xref: /openbmc/linux/arch/s390/kernel/ptrace.c (revision feac8c8b)
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/segment.h>
28 #include <asm/page.h>
29 #include <asm/pgtable.h>
30 #include <asm/pgalloc.h>
31 #include <linux/uaccess.h>
32 #include <asm/unistd.h>
33 #include <asm/switch_to.h>
34 #include <asm/runtime_instr.h>
35 #include <asm/facility.h>
36 
37 #include "entry.h"
38 
39 #ifdef CONFIG_COMPAT
40 #include "compat_ptrace.h"
41 #endif
42 
43 #define CREATE_TRACE_POINTS
44 #include <trace/events/syscalls.h>
45 
46 void update_cr_regs(struct task_struct *task)
47 {
48 	struct pt_regs *regs = task_pt_regs(task);
49 	struct thread_struct *thread = &task->thread;
50 	struct per_regs old, new;
51 	union ctlreg0 cr0_old, cr0_new;
52 	union ctlreg2 cr2_old, cr2_new;
53 	int cr0_changed, cr2_changed;
54 
55 	__ctl_store(cr0_old.val, 0, 0);
56 	__ctl_store(cr2_old.val, 2, 2);
57 	cr0_new = cr0_old;
58 	cr2_new = cr2_old;
59 	/* Take care of the enable/disable of transactional execution. */
60 	if (MACHINE_HAS_TE) {
61 		/* Set or clear transaction execution TXC bit 8. */
62 		cr0_new.tcx = 1;
63 		if (task->thread.per_flags & PER_FLAG_NO_TE)
64 			cr0_new.tcx = 0;
65 		/* Set or clear transaction execution TDC bits 62 and 63. */
66 		cr2_new.tdc = 0;
67 		if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
68 			if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
69 				cr2_new.tdc = 1;
70 			else
71 				cr2_new.tdc = 2;
72 		}
73 	}
74 	/* Take care of enable/disable of guarded storage. */
75 	if (MACHINE_HAS_GS) {
76 		cr2_new.gse = 0;
77 		if (task->thread.gs_cb)
78 			cr2_new.gse = 1;
79 	}
80 	/* Load control register 0/2 iff changed */
81 	cr0_changed = cr0_new.val != cr0_old.val;
82 	cr2_changed = cr2_new.val != cr2_old.val;
83 	if (cr0_changed)
84 		__ctl_load(cr0_new.val, 0, 0);
85 	if (cr2_changed)
86 		__ctl_load(cr2_new.val, 2, 2);
87 	/* Copy user specified PER registers */
88 	new.control = thread->per_user.control;
89 	new.start = thread->per_user.start;
90 	new.end = thread->per_user.end;
91 
92 	/* merge TIF_SINGLE_STEP into user specified PER registers. */
93 	if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
94 	    test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
95 		if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
96 			new.control |= PER_EVENT_BRANCH;
97 		else
98 			new.control |= PER_EVENT_IFETCH;
99 		new.control |= PER_CONTROL_SUSPENSION;
100 		new.control |= PER_EVENT_TRANSACTION_END;
101 		if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
102 			new.control |= PER_EVENT_IFETCH;
103 		new.start = 0;
104 		new.end = -1UL;
105 	}
106 
107 	/* Take care of the PER enablement bit in the PSW. */
108 	if (!(new.control & PER_EVENT_MASK)) {
109 		regs->psw.mask &= ~PSW_MASK_PER;
110 		return;
111 	}
112 	regs->psw.mask |= PSW_MASK_PER;
113 	__ctl_store(old, 9, 11);
114 	if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
115 		__ctl_load(new, 9, 11);
116 }
117 
118 void user_enable_single_step(struct task_struct *task)
119 {
120 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
121 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
122 }
123 
124 void user_disable_single_step(struct task_struct *task)
125 {
126 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
127 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
128 }
129 
130 void user_enable_block_step(struct task_struct *task)
131 {
132 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
133 	set_tsk_thread_flag(task, TIF_BLOCK_STEP);
134 }
135 
136 /*
137  * Called by kernel/ptrace.c when detaching..
138  *
139  * Clear all debugging related fields.
140  */
141 void ptrace_disable(struct task_struct *task)
142 {
143 	memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
144 	memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
145 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
146 	clear_pt_regs_flag(task_pt_regs(task), PIF_PER_TRAP);
147 	task->thread.per_flags = 0;
148 }
149 
150 #define __ADDR_MASK 7
151 
152 static inline unsigned long __peek_user_per(struct task_struct *child,
153 					    addr_t addr)
154 {
155 	struct per_struct_kernel *dummy = NULL;
156 
157 	if (addr == (addr_t) &dummy->cr9)
158 		/* Control bits of the active per set. */
159 		return test_thread_flag(TIF_SINGLE_STEP) ?
160 			PER_EVENT_IFETCH : child->thread.per_user.control;
161 	else if (addr == (addr_t) &dummy->cr10)
162 		/* Start address of the active per set. */
163 		return test_thread_flag(TIF_SINGLE_STEP) ?
164 			0 : child->thread.per_user.start;
165 	else if (addr == (addr_t) &dummy->cr11)
166 		/* End address of the active per set. */
167 		return test_thread_flag(TIF_SINGLE_STEP) ?
168 			-1UL : child->thread.per_user.end;
169 	else if (addr == (addr_t) &dummy->bits)
170 		/* Single-step bit. */
171 		return test_thread_flag(TIF_SINGLE_STEP) ?
172 			(1UL << (BITS_PER_LONG - 1)) : 0;
173 	else if (addr == (addr_t) &dummy->starting_addr)
174 		/* Start address of the user specified per set. */
175 		return child->thread.per_user.start;
176 	else if (addr == (addr_t) &dummy->ending_addr)
177 		/* End address of the user specified per set. */
178 		return child->thread.per_user.end;
179 	else if (addr == (addr_t) &dummy->perc_atmid)
180 		/* PER code, ATMID and AI of the last PER trap */
181 		return (unsigned long)
182 			child->thread.per_event.cause << (BITS_PER_LONG - 16);
183 	else if (addr == (addr_t) &dummy->address)
184 		/* Address of the last PER trap */
185 		return child->thread.per_event.address;
186 	else if (addr == (addr_t) &dummy->access_id)
187 		/* Access id of the last PER trap */
188 		return (unsigned long)
189 			child->thread.per_event.paid << (BITS_PER_LONG - 8);
190 	return 0;
191 }
192 
193 /*
194  * Read the word at offset addr from the user area of a process. The
195  * trouble here is that the information is littered over different
196  * locations. The process registers are found on the kernel stack,
197  * the floating point stuff and the trace settings are stored in
198  * the task structure. In addition the different structures in
199  * struct user contain pad bytes that should be read as zeroes.
200  * Lovely...
201  */
202 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
203 {
204 	struct user *dummy = NULL;
205 	addr_t offset, tmp;
206 
207 	if (addr < (addr_t) &dummy->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 == (addr_t) &dummy->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 < (addr_t) &dummy->regs.orig_gpr2) {
219 		/*
220 		 * access registers are stored in the thread structure
221 		 */
222 		offset = addr - (addr_t) &dummy->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 == (addr_t) &dummy->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 == (addr_t) &dummy->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 < (addr_t) &dummy->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 == (addr_t) &dummy->regs.fp_regs.fpc) {
247 		/*
248 		 * floating point control reg. is in the thread structure
249 		 */
250 		tmp = child->thread.fpu.fpc;
251 		tmp <<= BITS_PER_LONG - 32;
252 
253 	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
254 		/*
255 		 * floating point regs. are either in child->thread.fpu
256 		 * or the child->thread.fpu.vxrs array
257 		 */
258 		offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
259 		if (MACHINE_HAS_VX)
260 			tmp = *(addr_t *)
261 			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
262 		else
263 			tmp = *(addr_t *)
264 			       ((addr_t) child->thread.fpu.fprs + offset);
265 
266 	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
267 		/*
268 		 * Handle access to the per_info structure.
269 		 */
270 		addr -= (addr_t) &dummy->regs.per_info;
271 		tmp = __peek_user_per(child, addr);
272 
273 	} else
274 		tmp = 0;
275 
276 	return tmp;
277 }
278 
279 static int
280 peek_user(struct task_struct *child, addr_t addr, addr_t data)
281 {
282 	addr_t tmp, mask;
283 
284 	/*
285 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
286 	 * an alignment of 4. Programmers from hell...
287 	 */
288 	mask = __ADDR_MASK;
289 	if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
290 	    addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
291 		mask = 3;
292 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
293 		return -EIO;
294 
295 	tmp = __peek_user(child, addr);
296 	return put_user(tmp, (addr_t __user *) data);
297 }
298 
299 static inline void __poke_user_per(struct task_struct *child,
300 				   addr_t addr, addr_t data)
301 {
302 	struct per_struct_kernel *dummy = NULL;
303 
304 	/*
305 	 * There are only three fields in the per_info struct that the
306 	 * debugger user can write to.
307 	 * 1) cr9: the debugger wants to set a new PER event mask
308 	 * 2) starting_addr: the debugger wants to set a new starting
309 	 *    address to use with the PER event mask.
310 	 * 3) ending_addr: the debugger wants to set a new ending
311 	 *    address to use with the PER event mask.
312 	 * The user specified PER event mask and the start and end
313 	 * addresses are used only if single stepping is not in effect.
314 	 * Writes to any other field in per_info are ignored.
315 	 */
316 	if (addr == (addr_t) &dummy->cr9)
317 		/* PER event mask of the user specified per set. */
318 		child->thread.per_user.control =
319 			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
320 	else if (addr == (addr_t) &dummy->starting_addr)
321 		/* Starting address of the user specified per set. */
322 		child->thread.per_user.start = data;
323 	else if (addr == (addr_t) &dummy->ending_addr)
324 		/* Ending address of the user specified per set. */
325 		child->thread.per_user.end = data;
326 }
327 
328 /*
329  * Write a word to the user area of a process at location addr. This
330  * operation does have an additional problem compared to peek_user.
331  * Stores to the program status word and on the floating point
332  * control register needs to get checked for validity.
333  */
334 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
335 {
336 	struct user *dummy = NULL;
337 	addr_t offset;
338 
339 	if (addr < (addr_t) &dummy->regs.acrs) {
340 		/*
341 		 * psw and gprs are stored on the stack
342 		 */
343 		if (addr == (addr_t) &dummy->regs.psw.mask) {
344 			unsigned long mask = PSW_MASK_USER;
345 
346 			mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
347 			if ((data ^ PSW_USER_BITS) & ~mask)
348 				/* Invalid psw mask. */
349 				return -EINVAL;
350 			if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
351 				/* Invalid address-space-control bits */
352 				return -EINVAL;
353 			if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
354 				/* Invalid addressing mode bits */
355 				return -EINVAL;
356 		}
357 		*(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
358 
359 	} else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
360 		/*
361 		 * access registers are stored in the thread structure
362 		 */
363 		offset = addr - (addr_t) &dummy->regs.acrs;
364 		/*
365 		 * Very special case: old & broken 64 bit gdb writing
366 		 * to acrs[15] with a 64 bit value. Ignore the lower
367 		 * half of the value and write the upper 32 bit to
368 		 * acrs[15]. Sick...
369 		 */
370 		if (addr == (addr_t) &dummy->regs.acrs[15])
371 			child->thread.acrs[15] = (unsigned int) (data >> 32);
372 		else
373 			*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
374 
375 	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
376 		/*
377 		 * orig_gpr2 is stored on the kernel stack
378 		 */
379 		task_pt_regs(child)->orig_gpr2 = data;
380 
381 	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
382 		/*
383 		 * prevent writes of padding hole between
384 		 * orig_gpr2 and fp_regs on s390.
385 		 */
386 		return 0;
387 
388 	} else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
389 		/*
390 		 * floating point control reg. is in the thread structure
391 		 */
392 		if ((unsigned int) data != 0 ||
393 		    test_fp_ctl(data >> (BITS_PER_LONG - 32)))
394 			return -EINVAL;
395 		child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
396 
397 	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
398 		/*
399 		 * floating point regs. are either in child->thread.fpu
400 		 * or the child->thread.fpu.vxrs array
401 		 */
402 		offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
403 		if (MACHINE_HAS_VX)
404 			*(addr_t *)((addr_t)
405 				child->thread.fpu.vxrs + 2*offset) = data;
406 		else
407 			*(addr_t *)((addr_t)
408 				child->thread.fpu.fprs + offset) = data;
409 
410 	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
411 		/*
412 		 * Handle access to the per_info structure.
413 		 */
414 		addr -= (addr_t) &dummy->regs.per_info;
415 		__poke_user_per(child, addr, data);
416 
417 	}
418 
419 	return 0;
420 }
421 
422 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
423 {
424 	addr_t mask;
425 
426 	/*
427 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
428 	 * an alignment of 4. Programmers from hell indeed...
429 	 */
430 	mask = __ADDR_MASK;
431 	if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
432 	    addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
433 		mask = 3;
434 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
435 		return -EIO;
436 
437 	return __poke_user(child, addr, data);
438 }
439 
440 long arch_ptrace(struct task_struct *child, long request,
441 		 unsigned long addr, unsigned long data)
442 {
443 	ptrace_area parea;
444 	int copied, ret;
445 
446 	switch (request) {
447 	case PTRACE_PEEKUSR:
448 		/* read the word at location addr in the USER area. */
449 		return peek_user(child, addr, data);
450 
451 	case PTRACE_POKEUSR:
452 		/* write the word at location addr in the USER area */
453 		return poke_user(child, addr, data);
454 
455 	case PTRACE_PEEKUSR_AREA:
456 	case PTRACE_POKEUSR_AREA:
457 		if (copy_from_user(&parea, (void __force __user *) addr,
458 							sizeof(parea)))
459 			return -EFAULT;
460 		addr = parea.kernel_addr;
461 		data = parea.process_addr;
462 		copied = 0;
463 		while (copied < parea.len) {
464 			if (request == PTRACE_PEEKUSR_AREA)
465 				ret = peek_user(child, addr, data);
466 			else {
467 				addr_t utmp;
468 				if (get_user(utmp,
469 					     (addr_t __force __user *) data))
470 					return -EFAULT;
471 				ret = poke_user(child, addr, utmp);
472 			}
473 			if (ret)
474 				return ret;
475 			addr += sizeof(unsigned long);
476 			data += sizeof(unsigned long);
477 			copied += sizeof(unsigned long);
478 		}
479 		return 0;
480 	case PTRACE_GET_LAST_BREAK:
481 		put_user(child->thread.last_break,
482 			 (unsigned long __user *) data);
483 		return 0;
484 	case PTRACE_ENABLE_TE:
485 		if (!MACHINE_HAS_TE)
486 			return -EIO;
487 		child->thread.per_flags &= ~PER_FLAG_NO_TE;
488 		return 0;
489 	case PTRACE_DISABLE_TE:
490 		if (!MACHINE_HAS_TE)
491 			return -EIO;
492 		child->thread.per_flags |= PER_FLAG_NO_TE;
493 		child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
494 		return 0;
495 	case PTRACE_TE_ABORT_RAND:
496 		if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
497 			return -EIO;
498 		switch (data) {
499 		case 0UL:
500 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
501 			break;
502 		case 1UL:
503 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
504 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
505 			break;
506 		case 2UL:
507 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
508 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
509 			break;
510 		default:
511 			return -EINVAL;
512 		}
513 		return 0;
514 	default:
515 		return ptrace_request(child, request, addr, data);
516 	}
517 }
518 
519 #ifdef CONFIG_COMPAT
520 /*
521  * Now the fun part starts... a 31 bit program running in the
522  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
523  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
524  * to handle, the difference to the 64 bit versions of the requests
525  * is that the access is done in multiples of 4 byte instead of
526  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
527  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
528  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
529  * is a 31 bit program too, the content of struct user can be
530  * emulated. A 31 bit program peeking into the struct user of
531  * a 64 bit program is a no-no.
532  */
533 
534 /*
535  * Same as peek_user_per but for a 31 bit program.
536  */
537 static inline __u32 __peek_user_per_compat(struct task_struct *child,
538 					   addr_t addr)
539 {
540 	struct compat_per_struct_kernel *dummy32 = NULL;
541 
542 	if (addr == (addr_t) &dummy32->cr9)
543 		/* Control bits of the active per set. */
544 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
545 			PER_EVENT_IFETCH : child->thread.per_user.control;
546 	else if (addr == (addr_t) &dummy32->cr10)
547 		/* Start address of the active per set. */
548 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
549 			0 : child->thread.per_user.start;
550 	else if (addr == (addr_t) &dummy32->cr11)
551 		/* End address of the active per set. */
552 		return test_thread_flag(TIF_SINGLE_STEP) ?
553 			PSW32_ADDR_INSN : child->thread.per_user.end;
554 	else if (addr == (addr_t) &dummy32->bits)
555 		/* Single-step bit. */
556 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
557 			0x80000000 : 0;
558 	else if (addr == (addr_t) &dummy32->starting_addr)
559 		/* Start address of the user specified per set. */
560 		return (__u32) child->thread.per_user.start;
561 	else if (addr == (addr_t) &dummy32->ending_addr)
562 		/* End address of the user specified per set. */
563 		return (__u32) child->thread.per_user.end;
564 	else if (addr == (addr_t) &dummy32->perc_atmid)
565 		/* PER code, ATMID and AI of the last PER trap */
566 		return (__u32) child->thread.per_event.cause << 16;
567 	else if (addr == (addr_t) &dummy32->address)
568 		/* Address of the last PER trap */
569 		return (__u32) child->thread.per_event.address;
570 	else if (addr == (addr_t) &dummy32->access_id)
571 		/* Access id of the last PER trap */
572 		return (__u32) child->thread.per_event.paid << 24;
573 	return 0;
574 }
575 
576 /*
577  * Same as peek_user but for a 31 bit program.
578  */
579 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
580 {
581 	struct compat_user *dummy32 = NULL;
582 	addr_t offset;
583 	__u32 tmp;
584 
585 	if (addr < (addr_t) &dummy32->regs.acrs) {
586 		struct pt_regs *regs = task_pt_regs(child);
587 		/*
588 		 * psw and gprs are stored on the stack
589 		 */
590 		if (addr == (addr_t) &dummy32->regs.psw.mask) {
591 			/* Fake a 31 bit psw mask. */
592 			tmp = (__u32)(regs->psw.mask >> 32);
593 			tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
594 			tmp |= PSW32_USER_BITS;
595 		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
596 			/* Fake a 31 bit psw address. */
597 			tmp = (__u32) regs->psw.addr |
598 				(__u32)(regs->psw.mask & PSW_MASK_BA);
599 		} else {
600 			/* gpr 0-15 */
601 			tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
602 		}
603 	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
604 		/*
605 		 * access registers are stored in the thread structure
606 		 */
607 		offset = addr - (addr_t) &dummy32->regs.acrs;
608 		tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
609 
610 	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
611 		/*
612 		 * orig_gpr2 is stored on the kernel stack
613 		 */
614 		tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
615 
616 	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
617 		/*
618 		 * prevent reads of padding hole between
619 		 * orig_gpr2 and fp_regs on s390.
620 		 */
621 		tmp = 0;
622 
623 	} else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
624 		/*
625 		 * floating point control reg. is in the thread structure
626 		 */
627 		tmp = child->thread.fpu.fpc;
628 
629 	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
630 		/*
631 		 * floating point regs. are either in child->thread.fpu
632 		 * or the child->thread.fpu.vxrs array
633 		 */
634 		offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
635 		if (MACHINE_HAS_VX)
636 			tmp = *(__u32 *)
637 			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
638 		else
639 			tmp = *(__u32 *)
640 			       ((addr_t) child->thread.fpu.fprs + offset);
641 
642 	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
643 		/*
644 		 * Handle access to the per_info structure.
645 		 */
646 		addr -= (addr_t) &dummy32->regs.per_info;
647 		tmp = __peek_user_per_compat(child, addr);
648 
649 	} else
650 		tmp = 0;
651 
652 	return tmp;
653 }
654 
655 static int peek_user_compat(struct task_struct *child,
656 			    addr_t addr, addr_t data)
657 {
658 	__u32 tmp;
659 
660 	if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
661 		return -EIO;
662 
663 	tmp = __peek_user_compat(child, addr);
664 	return put_user(tmp, (__u32 __user *) data);
665 }
666 
667 /*
668  * Same as poke_user_per but for a 31 bit program.
669  */
670 static inline void __poke_user_per_compat(struct task_struct *child,
671 					  addr_t addr, __u32 data)
672 {
673 	struct compat_per_struct_kernel *dummy32 = NULL;
674 
675 	if (addr == (addr_t) &dummy32->cr9)
676 		/* PER event mask of the user specified per set. */
677 		child->thread.per_user.control =
678 			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
679 	else if (addr == (addr_t) &dummy32->starting_addr)
680 		/* Starting address of the user specified per set. */
681 		child->thread.per_user.start = data;
682 	else if (addr == (addr_t) &dummy32->ending_addr)
683 		/* Ending address of the user specified per set. */
684 		child->thread.per_user.end = data;
685 }
686 
687 /*
688  * Same as poke_user but for a 31 bit program.
689  */
690 static int __poke_user_compat(struct task_struct *child,
691 			      addr_t addr, addr_t data)
692 {
693 	struct compat_user *dummy32 = NULL;
694 	__u32 tmp = (__u32) data;
695 	addr_t offset;
696 
697 	if (addr < (addr_t) &dummy32->regs.acrs) {
698 		struct pt_regs *regs = task_pt_regs(child);
699 		/*
700 		 * psw, gprs, acrs and orig_gpr2 are stored on the stack
701 		 */
702 		if (addr == (addr_t) &dummy32->regs.psw.mask) {
703 			__u32 mask = PSW32_MASK_USER;
704 
705 			mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
706 			/* Build a 64 bit psw mask from 31 bit mask. */
707 			if ((tmp ^ PSW32_USER_BITS) & ~mask)
708 				/* Invalid psw mask. */
709 				return -EINVAL;
710 			if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
711 				/* Invalid address-space-control bits */
712 				return -EINVAL;
713 			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
714 				(regs->psw.mask & PSW_MASK_BA) |
715 				(__u64)(tmp & mask) << 32;
716 		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
717 			/* Build a 64 bit psw address from 31 bit address. */
718 			regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
719 			/* Transfer 31 bit amode bit to psw mask. */
720 			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
721 				(__u64)(tmp & PSW32_ADDR_AMODE);
722 		} else {
723 			/* gpr 0-15 */
724 			*(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
725 		}
726 	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
727 		/*
728 		 * access registers are stored in the thread structure
729 		 */
730 		offset = addr - (addr_t) &dummy32->regs.acrs;
731 		*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
732 
733 	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
734 		/*
735 		 * orig_gpr2 is stored on the kernel stack
736 		 */
737 		*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
738 
739 	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
740 		/*
741 		 * prevent writess of padding hole between
742 		 * orig_gpr2 and fp_regs on s390.
743 		 */
744 		return 0;
745 
746 	} else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
747 		/*
748 		 * floating point control reg. is in the thread structure
749 		 */
750 		if (test_fp_ctl(tmp))
751 			return -EINVAL;
752 		child->thread.fpu.fpc = data;
753 
754 	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
755 		/*
756 		 * floating point regs. are either in child->thread.fpu
757 		 * or the child->thread.fpu.vxrs array
758 		 */
759 		offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
760 		if (MACHINE_HAS_VX)
761 			*(__u32 *)((addr_t)
762 				child->thread.fpu.vxrs + 2*offset) = tmp;
763 		else
764 			*(__u32 *)((addr_t)
765 				child->thread.fpu.fprs + offset) = tmp;
766 
767 	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
768 		/*
769 		 * Handle access to the per_info structure.
770 		 */
771 		addr -= (addr_t) &dummy32->regs.per_info;
772 		__poke_user_per_compat(child, addr, data);
773 	}
774 
775 	return 0;
776 }
777 
778 static int poke_user_compat(struct task_struct *child,
779 			    addr_t addr, addr_t data)
780 {
781 	if (!is_compat_task() || (addr & 3) ||
782 	    addr > sizeof(struct compat_user) - 3)
783 		return -EIO;
784 
785 	return __poke_user_compat(child, addr, data);
786 }
787 
788 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
789 			compat_ulong_t caddr, compat_ulong_t cdata)
790 {
791 	unsigned long addr = caddr;
792 	unsigned long data = cdata;
793 	compat_ptrace_area parea;
794 	int copied, ret;
795 
796 	switch (request) {
797 	case PTRACE_PEEKUSR:
798 		/* read the word at location addr in the USER area. */
799 		return peek_user_compat(child, addr, data);
800 
801 	case PTRACE_POKEUSR:
802 		/* write the word at location addr in the USER area */
803 		return poke_user_compat(child, addr, data);
804 
805 	case PTRACE_PEEKUSR_AREA:
806 	case PTRACE_POKEUSR_AREA:
807 		if (copy_from_user(&parea, (void __force __user *) addr,
808 							sizeof(parea)))
809 			return -EFAULT;
810 		addr = parea.kernel_addr;
811 		data = parea.process_addr;
812 		copied = 0;
813 		while (copied < parea.len) {
814 			if (request == PTRACE_PEEKUSR_AREA)
815 				ret = peek_user_compat(child, addr, data);
816 			else {
817 				__u32 utmp;
818 				if (get_user(utmp,
819 					     (__u32 __force __user *) data))
820 					return -EFAULT;
821 				ret = poke_user_compat(child, addr, utmp);
822 			}
823 			if (ret)
824 				return ret;
825 			addr += sizeof(unsigned int);
826 			data += sizeof(unsigned int);
827 			copied += sizeof(unsigned int);
828 		}
829 		return 0;
830 	case PTRACE_GET_LAST_BREAK:
831 		put_user(child->thread.last_break,
832 			 (unsigned int __user *) data);
833 		return 0;
834 	}
835 	return compat_ptrace_request(child, request, addr, data);
836 }
837 #endif
838 
839 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
840 {
841 	unsigned long mask = -1UL;
842 
843 	/*
844 	 * The sysc_tracesys code in entry.S stored the system
845 	 * call number to gprs[2].
846 	 */
847 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
848 	    (tracehook_report_syscall_entry(regs) ||
849 	     regs->gprs[2] >= NR_syscalls)) {
850 		/*
851 		 * Tracing decided this syscall should not happen or the
852 		 * debugger stored an invalid system call number. Skip
853 		 * the system call and the system call restart handling.
854 		 */
855 		clear_pt_regs_flag(regs, PIF_SYSCALL);
856 		return -1;
857 	}
858 
859 	/* Do the secure computing check after ptrace. */
860 	if (secure_computing(NULL)) {
861 		/* seccomp failures shouldn't expose any additional code. */
862 		return -1;
863 	}
864 
865 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
866 		trace_sys_enter(regs, regs->gprs[2]);
867 
868 	if (is_compat_task())
869 		mask = 0xffffffff;
870 
871 	audit_syscall_entry(regs->gprs[2], regs->orig_gpr2 & mask,
872 			    regs->gprs[3] &mask, regs->gprs[4] &mask,
873 			    regs->gprs[5] &mask);
874 
875 	return regs->gprs[2];
876 }
877 
878 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
879 {
880 	audit_syscall_exit(regs);
881 
882 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
883 		trace_sys_exit(regs, regs->gprs[2]);
884 
885 	if (test_thread_flag(TIF_SYSCALL_TRACE))
886 		tracehook_report_syscall_exit(regs, 0);
887 }
888 
889 /*
890  * user_regset definitions.
891  */
892 
893 static int s390_regs_get(struct task_struct *target,
894 			 const struct user_regset *regset,
895 			 unsigned int pos, unsigned int count,
896 			 void *kbuf, void __user *ubuf)
897 {
898 	if (target == current)
899 		save_access_regs(target->thread.acrs);
900 
901 	if (kbuf) {
902 		unsigned long *k = kbuf;
903 		while (count > 0) {
904 			*k++ = __peek_user(target, pos);
905 			count -= sizeof(*k);
906 			pos += sizeof(*k);
907 		}
908 	} else {
909 		unsigned long __user *u = ubuf;
910 		while (count > 0) {
911 			if (__put_user(__peek_user(target, pos), u++))
912 				return -EFAULT;
913 			count -= sizeof(*u);
914 			pos += sizeof(*u);
915 		}
916 	}
917 	return 0;
918 }
919 
920 static int s390_regs_set(struct task_struct *target,
921 			 const struct user_regset *regset,
922 			 unsigned int pos, unsigned int count,
923 			 const void *kbuf, const void __user *ubuf)
924 {
925 	int rc = 0;
926 
927 	if (target == current)
928 		save_access_regs(target->thread.acrs);
929 
930 	if (kbuf) {
931 		const unsigned long *k = kbuf;
932 		while (count > 0 && !rc) {
933 			rc = __poke_user(target, pos, *k++);
934 			count -= sizeof(*k);
935 			pos += sizeof(*k);
936 		}
937 	} else {
938 		const unsigned long  __user *u = ubuf;
939 		while (count > 0 && !rc) {
940 			unsigned long word;
941 			rc = __get_user(word, u++);
942 			if (rc)
943 				break;
944 			rc = __poke_user(target, pos, word);
945 			count -= sizeof(*u);
946 			pos += sizeof(*u);
947 		}
948 	}
949 
950 	if (rc == 0 && target == current)
951 		restore_access_regs(target->thread.acrs);
952 
953 	return rc;
954 }
955 
956 static int s390_fpregs_get(struct task_struct *target,
957 			   const struct user_regset *regset, unsigned int pos,
958 			   unsigned int count, void *kbuf, void __user *ubuf)
959 {
960 	_s390_fp_regs fp_regs;
961 
962 	if (target == current)
963 		save_fpu_regs();
964 
965 	fp_regs.fpc = target->thread.fpu.fpc;
966 	fpregs_store(&fp_regs, &target->thread.fpu);
967 
968 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
969 				   &fp_regs, 0, -1);
970 }
971 
972 static int s390_fpregs_set(struct task_struct *target,
973 			   const struct user_regset *regset, unsigned int pos,
974 			   unsigned int count, const void *kbuf,
975 			   const void __user *ubuf)
976 {
977 	int rc = 0;
978 	freg_t fprs[__NUM_FPRS];
979 
980 	if (target == current)
981 		save_fpu_regs();
982 
983 	if (MACHINE_HAS_VX)
984 		convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
985 	else
986 		memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
987 
988 	/* If setting FPC, must validate it first. */
989 	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
990 		u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
991 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
992 					0, offsetof(s390_fp_regs, fprs));
993 		if (rc)
994 			return rc;
995 		if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
996 			return -EINVAL;
997 		target->thread.fpu.fpc = ufpc[0];
998 	}
999 
1000 	if (rc == 0 && count > 0)
1001 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1002 					fprs, offsetof(s390_fp_regs, fprs), -1);
1003 	if (rc)
1004 		return rc;
1005 
1006 	if (MACHINE_HAS_VX)
1007 		convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
1008 	else
1009 		memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
1010 
1011 	return rc;
1012 }
1013 
1014 static int s390_last_break_get(struct task_struct *target,
1015 			       const struct user_regset *regset,
1016 			       unsigned int pos, unsigned int count,
1017 			       void *kbuf, void __user *ubuf)
1018 {
1019 	if (count > 0) {
1020 		if (kbuf) {
1021 			unsigned long *k = kbuf;
1022 			*k = target->thread.last_break;
1023 		} else {
1024 			unsigned long  __user *u = ubuf;
1025 			if (__put_user(target->thread.last_break, u))
1026 				return -EFAULT;
1027 		}
1028 	}
1029 	return 0;
1030 }
1031 
1032 static int s390_last_break_set(struct task_struct *target,
1033 			       const struct user_regset *regset,
1034 			       unsigned int pos, unsigned int count,
1035 			       const void *kbuf, const void __user *ubuf)
1036 {
1037 	return 0;
1038 }
1039 
1040 static int s390_tdb_get(struct task_struct *target,
1041 			const struct user_regset *regset,
1042 			unsigned int pos, unsigned int count,
1043 			void *kbuf, void __user *ubuf)
1044 {
1045 	struct pt_regs *regs = task_pt_regs(target);
1046 	unsigned char *data;
1047 
1048 	if (!(regs->int_code & 0x200))
1049 		return -ENODATA;
1050 	data = target->thread.trap_tdb;
1051 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
1052 }
1053 
1054 static int s390_tdb_set(struct task_struct *target,
1055 			const struct user_regset *regset,
1056 			unsigned int pos, unsigned int count,
1057 			const void *kbuf, const void __user *ubuf)
1058 {
1059 	return 0;
1060 }
1061 
1062 static int s390_vxrs_low_get(struct task_struct *target,
1063 			     const struct user_regset *regset,
1064 			     unsigned int pos, unsigned int count,
1065 			     void *kbuf, void __user *ubuf)
1066 {
1067 	__u64 vxrs[__NUM_VXRS_LOW];
1068 	int i;
1069 
1070 	if (!MACHINE_HAS_VX)
1071 		return -ENODEV;
1072 	if (target == current)
1073 		save_fpu_regs();
1074 	for (i = 0; i < __NUM_VXRS_LOW; i++)
1075 		vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1076 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1077 }
1078 
1079 static int s390_vxrs_low_set(struct task_struct *target,
1080 			     const struct user_regset *regset,
1081 			     unsigned int pos, unsigned int count,
1082 			     const void *kbuf, const void __user *ubuf)
1083 {
1084 	__u64 vxrs[__NUM_VXRS_LOW];
1085 	int i, rc;
1086 
1087 	if (!MACHINE_HAS_VX)
1088 		return -ENODEV;
1089 	if (target == current)
1090 		save_fpu_regs();
1091 
1092 	for (i = 0; i < __NUM_VXRS_LOW; i++)
1093 		vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1094 
1095 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1096 	if (rc == 0)
1097 		for (i = 0; i < __NUM_VXRS_LOW; i++)
1098 			*((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1099 
1100 	return rc;
1101 }
1102 
1103 static int s390_vxrs_high_get(struct task_struct *target,
1104 			      const struct user_regset *regset,
1105 			      unsigned int pos, unsigned int count,
1106 			      void *kbuf, void __user *ubuf)
1107 {
1108 	__vector128 vxrs[__NUM_VXRS_HIGH];
1109 
1110 	if (!MACHINE_HAS_VX)
1111 		return -ENODEV;
1112 	if (target == current)
1113 		save_fpu_regs();
1114 	memcpy(vxrs, target->thread.fpu.vxrs + __NUM_VXRS_LOW, sizeof(vxrs));
1115 
1116 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1117 }
1118 
1119 static int s390_vxrs_high_set(struct task_struct *target,
1120 			      const struct user_regset *regset,
1121 			      unsigned int pos, unsigned int count,
1122 			      const void *kbuf, const void __user *ubuf)
1123 {
1124 	int rc;
1125 
1126 	if (!MACHINE_HAS_VX)
1127 		return -ENODEV;
1128 	if (target == current)
1129 		save_fpu_regs();
1130 
1131 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1132 				target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1133 	return rc;
1134 }
1135 
1136 static int s390_system_call_get(struct task_struct *target,
1137 				const struct user_regset *regset,
1138 				unsigned int pos, unsigned int count,
1139 				void *kbuf, void __user *ubuf)
1140 {
1141 	unsigned int *data = &target->thread.system_call;
1142 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1143 				   data, 0, sizeof(unsigned int));
1144 }
1145 
1146 static int s390_system_call_set(struct task_struct *target,
1147 				const struct user_regset *regset,
1148 				unsigned int pos, unsigned int count,
1149 				const void *kbuf, const void __user *ubuf)
1150 {
1151 	unsigned int *data = &target->thread.system_call;
1152 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1153 				  data, 0, sizeof(unsigned int));
1154 }
1155 
1156 static int s390_gs_cb_get(struct task_struct *target,
1157 			  const struct user_regset *regset,
1158 			  unsigned int pos, unsigned int count,
1159 			  void *kbuf, void __user *ubuf)
1160 {
1161 	struct gs_cb *data = target->thread.gs_cb;
1162 
1163 	if (!MACHINE_HAS_GS)
1164 		return -ENODEV;
1165 	if (!data)
1166 		return -ENODATA;
1167 	if (target == current)
1168 		save_gs_cb(data);
1169 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1170 				   data, 0, sizeof(struct gs_cb));
1171 }
1172 
1173 static int s390_gs_cb_set(struct task_struct *target,
1174 			  const struct user_regset *regset,
1175 			  unsigned int pos, unsigned int count,
1176 			  const void *kbuf, const void __user *ubuf)
1177 {
1178 	struct gs_cb gs_cb = { }, *data = NULL;
1179 	int rc;
1180 
1181 	if (!MACHINE_HAS_GS)
1182 		return -ENODEV;
1183 	if (!target->thread.gs_cb) {
1184 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1185 		if (!data)
1186 			return -ENOMEM;
1187 	}
1188 	if (!target->thread.gs_cb)
1189 		gs_cb.gsd = 25;
1190 	else if (target == current)
1191 		save_gs_cb(&gs_cb);
1192 	else
1193 		gs_cb = *target->thread.gs_cb;
1194 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1195 				&gs_cb, 0, sizeof(gs_cb));
1196 	if (rc) {
1197 		kfree(data);
1198 		return -EFAULT;
1199 	}
1200 	preempt_disable();
1201 	if (!target->thread.gs_cb)
1202 		target->thread.gs_cb = data;
1203 	*target->thread.gs_cb = gs_cb;
1204 	if (target == current) {
1205 		__ctl_set_bit(2, 4);
1206 		restore_gs_cb(target->thread.gs_cb);
1207 	}
1208 	preempt_enable();
1209 	return rc;
1210 }
1211 
1212 static int s390_gs_bc_get(struct task_struct *target,
1213 			  const struct user_regset *regset,
1214 			  unsigned int pos, unsigned int count,
1215 			  void *kbuf, void __user *ubuf)
1216 {
1217 	struct gs_cb *data = target->thread.gs_bc_cb;
1218 
1219 	if (!MACHINE_HAS_GS)
1220 		return -ENODEV;
1221 	if (!data)
1222 		return -ENODATA;
1223 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1224 				   data, 0, sizeof(struct gs_cb));
1225 }
1226 
1227 static int s390_gs_bc_set(struct task_struct *target,
1228 			  const struct user_regset *regset,
1229 			  unsigned int pos, unsigned int count,
1230 			  const void *kbuf, const void __user *ubuf)
1231 {
1232 	struct gs_cb *data = target->thread.gs_bc_cb;
1233 
1234 	if (!MACHINE_HAS_GS)
1235 		return -ENODEV;
1236 	if (!data) {
1237 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1238 		if (!data)
1239 			return -ENOMEM;
1240 		target->thread.gs_bc_cb = data;
1241 	}
1242 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1243 				  data, 0, sizeof(struct gs_cb));
1244 }
1245 
1246 static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1247 {
1248 	return (cb->rca & 0x1f) == 0 &&
1249 		(cb->roa & 0xfff) == 0 &&
1250 		(cb->rla & 0xfff) == 0xfff &&
1251 		cb->s == 1 &&
1252 		cb->k == 1 &&
1253 		cb->h == 0 &&
1254 		cb->reserved1 == 0 &&
1255 		cb->ps == 1 &&
1256 		cb->qs == 0 &&
1257 		cb->pc == 1 &&
1258 		cb->qc == 0 &&
1259 		cb->reserved2 == 0 &&
1260 		cb->key == PAGE_DEFAULT_KEY &&
1261 		cb->reserved3 == 0 &&
1262 		cb->reserved4 == 0 &&
1263 		cb->reserved5 == 0 &&
1264 		cb->reserved6 == 0 &&
1265 		cb->reserved7 == 0 &&
1266 		cb->reserved8 == 0 &&
1267 		cb->rla >= cb->roa &&
1268 		cb->rca >= cb->roa &&
1269 		cb->rca <= cb->rla+1 &&
1270 		cb->m < 3;
1271 }
1272 
1273 static int s390_runtime_instr_get(struct task_struct *target,
1274 				const struct user_regset *regset,
1275 				unsigned int pos, unsigned int count,
1276 				void *kbuf, void __user *ubuf)
1277 {
1278 	struct runtime_instr_cb *data = target->thread.ri_cb;
1279 
1280 	if (!test_facility(64))
1281 		return -ENODEV;
1282 	if (!data)
1283 		return -ENODATA;
1284 
1285 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1286 				   data, 0, sizeof(struct runtime_instr_cb));
1287 }
1288 
1289 static int s390_runtime_instr_set(struct task_struct *target,
1290 				  const struct user_regset *regset,
1291 				  unsigned int pos, unsigned int count,
1292 				  const void *kbuf, const void __user *ubuf)
1293 {
1294 	struct runtime_instr_cb ri_cb = { }, *data = NULL;
1295 	int rc;
1296 
1297 	if (!test_facility(64))
1298 		return -ENODEV;
1299 
1300 	if (!target->thread.ri_cb) {
1301 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1302 		if (!data)
1303 			return -ENOMEM;
1304 	}
1305 
1306 	if (target->thread.ri_cb) {
1307 		if (target == current)
1308 			store_runtime_instr_cb(&ri_cb);
1309 		else
1310 			ri_cb = *target->thread.ri_cb;
1311 	}
1312 
1313 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1314 				&ri_cb, 0, sizeof(struct runtime_instr_cb));
1315 	if (rc) {
1316 		kfree(data);
1317 		return -EFAULT;
1318 	}
1319 
1320 	if (!is_ri_cb_valid(&ri_cb)) {
1321 		kfree(data);
1322 		return -EINVAL;
1323 	}
1324 
1325 	preempt_disable();
1326 	if (!target->thread.ri_cb)
1327 		target->thread.ri_cb = data;
1328 	*target->thread.ri_cb = ri_cb;
1329 	if (target == current)
1330 		load_runtime_instr_cb(target->thread.ri_cb);
1331 	preempt_enable();
1332 
1333 	return 0;
1334 }
1335 
1336 static const struct user_regset s390_regsets[] = {
1337 	{
1338 		.core_note_type = NT_PRSTATUS,
1339 		.n = sizeof(s390_regs) / sizeof(long),
1340 		.size = sizeof(long),
1341 		.align = sizeof(long),
1342 		.get = s390_regs_get,
1343 		.set = s390_regs_set,
1344 	},
1345 	{
1346 		.core_note_type = NT_PRFPREG,
1347 		.n = sizeof(s390_fp_regs) / sizeof(long),
1348 		.size = sizeof(long),
1349 		.align = sizeof(long),
1350 		.get = s390_fpregs_get,
1351 		.set = s390_fpregs_set,
1352 	},
1353 	{
1354 		.core_note_type = NT_S390_SYSTEM_CALL,
1355 		.n = 1,
1356 		.size = sizeof(unsigned int),
1357 		.align = sizeof(unsigned int),
1358 		.get = s390_system_call_get,
1359 		.set = s390_system_call_set,
1360 	},
1361 	{
1362 		.core_note_type = NT_S390_LAST_BREAK,
1363 		.n = 1,
1364 		.size = sizeof(long),
1365 		.align = sizeof(long),
1366 		.get = s390_last_break_get,
1367 		.set = s390_last_break_set,
1368 	},
1369 	{
1370 		.core_note_type = NT_S390_TDB,
1371 		.n = 1,
1372 		.size = 256,
1373 		.align = 1,
1374 		.get = s390_tdb_get,
1375 		.set = s390_tdb_set,
1376 	},
1377 	{
1378 		.core_note_type = NT_S390_VXRS_LOW,
1379 		.n = __NUM_VXRS_LOW,
1380 		.size = sizeof(__u64),
1381 		.align = sizeof(__u64),
1382 		.get = s390_vxrs_low_get,
1383 		.set = s390_vxrs_low_set,
1384 	},
1385 	{
1386 		.core_note_type = NT_S390_VXRS_HIGH,
1387 		.n = __NUM_VXRS_HIGH,
1388 		.size = sizeof(__vector128),
1389 		.align = sizeof(__vector128),
1390 		.get = s390_vxrs_high_get,
1391 		.set = s390_vxrs_high_set,
1392 	},
1393 	{
1394 		.core_note_type = NT_S390_GS_CB,
1395 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1396 		.size = sizeof(__u64),
1397 		.align = sizeof(__u64),
1398 		.get = s390_gs_cb_get,
1399 		.set = s390_gs_cb_set,
1400 	},
1401 	{
1402 		.core_note_type = NT_S390_GS_BC,
1403 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1404 		.size = sizeof(__u64),
1405 		.align = sizeof(__u64),
1406 		.get = s390_gs_bc_get,
1407 		.set = s390_gs_bc_set,
1408 	},
1409 	{
1410 		.core_note_type = NT_S390_RI_CB,
1411 		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1412 		.size = sizeof(__u64),
1413 		.align = sizeof(__u64),
1414 		.get = s390_runtime_instr_get,
1415 		.set = s390_runtime_instr_set,
1416 	},
1417 };
1418 
1419 static const struct user_regset_view user_s390_view = {
1420 	.name = UTS_MACHINE,
1421 	.e_machine = EM_S390,
1422 	.regsets = s390_regsets,
1423 	.n = ARRAY_SIZE(s390_regsets)
1424 };
1425 
1426 #ifdef CONFIG_COMPAT
1427 static int s390_compat_regs_get(struct task_struct *target,
1428 				const struct user_regset *regset,
1429 				unsigned int pos, unsigned int count,
1430 				void *kbuf, void __user *ubuf)
1431 {
1432 	if (target == current)
1433 		save_access_regs(target->thread.acrs);
1434 
1435 	if (kbuf) {
1436 		compat_ulong_t *k = kbuf;
1437 		while (count > 0) {
1438 			*k++ = __peek_user_compat(target, pos);
1439 			count -= sizeof(*k);
1440 			pos += sizeof(*k);
1441 		}
1442 	} else {
1443 		compat_ulong_t __user *u = ubuf;
1444 		while (count > 0) {
1445 			if (__put_user(__peek_user_compat(target, pos), u++))
1446 				return -EFAULT;
1447 			count -= sizeof(*u);
1448 			pos += sizeof(*u);
1449 		}
1450 	}
1451 	return 0;
1452 }
1453 
1454 static int s390_compat_regs_set(struct task_struct *target,
1455 				const struct user_regset *regset,
1456 				unsigned int pos, unsigned int count,
1457 				const void *kbuf, const void __user *ubuf)
1458 {
1459 	int rc = 0;
1460 
1461 	if (target == current)
1462 		save_access_regs(target->thread.acrs);
1463 
1464 	if (kbuf) {
1465 		const compat_ulong_t *k = kbuf;
1466 		while (count > 0 && !rc) {
1467 			rc = __poke_user_compat(target, pos, *k++);
1468 			count -= sizeof(*k);
1469 			pos += sizeof(*k);
1470 		}
1471 	} else {
1472 		const compat_ulong_t  __user *u = ubuf;
1473 		while (count > 0 && !rc) {
1474 			compat_ulong_t word;
1475 			rc = __get_user(word, u++);
1476 			if (rc)
1477 				break;
1478 			rc = __poke_user_compat(target, pos, word);
1479 			count -= sizeof(*u);
1480 			pos += sizeof(*u);
1481 		}
1482 	}
1483 
1484 	if (rc == 0 && target == current)
1485 		restore_access_regs(target->thread.acrs);
1486 
1487 	return rc;
1488 }
1489 
1490 static int s390_compat_regs_high_get(struct task_struct *target,
1491 				     const struct user_regset *regset,
1492 				     unsigned int pos, unsigned int count,
1493 				     void *kbuf, void __user *ubuf)
1494 {
1495 	compat_ulong_t *gprs_high;
1496 
1497 	gprs_high = (compat_ulong_t *)
1498 		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1499 	if (kbuf) {
1500 		compat_ulong_t *k = kbuf;
1501 		while (count > 0) {
1502 			*k++ = *gprs_high;
1503 			gprs_high += 2;
1504 			count -= sizeof(*k);
1505 		}
1506 	} else {
1507 		compat_ulong_t __user *u = ubuf;
1508 		while (count > 0) {
1509 			if (__put_user(*gprs_high, u++))
1510 				return -EFAULT;
1511 			gprs_high += 2;
1512 			count -= sizeof(*u);
1513 		}
1514 	}
1515 	return 0;
1516 }
1517 
1518 static int s390_compat_regs_high_set(struct task_struct *target,
1519 				     const struct user_regset *regset,
1520 				     unsigned int pos, unsigned int count,
1521 				     const void *kbuf, const void __user *ubuf)
1522 {
1523 	compat_ulong_t *gprs_high;
1524 	int rc = 0;
1525 
1526 	gprs_high = (compat_ulong_t *)
1527 		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1528 	if (kbuf) {
1529 		const compat_ulong_t *k = kbuf;
1530 		while (count > 0) {
1531 			*gprs_high = *k++;
1532 			*gprs_high += 2;
1533 			count -= sizeof(*k);
1534 		}
1535 	} else {
1536 		const compat_ulong_t  __user *u = ubuf;
1537 		while (count > 0 && !rc) {
1538 			unsigned long word;
1539 			rc = __get_user(word, u++);
1540 			if (rc)
1541 				break;
1542 			*gprs_high = word;
1543 			*gprs_high += 2;
1544 			count -= sizeof(*u);
1545 		}
1546 	}
1547 
1548 	return rc;
1549 }
1550 
1551 static int s390_compat_last_break_get(struct task_struct *target,
1552 				      const struct user_regset *regset,
1553 				      unsigned int pos, unsigned int count,
1554 				      void *kbuf, void __user *ubuf)
1555 {
1556 	compat_ulong_t last_break;
1557 
1558 	if (count > 0) {
1559 		last_break = target->thread.last_break;
1560 		if (kbuf) {
1561 			unsigned long *k = kbuf;
1562 			*k = last_break;
1563 		} else {
1564 			unsigned long  __user *u = ubuf;
1565 			if (__put_user(last_break, u))
1566 				return -EFAULT;
1567 		}
1568 	}
1569 	return 0;
1570 }
1571 
1572 static int s390_compat_last_break_set(struct task_struct *target,
1573 				      const struct user_regset *regset,
1574 				      unsigned int pos, unsigned int count,
1575 				      const void *kbuf, const void __user *ubuf)
1576 {
1577 	return 0;
1578 }
1579 
1580 static const struct user_regset s390_compat_regsets[] = {
1581 	{
1582 		.core_note_type = NT_PRSTATUS,
1583 		.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1584 		.size = sizeof(compat_long_t),
1585 		.align = sizeof(compat_long_t),
1586 		.get = s390_compat_regs_get,
1587 		.set = s390_compat_regs_set,
1588 	},
1589 	{
1590 		.core_note_type = NT_PRFPREG,
1591 		.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1592 		.size = sizeof(compat_long_t),
1593 		.align = sizeof(compat_long_t),
1594 		.get = s390_fpregs_get,
1595 		.set = s390_fpregs_set,
1596 	},
1597 	{
1598 		.core_note_type = NT_S390_SYSTEM_CALL,
1599 		.n = 1,
1600 		.size = sizeof(compat_uint_t),
1601 		.align = sizeof(compat_uint_t),
1602 		.get = s390_system_call_get,
1603 		.set = s390_system_call_set,
1604 	},
1605 	{
1606 		.core_note_type = NT_S390_LAST_BREAK,
1607 		.n = 1,
1608 		.size = sizeof(long),
1609 		.align = sizeof(long),
1610 		.get = s390_compat_last_break_get,
1611 		.set = s390_compat_last_break_set,
1612 	},
1613 	{
1614 		.core_note_type = NT_S390_TDB,
1615 		.n = 1,
1616 		.size = 256,
1617 		.align = 1,
1618 		.get = s390_tdb_get,
1619 		.set = s390_tdb_set,
1620 	},
1621 	{
1622 		.core_note_type = NT_S390_VXRS_LOW,
1623 		.n = __NUM_VXRS_LOW,
1624 		.size = sizeof(__u64),
1625 		.align = sizeof(__u64),
1626 		.get = s390_vxrs_low_get,
1627 		.set = s390_vxrs_low_set,
1628 	},
1629 	{
1630 		.core_note_type = NT_S390_VXRS_HIGH,
1631 		.n = __NUM_VXRS_HIGH,
1632 		.size = sizeof(__vector128),
1633 		.align = sizeof(__vector128),
1634 		.get = s390_vxrs_high_get,
1635 		.set = s390_vxrs_high_set,
1636 	},
1637 	{
1638 		.core_note_type = NT_S390_HIGH_GPRS,
1639 		.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1640 		.size = sizeof(compat_long_t),
1641 		.align = sizeof(compat_long_t),
1642 		.get = s390_compat_regs_high_get,
1643 		.set = s390_compat_regs_high_set,
1644 	},
1645 	{
1646 		.core_note_type = NT_S390_GS_CB,
1647 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1648 		.size = sizeof(__u64),
1649 		.align = sizeof(__u64),
1650 		.get = s390_gs_cb_get,
1651 		.set = s390_gs_cb_set,
1652 	},
1653 	{
1654 		.core_note_type = NT_S390_GS_BC,
1655 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1656 		.size = sizeof(__u64),
1657 		.align = sizeof(__u64),
1658 		.get = s390_gs_bc_get,
1659 		.set = s390_gs_bc_set,
1660 	},
1661 	{
1662 		.core_note_type = NT_S390_RI_CB,
1663 		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1664 		.size = sizeof(__u64),
1665 		.align = sizeof(__u64),
1666 		.get = s390_runtime_instr_get,
1667 		.set = s390_runtime_instr_set,
1668 	},
1669 };
1670 
1671 static const struct user_regset_view user_s390_compat_view = {
1672 	.name = "s390",
1673 	.e_machine = EM_S390,
1674 	.regsets = s390_compat_regsets,
1675 	.n = ARRAY_SIZE(s390_compat_regsets)
1676 };
1677 #endif
1678 
1679 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1680 {
1681 #ifdef CONFIG_COMPAT
1682 	if (test_tsk_thread_flag(task, TIF_31BIT))
1683 		return &user_s390_compat_view;
1684 #endif
1685 	return &user_s390_view;
1686 }
1687 
1688 static const char *gpr_names[NUM_GPRS] = {
1689 	"r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1690 	"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1691 };
1692 
1693 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1694 {
1695 	if (offset >= NUM_GPRS)
1696 		return 0;
1697 	return regs->gprs[offset];
1698 }
1699 
1700 int regs_query_register_offset(const char *name)
1701 {
1702 	unsigned long offset;
1703 
1704 	if (!name || *name != 'r')
1705 		return -EINVAL;
1706 	if (kstrtoul(name + 1, 10, &offset))
1707 		return -EINVAL;
1708 	if (offset >= NUM_GPRS)
1709 		return -EINVAL;
1710 	return offset;
1711 }
1712 
1713 const char *regs_query_register_name(unsigned int offset)
1714 {
1715 	if (offset >= NUM_GPRS)
1716 		return NULL;
1717 	return gpr_names[offset];
1718 }
1719 
1720 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1721 {
1722 	unsigned long ksp = kernel_stack_pointer(regs);
1723 
1724 	return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1725 }
1726 
1727 /**
1728  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1729  * @regs:pt_regs which contains kernel stack pointer.
1730  * @n:stack entry number.
1731  *
1732  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1733  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1734  * this returns 0.
1735  */
1736 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1737 {
1738 	unsigned long addr;
1739 
1740 	addr = kernel_stack_pointer(regs) + n * sizeof(long);
1741 	if (!regs_within_kernel_stack(regs, addr))
1742 		return 0;
1743 	return *(unsigned long *)addr;
1744 }
1745