xref: /openbmc/linux/arch/ia64/kernel/ptrace.c (revision 11a163f2)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Kernel support for the ptrace() and syscall tracing interfaces.
4  *
5  * Copyright (C) 1999-2005 Hewlett-Packard Co
6  *	David Mosberger-Tang <davidm@hpl.hp.com>
7  * Copyright (C) 2006 Intel Co
8  *  2006-08-12	- IA64 Native Utrace implementation support added by
9  *	Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
10  *
11  * Derived from the x86 and Alpha versions.
12  */
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/sched/task.h>
16 #include <linux/sched/task_stack.h>
17 #include <linux/mm.h>
18 #include <linux/errno.h>
19 #include <linux/ptrace.h>
20 #include <linux/user.h>
21 #include <linux/security.h>
22 #include <linux/audit.h>
23 #include <linux/signal.h>
24 #include <linux/regset.h>
25 #include <linux/elf.h>
26 #include <linux/tracehook.h>
27 
28 #include <asm/processor.h>
29 #include <asm/ptrace_offsets.h>
30 #include <asm/rse.h>
31 #include <linux/uaccess.h>
32 #include <asm/unwind.h>
33 
34 #include "entry.h"
35 
36 /*
37  * Bits in the PSR that we allow ptrace() to change:
38  *	be, up, ac, mfl, mfh (the user mask; five bits total)
39  *	db (debug breakpoint fault; one bit)
40  *	id (instruction debug fault disable; one bit)
41  *	dd (data debug fault disable; one bit)
42  *	ri (restart instruction; two bits)
43  *	is (instruction set; one bit)
44  */
45 #define IPSR_MASK (IA64_PSR_UM | IA64_PSR_DB | IA64_PSR_IS	\
46 		   | IA64_PSR_ID | IA64_PSR_DD | IA64_PSR_RI)
47 
48 #define MASK(nbits)	((1UL << (nbits)) - 1)	/* mask with NBITS bits set */
49 #define PFM_MASK	MASK(38)
50 
51 #define PTRACE_DEBUG	0
52 
53 #if PTRACE_DEBUG
54 # define dprintk(format...)	printk(format)
55 # define inline
56 #else
57 # define dprintk(format...)
58 #endif
59 
60 /* Return TRUE if PT was created due to kernel-entry via a system-call.  */
61 
62 static inline int
63 in_syscall (struct pt_regs *pt)
64 {
65 	return (long) pt->cr_ifs >= 0;
66 }
67 
68 /*
69  * Collect the NaT bits for r1-r31 from scratch_unat and return a NaT
70  * bitset where bit i is set iff the NaT bit of register i is set.
71  */
72 unsigned long
73 ia64_get_scratch_nat_bits (struct pt_regs *pt, unsigned long scratch_unat)
74 {
75 #	define GET_BITS(first, last, unat)				\
76 	({								\
77 		unsigned long bit = ia64_unat_pos(&pt->r##first);	\
78 		unsigned long nbits = (last - first + 1);		\
79 		unsigned long mask = MASK(nbits) << first;		\
80 		unsigned long dist;					\
81 		if (bit < first)					\
82 			dist = 64 + bit - first;			\
83 		else							\
84 			dist = bit - first;				\
85 		ia64_rotr(unat, dist) & mask;				\
86 	})
87 	unsigned long val;
88 
89 	/*
90 	 * Registers that are stored consecutively in struct pt_regs
91 	 * can be handled in parallel.  If the register order in
92 	 * struct_pt_regs changes, this code MUST be updated.
93 	 */
94 	val  = GET_BITS( 1,  1, scratch_unat);
95 	val |= GET_BITS( 2,  3, scratch_unat);
96 	val |= GET_BITS(12, 13, scratch_unat);
97 	val |= GET_BITS(14, 14, scratch_unat);
98 	val |= GET_BITS(15, 15, scratch_unat);
99 	val |= GET_BITS( 8, 11, scratch_unat);
100 	val |= GET_BITS(16, 31, scratch_unat);
101 	return val;
102 
103 #	undef GET_BITS
104 }
105 
106 /*
107  * Set the NaT bits for the scratch registers according to NAT and
108  * return the resulting unat (assuming the scratch registers are
109  * stored in PT).
110  */
111 unsigned long
112 ia64_put_scratch_nat_bits (struct pt_regs *pt, unsigned long nat)
113 {
114 #	define PUT_BITS(first, last, nat)				\
115 	({								\
116 		unsigned long bit = ia64_unat_pos(&pt->r##first);	\
117 		unsigned long nbits = (last - first + 1);		\
118 		unsigned long mask = MASK(nbits) << first;		\
119 		long dist;						\
120 		if (bit < first)					\
121 			dist = 64 + bit - first;			\
122 		else							\
123 			dist = bit - first;				\
124 		ia64_rotl(nat & mask, dist);				\
125 	})
126 	unsigned long scratch_unat;
127 
128 	/*
129 	 * Registers that are stored consecutively in struct pt_regs
130 	 * can be handled in parallel.  If the register order in
131 	 * struct_pt_regs changes, this code MUST be updated.
132 	 */
133 	scratch_unat  = PUT_BITS( 1,  1, nat);
134 	scratch_unat |= PUT_BITS( 2,  3, nat);
135 	scratch_unat |= PUT_BITS(12, 13, nat);
136 	scratch_unat |= PUT_BITS(14, 14, nat);
137 	scratch_unat |= PUT_BITS(15, 15, nat);
138 	scratch_unat |= PUT_BITS( 8, 11, nat);
139 	scratch_unat |= PUT_BITS(16, 31, nat);
140 
141 	return scratch_unat;
142 
143 #	undef PUT_BITS
144 }
145 
146 #define IA64_MLX_TEMPLATE	0x2
147 #define IA64_MOVL_OPCODE	6
148 
149 void
150 ia64_increment_ip (struct pt_regs *regs)
151 {
152 	unsigned long w0, ri = ia64_psr(regs)->ri + 1;
153 
154 	if (ri > 2) {
155 		ri = 0;
156 		regs->cr_iip += 16;
157 	} else if (ri == 2) {
158 		get_user(w0, (char __user *) regs->cr_iip + 0);
159 		if (((w0 >> 1) & 0xf) == IA64_MLX_TEMPLATE) {
160 			/*
161 			 * rfi'ing to slot 2 of an MLX bundle causes
162 			 * an illegal operation fault.  We don't want
163 			 * that to happen...
164 			 */
165 			ri = 0;
166 			regs->cr_iip += 16;
167 		}
168 	}
169 	ia64_psr(regs)->ri = ri;
170 }
171 
172 void
173 ia64_decrement_ip (struct pt_regs *regs)
174 {
175 	unsigned long w0, ri = ia64_psr(regs)->ri - 1;
176 
177 	if (ia64_psr(regs)->ri == 0) {
178 		regs->cr_iip -= 16;
179 		ri = 2;
180 		get_user(w0, (char __user *) regs->cr_iip + 0);
181 		if (((w0 >> 1) & 0xf) == IA64_MLX_TEMPLATE) {
182 			/*
183 			 * rfi'ing to slot 2 of an MLX bundle causes
184 			 * an illegal operation fault.  We don't want
185 			 * that to happen...
186 			 */
187 			ri = 1;
188 		}
189 	}
190 	ia64_psr(regs)->ri = ri;
191 }
192 
193 /*
194  * This routine is used to read an rnat bits that are stored on the
195  * kernel backing store.  Since, in general, the alignment of the user
196  * and kernel are different, this is not completely trivial.  In
197  * essence, we need to construct the user RNAT based on up to two
198  * kernel RNAT values and/or the RNAT value saved in the child's
199  * pt_regs.
200  *
201  * user rbs
202  *
203  * +--------+ <-- lowest address
204  * | slot62 |
205  * +--------+
206  * |  rnat  | 0x....1f8
207  * +--------+
208  * | slot00 | \
209  * +--------+ |
210  * | slot01 | > child_regs->ar_rnat
211  * +--------+ |
212  * | slot02 | /				kernel rbs
213  * +--------+				+--------+
214  *	    <- child_regs->ar_bspstore	| slot61 | <-- krbs
215  * +- - - - +				+--------+
216  *					| slot62 |
217  * +- - - - +				+--------+
218  *					|  rnat	 |
219  * +- - - - +				+--------+
220  *   vrnat				| slot00 |
221  * +- - - - +				+--------+
222  *					=	 =
223  *					+--------+
224  *					| slot00 | \
225  *					+--------+ |
226  *					| slot01 | > child_stack->ar_rnat
227  *					+--------+ |
228  *					| slot02 | /
229  *					+--------+
230  *						  <--- child_stack->ar_bspstore
231  *
232  * The way to think of this code is as follows: bit 0 in the user rnat
233  * corresponds to some bit N (0 <= N <= 62) in one of the kernel rnat
234  * value.  The kernel rnat value holding this bit is stored in
235  * variable rnat0.  rnat1 is loaded with the kernel rnat value that
236  * form the upper bits of the user rnat value.
237  *
238  * Boundary cases:
239  *
240  * o when reading the rnat "below" the first rnat slot on the kernel
241  *   backing store, rnat0/rnat1 are set to 0 and the low order bits are
242  *   merged in from pt->ar_rnat.
243  *
244  * o when reading the rnat "above" the last rnat slot on the kernel
245  *   backing store, rnat0/rnat1 gets its value from sw->ar_rnat.
246  */
247 static unsigned long
248 get_rnat (struct task_struct *task, struct switch_stack *sw,
249 	  unsigned long *krbs, unsigned long *urnat_addr,
250 	  unsigned long *urbs_end)
251 {
252 	unsigned long rnat0 = 0, rnat1 = 0, urnat = 0, *slot0_kaddr;
253 	unsigned long umask = 0, mask, m;
254 	unsigned long *kbsp, *ubspstore, *rnat0_kaddr, *rnat1_kaddr, shift;
255 	long num_regs, nbits;
256 	struct pt_regs *pt;
257 
258 	pt = task_pt_regs(task);
259 	kbsp = (unsigned long *) sw->ar_bspstore;
260 	ubspstore = (unsigned long *) pt->ar_bspstore;
261 
262 	if (urbs_end < urnat_addr)
263 		nbits = ia64_rse_num_regs(urnat_addr - 63, urbs_end);
264 	else
265 		nbits = 63;
266 	mask = MASK(nbits);
267 	/*
268 	 * First, figure out which bit number slot 0 in user-land maps
269 	 * to in the kernel rnat.  Do this by figuring out how many
270 	 * register slots we're beyond the user's backingstore and
271 	 * then computing the equivalent address in kernel space.
272 	 */
273 	num_regs = ia64_rse_num_regs(ubspstore, urnat_addr + 1);
274 	slot0_kaddr = ia64_rse_skip_regs(krbs, num_regs);
275 	shift = ia64_rse_slot_num(slot0_kaddr);
276 	rnat1_kaddr = ia64_rse_rnat_addr(slot0_kaddr);
277 	rnat0_kaddr = rnat1_kaddr - 64;
278 
279 	if (ubspstore + 63 > urnat_addr) {
280 		/* some bits need to be merged in from pt->ar_rnat */
281 		umask = MASK(ia64_rse_slot_num(ubspstore)) & mask;
282 		urnat = (pt->ar_rnat & umask);
283 		mask &= ~umask;
284 		if (!mask)
285 			return urnat;
286 	}
287 
288 	m = mask << shift;
289 	if (rnat0_kaddr >= kbsp)
290 		rnat0 = sw->ar_rnat;
291 	else if (rnat0_kaddr > krbs)
292 		rnat0 = *rnat0_kaddr;
293 	urnat |= (rnat0 & m) >> shift;
294 
295 	m = mask >> (63 - shift);
296 	if (rnat1_kaddr >= kbsp)
297 		rnat1 = sw->ar_rnat;
298 	else if (rnat1_kaddr > krbs)
299 		rnat1 = *rnat1_kaddr;
300 	urnat |= (rnat1 & m) << (63 - shift);
301 	return urnat;
302 }
303 
304 /*
305  * The reverse of get_rnat.
306  */
307 static void
308 put_rnat (struct task_struct *task, struct switch_stack *sw,
309 	  unsigned long *krbs, unsigned long *urnat_addr, unsigned long urnat,
310 	  unsigned long *urbs_end)
311 {
312 	unsigned long rnat0 = 0, rnat1 = 0, *slot0_kaddr, umask = 0, mask, m;
313 	unsigned long *kbsp, *ubspstore, *rnat0_kaddr, *rnat1_kaddr, shift;
314 	long num_regs, nbits;
315 	struct pt_regs *pt;
316 	unsigned long cfm, *urbs_kargs;
317 
318 	pt = task_pt_regs(task);
319 	kbsp = (unsigned long *) sw->ar_bspstore;
320 	ubspstore = (unsigned long *) pt->ar_bspstore;
321 
322 	urbs_kargs = urbs_end;
323 	if (in_syscall(pt)) {
324 		/*
325 		 * If entered via syscall, don't allow user to set rnat bits
326 		 * for syscall args.
327 		 */
328 		cfm = pt->cr_ifs;
329 		urbs_kargs = ia64_rse_skip_regs(urbs_end, -(cfm & 0x7f));
330 	}
331 
332 	if (urbs_kargs >= urnat_addr)
333 		nbits = 63;
334 	else {
335 		if ((urnat_addr - 63) >= urbs_kargs)
336 			return;
337 		nbits = ia64_rse_num_regs(urnat_addr - 63, urbs_kargs);
338 	}
339 	mask = MASK(nbits);
340 
341 	/*
342 	 * First, figure out which bit number slot 0 in user-land maps
343 	 * to in the kernel rnat.  Do this by figuring out how many
344 	 * register slots we're beyond the user's backingstore and
345 	 * then computing the equivalent address in kernel space.
346 	 */
347 	num_regs = ia64_rse_num_regs(ubspstore, urnat_addr + 1);
348 	slot0_kaddr = ia64_rse_skip_regs(krbs, num_regs);
349 	shift = ia64_rse_slot_num(slot0_kaddr);
350 	rnat1_kaddr = ia64_rse_rnat_addr(slot0_kaddr);
351 	rnat0_kaddr = rnat1_kaddr - 64;
352 
353 	if (ubspstore + 63 > urnat_addr) {
354 		/* some bits need to be place in pt->ar_rnat: */
355 		umask = MASK(ia64_rse_slot_num(ubspstore)) & mask;
356 		pt->ar_rnat = (pt->ar_rnat & ~umask) | (urnat & umask);
357 		mask &= ~umask;
358 		if (!mask)
359 			return;
360 	}
361 	/*
362 	 * Note: Section 11.1 of the EAS guarantees that bit 63 of an
363 	 * rnat slot is ignored. so we don't have to clear it here.
364 	 */
365 	rnat0 = (urnat << shift);
366 	m = mask << shift;
367 	if (rnat0_kaddr >= kbsp)
368 		sw->ar_rnat = (sw->ar_rnat & ~m) | (rnat0 & m);
369 	else if (rnat0_kaddr > krbs)
370 		*rnat0_kaddr = ((*rnat0_kaddr & ~m) | (rnat0 & m));
371 
372 	rnat1 = (urnat >> (63 - shift));
373 	m = mask >> (63 - shift);
374 	if (rnat1_kaddr >= kbsp)
375 		sw->ar_rnat = (sw->ar_rnat & ~m) | (rnat1 & m);
376 	else if (rnat1_kaddr > krbs)
377 		*rnat1_kaddr = ((*rnat1_kaddr & ~m) | (rnat1 & m));
378 }
379 
380 static inline int
381 on_kernel_rbs (unsigned long addr, unsigned long bspstore,
382 	       unsigned long urbs_end)
383 {
384 	unsigned long *rnat_addr = ia64_rse_rnat_addr((unsigned long *)
385 						      urbs_end);
386 	return (addr >= bspstore && addr <= (unsigned long) rnat_addr);
387 }
388 
389 /*
390  * Read a word from the user-level backing store of task CHILD.  ADDR
391  * is the user-level address to read the word from, VAL a pointer to
392  * the return value, and USER_BSP gives the end of the user-level
393  * backing store (i.e., it's the address that would be in ar.bsp after
394  * the user executed a "cover" instruction).
395  *
396  * This routine takes care of accessing the kernel register backing
397  * store for those registers that got spilled there.  It also takes
398  * care of calculating the appropriate RNaT collection words.
399  */
400 long
401 ia64_peek (struct task_struct *child, struct switch_stack *child_stack,
402 	   unsigned long user_rbs_end, unsigned long addr, long *val)
403 {
404 	unsigned long *bspstore, *krbs, regnum, *laddr, *urbs_end, *rnat_addr;
405 	struct pt_regs *child_regs;
406 	size_t copied;
407 	long ret;
408 
409 	urbs_end = (long *) user_rbs_end;
410 	laddr = (unsigned long *) addr;
411 	child_regs = task_pt_regs(child);
412 	bspstore = (unsigned long *) child_regs->ar_bspstore;
413 	krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
414 	if (on_kernel_rbs(addr, (unsigned long) bspstore,
415 			  (unsigned long) urbs_end))
416 	{
417 		/*
418 		 * Attempt to read the RBS in an area that's actually
419 		 * on the kernel RBS => read the corresponding bits in
420 		 * the kernel RBS.
421 		 */
422 		rnat_addr = ia64_rse_rnat_addr(laddr);
423 		ret = get_rnat(child, child_stack, krbs, rnat_addr, urbs_end);
424 
425 		if (laddr == rnat_addr) {
426 			/* return NaT collection word itself */
427 			*val = ret;
428 			return 0;
429 		}
430 
431 		if (((1UL << ia64_rse_slot_num(laddr)) & ret) != 0) {
432 			/*
433 			 * It is implementation dependent whether the
434 			 * data portion of a NaT value gets saved on a
435 			 * st8.spill or RSE spill (e.g., see EAS 2.6,
436 			 * 4.4.4.6 Register Spill and Fill).  To get
437 			 * consistent behavior across all possible
438 			 * IA-64 implementations, we return zero in
439 			 * this case.
440 			 */
441 			*val = 0;
442 			return 0;
443 		}
444 
445 		if (laddr < urbs_end) {
446 			/*
447 			 * The desired word is on the kernel RBS and
448 			 * is not a NaT.
449 			 */
450 			regnum = ia64_rse_num_regs(bspstore, laddr);
451 			*val = *ia64_rse_skip_regs(krbs, regnum);
452 			return 0;
453 		}
454 	}
455 	copied = access_process_vm(child, addr, &ret, sizeof(ret), FOLL_FORCE);
456 	if (copied != sizeof(ret))
457 		return -EIO;
458 	*val = ret;
459 	return 0;
460 }
461 
462 long
463 ia64_poke (struct task_struct *child, struct switch_stack *child_stack,
464 	   unsigned long user_rbs_end, unsigned long addr, long val)
465 {
466 	unsigned long *bspstore, *krbs, regnum, *laddr;
467 	unsigned long *urbs_end = (long *) user_rbs_end;
468 	struct pt_regs *child_regs;
469 
470 	laddr = (unsigned long *) addr;
471 	child_regs = task_pt_regs(child);
472 	bspstore = (unsigned long *) child_regs->ar_bspstore;
473 	krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
474 	if (on_kernel_rbs(addr, (unsigned long) bspstore,
475 			  (unsigned long) urbs_end))
476 	{
477 		/*
478 		 * Attempt to write the RBS in an area that's actually
479 		 * on the kernel RBS => write the corresponding bits
480 		 * in the kernel RBS.
481 		 */
482 		if (ia64_rse_is_rnat_slot(laddr))
483 			put_rnat(child, child_stack, krbs, laddr, val,
484 				 urbs_end);
485 		else {
486 			if (laddr < urbs_end) {
487 				regnum = ia64_rse_num_regs(bspstore, laddr);
488 				*ia64_rse_skip_regs(krbs, regnum) = val;
489 			}
490 		}
491 	} else if (access_process_vm(child, addr, &val, sizeof(val),
492 				FOLL_FORCE | FOLL_WRITE)
493 		   != sizeof(val))
494 		return -EIO;
495 	return 0;
496 }
497 
498 /*
499  * Calculate the address of the end of the user-level register backing
500  * store.  This is the address that would have been stored in ar.bsp
501  * if the user had executed a "cover" instruction right before
502  * entering the kernel.  If CFMP is not NULL, it is used to return the
503  * "current frame mask" that was active at the time the kernel was
504  * entered.
505  */
506 unsigned long
507 ia64_get_user_rbs_end (struct task_struct *child, struct pt_regs *pt,
508 		       unsigned long *cfmp)
509 {
510 	unsigned long *krbs, *bspstore, cfm = pt->cr_ifs;
511 	long ndirty;
512 
513 	krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
514 	bspstore = (unsigned long *) pt->ar_bspstore;
515 	ndirty = ia64_rse_num_regs(krbs, krbs + (pt->loadrs >> 19));
516 
517 	if (in_syscall(pt))
518 		ndirty += (cfm & 0x7f);
519 	else
520 		cfm &= ~(1UL << 63);	/* clear valid bit */
521 
522 	if (cfmp)
523 		*cfmp = cfm;
524 	return (unsigned long) ia64_rse_skip_regs(bspstore, ndirty);
525 }
526 
527 /*
528  * Synchronize (i.e, write) the RSE backing store living in kernel
529  * space to the VM of the CHILD task.  SW and PT are the pointers to
530  * the switch_stack and pt_regs structures, respectively.
531  * USER_RBS_END is the user-level address at which the backing store
532  * ends.
533  */
534 long
535 ia64_sync_user_rbs (struct task_struct *child, struct switch_stack *sw,
536 		    unsigned long user_rbs_start, unsigned long user_rbs_end)
537 {
538 	unsigned long addr, val;
539 	long ret;
540 
541 	/* now copy word for word from kernel rbs to user rbs: */
542 	for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) {
543 		ret = ia64_peek(child, sw, user_rbs_end, addr, &val);
544 		if (ret < 0)
545 			return ret;
546 		if (access_process_vm(child, addr, &val, sizeof(val),
547 				FOLL_FORCE | FOLL_WRITE)
548 		    != sizeof(val))
549 			return -EIO;
550 	}
551 	return 0;
552 }
553 
554 static long
555 ia64_sync_kernel_rbs (struct task_struct *child, struct switch_stack *sw,
556 		unsigned long user_rbs_start, unsigned long user_rbs_end)
557 {
558 	unsigned long addr, val;
559 	long ret;
560 
561 	/* now copy word for word from user rbs to kernel rbs: */
562 	for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) {
563 		if (access_process_vm(child, addr, &val, sizeof(val),
564 				FOLL_FORCE)
565 				!= sizeof(val))
566 			return -EIO;
567 
568 		ret = ia64_poke(child, sw, user_rbs_end, addr, val);
569 		if (ret < 0)
570 			return ret;
571 	}
572 	return 0;
573 }
574 
575 typedef long (*syncfunc_t)(struct task_struct *, struct switch_stack *,
576 			    unsigned long, unsigned long);
577 
578 static void do_sync_rbs(struct unw_frame_info *info, void *arg)
579 {
580 	struct pt_regs *pt;
581 	unsigned long urbs_end;
582 	syncfunc_t fn = arg;
583 
584 	if (unw_unwind_to_user(info) < 0)
585 		return;
586 	pt = task_pt_regs(info->task);
587 	urbs_end = ia64_get_user_rbs_end(info->task, pt, NULL);
588 
589 	fn(info->task, info->sw, pt->ar_bspstore, urbs_end);
590 }
591 
592 /*
593  * when a thread is stopped (ptraced), debugger might change thread's user
594  * stack (change memory directly), and we must avoid the RSE stored in kernel
595  * to override user stack (user space's RSE is newer than kernel's in the
596  * case). To workaround the issue, we copy kernel RSE to user RSE before the
597  * task is stopped, so user RSE has updated data.  we then copy user RSE to
598  * kernel after the task is resummed from traced stop and kernel will use the
599  * newer RSE to return to user. TIF_RESTORE_RSE is the flag to indicate we need
600  * synchronize user RSE to kernel.
601  */
602 void ia64_ptrace_stop(void)
603 {
604 	if (test_and_set_tsk_thread_flag(current, TIF_RESTORE_RSE))
605 		return;
606 	set_notify_resume(current);
607 	unw_init_running(do_sync_rbs, ia64_sync_user_rbs);
608 }
609 
610 /*
611  * This is called to read back the register backing store.
612  */
613 void ia64_sync_krbs(void)
614 {
615 	clear_tsk_thread_flag(current, TIF_RESTORE_RSE);
616 
617 	unw_init_running(do_sync_rbs, ia64_sync_kernel_rbs);
618 }
619 
620 /*
621  * After PTRACE_ATTACH, a thread's register backing store area in user
622  * space is assumed to contain correct data whenever the thread is
623  * stopped.  arch_ptrace_stop takes care of this on tracing stops.
624  * But if the child was already stopped for job control when we attach
625  * to it, then it might not ever get into ptrace_stop by the time we
626  * want to examine the user memory containing the RBS.
627  */
628 void
629 ptrace_attach_sync_user_rbs (struct task_struct *child)
630 {
631 	int stopped = 0;
632 	struct unw_frame_info info;
633 
634 	/*
635 	 * If the child is in TASK_STOPPED, we need to change that to
636 	 * TASK_TRACED momentarily while we operate on it.  This ensures
637 	 * that the child won't be woken up and return to user mode while
638 	 * we are doing the sync.  (It can only be woken up for SIGKILL.)
639 	 */
640 
641 	read_lock(&tasklist_lock);
642 	if (child->sighand) {
643 		spin_lock_irq(&child->sighand->siglock);
644 		if (child->state == TASK_STOPPED &&
645 		    !test_and_set_tsk_thread_flag(child, TIF_RESTORE_RSE)) {
646 			set_notify_resume(child);
647 
648 			child->state = TASK_TRACED;
649 			stopped = 1;
650 		}
651 		spin_unlock_irq(&child->sighand->siglock);
652 	}
653 	read_unlock(&tasklist_lock);
654 
655 	if (!stopped)
656 		return;
657 
658 	unw_init_from_blocked_task(&info, child);
659 	do_sync_rbs(&info, ia64_sync_user_rbs);
660 
661 	/*
662 	 * Now move the child back into TASK_STOPPED if it should be in a
663 	 * job control stop, so that SIGCONT can be used to wake it up.
664 	 */
665 	read_lock(&tasklist_lock);
666 	if (child->sighand) {
667 		spin_lock_irq(&child->sighand->siglock);
668 		if (child->state == TASK_TRACED &&
669 		    (child->signal->flags & SIGNAL_STOP_STOPPED)) {
670 			child->state = TASK_STOPPED;
671 		}
672 		spin_unlock_irq(&child->sighand->siglock);
673 	}
674 	read_unlock(&tasklist_lock);
675 }
676 
677 /*
678  * Write f32-f127 back to task->thread.fph if it has been modified.
679  */
680 inline void
681 ia64_flush_fph (struct task_struct *task)
682 {
683 	struct ia64_psr *psr = ia64_psr(task_pt_regs(task));
684 
685 	/*
686 	 * Prevent migrating this task while
687 	 * we're fiddling with the FPU state
688 	 */
689 	preempt_disable();
690 	if (ia64_is_local_fpu_owner(task) && psr->mfh) {
691 		psr->mfh = 0;
692 		task->thread.flags |= IA64_THREAD_FPH_VALID;
693 		ia64_save_fpu(&task->thread.fph[0]);
694 	}
695 	preempt_enable();
696 }
697 
698 /*
699  * Sync the fph state of the task so that it can be manipulated
700  * through thread.fph.  If necessary, f32-f127 are written back to
701  * thread.fph or, if the fph state hasn't been used before, thread.fph
702  * is cleared to zeroes.  Also, access to f32-f127 is disabled to
703  * ensure that the task picks up the state from thread.fph when it
704  * executes again.
705  */
706 void
707 ia64_sync_fph (struct task_struct *task)
708 {
709 	struct ia64_psr *psr = ia64_psr(task_pt_regs(task));
710 
711 	ia64_flush_fph(task);
712 	if (!(task->thread.flags & IA64_THREAD_FPH_VALID)) {
713 		task->thread.flags |= IA64_THREAD_FPH_VALID;
714 		memset(&task->thread.fph, 0, sizeof(task->thread.fph));
715 	}
716 	ia64_drop_fpu(task);
717 	psr->dfh = 1;
718 }
719 
720 /*
721  * Change the machine-state of CHILD such that it will return via the normal
722  * kernel exit-path, rather than the syscall-exit path.
723  */
724 static void
725 convert_to_non_syscall (struct task_struct *child, struct pt_regs  *pt,
726 			unsigned long cfm)
727 {
728 	struct unw_frame_info info, prev_info;
729 	unsigned long ip, sp, pr;
730 
731 	unw_init_from_blocked_task(&info, child);
732 	while (1) {
733 		prev_info = info;
734 		if (unw_unwind(&info) < 0)
735 			return;
736 
737 		unw_get_sp(&info, &sp);
738 		if ((long)((unsigned long)child + IA64_STK_OFFSET - sp)
739 		    < IA64_PT_REGS_SIZE) {
740 			dprintk("ptrace.%s: ran off the top of the kernel "
741 				"stack\n", __func__);
742 			return;
743 		}
744 		if (unw_get_pr (&prev_info, &pr) < 0) {
745 			unw_get_rp(&prev_info, &ip);
746 			dprintk("ptrace.%s: failed to read "
747 				"predicate register (ip=0x%lx)\n",
748 				__func__, ip);
749 			return;
750 		}
751 		if (unw_is_intr_frame(&info)
752 		    && (pr & (1UL << PRED_USER_STACK)))
753 			break;
754 	}
755 
756 	/*
757 	 * Note: at the time of this call, the target task is blocked
758 	 * in notify_resume_user() and by clearling PRED_LEAVE_SYSCALL
759 	 * (aka, "pLvSys") we redirect execution from
760 	 * .work_pending_syscall_end to .work_processed_kernel.
761 	 */
762 	unw_get_pr(&prev_info, &pr);
763 	pr &= ~((1UL << PRED_SYSCALL) | (1UL << PRED_LEAVE_SYSCALL));
764 	pr |=  (1UL << PRED_NON_SYSCALL);
765 	unw_set_pr(&prev_info, pr);
766 
767 	pt->cr_ifs = (1UL << 63) | cfm;
768 	/*
769 	 * Clear the memory that is NOT written on syscall-entry to
770 	 * ensure we do not leak kernel-state to user when execution
771 	 * resumes.
772 	 */
773 	pt->r2 = 0;
774 	pt->r3 = 0;
775 	pt->r14 = 0;
776 	memset(&pt->r16, 0, 16*8);	/* clear r16-r31 */
777 	memset(&pt->f6, 0, 6*16);	/* clear f6-f11 */
778 	pt->b7 = 0;
779 	pt->ar_ccv = 0;
780 	pt->ar_csd = 0;
781 	pt->ar_ssd = 0;
782 }
783 
784 static int
785 access_nat_bits (struct task_struct *child, struct pt_regs *pt,
786 		 struct unw_frame_info *info,
787 		 unsigned long *data, int write_access)
788 {
789 	unsigned long regnum, nat_bits, scratch_unat, dummy = 0;
790 	char nat = 0;
791 
792 	if (write_access) {
793 		nat_bits = *data;
794 		scratch_unat = ia64_put_scratch_nat_bits(pt, nat_bits);
795 		if (unw_set_ar(info, UNW_AR_UNAT, scratch_unat) < 0) {
796 			dprintk("ptrace: failed to set ar.unat\n");
797 			return -1;
798 		}
799 		for (regnum = 4; regnum <= 7; ++regnum) {
800 			unw_get_gr(info, regnum, &dummy, &nat);
801 			unw_set_gr(info, regnum, dummy,
802 				   (nat_bits >> regnum) & 1);
803 		}
804 	} else {
805 		if (unw_get_ar(info, UNW_AR_UNAT, &scratch_unat) < 0) {
806 			dprintk("ptrace: failed to read ar.unat\n");
807 			return -1;
808 		}
809 		nat_bits = ia64_get_scratch_nat_bits(pt, scratch_unat);
810 		for (regnum = 4; regnum <= 7; ++regnum) {
811 			unw_get_gr(info, regnum, &dummy, &nat);
812 			nat_bits |= (nat != 0) << regnum;
813 		}
814 		*data = nat_bits;
815 	}
816 	return 0;
817 }
818 
819 static int
820 access_uarea (struct task_struct *child, unsigned long addr,
821 	      unsigned long *data, int write_access);
822 
823 static long
824 ptrace_getregs (struct task_struct *child, struct pt_all_user_regs __user *ppr)
825 {
826 	unsigned long psr, ec, lc, rnat, bsp, cfm, nat_bits, val;
827 	struct unw_frame_info info;
828 	struct ia64_fpreg fpval;
829 	struct switch_stack *sw;
830 	struct pt_regs *pt;
831 	long ret, retval = 0;
832 	char nat = 0;
833 	int i;
834 
835 	if (!access_ok(ppr, sizeof(struct pt_all_user_regs)))
836 		return -EIO;
837 
838 	pt = task_pt_regs(child);
839 	sw = (struct switch_stack *) (child->thread.ksp + 16);
840 	unw_init_from_blocked_task(&info, child);
841 	if (unw_unwind_to_user(&info) < 0) {
842 		return -EIO;
843 	}
844 
845 	if (((unsigned long) ppr & 0x7) != 0) {
846 		dprintk("ptrace:unaligned register address %p\n", ppr);
847 		return -EIO;
848 	}
849 
850 	if (access_uarea(child, PT_CR_IPSR, &psr, 0) < 0
851 	    || access_uarea(child, PT_AR_EC, &ec, 0) < 0
852 	    || access_uarea(child, PT_AR_LC, &lc, 0) < 0
853 	    || access_uarea(child, PT_AR_RNAT, &rnat, 0) < 0
854 	    || access_uarea(child, PT_AR_BSP, &bsp, 0) < 0
855 	    || access_uarea(child, PT_CFM, &cfm, 0)
856 	    || access_uarea(child, PT_NAT_BITS, &nat_bits, 0))
857 		return -EIO;
858 
859 	/* control regs */
860 
861 	retval |= __put_user(pt->cr_iip, &ppr->cr_iip);
862 	retval |= __put_user(psr, &ppr->cr_ipsr);
863 
864 	/* app regs */
865 
866 	retval |= __put_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
867 	retval |= __put_user(pt->ar_rsc, &ppr->ar[PT_AUR_RSC]);
868 	retval |= __put_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
869 	retval |= __put_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
870 	retval |= __put_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
871 	retval |= __put_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);
872 
873 	retval |= __put_user(ec, &ppr->ar[PT_AUR_EC]);
874 	retval |= __put_user(lc, &ppr->ar[PT_AUR_LC]);
875 	retval |= __put_user(rnat, &ppr->ar[PT_AUR_RNAT]);
876 	retval |= __put_user(bsp, &ppr->ar[PT_AUR_BSP]);
877 	retval |= __put_user(cfm, &ppr->cfm);
878 
879 	/* gr1-gr3 */
880 
881 	retval |= __copy_to_user(&ppr->gr[1], &pt->r1, sizeof(long));
882 	retval |= __copy_to_user(&ppr->gr[2], &pt->r2, sizeof(long) *2);
883 
884 	/* gr4-gr7 */
885 
886 	for (i = 4; i < 8; i++) {
887 		if (unw_access_gr(&info, i, &val, &nat, 0) < 0)
888 			return -EIO;
889 		retval |= __put_user(val, &ppr->gr[i]);
890 	}
891 
892 	/* gr8-gr11 */
893 
894 	retval |= __copy_to_user(&ppr->gr[8], &pt->r8, sizeof(long) * 4);
895 
896 	/* gr12-gr15 */
897 
898 	retval |= __copy_to_user(&ppr->gr[12], &pt->r12, sizeof(long) * 2);
899 	retval |= __copy_to_user(&ppr->gr[14], &pt->r14, sizeof(long));
900 	retval |= __copy_to_user(&ppr->gr[15], &pt->r15, sizeof(long));
901 
902 	/* gr16-gr31 */
903 
904 	retval |= __copy_to_user(&ppr->gr[16], &pt->r16, sizeof(long) * 16);
905 
906 	/* b0 */
907 
908 	retval |= __put_user(pt->b0, &ppr->br[0]);
909 
910 	/* b1-b5 */
911 
912 	for (i = 1; i < 6; i++) {
913 		if (unw_access_br(&info, i, &val, 0) < 0)
914 			return -EIO;
915 		__put_user(val, &ppr->br[i]);
916 	}
917 
918 	/* b6-b7 */
919 
920 	retval |= __put_user(pt->b6, &ppr->br[6]);
921 	retval |= __put_user(pt->b7, &ppr->br[7]);
922 
923 	/* fr2-fr5 */
924 
925 	for (i = 2; i < 6; i++) {
926 		if (unw_get_fr(&info, i, &fpval) < 0)
927 			return -EIO;
928 		retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
929 	}
930 
931 	/* fr6-fr11 */
932 
933 	retval |= __copy_to_user(&ppr->fr[6], &pt->f6,
934 				 sizeof(struct ia64_fpreg) * 6);
935 
936 	/* fp scratch regs(12-15) */
937 
938 	retval |= __copy_to_user(&ppr->fr[12], &sw->f12,
939 				 sizeof(struct ia64_fpreg) * 4);
940 
941 	/* fr16-fr31 */
942 
943 	for (i = 16; i < 32; i++) {
944 		if (unw_get_fr(&info, i, &fpval) < 0)
945 			return -EIO;
946 		retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
947 	}
948 
949 	/* fph */
950 
951 	ia64_flush_fph(child);
952 	retval |= __copy_to_user(&ppr->fr[32], &child->thread.fph,
953 				 sizeof(ppr->fr[32]) * 96);
954 
955 	/*  preds */
956 
957 	retval |= __put_user(pt->pr, &ppr->pr);
958 
959 	/* nat bits */
960 
961 	retval |= __put_user(nat_bits, &ppr->nat);
962 
963 	ret = retval ? -EIO : 0;
964 	return ret;
965 }
966 
967 static long
968 ptrace_setregs (struct task_struct *child, struct pt_all_user_regs __user *ppr)
969 {
970 	unsigned long psr, rsc, ec, lc, rnat, bsp, cfm, nat_bits, val = 0;
971 	struct unw_frame_info info;
972 	struct switch_stack *sw;
973 	struct ia64_fpreg fpval;
974 	struct pt_regs *pt;
975 	long ret, retval = 0;
976 	int i;
977 
978 	memset(&fpval, 0, sizeof(fpval));
979 
980 	if (!access_ok(ppr, sizeof(struct pt_all_user_regs)))
981 		return -EIO;
982 
983 	pt = task_pt_regs(child);
984 	sw = (struct switch_stack *) (child->thread.ksp + 16);
985 	unw_init_from_blocked_task(&info, child);
986 	if (unw_unwind_to_user(&info) < 0) {
987 		return -EIO;
988 	}
989 
990 	if (((unsigned long) ppr & 0x7) != 0) {
991 		dprintk("ptrace:unaligned register address %p\n", ppr);
992 		return -EIO;
993 	}
994 
995 	/* control regs */
996 
997 	retval |= __get_user(pt->cr_iip, &ppr->cr_iip);
998 	retval |= __get_user(psr, &ppr->cr_ipsr);
999 
1000 	/* app regs */
1001 
1002 	retval |= __get_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
1003 	retval |= __get_user(rsc, &ppr->ar[PT_AUR_RSC]);
1004 	retval |= __get_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
1005 	retval |= __get_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
1006 	retval |= __get_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
1007 	retval |= __get_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);
1008 
1009 	retval |= __get_user(ec, &ppr->ar[PT_AUR_EC]);
1010 	retval |= __get_user(lc, &ppr->ar[PT_AUR_LC]);
1011 	retval |= __get_user(rnat, &ppr->ar[PT_AUR_RNAT]);
1012 	retval |= __get_user(bsp, &ppr->ar[PT_AUR_BSP]);
1013 	retval |= __get_user(cfm, &ppr->cfm);
1014 
1015 	/* gr1-gr3 */
1016 
1017 	retval |= __copy_from_user(&pt->r1, &ppr->gr[1], sizeof(long));
1018 	retval |= __copy_from_user(&pt->r2, &ppr->gr[2], sizeof(long) * 2);
1019 
1020 	/* gr4-gr7 */
1021 
1022 	for (i = 4; i < 8; i++) {
1023 		retval |= __get_user(val, &ppr->gr[i]);
1024 		/* NaT bit will be set via PT_NAT_BITS: */
1025 		if (unw_set_gr(&info, i, val, 0) < 0)
1026 			return -EIO;
1027 	}
1028 
1029 	/* gr8-gr11 */
1030 
1031 	retval |= __copy_from_user(&pt->r8, &ppr->gr[8], sizeof(long) * 4);
1032 
1033 	/* gr12-gr15 */
1034 
1035 	retval |= __copy_from_user(&pt->r12, &ppr->gr[12], sizeof(long) * 2);
1036 	retval |= __copy_from_user(&pt->r14, &ppr->gr[14], sizeof(long));
1037 	retval |= __copy_from_user(&pt->r15, &ppr->gr[15], sizeof(long));
1038 
1039 	/* gr16-gr31 */
1040 
1041 	retval |= __copy_from_user(&pt->r16, &ppr->gr[16], sizeof(long) * 16);
1042 
1043 	/* b0 */
1044 
1045 	retval |= __get_user(pt->b0, &ppr->br[0]);
1046 
1047 	/* b1-b5 */
1048 
1049 	for (i = 1; i < 6; i++) {
1050 		retval |= __get_user(val, &ppr->br[i]);
1051 		unw_set_br(&info, i, val);
1052 	}
1053 
1054 	/* b6-b7 */
1055 
1056 	retval |= __get_user(pt->b6, &ppr->br[6]);
1057 	retval |= __get_user(pt->b7, &ppr->br[7]);
1058 
1059 	/* fr2-fr5 */
1060 
1061 	for (i = 2; i < 6; i++) {
1062 		retval |= __copy_from_user(&fpval, &ppr->fr[i], sizeof(fpval));
1063 		if (unw_set_fr(&info, i, fpval) < 0)
1064 			return -EIO;
1065 	}
1066 
1067 	/* fr6-fr11 */
1068 
1069 	retval |= __copy_from_user(&pt->f6, &ppr->fr[6],
1070 				   sizeof(ppr->fr[6]) * 6);
1071 
1072 	/* fp scratch regs(12-15) */
1073 
1074 	retval |= __copy_from_user(&sw->f12, &ppr->fr[12],
1075 				   sizeof(ppr->fr[12]) * 4);
1076 
1077 	/* fr16-fr31 */
1078 
1079 	for (i = 16; i < 32; i++) {
1080 		retval |= __copy_from_user(&fpval, &ppr->fr[i],
1081 					   sizeof(fpval));
1082 		if (unw_set_fr(&info, i, fpval) < 0)
1083 			return -EIO;
1084 	}
1085 
1086 	/* fph */
1087 
1088 	ia64_sync_fph(child);
1089 	retval |= __copy_from_user(&child->thread.fph, &ppr->fr[32],
1090 				   sizeof(ppr->fr[32]) * 96);
1091 
1092 	/* preds */
1093 
1094 	retval |= __get_user(pt->pr, &ppr->pr);
1095 
1096 	/* nat bits */
1097 
1098 	retval |= __get_user(nat_bits, &ppr->nat);
1099 
1100 	retval |= access_uarea(child, PT_CR_IPSR, &psr, 1);
1101 	retval |= access_uarea(child, PT_AR_RSC, &rsc, 1);
1102 	retval |= access_uarea(child, PT_AR_EC, &ec, 1);
1103 	retval |= access_uarea(child, PT_AR_LC, &lc, 1);
1104 	retval |= access_uarea(child, PT_AR_RNAT, &rnat, 1);
1105 	retval |= access_uarea(child, PT_AR_BSP, &bsp, 1);
1106 	retval |= access_uarea(child, PT_CFM, &cfm, 1);
1107 	retval |= access_uarea(child, PT_NAT_BITS, &nat_bits, 1);
1108 
1109 	ret = retval ? -EIO : 0;
1110 	return ret;
1111 }
1112 
1113 void
1114 user_enable_single_step (struct task_struct *child)
1115 {
1116 	struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
1117 
1118 	set_tsk_thread_flag(child, TIF_SINGLESTEP);
1119 	child_psr->ss = 1;
1120 }
1121 
1122 void
1123 user_enable_block_step (struct task_struct *child)
1124 {
1125 	struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
1126 
1127 	set_tsk_thread_flag(child, TIF_SINGLESTEP);
1128 	child_psr->tb = 1;
1129 }
1130 
1131 void
1132 user_disable_single_step (struct task_struct *child)
1133 {
1134 	struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
1135 
1136 	/* make sure the single step/taken-branch trap bits are not set: */
1137 	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
1138 	child_psr->ss = 0;
1139 	child_psr->tb = 0;
1140 }
1141 
1142 /*
1143  * Called by kernel/ptrace.c when detaching..
1144  *
1145  * Make sure the single step bit is not set.
1146  */
1147 void
1148 ptrace_disable (struct task_struct *child)
1149 {
1150 	user_disable_single_step(child);
1151 }
1152 
1153 long
1154 arch_ptrace (struct task_struct *child, long request,
1155 	     unsigned long addr, unsigned long data)
1156 {
1157 	switch (request) {
1158 	case PTRACE_PEEKTEXT:
1159 	case PTRACE_PEEKDATA:
1160 		/* read word at location addr */
1161 		if (ptrace_access_vm(child, addr, &data, sizeof(data),
1162 				FOLL_FORCE)
1163 		    != sizeof(data))
1164 			return -EIO;
1165 		/* ensure return value is not mistaken for error code */
1166 		force_successful_syscall_return();
1167 		return data;
1168 
1169 	/* PTRACE_POKETEXT and PTRACE_POKEDATA is handled
1170 	 * by the generic ptrace_request().
1171 	 */
1172 
1173 	case PTRACE_PEEKUSR:
1174 		/* read the word at addr in the USER area */
1175 		if (access_uarea(child, addr, &data, 0) < 0)
1176 			return -EIO;
1177 		/* ensure return value is not mistaken for error code */
1178 		force_successful_syscall_return();
1179 		return data;
1180 
1181 	case PTRACE_POKEUSR:
1182 		/* write the word at addr in the USER area */
1183 		if (access_uarea(child, addr, &data, 1) < 0)
1184 			return -EIO;
1185 		return 0;
1186 
1187 	case PTRACE_OLD_GETSIGINFO:
1188 		/* for backwards-compatibility */
1189 		return ptrace_request(child, PTRACE_GETSIGINFO, addr, data);
1190 
1191 	case PTRACE_OLD_SETSIGINFO:
1192 		/* for backwards-compatibility */
1193 		return ptrace_request(child, PTRACE_SETSIGINFO, addr, data);
1194 
1195 	case PTRACE_GETREGS:
1196 		return ptrace_getregs(child,
1197 				      (struct pt_all_user_regs __user *) data);
1198 
1199 	case PTRACE_SETREGS:
1200 		return ptrace_setregs(child,
1201 				      (struct pt_all_user_regs __user *) data);
1202 
1203 	default:
1204 		return ptrace_request(child, request, addr, data);
1205 	}
1206 }
1207 
1208 
1209 /* "asmlinkage" so the input arguments are preserved... */
1210 
1211 asmlinkage long
1212 syscall_trace_enter (long arg0, long arg1, long arg2, long arg3,
1213 		     long arg4, long arg5, long arg6, long arg7,
1214 		     struct pt_regs regs)
1215 {
1216 	if (test_thread_flag(TIF_SYSCALL_TRACE))
1217 		if (tracehook_report_syscall_entry(&regs))
1218 			return -ENOSYS;
1219 
1220 	/* copy user rbs to kernel rbs */
1221 	if (test_thread_flag(TIF_RESTORE_RSE))
1222 		ia64_sync_krbs();
1223 
1224 
1225 	audit_syscall_entry(regs.r15, arg0, arg1, arg2, arg3);
1226 
1227 	return 0;
1228 }
1229 
1230 /* "asmlinkage" so the input arguments are preserved... */
1231 
1232 asmlinkage void
1233 syscall_trace_leave (long arg0, long arg1, long arg2, long arg3,
1234 		     long arg4, long arg5, long arg6, long arg7,
1235 		     struct pt_regs regs)
1236 {
1237 	int step;
1238 
1239 	audit_syscall_exit(&regs);
1240 
1241 	step = test_thread_flag(TIF_SINGLESTEP);
1242 	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1243 		tracehook_report_syscall_exit(&regs, step);
1244 
1245 	/* copy user rbs to kernel rbs */
1246 	if (test_thread_flag(TIF_RESTORE_RSE))
1247 		ia64_sync_krbs();
1248 }
1249 
1250 /* Utrace implementation starts here */
1251 struct regset_get {
1252 	void *kbuf;
1253 	void __user *ubuf;
1254 };
1255 
1256 struct regset_set {
1257 	const void *kbuf;
1258 	const void __user *ubuf;
1259 };
1260 
1261 struct regset_getset {
1262 	struct task_struct *target;
1263 	const struct user_regset *regset;
1264 	union {
1265 		struct regset_get get;
1266 		struct regset_set set;
1267 	} u;
1268 	unsigned int pos;
1269 	unsigned int count;
1270 	int ret;
1271 };
1272 
1273 static const ptrdiff_t pt_offsets[32] =
1274 {
1275 #define R(n) offsetof(struct pt_regs, r##n)
1276 	[0] = -1, R(1), R(2), R(3),
1277 	[4] = -1, [5] = -1, [6] = -1, [7] = -1,
1278 	R(8), R(9), R(10), R(11), R(12), R(13), R(14), R(15),
1279 	R(16), R(17), R(18), R(19), R(20), R(21), R(22), R(23),
1280 	R(24), R(25), R(26), R(27), R(28), R(29), R(30), R(31),
1281 #undef R
1282 };
1283 
1284 static int
1285 access_elf_gpreg(struct task_struct *target, struct unw_frame_info *info,
1286 		unsigned long addr, unsigned long *data, int write_access)
1287 {
1288 	struct pt_regs *pt = task_pt_regs(target);
1289 	unsigned reg = addr / sizeof(unsigned long);
1290 	ptrdiff_t d = pt_offsets[reg];
1291 
1292 	if (d >= 0) {
1293 		unsigned long *ptr = (void *)pt + d;
1294 		if (write_access)
1295 			*ptr = *data;
1296 		else
1297 			*data = *ptr;
1298 		return 0;
1299 	} else {
1300 		char nat = 0;
1301 		if (write_access) {
1302 			/* read NaT bit first: */
1303 			unsigned long dummy;
1304 			int ret = unw_get_gr(info, reg, &dummy, &nat);
1305 			if (ret < 0)
1306 				return ret;
1307 		}
1308 		return unw_access_gr(info, reg, data, &nat, write_access);
1309 	}
1310 }
1311 
1312 static int
1313 access_elf_breg(struct task_struct *target, struct unw_frame_info *info,
1314 		unsigned long addr, unsigned long *data, int write_access)
1315 {
1316 	struct pt_regs *pt;
1317 	unsigned long *ptr = NULL;
1318 
1319 	pt = task_pt_regs(target);
1320 	switch (addr) {
1321 	case ELF_BR_OFFSET(0):
1322 		ptr = &pt->b0;
1323 		break;
1324 	case ELF_BR_OFFSET(1) ... ELF_BR_OFFSET(5):
1325 		return unw_access_br(info, (addr - ELF_BR_OFFSET(0))/8,
1326 				     data, write_access);
1327 	case ELF_BR_OFFSET(6):
1328 		ptr = &pt->b6;
1329 		break;
1330 	case ELF_BR_OFFSET(7):
1331 		ptr = &pt->b7;
1332 	}
1333 	if (write_access)
1334 		*ptr = *data;
1335 	else
1336 		*data = *ptr;
1337 	return 0;
1338 }
1339 
1340 static int
1341 access_elf_areg(struct task_struct *target, struct unw_frame_info *info,
1342 		unsigned long addr, unsigned long *data, int write_access)
1343 {
1344 	struct pt_regs *pt;
1345 	unsigned long cfm, urbs_end;
1346 	unsigned long *ptr = NULL;
1347 
1348 	pt = task_pt_regs(target);
1349 	if (addr >= ELF_AR_RSC_OFFSET && addr <= ELF_AR_SSD_OFFSET) {
1350 		switch (addr) {
1351 		case ELF_AR_RSC_OFFSET:
1352 			/* force PL3 */
1353 			if (write_access)
1354 				pt->ar_rsc = *data | (3 << 2);
1355 			else
1356 				*data = pt->ar_rsc;
1357 			return 0;
1358 		case ELF_AR_BSP_OFFSET:
1359 			/*
1360 			 * By convention, we use PT_AR_BSP to refer to
1361 			 * the end of the user-level backing store.
1362 			 * Use ia64_rse_skip_regs(PT_AR_BSP, -CFM.sof)
1363 			 * to get the real value of ar.bsp at the time
1364 			 * the kernel was entered.
1365 			 *
1366 			 * Furthermore, when changing the contents of
1367 			 * PT_AR_BSP (or PT_CFM) while the task is
1368 			 * blocked in a system call, convert the state
1369 			 * so that the non-system-call exit
1370 			 * path is used.  This ensures that the proper
1371 			 * state will be picked up when resuming
1372 			 * execution.  However, it *also* means that
1373 			 * once we write PT_AR_BSP/PT_CFM, it won't be
1374 			 * possible to modify the syscall arguments of
1375 			 * the pending system call any longer.  This
1376 			 * shouldn't be an issue because modifying
1377 			 * PT_AR_BSP/PT_CFM generally implies that
1378 			 * we're either abandoning the pending system
1379 			 * call or that we defer it's re-execution
1380 			 * (e.g., due to GDB doing an inferior
1381 			 * function call).
1382 			 */
1383 			urbs_end = ia64_get_user_rbs_end(target, pt, &cfm);
1384 			if (write_access) {
1385 				if (*data != urbs_end) {
1386 					if (in_syscall(pt))
1387 						convert_to_non_syscall(target,
1388 								       pt,
1389 								       cfm);
1390 					/*
1391 					 * Simulate user-level write
1392 					 * of ar.bsp:
1393 					 */
1394 					pt->loadrs = 0;
1395 					pt->ar_bspstore = *data;
1396 				}
1397 			} else
1398 				*data = urbs_end;
1399 			return 0;
1400 		case ELF_AR_BSPSTORE_OFFSET:
1401 			ptr = &pt->ar_bspstore;
1402 			break;
1403 		case ELF_AR_RNAT_OFFSET:
1404 			ptr = &pt->ar_rnat;
1405 			break;
1406 		case ELF_AR_CCV_OFFSET:
1407 			ptr = &pt->ar_ccv;
1408 			break;
1409 		case ELF_AR_UNAT_OFFSET:
1410 			ptr = &pt->ar_unat;
1411 			break;
1412 		case ELF_AR_FPSR_OFFSET:
1413 			ptr = &pt->ar_fpsr;
1414 			break;
1415 		case ELF_AR_PFS_OFFSET:
1416 			ptr = &pt->ar_pfs;
1417 			break;
1418 		case ELF_AR_LC_OFFSET:
1419 			return unw_access_ar(info, UNW_AR_LC, data,
1420 					     write_access);
1421 		case ELF_AR_EC_OFFSET:
1422 			return unw_access_ar(info, UNW_AR_EC, data,
1423 					     write_access);
1424 		case ELF_AR_CSD_OFFSET:
1425 			ptr = &pt->ar_csd;
1426 			break;
1427 		case ELF_AR_SSD_OFFSET:
1428 			ptr = &pt->ar_ssd;
1429 		}
1430 	} else if (addr >= ELF_CR_IIP_OFFSET && addr <= ELF_CR_IPSR_OFFSET) {
1431 		switch (addr) {
1432 		case ELF_CR_IIP_OFFSET:
1433 			ptr = &pt->cr_iip;
1434 			break;
1435 		case ELF_CFM_OFFSET:
1436 			urbs_end = ia64_get_user_rbs_end(target, pt, &cfm);
1437 			if (write_access) {
1438 				if (((cfm ^ *data) & PFM_MASK) != 0) {
1439 					if (in_syscall(pt))
1440 						convert_to_non_syscall(target,
1441 								       pt,
1442 								       cfm);
1443 					pt->cr_ifs = ((pt->cr_ifs & ~PFM_MASK)
1444 						      | (*data & PFM_MASK));
1445 				}
1446 			} else
1447 				*data = cfm;
1448 			return 0;
1449 		case ELF_CR_IPSR_OFFSET:
1450 			if (write_access) {
1451 				unsigned long tmp = *data;
1452 				/* psr.ri==3 is a reserved value: SDM 2:25 */
1453 				if ((tmp & IA64_PSR_RI) == IA64_PSR_RI)
1454 					tmp &= ~IA64_PSR_RI;
1455 				pt->cr_ipsr = ((tmp & IPSR_MASK)
1456 					       | (pt->cr_ipsr & ~IPSR_MASK));
1457 			} else
1458 				*data = (pt->cr_ipsr & IPSR_MASK);
1459 			return 0;
1460 		}
1461 	} else if (addr == ELF_NAT_OFFSET)
1462 		return access_nat_bits(target, pt, info,
1463 				       data, write_access);
1464 	else if (addr == ELF_PR_OFFSET)
1465 		ptr = &pt->pr;
1466 	else
1467 		return -1;
1468 
1469 	if (write_access)
1470 		*ptr = *data;
1471 	else
1472 		*data = *ptr;
1473 
1474 	return 0;
1475 }
1476 
1477 static int
1478 access_elf_reg(struct task_struct *target, struct unw_frame_info *info,
1479 		unsigned long addr, unsigned long *data, int write_access)
1480 {
1481 	if (addr >= ELF_GR_OFFSET(1) && addr <= ELF_GR_OFFSET(31))
1482 		return access_elf_gpreg(target, info, addr, data, write_access);
1483 	else if (addr >= ELF_BR_OFFSET(0) && addr <= ELF_BR_OFFSET(7))
1484 		return access_elf_breg(target, info, addr, data, write_access);
1485 	else
1486 		return access_elf_areg(target, info, addr, data, write_access);
1487 }
1488 
1489 struct regset_membuf {
1490 	struct membuf to;
1491 	int ret;
1492 };
1493 
1494 void do_gpregs_get(struct unw_frame_info *info, void *arg)
1495 {
1496 	struct regset_membuf *dst = arg;
1497 	struct membuf to = dst->to;
1498 	unsigned int n;
1499 	elf_greg_t reg;
1500 
1501 	if (unw_unwind_to_user(info) < 0)
1502 		return;
1503 
1504 	/*
1505 	 * coredump format:
1506 	 *      r0-r31
1507 	 *      NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
1508 	 *      predicate registers (p0-p63)
1509 	 *      b0-b7
1510 	 *      ip cfm user-mask
1511 	 *      ar.rsc ar.bsp ar.bspstore ar.rnat
1512 	 *      ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
1513 	 */
1514 
1515 
1516 	/* Skip r0 */
1517 	membuf_zero(&to, 8);
1518 	for (n = 8; to.left && n < ELF_AR_END_OFFSET; n += 8) {
1519 		if (access_elf_reg(info->task, info, n, &reg, 0) < 0) {
1520 			dst->ret = -EIO;
1521 			return;
1522 		}
1523 		membuf_store(&to, reg);
1524 	}
1525 }
1526 
1527 void do_gpregs_set(struct unw_frame_info *info, void *arg)
1528 {
1529 	struct regset_getset *dst = arg;
1530 
1531 	if (unw_unwind_to_user(info) < 0)
1532 		return;
1533 
1534 	if (!dst->count)
1535 		return;
1536 	/* Skip r0 */
1537 	if (dst->pos < ELF_GR_OFFSET(1)) {
1538 		dst->ret = user_regset_copyin_ignore(&dst->pos, &dst->count,
1539 						       &dst->u.set.kbuf,
1540 						       &dst->u.set.ubuf,
1541 						       0, ELF_GR_OFFSET(1));
1542 		if (dst->ret)
1543 			return;
1544 	}
1545 
1546 	while (dst->count && dst->pos < ELF_AR_END_OFFSET) {
1547 		unsigned int n, from, to;
1548 		elf_greg_t tmp[16];
1549 
1550 		from = dst->pos;
1551 		to = from + sizeof(tmp);
1552 		if (to > ELF_AR_END_OFFSET)
1553 			to = ELF_AR_END_OFFSET;
1554 		/* get up to 16 values */
1555 		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1556 				&dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
1557 				from, to);
1558 		if (dst->ret)
1559 			return;
1560 		/* now copy them into registers */
1561 		for (n = 0; from < dst->pos; from += sizeof(elf_greg_t), n++)
1562 			if (access_elf_reg(dst->target, info, from,
1563 						&tmp[n], 1) < 0) {
1564 				dst->ret = -EIO;
1565 				return;
1566 			}
1567 	}
1568 }
1569 
1570 #define ELF_FP_OFFSET(i)	(i * sizeof(elf_fpreg_t))
1571 
1572 void do_fpregs_get(struct unw_frame_info *info, void *arg)
1573 {
1574 	struct task_struct *task = info->task;
1575 	struct regset_membuf *dst = arg;
1576 	struct membuf to = dst->to;
1577 	elf_fpreg_t reg;
1578 	unsigned int n;
1579 
1580 	if (unw_unwind_to_user(info) < 0)
1581 		return;
1582 
1583 	/* Skip pos 0 and 1 */
1584 	membuf_zero(&to, 2 * sizeof(elf_fpreg_t));
1585 
1586 	/* fr2-fr31 */
1587 	for (n = 2; to.left && n < 32; n++) {
1588 		if (unw_get_fr(info, n, &reg)) {
1589 			dst->ret = -EIO;
1590 			return;
1591 		}
1592 		membuf_write(&to, &reg, sizeof(reg));
1593 	}
1594 
1595 	/* fph */
1596 	if (!to.left)
1597 		return;
1598 
1599 	ia64_flush_fph(task);
1600 	if (task->thread.flags & IA64_THREAD_FPH_VALID)
1601 		membuf_write(&to, &task->thread.fph, 96 * sizeof(reg));
1602 	else
1603 		membuf_zero(&to, 96 * sizeof(reg));
1604 }
1605 
1606 void do_fpregs_set(struct unw_frame_info *info, void *arg)
1607 {
1608 	struct regset_getset *dst = arg;
1609 	elf_fpreg_t fpreg, tmp[30];
1610 	int index, start, end;
1611 
1612 	if (unw_unwind_to_user(info) < 0)
1613 		return;
1614 
1615 	/* Skip pos 0 and 1 */
1616 	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(2)) {
1617 		dst->ret = user_regset_copyin_ignore(&dst->pos, &dst->count,
1618 						       &dst->u.set.kbuf,
1619 						       &dst->u.set.ubuf,
1620 						       0, ELF_FP_OFFSET(2));
1621 		if (dst->count == 0 || dst->ret)
1622 			return;
1623 	}
1624 
1625 	/* fr2-fr31 */
1626 	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(32)) {
1627 		start = dst->pos;
1628 		end = min(((unsigned int)ELF_FP_OFFSET(32)),
1629 			 dst->pos + dst->count);
1630 		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1631 				&dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
1632 				ELF_FP_OFFSET(2), ELF_FP_OFFSET(32));
1633 		if (dst->ret)
1634 			return;
1635 
1636 		if (start & 0xF) { /* only write high part */
1637 			if (unw_get_fr(info, start / sizeof(elf_fpreg_t),
1638 					 &fpreg)) {
1639 				dst->ret = -EIO;
1640 				return;
1641 			}
1642 			tmp[start / sizeof(elf_fpreg_t) - 2].u.bits[0]
1643 				= fpreg.u.bits[0];
1644 			start &= ~0xFUL;
1645 		}
1646 		if (end & 0xF) { /* only write low part */
1647 			if (unw_get_fr(info, end / sizeof(elf_fpreg_t),
1648 					&fpreg)) {
1649 				dst->ret = -EIO;
1650 				return;
1651 			}
1652 			tmp[end / sizeof(elf_fpreg_t) - 2].u.bits[1]
1653 				= fpreg.u.bits[1];
1654 			end = (end + 0xF) & ~0xFUL;
1655 		}
1656 
1657 		for ( ;	start < end ; start += sizeof(elf_fpreg_t)) {
1658 			index = start / sizeof(elf_fpreg_t);
1659 			if (unw_set_fr(info, index, tmp[index - 2])) {
1660 				dst->ret = -EIO;
1661 				return;
1662 			}
1663 		}
1664 		if (dst->ret || dst->count == 0)
1665 			return;
1666 	}
1667 
1668 	/* fph */
1669 	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(128)) {
1670 		ia64_sync_fph(dst->target);
1671 		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1672 						&dst->u.set.kbuf,
1673 						&dst->u.set.ubuf,
1674 						&dst->target->thread.fph,
1675 						ELF_FP_OFFSET(32), -1);
1676 	}
1677 }
1678 
1679 static void
1680 unwind_and_call(void (*call)(struct unw_frame_info *, void *),
1681 	       struct task_struct *target, void *data)
1682 {
1683 	if (target == current)
1684 		unw_init_running(call, data);
1685 	else {
1686 		struct unw_frame_info info;
1687 		memset(&info, 0, sizeof(info));
1688 		unw_init_from_blocked_task(&info, target);
1689 		(*call)(&info, data);
1690 	}
1691 }
1692 
1693 static int
1694 do_regset_call(void (*call)(struct unw_frame_info *, void *),
1695 	       struct task_struct *target,
1696 	       const struct user_regset *regset,
1697 	       unsigned int pos, unsigned int count,
1698 	       const void *kbuf, const void __user *ubuf)
1699 {
1700 	struct regset_getset info = { .target = target, .regset = regset,
1701 				 .pos = pos, .count = count,
1702 				 .u.set = { .kbuf = kbuf, .ubuf = ubuf },
1703 				 .ret = 0 };
1704 	unwind_and_call(call, target, &info);
1705 	return info.ret;
1706 }
1707 
1708 static int
1709 gpregs_get(struct task_struct *target,
1710 	   const struct user_regset *regset,
1711 	   struct membuf to)
1712 {
1713 	struct regset_membuf info = {.to = to};
1714 	unwind_and_call(do_gpregs_get, target, &info);
1715 	return info.ret;
1716 }
1717 
1718 static int gpregs_set(struct task_struct *target,
1719 		const struct user_regset *regset,
1720 		unsigned int pos, unsigned int count,
1721 		const void *kbuf, const void __user *ubuf)
1722 {
1723 	return do_regset_call(do_gpregs_set, target, regset, pos, count,
1724 		kbuf, ubuf);
1725 }
1726 
1727 static void do_gpregs_writeback(struct unw_frame_info *info, void *arg)
1728 {
1729 	do_sync_rbs(info, ia64_sync_user_rbs);
1730 }
1731 
1732 /*
1733  * This is called to write back the register backing store.
1734  * ptrace does this before it stops, so that a tracer reading the user
1735  * memory after the thread stops will get the current register data.
1736  */
1737 static int
1738 gpregs_writeback(struct task_struct *target,
1739 		 const struct user_regset *regset,
1740 		 int now)
1741 {
1742 	if (test_and_set_tsk_thread_flag(target, TIF_RESTORE_RSE))
1743 		return 0;
1744 	set_notify_resume(target);
1745 	return do_regset_call(do_gpregs_writeback, target, regset, 0, 0,
1746 		NULL, NULL);
1747 }
1748 
1749 static int
1750 fpregs_active(struct task_struct *target, const struct user_regset *regset)
1751 {
1752 	return (target->thread.flags & IA64_THREAD_FPH_VALID) ? 128 : 32;
1753 }
1754 
1755 static int fpregs_get(struct task_struct *target,
1756 		const struct user_regset *regset,
1757 		struct membuf to)
1758 {
1759 	struct regset_membuf info = {.to = to};
1760 	unwind_and_call(do_fpregs_get, target, &info);
1761 	return info.ret;
1762 }
1763 
1764 static int fpregs_set(struct task_struct *target,
1765 		const struct user_regset *regset,
1766 		unsigned int pos, unsigned int count,
1767 		const void *kbuf, const void __user *ubuf)
1768 {
1769 	return do_regset_call(do_fpregs_set, target, regset, pos, count,
1770 		kbuf, ubuf);
1771 }
1772 
1773 static int
1774 access_uarea(struct task_struct *child, unsigned long addr,
1775 	      unsigned long *data, int write_access)
1776 {
1777 	unsigned int pos = -1; /* an invalid value */
1778 	unsigned long *ptr, regnum;
1779 
1780 	if ((addr & 0x7) != 0) {
1781 		dprintk("ptrace: unaligned register address 0x%lx\n", addr);
1782 		return -1;
1783 	}
1784 	if ((addr >= PT_NAT_BITS + 8 && addr < PT_F2) ||
1785 		(addr >= PT_R7 + 8 && addr < PT_B1) ||
1786 		(addr >= PT_AR_LC + 8 && addr < PT_CR_IPSR) ||
1787 		(addr >= PT_AR_SSD + 8 && addr < PT_DBR)) {
1788 		dprintk("ptrace: rejecting access to register "
1789 					"address 0x%lx\n", addr);
1790 		return -1;
1791 	}
1792 
1793 	switch (addr) {
1794 	case PT_F32 ... (PT_F127 + 15):
1795 		pos = addr - PT_F32 + ELF_FP_OFFSET(32);
1796 		break;
1797 	case PT_F2 ... (PT_F5 + 15):
1798 		pos = addr - PT_F2 + ELF_FP_OFFSET(2);
1799 		break;
1800 	case PT_F10 ... (PT_F31 + 15):
1801 		pos = addr - PT_F10 + ELF_FP_OFFSET(10);
1802 		break;
1803 	case PT_F6 ... (PT_F9 + 15):
1804 		pos = addr - PT_F6 + ELF_FP_OFFSET(6);
1805 		break;
1806 	}
1807 
1808 	if (pos != -1) {
1809 		unsigned reg = pos / sizeof(elf_fpreg_t);
1810 		int which_half = (pos / sizeof(unsigned long)) & 1;
1811 
1812 		if (reg < 32) { /* fr2-fr31 */
1813 			struct unw_frame_info info;
1814 			elf_fpreg_t fpreg;
1815 
1816 			memset(&info, 0, sizeof(info));
1817 			unw_init_from_blocked_task(&info, child);
1818 			if (unw_unwind_to_user(&info) < 0)
1819 				return 0;
1820 
1821 			if (unw_get_fr(&info, reg, &fpreg))
1822 				return -1;
1823 			if (write_access) {
1824 				fpreg.u.bits[which_half] = *data;
1825 				if (unw_set_fr(&info, reg, fpreg))
1826 					return -1;
1827 			} else {
1828 				*data = fpreg.u.bits[which_half];
1829 			}
1830 		} else { /* fph */
1831 			elf_fpreg_t *p = &child->thread.fph[reg - 32];
1832 			unsigned long *bits = &p->u.bits[which_half];
1833 
1834 			ia64_sync_fph(child);
1835 			if (write_access)
1836 				*bits = *data;
1837 			else if (child->thread.flags & IA64_THREAD_FPH_VALID)
1838 				*data = *bits;
1839 			else
1840 				*data = 0;
1841 		}
1842 		return 0;
1843 	}
1844 
1845 	switch (addr) {
1846 	case PT_NAT_BITS:
1847 		pos = ELF_NAT_OFFSET;
1848 		break;
1849 	case PT_R4 ... PT_R7:
1850 		pos = addr - PT_R4 + ELF_GR_OFFSET(4);
1851 		break;
1852 	case PT_B1 ... PT_B5:
1853 		pos = addr - PT_B1 + ELF_BR_OFFSET(1);
1854 		break;
1855 	case PT_AR_EC:
1856 		pos = ELF_AR_EC_OFFSET;
1857 		break;
1858 	case PT_AR_LC:
1859 		pos = ELF_AR_LC_OFFSET;
1860 		break;
1861 	case PT_CR_IPSR:
1862 		pos = ELF_CR_IPSR_OFFSET;
1863 		break;
1864 	case PT_CR_IIP:
1865 		pos = ELF_CR_IIP_OFFSET;
1866 		break;
1867 	case PT_CFM:
1868 		pos = ELF_CFM_OFFSET;
1869 		break;
1870 	case PT_AR_UNAT:
1871 		pos = ELF_AR_UNAT_OFFSET;
1872 		break;
1873 	case PT_AR_PFS:
1874 		pos = ELF_AR_PFS_OFFSET;
1875 		break;
1876 	case PT_AR_RSC:
1877 		pos = ELF_AR_RSC_OFFSET;
1878 		break;
1879 	case PT_AR_RNAT:
1880 		pos = ELF_AR_RNAT_OFFSET;
1881 		break;
1882 	case PT_AR_BSPSTORE:
1883 		pos = ELF_AR_BSPSTORE_OFFSET;
1884 		break;
1885 	case PT_PR:
1886 		pos = ELF_PR_OFFSET;
1887 		break;
1888 	case PT_B6:
1889 		pos = ELF_BR_OFFSET(6);
1890 		break;
1891 	case PT_AR_BSP:
1892 		pos = ELF_AR_BSP_OFFSET;
1893 		break;
1894 	case PT_R1 ... PT_R3:
1895 		pos = addr - PT_R1 + ELF_GR_OFFSET(1);
1896 		break;
1897 	case PT_R12 ... PT_R15:
1898 		pos = addr - PT_R12 + ELF_GR_OFFSET(12);
1899 		break;
1900 	case PT_R8 ... PT_R11:
1901 		pos = addr - PT_R8 + ELF_GR_OFFSET(8);
1902 		break;
1903 	case PT_R16 ... PT_R31:
1904 		pos = addr - PT_R16 + ELF_GR_OFFSET(16);
1905 		break;
1906 	case PT_AR_CCV:
1907 		pos = ELF_AR_CCV_OFFSET;
1908 		break;
1909 	case PT_AR_FPSR:
1910 		pos = ELF_AR_FPSR_OFFSET;
1911 		break;
1912 	case PT_B0:
1913 		pos = ELF_BR_OFFSET(0);
1914 		break;
1915 	case PT_B7:
1916 		pos = ELF_BR_OFFSET(7);
1917 		break;
1918 	case PT_AR_CSD:
1919 		pos = ELF_AR_CSD_OFFSET;
1920 		break;
1921 	case PT_AR_SSD:
1922 		pos = ELF_AR_SSD_OFFSET;
1923 		break;
1924 	}
1925 
1926 	if (pos != -1) {
1927 		struct unw_frame_info info;
1928 
1929 		memset(&info, 0, sizeof(info));
1930 		unw_init_from_blocked_task(&info, child);
1931 		if (unw_unwind_to_user(&info) < 0)
1932 			return 0;
1933 
1934 		return access_elf_reg(child, &info, pos, data, write_access);
1935 	}
1936 
1937 	/* access debug registers */
1938 	if (addr >= PT_IBR) {
1939 		regnum = (addr - PT_IBR) >> 3;
1940 		ptr = &child->thread.ibr[0];
1941 	} else {
1942 		regnum = (addr - PT_DBR) >> 3;
1943 		ptr = &child->thread.dbr[0];
1944 	}
1945 
1946 	if (regnum >= 8) {
1947 		dprintk("ptrace: rejecting access to register "
1948 				"address 0x%lx\n", addr);
1949 		return -1;
1950 	}
1951 
1952 	if (!(child->thread.flags & IA64_THREAD_DBG_VALID)) {
1953 		child->thread.flags |= IA64_THREAD_DBG_VALID;
1954 		memset(child->thread.dbr, 0,
1955 				sizeof(child->thread.dbr));
1956 		memset(child->thread.ibr, 0,
1957 				sizeof(child->thread.ibr));
1958 	}
1959 
1960 	ptr += regnum;
1961 
1962 	if ((regnum & 1) && write_access) {
1963 		/* don't let the user set kernel-level breakpoints: */
1964 		*ptr = *data & ~(7UL << 56);
1965 		return 0;
1966 	}
1967 	if (write_access)
1968 		*ptr = *data;
1969 	else
1970 		*data = *ptr;
1971 	return 0;
1972 }
1973 
1974 static const struct user_regset native_regsets[] = {
1975 	{
1976 		.core_note_type = NT_PRSTATUS,
1977 		.n = ELF_NGREG,
1978 		.size = sizeof(elf_greg_t), .align = sizeof(elf_greg_t),
1979 		.regset_get = gpregs_get, .set = gpregs_set,
1980 		.writeback = gpregs_writeback
1981 	},
1982 	{
1983 		.core_note_type = NT_PRFPREG,
1984 		.n = ELF_NFPREG,
1985 		.size = sizeof(elf_fpreg_t), .align = sizeof(elf_fpreg_t),
1986 		.regset_get = fpregs_get, .set = fpregs_set, .active = fpregs_active
1987 	},
1988 };
1989 
1990 static const struct user_regset_view user_ia64_view = {
1991 	.name = "ia64",
1992 	.e_machine = EM_IA_64,
1993 	.regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
1994 };
1995 
1996 const struct user_regset_view *task_user_regset_view(struct task_struct *tsk)
1997 {
1998 	return &user_ia64_view;
1999 }
2000 
2001 struct syscall_get_set_args {
2002 	unsigned int i;
2003 	unsigned int n;
2004 	unsigned long *args;
2005 	struct pt_regs *regs;
2006 	int rw;
2007 };
2008 
2009 static void syscall_get_set_args_cb(struct unw_frame_info *info, void *data)
2010 {
2011 	struct syscall_get_set_args *args = data;
2012 	struct pt_regs *pt = args->regs;
2013 	unsigned long *krbs, cfm, ndirty;
2014 	int i, count;
2015 
2016 	if (unw_unwind_to_user(info) < 0)
2017 		return;
2018 
2019 	cfm = pt->cr_ifs;
2020 	krbs = (unsigned long *)info->task + IA64_RBS_OFFSET/8;
2021 	ndirty = ia64_rse_num_regs(krbs, krbs + (pt->loadrs >> 19));
2022 
2023 	count = 0;
2024 	if (in_syscall(pt))
2025 		count = min_t(int, args->n, cfm & 0x7f);
2026 
2027 	for (i = 0; i < count; i++) {
2028 		if (args->rw)
2029 			*ia64_rse_skip_regs(krbs, ndirty + i + args->i) =
2030 				args->args[i];
2031 		else
2032 			args->args[i] = *ia64_rse_skip_regs(krbs,
2033 				ndirty + i + args->i);
2034 	}
2035 
2036 	if (!args->rw) {
2037 		while (i < args->n) {
2038 			args->args[i] = 0;
2039 			i++;
2040 		}
2041 	}
2042 }
2043 
2044 void ia64_syscall_get_set_arguments(struct task_struct *task,
2045 	struct pt_regs *regs, unsigned long *args, int rw)
2046 {
2047 	struct syscall_get_set_args data = {
2048 		.i = 0,
2049 		.n = 6,
2050 		.args = args,
2051 		.regs = regs,
2052 		.rw = rw,
2053 	};
2054 
2055 	if (task == current)
2056 		unw_init_running(syscall_get_set_args_cb, &data);
2057 	else {
2058 		struct unw_frame_info ufi;
2059 		memset(&ufi, 0, sizeof(ufi));
2060 		unw_init_from_blocked_task(&ufi, task);
2061 		syscall_get_set_args_cb(&ufi, &data);
2062 	}
2063 }
2064