xref: /openbmc/linux/arch/s390/kernel/ptrace.c (revision f71a261a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Ptrace user space interface.
4  *
5  *    Copyright IBM Corp. 1999, 2010
6  *    Author(s): Denis Joseph Barrow
7  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
8  */
9 
10 #include "asm/ptrace.h"
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
13 #include <linux/sched/task_stack.h>
14 #include <linux/mm.h>
15 #include <linux/smp.h>
16 #include <linux/errno.h>
17 #include <linux/ptrace.h>
18 #include <linux/user.h>
19 #include <linux/security.h>
20 #include <linux/audit.h>
21 #include <linux/signal.h>
22 #include <linux/elf.h>
23 #include <linux/regset.h>
24 #include <linux/seccomp.h>
25 #include <linux/compat.h>
26 #include <trace/syscall.h>
27 #include <asm/page.h>
28 #include <linux/uaccess.h>
29 #include <asm/unistd.h>
30 #include <asm/switch_to.h>
31 #include <asm/runtime_instr.h>
32 #include <asm/facility.h>
33 
34 #include "entry.h"
35 
36 #ifdef CONFIG_COMPAT
37 #include "compat_ptrace.h"
38 #endif
39 
40 void update_cr_regs(struct task_struct *task)
41 {
42 	struct pt_regs *regs = task_pt_regs(task);
43 	struct thread_struct *thread = &task->thread;
44 	struct per_regs old, new;
45 	union ctlreg0 cr0_old, cr0_new;
46 	union ctlreg2 cr2_old, cr2_new;
47 	int cr0_changed, cr2_changed;
48 
49 	__ctl_store(cr0_old.val, 0, 0);
50 	__ctl_store(cr2_old.val, 2, 2);
51 	cr0_new = cr0_old;
52 	cr2_new = cr2_old;
53 	/* Take care of the enable/disable of transactional execution. */
54 	if (MACHINE_HAS_TE) {
55 		/* Set or clear transaction execution TXC bit 8. */
56 		cr0_new.tcx = 1;
57 		if (task->thread.per_flags & PER_FLAG_NO_TE)
58 			cr0_new.tcx = 0;
59 		/* Set or clear transaction execution TDC bits 62 and 63. */
60 		cr2_new.tdc = 0;
61 		if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
62 			if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
63 				cr2_new.tdc = 1;
64 			else
65 				cr2_new.tdc = 2;
66 		}
67 	}
68 	/* Take care of enable/disable of guarded storage. */
69 	if (MACHINE_HAS_GS) {
70 		cr2_new.gse = 0;
71 		if (task->thread.gs_cb)
72 			cr2_new.gse = 1;
73 	}
74 	/* Load control register 0/2 iff changed */
75 	cr0_changed = cr0_new.val != cr0_old.val;
76 	cr2_changed = cr2_new.val != cr2_old.val;
77 	if (cr0_changed)
78 		__ctl_load(cr0_new.val, 0, 0);
79 	if (cr2_changed)
80 		__ctl_load(cr2_new.val, 2, 2);
81 	/* Copy user specified PER registers */
82 	new.control = thread->per_user.control;
83 	new.start = thread->per_user.start;
84 	new.end = thread->per_user.end;
85 
86 	/* merge TIF_SINGLE_STEP into user specified PER registers. */
87 	if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
88 	    test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
89 		if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
90 			new.control |= PER_EVENT_BRANCH;
91 		else
92 			new.control |= PER_EVENT_IFETCH;
93 		new.control |= PER_CONTROL_SUSPENSION;
94 		new.control |= PER_EVENT_TRANSACTION_END;
95 		if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
96 			new.control |= PER_EVENT_IFETCH;
97 		new.start = 0;
98 		new.end = -1UL;
99 	}
100 
101 	/* Take care of the PER enablement bit in the PSW. */
102 	if (!(new.control & PER_EVENT_MASK)) {
103 		regs->psw.mask &= ~PSW_MASK_PER;
104 		return;
105 	}
106 	regs->psw.mask |= PSW_MASK_PER;
107 	__ctl_store(old, 9, 11);
108 	if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
109 		__ctl_load(new, 9, 11);
110 }
111 
112 void user_enable_single_step(struct task_struct *task)
113 {
114 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
115 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
116 }
117 
118 void user_disable_single_step(struct task_struct *task)
119 {
120 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
121 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
122 }
123 
124 void user_enable_block_step(struct task_struct *task)
125 {
126 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
127 	set_tsk_thread_flag(task, TIF_BLOCK_STEP);
128 }
129 
130 /*
131  * Called by kernel/ptrace.c when detaching..
132  *
133  * Clear all debugging related fields.
134  */
135 void ptrace_disable(struct task_struct *task)
136 {
137 	memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
138 	memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
139 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
140 	clear_tsk_thread_flag(task, TIF_PER_TRAP);
141 	task->thread.per_flags = 0;
142 }
143 
144 #define __ADDR_MASK 7
145 
146 static inline unsigned long __peek_user_per(struct task_struct *child,
147 					    addr_t addr)
148 {
149 	if (addr == offsetof(struct per_struct_kernel, cr9))
150 		/* Control bits of the active per set. */
151 		return test_thread_flag(TIF_SINGLE_STEP) ?
152 			PER_EVENT_IFETCH : child->thread.per_user.control;
153 	else if (addr == offsetof(struct per_struct_kernel, cr10))
154 		/* Start address of the active per set. */
155 		return test_thread_flag(TIF_SINGLE_STEP) ?
156 			0 : child->thread.per_user.start;
157 	else if (addr == offsetof(struct per_struct_kernel, cr11))
158 		/* End address of the active per set. */
159 		return test_thread_flag(TIF_SINGLE_STEP) ?
160 			-1UL : child->thread.per_user.end;
161 	else if (addr == offsetof(struct per_struct_kernel, bits))
162 		/* Single-step bit. */
163 		return test_thread_flag(TIF_SINGLE_STEP) ?
164 			(1UL << (BITS_PER_LONG - 1)) : 0;
165 	else if (addr == offsetof(struct per_struct_kernel, starting_addr))
166 		/* Start address of the user specified per set. */
167 		return child->thread.per_user.start;
168 	else if (addr == offsetof(struct per_struct_kernel, ending_addr))
169 		/* End address of the user specified per set. */
170 		return child->thread.per_user.end;
171 	else if (addr == offsetof(struct per_struct_kernel, perc_atmid))
172 		/* PER code, ATMID and AI of the last PER trap */
173 		return (unsigned long)
174 			child->thread.per_event.cause << (BITS_PER_LONG - 16);
175 	else if (addr == offsetof(struct per_struct_kernel, address))
176 		/* Address of the last PER trap */
177 		return child->thread.per_event.address;
178 	else if (addr == offsetof(struct per_struct_kernel, access_id))
179 		/* Access id of the last PER trap */
180 		return (unsigned long)
181 			child->thread.per_event.paid << (BITS_PER_LONG - 8);
182 	return 0;
183 }
184 
185 /*
186  * Read the word at offset addr from the user area of a process. The
187  * trouble here is that the information is littered over different
188  * locations. The process registers are found on the kernel stack,
189  * the floating point stuff and the trace settings are stored in
190  * the task structure. In addition the different structures in
191  * struct user contain pad bytes that should be read as zeroes.
192  * Lovely...
193  */
194 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
195 {
196 	addr_t offset, tmp;
197 
198 	if (addr < offsetof(struct user, regs.acrs)) {
199 		/*
200 		 * psw and gprs are stored on the stack
201 		 */
202 		tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
203 		if (addr == offsetof(struct user, regs.psw.mask)) {
204 			/* Return a clean psw mask. */
205 			tmp &= PSW_MASK_USER | PSW_MASK_RI;
206 			tmp |= PSW_USER_BITS;
207 		}
208 
209 	} else if (addr < offsetof(struct user, regs.orig_gpr2)) {
210 		/*
211 		 * access registers are stored in the thread structure
212 		 */
213 		offset = addr - offsetof(struct user, regs.acrs);
214 		/*
215 		 * Very special case: old & broken 64 bit gdb reading
216 		 * from acrs[15]. Result is a 64 bit value. Read the
217 		 * 32 bit acrs[15] value and shift it by 32. Sick...
218 		 */
219 		if (addr == offsetof(struct user, regs.acrs[15]))
220 			tmp = ((unsigned long) child->thread.acrs[15]) << 32;
221 		else
222 			tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
223 
224 	} else if (addr == offsetof(struct user, regs.orig_gpr2)) {
225 		/*
226 		 * orig_gpr2 is stored on the kernel stack
227 		 */
228 		tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
229 
230 	} else if (addr < offsetof(struct user, regs.fp_regs)) {
231 		/*
232 		 * prevent reads of padding hole between
233 		 * orig_gpr2 and fp_regs on s390.
234 		 */
235 		tmp = 0;
236 
237 	} else if (addr == offsetof(struct user, regs.fp_regs.fpc)) {
238 		/*
239 		 * floating point control reg. is in the thread structure
240 		 */
241 		tmp = child->thread.fpu.fpc;
242 		tmp <<= BITS_PER_LONG - 32;
243 
244 	} else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
245 		/*
246 		 * floating point regs. are either in child->thread.fpu
247 		 * or the child->thread.fpu.vxrs array
248 		 */
249 		offset = addr - offsetof(struct user, regs.fp_regs.fprs);
250 		if (MACHINE_HAS_VX)
251 			tmp = *(addr_t *)
252 			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
253 		else
254 			tmp = *(addr_t *)
255 			       ((addr_t) child->thread.fpu.fprs + offset);
256 
257 	} else if (addr < offsetof(struct user, regs.per_info) + sizeof(per_struct)) {
258 		/*
259 		 * Handle access to the per_info structure.
260 		 */
261 		addr -= offsetof(struct user, regs.per_info);
262 		tmp = __peek_user_per(child, addr);
263 
264 	} else
265 		tmp = 0;
266 
267 	return tmp;
268 }
269 
270 static int
271 peek_user(struct task_struct *child, addr_t addr, addr_t data)
272 {
273 	addr_t tmp, mask;
274 
275 	/*
276 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
277 	 * an alignment of 4. Programmers from hell...
278 	 */
279 	mask = __ADDR_MASK;
280 	if (addr >= offsetof(struct user, regs.acrs) &&
281 	    addr < offsetof(struct user, regs.orig_gpr2))
282 		mask = 3;
283 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
284 		return -EIO;
285 
286 	tmp = __peek_user(child, addr);
287 	return put_user(tmp, (addr_t __user *) data);
288 }
289 
290 static inline void __poke_user_per(struct task_struct *child,
291 				   addr_t addr, addr_t data)
292 {
293 	/*
294 	 * There are only three fields in the per_info struct that the
295 	 * debugger user can write to.
296 	 * 1) cr9: the debugger wants to set a new PER event mask
297 	 * 2) starting_addr: the debugger wants to set a new starting
298 	 *    address to use with the PER event mask.
299 	 * 3) ending_addr: the debugger wants to set a new ending
300 	 *    address to use with the PER event mask.
301 	 * The user specified PER event mask and the start and end
302 	 * addresses are used only if single stepping is not in effect.
303 	 * Writes to any other field in per_info are ignored.
304 	 */
305 	if (addr == offsetof(struct per_struct_kernel, cr9))
306 		/* PER event mask of the user specified per set. */
307 		child->thread.per_user.control =
308 			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
309 	else if (addr == offsetof(struct per_struct_kernel, starting_addr))
310 		/* Starting address of the user specified per set. */
311 		child->thread.per_user.start = data;
312 	else if (addr == offsetof(struct per_struct_kernel, ending_addr))
313 		/* Ending address of the user specified per set. */
314 		child->thread.per_user.end = data;
315 }
316 
317 /*
318  * Write a word to the user area of a process at location addr. This
319  * operation does have an additional problem compared to peek_user.
320  * Stores to the program status word and on the floating point
321  * control register needs to get checked for validity.
322  */
323 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
324 {
325 	addr_t offset;
326 
327 
328 	if (addr < offsetof(struct user, regs.acrs)) {
329 		struct pt_regs *regs = task_pt_regs(child);
330 		/*
331 		 * psw and gprs are stored on the stack
332 		 */
333 		if (addr == offsetof(struct user, regs.psw.mask)) {
334 			unsigned long mask = PSW_MASK_USER;
335 
336 			mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
337 			if ((data ^ PSW_USER_BITS) & ~mask)
338 				/* Invalid psw mask. */
339 				return -EINVAL;
340 			if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
341 				/* Invalid address-space-control bits */
342 				return -EINVAL;
343 			if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
344 				/* Invalid addressing mode bits */
345 				return -EINVAL;
346 		}
347 
348 		if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
349 			addr == offsetof(struct user, regs.gprs[2])) {
350 			struct pt_regs *regs = task_pt_regs(child);
351 
352 			regs->int_code = 0x20000 | (data & 0xffff);
353 		}
354 		*(addr_t *)((addr_t) &regs->psw + addr) = data;
355 	} else if (addr < offsetof(struct user, regs.orig_gpr2)) {
356 		/*
357 		 * access registers are stored in the thread structure
358 		 */
359 		offset = addr - offsetof(struct user, regs.acrs);
360 		/*
361 		 * Very special case: old & broken 64 bit gdb writing
362 		 * to acrs[15] with a 64 bit value. Ignore the lower
363 		 * half of the value and write the upper 32 bit to
364 		 * acrs[15]. Sick...
365 		 */
366 		if (addr == offsetof(struct user, regs.acrs[15]))
367 			child->thread.acrs[15] = (unsigned int) (data >> 32);
368 		else
369 			*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
370 
371 	} else if (addr == offsetof(struct user, regs.orig_gpr2)) {
372 		/*
373 		 * orig_gpr2 is stored on the kernel stack
374 		 */
375 		task_pt_regs(child)->orig_gpr2 = data;
376 
377 	} else if (addr < offsetof(struct user, regs.fp_regs)) {
378 		/*
379 		 * prevent writes of padding hole between
380 		 * orig_gpr2 and fp_regs on s390.
381 		 */
382 		return 0;
383 
384 	} else if (addr == offsetof(struct user, regs.fp_regs.fpc)) {
385 		/*
386 		 * floating point control reg. is in the thread structure
387 		 */
388 		if ((unsigned int) data != 0 ||
389 		    test_fp_ctl(data >> (BITS_PER_LONG - 32)))
390 			return -EINVAL;
391 		child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
392 
393 	} else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
394 		/*
395 		 * floating point regs. are either in child->thread.fpu
396 		 * or the child->thread.fpu.vxrs array
397 		 */
398 		offset = addr - offsetof(struct user, regs.fp_regs.fprs);
399 		if (MACHINE_HAS_VX)
400 			*(addr_t *)((addr_t)
401 				child->thread.fpu.vxrs + 2*offset) = data;
402 		else
403 			*(addr_t *)((addr_t)
404 				child->thread.fpu.fprs + offset) = data;
405 
406 	} else if (addr < offsetof(struct user, regs.per_info) + sizeof(per_struct)) {
407 		/*
408 		 * Handle access to the per_info structure.
409 		 */
410 		addr -= offsetof(struct user, regs.per_info);
411 		__poke_user_per(child, addr, data);
412 
413 	}
414 
415 	return 0;
416 }
417 
418 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
419 {
420 	addr_t mask;
421 
422 	/*
423 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
424 	 * an alignment of 4. Programmers from hell indeed...
425 	 */
426 	mask = __ADDR_MASK;
427 	if (addr >= offsetof(struct user, regs.acrs) &&
428 	    addr < offsetof(struct user, regs.orig_gpr2))
429 		mask = 3;
430 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
431 		return -EIO;
432 
433 	return __poke_user(child, addr, data);
434 }
435 
436 long arch_ptrace(struct task_struct *child, long request,
437 		 unsigned long addr, unsigned long data)
438 {
439 	ptrace_area parea;
440 	int copied, ret;
441 
442 	switch (request) {
443 	case PTRACE_PEEKUSR:
444 		/* read the word at location addr in the USER area. */
445 		return peek_user(child, addr, data);
446 
447 	case PTRACE_POKEUSR:
448 		/* write the word at location addr in the USER area */
449 		return poke_user(child, addr, data);
450 
451 	case PTRACE_PEEKUSR_AREA:
452 	case PTRACE_POKEUSR_AREA:
453 		if (copy_from_user(&parea, (void __force __user *) addr,
454 							sizeof(parea)))
455 			return -EFAULT;
456 		addr = parea.kernel_addr;
457 		data = parea.process_addr;
458 		copied = 0;
459 		while (copied < parea.len) {
460 			if (request == PTRACE_PEEKUSR_AREA)
461 				ret = peek_user(child, addr, data);
462 			else {
463 				addr_t utmp;
464 				if (get_user(utmp,
465 					     (addr_t __force __user *) data))
466 					return -EFAULT;
467 				ret = poke_user(child, addr, utmp);
468 			}
469 			if (ret)
470 				return ret;
471 			addr += sizeof(unsigned long);
472 			data += sizeof(unsigned long);
473 			copied += sizeof(unsigned long);
474 		}
475 		return 0;
476 	case PTRACE_GET_LAST_BREAK:
477 		put_user(child->thread.last_break,
478 			 (unsigned long __user *) data);
479 		return 0;
480 	case PTRACE_ENABLE_TE:
481 		if (!MACHINE_HAS_TE)
482 			return -EIO;
483 		child->thread.per_flags &= ~PER_FLAG_NO_TE;
484 		return 0;
485 	case PTRACE_DISABLE_TE:
486 		if (!MACHINE_HAS_TE)
487 			return -EIO;
488 		child->thread.per_flags |= PER_FLAG_NO_TE;
489 		child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
490 		return 0;
491 	case PTRACE_TE_ABORT_RAND:
492 		if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
493 			return -EIO;
494 		switch (data) {
495 		case 0UL:
496 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
497 			break;
498 		case 1UL:
499 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
500 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
501 			break;
502 		case 2UL:
503 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
504 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
505 			break;
506 		default:
507 			return -EINVAL;
508 		}
509 		return 0;
510 	default:
511 		return ptrace_request(child, request, addr, data);
512 	}
513 }
514 
515 #ifdef CONFIG_COMPAT
516 /*
517  * Now the fun part starts... a 31 bit program running in the
518  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
519  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
520  * to handle, the difference to the 64 bit versions of the requests
521  * is that the access is done in multiples of 4 byte instead of
522  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
523  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
524  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
525  * is a 31 bit program too, the content of struct user can be
526  * emulated. A 31 bit program peeking into the struct user of
527  * a 64 bit program is a no-no.
528  */
529 
530 /*
531  * Same as peek_user_per but for a 31 bit program.
532  */
533 static inline __u32 __peek_user_per_compat(struct task_struct *child,
534 					   addr_t addr)
535 {
536 	if (addr == offsetof(struct compat_per_struct_kernel, cr9))
537 		/* Control bits of the active per set. */
538 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
539 			PER_EVENT_IFETCH : child->thread.per_user.control;
540 	else if (addr == offsetof(struct compat_per_struct_kernel, cr10))
541 		/* Start address of the active per set. */
542 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
543 			0 : child->thread.per_user.start;
544 	else if (addr == offsetof(struct compat_per_struct_kernel, cr11))
545 		/* End address of the active per set. */
546 		return test_thread_flag(TIF_SINGLE_STEP) ?
547 			PSW32_ADDR_INSN : child->thread.per_user.end;
548 	else if (addr == offsetof(struct compat_per_struct_kernel, bits))
549 		/* Single-step bit. */
550 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
551 			0x80000000 : 0;
552 	else if (addr == offsetof(struct compat_per_struct_kernel, starting_addr))
553 		/* Start address of the user specified per set. */
554 		return (__u32) child->thread.per_user.start;
555 	else if (addr == offsetof(struct compat_per_struct_kernel, ending_addr))
556 		/* End address of the user specified per set. */
557 		return (__u32) child->thread.per_user.end;
558 	else if (addr == offsetof(struct compat_per_struct_kernel, perc_atmid))
559 		/* PER code, ATMID and AI of the last PER trap */
560 		return (__u32) child->thread.per_event.cause << 16;
561 	else if (addr == offsetof(struct compat_per_struct_kernel, address))
562 		/* Address of the last PER trap */
563 		return (__u32) child->thread.per_event.address;
564 	else if (addr == offsetof(struct compat_per_struct_kernel, access_id))
565 		/* Access id of the last PER trap */
566 		return (__u32) child->thread.per_event.paid << 24;
567 	return 0;
568 }
569 
570 /*
571  * Same as peek_user but for a 31 bit program.
572  */
573 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
574 {
575 	addr_t offset;
576 	__u32 tmp;
577 
578 	if (addr < offsetof(struct compat_user, regs.acrs)) {
579 		struct pt_regs *regs = task_pt_regs(child);
580 		/*
581 		 * psw and gprs are stored on the stack
582 		 */
583 		if (addr == offsetof(struct compat_user, regs.psw.mask)) {
584 			/* Fake a 31 bit psw mask. */
585 			tmp = (__u32)(regs->psw.mask >> 32);
586 			tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
587 			tmp |= PSW32_USER_BITS;
588 		} else if (addr == offsetof(struct compat_user, regs.psw.addr)) {
589 			/* Fake a 31 bit psw address. */
590 			tmp = (__u32) regs->psw.addr |
591 				(__u32)(regs->psw.mask & PSW_MASK_BA);
592 		} else {
593 			/* gpr 0-15 */
594 			tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
595 		}
596 	} else if (addr < offsetof(struct compat_user, regs.orig_gpr2)) {
597 		/*
598 		 * access registers are stored in the thread structure
599 		 */
600 		offset = addr - offsetof(struct compat_user, regs.acrs);
601 		tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
602 
603 	} else if (addr == offsetof(struct compat_user, regs.orig_gpr2)) {
604 		/*
605 		 * orig_gpr2 is stored on the kernel stack
606 		 */
607 		tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
608 
609 	} else if (addr < offsetof(struct compat_user, regs.fp_regs)) {
610 		/*
611 		 * prevent reads of padding hole between
612 		 * orig_gpr2 and fp_regs on s390.
613 		 */
614 		tmp = 0;
615 
616 	} else if (addr == offsetof(struct compat_user, regs.fp_regs.fpc)) {
617 		/*
618 		 * floating point control reg. is in the thread structure
619 		 */
620 		tmp = child->thread.fpu.fpc;
621 
622 	} else if (addr < offsetof(struct compat_user, regs.fp_regs) + sizeof(s390_fp_regs)) {
623 		/*
624 		 * floating point regs. are either in child->thread.fpu
625 		 * or the child->thread.fpu.vxrs array
626 		 */
627 		offset = addr - offsetof(struct compat_user, regs.fp_regs.fprs);
628 		if (MACHINE_HAS_VX)
629 			tmp = *(__u32 *)
630 			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
631 		else
632 			tmp = *(__u32 *)
633 			       ((addr_t) child->thread.fpu.fprs + offset);
634 
635 	} else if (addr < offsetof(struct compat_user, regs.per_info) + sizeof(struct compat_per_struct_kernel)) {
636 		/*
637 		 * Handle access to the per_info structure.
638 		 */
639 		addr -= offsetof(struct compat_user, regs.per_info);
640 		tmp = __peek_user_per_compat(child, addr);
641 
642 	} else
643 		tmp = 0;
644 
645 	return tmp;
646 }
647 
648 static int peek_user_compat(struct task_struct *child,
649 			    addr_t addr, addr_t data)
650 {
651 	__u32 tmp;
652 
653 	if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
654 		return -EIO;
655 
656 	tmp = __peek_user_compat(child, addr);
657 	return put_user(tmp, (__u32 __user *) data);
658 }
659 
660 /*
661  * Same as poke_user_per but for a 31 bit program.
662  */
663 static inline void __poke_user_per_compat(struct task_struct *child,
664 					  addr_t addr, __u32 data)
665 {
666 	if (addr == offsetof(struct compat_per_struct_kernel, cr9))
667 		/* PER event mask of the user specified per set. */
668 		child->thread.per_user.control =
669 			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
670 	else if (addr == offsetof(struct compat_per_struct_kernel, starting_addr))
671 		/* Starting address of the user specified per set. */
672 		child->thread.per_user.start = data;
673 	else if (addr == offsetof(struct compat_per_struct_kernel, ending_addr))
674 		/* Ending address of the user specified per set. */
675 		child->thread.per_user.end = data;
676 }
677 
678 /*
679  * Same as poke_user but for a 31 bit program.
680  */
681 static int __poke_user_compat(struct task_struct *child,
682 			      addr_t addr, addr_t data)
683 {
684 	__u32 tmp = (__u32) data;
685 	addr_t offset;
686 
687 	if (addr < offsetof(struct compat_user, regs.acrs)) {
688 		struct pt_regs *regs = task_pt_regs(child);
689 		/*
690 		 * psw, gprs, acrs and orig_gpr2 are stored on the stack
691 		 */
692 		if (addr == offsetof(struct compat_user, regs.psw.mask)) {
693 			__u32 mask = PSW32_MASK_USER;
694 
695 			mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
696 			/* Build a 64 bit psw mask from 31 bit mask. */
697 			if ((tmp ^ PSW32_USER_BITS) & ~mask)
698 				/* Invalid psw mask. */
699 				return -EINVAL;
700 			if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
701 				/* Invalid address-space-control bits */
702 				return -EINVAL;
703 			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
704 				(regs->psw.mask & PSW_MASK_BA) |
705 				(__u64)(tmp & mask) << 32;
706 		} else if (addr == offsetof(struct compat_user, regs.psw.addr)) {
707 			/* Build a 64 bit psw address from 31 bit address. */
708 			regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
709 			/* Transfer 31 bit amode bit to psw mask. */
710 			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
711 				(__u64)(tmp & PSW32_ADDR_AMODE);
712 		} else {
713 			if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
714 				addr == offsetof(struct compat_user, regs.gprs[2])) {
715 				struct pt_regs *regs = task_pt_regs(child);
716 
717 				regs->int_code = 0x20000 | (data & 0xffff);
718 			}
719 			/* gpr 0-15 */
720 			*(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
721 		}
722 	} else if (addr < offsetof(struct compat_user, regs.orig_gpr2)) {
723 		/*
724 		 * access registers are stored in the thread structure
725 		 */
726 		offset = addr - offsetof(struct compat_user, regs.acrs);
727 		*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
728 
729 	} else if (addr == offsetof(struct compat_user, regs.orig_gpr2)) {
730 		/*
731 		 * orig_gpr2 is stored on the kernel stack
732 		 */
733 		*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
734 
735 	} else if (addr < offsetof(struct compat_user, regs.fp_regs)) {
736 		/*
737 		 * prevent writess of padding hole between
738 		 * orig_gpr2 and fp_regs on s390.
739 		 */
740 		return 0;
741 
742 	} else if (addr == offsetof(struct compat_user, regs.fp_regs.fpc)) {
743 		/*
744 		 * floating point control reg. is in the thread structure
745 		 */
746 		if (test_fp_ctl(tmp))
747 			return -EINVAL;
748 		child->thread.fpu.fpc = data;
749 
750 	} else if (addr < offsetof(struct compat_user, regs.fp_regs) + sizeof(s390_fp_regs)) {
751 		/*
752 		 * floating point regs. are either in child->thread.fpu
753 		 * or the child->thread.fpu.vxrs array
754 		 */
755 		offset = addr - offsetof(struct compat_user, regs.fp_regs.fprs);
756 		if (MACHINE_HAS_VX)
757 			*(__u32 *)((addr_t)
758 				child->thread.fpu.vxrs + 2*offset) = tmp;
759 		else
760 			*(__u32 *)((addr_t)
761 				child->thread.fpu.fprs + offset) = tmp;
762 
763 	} else if (addr < offsetof(struct compat_user, regs.per_info) + sizeof(struct compat_per_struct_kernel)) {
764 		/*
765 		 * Handle access to the per_info structure.
766 		 */
767 		addr -= offsetof(struct compat_user, regs.per_info);
768 		__poke_user_per_compat(child, addr, data);
769 	}
770 
771 	return 0;
772 }
773 
774 static int poke_user_compat(struct task_struct *child,
775 			    addr_t addr, addr_t data)
776 {
777 	if (!is_compat_task() || (addr & 3) ||
778 	    addr > sizeof(struct compat_user) - 3)
779 		return -EIO;
780 
781 	return __poke_user_compat(child, addr, data);
782 }
783 
784 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
785 			compat_ulong_t caddr, compat_ulong_t cdata)
786 {
787 	unsigned long addr = caddr;
788 	unsigned long data = cdata;
789 	compat_ptrace_area parea;
790 	int copied, ret;
791 
792 	switch (request) {
793 	case PTRACE_PEEKUSR:
794 		/* read the word at location addr in the USER area. */
795 		return peek_user_compat(child, addr, data);
796 
797 	case PTRACE_POKEUSR:
798 		/* write the word at location addr in the USER area */
799 		return poke_user_compat(child, addr, data);
800 
801 	case PTRACE_PEEKUSR_AREA:
802 	case PTRACE_POKEUSR_AREA:
803 		if (copy_from_user(&parea, (void __force __user *) addr,
804 							sizeof(parea)))
805 			return -EFAULT;
806 		addr = parea.kernel_addr;
807 		data = parea.process_addr;
808 		copied = 0;
809 		while (copied < parea.len) {
810 			if (request == PTRACE_PEEKUSR_AREA)
811 				ret = peek_user_compat(child, addr, data);
812 			else {
813 				__u32 utmp;
814 				if (get_user(utmp,
815 					     (__u32 __force __user *) data))
816 					return -EFAULT;
817 				ret = poke_user_compat(child, addr, utmp);
818 			}
819 			if (ret)
820 				return ret;
821 			addr += sizeof(unsigned int);
822 			data += sizeof(unsigned int);
823 			copied += sizeof(unsigned int);
824 		}
825 		return 0;
826 	case PTRACE_GET_LAST_BREAK:
827 		put_user(child->thread.last_break,
828 			 (unsigned int __user *) data);
829 		return 0;
830 	}
831 	return compat_ptrace_request(child, request, addr, data);
832 }
833 #endif
834 
835 /*
836  * user_regset definitions.
837  */
838 
839 static int s390_regs_get(struct task_struct *target,
840 			 const struct user_regset *regset,
841 			 struct membuf to)
842 {
843 	unsigned pos;
844 	if (target == current)
845 		save_access_regs(target->thread.acrs);
846 
847 	for (pos = 0; pos < sizeof(s390_regs); pos += sizeof(long))
848 		membuf_store(&to, __peek_user(target, pos));
849 	return 0;
850 }
851 
852 static int s390_regs_set(struct task_struct *target,
853 			 const struct user_regset *regset,
854 			 unsigned int pos, unsigned int count,
855 			 const void *kbuf, const void __user *ubuf)
856 {
857 	int rc = 0;
858 
859 	if (target == current)
860 		save_access_regs(target->thread.acrs);
861 
862 	if (kbuf) {
863 		const unsigned long *k = kbuf;
864 		while (count > 0 && !rc) {
865 			rc = __poke_user(target, pos, *k++);
866 			count -= sizeof(*k);
867 			pos += sizeof(*k);
868 		}
869 	} else {
870 		const unsigned long  __user *u = ubuf;
871 		while (count > 0 && !rc) {
872 			unsigned long word;
873 			rc = __get_user(word, u++);
874 			if (rc)
875 				break;
876 			rc = __poke_user(target, pos, word);
877 			count -= sizeof(*u);
878 			pos += sizeof(*u);
879 		}
880 	}
881 
882 	if (rc == 0 && target == current)
883 		restore_access_regs(target->thread.acrs);
884 
885 	return rc;
886 }
887 
888 static int s390_fpregs_get(struct task_struct *target,
889 			   const struct user_regset *regset,
890 			   struct membuf to)
891 {
892 	_s390_fp_regs fp_regs;
893 
894 	if (target == current)
895 		save_fpu_regs();
896 
897 	fp_regs.fpc = target->thread.fpu.fpc;
898 	fpregs_store(&fp_regs, &target->thread.fpu);
899 
900 	return membuf_write(&to, &fp_regs, sizeof(fp_regs));
901 }
902 
903 static int s390_fpregs_set(struct task_struct *target,
904 			   const struct user_regset *regset, unsigned int pos,
905 			   unsigned int count, const void *kbuf,
906 			   const void __user *ubuf)
907 {
908 	int rc = 0;
909 	freg_t fprs[__NUM_FPRS];
910 
911 	if (target == current)
912 		save_fpu_regs();
913 
914 	if (MACHINE_HAS_VX)
915 		convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
916 	else
917 		memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
918 
919 	/* If setting FPC, must validate it first. */
920 	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
921 		u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
922 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
923 					0, offsetof(s390_fp_regs, fprs));
924 		if (rc)
925 			return rc;
926 		if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
927 			return -EINVAL;
928 		target->thread.fpu.fpc = ufpc[0];
929 	}
930 
931 	if (rc == 0 && count > 0)
932 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
933 					fprs, offsetof(s390_fp_regs, fprs), -1);
934 	if (rc)
935 		return rc;
936 
937 	if (MACHINE_HAS_VX)
938 		convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
939 	else
940 		memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
941 
942 	return rc;
943 }
944 
945 static int s390_last_break_get(struct task_struct *target,
946 			       const struct user_regset *regset,
947 			       struct membuf to)
948 {
949 	return membuf_store(&to, target->thread.last_break);
950 }
951 
952 static int s390_last_break_set(struct task_struct *target,
953 			       const struct user_regset *regset,
954 			       unsigned int pos, unsigned int count,
955 			       const void *kbuf, const void __user *ubuf)
956 {
957 	return 0;
958 }
959 
960 static int s390_tdb_get(struct task_struct *target,
961 			const struct user_regset *regset,
962 			struct membuf to)
963 {
964 	struct pt_regs *regs = task_pt_regs(target);
965 	size_t size;
966 
967 	if (!(regs->int_code & 0x200))
968 		return -ENODATA;
969 	size = sizeof(target->thread.trap_tdb.data);
970 	return membuf_write(&to, target->thread.trap_tdb.data, size);
971 }
972 
973 static int s390_tdb_set(struct task_struct *target,
974 			const struct user_regset *regset,
975 			unsigned int pos, unsigned int count,
976 			const void *kbuf, const void __user *ubuf)
977 {
978 	return 0;
979 }
980 
981 static int s390_vxrs_low_get(struct task_struct *target,
982 			     const struct user_regset *regset,
983 			     struct membuf to)
984 {
985 	__u64 vxrs[__NUM_VXRS_LOW];
986 	int i;
987 
988 	if (!MACHINE_HAS_VX)
989 		return -ENODEV;
990 	if (target == current)
991 		save_fpu_regs();
992 	for (i = 0; i < __NUM_VXRS_LOW; i++)
993 		vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
994 	return membuf_write(&to, vxrs, sizeof(vxrs));
995 }
996 
997 static int s390_vxrs_low_set(struct task_struct *target,
998 			     const struct user_regset *regset,
999 			     unsigned int pos, unsigned int count,
1000 			     const void *kbuf, const void __user *ubuf)
1001 {
1002 	__u64 vxrs[__NUM_VXRS_LOW];
1003 	int i, rc;
1004 
1005 	if (!MACHINE_HAS_VX)
1006 		return -ENODEV;
1007 	if (target == current)
1008 		save_fpu_regs();
1009 
1010 	for (i = 0; i < __NUM_VXRS_LOW; i++)
1011 		vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1012 
1013 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1014 	if (rc == 0)
1015 		for (i = 0; i < __NUM_VXRS_LOW; i++)
1016 			*((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1017 
1018 	return rc;
1019 }
1020 
1021 static int s390_vxrs_high_get(struct task_struct *target,
1022 			      const struct user_regset *regset,
1023 			      struct membuf to)
1024 {
1025 	if (!MACHINE_HAS_VX)
1026 		return -ENODEV;
1027 	if (target == current)
1028 		save_fpu_regs();
1029 	return membuf_write(&to, target->thread.fpu.vxrs + __NUM_VXRS_LOW,
1030 			    __NUM_VXRS_HIGH * sizeof(__vector128));
1031 }
1032 
1033 static int s390_vxrs_high_set(struct task_struct *target,
1034 			      const struct user_regset *regset,
1035 			      unsigned int pos, unsigned int count,
1036 			      const void *kbuf, const void __user *ubuf)
1037 {
1038 	int rc;
1039 
1040 	if (!MACHINE_HAS_VX)
1041 		return -ENODEV;
1042 	if (target == current)
1043 		save_fpu_regs();
1044 
1045 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1046 				target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1047 	return rc;
1048 }
1049 
1050 static int s390_system_call_get(struct task_struct *target,
1051 				const struct user_regset *regset,
1052 				struct membuf to)
1053 {
1054 	return membuf_store(&to, target->thread.system_call);
1055 }
1056 
1057 static int s390_system_call_set(struct task_struct *target,
1058 				const struct user_regset *regset,
1059 				unsigned int pos, unsigned int count,
1060 				const void *kbuf, const void __user *ubuf)
1061 {
1062 	unsigned int *data = &target->thread.system_call;
1063 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1064 				  data, 0, sizeof(unsigned int));
1065 }
1066 
1067 static int s390_gs_cb_get(struct task_struct *target,
1068 			  const struct user_regset *regset,
1069 			  struct membuf to)
1070 {
1071 	struct gs_cb *data = target->thread.gs_cb;
1072 
1073 	if (!MACHINE_HAS_GS)
1074 		return -ENODEV;
1075 	if (!data)
1076 		return -ENODATA;
1077 	if (target == current)
1078 		save_gs_cb(data);
1079 	return membuf_write(&to, data, sizeof(struct gs_cb));
1080 }
1081 
1082 static int s390_gs_cb_set(struct task_struct *target,
1083 			  const struct user_regset *regset,
1084 			  unsigned int pos, unsigned int count,
1085 			  const void *kbuf, const void __user *ubuf)
1086 {
1087 	struct gs_cb gs_cb = { }, *data = NULL;
1088 	int rc;
1089 
1090 	if (!MACHINE_HAS_GS)
1091 		return -ENODEV;
1092 	if (!target->thread.gs_cb) {
1093 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1094 		if (!data)
1095 			return -ENOMEM;
1096 	}
1097 	if (!target->thread.gs_cb)
1098 		gs_cb.gsd = 25;
1099 	else if (target == current)
1100 		save_gs_cb(&gs_cb);
1101 	else
1102 		gs_cb = *target->thread.gs_cb;
1103 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1104 				&gs_cb, 0, sizeof(gs_cb));
1105 	if (rc) {
1106 		kfree(data);
1107 		return -EFAULT;
1108 	}
1109 	preempt_disable();
1110 	if (!target->thread.gs_cb)
1111 		target->thread.gs_cb = data;
1112 	*target->thread.gs_cb = gs_cb;
1113 	if (target == current) {
1114 		__ctl_set_bit(2, 4);
1115 		restore_gs_cb(target->thread.gs_cb);
1116 	}
1117 	preempt_enable();
1118 	return rc;
1119 }
1120 
1121 static int s390_gs_bc_get(struct task_struct *target,
1122 			  const struct user_regset *regset,
1123 			  struct membuf to)
1124 {
1125 	struct gs_cb *data = target->thread.gs_bc_cb;
1126 
1127 	if (!MACHINE_HAS_GS)
1128 		return -ENODEV;
1129 	if (!data)
1130 		return -ENODATA;
1131 	return membuf_write(&to, data, sizeof(struct gs_cb));
1132 }
1133 
1134 static int s390_gs_bc_set(struct task_struct *target,
1135 			  const struct user_regset *regset,
1136 			  unsigned int pos, unsigned int count,
1137 			  const void *kbuf, const void __user *ubuf)
1138 {
1139 	struct gs_cb *data = target->thread.gs_bc_cb;
1140 
1141 	if (!MACHINE_HAS_GS)
1142 		return -ENODEV;
1143 	if (!data) {
1144 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1145 		if (!data)
1146 			return -ENOMEM;
1147 		target->thread.gs_bc_cb = data;
1148 	}
1149 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1150 				  data, 0, sizeof(struct gs_cb));
1151 }
1152 
1153 static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1154 {
1155 	return (cb->rca & 0x1f) == 0 &&
1156 		(cb->roa & 0xfff) == 0 &&
1157 		(cb->rla & 0xfff) == 0xfff &&
1158 		cb->s == 1 &&
1159 		cb->k == 1 &&
1160 		cb->h == 0 &&
1161 		cb->reserved1 == 0 &&
1162 		cb->ps == 1 &&
1163 		cb->qs == 0 &&
1164 		cb->pc == 1 &&
1165 		cb->qc == 0 &&
1166 		cb->reserved2 == 0 &&
1167 		cb->reserved3 == 0 &&
1168 		cb->reserved4 == 0 &&
1169 		cb->reserved5 == 0 &&
1170 		cb->reserved6 == 0 &&
1171 		cb->reserved7 == 0 &&
1172 		cb->reserved8 == 0 &&
1173 		cb->rla >= cb->roa &&
1174 		cb->rca >= cb->roa &&
1175 		cb->rca <= cb->rla+1 &&
1176 		cb->m < 3;
1177 }
1178 
1179 static int s390_runtime_instr_get(struct task_struct *target,
1180 				const struct user_regset *regset,
1181 				struct membuf to)
1182 {
1183 	struct runtime_instr_cb *data = target->thread.ri_cb;
1184 
1185 	if (!test_facility(64))
1186 		return -ENODEV;
1187 	if (!data)
1188 		return -ENODATA;
1189 
1190 	return membuf_write(&to, data, sizeof(struct runtime_instr_cb));
1191 }
1192 
1193 static int s390_runtime_instr_set(struct task_struct *target,
1194 				  const struct user_regset *regset,
1195 				  unsigned int pos, unsigned int count,
1196 				  const void *kbuf, const void __user *ubuf)
1197 {
1198 	struct runtime_instr_cb ri_cb = { }, *data = NULL;
1199 	int rc;
1200 
1201 	if (!test_facility(64))
1202 		return -ENODEV;
1203 
1204 	if (!target->thread.ri_cb) {
1205 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1206 		if (!data)
1207 			return -ENOMEM;
1208 	}
1209 
1210 	if (target->thread.ri_cb) {
1211 		if (target == current)
1212 			store_runtime_instr_cb(&ri_cb);
1213 		else
1214 			ri_cb = *target->thread.ri_cb;
1215 	}
1216 
1217 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1218 				&ri_cb, 0, sizeof(struct runtime_instr_cb));
1219 	if (rc) {
1220 		kfree(data);
1221 		return -EFAULT;
1222 	}
1223 
1224 	if (!is_ri_cb_valid(&ri_cb)) {
1225 		kfree(data);
1226 		return -EINVAL;
1227 	}
1228 	/*
1229 	 * Override access key in any case, since user space should
1230 	 * not be able to set it, nor should it care about it.
1231 	 */
1232 	ri_cb.key = PAGE_DEFAULT_KEY >> 4;
1233 	preempt_disable();
1234 	if (!target->thread.ri_cb)
1235 		target->thread.ri_cb = data;
1236 	*target->thread.ri_cb = ri_cb;
1237 	if (target == current)
1238 		load_runtime_instr_cb(target->thread.ri_cb);
1239 	preempt_enable();
1240 
1241 	return 0;
1242 }
1243 
1244 static const struct user_regset s390_regsets[] = {
1245 	{
1246 		.core_note_type = NT_PRSTATUS,
1247 		.n = sizeof(s390_regs) / sizeof(long),
1248 		.size = sizeof(long),
1249 		.align = sizeof(long),
1250 		.regset_get = s390_regs_get,
1251 		.set = s390_regs_set,
1252 	},
1253 	{
1254 		.core_note_type = NT_PRFPREG,
1255 		.n = sizeof(s390_fp_regs) / sizeof(long),
1256 		.size = sizeof(long),
1257 		.align = sizeof(long),
1258 		.regset_get = s390_fpregs_get,
1259 		.set = s390_fpregs_set,
1260 	},
1261 	{
1262 		.core_note_type = NT_S390_SYSTEM_CALL,
1263 		.n = 1,
1264 		.size = sizeof(unsigned int),
1265 		.align = sizeof(unsigned int),
1266 		.regset_get = s390_system_call_get,
1267 		.set = s390_system_call_set,
1268 	},
1269 	{
1270 		.core_note_type = NT_S390_LAST_BREAK,
1271 		.n = 1,
1272 		.size = sizeof(long),
1273 		.align = sizeof(long),
1274 		.regset_get = s390_last_break_get,
1275 		.set = s390_last_break_set,
1276 	},
1277 	{
1278 		.core_note_type = NT_S390_TDB,
1279 		.n = 1,
1280 		.size = 256,
1281 		.align = 1,
1282 		.regset_get = s390_tdb_get,
1283 		.set = s390_tdb_set,
1284 	},
1285 	{
1286 		.core_note_type = NT_S390_VXRS_LOW,
1287 		.n = __NUM_VXRS_LOW,
1288 		.size = sizeof(__u64),
1289 		.align = sizeof(__u64),
1290 		.regset_get = s390_vxrs_low_get,
1291 		.set = s390_vxrs_low_set,
1292 	},
1293 	{
1294 		.core_note_type = NT_S390_VXRS_HIGH,
1295 		.n = __NUM_VXRS_HIGH,
1296 		.size = sizeof(__vector128),
1297 		.align = sizeof(__vector128),
1298 		.regset_get = s390_vxrs_high_get,
1299 		.set = s390_vxrs_high_set,
1300 	},
1301 	{
1302 		.core_note_type = NT_S390_GS_CB,
1303 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1304 		.size = sizeof(__u64),
1305 		.align = sizeof(__u64),
1306 		.regset_get = s390_gs_cb_get,
1307 		.set = s390_gs_cb_set,
1308 	},
1309 	{
1310 		.core_note_type = NT_S390_GS_BC,
1311 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1312 		.size = sizeof(__u64),
1313 		.align = sizeof(__u64),
1314 		.regset_get = s390_gs_bc_get,
1315 		.set = s390_gs_bc_set,
1316 	},
1317 	{
1318 		.core_note_type = NT_S390_RI_CB,
1319 		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1320 		.size = sizeof(__u64),
1321 		.align = sizeof(__u64),
1322 		.regset_get = s390_runtime_instr_get,
1323 		.set = s390_runtime_instr_set,
1324 	},
1325 };
1326 
1327 static const struct user_regset_view user_s390_view = {
1328 	.name = "s390x",
1329 	.e_machine = EM_S390,
1330 	.regsets = s390_regsets,
1331 	.n = ARRAY_SIZE(s390_regsets)
1332 };
1333 
1334 #ifdef CONFIG_COMPAT
1335 static int s390_compat_regs_get(struct task_struct *target,
1336 				const struct user_regset *regset,
1337 				struct membuf to)
1338 {
1339 	unsigned n;
1340 
1341 	if (target == current)
1342 		save_access_regs(target->thread.acrs);
1343 
1344 	for (n = 0; n < sizeof(s390_compat_regs); n += sizeof(compat_ulong_t))
1345 		membuf_store(&to, __peek_user_compat(target, n));
1346 	return 0;
1347 }
1348 
1349 static int s390_compat_regs_set(struct task_struct *target,
1350 				const struct user_regset *regset,
1351 				unsigned int pos, unsigned int count,
1352 				const void *kbuf, const void __user *ubuf)
1353 {
1354 	int rc = 0;
1355 
1356 	if (target == current)
1357 		save_access_regs(target->thread.acrs);
1358 
1359 	if (kbuf) {
1360 		const compat_ulong_t *k = kbuf;
1361 		while (count > 0 && !rc) {
1362 			rc = __poke_user_compat(target, pos, *k++);
1363 			count -= sizeof(*k);
1364 			pos += sizeof(*k);
1365 		}
1366 	} else {
1367 		const compat_ulong_t  __user *u = ubuf;
1368 		while (count > 0 && !rc) {
1369 			compat_ulong_t word;
1370 			rc = __get_user(word, u++);
1371 			if (rc)
1372 				break;
1373 			rc = __poke_user_compat(target, pos, word);
1374 			count -= sizeof(*u);
1375 			pos += sizeof(*u);
1376 		}
1377 	}
1378 
1379 	if (rc == 0 && target == current)
1380 		restore_access_regs(target->thread.acrs);
1381 
1382 	return rc;
1383 }
1384 
1385 static int s390_compat_regs_high_get(struct task_struct *target,
1386 				     const struct user_regset *regset,
1387 				     struct membuf to)
1388 {
1389 	compat_ulong_t *gprs_high;
1390 	int i;
1391 
1392 	gprs_high = (compat_ulong_t *)task_pt_regs(target)->gprs;
1393 	for (i = 0; i < NUM_GPRS; i++, gprs_high += 2)
1394 		membuf_store(&to, *gprs_high);
1395 	return 0;
1396 }
1397 
1398 static int s390_compat_regs_high_set(struct task_struct *target,
1399 				     const struct user_regset *regset,
1400 				     unsigned int pos, unsigned int count,
1401 				     const void *kbuf, const void __user *ubuf)
1402 {
1403 	compat_ulong_t *gprs_high;
1404 	int rc = 0;
1405 
1406 	gprs_high = (compat_ulong_t *)
1407 		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1408 	if (kbuf) {
1409 		const compat_ulong_t *k = kbuf;
1410 		while (count > 0) {
1411 			*gprs_high = *k++;
1412 			*gprs_high += 2;
1413 			count -= sizeof(*k);
1414 		}
1415 	} else {
1416 		const compat_ulong_t  __user *u = ubuf;
1417 		while (count > 0 && !rc) {
1418 			unsigned long word;
1419 			rc = __get_user(word, u++);
1420 			if (rc)
1421 				break;
1422 			*gprs_high = word;
1423 			*gprs_high += 2;
1424 			count -= sizeof(*u);
1425 		}
1426 	}
1427 
1428 	return rc;
1429 }
1430 
1431 static int s390_compat_last_break_get(struct task_struct *target,
1432 				      const struct user_regset *regset,
1433 				      struct membuf to)
1434 {
1435 	compat_ulong_t last_break = target->thread.last_break;
1436 
1437 	return membuf_store(&to, (unsigned long)last_break);
1438 }
1439 
1440 static int s390_compat_last_break_set(struct task_struct *target,
1441 				      const struct user_regset *regset,
1442 				      unsigned int pos, unsigned int count,
1443 				      const void *kbuf, const void __user *ubuf)
1444 {
1445 	return 0;
1446 }
1447 
1448 static const struct user_regset s390_compat_regsets[] = {
1449 	{
1450 		.core_note_type = NT_PRSTATUS,
1451 		.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1452 		.size = sizeof(compat_long_t),
1453 		.align = sizeof(compat_long_t),
1454 		.regset_get = s390_compat_regs_get,
1455 		.set = s390_compat_regs_set,
1456 	},
1457 	{
1458 		.core_note_type = NT_PRFPREG,
1459 		.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1460 		.size = sizeof(compat_long_t),
1461 		.align = sizeof(compat_long_t),
1462 		.regset_get = s390_fpregs_get,
1463 		.set = s390_fpregs_set,
1464 	},
1465 	{
1466 		.core_note_type = NT_S390_SYSTEM_CALL,
1467 		.n = 1,
1468 		.size = sizeof(compat_uint_t),
1469 		.align = sizeof(compat_uint_t),
1470 		.regset_get = s390_system_call_get,
1471 		.set = s390_system_call_set,
1472 	},
1473 	{
1474 		.core_note_type = NT_S390_LAST_BREAK,
1475 		.n = 1,
1476 		.size = sizeof(long),
1477 		.align = sizeof(long),
1478 		.regset_get = s390_compat_last_break_get,
1479 		.set = s390_compat_last_break_set,
1480 	},
1481 	{
1482 		.core_note_type = NT_S390_TDB,
1483 		.n = 1,
1484 		.size = 256,
1485 		.align = 1,
1486 		.regset_get = s390_tdb_get,
1487 		.set = s390_tdb_set,
1488 	},
1489 	{
1490 		.core_note_type = NT_S390_VXRS_LOW,
1491 		.n = __NUM_VXRS_LOW,
1492 		.size = sizeof(__u64),
1493 		.align = sizeof(__u64),
1494 		.regset_get = s390_vxrs_low_get,
1495 		.set = s390_vxrs_low_set,
1496 	},
1497 	{
1498 		.core_note_type = NT_S390_VXRS_HIGH,
1499 		.n = __NUM_VXRS_HIGH,
1500 		.size = sizeof(__vector128),
1501 		.align = sizeof(__vector128),
1502 		.regset_get = s390_vxrs_high_get,
1503 		.set = s390_vxrs_high_set,
1504 	},
1505 	{
1506 		.core_note_type = NT_S390_HIGH_GPRS,
1507 		.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1508 		.size = sizeof(compat_long_t),
1509 		.align = sizeof(compat_long_t),
1510 		.regset_get = s390_compat_regs_high_get,
1511 		.set = s390_compat_regs_high_set,
1512 	},
1513 	{
1514 		.core_note_type = NT_S390_GS_CB,
1515 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1516 		.size = sizeof(__u64),
1517 		.align = sizeof(__u64),
1518 		.regset_get = s390_gs_cb_get,
1519 		.set = s390_gs_cb_set,
1520 	},
1521 	{
1522 		.core_note_type = NT_S390_GS_BC,
1523 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1524 		.size = sizeof(__u64),
1525 		.align = sizeof(__u64),
1526 		.regset_get = s390_gs_bc_get,
1527 		.set = s390_gs_bc_set,
1528 	},
1529 	{
1530 		.core_note_type = NT_S390_RI_CB,
1531 		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1532 		.size = sizeof(__u64),
1533 		.align = sizeof(__u64),
1534 		.regset_get = s390_runtime_instr_get,
1535 		.set = s390_runtime_instr_set,
1536 	},
1537 };
1538 
1539 static const struct user_regset_view user_s390_compat_view = {
1540 	.name = "s390",
1541 	.e_machine = EM_S390,
1542 	.regsets = s390_compat_regsets,
1543 	.n = ARRAY_SIZE(s390_compat_regsets)
1544 };
1545 #endif
1546 
1547 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1548 {
1549 #ifdef CONFIG_COMPAT
1550 	if (test_tsk_thread_flag(task, TIF_31BIT))
1551 		return &user_s390_compat_view;
1552 #endif
1553 	return &user_s390_view;
1554 }
1555 
1556 static const char *gpr_names[NUM_GPRS] = {
1557 	"r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1558 	"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1559 };
1560 
1561 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1562 {
1563 	if (offset >= NUM_GPRS)
1564 		return 0;
1565 	return regs->gprs[offset];
1566 }
1567 
1568 int regs_query_register_offset(const char *name)
1569 {
1570 	unsigned long offset;
1571 
1572 	if (!name || *name != 'r')
1573 		return -EINVAL;
1574 	if (kstrtoul(name + 1, 10, &offset))
1575 		return -EINVAL;
1576 	if (offset >= NUM_GPRS)
1577 		return -EINVAL;
1578 	return offset;
1579 }
1580 
1581 const char *regs_query_register_name(unsigned int offset)
1582 {
1583 	if (offset >= NUM_GPRS)
1584 		return NULL;
1585 	return gpr_names[offset];
1586 }
1587 
1588 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1589 {
1590 	unsigned long ksp = kernel_stack_pointer(regs);
1591 
1592 	return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1593 }
1594 
1595 /**
1596  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1597  * @regs:pt_regs which contains kernel stack pointer.
1598  * @n:stack entry number.
1599  *
1600  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1601  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1602  * this returns 0.
1603  */
1604 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1605 {
1606 	unsigned long addr;
1607 
1608 	addr = kernel_stack_pointer(regs) + n * sizeof(long);
1609 	if (!regs_within_kernel_stack(regs, addr))
1610 		return 0;
1611 	return *(unsigned long *)addr;
1612 }
1613