xref: /openbmc/linux/arch/s390/kernel/ptrace.c (revision f9834f18)
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 <linux/kernel.h>
11 #include <linux/sched.h>
12 #include <linux/sched/task_stack.h>
13 #include <linux/mm.h>
14 #include <linux/smp.h>
15 #include <linux/errno.h>
16 #include <linux/ptrace.h>
17 #include <linux/user.h>
18 #include <linux/security.h>
19 #include <linux/audit.h>
20 #include <linux/signal.h>
21 #include <linux/elf.h>
22 #include <linux/regset.h>
23 #include <linux/tracehook.h>
24 #include <linux/seccomp.h>
25 #include <linux/compat.h>
26 #include <trace/syscall.h>
27 #include <asm/page.h>
28 #include <asm/pgtable.h>
29 #include <asm/pgalloc.h>
30 #include <linux/uaccess.h>
31 #include <asm/unistd.h>
32 #include <asm/switch_to.h>
33 #include <asm/runtime_instr.h>
34 #include <asm/facility.h>
35 
36 #include "entry.h"
37 
38 #ifdef CONFIG_COMPAT
39 #include "compat_ptrace.h"
40 #endif
41 
42 #define CREATE_TRACE_POINTS
43 #include <trace/events/syscalls.h>
44 
45 void update_cr_regs(struct task_struct *task)
46 {
47 	struct pt_regs *regs = task_pt_regs(task);
48 	struct thread_struct *thread = &task->thread;
49 	struct per_regs old, new;
50 	union ctlreg0 cr0_old, cr0_new;
51 	union ctlreg2 cr2_old, cr2_new;
52 	int cr0_changed, cr2_changed;
53 
54 	__ctl_store(cr0_old.val, 0, 0);
55 	__ctl_store(cr2_old.val, 2, 2);
56 	cr0_new = cr0_old;
57 	cr2_new = cr2_old;
58 	/* Take care of the enable/disable of transactional execution. */
59 	if (MACHINE_HAS_TE) {
60 		/* Set or clear transaction execution TXC bit 8. */
61 		cr0_new.tcx = 1;
62 		if (task->thread.per_flags & PER_FLAG_NO_TE)
63 			cr0_new.tcx = 0;
64 		/* Set or clear transaction execution TDC bits 62 and 63. */
65 		cr2_new.tdc = 0;
66 		if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
67 			if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
68 				cr2_new.tdc = 1;
69 			else
70 				cr2_new.tdc = 2;
71 		}
72 	}
73 	/* Take care of enable/disable of guarded storage. */
74 	if (MACHINE_HAS_GS) {
75 		cr2_new.gse = 0;
76 		if (task->thread.gs_cb)
77 			cr2_new.gse = 1;
78 	}
79 	/* Load control register 0/2 iff changed */
80 	cr0_changed = cr0_new.val != cr0_old.val;
81 	cr2_changed = cr2_new.val != cr2_old.val;
82 	if (cr0_changed)
83 		__ctl_load(cr0_new.val, 0, 0);
84 	if (cr2_changed)
85 		__ctl_load(cr2_new.val, 2, 2);
86 	/* Copy user specified PER registers */
87 	new.control = thread->per_user.control;
88 	new.start = thread->per_user.start;
89 	new.end = thread->per_user.end;
90 
91 	/* merge TIF_SINGLE_STEP into user specified PER registers. */
92 	if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
93 	    test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
94 		if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
95 			new.control |= PER_EVENT_BRANCH;
96 		else
97 			new.control |= PER_EVENT_IFETCH;
98 		new.control |= PER_CONTROL_SUSPENSION;
99 		new.control |= PER_EVENT_TRANSACTION_END;
100 		if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
101 			new.control |= PER_EVENT_IFETCH;
102 		new.start = 0;
103 		new.end = -1UL;
104 	}
105 
106 	/* Take care of the PER enablement bit in the PSW. */
107 	if (!(new.control & PER_EVENT_MASK)) {
108 		regs->psw.mask &= ~PSW_MASK_PER;
109 		return;
110 	}
111 	regs->psw.mask |= PSW_MASK_PER;
112 	__ctl_store(old, 9, 11);
113 	if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
114 		__ctl_load(new, 9, 11);
115 }
116 
117 void user_enable_single_step(struct task_struct *task)
118 {
119 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
120 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
121 }
122 
123 void user_disable_single_step(struct task_struct *task)
124 {
125 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
126 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
127 }
128 
129 void user_enable_block_step(struct task_struct *task)
130 {
131 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
132 	set_tsk_thread_flag(task, TIF_BLOCK_STEP);
133 }
134 
135 /*
136  * Called by kernel/ptrace.c when detaching..
137  *
138  * Clear all debugging related fields.
139  */
140 void ptrace_disable(struct task_struct *task)
141 {
142 	memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
143 	memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
144 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
145 	clear_pt_regs_flag(task_pt_regs(task), PIF_PER_TRAP);
146 	task->thread.per_flags = 0;
147 }
148 
149 #define __ADDR_MASK 7
150 
151 static inline unsigned long __peek_user_per(struct task_struct *child,
152 					    addr_t addr)
153 {
154 	struct per_struct_kernel *dummy = NULL;
155 
156 	if (addr == (addr_t) &dummy->cr9)
157 		/* Control bits of the active per set. */
158 		return test_thread_flag(TIF_SINGLE_STEP) ?
159 			PER_EVENT_IFETCH : child->thread.per_user.control;
160 	else if (addr == (addr_t) &dummy->cr10)
161 		/* Start address of the active per set. */
162 		return test_thread_flag(TIF_SINGLE_STEP) ?
163 			0 : child->thread.per_user.start;
164 	else if (addr == (addr_t) &dummy->cr11)
165 		/* End address of the active per set. */
166 		return test_thread_flag(TIF_SINGLE_STEP) ?
167 			-1UL : child->thread.per_user.end;
168 	else if (addr == (addr_t) &dummy->bits)
169 		/* Single-step bit. */
170 		return test_thread_flag(TIF_SINGLE_STEP) ?
171 			(1UL << (BITS_PER_LONG - 1)) : 0;
172 	else if (addr == (addr_t) &dummy->starting_addr)
173 		/* Start address of the user specified per set. */
174 		return child->thread.per_user.start;
175 	else if (addr == (addr_t) &dummy->ending_addr)
176 		/* End address of the user specified per set. */
177 		return child->thread.per_user.end;
178 	else if (addr == (addr_t) &dummy->perc_atmid)
179 		/* PER code, ATMID and AI of the last PER trap */
180 		return (unsigned long)
181 			child->thread.per_event.cause << (BITS_PER_LONG - 16);
182 	else if (addr == (addr_t) &dummy->address)
183 		/* Address of the last PER trap */
184 		return child->thread.per_event.address;
185 	else if (addr == (addr_t) &dummy->access_id)
186 		/* Access id of the last PER trap */
187 		return (unsigned long)
188 			child->thread.per_event.paid << (BITS_PER_LONG - 8);
189 	return 0;
190 }
191 
192 /*
193  * Read the word at offset addr from the user area of a process. The
194  * trouble here is that the information is littered over different
195  * locations. The process registers are found on the kernel stack,
196  * the floating point stuff and the trace settings are stored in
197  * the task structure. In addition the different structures in
198  * struct user contain pad bytes that should be read as zeroes.
199  * Lovely...
200  */
201 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
202 {
203 	struct user *dummy = NULL;
204 	addr_t offset, tmp;
205 
206 	if (addr < (addr_t) &dummy->regs.acrs) {
207 		/*
208 		 * psw and gprs are stored on the stack
209 		 */
210 		tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
211 		if (addr == (addr_t) &dummy->regs.psw.mask) {
212 			/* Return a clean psw mask. */
213 			tmp &= PSW_MASK_USER | PSW_MASK_RI;
214 			tmp |= PSW_USER_BITS;
215 		}
216 
217 	} else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
218 		/*
219 		 * access registers are stored in the thread structure
220 		 */
221 		offset = addr - (addr_t) &dummy->regs.acrs;
222 		/*
223 		 * Very special case: old & broken 64 bit gdb reading
224 		 * from acrs[15]. Result is a 64 bit value. Read the
225 		 * 32 bit acrs[15] value and shift it by 32. Sick...
226 		 */
227 		if (addr == (addr_t) &dummy->regs.acrs[15])
228 			tmp = ((unsigned long) child->thread.acrs[15]) << 32;
229 		else
230 			tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
231 
232 	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
233 		/*
234 		 * orig_gpr2 is stored on the kernel stack
235 		 */
236 		tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
237 
238 	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
239 		/*
240 		 * prevent reads of padding hole between
241 		 * orig_gpr2 and fp_regs on s390.
242 		 */
243 		tmp = 0;
244 
245 	} else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
246 		/*
247 		 * floating point control reg. is in the thread structure
248 		 */
249 		tmp = child->thread.fpu.fpc;
250 		tmp <<= BITS_PER_LONG - 32;
251 
252 	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
253 		/*
254 		 * floating point regs. are either in child->thread.fpu
255 		 * or the child->thread.fpu.vxrs array
256 		 */
257 		offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
258 		if (MACHINE_HAS_VX)
259 			tmp = *(addr_t *)
260 			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
261 		else
262 			tmp = *(addr_t *)
263 			       ((addr_t) child->thread.fpu.fprs + offset);
264 
265 	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
266 		/*
267 		 * Handle access to the per_info structure.
268 		 */
269 		addr -= (addr_t) &dummy->regs.per_info;
270 		tmp = __peek_user_per(child, addr);
271 
272 	} else
273 		tmp = 0;
274 
275 	return tmp;
276 }
277 
278 static int
279 peek_user(struct task_struct *child, addr_t addr, addr_t data)
280 {
281 	addr_t tmp, mask;
282 
283 	/*
284 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
285 	 * an alignment of 4. Programmers from hell...
286 	 */
287 	mask = __ADDR_MASK;
288 	if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
289 	    addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
290 		mask = 3;
291 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
292 		return -EIO;
293 
294 	tmp = __peek_user(child, addr);
295 	return put_user(tmp, (addr_t __user *) data);
296 }
297 
298 static inline void __poke_user_per(struct task_struct *child,
299 				   addr_t addr, addr_t data)
300 {
301 	struct per_struct_kernel *dummy = NULL;
302 
303 	/*
304 	 * There are only three fields in the per_info struct that the
305 	 * debugger user can write to.
306 	 * 1) cr9: the debugger wants to set a new PER event mask
307 	 * 2) starting_addr: the debugger wants to set a new starting
308 	 *    address to use with the PER event mask.
309 	 * 3) ending_addr: the debugger wants to set a new ending
310 	 *    address to use with the PER event mask.
311 	 * The user specified PER event mask and the start and end
312 	 * addresses are used only if single stepping is not in effect.
313 	 * Writes to any other field in per_info are ignored.
314 	 */
315 	if (addr == (addr_t) &dummy->cr9)
316 		/* PER event mask of the user specified per set. */
317 		child->thread.per_user.control =
318 			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
319 	else if (addr == (addr_t) &dummy->starting_addr)
320 		/* Starting address of the user specified per set. */
321 		child->thread.per_user.start = data;
322 	else if (addr == (addr_t) &dummy->ending_addr)
323 		/* Ending address of the user specified per set. */
324 		child->thread.per_user.end = data;
325 }
326 
327 /*
328  * Write a word to the user area of a process at location addr. This
329  * operation does have an additional problem compared to peek_user.
330  * Stores to the program status word and on the floating point
331  * control register needs to get checked for validity.
332  */
333 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
334 {
335 	struct user *dummy = NULL;
336 	addr_t offset;
337 
338 	if (addr < (addr_t) &dummy->regs.acrs) {
339 		/*
340 		 * psw and gprs are stored on the stack
341 		 */
342 		if (addr == (addr_t) &dummy->regs.psw.mask) {
343 			unsigned long mask = PSW_MASK_USER;
344 
345 			mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
346 			if ((data ^ PSW_USER_BITS) & ~mask)
347 				/* Invalid psw mask. */
348 				return -EINVAL;
349 			if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
350 				/* Invalid address-space-control bits */
351 				return -EINVAL;
352 			if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
353 				/* Invalid addressing mode bits */
354 				return -EINVAL;
355 		}
356 		*(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
357 
358 	} else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
359 		/*
360 		 * access registers are stored in the thread structure
361 		 */
362 		offset = addr - (addr_t) &dummy->regs.acrs;
363 		/*
364 		 * Very special case: old & broken 64 bit gdb writing
365 		 * to acrs[15] with a 64 bit value. Ignore the lower
366 		 * half of the value and write the upper 32 bit to
367 		 * acrs[15]. Sick...
368 		 */
369 		if (addr == (addr_t) &dummy->regs.acrs[15])
370 			child->thread.acrs[15] = (unsigned int) (data >> 32);
371 		else
372 			*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
373 
374 	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
375 		/*
376 		 * orig_gpr2 is stored on the kernel stack
377 		 */
378 		task_pt_regs(child)->orig_gpr2 = data;
379 
380 	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
381 		/*
382 		 * prevent writes of padding hole between
383 		 * orig_gpr2 and fp_regs on s390.
384 		 */
385 		return 0;
386 
387 	} else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
388 		/*
389 		 * floating point control reg. is in the thread structure
390 		 */
391 		if ((unsigned int) data != 0 ||
392 		    test_fp_ctl(data >> (BITS_PER_LONG - 32)))
393 			return -EINVAL;
394 		child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
395 
396 	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
397 		/*
398 		 * floating point regs. are either in child->thread.fpu
399 		 * or the child->thread.fpu.vxrs array
400 		 */
401 		offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
402 		if (MACHINE_HAS_VX)
403 			*(addr_t *)((addr_t)
404 				child->thread.fpu.vxrs + 2*offset) = data;
405 		else
406 			*(addr_t *)((addr_t)
407 				child->thread.fpu.fprs + offset) = data;
408 
409 	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
410 		/*
411 		 * Handle access to the per_info structure.
412 		 */
413 		addr -= (addr_t) &dummy->regs.per_info;
414 		__poke_user_per(child, addr, data);
415 
416 	}
417 
418 	return 0;
419 }
420 
421 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
422 {
423 	addr_t mask;
424 
425 	/*
426 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
427 	 * an alignment of 4. Programmers from hell indeed...
428 	 */
429 	mask = __ADDR_MASK;
430 	if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
431 	    addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
432 		mask = 3;
433 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
434 		return -EIO;
435 
436 	return __poke_user(child, addr, data);
437 }
438 
439 long arch_ptrace(struct task_struct *child, long request,
440 		 unsigned long addr, unsigned long data)
441 {
442 	ptrace_area parea;
443 	int copied, ret;
444 
445 	switch (request) {
446 	case PTRACE_PEEKUSR:
447 		/* read the word at location addr in the USER area. */
448 		return peek_user(child, addr, data);
449 
450 	case PTRACE_POKEUSR:
451 		/* write the word at location addr in the USER area */
452 		return poke_user(child, addr, data);
453 
454 	case PTRACE_PEEKUSR_AREA:
455 	case PTRACE_POKEUSR_AREA:
456 		if (copy_from_user(&parea, (void __force __user *) addr,
457 							sizeof(parea)))
458 			return -EFAULT;
459 		addr = parea.kernel_addr;
460 		data = parea.process_addr;
461 		copied = 0;
462 		while (copied < parea.len) {
463 			if (request == PTRACE_PEEKUSR_AREA)
464 				ret = peek_user(child, addr, data);
465 			else {
466 				addr_t utmp;
467 				if (get_user(utmp,
468 					     (addr_t __force __user *) data))
469 					return -EFAULT;
470 				ret = poke_user(child, addr, utmp);
471 			}
472 			if (ret)
473 				return ret;
474 			addr += sizeof(unsigned long);
475 			data += sizeof(unsigned long);
476 			copied += sizeof(unsigned long);
477 		}
478 		return 0;
479 	case PTRACE_GET_LAST_BREAK:
480 		put_user(child->thread.last_break,
481 			 (unsigned long __user *) data);
482 		return 0;
483 	case PTRACE_ENABLE_TE:
484 		if (!MACHINE_HAS_TE)
485 			return -EIO;
486 		child->thread.per_flags &= ~PER_FLAG_NO_TE;
487 		return 0;
488 	case PTRACE_DISABLE_TE:
489 		if (!MACHINE_HAS_TE)
490 			return -EIO;
491 		child->thread.per_flags |= PER_FLAG_NO_TE;
492 		child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
493 		return 0;
494 	case PTRACE_TE_ABORT_RAND:
495 		if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
496 			return -EIO;
497 		switch (data) {
498 		case 0UL:
499 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
500 			break;
501 		case 1UL:
502 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
503 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
504 			break;
505 		case 2UL:
506 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
507 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
508 			break;
509 		default:
510 			return -EINVAL;
511 		}
512 		return 0;
513 	default:
514 		return ptrace_request(child, request, addr, data);
515 	}
516 }
517 
518 #ifdef CONFIG_COMPAT
519 /*
520  * Now the fun part starts... a 31 bit program running in the
521  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
522  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
523  * to handle, the difference to the 64 bit versions of the requests
524  * is that the access is done in multiples of 4 byte instead of
525  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
526  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
527  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
528  * is a 31 bit program too, the content of struct user can be
529  * emulated. A 31 bit program peeking into the struct user of
530  * a 64 bit program is a no-no.
531  */
532 
533 /*
534  * Same as peek_user_per but for a 31 bit program.
535  */
536 static inline __u32 __peek_user_per_compat(struct task_struct *child,
537 					   addr_t addr)
538 {
539 	struct compat_per_struct_kernel *dummy32 = NULL;
540 
541 	if (addr == (addr_t) &dummy32->cr9)
542 		/* Control bits of the active per set. */
543 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
544 			PER_EVENT_IFETCH : child->thread.per_user.control;
545 	else if (addr == (addr_t) &dummy32->cr10)
546 		/* Start address of the active per set. */
547 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
548 			0 : child->thread.per_user.start;
549 	else if (addr == (addr_t) &dummy32->cr11)
550 		/* End address of the active per set. */
551 		return test_thread_flag(TIF_SINGLE_STEP) ?
552 			PSW32_ADDR_INSN : child->thread.per_user.end;
553 	else if (addr == (addr_t) &dummy32->bits)
554 		/* Single-step bit. */
555 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
556 			0x80000000 : 0;
557 	else if (addr == (addr_t) &dummy32->starting_addr)
558 		/* Start address of the user specified per set. */
559 		return (__u32) child->thread.per_user.start;
560 	else if (addr == (addr_t) &dummy32->ending_addr)
561 		/* End address of the user specified per set. */
562 		return (__u32) child->thread.per_user.end;
563 	else if (addr == (addr_t) &dummy32->perc_atmid)
564 		/* PER code, ATMID and AI of the last PER trap */
565 		return (__u32) child->thread.per_event.cause << 16;
566 	else if (addr == (addr_t) &dummy32->address)
567 		/* Address of the last PER trap */
568 		return (__u32) child->thread.per_event.address;
569 	else if (addr == (addr_t) &dummy32->access_id)
570 		/* Access id of the last PER trap */
571 		return (__u32) child->thread.per_event.paid << 24;
572 	return 0;
573 }
574 
575 /*
576  * Same as peek_user but for a 31 bit program.
577  */
578 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
579 {
580 	struct compat_user *dummy32 = NULL;
581 	addr_t offset;
582 	__u32 tmp;
583 
584 	if (addr < (addr_t) &dummy32->regs.acrs) {
585 		struct pt_regs *regs = task_pt_regs(child);
586 		/*
587 		 * psw and gprs are stored on the stack
588 		 */
589 		if (addr == (addr_t) &dummy32->regs.psw.mask) {
590 			/* Fake a 31 bit psw mask. */
591 			tmp = (__u32)(regs->psw.mask >> 32);
592 			tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
593 			tmp |= PSW32_USER_BITS;
594 		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
595 			/* Fake a 31 bit psw address. */
596 			tmp = (__u32) regs->psw.addr |
597 				(__u32)(regs->psw.mask & PSW_MASK_BA);
598 		} else {
599 			/* gpr 0-15 */
600 			tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
601 		}
602 	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
603 		/*
604 		 * access registers are stored in the thread structure
605 		 */
606 		offset = addr - (addr_t) &dummy32->regs.acrs;
607 		tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
608 
609 	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
610 		/*
611 		 * orig_gpr2 is stored on the kernel stack
612 		 */
613 		tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
614 
615 	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
616 		/*
617 		 * prevent reads of padding hole between
618 		 * orig_gpr2 and fp_regs on s390.
619 		 */
620 		tmp = 0;
621 
622 	} else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
623 		/*
624 		 * floating point control reg. is in the thread structure
625 		 */
626 		tmp = child->thread.fpu.fpc;
627 
628 	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
629 		/*
630 		 * floating point regs. are either in child->thread.fpu
631 		 * or the child->thread.fpu.vxrs array
632 		 */
633 		offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
634 		if (MACHINE_HAS_VX)
635 			tmp = *(__u32 *)
636 			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
637 		else
638 			tmp = *(__u32 *)
639 			       ((addr_t) child->thread.fpu.fprs + offset);
640 
641 	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
642 		/*
643 		 * Handle access to the per_info structure.
644 		 */
645 		addr -= (addr_t) &dummy32->regs.per_info;
646 		tmp = __peek_user_per_compat(child, addr);
647 
648 	} else
649 		tmp = 0;
650 
651 	return tmp;
652 }
653 
654 static int peek_user_compat(struct task_struct *child,
655 			    addr_t addr, addr_t data)
656 {
657 	__u32 tmp;
658 
659 	if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
660 		return -EIO;
661 
662 	tmp = __peek_user_compat(child, addr);
663 	return put_user(tmp, (__u32 __user *) data);
664 }
665 
666 /*
667  * Same as poke_user_per but for a 31 bit program.
668  */
669 static inline void __poke_user_per_compat(struct task_struct *child,
670 					  addr_t addr, __u32 data)
671 {
672 	struct compat_per_struct_kernel *dummy32 = NULL;
673 
674 	if (addr == (addr_t) &dummy32->cr9)
675 		/* PER event mask of the user specified per set. */
676 		child->thread.per_user.control =
677 			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
678 	else if (addr == (addr_t) &dummy32->starting_addr)
679 		/* Starting address of the user specified per set. */
680 		child->thread.per_user.start = data;
681 	else if (addr == (addr_t) &dummy32->ending_addr)
682 		/* Ending address of the user specified per set. */
683 		child->thread.per_user.end = data;
684 }
685 
686 /*
687  * Same as poke_user but for a 31 bit program.
688  */
689 static int __poke_user_compat(struct task_struct *child,
690 			      addr_t addr, addr_t data)
691 {
692 	struct compat_user *dummy32 = NULL;
693 	__u32 tmp = (__u32) data;
694 	addr_t offset;
695 
696 	if (addr < (addr_t) &dummy32->regs.acrs) {
697 		struct pt_regs *regs = task_pt_regs(child);
698 		/*
699 		 * psw, gprs, acrs and orig_gpr2 are stored on the stack
700 		 */
701 		if (addr == (addr_t) &dummy32->regs.psw.mask) {
702 			__u32 mask = PSW32_MASK_USER;
703 
704 			mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
705 			/* Build a 64 bit psw mask from 31 bit mask. */
706 			if ((tmp ^ PSW32_USER_BITS) & ~mask)
707 				/* Invalid psw mask. */
708 				return -EINVAL;
709 			if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
710 				/* Invalid address-space-control bits */
711 				return -EINVAL;
712 			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
713 				(regs->psw.mask & PSW_MASK_BA) |
714 				(__u64)(tmp & mask) << 32;
715 		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
716 			/* Build a 64 bit psw address from 31 bit address. */
717 			regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
718 			/* Transfer 31 bit amode bit to psw mask. */
719 			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
720 				(__u64)(tmp & PSW32_ADDR_AMODE);
721 		} else {
722 			/* gpr 0-15 */
723 			*(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
724 		}
725 	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
726 		/*
727 		 * access registers are stored in the thread structure
728 		 */
729 		offset = addr - (addr_t) &dummy32->regs.acrs;
730 		*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
731 
732 	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
733 		/*
734 		 * orig_gpr2 is stored on the kernel stack
735 		 */
736 		*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
737 
738 	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
739 		/*
740 		 * prevent writess of padding hole between
741 		 * orig_gpr2 and fp_regs on s390.
742 		 */
743 		return 0;
744 
745 	} else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
746 		/*
747 		 * floating point control reg. is in the thread structure
748 		 */
749 		if (test_fp_ctl(tmp))
750 			return -EINVAL;
751 		child->thread.fpu.fpc = data;
752 
753 	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
754 		/*
755 		 * floating point regs. are either in child->thread.fpu
756 		 * or the child->thread.fpu.vxrs array
757 		 */
758 		offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
759 		if (MACHINE_HAS_VX)
760 			*(__u32 *)((addr_t)
761 				child->thread.fpu.vxrs + 2*offset) = tmp;
762 		else
763 			*(__u32 *)((addr_t)
764 				child->thread.fpu.fprs + offset) = tmp;
765 
766 	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
767 		/*
768 		 * Handle access to the per_info structure.
769 		 */
770 		addr -= (addr_t) &dummy32->regs.per_info;
771 		__poke_user_per_compat(child, addr, data);
772 	}
773 
774 	return 0;
775 }
776 
777 static int poke_user_compat(struct task_struct *child,
778 			    addr_t addr, addr_t data)
779 {
780 	if (!is_compat_task() || (addr & 3) ||
781 	    addr > sizeof(struct compat_user) - 3)
782 		return -EIO;
783 
784 	return __poke_user_compat(child, addr, data);
785 }
786 
787 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
788 			compat_ulong_t caddr, compat_ulong_t cdata)
789 {
790 	unsigned long addr = caddr;
791 	unsigned long data = cdata;
792 	compat_ptrace_area parea;
793 	int copied, ret;
794 
795 	switch (request) {
796 	case PTRACE_PEEKUSR:
797 		/* read the word at location addr in the USER area. */
798 		return peek_user_compat(child, addr, data);
799 
800 	case PTRACE_POKEUSR:
801 		/* write the word at location addr in the USER area */
802 		return poke_user_compat(child, addr, data);
803 
804 	case PTRACE_PEEKUSR_AREA:
805 	case PTRACE_POKEUSR_AREA:
806 		if (copy_from_user(&parea, (void __force __user *) addr,
807 							sizeof(parea)))
808 			return -EFAULT;
809 		addr = parea.kernel_addr;
810 		data = parea.process_addr;
811 		copied = 0;
812 		while (copied < parea.len) {
813 			if (request == PTRACE_PEEKUSR_AREA)
814 				ret = peek_user_compat(child, addr, data);
815 			else {
816 				__u32 utmp;
817 				if (get_user(utmp,
818 					     (__u32 __force __user *) data))
819 					return -EFAULT;
820 				ret = poke_user_compat(child, addr, utmp);
821 			}
822 			if (ret)
823 				return ret;
824 			addr += sizeof(unsigned int);
825 			data += sizeof(unsigned int);
826 			copied += sizeof(unsigned int);
827 		}
828 		return 0;
829 	case PTRACE_GET_LAST_BREAK:
830 		put_user(child->thread.last_break,
831 			 (unsigned int __user *) data);
832 		return 0;
833 	}
834 	return compat_ptrace_request(child, request, addr, data);
835 }
836 #endif
837 
838 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
839 {
840 	unsigned long mask = -1UL;
841 
842 	/*
843 	 * The sysc_tracesys code in entry.S stored the system
844 	 * call number to gprs[2].
845 	 */
846 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
847 	    (tracehook_report_syscall_entry(regs) ||
848 	     regs->gprs[2] >= NR_syscalls)) {
849 		/*
850 		 * Tracing decided this syscall should not happen or the
851 		 * debugger stored an invalid system call number. Skip
852 		 * the system call and the system call restart handling.
853 		 */
854 		clear_pt_regs_flag(regs, PIF_SYSCALL);
855 		return -1;
856 	}
857 
858 	/* Do the secure computing check after ptrace. */
859 	if (secure_computing()) {
860 		/* seccomp failures shouldn't expose any additional code. */
861 		return -1;
862 	}
863 
864 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
865 		trace_sys_enter(regs, regs->gprs[2]);
866 
867 	if (is_compat_task())
868 		mask = 0xffffffff;
869 
870 	audit_syscall_entry(regs->gprs[2], regs->orig_gpr2 & mask,
871 			    regs->gprs[3] &mask, regs->gprs[4] &mask,
872 			    regs->gprs[5] &mask);
873 
874 	return regs->gprs[2];
875 }
876 
877 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
878 {
879 	audit_syscall_exit(regs);
880 
881 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
882 		trace_sys_exit(regs, regs->gprs[2]);
883 
884 	if (test_thread_flag(TIF_SYSCALL_TRACE))
885 		tracehook_report_syscall_exit(regs, 0);
886 }
887 
888 /*
889  * user_regset definitions.
890  */
891 
892 static int s390_regs_get(struct task_struct *target,
893 			 const struct user_regset *regset,
894 			 unsigned int pos, unsigned int count,
895 			 void *kbuf, void __user *ubuf)
896 {
897 	if (target == current)
898 		save_access_regs(target->thread.acrs);
899 
900 	if (kbuf) {
901 		unsigned long *k = kbuf;
902 		while (count > 0) {
903 			*k++ = __peek_user(target, pos);
904 			count -= sizeof(*k);
905 			pos += sizeof(*k);
906 		}
907 	} else {
908 		unsigned long __user *u = ubuf;
909 		while (count > 0) {
910 			if (__put_user(__peek_user(target, pos), u++))
911 				return -EFAULT;
912 			count -= sizeof(*u);
913 			pos += sizeof(*u);
914 		}
915 	}
916 	return 0;
917 }
918 
919 static int s390_regs_set(struct task_struct *target,
920 			 const struct user_regset *regset,
921 			 unsigned int pos, unsigned int count,
922 			 const void *kbuf, const void __user *ubuf)
923 {
924 	int rc = 0;
925 
926 	if (target == current)
927 		save_access_regs(target->thread.acrs);
928 
929 	if (kbuf) {
930 		const unsigned long *k = kbuf;
931 		while (count > 0 && !rc) {
932 			rc = __poke_user(target, pos, *k++);
933 			count -= sizeof(*k);
934 			pos += sizeof(*k);
935 		}
936 	} else {
937 		const unsigned long  __user *u = ubuf;
938 		while (count > 0 && !rc) {
939 			unsigned long word;
940 			rc = __get_user(word, u++);
941 			if (rc)
942 				break;
943 			rc = __poke_user(target, pos, word);
944 			count -= sizeof(*u);
945 			pos += sizeof(*u);
946 		}
947 	}
948 
949 	if (rc == 0 && target == current)
950 		restore_access_regs(target->thread.acrs);
951 
952 	return rc;
953 }
954 
955 static int s390_fpregs_get(struct task_struct *target,
956 			   const struct user_regset *regset, unsigned int pos,
957 			   unsigned int count, void *kbuf, void __user *ubuf)
958 {
959 	_s390_fp_regs fp_regs;
960 
961 	if (target == current)
962 		save_fpu_regs();
963 
964 	fp_regs.fpc = target->thread.fpu.fpc;
965 	fpregs_store(&fp_regs, &target->thread.fpu);
966 
967 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
968 				   &fp_regs, 0, -1);
969 }
970 
971 static int s390_fpregs_set(struct task_struct *target,
972 			   const struct user_regset *regset, unsigned int pos,
973 			   unsigned int count, const void *kbuf,
974 			   const void __user *ubuf)
975 {
976 	int rc = 0;
977 	freg_t fprs[__NUM_FPRS];
978 
979 	if (target == current)
980 		save_fpu_regs();
981 
982 	if (MACHINE_HAS_VX)
983 		convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
984 	else
985 		memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
986 
987 	/* If setting FPC, must validate it first. */
988 	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
989 		u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
990 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
991 					0, offsetof(s390_fp_regs, fprs));
992 		if (rc)
993 			return rc;
994 		if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
995 			return -EINVAL;
996 		target->thread.fpu.fpc = ufpc[0];
997 	}
998 
999 	if (rc == 0 && count > 0)
1000 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1001 					fprs, offsetof(s390_fp_regs, fprs), -1);
1002 	if (rc)
1003 		return rc;
1004 
1005 	if (MACHINE_HAS_VX)
1006 		convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
1007 	else
1008 		memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
1009 
1010 	return rc;
1011 }
1012 
1013 static int s390_last_break_get(struct task_struct *target,
1014 			       const struct user_regset *regset,
1015 			       unsigned int pos, unsigned int count,
1016 			       void *kbuf, void __user *ubuf)
1017 {
1018 	if (count > 0) {
1019 		if (kbuf) {
1020 			unsigned long *k = kbuf;
1021 			*k = target->thread.last_break;
1022 		} else {
1023 			unsigned long  __user *u = ubuf;
1024 			if (__put_user(target->thread.last_break, u))
1025 				return -EFAULT;
1026 		}
1027 	}
1028 	return 0;
1029 }
1030 
1031 static int s390_last_break_set(struct task_struct *target,
1032 			       const struct user_regset *regset,
1033 			       unsigned int pos, unsigned int count,
1034 			       const void *kbuf, const void __user *ubuf)
1035 {
1036 	return 0;
1037 }
1038 
1039 static int s390_tdb_get(struct task_struct *target,
1040 			const struct user_regset *regset,
1041 			unsigned int pos, unsigned int count,
1042 			void *kbuf, void __user *ubuf)
1043 {
1044 	struct pt_regs *regs = task_pt_regs(target);
1045 	unsigned char *data;
1046 
1047 	if (!(regs->int_code & 0x200))
1048 		return -ENODATA;
1049 	data = target->thread.trap_tdb;
1050 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
1051 }
1052 
1053 static int s390_tdb_set(struct task_struct *target,
1054 			const struct user_regset *regset,
1055 			unsigned int pos, unsigned int count,
1056 			const void *kbuf, const void __user *ubuf)
1057 {
1058 	return 0;
1059 }
1060 
1061 static int s390_vxrs_low_get(struct task_struct *target,
1062 			     const struct user_regset *regset,
1063 			     unsigned int pos, unsigned int count,
1064 			     void *kbuf, void __user *ubuf)
1065 {
1066 	__u64 vxrs[__NUM_VXRS_LOW];
1067 	int i;
1068 
1069 	if (!MACHINE_HAS_VX)
1070 		return -ENODEV;
1071 	if (target == current)
1072 		save_fpu_regs();
1073 	for (i = 0; i < __NUM_VXRS_LOW; i++)
1074 		vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1075 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1076 }
1077 
1078 static int s390_vxrs_low_set(struct task_struct *target,
1079 			     const struct user_regset *regset,
1080 			     unsigned int pos, unsigned int count,
1081 			     const void *kbuf, const void __user *ubuf)
1082 {
1083 	__u64 vxrs[__NUM_VXRS_LOW];
1084 	int i, rc;
1085 
1086 	if (!MACHINE_HAS_VX)
1087 		return -ENODEV;
1088 	if (target == current)
1089 		save_fpu_regs();
1090 
1091 	for (i = 0; i < __NUM_VXRS_LOW; i++)
1092 		vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1093 
1094 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1095 	if (rc == 0)
1096 		for (i = 0; i < __NUM_VXRS_LOW; i++)
1097 			*((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1098 
1099 	return rc;
1100 }
1101 
1102 static int s390_vxrs_high_get(struct task_struct *target,
1103 			      const struct user_regset *regset,
1104 			      unsigned int pos, unsigned int count,
1105 			      void *kbuf, void __user *ubuf)
1106 {
1107 	__vector128 vxrs[__NUM_VXRS_HIGH];
1108 
1109 	if (!MACHINE_HAS_VX)
1110 		return -ENODEV;
1111 	if (target == current)
1112 		save_fpu_regs();
1113 	memcpy(vxrs, target->thread.fpu.vxrs + __NUM_VXRS_LOW, sizeof(vxrs));
1114 
1115 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1116 }
1117 
1118 static int s390_vxrs_high_set(struct task_struct *target,
1119 			      const struct user_regset *regset,
1120 			      unsigned int pos, unsigned int count,
1121 			      const void *kbuf, const void __user *ubuf)
1122 {
1123 	int rc;
1124 
1125 	if (!MACHINE_HAS_VX)
1126 		return -ENODEV;
1127 	if (target == current)
1128 		save_fpu_regs();
1129 
1130 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1131 				target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1132 	return rc;
1133 }
1134 
1135 static int s390_system_call_get(struct task_struct *target,
1136 				const struct user_regset *regset,
1137 				unsigned int pos, unsigned int count,
1138 				void *kbuf, void __user *ubuf)
1139 {
1140 	unsigned int *data = &target->thread.system_call;
1141 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1142 				   data, 0, sizeof(unsigned int));
1143 }
1144 
1145 static int s390_system_call_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 	unsigned int *data = &target->thread.system_call;
1151 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1152 				  data, 0, sizeof(unsigned int));
1153 }
1154 
1155 static int s390_gs_cb_get(struct task_struct *target,
1156 			  const struct user_regset *regset,
1157 			  unsigned int pos, unsigned int count,
1158 			  void *kbuf, void __user *ubuf)
1159 {
1160 	struct gs_cb *data = target->thread.gs_cb;
1161 
1162 	if (!MACHINE_HAS_GS)
1163 		return -ENODEV;
1164 	if (!data)
1165 		return -ENODATA;
1166 	if (target == current)
1167 		save_gs_cb(data);
1168 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1169 				   data, 0, sizeof(struct gs_cb));
1170 }
1171 
1172 static int s390_gs_cb_set(struct task_struct *target,
1173 			  const struct user_regset *regset,
1174 			  unsigned int pos, unsigned int count,
1175 			  const void *kbuf, const void __user *ubuf)
1176 {
1177 	struct gs_cb gs_cb = { }, *data = NULL;
1178 	int rc;
1179 
1180 	if (!MACHINE_HAS_GS)
1181 		return -ENODEV;
1182 	if (!target->thread.gs_cb) {
1183 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1184 		if (!data)
1185 			return -ENOMEM;
1186 	}
1187 	if (!target->thread.gs_cb)
1188 		gs_cb.gsd = 25;
1189 	else if (target == current)
1190 		save_gs_cb(&gs_cb);
1191 	else
1192 		gs_cb = *target->thread.gs_cb;
1193 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1194 				&gs_cb, 0, sizeof(gs_cb));
1195 	if (rc) {
1196 		kfree(data);
1197 		return -EFAULT;
1198 	}
1199 	preempt_disable();
1200 	if (!target->thread.gs_cb)
1201 		target->thread.gs_cb = data;
1202 	*target->thread.gs_cb = gs_cb;
1203 	if (target == current) {
1204 		__ctl_set_bit(2, 4);
1205 		restore_gs_cb(target->thread.gs_cb);
1206 	}
1207 	preempt_enable();
1208 	return rc;
1209 }
1210 
1211 static int s390_gs_bc_get(struct task_struct *target,
1212 			  const struct user_regset *regset,
1213 			  unsigned int pos, unsigned int count,
1214 			  void *kbuf, void __user *ubuf)
1215 {
1216 	struct gs_cb *data = target->thread.gs_bc_cb;
1217 
1218 	if (!MACHINE_HAS_GS)
1219 		return -ENODEV;
1220 	if (!data)
1221 		return -ENODATA;
1222 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1223 				   data, 0, sizeof(struct gs_cb));
1224 }
1225 
1226 static int s390_gs_bc_set(struct task_struct *target,
1227 			  const struct user_regset *regset,
1228 			  unsigned int pos, unsigned int count,
1229 			  const void *kbuf, const void __user *ubuf)
1230 {
1231 	struct gs_cb *data = target->thread.gs_bc_cb;
1232 
1233 	if (!MACHINE_HAS_GS)
1234 		return -ENODEV;
1235 	if (!data) {
1236 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1237 		if (!data)
1238 			return -ENOMEM;
1239 		target->thread.gs_bc_cb = data;
1240 	}
1241 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1242 				  data, 0, sizeof(struct gs_cb));
1243 }
1244 
1245 static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1246 {
1247 	return (cb->rca & 0x1f) == 0 &&
1248 		(cb->roa & 0xfff) == 0 &&
1249 		(cb->rla & 0xfff) == 0xfff &&
1250 		cb->s == 1 &&
1251 		cb->k == 1 &&
1252 		cb->h == 0 &&
1253 		cb->reserved1 == 0 &&
1254 		cb->ps == 1 &&
1255 		cb->qs == 0 &&
1256 		cb->pc == 1 &&
1257 		cb->qc == 0 &&
1258 		cb->reserved2 == 0 &&
1259 		cb->key == PAGE_DEFAULT_KEY &&
1260 		cb->reserved3 == 0 &&
1261 		cb->reserved4 == 0 &&
1262 		cb->reserved5 == 0 &&
1263 		cb->reserved6 == 0 &&
1264 		cb->reserved7 == 0 &&
1265 		cb->reserved8 == 0 &&
1266 		cb->rla >= cb->roa &&
1267 		cb->rca >= cb->roa &&
1268 		cb->rca <= cb->rla+1 &&
1269 		cb->m < 3;
1270 }
1271 
1272 static int s390_runtime_instr_get(struct task_struct *target,
1273 				const struct user_regset *regset,
1274 				unsigned int pos, unsigned int count,
1275 				void *kbuf, void __user *ubuf)
1276 {
1277 	struct runtime_instr_cb *data = target->thread.ri_cb;
1278 
1279 	if (!test_facility(64))
1280 		return -ENODEV;
1281 	if (!data)
1282 		return -ENODATA;
1283 
1284 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1285 				   data, 0, sizeof(struct runtime_instr_cb));
1286 }
1287 
1288 static int s390_runtime_instr_set(struct task_struct *target,
1289 				  const struct user_regset *regset,
1290 				  unsigned int pos, unsigned int count,
1291 				  const void *kbuf, const void __user *ubuf)
1292 {
1293 	struct runtime_instr_cb ri_cb = { }, *data = NULL;
1294 	int rc;
1295 
1296 	if (!test_facility(64))
1297 		return -ENODEV;
1298 
1299 	if (!target->thread.ri_cb) {
1300 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1301 		if (!data)
1302 			return -ENOMEM;
1303 	}
1304 
1305 	if (target->thread.ri_cb) {
1306 		if (target == current)
1307 			store_runtime_instr_cb(&ri_cb);
1308 		else
1309 			ri_cb = *target->thread.ri_cb;
1310 	}
1311 
1312 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1313 				&ri_cb, 0, sizeof(struct runtime_instr_cb));
1314 	if (rc) {
1315 		kfree(data);
1316 		return -EFAULT;
1317 	}
1318 
1319 	if (!is_ri_cb_valid(&ri_cb)) {
1320 		kfree(data);
1321 		return -EINVAL;
1322 	}
1323 
1324 	preempt_disable();
1325 	if (!target->thread.ri_cb)
1326 		target->thread.ri_cb = data;
1327 	*target->thread.ri_cb = ri_cb;
1328 	if (target == current)
1329 		load_runtime_instr_cb(target->thread.ri_cb);
1330 	preempt_enable();
1331 
1332 	return 0;
1333 }
1334 
1335 static const struct user_regset s390_regsets[] = {
1336 	{
1337 		.core_note_type = NT_PRSTATUS,
1338 		.n = sizeof(s390_regs) / sizeof(long),
1339 		.size = sizeof(long),
1340 		.align = sizeof(long),
1341 		.get = s390_regs_get,
1342 		.set = s390_regs_set,
1343 	},
1344 	{
1345 		.core_note_type = NT_PRFPREG,
1346 		.n = sizeof(s390_fp_regs) / sizeof(long),
1347 		.size = sizeof(long),
1348 		.align = sizeof(long),
1349 		.get = s390_fpregs_get,
1350 		.set = s390_fpregs_set,
1351 	},
1352 	{
1353 		.core_note_type = NT_S390_SYSTEM_CALL,
1354 		.n = 1,
1355 		.size = sizeof(unsigned int),
1356 		.align = sizeof(unsigned int),
1357 		.get = s390_system_call_get,
1358 		.set = s390_system_call_set,
1359 	},
1360 	{
1361 		.core_note_type = NT_S390_LAST_BREAK,
1362 		.n = 1,
1363 		.size = sizeof(long),
1364 		.align = sizeof(long),
1365 		.get = s390_last_break_get,
1366 		.set = s390_last_break_set,
1367 	},
1368 	{
1369 		.core_note_type = NT_S390_TDB,
1370 		.n = 1,
1371 		.size = 256,
1372 		.align = 1,
1373 		.get = s390_tdb_get,
1374 		.set = s390_tdb_set,
1375 	},
1376 	{
1377 		.core_note_type = NT_S390_VXRS_LOW,
1378 		.n = __NUM_VXRS_LOW,
1379 		.size = sizeof(__u64),
1380 		.align = sizeof(__u64),
1381 		.get = s390_vxrs_low_get,
1382 		.set = s390_vxrs_low_set,
1383 	},
1384 	{
1385 		.core_note_type = NT_S390_VXRS_HIGH,
1386 		.n = __NUM_VXRS_HIGH,
1387 		.size = sizeof(__vector128),
1388 		.align = sizeof(__vector128),
1389 		.get = s390_vxrs_high_get,
1390 		.set = s390_vxrs_high_set,
1391 	},
1392 	{
1393 		.core_note_type = NT_S390_GS_CB,
1394 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1395 		.size = sizeof(__u64),
1396 		.align = sizeof(__u64),
1397 		.get = s390_gs_cb_get,
1398 		.set = s390_gs_cb_set,
1399 	},
1400 	{
1401 		.core_note_type = NT_S390_GS_BC,
1402 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1403 		.size = sizeof(__u64),
1404 		.align = sizeof(__u64),
1405 		.get = s390_gs_bc_get,
1406 		.set = s390_gs_bc_set,
1407 	},
1408 	{
1409 		.core_note_type = NT_S390_RI_CB,
1410 		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1411 		.size = sizeof(__u64),
1412 		.align = sizeof(__u64),
1413 		.get = s390_runtime_instr_get,
1414 		.set = s390_runtime_instr_set,
1415 	},
1416 };
1417 
1418 static const struct user_regset_view user_s390_view = {
1419 	.name = UTS_MACHINE,
1420 	.e_machine = EM_S390,
1421 	.regsets = s390_regsets,
1422 	.n = ARRAY_SIZE(s390_regsets)
1423 };
1424 
1425 #ifdef CONFIG_COMPAT
1426 static int s390_compat_regs_get(struct task_struct *target,
1427 				const struct user_regset *regset,
1428 				unsigned int pos, unsigned int count,
1429 				void *kbuf, void __user *ubuf)
1430 {
1431 	if (target == current)
1432 		save_access_regs(target->thread.acrs);
1433 
1434 	if (kbuf) {
1435 		compat_ulong_t *k = kbuf;
1436 		while (count > 0) {
1437 			*k++ = __peek_user_compat(target, pos);
1438 			count -= sizeof(*k);
1439 			pos += sizeof(*k);
1440 		}
1441 	} else {
1442 		compat_ulong_t __user *u = ubuf;
1443 		while (count > 0) {
1444 			if (__put_user(__peek_user_compat(target, pos), u++))
1445 				return -EFAULT;
1446 			count -= sizeof(*u);
1447 			pos += sizeof(*u);
1448 		}
1449 	}
1450 	return 0;
1451 }
1452 
1453 static int s390_compat_regs_set(struct task_struct *target,
1454 				const struct user_regset *regset,
1455 				unsigned int pos, unsigned int count,
1456 				const void *kbuf, const void __user *ubuf)
1457 {
1458 	int rc = 0;
1459 
1460 	if (target == current)
1461 		save_access_regs(target->thread.acrs);
1462 
1463 	if (kbuf) {
1464 		const compat_ulong_t *k = kbuf;
1465 		while (count > 0 && !rc) {
1466 			rc = __poke_user_compat(target, pos, *k++);
1467 			count -= sizeof(*k);
1468 			pos += sizeof(*k);
1469 		}
1470 	} else {
1471 		const compat_ulong_t  __user *u = ubuf;
1472 		while (count > 0 && !rc) {
1473 			compat_ulong_t word;
1474 			rc = __get_user(word, u++);
1475 			if (rc)
1476 				break;
1477 			rc = __poke_user_compat(target, pos, word);
1478 			count -= sizeof(*u);
1479 			pos += sizeof(*u);
1480 		}
1481 	}
1482 
1483 	if (rc == 0 && target == current)
1484 		restore_access_regs(target->thread.acrs);
1485 
1486 	return rc;
1487 }
1488 
1489 static int s390_compat_regs_high_get(struct task_struct *target,
1490 				     const struct user_regset *regset,
1491 				     unsigned int pos, unsigned int count,
1492 				     void *kbuf, void __user *ubuf)
1493 {
1494 	compat_ulong_t *gprs_high;
1495 
1496 	gprs_high = (compat_ulong_t *)
1497 		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1498 	if (kbuf) {
1499 		compat_ulong_t *k = kbuf;
1500 		while (count > 0) {
1501 			*k++ = *gprs_high;
1502 			gprs_high += 2;
1503 			count -= sizeof(*k);
1504 		}
1505 	} else {
1506 		compat_ulong_t __user *u = ubuf;
1507 		while (count > 0) {
1508 			if (__put_user(*gprs_high, u++))
1509 				return -EFAULT;
1510 			gprs_high += 2;
1511 			count -= sizeof(*u);
1512 		}
1513 	}
1514 	return 0;
1515 }
1516 
1517 static int s390_compat_regs_high_set(struct task_struct *target,
1518 				     const struct user_regset *regset,
1519 				     unsigned int pos, unsigned int count,
1520 				     const void *kbuf, const void __user *ubuf)
1521 {
1522 	compat_ulong_t *gprs_high;
1523 	int rc = 0;
1524 
1525 	gprs_high = (compat_ulong_t *)
1526 		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1527 	if (kbuf) {
1528 		const compat_ulong_t *k = kbuf;
1529 		while (count > 0) {
1530 			*gprs_high = *k++;
1531 			*gprs_high += 2;
1532 			count -= sizeof(*k);
1533 		}
1534 	} else {
1535 		const compat_ulong_t  __user *u = ubuf;
1536 		while (count > 0 && !rc) {
1537 			unsigned long word;
1538 			rc = __get_user(word, u++);
1539 			if (rc)
1540 				break;
1541 			*gprs_high = word;
1542 			*gprs_high += 2;
1543 			count -= sizeof(*u);
1544 		}
1545 	}
1546 
1547 	return rc;
1548 }
1549 
1550 static int s390_compat_last_break_get(struct task_struct *target,
1551 				      const struct user_regset *regset,
1552 				      unsigned int pos, unsigned int count,
1553 				      void *kbuf, void __user *ubuf)
1554 {
1555 	compat_ulong_t last_break;
1556 
1557 	if (count > 0) {
1558 		last_break = target->thread.last_break;
1559 		if (kbuf) {
1560 			unsigned long *k = kbuf;
1561 			*k = last_break;
1562 		} else {
1563 			unsigned long  __user *u = ubuf;
1564 			if (__put_user(last_break, u))
1565 				return -EFAULT;
1566 		}
1567 	}
1568 	return 0;
1569 }
1570 
1571 static int s390_compat_last_break_set(struct task_struct *target,
1572 				      const struct user_regset *regset,
1573 				      unsigned int pos, unsigned int count,
1574 				      const void *kbuf, const void __user *ubuf)
1575 {
1576 	return 0;
1577 }
1578 
1579 static const struct user_regset s390_compat_regsets[] = {
1580 	{
1581 		.core_note_type = NT_PRSTATUS,
1582 		.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1583 		.size = sizeof(compat_long_t),
1584 		.align = sizeof(compat_long_t),
1585 		.get = s390_compat_regs_get,
1586 		.set = s390_compat_regs_set,
1587 	},
1588 	{
1589 		.core_note_type = NT_PRFPREG,
1590 		.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1591 		.size = sizeof(compat_long_t),
1592 		.align = sizeof(compat_long_t),
1593 		.get = s390_fpregs_get,
1594 		.set = s390_fpregs_set,
1595 	},
1596 	{
1597 		.core_note_type = NT_S390_SYSTEM_CALL,
1598 		.n = 1,
1599 		.size = sizeof(compat_uint_t),
1600 		.align = sizeof(compat_uint_t),
1601 		.get = s390_system_call_get,
1602 		.set = s390_system_call_set,
1603 	},
1604 	{
1605 		.core_note_type = NT_S390_LAST_BREAK,
1606 		.n = 1,
1607 		.size = sizeof(long),
1608 		.align = sizeof(long),
1609 		.get = s390_compat_last_break_get,
1610 		.set = s390_compat_last_break_set,
1611 	},
1612 	{
1613 		.core_note_type = NT_S390_TDB,
1614 		.n = 1,
1615 		.size = 256,
1616 		.align = 1,
1617 		.get = s390_tdb_get,
1618 		.set = s390_tdb_set,
1619 	},
1620 	{
1621 		.core_note_type = NT_S390_VXRS_LOW,
1622 		.n = __NUM_VXRS_LOW,
1623 		.size = sizeof(__u64),
1624 		.align = sizeof(__u64),
1625 		.get = s390_vxrs_low_get,
1626 		.set = s390_vxrs_low_set,
1627 	},
1628 	{
1629 		.core_note_type = NT_S390_VXRS_HIGH,
1630 		.n = __NUM_VXRS_HIGH,
1631 		.size = sizeof(__vector128),
1632 		.align = sizeof(__vector128),
1633 		.get = s390_vxrs_high_get,
1634 		.set = s390_vxrs_high_set,
1635 	},
1636 	{
1637 		.core_note_type = NT_S390_HIGH_GPRS,
1638 		.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1639 		.size = sizeof(compat_long_t),
1640 		.align = sizeof(compat_long_t),
1641 		.get = s390_compat_regs_high_get,
1642 		.set = s390_compat_regs_high_set,
1643 	},
1644 	{
1645 		.core_note_type = NT_S390_GS_CB,
1646 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1647 		.size = sizeof(__u64),
1648 		.align = sizeof(__u64),
1649 		.get = s390_gs_cb_get,
1650 		.set = s390_gs_cb_set,
1651 	},
1652 	{
1653 		.core_note_type = NT_S390_GS_BC,
1654 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1655 		.size = sizeof(__u64),
1656 		.align = sizeof(__u64),
1657 		.get = s390_gs_bc_get,
1658 		.set = s390_gs_bc_set,
1659 	},
1660 	{
1661 		.core_note_type = NT_S390_RI_CB,
1662 		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1663 		.size = sizeof(__u64),
1664 		.align = sizeof(__u64),
1665 		.get = s390_runtime_instr_get,
1666 		.set = s390_runtime_instr_set,
1667 	},
1668 };
1669 
1670 static const struct user_regset_view user_s390_compat_view = {
1671 	.name = "s390",
1672 	.e_machine = EM_S390,
1673 	.regsets = s390_compat_regsets,
1674 	.n = ARRAY_SIZE(s390_compat_regsets)
1675 };
1676 #endif
1677 
1678 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1679 {
1680 #ifdef CONFIG_COMPAT
1681 	if (test_tsk_thread_flag(task, TIF_31BIT))
1682 		return &user_s390_compat_view;
1683 #endif
1684 	return &user_s390_view;
1685 }
1686 
1687 static const char *gpr_names[NUM_GPRS] = {
1688 	"r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1689 	"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1690 };
1691 
1692 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1693 {
1694 	if (offset >= NUM_GPRS)
1695 		return 0;
1696 	return regs->gprs[offset];
1697 }
1698 
1699 int regs_query_register_offset(const char *name)
1700 {
1701 	unsigned long offset;
1702 
1703 	if (!name || *name != 'r')
1704 		return -EINVAL;
1705 	if (kstrtoul(name + 1, 10, &offset))
1706 		return -EINVAL;
1707 	if (offset >= NUM_GPRS)
1708 		return -EINVAL;
1709 	return offset;
1710 }
1711 
1712 const char *regs_query_register_name(unsigned int offset)
1713 {
1714 	if (offset >= NUM_GPRS)
1715 		return NULL;
1716 	return gpr_names[offset];
1717 }
1718 
1719 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1720 {
1721 	unsigned long ksp = kernel_stack_pointer(regs);
1722 
1723 	return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1724 }
1725 
1726 /**
1727  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1728  * @regs:pt_regs which contains kernel stack pointer.
1729  * @n:stack entry number.
1730  *
1731  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1732  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1733  * this returns 0.
1734  */
1735 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1736 {
1737 	unsigned long addr;
1738 
1739 	addr = kernel_stack_pointer(regs) + n * sizeof(long);
1740 	if (!regs_within_kernel_stack(regs, addr))
1741 		return 0;
1742 	return *(unsigned long *)addr;
1743 }
1744