xref: /openbmc/linux/arch/s390/kernel/ptrace.c (revision 36fe4655)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Ptrace user space interface.
4  *
5  *    Copyright IBM Corp. 1999, 2010
6  *    Author(s): Denis Joseph Barrow
7  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/sched.h>
12 #include <linux/sched/task_stack.h>
13 #include <linux/mm.h>
14 #include <linux/smp.h>
15 #include <linux/errno.h>
16 #include <linux/ptrace.h>
17 #include <linux/user.h>
18 #include <linux/security.h>
19 #include <linux/audit.h>
20 #include <linux/signal.h>
21 #include <linux/elf.h>
22 #include <linux/regset.h>
23 #include <linux/tracehook.h>
24 #include <linux/seccomp.h>
25 #include <linux/compat.h>
26 #include <trace/syscall.h>
27 #include <asm/page.h>
28 #include <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 #define CREATE_TRACE_POINTS
41 #include <trace/events/syscalls.h>
42 
43 void update_cr_regs(struct task_struct *task)
44 {
45 	struct pt_regs *regs = task_pt_regs(task);
46 	struct thread_struct *thread = &task->thread;
47 	struct per_regs old, new;
48 	union ctlreg0 cr0_old, cr0_new;
49 	union ctlreg2 cr2_old, cr2_new;
50 	int cr0_changed, cr2_changed;
51 
52 	__ctl_store(cr0_old.val, 0, 0);
53 	__ctl_store(cr2_old.val, 2, 2);
54 	cr0_new = cr0_old;
55 	cr2_new = cr2_old;
56 	/* Take care of the enable/disable of transactional execution. */
57 	if (MACHINE_HAS_TE) {
58 		/* Set or clear transaction execution TXC bit 8. */
59 		cr0_new.tcx = 1;
60 		if (task->thread.per_flags & PER_FLAG_NO_TE)
61 			cr0_new.tcx = 0;
62 		/* Set or clear transaction execution TDC bits 62 and 63. */
63 		cr2_new.tdc = 0;
64 		if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
65 			if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
66 				cr2_new.tdc = 1;
67 			else
68 				cr2_new.tdc = 2;
69 		}
70 	}
71 	/* Take care of enable/disable of guarded storage. */
72 	if (MACHINE_HAS_GS) {
73 		cr2_new.gse = 0;
74 		if (task->thread.gs_cb)
75 			cr2_new.gse = 1;
76 	}
77 	/* Load control register 0/2 iff changed */
78 	cr0_changed = cr0_new.val != cr0_old.val;
79 	cr2_changed = cr2_new.val != cr2_old.val;
80 	if (cr0_changed)
81 		__ctl_load(cr0_new.val, 0, 0);
82 	if (cr2_changed)
83 		__ctl_load(cr2_new.val, 2, 2);
84 	/* Copy user specified PER registers */
85 	new.control = thread->per_user.control;
86 	new.start = thread->per_user.start;
87 	new.end = thread->per_user.end;
88 
89 	/* merge TIF_SINGLE_STEP into user specified PER registers. */
90 	if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
91 	    test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
92 		if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
93 			new.control |= PER_EVENT_BRANCH;
94 		else
95 			new.control |= PER_EVENT_IFETCH;
96 		new.control |= PER_CONTROL_SUSPENSION;
97 		new.control |= PER_EVENT_TRANSACTION_END;
98 		if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
99 			new.control |= PER_EVENT_IFETCH;
100 		new.start = 0;
101 		new.end = -1UL;
102 	}
103 
104 	/* Take care of the PER enablement bit in the PSW. */
105 	if (!(new.control & PER_EVENT_MASK)) {
106 		regs->psw.mask &= ~PSW_MASK_PER;
107 		return;
108 	}
109 	regs->psw.mask |= PSW_MASK_PER;
110 	__ctl_store(old, 9, 11);
111 	if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
112 		__ctl_load(new, 9, 11);
113 }
114 
115 void user_enable_single_step(struct task_struct *task)
116 {
117 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
118 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
119 }
120 
121 void user_disable_single_step(struct task_struct *task)
122 {
123 	clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
124 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
125 }
126 
127 void user_enable_block_step(struct task_struct *task)
128 {
129 	set_tsk_thread_flag(task, TIF_SINGLE_STEP);
130 	set_tsk_thread_flag(task, TIF_BLOCK_STEP);
131 }
132 
133 /*
134  * Called by kernel/ptrace.c when detaching..
135  *
136  * Clear all debugging related fields.
137  */
138 void ptrace_disable(struct task_struct *task)
139 {
140 	memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
141 	memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
142 	clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
143 	clear_pt_regs_flag(task_pt_regs(task), PIF_PER_TRAP);
144 	task->thread.per_flags = 0;
145 }
146 
147 #define __ADDR_MASK 7
148 
149 static inline unsigned long __peek_user_per(struct task_struct *child,
150 					    addr_t addr)
151 {
152 	struct per_struct_kernel *dummy = NULL;
153 
154 	if (addr == (addr_t) &dummy->cr9)
155 		/* Control bits of the active per set. */
156 		return test_thread_flag(TIF_SINGLE_STEP) ?
157 			PER_EVENT_IFETCH : child->thread.per_user.control;
158 	else if (addr == (addr_t) &dummy->cr10)
159 		/* Start address of the active per set. */
160 		return test_thread_flag(TIF_SINGLE_STEP) ?
161 			0 : child->thread.per_user.start;
162 	else if (addr == (addr_t) &dummy->cr11)
163 		/* End address of the active per set. */
164 		return test_thread_flag(TIF_SINGLE_STEP) ?
165 			-1UL : child->thread.per_user.end;
166 	else if (addr == (addr_t) &dummy->bits)
167 		/* Single-step bit. */
168 		return test_thread_flag(TIF_SINGLE_STEP) ?
169 			(1UL << (BITS_PER_LONG - 1)) : 0;
170 	else if (addr == (addr_t) &dummy->starting_addr)
171 		/* Start address of the user specified per set. */
172 		return child->thread.per_user.start;
173 	else if (addr == (addr_t) &dummy->ending_addr)
174 		/* End address of the user specified per set. */
175 		return child->thread.per_user.end;
176 	else if (addr == (addr_t) &dummy->perc_atmid)
177 		/* PER code, ATMID and AI of the last PER trap */
178 		return (unsigned long)
179 			child->thread.per_event.cause << (BITS_PER_LONG - 16);
180 	else if (addr == (addr_t) &dummy->address)
181 		/* Address of the last PER trap */
182 		return child->thread.per_event.address;
183 	else if (addr == (addr_t) &dummy->access_id)
184 		/* Access id of the last PER trap */
185 		return (unsigned long)
186 			child->thread.per_event.paid << (BITS_PER_LONG - 8);
187 	return 0;
188 }
189 
190 /*
191  * Read the word at offset addr from the user area of a process. The
192  * trouble here is that the information is littered over different
193  * locations. The process registers are found on the kernel stack,
194  * the floating point stuff and the trace settings are stored in
195  * the task structure. In addition the different structures in
196  * struct user contain pad bytes that should be read as zeroes.
197  * Lovely...
198  */
199 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
200 {
201 	struct user *dummy = NULL;
202 	addr_t offset, tmp;
203 
204 	if (addr < (addr_t) &dummy->regs.acrs) {
205 		/*
206 		 * psw and gprs are stored on the stack
207 		 */
208 		tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
209 		if (addr == (addr_t) &dummy->regs.psw.mask) {
210 			/* Return a clean psw mask. */
211 			tmp &= PSW_MASK_USER | PSW_MASK_RI;
212 			tmp |= PSW_USER_BITS;
213 		}
214 
215 	} else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
216 		/*
217 		 * access registers are stored in the thread structure
218 		 */
219 		offset = addr - (addr_t) &dummy->regs.acrs;
220 		/*
221 		 * Very special case: old & broken 64 bit gdb reading
222 		 * from acrs[15]. Result is a 64 bit value. Read the
223 		 * 32 bit acrs[15] value and shift it by 32. Sick...
224 		 */
225 		if (addr == (addr_t) &dummy->regs.acrs[15])
226 			tmp = ((unsigned long) child->thread.acrs[15]) << 32;
227 		else
228 			tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
229 
230 	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
231 		/*
232 		 * orig_gpr2 is stored on the kernel stack
233 		 */
234 		tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
235 
236 	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
237 		/*
238 		 * prevent reads of padding hole between
239 		 * orig_gpr2 and fp_regs on s390.
240 		 */
241 		tmp = 0;
242 
243 	} else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
244 		/*
245 		 * floating point control reg. is in the thread structure
246 		 */
247 		tmp = child->thread.fpu.fpc;
248 		tmp <<= BITS_PER_LONG - 32;
249 
250 	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
251 		/*
252 		 * floating point regs. are either in child->thread.fpu
253 		 * or the child->thread.fpu.vxrs array
254 		 */
255 		offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
256 		if (MACHINE_HAS_VX)
257 			tmp = *(addr_t *)
258 			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
259 		else
260 			tmp = *(addr_t *)
261 			       ((addr_t) child->thread.fpu.fprs + offset);
262 
263 	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
264 		/*
265 		 * Handle access to the per_info structure.
266 		 */
267 		addr -= (addr_t) &dummy->regs.per_info;
268 		tmp = __peek_user_per(child, addr);
269 
270 	} else
271 		tmp = 0;
272 
273 	return tmp;
274 }
275 
276 static int
277 peek_user(struct task_struct *child, addr_t addr, addr_t data)
278 {
279 	addr_t tmp, mask;
280 
281 	/*
282 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
283 	 * an alignment of 4. Programmers from hell...
284 	 */
285 	mask = __ADDR_MASK;
286 	if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
287 	    addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
288 		mask = 3;
289 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
290 		return -EIO;
291 
292 	tmp = __peek_user(child, addr);
293 	return put_user(tmp, (addr_t __user *) data);
294 }
295 
296 static inline void __poke_user_per(struct task_struct *child,
297 				   addr_t addr, addr_t data)
298 {
299 	struct per_struct_kernel *dummy = NULL;
300 
301 	/*
302 	 * There are only three fields in the per_info struct that the
303 	 * debugger user can write to.
304 	 * 1) cr9: the debugger wants to set a new PER event mask
305 	 * 2) starting_addr: the debugger wants to set a new starting
306 	 *    address to use with the PER event mask.
307 	 * 3) ending_addr: the debugger wants to set a new ending
308 	 *    address to use with the PER event mask.
309 	 * The user specified PER event mask and the start and end
310 	 * addresses are used only if single stepping is not in effect.
311 	 * Writes to any other field in per_info are ignored.
312 	 */
313 	if (addr == (addr_t) &dummy->cr9)
314 		/* PER event mask of the user specified per set. */
315 		child->thread.per_user.control =
316 			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
317 	else if (addr == (addr_t) &dummy->starting_addr)
318 		/* Starting address of the user specified per set. */
319 		child->thread.per_user.start = data;
320 	else if (addr == (addr_t) &dummy->ending_addr)
321 		/* Ending address of the user specified per set. */
322 		child->thread.per_user.end = data;
323 }
324 
325 static void fixup_int_code(struct task_struct *child, addr_t data)
326 {
327 	struct pt_regs *regs = task_pt_regs(child);
328 	int ilc = regs->int_code >> 16;
329 	u16 insn;
330 
331 	if (ilc > 6)
332 		return;
333 
334 	if (ptrace_access_vm(child, regs->psw.addr - (regs->int_code >> 16),
335 			&insn, sizeof(insn), FOLL_FORCE) != sizeof(insn))
336 		return;
337 
338 	/* double check that tracee stopped on svc instruction */
339 	if ((insn >> 8) != 0xa)
340 		return;
341 
342 	regs->int_code = 0x20000 | (data & 0xffff);
343 }
344 /*
345  * Write a word to the user area of a process at location addr. This
346  * operation does have an additional problem compared to peek_user.
347  * Stores to the program status word and on the floating point
348  * control register needs to get checked for validity.
349  */
350 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
351 {
352 	struct user *dummy = NULL;
353 	addr_t offset;
354 
355 
356 	if (addr < (addr_t) &dummy->regs.acrs) {
357 		struct pt_regs *regs = task_pt_regs(child);
358 		/*
359 		 * psw and gprs are stored on the stack
360 		 */
361 		if (addr == (addr_t) &dummy->regs.psw.mask) {
362 			unsigned long mask = PSW_MASK_USER;
363 
364 			mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
365 			if ((data ^ PSW_USER_BITS) & ~mask)
366 				/* Invalid psw mask. */
367 				return -EINVAL;
368 			if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
369 				/* Invalid address-space-control bits */
370 				return -EINVAL;
371 			if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
372 				/* Invalid addressing mode bits */
373 				return -EINVAL;
374 		}
375 
376 		if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
377 			addr == offsetof(struct user, regs.gprs[2]))
378 			fixup_int_code(child, data);
379 		*(addr_t *)((addr_t) &regs->psw + addr) = data;
380 
381 	} else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
382 		/*
383 		 * access registers are stored in the thread structure
384 		 */
385 		offset = addr - (addr_t) &dummy->regs.acrs;
386 		/*
387 		 * Very special case: old & broken 64 bit gdb writing
388 		 * to acrs[15] with a 64 bit value. Ignore the lower
389 		 * half of the value and write the upper 32 bit to
390 		 * acrs[15]. Sick...
391 		 */
392 		if (addr == (addr_t) &dummy->regs.acrs[15])
393 			child->thread.acrs[15] = (unsigned int) (data >> 32);
394 		else
395 			*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
396 
397 	} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
398 		/*
399 		 * orig_gpr2 is stored on the kernel stack
400 		 */
401 		task_pt_regs(child)->orig_gpr2 = data;
402 
403 	} else if (addr < (addr_t) &dummy->regs.fp_regs) {
404 		/*
405 		 * prevent writes of padding hole between
406 		 * orig_gpr2 and fp_regs on s390.
407 		 */
408 		return 0;
409 
410 	} else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
411 		/*
412 		 * floating point control reg. is in the thread structure
413 		 */
414 		if ((unsigned int) data != 0 ||
415 		    test_fp_ctl(data >> (BITS_PER_LONG - 32)))
416 			return -EINVAL;
417 		child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
418 
419 	} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
420 		/*
421 		 * floating point regs. are either in child->thread.fpu
422 		 * or the child->thread.fpu.vxrs array
423 		 */
424 		offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
425 		if (MACHINE_HAS_VX)
426 			*(addr_t *)((addr_t)
427 				child->thread.fpu.vxrs + 2*offset) = data;
428 		else
429 			*(addr_t *)((addr_t)
430 				child->thread.fpu.fprs + offset) = data;
431 
432 	} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
433 		/*
434 		 * Handle access to the per_info structure.
435 		 */
436 		addr -= (addr_t) &dummy->regs.per_info;
437 		__poke_user_per(child, addr, data);
438 
439 	}
440 
441 	return 0;
442 }
443 
444 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
445 {
446 	addr_t mask;
447 
448 	/*
449 	 * Stupid gdb peeks/pokes the access registers in 64 bit with
450 	 * an alignment of 4. Programmers from hell indeed...
451 	 */
452 	mask = __ADDR_MASK;
453 	if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
454 	    addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
455 		mask = 3;
456 	if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
457 		return -EIO;
458 
459 	return __poke_user(child, addr, data);
460 }
461 
462 long arch_ptrace(struct task_struct *child, long request,
463 		 unsigned long addr, unsigned long data)
464 {
465 	ptrace_area parea;
466 	int copied, ret;
467 
468 	switch (request) {
469 	case PTRACE_PEEKUSR:
470 		/* read the word at location addr in the USER area. */
471 		return peek_user(child, addr, data);
472 
473 	case PTRACE_POKEUSR:
474 		/* write the word at location addr in the USER area */
475 		return poke_user(child, addr, data);
476 
477 	case PTRACE_PEEKUSR_AREA:
478 	case PTRACE_POKEUSR_AREA:
479 		if (copy_from_user(&parea, (void __force __user *) addr,
480 							sizeof(parea)))
481 			return -EFAULT;
482 		addr = parea.kernel_addr;
483 		data = parea.process_addr;
484 		copied = 0;
485 		while (copied < parea.len) {
486 			if (request == PTRACE_PEEKUSR_AREA)
487 				ret = peek_user(child, addr, data);
488 			else {
489 				addr_t utmp;
490 				if (get_user(utmp,
491 					     (addr_t __force __user *) data))
492 					return -EFAULT;
493 				ret = poke_user(child, addr, utmp);
494 			}
495 			if (ret)
496 				return ret;
497 			addr += sizeof(unsigned long);
498 			data += sizeof(unsigned long);
499 			copied += sizeof(unsigned long);
500 		}
501 		return 0;
502 	case PTRACE_GET_LAST_BREAK:
503 		put_user(child->thread.last_break,
504 			 (unsigned long __user *) data);
505 		return 0;
506 	case PTRACE_ENABLE_TE:
507 		if (!MACHINE_HAS_TE)
508 			return -EIO;
509 		child->thread.per_flags &= ~PER_FLAG_NO_TE;
510 		return 0;
511 	case PTRACE_DISABLE_TE:
512 		if (!MACHINE_HAS_TE)
513 			return -EIO;
514 		child->thread.per_flags |= PER_FLAG_NO_TE;
515 		child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
516 		return 0;
517 	case PTRACE_TE_ABORT_RAND:
518 		if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
519 			return -EIO;
520 		switch (data) {
521 		case 0UL:
522 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
523 			break;
524 		case 1UL:
525 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
526 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
527 			break;
528 		case 2UL:
529 			child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
530 			child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
531 			break;
532 		default:
533 			return -EINVAL;
534 		}
535 		return 0;
536 	default:
537 		return ptrace_request(child, request, addr, data);
538 	}
539 }
540 
541 #ifdef CONFIG_COMPAT
542 /*
543  * Now the fun part starts... a 31 bit program running in the
544  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
545  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
546  * to handle, the difference to the 64 bit versions of the requests
547  * is that the access is done in multiples of 4 byte instead of
548  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
549  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
550  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
551  * is a 31 bit program too, the content of struct user can be
552  * emulated. A 31 bit program peeking into the struct user of
553  * a 64 bit program is a no-no.
554  */
555 
556 /*
557  * Same as peek_user_per but for a 31 bit program.
558  */
559 static inline __u32 __peek_user_per_compat(struct task_struct *child,
560 					   addr_t addr)
561 {
562 	struct compat_per_struct_kernel *dummy32 = NULL;
563 
564 	if (addr == (addr_t) &dummy32->cr9)
565 		/* Control bits of the active per set. */
566 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
567 			PER_EVENT_IFETCH : child->thread.per_user.control;
568 	else if (addr == (addr_t) &dummy32->cr10)
569 		/* Start address of the active per set. */
570 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
571 			0 : child->thread.per_user.start;
572 	else if (addr == (addr_t) &dummy32->cr11)
573 		/* End address of the active per set. */
574 		return test_thread_flag(TIF_SINGLE_STEP) ?
575 			PSW32_ADDR_INSN : child->thread.per_user.end;
576 	else if (addr == (addr_t) &dummy32->bits)
577 		/* Single-step bit. */
578 		return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
579 			0x80000000 : 0;
580 	else if (addr == (addr_t) &dummy32->starting_addr)
581 		/* Start address of the user specified per set. */
582 		return (__u32) child->thread.per_user.start;
583 	else if (addr == (addr_t) &dummy32->ending_addr)
584 		/* End address of the user specified per set. */
585 		return (__u32) child->thread.per_user.end;
586 	else if (addr == (addr_t) &dummy32->perc_atmid)
587 		/* PER code, ATMID and AI of the last PER trap */
588 		return (__u32) child->thread.per_event.cause << 16;
589 	else if (addr == (addr_t) &dummy32->address)
590 		/* Address of the last PER trap */
591 		return (__u32) child->thread.per_event.address;
592 	else if (addr == (addr_t) &dummy32->access_id)
593 		/* Access id of the last PER trap */
594 		return (__u32) child->thread.per_event.paid << 24;
595 	return 0;
596 }
597 
598 /*
599  * Same as peek_user but for a 31 bit program.
600  */
601 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
602 {
603 	struct compat_user *dummy32 = NULL;
604 	addr_t offset;
605 	__u32 tmp;
606 
607 	if (addr < (addr_t) &dummy32->regs.acrs) {
608 		struct pt_regs *regs = task_pt_regs(child);
609 		/*
610 		 * psw and gprs are stored on the stack
611 		 */
612 		if (addr == (addr_t) &dummy32->regs.psw.mask) {
613 			/* Fake a 31 bit psw mask. */
614 			tmp = (__u32)(regs->psw.mask >> 32);
615 			tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
616 			tmp |= PSW32_USER_BITS;
617 		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
618 			/* Fake a 31 bit psw address. */
619 			tmp = (__u32) regs->psw.addr |
620 				(__u32)(regs->psw.mask & PSW_MASK_BA);
621 		} else {
622 			/* gpr 0-15 */
623 			tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
624 		}
625 	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
626 		/*
627 		 * access registers are stored in the thread structure
628 		 */
629 		offset = addr - (addr_t) &dummy32->regs.acrs;
630 		tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
631 
632 	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
633 		/*
634 		 * orig_gpr2 is stored on the kernel stack
635 		 */
636 		tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
637 
638 	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
639 		/*
640 		 * prevent reads of padding hole between
641 		 * orig_gpr2 and fp_regs on s390.
642 		 */
643 		tmp = 0;
644 
645 	} else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
646 		/*
647 		 * floating point control reg. is in the thread structure
648 		 */
649 		tmp = child->thread.fpu.fpc;
650 
651 	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
652 		/*
653 		 * floating point regs. are either in child->thread.fpu
654 		 * or the child->thread.fpu.vxrs array
655 		 */
656 		offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
657 		if (MACHINE_HAS_VX)
658 			tmp = *(__u32 *)
659 			       ((addr_t) child->thread.fpu.vxrs + 2*offset);
660 		else
661 			tmp = *(__u32 *)
662 			       ((addr_t) child->thread.fpu.fprs + offset);
663 
664 	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
665 		/*
666 		 * Handle access to the per_info structure.
667 		 */
668 		addr -= (addr_t) &dummy32->regs.per_info;
669 		tmp = __peek_user_per_compat(child, addr);
670 
671 	} else
672 		tmp = 0;
673 
674 	return tmp;
675 }
676 
677 static int peek_user_compat(struct task_struct *child,
678 			    addr_t addr, addr_t data)
679 {
680 	__u32 tmp;
681 
682 	if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
683 		return -EIO;
684 
685 	tmp = __peek_user_compat(child, addr);
686 	return put_user(tmp, (__u32 __user *) data);
687 }
688 
689 /*
690  * Same as poke_user_per but for a 31 bit program.
691  */
692 static inline void __poke_user_per_compat(struct task_struct *child,
693 					  addr_t addr, __u32 data)
694 {
695 	struct compat_per_struct_kernel *dummy32 = NULL;
696 
697 	if (addr == (addr_t) &dummy32->cr9)
698 		/* PER event mask of the user specified per set. */
699 		child->thread.per_user.control =
700 			data & (PER_EVENT_MASK | PER_CONTROL_MASK);
701 	else if (addr == (addr_t) &dummy32->starting_addr)
702 		/* Starting address of the user specified per set. */
703 		child->thread.per_user.start = data;
704 	else if (addr == (addr_t) &dummy32->ending_addr)
705 		/* Ending address of the user specified per set. */
706 		child->thread.per_user.end = data;
707 }
708 
709 /*
710  * Same as poke_user but for a 31 bit program.
711  */
712 static int __poke_user_compat(struct task_struct *child,
713 			      addr_t addr, addr_t data)
714 {
715 	struct compat_user *dummy32 = NULL;
716 	__u32 tmp = (__u32) data;
717 	addr_t offset;
718 
719 	if (addr < (addr_t) &dummy32->regs.acrs) {
720 		struct pt_regs *regs = task_pt_regs(child);
721 		/*
722 		 * psw, gprs, acrs and orig_gpr2 are stored on the stack
723 		 */
724 		if (addr == (addr_t) &dummy32->regs.psw.mask) {
725 			__u32 mask = PSW32_MASK_USER;
726 
727 			mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
728 			/* Build a 64 bit psw mask from 31 bit mask. */
729 			if ((tmp ^ PSW32_USER_BITS) & ~mask)
730 				/* Invalid psw mask. */
731 				return -EINVAL;
732 			if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
733 				/* Invalid address-space-control bits */
734 				return -EINVAL;
735 			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
736 				(regs->psw.mask & PSW_MASK_BA) |
737 				(__u64)(tmp & mask) << 32;
738 		} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
739 			/* Build a 64 bit psw address from 31 bit address. */
740 			regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
741 			/* Transfer 31 bit amode bit to psw mask. */
742 			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
743 				(__u64)(tmp & PSW32_ADDR_AMODE);
744 		} else {
745 
746 			if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
747 				addr == offsetof(struct compat_user, regs.gprs[2]))
748 				fixup_int_code(child, data);
749 			/* gpr 0-15 */
750 			*(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
751 		}
752 	} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
753 		/*
754 		 * access registers are stored in the thread structure
755 		 */
756 		offset = addr - (addr_t) &dummy32->regs.acrs;
757 		*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
758 
759 	} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
760 		/*
761 		 * orig_gpr2 is stored on the kernel stack
762 		 */
763 		*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
764 
765 	} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
766 		/*
767 		 * prevent writess of padding hole between
768 		 * orig_gpr2 and fp_regs on s390.
769 		 */
770 		return 0;
771 
772 	} else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
773 		/*
774 		 * floating point control reg. is in the thread structure
775 		 */
776 		if (test_fp_ctl(tmp))
777 			return -EINVAL;
778 		child->thread.fpu.fpc = data;
779 
780 	} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
781 		/*
782 		 * floating point regs. are either in child->thread.fpu
783 		 * or the child->thread.fpu.vxrs array
784 		 */
785 		offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
786 		if (MACHINE_HAS_VX)
787 			*(__u32 *)((addr_t)
788 				child->thread.fpu.vxrs + 2*offset) = tmp;
789 		else
790 			*(__u32 *)((addr_t)
791 				child->thread.fpu.fprs + offset) = tmp;
792 
793 	} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
794 		/*
795 		 * Handle access to the per_info structure.
796 		 */
797 		addr -= (addr_t) &dummy32->regs.per_info;
798 		__poke_user_per_compat(child, addr, data);
799 	}
800 
801 	return 0;
802 }
803 
804 static int poke_user_compat(struct task_struct *child,
805 			    addr_t addr, addr_t data)
806 {
807 	if (!is_compat_task() || (addr & 3) ||
808 	    addr > sizeof(struct compat_user) - 3)
809 		return -EIO;
810 
811 	return __poke_user_compat(child, addr, data);
812 }
813 
814 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
815 			compat_ulong_t caddr, compat_ulong_t cdata)
816 {
817 	unsigned long addr = caddr;
818 	unsigned long data = cdata;
819 	compat_ptrace_area parea;
820 	int copied, ret;
821 
822 	switch (request) {
823 	case PTRACE_PEEKUSR:
824 		/* read the word at location addr in the USER area. */
825 		return peek_user_compat(child, addr, data);
826 
827 	case PTRACE_POKEUSR:
828 		/* write the word at location addr in the USER area */
829 		return poke_user_compat(child, addr, data);
830 
831 	case PTRACE_PEEKUSR_AREA:
832 	case PTRACE_POKEUSR_AREA:
833 		if (copy_from_user(&parea, (void __force __user *) addr,
834 							sizeof(parea)))
835 			return -EFAULT;
836 		addr = parea.kernel_addr;
837 		data = parea.process_addr;
838 		copied = 0;
839 		while (copied < parea.len) {
840 			if (request == PTRACE_PEEKUSR_AREA)
841 				ret = peek_user_compat(child, addr, data);
842 			else {
843 				__u32 utmp;
844 				if (get_user(utmp,
845 					     (__u32 __force __user *) data))
846 					return -EFAULT;
847 				ret = poke_user_compat(child, addr, utmp);
848 			}
849 			if (ret)
850 				return ret;
851 			addr += sizeof(unsigned int);
852 			data += sizeof(unsigned int);
853 			copied += sizeof(unsigned int);
854 		}
855 		return 0;
856 	case PTRACE_GET_LAST_BREAK:
857 		put_user(child->thread.last_break,
858 			 (unsigned int __user *) data);
859 		return 0;
860 	}
861 	return compat_ptrace_request(child, request, addr, data);
862 }
863 #endif
864 
865 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
866 {
867 	unsigned long mask = -1UL;
868 	long ret = -1;
869 
870 	if (is_compat_task())
871 		mask = 0xffffffff;
872 
873 	/*
874 	 * The sysc_tracesys code in entry.S stored the system
875 	 * call number to gprs[2].
876 	 */
877 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
878 	    tracehook_report_syscall_entry(regs)) {
879 		/*
880 		 * Tracing decided this syscall should not happen. Skip
881 		 * the system call and the system call restart handling.
882 		 */
883 		goto skip;
884 	}
885 
886 #ifdef CONFIG_SECCOMP
887 	/* Do the secure computing check after ptrace. */
888 	if (unlikely(test_thread_flag(TIF_SECCOMP))) {
889 		struct seccomp_data sd;
890 
891 		if (is_compat_task()) {
892 			sd.instruction_pointer = regs->psw.addr & 0x7fffffff;
893 			sd.arch = AUDIT_ARCH_S390;
894 		} else {
895 			sd.instruction_pointer = regs->psw.addr;
896 			sd.arch = AUDIT_ARCH_S390X;
897 		}
898 
899 		sd.nr = regs->int_code & 0xffff;
900 		sd.args[0] = regs->orig_gpr2 & mask;
901 		sd.args[1] = regs->gprs[3] & mask;
902 		sd.args[2] = regs->gprs[4] & mask;
903 		sd.args[3] = regs->gprs[5] & mask;
904 		sd.args[4] = regs->gprs[6] & mask;
905 		sd.args[5] = regs->gprs[7] & mask;
906 
907 		if (__secure_computing(&sd) == -1)
908 			goto skip;
909 	}
910 #endif /* CONFIG_SECCOMP */
911 
912 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
913 		trace_sys_enter(regs, regs->int_code & 0xffff);
914 
915 
916 	audit_syscall_entry(regs->int_code & 0xffff, regs->orig_gpr2 & mask,
917 			    regs->gprs[3] &mask, regs->gprs[4] &mask,
918 			    regs->gprs[5] &mask);
919 
920 	if ((signed long)regs->gprs[2] >= NR_syscalls) {
921 		regs->gprs[2] = -ENOSYS;
922 		ret = -ENOSYS;
923 	}
924 	return regs->gprs[2];
925 skip:
926 	clear_pt_regs_flag(regs, PIF_SYSCALL);
927 	return ret;
928 }
929 
930 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
931 {
932 	audit_syscall_exit(regs);
933 
934 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
935 		trace_sys_exit(regs, regs->gprs[2]);
936 
937 	if (test_thread_flag(TIF_SYSCALL_TRACE))
938 		tracehook_report_syscall_exit(regs, 0);
939 }
940 
941 /*
942  * user_regset definitions.
943  */
944 
945 static int s390_regs_get(struct task_struct *target,
946 			 const struct user_regset *regset,
947 			 struct membuf to)
948 {
949 	unsigned pos;
950 	if (target == current)
951 		save_access_regs(target->thread.acrs);
952 
953 	for (pos = 0; pos < sizeof(s390_regs); pos += sizeof(long))
954 		membuf_store(&to, __peek_user(target, pos));
955 	return 0;
956 }
957 
958 static int s390_regs_set(struct task_struct *target,
959 			 const struct user_regset *regset,
960 			 unsigned int pos, unsigned int count,
961 			 const void *kbuf, const void __user *ubuf)
962 {
963 	int rc = 0;
964 
965 	if (target == current)
966 		save_access_regs(target->thread.acrs);
967 
968 	if (kbuf) {
969 		const unsigned long *k = kbuf;
970 		while (count > 0 && !rc) {
971 			rc = __poke_user(target, pos, *k++);
972 			count -= sizeof(*k);
973 			pos += sizeof(*k);
974 		}
975 	} else {
976 		const unsigned long  __user *u = ubuf;
977 		while (count > 0 && !rc) {
978 			unsigned long word;
979 			rc = __get_user(word, u++);
980 			if (rc)
981 				break;
982 			rc = __poke_user(target, pos, word);
983 			count -= sizeof(*u);
984 			pos += sizeof(*u);
985 		}
986 	}
987 
988 	if (rc == 0 && target == current)
989 		restore_access_regs(target->thread.acrs);
990 
991 	return rc;
992 }
993 
994 static int s390_fpregs_get(struct task_struct *target,
995 			   const struct user_regset *regset,
996 			   struct membuf to)
997 {
998 	_s390_fp_regs fp_regs;
999 
1000 	if (target == current)
1001 		save_fpu_regs();
1002 
1003 	fp_regs.fpc = target->thread.fpu.fpc;
1004 	fpregs_store(&fp_regs, &target->thread.fpu);
1005 
1006 	return membuf_write(&to, &fp_regs, sizeof(fp_regs));
1007 }
1008 
1009 static int s390_fpregs_set(struct task_struct *target,
1010 			   const struct user_regset *regset, unsigned int pos,
1011 			   unsigned int count, const void *kbuf,
1012 			   const void __user *ubuf)
1013 {
1014 	int rc = 0;
1015 	freg_t fprs[__NUM_FPRS];
1016 
1017 	if (target == current)
1018 		save_fpu_regs();
1019 
1020 	if (MACHINE_HAS_VX)
1021 		convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
1022 	else
1023 		memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
1024 
1025 	/* If setting FPC, must validate it first. */
1026 	if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
1027 		u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
1028 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
1029 					0, offsetof(s390_fp_regs, fprs));
1030 		if (rc)
1031 			return rc;
1032 		if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
1033 			return -EINVAL;
1034 		target->thread.fpu.fpc = ufpc[0];
1035 	}
1036 
1037 	if (rc == 0 && count > 0)
1038 		rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1039 					fprs, offsetof(s390_fp_regs, fprs), -1);
1040 	if (rc)
1041 		return rc;
1042 
1043 	if (MACHINE_HAS_VX)
1044 		convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
1045 	else
1046 		memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
1047 
1048 	return rc;
1049 }
1050 
1051 static int s390_last_break_get(struct task_struct *target,
1052 			       const struct user_regset *regset,
1053 			       struct membuf to)
1054 {
1055 	return membuf_store(&to, target->thread.last_break);
1056 }
1057 
1058 static int s390_last_break_set(struct task_struct *target,
1059 			       const struct user_regset *regset,
1060 			       unsigned int pos, unsigned int count,
1061 			       const void *kbuf, const void __user *ubuf)
1062 {
1063 	return 0;
1064 }
1065 
1066 static int s390_tdb_get(struct task_struct *target,
1067 			const struct user_regset *regset,
1068 			struct membuf to)
1069 {
1070 	struct pt_regs *regs = task_pt_regs(target);
1071 
1072 	if (!(regs->int_code & 0x200))
1073 		return -ENODATA;
1074 	return membuf_write(&to, target->thread.trap_tdb, 256);
1075 }
1076 
1077 static int s390_tdb_set(struct task_struct *target,
1078 			const struct user_regset *regset,
1079 			unsigned int pos, unsigned int count,
1080 			const void *kbuf, const void __user *ubuf)
1081 {
1082 	return 0;
1083 }
1084 
1085 static int s390_vxrs_low_get(struct task_struct *target,
1086 			     const struct user_regset *regset,
1087 			     struct membuf to)
1088 {
1089 	__u64 vxrs[__NUM_VXRS_LOW];
1090 	int i;
1091 
1092 	if (!MACHINE_HAS_VX)
1093 		return -ENODEV;
1094 	if (target == current)
1095 		save_fpu_regs();
1096 	for (i = 0; i < __NUM_VXRS_LOW; i++)
1097 		vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1098 	return membuf_write(&to, vxrs, sizeof(vxrs));
1099 }
1100 
1101 static int s390_vxrs_low_set(struct task_struct *target,
1102 			     const struct user_regset *regset,
1103 			     unsigned int pos, unsigned int count,
1104 			     const void *kbuf, const void __user *ubuf)
1105 {
1106 	__u64 vxrs[__NUM_VXRS_LOW];
1107 	int i, rc;
1108 
1109 	if (!MACHINE_HAS_VX)
1110 		return -ENODEV;
1111 	if (target == current)
1112 		save_fpu_regs();
1113 
1114 	for (i = 0; i < __NUM_VXRS_LOW; i++)
1115 		vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1116 
1117 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1118 	if (rc == 0)
1119 		for (i = 0; i < __NUM_VXRS_LOW; i++)
1120 			*((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1121 
1122 	return rc;
1123 }
1124 
1125 static int s390_vxrs_high_get(struct task_struct *target,
1126 			      const struct user_regset *regset,
1127 			      struct membuf to)
1128 {
1129 	if (!MACHINE_HAS_VX)
1130 		return -ENODEV;
1131 	if (target == current)
1132 		save_fpu_regs();
1133 	return membuf_write(&to, target->thread.fpu.vxrs + __NUM_VXRS_LOW,
1134 			    __NUM_VXRS_HIGH * sizeof(__vector128));
1135 }
1136 
1137 static int s390_vxrs_high_set(struct task_struct *target,
1138 			      const struct user_regset *regset,
1139 			      unsigned int pos, unsigned int count,
1140 			      const void *kbuf, const void __user *ubuf)
1141 {
1142 	int rc;
1143 
1144 	if (!MACHINE_HAS_VX)
1145 		return -ENODEV;
1146 	if (target == current)
1147 		save_fpu_regs();
1148 
1149 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1150 				target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1151 	return rc;
1152 }
1153 
1154 static int s390_system_call_get(struct task_struct *target,
1155 				const struct user_regset *regset,
1156 				struct membuf to)
1157 {
1158 	return membuf_store(&to, target->thread.system_call);
1159 }
1160 
1161 static int s390_system_call_set(struct task_struct *target,
1162 				const struct user_regset *regset,
1163 				unsigned int pos, unsigned int count,
1164 				const void *kbuf, const void __user *ubuf)
1165 {
1166 	unsigned int *data = &target->thread.system_call;
1167 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1168 				  data, 0, sizeof(unsigned int));
1169 }
1170 
1171 static int s390_gs_cb_get(struct task_struct *target,
1172 			  const struct user_regset *regset,
1173 			  struct membuf to)
1174 {
1175 	struct gs_cb *data = target->thread.gs_cb;
1176 
1177 	if (!MACHINE_HAS_GS)
1178 		return -ENODEV;
1179 	if (!data)
1180 		return -ENODATA;
1181 	if (target == current)
1182 		save_gs_cb(data);
1183 	return membuf_write(&to, data, sizeof(struct gs_cb));
1184 }
1185 
1186 static int s390_gs_cb_set(struct task_struct *target,
1187 			  const struct user_regset *regset,
1188 			  unsigned int pos, unsigned int count,
1189 			  const void *kbuf, const void __user *ubuf)
1190 {
1191 	struct gs_cb gs_cb = { }, *data = NULL;
1192 	int rc;
1193 
1194 	if (!MACHINE_HAS_GS)
1195 		return -ENODEV;
1196 	if (!target->thread.gs_cb) {
1197 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1198 		if (!data)
1199 			return -ENOMEM;
1200 	}
1201 	if (!target->thread.gs_cb)
1202 		gs_cb.gsd = 25;
1203 	else if (target == current)
1204 		save_gs_cb(&gs_cb);
1205 	else
1206 		gs_cb = *target->thread.gs_cb;
1207 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1208 				&gs_cb, 0, sizeof(gs_cb));
1209 	if (rc) {
1210 		kfree(data);
1211 		return -EFAULT;
1212 	}
1213 	preempt_disable();
1214 	if (!target->thread.gs_cb)
1215 		target->thread.gs_cb = data;
1216 	*target->thread.gs_cb = gs_cb;
1217 	if (target == current) {
1218 		__ctl_set_bit(2, 4);
1219 		restore_gs_cb(target->thread.gs_cb);
1220 	}
1221 	preempt_enable();
1222 	return rc;
1223 }
1224 
1225 static int s390_gs_bc_get(struct task_struct *target,
1226 			  const struct user_regset *regset,
1227 			  struct membuf to)
1228 {
1229 	struct gs_cb *data = target->thread.gs_bc_cb;
1230 
1231 	if (!MACHINE_HAS_GS)
1232 		return -ENODEV;
1233 	if (!data)
1234 		return -ENODATA;
1235 	return membuf_write(&to, data, sizeof(struct gs_cb));
1236 }
1237 
1238 static int s390_gs_bc_set(struct task_struct *target,
1239 			  const struct user_regset *regset,
1240 			  unsigned int pos, unsigned int count,
1241 			  const void *kbuf, const void __user *ubuf)
1242 {
1243 	struct gs_cb *data = target->thread.gs_bc_cb;
1244 
1245 	if (!MACHINE_HAS_GS)
1246 		return -ENODEV;
1247 	if (!data) {
1248 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1249 		if (!data)
1250 			return -ENOMEM;
1251 		target->thread.gs_bc_cb = data;
1252 	}
1253 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1254 				  data, 0, sizeof(struct gs_cb));
1255 }
1256 
1257 static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1258 {
1259 	return (cb->rca & 0x1f) == 0 &&
1260 		(cb->roa & 0xfff) == 0 &&
1261 		(cb->rla & 0xfff) == 0xfff &&
1262 		cb->s == 1 &&
1263 		cb->k == 1 &&
1264 		cb->h == 0 &&
1265 		cb->reserved1 == 0 &&
1266 		cb->ps == 1 &&
1267 		cb->qs == 0 &&
1268 		cb->pc == 1 &&
1269 		cb->qc == 0 &&
1270 		cb->reserved2 == 0 &&
1271 		cb->reserved3 == 0 &&
1272 		cb->reserved4 == 0 &&
1273 		cb->reserved5 == 0 &&
1274 		cb->reserved6 == 0 &&
1275 		cb->reserved7 == 0 &&
1276 		cb->reserved8 == 0 &&
1277 		cb->rla >= cb->roa &&
1278 		cb->rca >= cb->roa &&
1279 		cb->rca <= cb->rla+1 &&
1280 		cb->m < 3;
1281 }
1282 
1283 static int s390_runtime_instr_get(struct task_struct *target,
1284 				const struct user_regset *regset,
1285 				struct membuf to)
1286 {
1287 	struct runtime_instr_cb *data = target->thread.ri_cb;
1288 
1289 	if (!test_facility(64))
1290 		return -ENODEV;
1291 	if (!data)
1292 		return -ENODATA;
1293 
1294 	return membuf_write(&to, data, sizeof(struct runtime_instr_cb));
1295 }
1296 
1297 static int s390_runtime_instr_set(struct task_struct *target,
1298 				  const struct user_regset *regset,
1299 				  unsigned int pos, unsigned int count,
1300 				  const void *kbuf, const void __user *ubuf)
1301 {
1302 	struct runtime_instr_cb ri_cb = { }, *data = NULL;
1303 	int rc;
1304 
1305 	if (!test_facility(64))
1306 		return -ENODEV;
1307 
1308 	if (!target->thread.ri_cb) {
1309 		data = kzalloc(sizeof(*data), GFP_KERNEL);
1310 		if (!data)
1311 			return -ENOMEM;
1312 	}
1313 
1314 	if (target->thread.ri_cb) {
1315 		if (target == current)
1316 			store_runtime_instr_cb(&ri_cb);
1317 		else
1318 			ri_cb = *target->thread.ri_cb;
1319 	}
1320 
1321 	rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1322 				&ri_cb, 0, sizeof(struct runtime_instr_cb));
1323 	if (rc) {
1324 		kfree(data);
1325 		return -EFAULT;
1326 	}
1327 
1328 	if (!is_ri_cb_valid(&ri_cb)) {
1329 		kfree(data);
1330 		return -EINVAL;
1331 	}
1332 	/*
1333 	 * Override access key in any case, since user space should
1334 	 * not be able to set it, nor should it care about it.
1335 	 */
1336 	ri_cb.key = PAGE_DEFAULT_KEY >> 4;
1337 	preempt_disable();
1338 	if (!target->thread.ri_cb)
1339 		target->thread.ri_cb = data;
1340 	*target->thread.ri_cb = ri_cb;
1341 	if (target == current)
1342 		load_runtime_instr_cb(target->thread.ri_cb);
1343 	preempt_enable();
1344 
1345 	return 0;
1346 }
1347 
1348 static const struct user_regset s390_regsets[] = {
1349 	{
1350 		.core_note_type = NT_PRSTATUS,
1351 		.n = sizeof(s390_regs) / sizeof(long),
1352 		.size = sizeof(long),
1353 		.align = sizeof(long),
1354 		.regset_get = s390_regs_get,
1355 		.set = s390_regs_set,
1356 	},
1357 	{
1358 		.core_note_type = NT_PRFPREG,
1359 		.n = sizeof(s390_fp_regs) / sizeof(long),
1360 		.size = sizeof(long),
1361 		.align = sizeof(long),
1362 		.regset_get = s390_fpregs_get,
1363 		.set = s390_fpregs_set,
1364 	},
1365 	{
1366 		.core_note_type = NT_S390_SYSTEM_CALL,
1367 		.n = 1,
1368 		.size = sizeof(unsigned int),
1369 		.align = sizeof(unsigned int),
1370 		.regset_get = s390_system_call_get,
1371 		.set = s390_system_call_set,
1372 	},
1373 	{
1374 		.core_note_type = NT_S390_LAST_BREAK,
1375 		.n = 1,
1376 		.size = sizeof(long),
1377 		.align = sizeof(long),
1378 		.regset_get = s390_last_break_get,
1379 		.set = s390_last_break_set,
1380 	},
1381 	{
1382 		.core_note_type = NT_S390_TDB,
1383 		.n = 1,
1384 		.size = 256,
1385 		.align = 1,
1386 		.regset_get = s390_tdb_get,
1387 		.set = s390_tdb_set,
1388 	},
1389 	{
1390 		.core_note_type = NT_S390_VXRS_LOW,
1391 		.n = __NUM_VXRS_LOW,
1392 		.size = sizeof(__u64),
1393 		.align = sizeof(__u64),
1394 		.regset_get = s390_vxrs_low_get,
1395 		.set = s390_vxrs_low_set,
1396 	},
1397 	{
1398 		.core_note_type = NT_S390_VXRS_HIGH,
1399 		.n = __NUM_VXRS_HIGH,
1400 		.size = sizeof(__vector128),
1401 		.align = sizeof(__vector128),
1402 		.regset_get = s390_vxrs_high_get,
1403 		.set = s390_vxrs_high_set,
1404 	},
1405 	{
1406 		.core_note_type = NT_S390_GS_CB,
1407 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1408 		.size = sizeof(__u64),
1409 		.align = sizeof(__u64),
1410 		.regset_get = s390_gs_cb_get,
1411 		.set = s390_gs_cb_set,
1412 	},
1413 	{
1414 		.core_note_type = NT_S390_GS_BC,
1415 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1416 		.size = sizeof(__u64),
1417 		.align = sizeof(__u64),
1418 		.regset_get = s390_gs_bc_get,
1419 		.set = s390_gs_bc_set,
1420 	},
1421 	{
1422 		.core_note_type = NT_S390_RI_CB,
1423 		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1424 		.size = sizeof(__u64),
1425 		.align = sizeof(__u64),
1426 		.regset_get = s390_runtime_instr_get,
1427 		.set = s390_runtime_instr_set,
1428 	},
1429 };
1430 
1431 static const struct user_regset_view user_s390_view = {
1432 	.name = "s390x",
1433 	.e_machine = EM_S390,
1434 	.regsets = s390_regsets,
1435 	.n = ARRAY_SIZE(s390_regsets)
1436 };
1437 
1438 #ifdef CONFIG_COMPAT
1439 static int s390_compat_regs_get(struct task_struct *target,
1440 				const struct user_regset *regset,
1441 				struct membuf to)
1442 {
1443 	unsigned n;
1444 
1445 	if (target == current)
1446 		save_access_regs(target->thread.acrs);
1447 
1448 	for (n = 0; n < sizeof(s390_compat_regs); n += sizeof(compat_ulong_t))
1449 		membuf_store(&to, __peek_user_compat(target, n));
1450 	return 0;
1451 }
1452 
1453 static int s390_compat_regs_set(struct task_struct *target,
1454 				const struct user_regset *regset,
1455 				unsigned int pos, unsigned int count,
1456 				const void *kbuf, const void __user *ubuf)
1457 {
1458 	int rc = 0;
1459 
1460 	if (target == current)
1461 		save_access_regs(target->thread.acrs);
1462 
1463 	if (kbuf) {
1464 		const compat_ulong_t *k = kbuf;
1465 		while (count > 0 && !rc) {
1466 			rc = __poke_user_compat(target, pos, *k++);
1467 			count -= sizeof(*k);
1468 			pos += sizeof(*k);
1469 		}
1470 	} else {
1471 		const compat_ulong_t  __user *u = ubuf;
1472 		while (count > 0 && !rc) {
1473 			compat_ulong_t word;
1474 			rc = __get_user(word, u++);
1475 			if (rc)
1476 				break;
1477 			rc = __poke_user_compat(target, pos, word);
1478 			count -= sizeof(*u);
1479 			pos += sizeof(*u);
1480 		}
1481 	}
1482 
1483 	if (rc == 0 && target == current)
1484 		restore_access_regs(target->thread.acrs);
1485 
1486 	return rc;
1487 }
1488 
1489 static int s390_compat_regs_high_get(struct task_struct *target,
1490 				     const struct user_regset *regset,
1491 				     struct membuf to)
1492 {
1493 	compat_ulong_t *gprs_high;
1494 	int i;
1495 
1496 	gprs_high = (compat_ulong_t *)task_pt_regs(target)->gprs;
1497 	for (i = 0; i < NUM_GPRS; i++, gprs_high += 2)
1498 		membuf_store(&to, *gprs_high);
1499 	return 0;
1500 }
1501 
1502 static int s390_compat_regs_high_set(struct task_struct *target,
1503 				     const struct user_regset *regset,
1504 				     unsigned int pos, unsigned int count,
1505 				     const void *kbuf, const void __user *ubuf)
1506 {
1507 	compat_ulong_t *gprs_high;
1508 	int rc = 0;
1509 
1510 	gprs_high = (compat_ulong_t *)
1511 		&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1512 	if (kbuf) {
1513 		const compat_ulong_t *k = kbuf;
1514 		while (count > 0) {
1515 			*gprs_high = *k++;
1516 			*gprs_high += 2;
1517 			count -= sizeof(*k);
1518 		}
1519 	} else {
1520 		const compat_ulong_t  __user *u = ubuf;
1521 		while (count > 0 && !rc) {
1522 			unsigned long word;
1523 			rc = __get_user(word, u++);
1524 			if (rc)
1525 				break;
1526 			*gprs_high = word;
1527 			*gprs_high += 2;
1528 			count -= sizeof(*u);
1529 		}
1530 	}
1531 
1532 	return rc;
1533 }
1534 
1535 static int s390_compat_last_break_get(struct task_struct *target,
1536 				      const struct user_regset *regset,
1537 				      struct membuf to)
1538 {
1539 	compat_ulong_t last_break = target->thread.last_break;
1540 
1541 	return membuf_store(&to, (unsigned long)last_break);
1542 }
1543 
1544 static int s390_compat_last_break_set(struct task_struct *target,
1545 				      const struct user_regset *regset,
1546 				      unsigned int pos, unsigned int count,
1547 				      const void *kbuf, const void __user *ubuf)
1548 {
1549 	return 0;
1550 }
1551 
1552 static const struct user_regset s390_compat_regsets[] = {
1553 	{
1554 		.core_note_type = NT_PRSTATUS,
1555 		.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1556 		.size = sizeof(compat_long_t),
1557 		.align = sizeof(compat_long_t),
1558 		.regset_get = s390_compat_regs_get,
1559 		.set = s390_compat_regs_set,
1560 	},
1561 	{
1562 		.core_note_type = NT_PRFPREG,
1563 		.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1564 		.size = sizeof(compat_long_t),
1565 		.align = sizeof(compat_long_t),
1566 		.regset_get = s390_fpregs_get,
1567 		.set = s390_fpregs_set,
1568 	},
1569 	{
1570 		.core_note_type = NT_S390_SYSTEM_CALL,
1571 		.n = 1,
1572 		.size = sizeof(compat_uint_t),
1573 		.align = sizeof(compat_uint_t),
1574 		.regset_get = s390_system_call_get,
1575 		.set = s390_system_call_set,
1576 	},
1577 	{
1578 		.core_note_type = NT_S390_LAST_BREAK,
1579 		.n = 1,
1580 		.size = sizeof(long),
1581 		.align = sizeof(long),
1582 		.regset_get = s390_compat_last_break_get,
1583 		.set = s390_compat_last_break_set,
1584 	},
1585 	{
1586 		.core_note_type = NT_S390_TDB,
1587 		.n = 1,
1588 		.size = 256,
1589 		.align = 1,
1590 		.regset_get = s390_tdb_get,
1591 		.set = s390_tdb_set,
1592 	},
1593 	{
1594 		.core_note_type = NT_S390_VXRS_LOW,
1595 		.n = __NUM_VXRS_LOW,
1596 		.size = sizeof(__u64),
1597 		.align = sizeof(__u64),
1598 		.regset_get = s390_vxrs_low_get,
1599 		.set = s390_vxrs_low_set,
1600 	},
1601 	{
1602 		.core_note_type = NT_S390_VXRS_HIGH,
1603 		.n = __NUM_VXRS_HIGH,
1604 		.size = sizeof(__vector128),
1605 		.align = sizeof(__vector128),
1606 		.regset_get = s390_vxrs_high_get,
1607 		.set = s390_vxrs_high_set,
1608 	},
1609 	{
1610 		.core_note_type = NT_S390_HIGH_GPRS,
1611 		.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1612 		.size = sizeof(compat_long_t),
1613 		.align = sizeof(compat_long_t),
1614 		.regset_get = s390_compat_regs_high_get,
1615 		.set = s390_compat_regs_high_set,
1616 	},
1617 	{
1618 		.core_note_type = NT_S390_GS_CB,
1619 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1620 		.size = sizeof(__u64),
1621 		.align = sizeof(__u64),
1622 		.regset_get = s390_gs_cb_get,
1623 		.set = s390_gs_cb_set,
1624 	},
1625 	{
1626 		.core_note_type = NT_S390_GS_BC,
1627 		.n = sizeof(struct gs_cb) / sizeof(__u64),
1628 		.size = sizeof(__u64),
1629 		.align = sizeof(__u64),
1630 		.regset_get = s390_gs_bc_get,
1631 		.set = s390_gs_bc_set,
1632 	},
1633 	{
1634 		.core_note_type = NT_S390_RI_CB,
1635 		.n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1636 		.size = sizeof(__u64),
1637 		.align = sizeof(__u64),
1638 		.regset_get = s390_runtime_instr_get,
1639 		.set = s390_runtime_instr_set,
1640 	},
1641 };
1642 
1643 static const struct user_regset_view user_s390_compat_view = {
1644 	.name = "s390",
1645 	.e_machine = EM_S390,
1646 	.regsets = s390_compat_regsets,
1647 	.n = ARRAY_SIZE(s390_compat_regsets)
1648 };
1649 #endif
1650 
1651 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1652 {
1653 #ifdef CONFIG_COMPAT
1654 	if (test_tsk_thread_flag(task, TIF_31BIT))
1655 		return &user_s390_compat_view;
1656 #endif
1657 	return &user_s390_view;
1658 }
1659 
1660 static const char *gpr_names[NUM_GPRS] = {
1661 	"r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1662 	"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1663 };
1664 
1665 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1666 {
1667 	if (offset >= NUM_GPRS)
1668 		return 0;
1669 	return regs->gprs[offset];
1670 }
1671 
1672 int regs_query_register_offset(const char *name)
1673 {
1674 	unsigned long offset;
1675 
1676 	if (!name || *name != 'r')
1677 		return -EINVAL;
1678 	if (kstrtoul(name + 1, 10, &offset))
1679 		return -EINVAL;
1680 	if (offset >= NUM_GPRS)
1681 		return -EINVAL;
1682 	return offset;
1683 }
1684 
1685 const char *regs_query_register_name(unsigned int offset)
1686 {
1687 	if (offset >= NUM_GPRS)
1688 		return NULL;
1689 	return gpr_names[offset];
1690 }
1691 
1692 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1693 {
1694 	unsigned long ksp = kernel_stack_pointer(regs);
1695 
1696 	return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1697 }
1698 
1699 /**
1700  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1701  * @regs:pt_regs which contains kernel stack pointer.
1702  * @n:stack entry number.
1703  *
1704  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1705  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1706  * this returns 0.
1707  */
1708 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1709 {
1710 	unsigned long addr;
1711 
1712 	addr = kernel_stack_pointer(regs) + n * sizeof(long);
1713 	if (!regs_within_kernel_stack(regs, addr))
1714 		return 0;
1715 	return *(unsigned long *)addr;
1716 }
1717