EM_S390,
1293 	.regsets = s390_regsets,
1294 	.n = ARRAY_SIZE(s390_regsets)
1295 };
1296 
1297 #ifdef CONFIG_COMPAT
1298 static int s390_compat_regs_get(struct task_struct *target,
1299 				const struct user_regset *regset,
1300 				struct membuf to)
1301 {
1302 	unsigned n;
1303 
1304 	if (target == current)
1305 		save_access_regs(target->thread.acrs);
1306 
1307 	for (n = 0; n < sizeof(s390_compat_regs); n += sizeof(compat_ulong_t))
1308 		membuf_store(&to, __peek_user_compat(target, n));
1309 	return 0;
1310 }
1311 
1312 static int s390_compat_regs_set(struct task_struct *target,
1313 				const struct user_regset *regset,
1314 				unsigned int pos, unsigned int count,
1315 				const void *kbuf, const void __user *ubuf)
1316 {
1317 	int rc = 0;
1318 
1319 	if (target == current)
1320 		save_access_regs(target->thread.acrs);
1321 
1322 	if (kbuf) {
1323 		const compat_ulong_t *k = kbuf;
1324 		while (count > 0 && !rc) {
1325 			rc = __poke_user_compat(target, pos, *k++);
1326 			count -= sizeof(*k);
1327 			pos += sizeof(*k);
1328 		}
1329 	} else {
1330 		const compat_ulong_t  __user *u = ubuf;
1331 		while (count > 0 && !rc) {
1332 			compat_ulong_t word;
1333 			rc = __get_user(word, u++);
1334 			if (rc)
1335 				break;
1336 			rc = __poke_user_compat(target, pos, word);
1337 			count -= sizeof(*u);
1338 			pos += sizeof(*u);
1339 		}
1340 	}
1341 
1342 	if (rc == 0 && target == current)
1343 		restore_access_regs(target->thread.acrs);
1344 
1345 	return rc;
1346 }
1347 
1348 static int s390_compat_regs_high_get(struct task_struct *target,
1349 				     const struct user_regset *regset,
1350 				     struct membuf to)
1351 {
1352 	compat_ulong_t *gprs_high;
1353 	int i;
1354 
1355 	gprs_high = (compat_ulong_t *)task_pt_regs(target)->gprs;
1356 	for (i = 0; i < NUM_GPRS; i++, gprs_high += 2)
1357 		membuf_store(&to, *gprs_high);
1358 	return 0;
1359 }
1360 
1361 static int s390_compat_regs_high_set(struct task_struct *target,
1362 				     const struct user_regset *regset,
1363 				     unsigned int pos, unsigned int count,
1364 				     const void *kbuf, const void __user *ubuf)
1365 {
1366 	compat_ulong_t *gprs_high;
1367 	int rc = 0;
1368 
1369 	gprs_high = (compat_ulong_t *)
1370 		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1371 	if (kbuf) {
1372 		const compat_ulong_t *k = kbuf;
1373 		while (count > 0) {
1374 			*gprs_high = *k++;
1375 			*gprs_high += 2;
1376 			count -= sizeof(*k);
1377 		}
1378 	} else {
1379 		const compat_ulong_t  __user *u = ubuf;
1380 		while (count > 0 && !rc) {
1381 			unsigned long word;
1382 			rc = __get_user(word, u++);
1383 			if (rc)
1384 				break;
1385 			*gprs_high = word;
1386 			*gprs_high += 2;
1387 			count -= sizeof(*u);
1388 		}
1389 	}
1390 
1391 	return rc;
1392 }
1393 
1394 static int s390_compat_last_break_get(struct task_struct *target,
1395 				      const struct user_regset *regset,
1396 				      struct membuf to)
1397 {
1398 	compat_ulong_t last_break = target->thread.last_break;
1399 
1400 	return membuf_store(&to, (unsigned long)last_break);
1401 }
1402 
1403 static int s390_compat_last_break_set(struct task_struct *target,
1404 				      const struct user_regset *regset,
1405 				      unsigned int pos, unsigned int count,
1406 				      const void *kbuf, const void __user *ubuf)
1407 {
1408 	return 0;
1409 }
1410 
1411 static const struct user_regset s390_compat_regsets[] = {
1412 	{
1413 		.core_note_type = NT_PRSTATUS,
1414 		.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1415 		.size = sizeof(compat_long_t),
1416 		.align = sizeof(compat_long_t),
1417 		.regset_get = s390_compat_regs_get,
1418 		.set = s390_compat_regs_set,
1419 	},
1420 	{
1421 		.core_note_type = NT_PRFPREG,
1422 		.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1423 		.size = sizeof(compat_long_t),
1424 		.align = sizeof(compat_long_t),
1425 		.regset_get = s390_fpregs_get,
1426 		.set = s390_fpregs_set,
1427 	},
1428 	{
1429 		.core_note_type = NT_S390_SYSTEM_CALL,
1430 		.n = 1,
1431 		.size = sizeof(compat_uint_t),
1432 		.align = sizeof(compat_uint_t),
1433 		.regset_get = s390_system_call_get,
1434 		.set = s390_system_call_set,
1435 	},
1436 	{
1437 		.core_note_type = NT_S390_LAST_BREAK,
1438 		.n = 1,
1439 		.size = sizeof(long),
1440 		.align = sizeof(long),
1441 		.regset_get = s390_compat_last_break_get,
1442 		.set = s390_compat_last_break_set,
1443 	},
1444 	{
1445 		.core_note_type = NT_S390_TDB,
1446 		.n = 1,
1447 		.size = 256,
1448 		.align = 1,
1449 		.regset_get = s390_tdb_get,
1450 		.set = s390_tdb_set,
1451 	},
1452 	{
1453 		.core_note_type = NT_S390_VXRS_LOW,
1454 		.n = __NUM_VXRS_LOW,
1455 		.size = sizeof(__u64),
1456 		.align = sizeof(__u64),
1457 		.regset_get = s390_vxrs_low_get,
1458 		.set = s390_vxrs_low_set,
1459 	},
1460 	{
1461 		.core_note_type = NT_S390_VXRS_HIGH,
1462 		.n = __NUM_VXRS_HIGH,
1463 		.size = sizeof(__vector128),
1464 		.align = sizeof(__vector128),
1465 		.regset_get = s390_vxrs_high_get,
1466 		.set = s390_vxrs_high_set,
1467 	},
1468 	{
1469 		.core_note_type = NT_S390_HIGH_GPRS,
1470 		.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1471 		.size = sizeof(compat_long_t),
1472 		.align = sizeof(compat_long_t),
1473 		.regset_get = s390_compat_regs_high_get,
1474 		.set = s390_compat_regs_high_set,
1475 	},
1476 	{
1477 		.core_note_type = NT_S390_GS_CB,
1478 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1479 		.size = sizeof(__u64),
1480 		.align = sizeof(__u64),
1481 		.regset_get = s390_gs_cb_get,
1482 		.set = s390_gs_cb_set,
1483 	},
1484 	{
1485 		.core_note_type = NT_S390_GS_BC,
1486 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1487 		.size = sizeof(__u64),
1488 		.align = sizeof(__u64),
1489 		.regset_get = s390_gs_bc_get,
1490 		.set = s390_gs_bc_set,
1491 	},
1492 	{
1493 		.core_note_type = NT_S390_RI_CB,
1494 		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1495 		.size = sizeof(__u64),
1496 		.align = sizeof(__u64),
1497 		.regset_get = s390_runtime_instr_get,
1498 		.set = s390_runtime_instr_set,
1499 	},
1500 };
1501 
1502 static const struct user_regset_view user_s390_compat_view = {
1503 	.name = "s390",
1504 	.e_machine = EM_S390,
1505 	.regsets = s390_compat_regsets,
1506 	.n = ARRAY_SIZE(s390_compat_regsets)
1507 };
1508 #endif
1509 
1510 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1511 {
1512 #ifdef CONFIG_COMPAT
1513 	if (test_tsk_thread_flag(task, TIF_31BIT))
1514 		return &user_s390_compat_view;
1515 #endif
1516 	return &user_s390_view;
1517 }
1518 
1519 static const char *gpr_names[NUM_GPRS] = {
1520 	"r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1521 	"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1522 };
1523 
1524 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1525 {
1526 	if (offset >= NUM_GPRS)
1527 		return 0;
1528 	return regs->gprs[offset];
1529 }
1530 
1531 int regs_query_register_offset(const char *name)
1532 {
1533 	unsigned long offset;
1534 
1535 	if (!name || *name != 'r')
1536 		return -EINVAL;
1537 	if (kstrtoul(name + 1, 10, &offset))
1538 		return -EINVAL;
1539 	if (offset >= NUM_GPRS)
1540 		return -EINVAL;
1541 	return offset;
1542 }
1543 
1544 const char *regs_query_register_name(unsigned int offset)
1545 {
1546 	if (offset >= NUM_GPRS)
1547 		return NULL;
1548 	return gpr_names[offset];
1549 }
1550 
1551 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1552 {
1553 	unsigned long ksp = kernel_stack_pointer(regs);
1554 
1555 	return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1556 }
1557 
1558 /**
1559  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1560  * @regs:pt_regs which contains kernel stack pointer.
1561  * @n:stack entry number.
1562  *
1563  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1564  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1565  * this returns 0.
1566  */
1567 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1568 {
1569 	unsigned long addr;
1570 
1571 	addr = kernel_stack_pointer(regs) + n * sizeof(long);
1572 	if (!regs_within_kernel_stack(regs, addr))
1573 		return 0;
1574 	return *(unsigned long *)addr;
1575 }
1576