xref: /openbmc/linux/arch/ia64/kernel/ptrace.c (revision dea54fba)
1 /*
2  * Kernel support for the ptrace() and syscall tracing interfaces.
3  *
4  * Copyright (C) 1999-2005 Hewlett-Packard Co
5  *	David Mosberger-Tang <davidm@hpl.hp.com>
6  * Copyright (C) 2006 Intel Co
7  *  2006-08-12	- IA64 Native Utrace implementation support added by
8  *	Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
9  *
10  * Derived from the x86 and Alpha versions.
11  */
12 #include <linux/kernel.h>
13 #include <linux/sched.h>
14 #include <linux/sched/task.h>
15 #include <linux/sched/task_stack.h>
16 #include <linux/mm.h>
17 #include <linux/errno.h>
18 #include <linux/ptrace.h>
19 #include <linux/user.h>
20 #include <linux/security.h>
21 #include <linux/audit.h>
22 #include <linux/signal.h>
23 #include <linux/regset.h>
24 #include <linux/elf.h>
25 #include <linux/tracehook.h>
26 
27 #include <asm/pgtable.h>
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 #ifdef CONFIG_PERFMON
34 #include <asm/perfmon.h>
35 #endif
36 
37 #include "entry.h"
38 
39 /*
40  * Bits in the PSR that we allow ptrace() to change:
41  *	be, up, ac, mfl, mfh (the user mask; five bits total)
42  *	db (debug breakpoint fault; one bit)
43  *	id (instruction debug fault disable; one bit)
44  *	dd (data debug fault disable; one bit)
45  *	ri (restart instruction; two bits)
46  *	is (instruction set; one bit)
47  */
48 #define IPSR_MASK (IA64_PSR_UM | IA64_PSR_DB | IA64_PSR_IS	\
49 		   | IA64_PSR_ID | IA64_PSR_DD | IA64_PSR_RI)
50 
51 #define MASK(nbits)	((1UL << (nbits)) - 1)	/* mask with NBITS bits set */
52 #define PFM_MASK	MASK(38)
53 
54 #define PTRACE_DEBUG	0
55 
56 #if PTRACE_DEBUG
57 # define dprintk(format...)	printk(format)
58 # define inline
59 #else
60 # define dprintk(format...)
61 #endif
62 
63 /* Return TRUE if PT was created due to kernel-entry via a system-call.  */
64 
65 static inline int
66 in_syscall (struct pt_regs *pt)
67 {
68 	return (long) pt->cr_ifs >= 0;
69 }
70 
71 /*
72  * Collect the NaT bits for r1-r31 from scratch_unat and return a NaT
73  * bitset where bit i is set iff the NaT bit of register i is set.
74  */
75 unsigned long
76 ia64_get_scratch_nat_bits (struct pt_regs *pt, unsigned long scratch_unat)
77 {
78 #	define GET_BITS(first, last, unat)				\
79 	({								\
80 		unsigned long bit = ia64_unat_pos(&pt->r##first);	\
81 		unsigned long nbits = (last - first + 1);		\
82 		unsigned long mask = MASK(nbits) << first;		\
83 		unsigned long dist;					\
84 		if (bit < first)					\
85 			dist = 64 + bit - first;			\
86 		else							\
87 			dist = bit - first;				\
88 		ia64_rotr(unat, dist) & mask;				\
89 	})
90 	unsigned long val;
91 
92 	/*
93 	 * Registers that are stored consecutively in struct pt_regs
94 	 * can be handled in parallel.  If the register order in
95 	 * struct_pt_regs changes, this code MUST be updated.
96 	 */
97 	val  = GET_BITS( 1,  1, scratch_unat);
98 	val |= GET_BITS( 2,  3, scratch_unat);
99 	val |= GET_BITS(12, 13, scratch_unat);
100 	val |= GET_BITS(14, 14, scratch_unat);
101 	val |= GET_BITS(15, 15, scratch_unat);
102 	val |= GET_BITS( 8, 11, scratch_unat);
103 	val |= GET_BITS(16, 31, scratch_unat);
104 	return val;
105 
106 #	undef GET_BITS
107 }
108 
109 /*
110  * Set the NaT bits for the scratch registers according to NAT and
111  * return the resulting unat (assuming the scratch registers are
112  * stored in PT).
113  */
114 unsigned long
115 ia64_put_scratch_nat_bits (struct pt_regs *pt, unsigned long nat)
116 {
117 #	define PUT_BITS(first, last, nat)				\
118 	({								\
119 		unsigned long bit = ia64_unat_pos(&pt->r##first);	\
120 		unsigned long nbits = (last - first + 1);		\
121 		unsigned long mask = MASK(nbits) << first;		\
122 		long dist;						\
123 		if (bit < first)					\
124 			dist = 64 + bit - first;			\
125 		else							\
126 			dist = bit - first;				\
127 		ia64_rotl(nat & mask, dist);				\
128 	})
129 	unsigned long scratch_unat;
130 
131 	/*
132 	 * Registers that are stored consecutively in struct pt_regs
133 	 * can be handled in parallel.  If the register order in
134 	 * struct_pt_regs changes, this code MUST be updated.
135 	 */
136 	scratch_unat  = PUT_BITS( 1,  1, nat);
137 	scratch_unat |= PUT_BITS( 2,  3, nat);
138 	scratch_unat |= PUT_BITS(12, 13, nat);
139 	scratch_unat |= PUT_BITS(14, 14, nat);
140 	scratch_unat |= PUT_BITS(15, 15, nat);
141 	scratch_unat |= PUT_BITS( 8, 11, nat);
142 	scratch_unat |= PUT_BITS(16, 31, nat);
143 
144 	return scratch_unat;
145 
146 #	undef PUT_BITS
147 }
148 
149 #define IA64_MLX_TEMPLATE	0x2
150 #define IA64_MOVL_OPCODE	6
151 
152 void
153 ia64_increment_ip (struct pt_regs *regs)
154 {
155 	unsigned long w0, ri = ia64_psr(regs)->ri + 1;
156 
157 	if (ri > 2) {
158 		ri = 0;
159 		regs->cr_iip += 16;
160 	} else if (ri == 2) {
161 		get_user(w0, (char __user *) regs->cr_iip + 0);
162 		if (((w0 >> 1) & 0xf) == IA64_MLX_TEMPLATE) {
163 			/*
164 			 * rfi'ing to slot 2 of an MLX bundle causes
165 			 * an illegal operation fault.  We don't want
166 			 * that to happen...
167 			 */
168 			ri = 0;
169 			regs->cr_iip += 16;
170 		}
171 	}
172 	ia64_psr(regs)->ri = ri;
173 }
174 
175 void
176 ia64_decrement_ip (struct pt_regs *regs)
177 {
178 	unsigned long w0, ri = ia64_psr(regs)->ri - 1;
179 
180 	if (ia64_psr(regs)->ri == 0) {
181 		regs->cr_iip -= 16;
182 		ri = 2;
183 		get_user(w0, (char __user *) regs->cr_iip + 0);
184 		if (((w0 >> 1) & 0xf) == IA64_MLX_TEMPLATE) {
185 			/*
186 			 * rfi'ing to slot 2 of an MLX bundle causes
187 			 * an illegal operation fault.  We don't want
188 			 * that to happen...
189 			 */
190 			ri = 1;
191 		}
192 	}
193 	ia64_psr(regs)->ri = ri;
194 }
195 
196 /*
197  * This routine is used to read an rnat bits that are stored on the
198  * kernel backing store.  Since, in general, the alignment of the user
199  * and kernel are different, this is not completely trivial.  In
200  * essence, we need to construct the user RNAT based on up to two
201  * kernel RNAT values and/or the RNAT value saved in the child's
202  * pt_regs.
203  *
204  * user rbs
205  *
206  * +--------+ <-- lowest address
207  * | slot62 |
208  * +--------+
209  * |  rnat  | 0x....1f8
210  * +--------+
211  * | slot00 | \
212  * +--------+ |
213  * | slot01 | > child_regs->ar_rnat
214  * +--------+ |
215  * | slot02 | /				kernel rbs
216  * +--------+				+--------+
217  *	    <- child_regs->ar_bspstore	| slot61 | <-- krbs
218  * +- - - - +				+--------+
219  *					| slot62 |
220  * +- - - - +				+--------+
221  *					|  rnat	 |
222  * +- - - - +				+--------+
223  *   vrnat				| slot00 |
224  * +- - - - +				+--------+
225  *					=	 =
226  *					+--------+
227  *					| slot00 | \
228  *					+--------+ |
229  *					| slot01 | > child_stack->ar_rnat
230  *					+--------+ |
231  *					| slot02 | /
232  *					+--------+
233  *						  <--- child_stack->ar_bspstore
234  *
235  * The way to think of this code is as follows: bit 0 in the user rnat
236  * corresponds to some bit N (0 <= N <= 62) in one of the kernel rnat
237  * value.  The kernel rnat value holding this bit is stored in
238  * variable rnat0.  rnat1 is loaded with the kernel rnat value that
239  * form the upper bits of the user rnat value.
240  *
241  * Boundary cases:
242  *
243  * o when reading the rnat "below" the first rnat slot on the kernel
244  *   backing store, rnat0/rnat1 are set to 0 and the low order bits are
245  *   merged in from pt->ar_rnat.
246  *
247  * o when reading the rnat "above" the last rnat slot on the kernel
248  *   backing store, rnat0/rnat1 gets its value from sw->ar_rnat.
249  */
250 static unsigned long
251 get_rnat (struct task_struct *task, struct switch_stack *sw,
252 	  unsigned long *krbs, unsigned long *urnat_addr,
253 	  unsigned long *urbs_end)
254 {
255 	unsigned long rnat0 = 0, rnat1 = 0, urnat = 0, *slot0_kaddr;
256 	unsigned long umask = 0, mask, m;
257 	unsigned long *kbsp, *ubspstore, *rnat0_kaddr, *rnat1_kaddr, shift;
258 	long num_regs, nbits;
259 	struct pt_regs *pt;
260 
261 	pt = task_pt_regs(task);
262 	kbsp = (unsigned long *) sw->ar_bspstore;
263 	ubspstore = (unsigned long *) pt->ar_bspstore;
264 
265 	if (urbs_end < urnat_addr)
266 		nbits = ia64_rse_num_regs(urnat_addr - 63, urbs_end);
267 	else
268 		nbits = 63;
269 	mask = MASK(nbits);
270 	/*
271 	 * First, figure out which bit number slot 0 in user-land maps
272 	 * to in the kernel rnat.  Do this by figuring out how many
273 	 * register slots we're beyond the user's backingstore and
274 	 * then computing the equivalent address in kernel space.
275 	 */
276 	num_regs = ia64_rse_num_regs(ubspstore, urnat_addr + 1);
277 	slot0_kaddr = ia64_rse_skip_regs(krbs, num_regs);
278 	shift = ia64_rse_slot_num(slot0_kaddr);
279 	rnat1_kaddr = ia64_rse_rnat_addr(slot0_kaddr);
280 	rnat0_kaddr = rnat1_kaddr - 64;
281 
282 	if (ubspstore + 63 > urnat_addr) {
283 		/* some bits need to be merged in from pt->ar_rnat */
284 		umask = MASK(ia64_rse_slot_num(ubspstore)) & mask;
285 		urnat = (pt->ar_rnat & umask);
286 		mask &= ~umask;
287 		if (!mask)
288 			return urnat;
289 	}
290 
291 	m = mask << shift;
292 	if (rnat0_kaddr >= kbsp)
293 		rnat0 = sw->ar_rnat;
294 	else if (rnat0_kaddr > krbs)
295 		rnat0 = *rnat0_kaddr;
296 	urnat |= (rnat0 & m) >> shift;
297 
298 	m = mask >> (63 - shift);
299 	if (rnat1_kaddr >= kbsp)
300 		rnat1 = sw->ar_rnat;
301 	else if (rnat1_kaddr > krbs)
302 		rnat1 = *rnat1_kaddr;
303 	urnat |= (rnat1 & m) << (63 - shift);
304 	return urnat;
305 }
306 
307 /*
308  * The reverse of get_rnat.
309  */
310 static void
311 put_rnat (struct task_struct *task, struct switch_stack *sw,
312 	  unsigned long *krbs, unsigned long *urnat_addr, unsigned long urnat,
313 	  unsigned long *urbs_end)
314 {
315 	unsigned long rnat0 = 0, rnat1 = 0, *slot0_kaddr, umask = 0, mask, m;
316 	unsigned long *kbsp, *ubspstore, *rnat0_kaddr, *rnat1_kaddr, shift;
317 	long num_regs, nbits;
318 	struct pt_regs *pt;
319 	unsigned long cfm, *urbs_kargs;
320 
321 	pt = task_pt_regs(task);
322 	kbsp = (unsigned long *) sw->ar_bspstore;
323 	ubspstore = (unsigned long *) pt->ar_bspstore;
324 
325 	urbs_kargs = urbs_end;
326 	if (in_syscall(pt)) {
327 		/*
328 		 * If entered via syscall, don't allow user to set rnat bits
329 		 * for syscall args.
330 		 */
331 		cfm = pt->cr_ifs;
332 		urbs_kargs = ia64_rse_skip_regs(urbs_end, -(cfm & 0x7f));
333 	}
334 
335 	if (urbs_kargs >= urnat_addr)
336 		nbits = 63;
337 	else {
338 		if ((urnat_addr - 63) >= urbs_kargs)
339 			return;
340 		nbits = ia64_rse_num_regs(urnat_addr - 63, urbs_kargs);
341 	}
342 	mask = MASK(nbits);
343 
344 	/*
345 	 * First, figure out which bit number slot 0 in user-land maps
346 	 * to in the kernel rnat.  Do this by figuring out how many
347 	 * register slots we're beyond the user's backingstore and
348 	 * then computing the equivalent address in kernel space.
349 	 */
350 	num_regs = ia64_rse_num_regs(ubspstore, urnat_addr + 1);
351 	slot0_kaddr = ia64_rse_skip_regs(krbs, num_regs);
352 	shift = ia64_rse_slot_num(slot0_kaddr);
353 	rnat1_kaddr = ia64_rse_rnat_addr(slot0_kaddr);
354 	rnat0_kaddr = rnat1_kaddr - 64;
355 
356 	if (ubspstore + 63 > urnat_addr) {
357 		/* some bits need to be place in pt->ar_rnat: */
358 		umask = MASK(ia64_rse_slot_num(ubspstore)) & mask;
359 		pt->ar_rnat = (pt->ar_rnat & ~umask) | (urnat & umask);
360 		mask &= ~umask;
361 		if (!mask)
362 			return;
363 	}
364 	/*
365 	 * Note: Section 11.1 of the EAS guarantees that bit 63 of an
366 	 * rnat slot is ignored. so we don't have to clear it here.
367 	 */
368 	rnat0 = (urnat << shift);
369 	m = mask << shift;
370 	if (rnat0_kaddr >= kbsp)
371 		sw->ar_rnat = (sw->ar_rnat & ~m) | (rnat0 & m);
372 	else if (rnat0_kaddr > krbs)
373 		*rnat0_kaddr = ((*rnat0_kaddr & ~m) | (rnat0 & m));
374 
375 	rnat1 = (urnat >> (63 - shift));
376 	m = mask >> (63 - shift);
377 	if (rnat1_kaddr >= kbsp)
378 		sw->ar_rnat = (sw->ar_rnat & ~m) | (rnat1 & m);
379 	else if (rnat1_kaddr > krbs)
380 		*rnat1_kaddr = ((*rnat1_kaddr & ~m) | (rnat1 & m));
381 }
382 
383 static inline int
384 on_kernel_rbs (unsigned long addr, unsigned long bspstore,
385 	       unsigned long urbs_end)
386 {
387 	unsigned long *rnat_addr = ia64_rse_rnat_addr((unsigned long *)
388 						      urbs_end);
389 	return (addr >= bspstore && addr <= (unsigned long) rnat_addr);
390 }
391 
392 /*
393  * Read a word from the user-level backing store of task CHILD.  ADDR
394  * is the user-level address to read the word from, VAL a pointer to
395  * the return value, and USER_BSP gives the end of the user-level
396  * backing store (i.e., it's the address that would be in ar.bsp after
397  * the user executed a "cover" instruction).
398  *
399  * This routine takes care of accessing the kernel register backing
400  * store for those registers that got spilled there.  It also takes
401  * care of calculating the appropriate RNaT collection words.
402  */
403 long
404 ia64_peek (struct task_struct *child, struct switch_stack *child_stack,
405 	   unsigned long user_rbs_end, unsigned long addr, long *val)
406 {
407 	unsigned long *bspstore, *krbs, regnum, *laddr, *urbs_end, *rnat_addr;
408 	struct pt_regs *child_regs;
409 	size_t copied;
410 	long ret;
411 
412 	urbs_end = (long *) user_rbs_end;
413 	laddr = (unsigned long *) addr;
414 	child_regs = task_pt_regs(child);
415 	bspstore = (unsigned long *) child_regs->ar_bspstore;
416 	krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
417 	if (on_kernel_rbs(addr, (unsigned long) bspstore,
418 			  (unsigned long) urbs_end))
419 	{
420 		/*
421 		 * Attempt to read the RBS in an area that's actually
422 		 * on the kernel RBS => read the corresponding bits in
423 		 * the kernel RBS.
424 		 */
425 		rnat_addr = ia64_rse_rnat_addr(laddr);
426 		ret = get_rnat(child, child_stack, krbs, rnat_addr, urbs_end);
427 
428 		if (laddr == rnat_addr) {
429 			/* return NaT collection word itself */
430 			*val = ret;
431 			return 0;
432 		}
433 
434 		if (((1UL << ia64_rse_slot_num(laddr)) & ret) != 0) {
435 			/*
436 			 * It is implementation dependent whether the
437 			 * data portion of a NaT value gets saved on a
438 			 * st8.spill or RSE spill (e.g., see EAS 2.6,
439 			 * 4.4.4.6 Register Spill and Fill).  To get
440 			 * consistent behavior across all possible
441 			 * IA-64 implementations, we return zero in
442 			 * this case.
443 			 */
444 			*val = 0;
445 			return 0;
446 		}
447 
448 		if (laddr < urbs_end) {
449 			/*
450 			 * The desired word is on the kernel RBS and
451 			 * is not a NaT.
452 			 */
453 			regnum = ia64_rse_num_regs(bspstore, laddr);
454 			*val = *ia64_rse_skip_regs(krbs, regnum);
455 			return 0;
456 		}
457 	}
458 	copied = access_process_vm(child, addr, &ret, sizeof(ret), FOLL_FORCE);
459 	if (copied != sizeof(ret))
460 		return -EIO;
461 	*val = ret;
462 	return 0;
463 }
464 
465 long
466 ia64_poke (struct task_struct *child, struct switch_stack *child_stack,
467 	   unsigned long user_rbs_end, unsigned long addr, long val)
468 {
469 	unsigned long *bspstore, *krbs, regnum, *laddr;
470 	unsigned long *urbs_end = (long *) user_rbs_end;
471 	struct pt_regs *child_regs;
472 
473 	laddr = (unsigned long *) addr;
474 	child_regs = task_pt_regs(child);
475 	bspstore = (unsigned long *) child_regs->ar_bspstore;
476 	krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
477 	if (on_kernel_rbs(addr, (unsigned long) bspstore,
478 			  (unsigned long) urbs_end))
479 	{
480 		/*
481 		 * Attempt to write the RBS in an area that's actually
482 		 * on the kernel RBS => write the corresponding bits
483 		 * in the kernel RBS.
484 		 */
485 		if (ia64_rse_is_rnat_slot(laddr))
486 			put_rnat(child, child_stack, krbs, laddr, val,
487 				 urbs_end);
488 		else {
489 			if (laddr < urbs_end) {
490 				regnum = ia64_rse_num_regs(bspstore, laddr);
491 				*ia64_rse_skip_regs(krbs, regnum) = val;
492 			}
493 		}
494 	} else if (access_process_vm(child, addr, &val, sizeof(val),
495 				FOLL_FORCE | FOLL_WRITE)
496 		   != sizeof(val))
497 		return -EIO;
498 	return 0;
499 }
500 
501 /*
502  * Calculate the address of the end of the user-level register backing
503  * store.  This is the address that would have been stored in ar.bsp
504  * if the user had executed a "cover" instruction right before
505  * entering the kernel.  If CFMP is not NULL, it is used to return the
506  * "current frame mask" that was active at the time the kernel was
507  * entered.
508  */
509 unsigned long
510 ia64_get_user_rbs_end (struct task_struct *child, struct pt_regs *pt,
511 		       unsigned long *cfmp)
512 {
513 	unsigned long *krbs, *bspstore, cfm = pt->cr_ifs;
514 	long ndirty;
515 
516 	krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
517 	bspstore = (unsigned long *) pt->ar_bspstore;
518 	ndirty = ia64_rse_num_regs(krbs, krbs + (pt->loadrs >> 19));
519 
520 	if (in_syscall(pt))
521 		ndirty += (cfm & 0x7f);
522 	else
523 		cfm &= ~(1UL << 63);	/* clear valid bit */
524 
525 	if (cfmp)
526 		*cfmp = cfm;
527 	return (unsigned long) ia64_rse_skip_regs(bspstore, ndirty);
528 }
529 
530 /*
531  * Synchronize (i.e, write) the RSE backing store living in kernel
532  * space to the VM of the CHILD task.  SW and PT are the pointers to
533  * the switch_stack and pt_regs structures, respectively.
534  * USER_RBS_END is the user-level address at which the backing store
535  * ends.
536  */
537 long
538 ia64_sync_user_rbs (struct task_struct *child, struct switch_stack *sw,
539 		    unsigned long user_rbs_start, unsigned long user_rbs_end)
540 {
541 	unsigned long addr, val;
542 	long ret;
543 
544 	/* now copy word for word from kernel rbs to user rbs: */
545 	for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) {
546 		ret = ia64_peek(child, sw, user_rbs_end, addr, &val);
547 		if (ret < 0)
548 			return ret;
549 		if (access_process_vm(child, addr, &val, sizeof(val),
550 				FOLL_FORCE | FOLL_WRITE)
551 		    != sizeof(val))
552 			return -EIO;
553 	}
554 	return 0;
555 }
556 
557 static long
558 ia64_sync_kernel_rbs (struct task_struct *child, struct switch_stack *sw,
559 		unsigned long user_rbs_start, unsigned long user_rbs_end)
560 {
561 	unsigned long addr, val;
562 	long ret;
563 
564 	/* now copy word for word from user rbs to kernel rbs: */
565 	for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) {
566 		if (access_process_vm(child, addr, &val, sizeof(val),
567 				FOLL_FORCE)
568 				!= sizeof(val))
569 			return -EIO;
570 
571 		ret = ia64_poke(child, sw, user_rbs_end, addr, val);
572 		if (ret < 0)
573 			return ret;
574 	}
575 	return 0;
576 }
577 
578 typedef long (*syncfunc_t)(struct task_struct *, struct switch_stack *,
579 			    unsigned long, unsigned long);
580 
581 static void do_sync_rbs(struct unw_frame_info *info, void *arg)
582 {
583 	struct pt_regs *pt;
584 	unsigned long urbs_end;
585 	syncfunc_t fn = arg;
586 
587 	if (unw_unwind_to_user(info) < 0)
588 		return;
589 	pt = task_pt_regs(info->task);
590 	urbs_end = ia64_get_user_rbs_end(info->task, pt, NULL);
591 
592 	fn(info->task, info->sw, pt->ar_bspstore, urbs_end);
593 }
594 
595 /*
596  * when a thread is stopped (ptraced), debugger might change thread's user
597  * stack (change memory directly), and we must avoid the RSE stored in kernel
598  * to override user stack (user space's RSE is newer than kernel's in the
599  * case). To workaround the issue, we copy kernel RSE to user RSE before the
600  * task is stopped, so user RSE has updated data.  we then copy user RSE to
601  * kernel after the task is resummed from traced stop and kernel will use the
602  * newer RSE to return to user. TIF_RESTORE_RSE is the flag to indicate we need
603  * synchronize user RSE to kernel.
604  */
605 void ia64_ptrace_stop(void)
606 {
607 	if (test_and_set_tsk_thread_flag(current, TIF_RESTORE_RSE))
608 		return;
609 	set_notify_resume(current);
610 	unw_init_running(do_sync_rbs, ia64_sync_user_rbs);
611 }
612 
613 /*
614  * This is called to read back the register backing store.
615  */
616 void ia64_sync_krbs(void)
617 {
618 	clear_tsk_thread_flag(current, TIF_RESTORE_RSE);
619 
620 	unw_init_running(do_sync_rbs, ia64_sync_kernel_rbs);
621 }
622 
623 /*
624  * After PTRACE_ATTACH, a thread's register backing store area in user
625  * space is assumed to contain correct data whenever the thread is
626  * stopped.  arch_ptrace_stop takes care of this on tracing stops.
627  * But if the child was already stopped for job control when we attach
628  * to it, then it might not ever get into ptrace_stop by the time we
629  * want to examine the user memory containing the RBS.
630  */
631 void
632 ptrace_attach_sync_user_rbs (struct task_struct *child)
633 {
634 	int stopped = 0;
635 	struct unw_frame_info info;
636 
637 	/*
638 	 * If the child is in TASK_STOPPED, we need to change that to
639 	 * TASK_TRACED momentarily while we operate on it.  This ensures
640 	 * that the child won't be woken up and return to user mode while
641 	 * we are doing the sync.  (It can only be woken up for SIGKILL.)
642 	 */
643 
644 	read_lock(&tasklist_lock);
645 	if (child->sighand) {
646 		spin_lock_irq(&child->sighand->siglock);
647 		if (child->state == TASK_STOPPED &&
648 		    !test_and_set_tsk_thread_flag(child, TIF_RESTORE_RSE)) {
649 			set_notify_resume(child);
650 
651 			child->state = TASK_TRACED;
652 			stopped = 1;
653 		}
654 		spin_unlock_irq(&child->sighand->siglock);
655 	}
656 	read_unlock(&tasklist_lock);
657 
658 	if (!stopped)
659 		return;
660 
661 	unw_init_from_blocked_task(&info, child);
662 	do_sync_rbs(&info, ia64_sync_user_rbs);
663 
664 	/*
665 	 * Now move the child back into TASK_STOPPED if it should be in a
666 	 * job control stop, so that SIGCONT can be used to wake it up.
667 	 */
668 	read_lock(&tasklist_lock);
669 	if (child->sighand) {
670 		spin_lock_irq(&child->sighand->siglock);
671 		if (child->state == TASK_TRACED &&
672 		    (child->signal->flags & SIGNAL_STOP_STOPPED)) {
673 			child->state = TASK_STOPPED;
674 		}
675 		spin_unlock_irq(&child->sighand->siglock);
676 	}
677 	read_unlock(&tasklist_lock);
678 }
679 
680 /*
681  * Write f32-f127 back to task->thread.fph if it has been modified.
682  */
683 inline void
684 ia64_flush_fph (struct task_struct *task)
685 {
686 	struct ia64_psr *psr = ia64_psr(task_pt_regs(task));
687 
688 	/*
689 	 * Prevent migrating this task while
690 	 * we're fiddling with the FPU state
691 	 */
692 	preempt_disable();
693 	if (ia64_is_local_fpu_owner(task) && psr->mfh) {
694 		psr->mfh = 0;
695 		task->thread.flags |= IA64_THREAD_FPH_VALID;
696 		ia64_save_fpu(&task->thread.fph[0]);
697 	}
698 	preempt_enable();
699 }
700 
701 /*
702  * Sync the fph state of the task so that it can be manipulated
703  * through thread.fph.  If necessary, f32-f127 are written back to
704  * thread.fph or, if the fph state hasn't been used before, thread.fph
705  * is cleared to zeroes.  Also, access to f32-f127 is disabled to
706  * ensure that the task picks up the state from thread.fph when it
707  * executes again.
708  */
709 void
710 ia64_sync_fph (struct task_struct *task)
711 {
712 	struct ia64_psr *psr = ia64_psr(task_pt_regs(task));
713 
714 	ia64_flush_fph(task);
715 	if (!(task->thread.flags & IA64_THREAD_FPH_VALID)) {
716 		task->thread.flags |= IA64_THREAD_FPH_VALID;
717 		memset(&task->thread.fph, 0, sizeof(task->thread.fph));
718 	}
719 	ia64_drop_fpu(task);
720 	psr->dfh = 1;
721 }
722 
723 /*
724  * Change the machine-state of CHILD such that it will return via the normal
725  * kernel exit-path, rather than the syscall-exit path.
726  */
727 static void
728 convert_to_non_syscall (struct task_struct *child, struct pt_regs  *pt,
729 			unsigned long cfm)
730 {
731 	struct unw_frame_info info, prev_info;
732 	unsigned long ip, sp, pr;
733 
734 	unw_init_from_blocked_task(&info, child);
735 	while (1) {
736 		prev_info = info;
737 		if (unw_unwind(&info) < 0)
738 			return;
739 
740 		unw_get_sp(&info, &sp);
741 		if ((long)((unsigned long)child + IA64_STK_OFFSET - sp)
742 		    < IA64_PT_REGS_SIZE) {
743 			dprintk("ptrace.%s: ran off the top of the kernel "
744 				"stack\n", __func__);
745 			return;
746 		}
747 		if (unw_get_pr (&prev_info, &pr) < 0) {
748 			unw_get_rp(&prev_info, &ip);
749 			dprintk("ptrace.%s: failed to read "
750 				"predicate register (ip=0x%lx)\n",
751 				__func__, ip);
752 			return;
753 		}
754 		if (unw_is_intr_frame(&info)
755 		    && (pr & (1UL << PRED_USER_STACK)))
756 			break;
757 	}
758 
759 	/*
760 	 * Note: at the time of this call, the target task is blocked
761 	 * in notify_resume_user() and by clearling PRED_LEAVE_SYSCALL
762 	 * (aka, "pLvSys") we redirect execution from
763 	 * .work_pending_syscall_end to .work_processed_kernel.
764 	 */
765 	unw_get_pr(&prev_info, &pr);
766 	pr &= ~((1UL << PRED_SYSCALL) | (1UL << PRED_LEAVE_SYSCALL));
767 	pr |=  (1UL << PRED_NON_SYSCALL);
768 	unw_set_pr(&prev_info, pr);
769 
770 	pt->cr_ifs = (1UL << 63) | cfm;
771 	/*
772 	 * Clear the memory that is NOT written on syscall-entry to
773 	 * ensure we do not leak kernel-state to user when execution
774 	 * resumes.
775 	 */
776 	pt->r2 = 0;
777 	pt->r3 = 0;
778 	pt->r14 = 0;
779 	memset(&pt->r16, 0, 16*8);	/* clear r16-r31 */
780 	memset(&pt->f6, 0, 6*16);	/* clear f6-f11 */
781 	pt->b7 = 0;
782 	pt->ar_ccv = 0;
783 	pt->ar_csd = 0;
784 	pt->ar_ssd = 0;
785 }
786 
787 static int
788 access_nat_bits (struct task_struct *child, struct pt_regs *pt,
789 		 struct unw_frame_info *info,
790 		 unsigned long *data, int write_access)
791 {
792 	unsigned long regnum, nat_bits, scratch_unat, dummy = 0;
793 	char nat = 0;
794 
795 	if (write_access) {
796 		nat_bits = *data;
797 		scratch_unat = ia64_put_scratch_nat_bits(pt, nat_bits);
798 		if (unw_set_ar(info, UNW_AR_UNAT, scratch_unat) < 0) {
799 			dprintk("ptrace: failed to set ar.unat\n");
800 			return -1;
801 		}
802 		for (regnum = 4; regnum <= 7; ++regnum) {
803 			unw_get_gr(info, regnum, &dummy, &nat);
804 			unw_set_gr(info, regnum, dummy,
805 				   (nat_bits >> regnum) & 1);
806 		}
807 	} else {
808 		if (unw_get_ar(info, UNW_AR_UNAT, &scratch_unat) < 0) {
809 			dprintk("ptrace: failed to read ar.unat\n");
810 			return -1;
811 		}
812 		nat_bits = ia64_get_scratch_nat_bits(pt, scratch_unat);
813 		for (regnum = 4; regnum <= 7; ++regnum) {
814 			unw_get_gr(info, regnum, &dummy, &nat);
815 			nat_bits |= (nat != 0) << regnum;
816 		}
817 		*data = nat_bits;
818 	}
819 	return 0;
820 }
821 
822 static int
823 access_uarea (struct task_struct *child, unsigned long addr,
824 	      unsigned long *data, int write_access);
825 
826 static long
827 ptrace_getregs (struct task_struct *child, struct pt_all_user_regs __user *ppr)
828 {
829 	unsigned long psr, ec, lc, rnat, bsp, cfm, nat_bits, val;
830 	struct unw_frame_info info;
831 	struct ia64_fpreg fpval;
832 	struct switch_stack *sw;
833 	struct pt_regs *pt;
834 	long ret, retval = 0;
835 	char nat = 0;
836 	int i;
837 
838 	if (!access_ok(VERIFY_WRITE, ppr, sizeof(struct pt_all_user_regs)))
839 		return -EIO;
840 
841 	pt = task_pt_regs(child);
842 	sw = (struct switch_stack *) (child->thread.ksp + 16);
843 	unw_init_from_blocked_task(&info, child);
844 	if (unw_unwind_to_user(&info) < 0) {
845 		return -EIO;
846 	}
847 
848 	if (((unsigned long) ppr & 0x7) != 0) {
849 		dprintk("ptrace:unaligned register address %p\n", ppr);
850 		return -EIO;
851 	}
852 
853 	if (access_uarea(child, PT_CR_IPSR, &psr, 0) < 0
854 	    || access_uarea(child, PT_AR_EC, &ec, 0) < 0
855 	    || access_uarea(child, PT_AR_LC, &lc, 0) < 0
856 	    || access_uarea(child, PT_AR_RNAT, &rnat, 0) < 0
857 	    || access_uarea(child, PT_AR_BSP, &bsp, 0) < 0
858 	    || access_uarea(child, PT_CFM, &cfm, 0)
859 	    || access_uarea(child, PT_NAT_BITS, &nat_bits, 0))
860 		return -EIO;
861 
862 	/* control regs */
863 
864 	retval |= __put_user(pt->cr_iip, &ppr->cr_iip);
865 	retval |= __put_user(psr, &ppr->cr_ipsr);
866 
867 	/* app regs */
868 
869 	retval |= __put_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
870 	retval |= __put_user(pt->ar_rsc, &ppr->ar[PT_AUR_RSC]);
871 	retval |= __put_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
872 	retval |= __put_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
873 	retval |= __put_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
874 	retval |= __put_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);
875 
876 	retval |= __put_user(ec, &ppr->ar[PT_AUR_EC]);
877 	retval |= __put_user(lc, &ppr->ar[PT_AUR_LC]);
878 	retval |= __put_user(rnat, &ppr->ar[PT_AUR_RNAT]);
879 	retval |= __put_user(bsp, &ppr->ar[PT_AUR_BSP]);
880 	retval |= __put_user(cfm, &ppr->cfm);
881 
882 	/* gr1-gr3 */
883 
884 	retval |= __copy_to_user(&ppr->gr[1], &pt->r1, sizeof(long));
885 	retval |= __copy_to_user(&ppr->gr[2], &pt->r2, sizeof(long) *2);
886 
887 	/* gr4-gr7 */
888 
889 	for (i = 4; i < 8; i++) {
890 		if (unw_access_gr(&info, i, &val, &nat, 0) < 0)
891 			return -EIO;
892 		retval |= __put_user(val, &ppr->gr[i]);
893 	}
894 
895 	/* gr8-gr11 */
896 
897 	retval |= __copy_to_user(&ppr->gr[8], &pt->r8, sizeof(long) * 4);
898 
899 	/* gr12-gr15 */
900 
901 	retval |= __copy_to_user(&ppr->gr[12], &pt->r12, sizeof(long) * 2);
902 	retval |= __copy_to_user(&ppr->gr[14], &pt->r14, sizeof(long));
903 	retval |= __copy_to_user(&ppr->gr[15], &pt->r15, sizeof(long));
904 
905 	/* gr16-gr31 */
906 
907 	retval |= __copy_to_user(&ppr->gr[16], &pt->r16, sizeof(long) * 16);
908 
909 	/* b0 */
910 
911 	retval |= __put_user(pt->b0, &ppr->br[0]);
912 
913 	/* b1-b5 */
914 
915 	for (i = 1; i < 6; i++) {
916 		if (unw_access_br(&info, i, &val, 0) < 0)
917 			return -EIO;
918 		__put_user(val, &ppr->br[i]);
919 	}
920 
921 	/* b6-b7 */
922 
923 	retval |= __put_user(pt->b6, &ppr->br[6]);
924 	retval |= __put_user(pt->b7, &ppr->br[7]);
925 
926 	/* fr2-fr5 */
927 
928 	for (i = 2; i < 6; i++) {
929 		if (unw_get_fr(&info, i, &fpval) < 0)
930 			return -EIO;
931 		retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
932 	}
933 
934 	/* fr6-fr11 */
935 
936 	retval |= __copy_to_user(&ppr->fr[6], &pt->f6,
937 				 sizeof(struct ia64_fpreg) * 6);
938 
939 	/* fp scratch regs(12-15) */
940 
941 	retval |= __copy_to_user(&ppr->fr[12], &sw->f12,
942 				 sizeof(struct ia64_fpreg) * 4);
943 
944 	/* fr16-fr31 */
945 
946 	for (i = 16; i < 32; i++) {
947 		if (unw_get_fr(&info, i, &fpval) < 0)
948 			return -EIO;
949 		retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
950 	}
951 
952 	/* fph */
953 
954 	ia64_flush_fph(child);
955 	retval |= __copy_to_user(&ppr->fr[32], &child->thread.fph,
956 				 sizeof(ppr->fr[32]) * 96);
957 
958 	/*  preds */
959 
960 	retval |= __put_user(pt->pr, &ppr->pr);
961 
962 	/* nat bits */
963 
964 	retval |= __put_user(nat_bits, &ppr->nat);
965 
966 	ret = retval ? -EIO : 0;
967 	return ret;
968 }
969 
970 static long
971 ptrace_setregs (struct task_struct *child, struct pt_all_user_regs __user *ppr)
972 {
973 	unsigned long psr, rsc, ec, lc, rnat, bsp, cfm, nat_bits, val = 0;
974 	struct unw_frame_info info;
975 	struct switch_stack *sw;
976 	struct ia64_fpreg fpval;
977 	struct pt_regs *pt;
978 	long ret, retval = 0;
979 	int i;
980 
981 	memset(&fpval, 0, sizeof(fpval));
982 
983 	if (!access_ok(VERIFY_READ, ppr, sizeof(struct pt_all_user_regs)))
984 		return -EIO;
985 
986 	pt = task_pt_regs(child);
987 	sw = (struct switch_stack *) (child->thread.ksp + 16);
988 	unw_init_from_blocked_task(&info, child);
989 	if (unw_unwind_to_user(&info) < 0) {
990 		return -EIO;
991 	}
992 
993 	if (((unsigned long) ppr & 0x7) != 0) {
994 		dprintk("ptrace:unaligned register address %p\n", ppr);
995 		return -EIO;
996 	}
997 
998 	/* control regs */
999 
1000 	retval |= __get_user(pt->cr_iip, &ppr->cr_iip);
1001 	retval |= __get_user(psr, &ppr->cr_ipsr);
1002 
1003 	/* app regs */
1004 
1005 	retval |= __get_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
1006 	retval |= __get_user(rsc, &ppr->ar[PT_AUR_RSC]);
1007 	retval |= __get_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
1008 	retval |= __get_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
1009 	retval |= __get_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
1010 	retval |= __get_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);
1011 
1012 	retval |= __get_user(ec, &ppr->ar[PT_AUR_EC]);
1013 	retval |= __get_user(lc, &ppr->ar[PT_AUR_LC]);
1014 	retval |= __get_user(rnat, &ppr->ar[PT_AUR_RNAT]);
1015 	retval |= __get_user(bsp, &ppr->ar[PT_AUR_BSP]);
1016 	retval |= __get_user(cfm, &ppr->cfm);
1017 
1018 	/* gr1-gr3 */
1019 
1020 	retval |= __copy_from_user(&pt->r1, &ppr->gr[1], sizeof(long));
1021 	retval |= __copy_from_user(&pt->r2, &ppr->gr[2], sizeof(long) * 2);
1022 
1023 	/* gr4-gr7 */
1024 
1025 	for (i = 4; i < 8; i++) {
1026 		retval |= __get_user(val, &ppr->gr[i]);
1027 		/* NaT bit will be set via PT_NAT_BITS: */
1028 		if (unw_set_gr(&info, i, val, 0) < 0)
1029 			return -EIO;
1030 	}
1031 
1032 	/* gr8-gr11 */
1033 
1034 	retval |= __copy_from_user(&pt->r8, &ppr->gr[8], sizeof(long) * 4);
1035 
1036 	/* gr12-gr15 */
1037 
1038 	retval |= __copy_from_user(&pt->r12, &ppr->gr[12], sizeof(long) * 2);
1039 	retval |= __copy_from_user(&pt->r14, &ppr->gr[14], sizeof(long));
1040 	retval |= __copy_from_user(&pt->r15, &ppr->gr[15], sizeof(long));
1041 
1042 	/* gr16-gr31 */
1043 
1044 	retval |= __copy_from_user(&pt->r16, &ppr->gr[16], sizeof(long) * 16);
1045 
1046 	/* b0 */
1047 
1048 	retval |= __get_user(pt->b0, &ppr->br[0]);
1049 
1050 	/* b1-b5 */
1051 
1052 	for (i = 1; i < 6; i++) {
1053 		retval |= __get_user(val, &ppr->br[i]);
1054 		unw_set_br(&info, i, val);
1055 	}
1056 
1057 	/* b6-b7 */
1058 
1059 	retval |= __get_user(pt->b6, &ppr->br[6]);
1060 	retval |= __get_user(pt->b7, &ppr->br[7]);
1061 
1062 	/* fr2-fr5 */
1063 
1064 	for (i = 2; i < 6; i++) {
1065 		retval |= __copy_from_user(&fpval, &ppr->fr[i], sizeof(fpval));
1066 		if (unw_set_fr(&info, i, fpval) < 0)
1067 			return -EIO;
1068 	}
1069 
1070 	/* fr6-fr11 */
1071 
1072 	retval |= __copy_from_user(&pt->f6, &ppr->fr[6],
1073 				   sizeof(ppr->fr[6]) * 6);
1074 
1075 	/* fp scratch regs(12-15) */
1076 
1077 	retval |= __copy_from_user(&sw->f12, &ppr->fr[12],
1078 				   sizeof(ppr->fr[12]) * 4);
1079 
1080 	/* fr16-fr31 */
1081 
1082 	for (i = 16; i < 32; i++) {
1083 		retval |= __copy_from_user(&fpval, &ppr->fr[i],
1084 					   sizeof(fpval));
1085 		if (unw_set_fr(&info, i, fpval) < 0)
1086 			return -EIO;
1087 	}
1088 
1089 	/* fph */
1090 
1091 	ia64_sync_fph(child);
1092 	retval |= __copy_from_user(&child->thread.fph, &ppr->fr[32],
1093 				   sizeof(ppr->fr[32]) * 96);
1094 
1095 	/* preds */
1096 
1097 	retval |= __get_user(pt->pr, &ppr->pr);
1098 
1099 	/* nat bits */
1100 
1101 	retval |= __get_user(nat_bits, &ppr->nat);
1102 
1103 	retval |= access_uarea(child, PT_CR_IPSR, &psr, 1);
1104 	retval |= access_uarea(child, PT_AR_RSC, &rsc, 1);
1105 	retval |= access_uarea(child, PT_AR_EC, &ec, 1);
1106 	retval |= access_uarea(child, PT_AR_LC, &lc, 1);
1107 	retval |= access_uarea(child, PT_AR_RNAT, &rnat, 1);
1108 	retval |= access_uarea(child, PT_AR_BSP, &bsp, 1);
1109 	retval |= access_uarea(child, PT_CFM, &cfm, 1);
1110 	retval |= access_uarea(child, PT_NAT_BITS, &nat_bits, 1);
1111 
1112 	ret = retval ? -EIO : 0;
1113 	return ret;
1114 }
1115 
1116 void
1117 user_enable_single_step (struct task_struct *child)
1118 {
1119 	struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
1120 
1121 	set_tsk_thread_flag(child, TIF_SINGLESTEP);
1122 	child_psr->ss = 1;
1123 }
1124 
1125 void
1126 user_enable_block_step (struct task_struct *child)
1127 {
1128 	struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
1129 
1130 	set_tsk_thread_flag(child, TIF_SINGLESTEP);
1131 	child_psr->tb = 1;
1132 }
1133 
1134 void
1135 user_disable_single_step (struct task_struct *child)
1136 {
1137 	struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
1138 
1139 	/* make sure the single step/taken-branch trap bits are not set: */
1140 	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
1141 	child_psr->ss = 0;
1142 	child_psr->tb = 0;
1143 }
1144 
1145 /*
1146  * Called by kernel/ptrace.c when detaching..
1147  *
1148  * Make sure the single step bit is not set.
1149  */
1150 void
1151 ptrace_disable (struct task_struct *child)
1152 {
1153 	user_disable_single_step(child);
1154 }
1155 
1156 long
1157 arch_ptrace (struct task_struct *child, long request,
1158 	     unsigned long addr, unsigned long data)
1159 {
1160 	switch (request) {
1161 	case PTRACE_PEEKTEXT:
1162 	case PTRACE_PEEKDATA:
1163 		/* read word at location addr */
1164 		if (ptrace_access_vm(child, addr, &data, sizeof(data),
1165 				FOLL_FORCE)
1166 		    != sizeof(data))
1167 			return -EIO;
1168 		/* ensure return value is not mistaken for error code */
1169 		force_successful_syscall_return();
1170 		return data;
1171 
1172 	/* PTRACE_POKETEXT and PTRACE_POKEDATA is handled
1173 	 * by the generic ptrace_request().
1174 	 */
1175 
1176 	case PTRACE_PEEKUSR:
1177 		/* read the word at addr in the USER area */
1178 		if (access_uarea(child, addr, &data, 0) < 0)
1179 			return -EIO;
1180 		/* ensure return value is not mistaken for error code */
1181 		force_successful_syscall_return();
1182 		return data;
1183 
1184 	case PTRACE_POKEUSR:
1185 		/* write the word at addr in the USER area */
1186 		if (access_uarea(child, addr, &data, 1) < 0)
1187 			return -EIO;
1188 		return 0;
1189 
1190 	case PTRACE_OLD_GETSIGINFO:
1191 		/* for backwards-compatibility */
1192 		return ptrace_request(child, PTRACE_GETSIGINFO, addr, data);
1193 
1194 	case PTRACE_OLD_SETSIGINFO:
1195 		/* for backwards-compatibility */
1196 		return ptrace_request(child, PTRACE_SETSIGINFO, addr, data);
1197 
1198 	case PTRACE_GETREGS:
1199 		return ptrace_getregs(child,
1200 				      (struct pt_all_user_regs __user *) data);
1201 
1202 	case PTRACE_SETREGS:
1203 		return ptrace_setregs(child,
1204 				      (struct pt_all_user_regs __user *) data);
1205 
1206 	default:
1207 		return ptrace_request(child, request, addr, data);
1208 	}
1209 }
1210 
1211 
1212 /* "asmlinkage" so the input arguments are preserved... */
1213 
1214 asmlinkage long
1215 syscall_trace_enter (long arg0, long arg1, long arg2, long arg3,
1216 		     long arg4, long arg5, long arg6, long arg7,
1217 		     struct pt_regs regs)
1218 {
1219 	if (test_thread_flag(TIF_SYSCALL_TRACE))
1220 		if (tracehook_report_syscall_entry(&regs))
1221 			return -ENOSYS;
1222 
1223 	/* copy user rbs to kernel rbs */
1224 	if (test_thread_flag(TIF_RESTORE_RSE))
1225 		ia64_sync_krbs();
1226 
1227 
1228 	audit_syscall_entry(regs.r15, arg0, arg1, arg2, arg3);
1229 
1230 	return 0;
1231 }
1232 
1233 /* "asmlinkage" so the input arguments are preserved... */
1234 
1235 asmlinkage void
1236 syscall_trace_leave (long arg0, long arg1, long arg2, long arg3,
1237 		     long arg4, long arg5, long arg6, long arg7,
1238 		     struct pt_regs regs)
1239 {
1240 	int step;
1241 
1242 	audit_syscall_exit(&regs);
1243 
1244 	step = test_thread_flag(TIF_SINGLESTEP);
1245 	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1246 		tracehook_report_syscall_exit(&regs, step);
1247 
1248 	/* copy user rbs to kernel rbs */
1249 	if (test_thread_flag(TIF_RESTORE_RSE))
1250 		ia64_sync_krbs();
1251 }
1252 
1253 /* Utrace implementation starts here */
1254 struct regset_get {
1255 	void *kbuf;
1256 	void __user *ubuf;
1257 };
1258 
1259 struct regset_set {
1260 	const void *kbuf;
1261 	const void __user *ubuf;
1262 };
1263 
1264 struct regset_getset {
1265 	struct task_struct *target;
1266 	const struct user_regset *regset;
1267 	union {
1268 		struct regset_get get;
1269 		struct regset_set set;
1270 	} u;
1271 	unsigned int pos;
1272 	unsigned int count;
1273 	int ret;
1274 };
1275 
1276 static int
1277 access_elf_gpreg(struct task_struct *target, struct unw_frame_info *info,
1278 		unsigned long addr, unsigned long *data, int write_access)
1279 {
1280 	struct pt_regs *pt;
1281 	unsigned long *ptr = NULL;
1282 	int ret;
1283 	char nat = 0;
1284 
1285 	pt = task_pt_regs(target);
1286 	switch (addr) {
1287 	case ELF_GR_OFFSET(1):
1288 		ptr = &pt->r1;
1289 		break;
1290 	case ELF_GR_OFFSET(2):
1291 	case ELF_GR_OFFSET(3):
1292 		ptr = (void *)&pt->r2 + (addr - ELF_GR_OFFSET(2));
1293 		break;
1294 	case ELF_GR_OFFSET(4) ... ELF_GR_OFFSET(7):
1295 		if (write_access) {
1296 			/* read NaT bit first: */
1297 			unsigned long dummy;
1298 
1299 			ret = unw_get_gr(info, addr/8, &dummy, &nat);
1300 			if (ret < 0)
1301 				return ret;
1302 		}
1303 		return unw_access_gr(info, addr/8, data, &nat, write_access);
1304 	case ELF_GR_OFFSET(8) ... ELF_GR_OFFSET(11):
1305 		ptr = (void *)&pt->r8 + addr - ELF_GR_OFFSET(8);
1306 		break;
1307 	case ELF_GR_OFFSET(12):
1308 	case ELF_GR_OFFSET(13):
1309 		ptr = (void *)&pt->r12 + addr - ELF_GR_OFFSET(12);
1310 		break;
1311 	case ELF_GR_OFFSET(14):
1312 		ptr = &pt->r14;
1313 		break;
1314 	case ELF_GR_OFFSET(15):
1315 		ptr = &pt->r15;
1316 	}
1317 	if (write_access)
1318 		*ptr = *data;
1319 	else
1320 		*data = *ptr;
1321 	return 0;
1322 }
1323 
1324 static int
1325 access_elf_breg(struct task_struct *target, struct unw_frame_info *info,
1326 		unsigned long addr, unsigned long *data, int write_access)
1327 {
1328 	struct pt_regs *pt;
1329 	unsigned long *ptr = NULL;
1330 
1331 	pt = task_pt_regs(target);
1332 	switch (addr) {
1333 	case ELF_BR_OFFSET(0):
1334 		ptr = &pt->b0;
1335 		break;
1336 	case ELF_BR_OFFSET(1) ... ELF_BR_OFFSET(5):
1337 		return unw_access_br(info, (addr - ELF_BR_OFFSET(0))/8,
1338 				     data, write_access);
1339 	case ELF_BR_OFFSET(6):
1340 		ptr = &pt->b6;
1341 		break;
1342 	case ELF_BR_OFFSET(7):
1343 		ptr = &pt->b7;
1344 	}
1345 	if (write_access)
1346 		*ptr = *data;
1347 	else
1348 		*data = *ptr;
1349 	return 0;
1350 }
1351 
1352 static int
1353 access_elf_areg(struct task_struct *target, struct unw_frame_info *info,
1354 		unsigned long addr, unsigned long *data, int write_access)
1355 {
1356 	struct pt_regs *pt;
1357 	unsigned long cfm, urbs_end;
1358 	unsigned long *ptr = NULL;
1359 
1360 	pt = task_pt_regs(target);
1361 	if (addr >= ELF_AR_RSC_OFFSET && addr <= ELF_AR_SSD_OFFSET) {
1362 		switch (addr) {
1363 		case ELF_AR_RSC_OFFSET:
1364 			/* force PL3 */
1365 			if (write_access)
1366 				pt->ar_rsc = *data | (3 << 2);
1367 			else
1368 				*data = pt->ar_rsc;
1369 			return 0;
1370 		case ELF_AR_BSP_OFFSET:
1371 			/*
1372 			 * By convention, we use PT_AR_BSP to refer to
1373 			 * the end of the user-level backing store.
1374 			 * Use ia64_rse_skip_regs(PT_AR_BSP, -CFM.sof)
1375 			 * to get the real value of ar.bsp at the time
1376 			 * the kernel was entered.
1377 			 *
1378 			 * Furthermore, when changing the contents of
1379 			 * PT_AR_BSP (or PT_CFM) while the task is
1380 			 * blocked in a system call, convert the state
1381 			 * so that the non-system-call exit
1382 			 * path is used.  This ensures that the proper
1383 			 * state will be picked up when resuming
1384 			 * execution.  However, it *also* means that
1385 			 * once we write PT_AR_BSP/PT_CFM, it won't be
1386 			 * possible to modify the syscall arguments of
1387 			 * the pending system call any longer.  This
1388 			 * shouldn't be an issue because modifying
1389 			 * PT_AR_BSP/PT_CFM generally implies that
1390 			 * we're either abandoning the pending system
1391 			 * call or that we defer it's re-execution
1392 			 * (e.g., due to GDB doing an inferior
1393 			 * function call).
1394 			 */
1395 			urbs_end = ia64_get_user_rbs_end(target, pt, &cfm);
1396 			if (write_access) {
1397 				if (*data != urbs_end) {
1398 					if (in_syscall(pt))
1399 						convert_to_non_syscall(target,
1400 								       pt,
1401 								       cfm);
1402 					/*
1403 					 * Simulate user-level write
1404 					 * of ar.bsp:
1405 					 */
1406 					pt->loadrs = 0;
1407 					pt->ar_bspstore = *data;
1408 				}
1409 			} else
1410 				*data = urbs_end;
1411 			return 0;
1412 		case ELF_AR_BSPSTORE_OFFSET:
1413 			ptr = &pt->ar_bspstore;
1414 			break;
1415 		case ELF_AR_RNAT_OFFSET:
1416 			ptr = &pt->ar_rnat;
1417 			break;
1418 		case ELF_AR_CCV_OFFSET:
1419 			ptr = &pt->ar_ccv;
1420 			break;
1421 		case ELF_AR_UNAT_OFFSET:
1422 			ptr = &pt->ar_unat;
1423 			break;
1424 		case ELF_AR_FPSR_OFFSET:
1425 			ptr = &pt->ar_fpsr;
1426 			break;
1427 		case ELF_AR_PFS_OFFSET:
1428 			ptr = &pt->ar_pfs;
1429 			break;
1430 		case ELF_AR_LC_OFFSET:
1431 			return unw_access_ar(info, UNW_AR_LC, data,
1432 					     write_access);
1433 		case ELF_AR_EC_OFFSET:
1434 			return unw_access_ar(info, UNW_AR_EC, data,
1435 					     write_access);
1436 		case ELF_AR_CSD_OFFSET:
1437 			ptr = &pt->ar_csd;
1438 			break;
1439 		case ELF_AR_SSD_OFFSET:
1440 			ptr = &pt->ar_ssd;
1441 		}
1442 	} else if (addr >= ELF_CR_IIP_OFFSET && addr <= ELF_CR_IPSR_OFFSET) {
1443 		switch (addr) {
1444 		case ELF_CR_IIP_OFFSET:
1445 			ptr = &pt->cr_iip;
1446 			break;
1447 		case ELF_CFM_OFFSET:
1448 			urbs_end = ia64_get_user_rbs_end(target, pt, &cfm);
1449 			if (write_access) {
1450 				if (((cfm ^ *data) & PFM_MASK) != 0) {
1451 					if (in_syscall(pt))
1452 						convert_to_non_syscall(target,
1453 								       pt,
1454 								       cfm);
1455 					pt->cr_ifs = ((pt->cr_ifs & ~PFM_MASK)
1456 						      | (*data & PFM_MASK));
1457 				}
1458 			} else
1459 				*data = cfm;
1460 			return 0;
1461 		case ELF_CR_IPSR_OFFSET:
1462 			if (write_access) {
1463 				unsigned long tmp = *data;
1464 				/* psr.ri==3 is a reserved value: SDM 2:25 */
1465 				if ((tmp & IA64_PSR_RI) == IA64_PSR_RI)
1466 					tmp &= ~IA64_PSR_RI;
1467 				pt->cr_ipsr = ((tmp & IPSR_MASK)
1468 					       | (pt->cr_ipsr & ~IPSR_MASK));
1469 			} else
1470 				*data = (pt->cr_ipsr & IPSR_MASK);
1471 			return 0;
1472 		}
1473 	} else if (addr == ELF_NAT_OFFSET)
1474 		return access_nat_bits(target, pt, info,
1475 				       data, write_access);
1476 	else if (addr == ELF_PR_OFFSET)
1477 		ptr = &pt->pr;
1478 	else
1479 		return -1;
1480 
1481 	if (write_access)
1482 		*ptr = *data;
1483 	else
1484 		*data = *ptr;
1485 
1486 	return 0;
1487 }
1488 
1489 static int
1490 access_elf_reg(struct task_struct *target, struct unw_frame_info *info,
1491 		unsigned long addr, unsigned long *data, int write_access)
1492 {
1493 	if (addr >= ELF_GR_OFFSET(1) && addr <= ELF_GR_OFFSET(15))
1494 		return access_elf_gpreg(target, info, addr, data, write_access);
1495 	else if (addr >= ELF_BR_OFFSET(0) && addr <= ELF_BR_OFFSET(7))
1496 		return access_elf_breg(target, info, addr, data, write_access);
1497 	else
1498 		return access_elf_areg(target, info, addr, data, write_access);
1499 }
1500 
1501 void do_gpregs_get(struct unw_frame_info *info, void *arg)
1502 {
1503 	struct pt_regs *pt;
1504 	struct regset_getset *dst = arg;
1505 	elf_greg_t tmp[16];
1506 	unsigned int i, index, min_copy;
1507 
1508 	if (unw_unwind_to_user(info) < 0)
1509 		return;
1510 
1511 	/*
1512 	 * coredump format:
1513 	 *      r0-r31
1514 	 *      NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
1515 	 *      predicate registers (p0-p63)
1516 	 *      b0-b7
1517 	 *      ip cfm user-mask
1518 	 *      ar.rsc ar.bsp ar.bspstore ar.rnat
1519 	 *      ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
1520 	 */
1521 
1522 
1523 	/* Skip r0 */
1524 	if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(1)) {
1525 		dst->ret = user_regset_copyout_zero(&dst->pos, &dst->count,
1526 						      &dst->u.get.kbuf,
1527 						      &dst->u.get.ubuf,
1528 						      0, ELF_GR_OFFSET(1));
1529 		if (dst->ret || dst->count == 0)
1530 			return;
1531 	}
1532 
1533 	/* gr1 - gr15 */
1534 	if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(16)) {
1535 		index = (dst->pos - ELF_GR_OFFSET(1)) / sizeof(elf_greg_t);
1536 		min_copy = ELF_GR_OFFSET(16) > (dst->pos + dst->count) ?
1537 			 (dst->pos + dst->count) : ELF_GR_OFFSET(16);
1538 		for (i = dst->pos; i < min_copy; i += sizeof(elf_greg_t),
1539 				index++)
1540 			if (access_elf_reg(dst->target, info, i,
1541 						&tmp[index], 0) < 0) {
1542 				dst->ret = -EIO;
1543 				return;
1544 			}
1545 		dst->ret = user_regset_copyout(&dst->pos, &dst->count,
1546 				&dst->u.get.kbuf, &dst->u.get.ubuf, tmp,
1547 				ELF_GR_OFFSET(1), ELF_GR_OFFSET(16));
1548 		if (dst->ret || dst->count == 0)
1549 			return;
1550 	}
1551 
1552 	/* r16-r31 */
1553 	if (dst->count > 0 && dst->pos < ELF_NAT_OFFSET) {
1554 		pt = task_pt_regs(dst->target);
1555 		dst->ret = user_regset_copyout(&dst->pos, &dst->count,
1556 				&dst->u.get.kbuf, &dst->u.get.ubuf, &pt->r16,
1557 				ELF_GR_OFFSET(16), ELF_NAT_OFFSET);
1558 		if (dst->ret || dst->count == 0)
1559 			return;
1560 	}
1561 
1562 	/* nat, pr, b0 - b7 */
1563 	if (dst->count > 0 && dst->pos < ELF_CR_IIP_OFFSET) {
1564 		index = (dst->pos - ELF_NAT_OFFSET) / sizeof(elf_greg_t);
1565 		min_copy = ELF_CR_IIP_OFFSET > (dst->pos + dst->count) ?
1566 			 (dst->pos + dst->count) : ELF_CR_IIP_OFFSET;
1567 		for (i = dst->pos; i < min_copy; i += sizeof(elf_greg_t),
1568 				index++)
1569 			if (access_elf_reg(dst->target, info, i,
1570 						&tmp[index], 0) < 0) {
1571 				dst->ret = -EIO;
1572 				return;
1573 			}
1574 		dst->ret = user_regset_copyout(&dst->pos, &dst->count,
1575 				&dst->u.get.kbuf, &dst->u.get.ubuf, tmp,
1576 				ELF_NAT_OFFSET, ELF_CR_IIP_OFFSET);
1577 		if (dst->ret || dst->count == 0)
1578 			return;
1579 	}
1580 
1581 	/* ip cfm psr ar.rsc ar.bsp ar.bspstore ar.rnat
1582 	 * ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec ar.csd ar.ssd
1583 	 */
1584 	if (dst->count > 0 && dst->pos < (ELF_AR_END_OFFSET)) {
1585 		index = (dst->pos - ELF_CR_IIP_OFFSET) / sizeof(elf_greg_t);
1586 		min_copy = ELF_AR_END_OFFSET > (dst->pos + dst->count) ?
1587 			 (dst->pos + dst->count) : ELF_AR_END_OFFSET;
1588 		for (i = dst->pos; i < min_copy; i += sizeof(elf_greg_t),
1589 				index++)
1590 			if (access_elf_reg(dst->target, info, i,
1591 						&tmp[index], 0) < 0) {
1592 				dst->ret = -EIO;
1593 				return;
1594 			}
1595 		dst->ret = user_regset_copyout(&dst->pos, &dst->count,
1596 				&dst->u.get.kbuf, &dst->u.get.ubuf, tmp,
1597 				ELF_CR_IIP_OFFSET, ELF_AR_END_OFFSET);
1598 	}
1599 }
1600 
1601 void do_gpregs_set(struct unw_frame_info *info, void *arg)
1602 {
1603 	struct pt_regs *pt;
1604 	struct regset_getset *dst = arg;
1605 	elf_greg_t tmp[16];
1606 	unsigned int i, index;
1607 
1608 	if (unw_unwind_to_user(info) < 0)
1609 		return;
1610 
1611 	/* Skip r0 */
1612 	if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(1)) {
1613 		dst->ret = user_regset_copyin_ignore(&dst->pos, &dst->count,
1614 						       &dst->u.set.kbuf,
1615 						       &dst->u.set.ubuf,
1616 						       0, ELF_GR_OFFSET(1));
1617 		if (dst->ret || dst->count == 0)
1618 			return;
1619 	}
1620 
1621 	/* gr1-gr15 */
1622 	if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(16)) {
1623 		i = dst->pos;
1624 		index = (dst->pos - ELF_GR_OFFSET(1)) / sizeof(elf_greg_t);
1625 		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1626 				&dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
1627 				ELF_GR_OFFSET(1), ELF_GR_OFFSET(16));
1628 		if (dst->ret)
1629 			return;
1630 		for ( ; i < dst->pos; i += sizeof(elf_greg_t), index++)
1631 			if (access_elf_reg(dst->target, info, i,
1632 						&tmp[index], 1) < 0) {
1633 				dst->ret = -EIO;
1634 				return;
1635 			}
1636 		if (dst->count == 0)
1637 			return;
1638 	}
1639 
1640 	/* gr16-gr31 */
1641 	if (dst->count > 0 && dst->pos < ELF_NAT_OFFSET) {
1642 		pt = task_pt_regs(dst->target);
1643 		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1644 				&dst->u.set.kbuf, &dst->u.set.ubuf, &pt->r16,
1645 				ELF_GR_OFFSET(16), ELF_NAT_OFFSET);
1646 		if (dst->ret || dst->count == 0)
1647 			return;
1648 	}
1649 
1650 	/* nat, pr, b0 - b7 */
1651 	if (dst->count > 0 && dst->pos < ELF_CR_IIP_OFFSET) {
1652 		i = dst->pos;
1653 		index = (dst->pos - ELF_NAT_OFFSET) / sizeof(elf_greg_t);
1654 		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1655 				&dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
1656 				ELF_NAT_OFFSET, ELF_CR_IIP_OFFSET);
1657 		if (dst->ret)
1658 			return;
1659 		for (; i < dst->pos; i += sizeof(elf_greg_t), index++)
1660 			if (access_elf_reg(dst->target, info, i,
1661 						&tmp[index], 1) < 0) {
1662 				dst->ret = -EIO;
1663 				return;
1664 			}
1665 		if (dst->count == 0)
1666 			return;
1667 	}
1668 
1669 	/* ip cfm psr ar.rsc ar.bsp ar.bspstore ar.rnat
1670 	 * ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec ar.csd ar.ssd
1671 	 */
1672 	if (dst->count > 0 && dst->pos < (ELF_AR_END_OFFSET)) {
1673 		i = dst->pos;
1674 		index = (dst->pos - ELF_CR_IIP_OFFSET) / sizeof(elf_greg_t);
1675 		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1676 				&dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
1677 				ELF_CR_IIP_OFFSET, ELF_AR_END_OFFSET);
1678 		if (dst->ret)
1679 			return;
1680 		for ( ; i < dst->pos; i += sizeof(elf_greg_t), index++)
1681 			if (access_elf_reg(dst->target, info, i,
1682 						&tmp[index], 1) < 0) {
1683 				dst->ret = -EIO;
1684 				return;
1685 			}
1686 	}
1687 }
1688 
1689 #define ELF_FP_OFFSET(i)	(i * sizeof(elf_fpreg_t))
1690 
1691 void do_fpregs_get(struct unw_frame_info *info, void *arg)
1692 {
1693 	struct regset_getset *dst = arg;
1694 	struct task_struct *task = dst->target;
1695 	elf_fpreg_t tmp[30];
1696 	int index, min_copy, i;
1697 
1698 	if (unw_unwind_to_user(info) < 0)
1699 		return;
1700 
1701 	/* Skip pos 0 and 1 */
1702 	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(2)) {
1703 		dst->ret = user_regset_copyout_zero(&dst->pos, &dst->count,
1704 						      &dst->u.get.kbuf,
1705 						      &dst->u.get.ubuf,
1706 						      0, ELF_FP_OFFSET(2));
1707 		if (dst->count == 0 || dst->ret)
1708 			return;
1709 	}
1710 
1711 	/* fr2-fr31 */
1712 	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(32)) {
1713 		index = (dst->pos - ELF_FP_OFFSET(2)) / sizeof(elf_fpreg_t);
1714 
1715 		min_copy = min(((unsigned int)ELF_FP_OFFSET(32)),
1716 				dst->pos + dst->count);
1717 		for (i = dst->pos; i < min_copy; i += sizeof(elf_fpreg_t),
1718 				index++)
1719 			if (unw_get_fr(info, i / sizeof(elf_fpreg_t),
1720 					 &tmp[index])) {
1721 				dst->ret = -EIO;
1722 				return;
1723 			}
1724 		dst->ret = user_regset_copyout(&dst->pos, &dst->count,
1725 				&dst->u.get.kbuf, &dst->u.get.ubuf, tmp,
1726 				ELF_FP_OFFSET(2), ELF_FP_OFFSET(32));
1727 		if (dst->count == 0 || dst->ret)
1728 			return;
1729 	}
1730 
1731 	/* fph */
1732 	if (dst->count > 0) {
1733 		ia64_flush_fph(dst->target);
1734 		if (task->thread.flags & IA64_THREAD_FPH_VALID)
1735 			dst->ret = user_regset_copyout(
1736 				&dst->pos, &dst->count,
1737 				&dst->u.get.kbuf, &dst->u.get.ubuf,
1738 				&dst->target->thread.fph,
1739 				ELF_FP_OFFSET(32), -1);
1740 		else
1741 			/* Zero fill instead.  */
1742 			dst->ret = user_regset_copyout_zero(
1743 				&dst->pos, &dst->count,
1744 				&dst->u.get.kbuf, &dst->u.get.ubuf,
1745 				ELF_FP_OFFSET(32), -1);
1746 	}
1747 }
1748 
1749 void do_fpregs_set(struct unw_frame_info *info, void *arg)
1750 {
1751 	struct regset_getset *dst = arg;
1752 	elf_fpreg_t fpreg, tmp[30];
1753 	int index, start, end;
1754 
1755 	if (unw_unwind_to_user(info) < 0)
1756 		return;
1757 
1758 	/* Skip pos 0 and 1 */
1759 	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(2)) {
1760 		dst->ret = user_regset_copyin_ignore(&dst->pos, &dst->count,
1761 						       &dst->u.set.kbuf,
1762 						       &dst->u.set.ubuf,
1763 						       0, ELF_FP_OFFSET(2));
1764 		if (dst->count == 0 || dst->ret)
1765 			return;
1766 	}
1767 
1768 	/* fr2-fr31 */
1769 	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(32)) {
1770 		start = dst->pos;
1771 		end = min(((unsigned int)ELF_FP_OFFSET(32)),
1772 			 dst->pos + dst->count);
1773 		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1774 				&dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
1775 				ELF_FP_OFFSET(2), ELF_FP_OFFSET(32));
1776 		if (dst->ret)
1777 			return;
1778 
1779 		if (start & 0xF) { /* only write high part */
1780 			if (unw_get_fr(info, start / sizeof(elf_fpreg_t),
1781 					 &fpreg)) {
1782 				dst->ret = -EIO;
1783 				return;
1784 			}
1785 			tmp[start / sizeof(elf_fpreg_t) - 2].u.bits[0]
1786 				= fpreg.u.bits[0];
1787 			start &= ~0xFUL;
1788 		}
1789 		if (end & 0xF) { /* only write low part */
1790 			if (unw_get_fr(info, end / sizeof(elf_fpreg_t),
1791 					&fpreg)) {
1792 				dst->ret = -EIO;
1793 				return;
1794 			}
1795 			tmp[end / sizeof(elf_fpreg_t) - 2].u.bits[1]
1796 				= fpreg.u.bits[1];
1797 			end = (end + 0xF) & ~0xFUL;
1798 		}
1799 
1800 		for ( ;	start < end ; start += sizeof(elf_fpreg_t)) {
1801 			index = start / sizeof(elf_fpreg_t);
1802 			if (unw_set_fr(info, index, tmp[index - 2])) {
1803 				dst->ret = -EIO;
1804 				return;
1805 			}
1806 		}
1807 		if (dst->ret || dst->count == 0)
1808 			return;
1809 	}
1810 
1811 	/* fph */
1812 	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(128)) {
1813 		ia64_sync_fph(dst->target);
1814 		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1815 						&dst->u.set.kbuf,
1816 						&dst->u.set.ubuf,
1817 						&dst->target->thread.fph,
1818 						ELF_FP_OFFSET(32), -1);
1819 	}
1820 }
1821 
1822 static int
1823 do_regset_call(void (*call)(struct unw_frame_info *, void *),
1824 	       struct task_struct *target,
1825 	       const struct user_regset *regset,
1826 	       unsigned int pos, unsigned int count,
1827 	       const void *kbuf, const void __user *ubuf)
1828 {
1829 	struct regset_getset info = { .target = target, .regset = regset,
1830 				 .pos = pos, .count = count,
1831 				 .u.set = { .kbuf = kbuf, .ubuf = ubuf },
1832 				 .ret = 0 };
1833 
1834 	if (target == current)
1835 		unw_init_running(call, &info);
1836 	else {
1837 		struct unw_frame_info ufi;
1838 		memset(&ufi, 0, sizeof(ufi));
1839 		unw_init_from_blocked_task(&ufi, target);
1840 		(*call)(&ufi, &info);
1841 	}
1842 
1843 	return info.ret;
1844 }
1845 
1846 static int
1847 gpregs_get(struct task_struct *target,
1848 	   const struct user_regset *regset,
1849 	   unsigned int pos, unsigned int count,
1850 	   void *kbuf, void __user *ubuf)
1851 {
1852 	return do_regset_call(do_gpregs_get, target, regset, pos, count,
1853 		kbuf, ubuf);
1854 }
1855 
1856 static int gpregs_set(struct task_struct *target,
1857 		const struct user_regset *regset,
1858 		unsigned int pos, unsigned int count,
1859 		const void *kbuf, const void __user *ubuf)
1860 {
1861 	return do_regset_call(do_gpregs_set, target, regset, pos, count,
1862 		kbuf, ubuf);
1863 }
1864 
1865 static void do_gpregs_writeback(struct unw_frame_info *info, void *arg)
1866 {
1867 	do_sync_rbs(info, ia64_sync_user_rbs);
1868 }
1869 
1870 /*
1871  * This is called to write back the register backing store.
1872  * ptrace does this before it stops, so that a tracer reading the user
1873  * memory after the thread stops will get the current register data.
1874  */
1875 static int
1876 gpregs_writeback(struct task_struct *target,
1877 		 const struct user_regset *regset,
1878 		 int now)
1879 {
1880 	if (test_and_set_tsk_thread_flag(target, TIF_RESTORE_RSE))
1881 		return 0;
1882 	set_notify_resume(target);
1883 	return do_regset_call(do_gpregs_writeback, target, regset, 0, 0,
1884 		NULL, NULL);
1885 }
1886 
1887 static int
1888 fpregs_active(struct task_struct *target, const struct user_regset *regset)
1889 {
1890 	return (target->thread.flags & IA64_THREAD_FPH_VALID) ? 128 : 32;
1891 }
1892 
1893 static int fpregs_get(struct task_struct *target,
1894 		const struct user_regset *regset,
1895 		unsigned int pos, unsigned int count,
1896 		void *kbuf, void __user *ubuf)
1897 {
1898 	return do_regset_call(do_fpregs_get, target, regset, pos, count,
1899 		kbuf, ubuf);
1900 }
1901 
1902 static int fpregs_set(struct task_struct *target,
1903 		const struct user_regset *regset,
1904 		unsigned int pos, unsigned int count,
1905 		const void *kbuf, const void __user *ubuf)
1906 {
1907 	return do_regset_call(do_fpregs_set, target, regset, pos, count,
1908 		kbuf, ubuf);
1909 }
1910 
1911 static int
1912 access_uarea(struct task_struct *child, unsigned long addr,
1913 	      unsigned long *data, int write_access)
1914 {
1915 	unsigned int pos = -1; /* an invalid value */
1916 	int ret;
1917 	unsigned long *ptr, regnum;
1918 
1919 	if ((addr & 0x7) != 0) {
1920 		dprintk("ptrace: unaligned register address 0x%lx\n", addr);
1921 		return -1;
1922 	}
1923 	if ((addr >= PT_NAT_BITS + 8 && addr < PT_F2) ||
1924 		(addr >= PT_R7 + 8 && addr < PT_B1) ||
1925 		(addr >= PT_AR_LC + 8 && addr < PT_CR_IPSR) ||
1926 		(addr >= PT_AR_SSD + 8 && addr < PT_DBR)) {
1927 		dprintk("ptrace: rejecting access to register "
1928 					"address 0x%lx\n", addr);
1929 		return -1;
1930 	}
1931 
1932 	switch (addr) {
1933 	case PT_F32 ... (PT_F127 + 15):
1934 		pos = addr - PT_F32 + ELF_FP_OFFSET(32);
1935 		break;
1936 	case PT_F2 ... (PT_F5 + 15):
1937 		pos = addr - PT_F2 + ELF_FP_OFFSET(2);
1938 		break;
1939 	case PT_F10 ... (PT_F31 + 15):
1940 		pos = addr - PT_F10 + ELF_FP_OFFSET(10);
1941 		break;
1942 	case PT_F6 ... (PT_F9 + 15):
1943 		pos = addr - PT_F6 + ELF_FP_OFFSET(6);
1944 		break;
1945 	}
1946 
1947 	if (pos != -1) {
1948 		if (write_access)
1949 			ret = fpregs_set(child, NULL, pos,
1950 				sizeof(unsigned long), data, NULL);
1951 		else
1952 			ret = fpregs_get(child, NULL, pos,
1953 				sizeof(unsigned long), data, NULL);
1954 		if (ret != 0)
1955 			return -1;
1956 		return 0;
1957 	}
1958 
1959 	switch (addr) {
1960 	case PT_NAT_BITS:
1961 		pos = ELF_NAT_OFFSET;
1962 		break;
1963 	case PT_R4 ... PT_R7:
1964 		pos = addr - PT_R4 + ELF_GR_OFFSET(4);
1965 		break;
1966 	case PT_B1 ... PT_B5:
1967 		pos = addr - PT_B1 + ELF_BR_OFFSET(1);
1968 		break;
1969 	case PT_AR_EC:
1970 		pos = ELF_AR_EC_OFFSET;
1971 		break;
1972 	case PT_AR_LC:
1973 		pos = ELF_AR_LC_OFFSET;
1974 		break;
1975 	case PT_CR_IPSR:
1976 		pos = ELF_CR_IPSR_OFFSET;
1977 		break;
1978 	case PT_CR_IIP:
1979 		pos = ELF_CR_IIP_OFFSET;
1980 		break;
1981 	case PT_CFM:
1982 		pos = ELF_CFM_OFFSET;
1983 		break;
1984 	case PT_AR_UNAT:
1985 		pos = ELF_AR_UNAT_OFFSET;
1986 		break;
1987 	case PT_AR_PFS:
1988 		pos = ELF_AR_PFS_OFFSET;
1989 		break;
1990 	case PT_AR_RSC:
1991 		pos = ELF_AR_RSC_OFFSET;
1992 		break;
1993 	case PT_AR_RNAT:
1994 		pos = ELF_AR_RNAT_OFFSET;
1995 		break;
1996 	case PT_AR_BSPSTORE:
1997 		pos = ELF_AR_BSPSTORE_OFFSET;
1998 		break;
1999 	case PT_PR:
2000 		pos = ELF_PR_OFFSET;
2001 		break;
2002 	case PT_B6:
2003 		pos = ELF_BR_OFFSET(6);
2004 		break;
2005 	case PT_AR_BSP:
2006 		pos = ELF_AR_BSP_OFFSET;
2007 		break;
2008 	case PT_R1 ... PT_R3:
2009 		pos = addr - PT_R1 + ELF_GR_OFFSET(1);
2010 		break;
2011 	case PT_R12 ... PT_R15:
2012 		pos = addr - PT_R12 + ELF_GR_OFFSET(12);
2013 		break;
2014 	case PT_R8 ... PT_R11:
2015 		pos = addr - PT_R8 + ELF_GR_OFFSET(8);
2016 		break;
2017 	case PT_R16 ... PT_R31:
2018 		pos = addr - PT_R16 + ELF_GR_OFFSET(16);
2019 		break;
2020 	case PT_AR_CCV:
2021 		pos = ELF_AR_CCV_OFFSET;
2022 		break;
2023 	case PT_AR_FPSR:
2024 		pos = ELF_AR_FPSR_OFFSET;
2025 		break;
2026 	case PT_B0:
2027 		pos = ELF_BR_OFFSET(0);
2028 		break;
2029 	case PT_B7:
2030 		pos = ELF_BR_OFFSET(7);
2031 		break;
2032 	case PT_AR_CSD:
2033 		pos = ELF_AR_CSD_OFFSET;
2034 		break;
2035 	case PT_AR_SSD:
2036 		pos = ELF_AR_SSD_OFFSET;
2037 		break;
2038 	}
2039 
2040 	if (pos != -1) {
2041 		if (write_access)
2042 			ret = gpregs_set(child, NULL, pos,
2043 				sizeof(unsigned long), data, NULL);
2044 		else
2045 			ret = gpregs_get(child, NULL, pos,
2046 				sizeof(unsigned long), data, NULL);
2047 		if (ret != 0)
2048 			return -1;
2049 		return 0;
2050 	}
2051 
2052 	/* access debug registers */
2053 	if (addr >= PT_IBR) {
2054 		regnum = (addr - PT_IBR) >> 3;
2055 		ptr = &child->thread.ibr[0];
2056 	} else {
2057 		regnum = (addr - PT_DBR) >> 3;
2058 		ptr = &child->thread.dbr[0];
2059 	}
2060 
2061 	if (regnum >= 8) {
2062 		dprintk("ptrace: rejecting access to register "
2063 				"address 0x%lx\n", addr);
2064 		return -1;
2065 	}
2066 #ifdef CONFIG_PERFMON
2067 	/*
2068 	 * Check if debug registers are used by perfmon. This
2069 	 * test must be done once we know that we can do the
2070 	 * operation, i.e. the arguments are all valid, but
2071 	 * before we start modifying the state.
2072 	 *
2073 	 * Perfmon needs to keep a count of how many processes
2074 	 * are trying to modify the debug registers for system
2075 	 * wide monitoring sessions.
2076 	 *
2077 	 * We also include read access here, because they may
2078 	 * cause the PMU-installed debug register state
2079 	 * (dbr[], ibr[]) to be reset. The two arrays are also
2080 	 * used by perfmon, but we do not use
2081 	 * IA64_THREAD_DBG_VALID. The registers are restored
2082 	 * by the PMU context switch code.
2083 	 */
2084 	if (pfm_use_debug_registers(child))
2085 		return -1;
2086 #endif
2087 
2088 	if (!(child->thread.flags & IA64_THREAD_DBG_VALID)) {
2089 		child->thread.flags |= IA64_THREAD_DBG_VALID;
2090 		memset(child->thread.dbr, 0,
2091 				sizeof(child->thread.dbr));
2092 		memset(child->thread.ibr, 0,
2093 				sizeof(child->thread.ibr));
2094 	}
2095 
2096 	ptr += regnum;
2097 
2098 	if ((regnum & 1) && write_access) {
2099 		/* don't let the user set kernel-level breakpoints: */
2100 		*ptr = *data & ~(7UL << 56);
2101 		return 0;
2102 	}
2103 	if (write_access)
2104 		*ptr = *data;
2105 	else
2106 		*data = *ptr;
2107 	return 0;
2108 }
2109 
2110 static const struct user_regset native_regsets[] = {
2111 	{
2112 		.core_note_type = NT_PRSTATUS,
2113 		.n = ELF_NGREG,
2114 		.size = sizeof(elf_greg_t), .align = sizeof(elf_greg_t),
2115 		.get = gpregs_get, .set = gpregs_set,
2116 		.writeback = gpregs_writeback
2117 	},
2118 	{
2119 		.core_note_type = NT_PRFPREG,
2120 		.n = ELF_NFPREG,
2121 		.size = sizeof(elf_fpreg_t), .align = sizeof(elf_fpreg_t),
2122 		.get = fpregs_get, .set = fpregs_set, .active = fpregs_active
2123 	},
2124 };
2125 
2126 static const struct user_regset_view user_ia64_view = {
2127 	.name = "ia64",
2128 	.e_machine = EM_IA_64,
2129 	.regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
2130 };
2131 
2132 const struct user_regset_view *task_user_regset_view(struct task_struct *tsk)
2133 {
2134 	return &user_ia64_view;
2135 }
2136 
2137 struct syscall_get_set_args {
2138 	unsigned int i;
2139 	unsigned int n;
2140 	unsigned long *args;
2141 	struct pt_regs *regs;
2142 	int rw;
2143 };
2144 
2145 static void syscall_get_set_args_cb(struct unw_frame_info *info, void *data)
2146 {
2147 	struct syscall_get_set_args *args = data;
2148 	struct pt_regs *pt = args->regs;
2149 	unsigned long *krbs, cfm, ndirty;
2150 	int i, count;
2151 
2152 	if (unw_unwind_to_user(info) < 0)
2153 		return;
2154 
2155 	cfm = pt->cr_ifs;
2156 	krbs = (unsigned long *)info->task + IA64_RBS_OFFSET/8;
2157 	ndirty = ia64_rse_num_regs(krbs, krbs + (pt->loadrs >> 19));
2158 
2159 	count = 0;
2160 	if (in_syscall(pt))
2161 		count = min_t(int, args->n, cfm & 0x7f);
2162 
2163 	for (i = 0; i < count; i++) {
2164 		if (args->rw)
2165 			*ia64_rse_skip_regs(krbs, ndirty + i + args->i) =
2166 				args->args[i];
2167 		else
2168 			args->args[i] = *ia64_rse_skip_regs(krbs,
2169 				ndirty + i + args->i);
2170 	}
2171 
2172 	if (!args->rw) {
2173 		while (i < args->n) {
2174 			args->args[i] = 0;
2175 			i++;
2176 		}
2177 	}
2178 }
2179 
2180 void ia64_syscall_get_set_arguments(struct task_struct *task,
2181 	struct pt_regs *regs, unsigned int i, unsigned int n,
2182 	unsigned long *args, int rw)
2183 {
2184 	struct syscall_get_set_args data = {
2185 		.i = i,
2186 		.n = n,
2187 		.args = args,
2188 		.regs = regs,
2189 		.rw = rw,
2190 	};
2191 
2192 	if (task == current)
2193 		unw_init_running(syscall_get_set_args_cb, &data);
2194 	else {
2195 		struct unw_frame_info ufi;
2196 		memset(&ufi, 0, sizeof(ufi));
2197 		unw_init_from_blocked_task(&ufi, task);
2198 		syscall_get_set_args_cb(&ufi, &data);
2199 	}
2200 }
2201