xref: /linux/arch/s390/kernel/ptrace.c (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
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/cpufeature.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 <trace/syscall.h>
26 #include <asm/guarded_storage.h>
27 #include <asm/access-regs.h>
28 #include <asm/page.h>
29 #include <linux/uaccess.h>
30 #include <asm/unistd.h>
31 #include <asm/runtime_instr.h>
32 #include <asm/facility.h>
33 #include <asm/machine.h>
34 #include <asm/ptrace.h>
35 #include <asm/rwonce.h>
36 #include <asm/fpu.h>
37 
38 #include "entry.h"
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 	union ctlreg0 cr0_old, cr0_new;
45 	union ctlreg2 cr2_old, cr2_new;
46 	int cr0_changed, cr2_changed;
47 	union {
48 		struct ctlreg regs[3];
49 		struct {
50 			struct ctlreg control;
51 			struct ctlreg start;
52 			struct ctlreg end;
53 		};
54 	} old, new;
55 
56 	local_ctl_store(0, &cr0_old.reg);
57 	local_ctl_store(2, &cr2_old.reg);
58 	cr0_new = cr0_old;
59 	cr2_new = cr2_old;
60 	/* Take care of the enable/disable of transactional execution. */
61 	if (machine_has_tx()) {
62 		/* Set or clear transaction execution TXC bit 8. */
63 		cr0_new.tcx = 1;
64 		if (task->thread.per_flags & PER_FLAG_NO_TE)
65 			cr0_new.tcx = 0;
66 		/* Set or clear transaction execution TDC bits 62 and 63. */
67 		cr2_new.tdc = 0;
68 		if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
69 			if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
70 				cr2_new.tdc = 1;
71 			else
72 				cr2_new.tdc = 2;
73 		}
74 	}
75 	/* Take care of enable/disable of guarded storage. */
76 	if (cpu_has_gs()) {
77 		cr2_new.gse = 0;
78 		if (task->thread.gs_cb)
79 			cr2_new.gse = 1;
80 	}
81 	/* Load control register 0/2 iff changed */
82 	cr0_changed = cr0_new.val != cr0_old.val;
83 	cr2_changed = cr2_new.val != cr2_old.val;
84 	if (cr0_changed)
85 		local_ctl_load(0, &cr0_new.reg);
86 	if (cr2_changed)
87 		local_ctl_load(2, &cr2_new.reg);
88 	/* Copy user specified PER registers */
89 	new.control.val = thread->per_user.control;
90 	new.start.val = thread->per_user.start;
91 	new.end.val = thread->per_user.end;
92 
93 	/* merge TIF_SINGLE_STEP into user specified PER registers. */
94 	if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
95 	    test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
96 		if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
97 			new.control.val |= PER_EVENT_BRANCH;
98 		else
99 			new.control.val |= PER_EVENT_IFETCH;
100 		new.control.val |= PER_CONTROL_SUSPENSION;
101 		new.control.val |= PER_EVENT_TRANSACTION_END;
102 		if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
103 			new.control.val |= PER_EVENT_IFETCH;
104 		new.start.val = 0;
105 		new.end.val = -1UL;
106 	}
107 
108 	/* Take care of the PER enablement bit in the PSW. */
109 	if (!(new.control.val & PER_EVENT_MASK)) {
110 		regs->psw.mask &= ~PSW_MASK_PER;
111 		return;
112 	}
113 	regs->psw.mask |= PSW_MASK_PER;
114 	__local_ctl_store(9, 11, old.regs);
115 	if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
116 		__local_ctl_load(9, 11, new.regs);
117 }
118 
119 void user_enable_single_step(struct task_struct *task)
120 {
121 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
122 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
123 }
124 
125 void user_disable_single_step(struct task_struct *task)
126 {
127 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
128 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
129 }
130 
131 void user_enable_block_step(struct task_struct *task)
132 {
133 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
134 	set_tsk_thread_flag(task, TIF_BLOCK_STEP);
135 }
136 
137 /*
138  * Called by kernel/ptrace.c when detaching..
139  *
140  * Clear all debugging related fields.
141  */
142 void ptrace_disable(struct task_struct *task)
143 {
144 	memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
145 	memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
146 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
147 	clear_tsk_thread_flag(task, TIF_PER_TRAP);
148 	task->thread.per_flags = 0;
149 }
150 
151 #define __ADDR_MASK 7
152 
153 static inline unsigned long __peek_user_per(struct task_struct *child,
154 					    addr_t addr)
155 {
156 	if (addr == offsetof(struct per_struct_kernel, cr9))
157 		/* Control bits of the active per set. */
158 		return test_thread_flag(TIF_SINGLE_STEP) ?
159 			PER_EVENT_IFETCH : child->thread.per_user.control;
160 	else if (addr == offsetof(struct per_struct_kernel, cr10))
161 		/* Start address of the active per set. */
162 		return test_thread_flag(TIF_SINGLE_STEP) ?
163 			0 : child->thread.per_user.start;
164 	else if (addr == offsetof(struct per_struct_kernel, cr11))
165 		/* End address of the active per set. */
166 		return test_thread_flag(TIF_SINGLE_STEP) ?
167 			-1UL : child->thread.per_user.end;
168 	else if (addr == offsetof(struct per_struct_kernel, bits))
169 		/* Single-step bit. */
170 		return test_thread_flag(TIF_SINGLE_STEP) ?
171 			(1UL << (BITS_PER_LONG - 1)) : 0;
172 	else if (addr == offsetof(struct per_struct_kernel, starting_addr))
173 		/* Start address of the user specified per set. */
174 		return child->thread.per_user.start;
175 	else if (addr == offsetof(struct per_struct_kernel, ending_addr))
176 		/* End address of the user specified per set. */
177 		return child->thread.per_user.end;
178 	else if (addr == offsetof(struct per_struct_kernel, perc_atmid))
179 		/* PER code, ATMID and AI of the last PER trap */
180 		return (unsigned long)
181 			child->thread.per_event.cause << (BITS_PER_LONG - 16);
182 	else if (addr == offsetof(struct per_struct_kernel, address))
183 		/* Address of the last PER trap */
184 		return child->thread.per_event.address;
185 	else if (addr == offsetof(struct per_struct_kernel, access_id))
186 		/* Access id of the last PER trap */
187 		return (unsigned long)
188 			child->thread.per_event.paid << (BITS_PER_LONG - 8);
189 	return 0;
190 }
191 
192 /*
193  * Read the word at offset addr from the user area of a process. The
194  * trouble here is that the information is littered over different
195  * locations. The process registers are found on the kernel stack,
196  * the floating point stuff and the trace settings are stored in
197  * the task structure. In addition the different structures in
198  * struct user contain pad bytes that should be read as zeroes.
199  * Lovely...
200  */
201 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
202 {
203 	addr_t offset, tmp;
204 
205 	if (addr < offsetof(struct user, regs.acrs)) {
206 		/*
207 		 * psw and gprs are stored on the stack
208 		 */
209 		tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
210 		if (addr == offsetof(struct user, regs.psw.mask)) {
211 			/* Return a clean psw mask. */
212 			tmp &= PSW_MASK_USER | PSW_MASK_RI;
213 			tmp |= PSW_USER_BITS;
214 		}
215 
216 	} else if (addr < offsetof(struct user, regs.orig_gpr2)) {
217 		/*
218 		 * access registers are stored in the thread structure
219 		 */
220 		offset = addr - offsetof(struct user, regs.acrs);
221 		/*
222 		 * Very special case: old & broken 64 bit gdb reading
223 		 * from acrs[15]. Result is a 64 bit value. Read the
224 		 * 32 bit acrs[15] value and shift it by 32. Sick...
225 		 */
226 		if (addr == offsetof(struct user, regs.acrs[15]))
227 			tmp = ((unsigned long) child->thread.acrs[15]) << 32;
228 		else
229 			tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
230 
231 	} else if (addr == offsetof(struct user, regs.orig_gpr2)) {
232 		/*
233 		 * orig_gpr2 is stored on the kernel stack
234 		 */
235 		tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
236 
237 	} else if (addr < offsetof(struct user, regs.fp_regs)) {
238 		/*
239 		 * prevent reads of padding hole between
240 		 * orig_gpr2 and fp_regs on s390.
241 		 */
242 		tmp = 0;
243 
244 	} else if (addr == offsetof(struct user, regs.fp_regs.fpc)) {
245 		/*
246 		 * floating point control reg. is in the thread structure
247 		 */
248 		tmp = child->thread.ufpu.fpc;
249 		tmp <<= BITS_PER_LONG - 32;
250 
251 	} else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
252 		/*
253 		 * floating point regs. are in the child->thread.ufpu.vxrs array
254 		 */
255 		offset = addr - offsetof(struct user, regs.fp_regs.fprs);
256 		tmp = *(addr_t *)((addr_t)child->thread.ufpu.vxrs + 2 * offset);
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 			return -EINVAL;
390 		child->thread.ufpu.fpc = data >> (BITS_PER_LONG - 32);
391 
392 	} else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
393 		/*
394 		 * floating point regs. are in the child->thread.ufpu.vxrs array
395 		 */
396 		offset = addr - offsetof(struct user, regs.fp_regs.fprs);
397 		*(addr_t *)((addr_t)child->thread.ufpu.vxrs + 2 * offset) = data;
398 	} else if (addr < offsetof(struct user, regs.per_info) + sizeof(per_struct)) {
399 		/*
400 		 * Handle access to the per_info structure.
401 		 */
402 		addr -= offsetof(struct user, regs.per_info);
403 		__poke_user_per(child, addr, data);
404 
405 	}
406 
407 	return 0;
408 }
409 
410 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
411 {
412 	addr_t mask;
413 
414 	/*
415 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
416 	 * an alignment of 4. Programmers from hell indeed...
417 	 */
418 	mask = __ADDR_MASK;
419 	if (addr >= offsetof(struct user, regs.acrs) &&
420 	    addr < offsetof(struct user, regs.orig_gpr2))
421 		mask = 3;
422 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
423 		return -EIO;
424 
425 	return __poke_user(child, addr, data);
426 }
427 
428 long arch_ptrace(struct task_struct *child, long request,
429 		 unsigned long addr, unsigned long data)
430 {
431 	ptrace_area parea;
432 	int copied, ret;
433 
434 	switch (request) {
435 	case PTRACE_PEEKUSR:
436 		/* read the word at location addr in the USER area. */
437 		return peek_user(child, addr, data);
438 
439 	case PTRACE_POKEUSR:
440 		/* write the word at location addr in the USER area */
441 		return poke_user(child, addr, data);
442 
443 	case PTRACE_PEEKUSR_AREA:
444 	case PTRACE_POKEUSR_AREA:
445 		if (copy_from_user(&parea, (void __force __user *) addr,
446 							sizeof(parea)))
447 			return -EFAULT;
448 		addr = parea.kernel_addr;
449 		data = parea.process_addr;
450 		copied = 0;
451 		while (copied < parea.len) {
452 			if (request == PTRACE_PEEKUSR_AREA)
453 				ret = peek_user(child, addr, data);
454 			else {
455 				addr_t utmp;
456 				if (get_user(utmp,
457 					     (addr_t __force __user *) data))
458 					return -EFAULT;
459 				ret = poke_user(child, addr, utmp);
460 			}
461 			if (ret)
462 				return ret;
463 			addr += sizeof(unsigned long);
464 			data += sizeof(unsigned long);
465 			copied += sizeof(unsigned long);
466 		}
467 		return 0;
468 	case PTRACE_GET_LAST_BREAK:
469 		return put_user(child->thread.last_break, (unsigned long __user *)data);
470 	case PTRACE_ENABLE_TE:
471 		if (!machine_has_tx())
472 			return -EIO;
473 		child->thread.per_flags &= ~PER_FLAG_NO_TE;
474 		return 0;
475 	case PTRACE_DISABLE_TE:
476 		if (!machine_has_tx())
477 			return -EIO;
478 		child->thread.per_flags |= PER_FLAG_NO_TE;
479 		child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
480 		return 0;
481 	case PTRACE_TE_ABORT_RAND:
482 		if (!machine_has_tx() || (child->thread.per_flags & PER_FLAG_NO_TE))
483 			return -EIO;
484 		switch (data) {
485 		case 0UL:
486 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
487 			break;
488 		case 1UL:
489 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
490 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
491 			break;
492 		case 2UL:
493 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
494 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
495 			break;
496 		default:
497 			return -EINVAL;
498 		}
499 		return 0;
500 	default:
501 		return ptrace_request(child, request, addr, data);
502 	}
503 }
504 
505 /*
506  * user_regset definitions.
507  */
508 
509 static int s390_regs_get(struct task_struct *target,
510 			 const struct user_regset *regset,
511 			 struct membuf to)
512 {
513 	unsigned pos;
514 	if (target == current)
515 		save_access_regs(target->thread.acrs);
516 
517 	for (pos = 0; pos < sizeof(s390_regs); pos += sizeof(long))
518 		membuf_store(&to, __peek_user(target, pos));
519 	return 0;
520 }
521 
522 static int s390_regs_set(struct task_struct *target,
523 			 const struct user_regset *regset,
524 			 unsigned int pos, unsigned int count,
525 			 const void *kbuf, const void __user *ubuf)
526 {
527 	int rc = 0;
528 
529 	if (target == current)
530 		save_access_regs(target->thread.acrs);
531 
532 	if (kbuf) {
533 		const unsigned long *k = kbuf;
534 		while (count > 0 && !rc) {
535 			rc = __poke_user(target, pos, *k++);
536 			count -= sizeof(*k);
537 			pos += sizeof(*k);
538 		}
539 	} else {
540 		const unsigned long  __user *u = ubuf;
541 		while (count > 0 && !rc) {
542 			unsigned long word;
543 			rc = __get_user(word, u++);
544 			if (rc)
545 				break;
546 			rc = __poke_user(target, pos, word);
547 			count -= sizeof(*u);
548 			pos += sizeof(*u);
549 		}
550 	}
551 
552 	if (rc == 0 && target == current)
553 		restore_access_regs(target->thread.acrs);
554 
555 	return rc;
556 }
557 
558 static int s390_fpregs_get(struct task_struct *target,
559 			   const struct user_regset *regset,
560 			   struct membuf to)
561 {
562 	_s390_fp_regs fp_regs;
563 
564 	if (target == current)
565 		save_user_fpu_regs();
566 
567 	fp_regs.fpc = target->thread.ufpu.fpc;
568 	fpregs_store(&fp_regs, &target->thread.ufpu);
569 
570 	return membuf_write(&to, &fp_regs, sizeof(fp_regs));
571 }
572 
573 static int s390_fpregs_set(struct task_struct *target,
574 			   const struct user_regset *regset, unsigned int pos,
575 			   unsigned int count, const void *kbuf,
576 			   const void __user *ubuf)
577 {
578 	int rc = 0;
579 	freg_t fprs[__NUM_FPRS];
580 
581 	if (target == current)
582 		save_user_fpu_regs();
583 	convert_vx_to_fp(fprs, target->thread.ufpu.vxrs);
584 	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
585 		u32 ufpc[2] = { target->thread.ufpu.fpc, 0 };
586 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
587 					0, offsetof(s390_fp_regs, fprs));
588 		if (rc)
589 			return rc;
590 		if (ufpc[1] != 0)
591 			return -EINVAL;
592 		target->thread.ufpu.fpc = ufpc[0];
593 	}
594 
595 	if (rc == 0 && count > 0)
596 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
597 					fprs, offsetof(s390_fp_regs, fprs), -1);
598 	if (rc)
599 		return rc;
600 	convert_fp_to_vx(target->thread.ufpu.vxrs, fprs);
601 	return rc;
602 }
603 
604 static int s390_last_break_get(struct task_struct *target,
605 			       const struct user_regset *regset,
606 			       struct membuf to)
607 {
608 	return membuf_store(&to, target->thread.last_break);
609 }
610 
611 static int s390_last_break_set(struct task_struct *target,
612 			       const struct user_regset *regset,
613 			       unsigned int pos, unsigned int count,
614 			       const void *kbuf, const void __user *ubuf)
615 {
616 	return 0;
617 }
618 
619 static int s390_tdb_get(struct task_struct *target,
620 			const struct user_regset *regset,
621 			struct membuf to)
622 {
623 	struct pt_regs *regs = task_pt_regs(target);
624 	size_t size;
625 
626 	if (!(regs->int_code & 0x200))
627 		return -ENODATA;
628 	size = sizeof(target->thread.trap_tdb.data);
629 	return membuf_write(&to, target->thread.trap_tdb.data, size);
630 }
631 
632 static int s390_tdb_set(struct task_struct *target,
633 			const struct user_regset *regset,
634 			unsigned int pos, unsigned int count,
635 			const void *kbuf, const void __user *ubuf)
636 {
637 	return 0;
638 }
639 
640 static int s390_vxrs_low_get(struct task_struct *target,
641 			     const struct user_regset *regset,
642 			     struct membuf to)
643 {
644 	__u64 vxrs[__NUM_VXRS_LOW];
645 	int i;
646 
647 	if (!cpu_has_vx())
648 		return -ENODEV;
649 	if (target == current)
650 		save_user_fpu_regs();
651 	for (i = 0; i < __NUM_VXRS_LOW; i++)
652 		vxrs[i] = target->thread.ufpu.vxrs[i].low;
653 	return membuf_write(&to, vxrs, sizeof(vxrs));
654 }
655 
656 static int s390_vxrs_low_set(struct task_struct *target,
657 			     const struct user_regset *regset,
658 			     unsigned int pos, unsigned int count,
659 			     const void *kbuf, const void __user *ubuf)
660 {
661 	__u64 vxrs[__NUM_VXRS_LOW];
662 	int i, rc;
663 
664 	if (!cpu_has_vx())
665 		return -ENODEV;
666 	if (target == current)
667 		save_user_fpu_regs();
668 
669 	for (i = 0; i < __NUM_VXRS_LOW; i++)
670 		vxrs[i] = target->thread.ufpu.vxrs[i].low;
671 
672 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
673 	if (rc == 0)
674 		for (i = 0; i < __NUM_VXRS_LOW; i++)
675 			target->thread.ufpu.vxrs[i].low = vxrs[i];
676 
677 	return rc;
678 }
679 
680 static int s390_vxrs_high_get(struct task_struct *target,
681 			      const struct user_regset *regset,
682 			      struct membuf to)
683 {
684 	if (!cpu_has_vx())
685 		return -ENODEV;
686 	if (target == current)
687 		save_user_fpu_regs();
688 	return membuf_write(&to, target->thread.ufpu.vxrs + __NUM_VXRS_LOW,
689 			    __NUM_VXRS_HIGH * sizeof(__vector128));
690 }
691 
692 static int s390_vxrs_high_set(struct task_struct *target,
693 			      const struct user_regset *regset,
694 			      unsigned int pos, unsigned int count,
695 			      const void *kbuf, const void __user *ubuf)
696 {
697 	int rc;
698 
699 	if (!cpu_has_vx())
700 		return -ENODEV;
701 	if (target == current)
702 		save_user_fpu_regs();
703 
704 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
705 				target->thread.ufpu.vxrs + __NUM_VXRS_LOW, 0, -1);
706 	return rc;
707 }
708 
709 static int s390_system_call_get(struct task_struct *target,
710 				const struct user_regset *regset,
711 				struct membuf to)
712 {
713 	return membuf_store(&to, target->thread.system_call);
714 }
715 
716 static int s390_system_call_set(struct task_struct *target,
717 				const struct user_regset *regset,
718 				unsigned int pos, unsigned int count,
719 				const void *kbuf, const void __user *ubuf)
720 {
721 	unsigned int *data = &target->thread.system_call;
722 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
723 				  data, 0, sizeof(unsigned int));
724 }
725 
726 static int s390_gs_cb_get(struct task_struct *target,
727 			  const struct user_regset *regset,
728 			  struct membuf to)
729 {
730 	struct gs_cb *data = target->thread.gs_cb;
731 
732 	if (!cpu_has_gs())
733 		return -ENODEV;
734 	if (!data)
735 		return -ENODATA;
736 	if (target == current)
737 		save_gs_cb(data);
738 	return membuf_write(&to, data, sizeof(struct gs_cb));
739 }
740 
741 static int s390_gs_cb_set(struct task_struct *target,
742 			  const struct user_regset *regset,
743 			  unsigned int pos, unsigned int count,
744 			  const void *kbuf, const void __user *ubuf)
745 {
746 	struct gs_cb gs_cb = { }, *data = NULL;
747 	int rc;
748 
749 	if (!cpu_has_gs())
750 		return -ENODEV;
751 	if (!target->thread.gs_cb) {
752 		data = kzalloc(sizeof(*data), GFP_KERNEL);
753 		if (!data)
754 			return -ENOMEM;
755 	}
756 	if (!target->thread.gs_cb)
757 		gs_cb.gsd = 25;
758 	else if (target == current)
759 		save_gs_cb(&gs_cb);
760 	else
761 		gs_cb = *target->thread.gs_cb;
762 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
763 				&gs_cb, 0, sizeof(gs_cb));
764 	if (rc) {
765 		kfree(data);
766 		return -EFAULT;
767 	}
768 	preempt_disable();
769 	if (!target->thread.gs_cb)
770 		target->thread.gs_cb = data;
771 	*target->thread.gs_cb = gs_cb;
772 	if (target == current) {
773 		local_ctl_set_bit(2, CR2_GUARDED_STORAGE_BIT);
774 		restore_gs_cb(target->thread.gs_cb);
775 	}
776 	preempt_enable();
777 	return rc;
778 }
779 
780 static int s390_gs_bc_get(struct task_struct *target,
781 			  const struct user_regset *regset,
782 			  struct membuf to)
783 {
784 	struct gs_cb *data = target->thread.gs_bc_cb;
785 
786 	if (!cpu_has_gs())
787 		return -ENODEV;
788 	if (!data)
789 		return -ENODATA;
790 	return membuf_write(&to, data, sizeof(struct gs_cb));
791 }
792 
793 static int s390_gs_bc_set(struct task_struct *target,
794 			  const struct user_regset *regset,
795 			  unsigned int pos, unsigned int count,
796 			  const void *kbuf, const void __user *ubuf)
797 {
798 	struct gs_cb *data = target->thread.gs_bc_cb;
799 
800 	if (!cpu_has_gs())
801 		return -ENODEV;
802 	if (!data) {
803 		data = kzalloc(sizeof(*data), GFP_KERNEL);
804 		if (!data)
805 			return -ENOMEM;
806 		target->thread.gs_bc_cb = data;
807 	}
808 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
809 				  data, 0, sizeof(struct gs_cb));
810 }
811 
812 static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
813 {
814 	return (cb->rca & 0x1f) == 0 &&
815 		(cb->roa & 0xfff) == 0 &&
816 		(cb->rla & 0xfff) == 0xfff &&
817 		cb->s == 1 &&
818 		cb->k == 1 &&
819 		cb->h == 0 &&
820 		cb->reserved1 == 0 &&
821 		cb->ps == 1 &&
822 		cb->qs == 0 &&
823 		cb->pc == 1 &&
824 		cb->qc == 0 &&
825 		cb->reserved2 == 0 &&
826 		cb->reserved3 == 0 &&
827 		cb->reserved4 == 0 &&
828 		cb->reserved5 == 0 &&
829 		cb->reserved6 == 0 &&
830 		cb->reserved7 == 0 &&
831 		cb->reserved8 == 0 &&
832 		cb->rla >= cb->roa &&
833 		cb->rca >= cb->roa &&
834 		cb->rca <= cb->rla+1 &&
835 		cb->m < 3;
836 }
837 
838 static int s390_runtime_instr_get(struct task_struct *target,
839 				const struct user_regset *regset,
840 				struct membuf to)
841 {
842 	struct runtime_instr_cb *data = target->thread.ri_cb;
843 
844 	if (!test_facility(64))
845 		return -ENODEV;
846 	if (!data)
847 		return -ENODATA;
848 
849 	return membuf_write(&to, data, sizeof(struct runtime_instr_cb));
850 }
851 
852 static int s390_runtime_instr_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 	struct runtime_instr_cb ri_cb = { }, *data = NULL;
858 	int rc;
859 
860 	if (!test_facility(64))
861 		return -ENODEV;
862 
863 	if (!target->thread.ri_cb) {
864 		data = kzalloc(sizeof(*data), GFP_KERNEL);
865 		if (!data)
866 			return -ENOMEM;
867 	}
868 
869 	if (target->thread.ri_cb) {
870 		if (target == current)
871 			store_runtime_instr_cb(&ri_cb);
872 		else
873 			ri_cb = *target->thread.ri_cb;
874 	}
875 
876 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
877 				&ri_cb, 0, sizeof(struct runtime_instr_cb));
878 	if (rc) {
879 		kfree(data);
880 		return -EFAULT;
881 	}
882 
883 	if (!is_ri_cb_valid(&ri_cb)) {
884 		kfree(data);
885 		return -EINVAL;
886 	}
887 	/*
888 	 * Override access key in any case, since user space should
889 	 * not be able to set it, nor should it care about it.
890 	 */
891 	ri_cb.key = PAGE_DEFAULT_KEY >> 4;
892 	preempt_disable();
893 	if (!target->thread.ri_cb)
894 		target->thread.ri_cb = data;
895 	*target->thread.ri_cb = ri_cb;
896 	if (target == current)
897 		load_runtime_instr_cb(target->thread.ri_cb);
898 	preempt_enable();
899 
900 	return 0;
901 }
902 
903 static const struct user_regset s390_regsets[] = {
904 	{
905 		USER_REGSET_NOTE_TYPE(PRSTATUS),
906 		.n = sizeof(s390_regs) / sizeof(long),
907 		.size = sizeof(long),
908 		.align = sizeof(long),
909 		.regset_get = s390_regs_get,
910 		.set = s390_regs_set,
911 	},
912 	{
913 		USER_REGSET_NOTE_TYPE(PRFPREG),
914 		.n = sizeof(s390_fp_regs) / sizeof(long),
915 		.size = sizeof(long),
916 		.align = sizeof(long),
917 		.regset_get = s390_fpregs_get,
918 		.set = s390_fpregs_set,
919 	},
920 	{
921 		USER_REGSET_NOTE_TYPE(S390_SYSTEM_CALL),
922 		.n = 1,
923 		.size = sizeof(unsigned int),
924 		.align = sizeof(unsigned int),
925 		.regset_get = s390_system_call_get,
926 		.set = s390_system_call_set,
927 	},
928 	{
929 		USER_REGSET_NOTE_TYPE(S390_LAST_BREAK),
930 		.n = 1,
931 		.size = sizeof(long),
932 		.align = sizeof(long),
933 		.regset_get = s390_last_break_get,
934 		.set = s390_last_break_set,
935 	},
936 	{
937 		USER_REGSET_NOTE_TYPE(S390_TDB),
938 		.n = 1,
939 		.size = 256,
940 		.align = 1,
941 		.regset_get = s390_tdb_get,
942 		.set = s390_tdb_set,
943 	},
944 	{
945 		USER_REGSET_NOTE_TYPE(S390_VXRS_LOW),
946 		.n = __NUM_VXRS_LOW,
947 		.size = sizeof(__u64),
948 		.align = sizeof(__u64),
949 		.regset_get = s390_vxrs_low_get,
950 		.set = s390_vxrs_low_set,
951 	},
952 	{
953 		USER_REGSET_NOTE_TYPE(S390_VXRS_HIGH),
954 		.n = __NUM_VXRS_HIGH,
955 		.size = sizeof(__vector128),
956 		.align = sizeof(__vector128),
957 		.regset_get = s390_vxrs_high_get,
958 		.set = s390_vxrs_high_set,
959 	},
960 	{
961 		USER_REGSET_NOTE_TYPE(S390_GS_CB),
962 		.n = sizeof(struct gs_cb) / sizeof(__u64),
963 		.size = sizeof(__u64),
964 		.align = sizeof(__u64),
965 		.regset_get = s390_gs_cb_get,
966 		.set = s390_gs_cb_set,
967 	},
968 	{
969 		USER_REGSET_NOTE_TYPE(S390_GS_BC),
970 		.n = sizeof(struct gs_cb) / sizeof(__u64),
971 		.size = sizeof(__u64),
972 		.align = sizeof(__u64),
973 		.regset_get = s390_gs_bc_get,
974 		.set = s390_gs_bc_set,
975 	},
976 	{
977 		USER_REGSET_NOTE_TYPE(S390_RI_CB),
978 		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
979 		.size = sizeof(__u64),
980 		.align = sizeof(__u64),
981 		.regset_get = s390_runtime_instr_get,
982 		.set = s390_runtime_instr_set,
983 	},
984 };
985 
986 static const struct user_regset_view user_s390_view = {
987 	.name = "s390x",
988 	.e_machine = EM_S390,
989 	.regsets = s390_regsets,
990 	.n = ARRAY_SIZE(s390_regsets)
991 };
992 
993 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
994 {
995 	return &user_s390_view;
996 }
997 
998 static const char *gpr_names[NUM_GPRS] = {
999 	"r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1000 	"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1001 };
1002 
1003 int regs_query_register_offset(const char *name)
1004 {
1005 	unsigned long offset;
1006 
1007 	if (!name || *name != 'r')
1008 		return -EINVAL;
1009 	if (kstrtoul(name + 1, 10, &offset))
1010 		return -EINVAL;
1011 	if (offset >= NUM_GPRS)
1012 		return -EINVAL;
1013 	return offset;
1014 }
1015 
1016 const char *regs_query_register_name(unsigned int offset)
1017 {
1018 	if (offset >= NUM_GPRS)
1019 		return NULL;
1020 	return gpr_names[offset];
1021 }
1022