aboutsummaryrefslogblamecommitdiffstats
path: root/arch/ia64/kernel/ptrace.c
blob: b61afbbe076f6152935e79fca3eb7da61f251c71 (plain) (tree)
1
2
3
4
5
6
7
8
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917




                                                                  


                                                                    


                                           





                         


                           
                         

                         
                            











































































































































































































































                                                                               
                                


























































                                                                              
                                



























































































                                                                              
                                         


























































                                                                              
                                         















































































                                                                             


















































                                                                               
                                   








                                                          



                                                            

























                                                                            
                                                 





























                                                                         


















                                                                      
                                           







                                                                           




                                                                   
                                                            
 




                                            




                                                            
                         












                                                                      
                                                            









                                                                       








                                                                            
                                 





                                                 




                                                                           
                                                     





                                                                  
                                              
                               


                                                       


                              





                                                                      
                                    
                                                                     



                                         













                                                                    






































                                                                       
                                                     















                                                                               
                                 


































































































































                                                                               
                                                                          











                                                                          
                                 


















                                                                       
                                                        
































































































                                                                               
                                                          










                                                                 




























                                                                           







                                             
                                        

 

                                                                           
 
                          

                             
                                                
                                                                          


                                                                        
                                                  
                            
 


                                                         
 
                            
                                                            


                                                                        
                                                  
                            
 
                            
                                                             


                                                            
 
                                   
                                                 
                                                                            
 
                                   
                                                 











                                                                               
         


 

                                                          
               



                                                                


                                                          
 



                                              
                                               


                             

                                       
 
                                                                           

         
                 








                                                                

                 





                                                       
                                                    
         
 


                                                           



                                              
 





















































































































































































































































































































































































































































































































































































































































                                                                                
                                  



























                                                                           






































































































































































































                                                                            

























                                                                             
































































                                                                            
/*
 * Kernel support for the ptrace() and syscall tracing interfaces.
 *
 * Copyright (C) 1999-2005 Hewlett-Packard Co
 *	David Mosberger-Tang <davidm@hpl.hp.com>
 * Copyright (C) 2006 Intel Co
 *  2006-08-12	- IA64 Native Utrace implementation support added by
 *	Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
 *
 * Derived from the x86 and Alpha versions.
 */
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/security.h>
#include <linux/audit.h>
#include <linux/signal.h>
#include <linux/regset.h>
#include <linux/elf.h>
#include <linux/tracehook.h>

#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/ptrace_offsets.h>
#include <asm/rse.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/unwind.h>
#ifdef CONFIG_PERFMON
#include <asm/perfmon.h>
#endif

#include "entry.h"

/*
 * Bits in the PSR that we allow ptrace() to change:
 *	be, up, ac, mfl, mfh (the user mask; five bits total)
 *	db (debug breakpoint fault; one bit)
 *	id (instruction debug fault disable; one bit)
 *	dd (data debug fault disable; one bit)
 *	ri (restart instruction; two bits)
 *	is (instruction set; one bit)
 */
#define IPSR_MASK (IA64_PSR_UM | IA64_PSR_DB | IA64_PSR_IS	\
		   | IA64_PSR_ID | IA64_PSR_DD | IA64_PSR_RI)

#define MASK(nbits)	((1UL << (nbits)) - 1)	/* mask with NBITS bits set */
#define PFM_MASK	MASK(38)

#define PTRACE_DEBUG	0

#if PTRACE_DEBUG
# define dprintk(format...)	printk(format)
# define inline
#else
# define dprintk(format...)
#endif

/* Return TRUE if PT was created due to kernel-entry via a system-call.  */

static inline int
in_syscall (struct pt_regs *pt)
{
	return (long) pt->cr_ifs >= 0;
}

/*
 * Collect the NaT bits for r1-r31 from scratch_unat and return a NaT
 * bitset where bit i is set iff the NaT bit of register i is set.
 */
unsigned long
ia64_get_scratch_nat_bits (struct pt_regs *pt, unsigned long scratch_unat)
{
#	define GET_BITS(first, last, unat)				\
	({								\
		unsigned long bit = ia64_unat_pos(&pt->r##first);	\
		unsigned long nbits = (last - first + 1);		\
		unsigned long mask = MASK(nbits) << first;		\
		unsigned long dist;					\
		if (bit < first)					\
			dist = 64 + bit - first;			\
		else							\
			dist = bit - first;				\
		ia64_rotr(unat, dist) & mask;				\
	})
	unsigned long val;

	/*
	 * Registers that are stored consecutively in struct pt_regs
	 * can be handled in parallel.  If the register order in
	 * struct_pt_regs changes, this code MUST be updated.
	 */
	val  = GET_BITS( 1,  1, scratch_unat);
	val |= GET_BITS( 2,  3, scratch_unat);
	val |= GET_BITS(12, 13, scratch_unat);
	val |= GET_BITS(14, 14, scratch_unat);
	val |= GET_BITS(15, 15, scratch_unat);
	val |= GET_BITS( 8, 11, scratch_unat);
	val |= GET_BITS(16, 31, scratch_unat);
	return val;

#	undef GET_BITS
}

/*
 * Set the NaT bits for the scratch registers according to NAT and
 * return the resulting unat (assuming the scratch registers are
 * stored in PT).
 */
unsigned long
ia64_put_scratch_nat_bits (struct pt_regs *pt, unsigned long nat)
{
#	define PUT_BITS(first, last, nat)				\
	({								\
		unsigned long bit = ia64_unat_pos(&pt->r##first);	\
		unsigned long nbits = (last - first + 1);		\
		unsigned long mask = MASK(nbits) << first;		\
		long dist;						\
		if (bit < first)					\
			dist = 64 + bit - first;			\
		else							\
			dist = bit - first;				\
		ia64_rotl(nat & mask, dist);				\
	})
	unsigned long scratch_unat;

	/*
	 * Registers that are stored consecutively in struct pt_regs
	 * can be handled in parallel.  If the register order in
	 * struct_pt_regs changes, this code MUST be updated.
	 */
	scratch_unat  = PUT_BITS( 1,  1, nat);
	scratch_unat |= PUT_BITS( 2,  3, nat);
	scratch_unat |= PUT_BITS(12, 13, nat);
	scratch_unat |= PUT_BITS(14, 14, nat);
	scratch_unat |= PUT_BITS(15, 15, nat);
	scratch_unat |= PUT_BITS( 8, 11, nat);
	scratch_unat |= PUT_BITS(16, 31, nat);

	return scratch_unat;

#	undef PUT_BITS
}

#define IA64_MLX_TEMPLATE	0x2
#define IA64_MOVL_OPCODE	6

void
ia64_increment_ip (struct pt_regs *regs)
{
	unsigned long w0, ri = ia64_psr(regs)->ri + 1;

	if (ri > 2) {
		ri = 0;
		regs->cr_iip += 16;
	} else if (ri == 2) {
		get_user(w0, (char __user *) regs->cr_iip + 0);
		if (((w0 >> 1) & 0xf) == IA64_MLX_TEMPLATE) {
			/*
			 * rfi'ing to slot 2 of an MLX bundle causes
			 * an illegal operation fault.  We don't want
			 * that to happen...
			 */
			ri = 0;
			regs->cr_iip += 16;
		}
	}
	ia64_psr(regs)->ri = ri;
}

void
ia64_decrement_ip (struct pt_regs *regs)
{
	unsigned long w0, ri = ia64_psr(regs)->ri - 1;

	if (ia64_psr(regs)->ri == 0) {
		regs->cr_iip -= 16;
		ri = 2;
		get_user(w0, (char __user *) regs->cr_iip + 0);
		if (((w0 >> 1) & 0xf) == IA64_MLX_TEMPLATE) {
			/*
			 * rfi'ing to slot 2 of an MLX bundle causes
			 * an illegal operation fault.  We don't want
			 * that to happen...
			 */
			ri = 1;
		}
	}
	ia64_psr(regs)->ri = ri;
}

/*
 * This routine is used to read an rnat bits that are stored on the
 * kernel backing store.  Since, in general, the alignment of the user
 * and kernel are different, this is not completely trivial.  In
 * essence, we need to construct the user RNAT based on up to two
 * kernel RNAT values and/or the RNAT value saved in the child's
 * pt_regs.
 *
 * user rbs
 *
 * +--------+ <-- lowest address
 * | slot62 |
 * +--------+
 * |  rnat  | 0x....1f8
 * +--------+
 * | slot00 | \
 * +--------+ |
 * | slot01 | > child_regs->ar_rnat
 * +--------+ |
 * | slot02 | /				kernel rbs
 * +--------+				+--------+
 *	    <- child_regs->ar_bspstore	| slot61 | <-- krbs
 * +- - - - +				+--------+
 *					| slot62 |
 * +- - - - +				+--------+
 *					|  rnat	 |
 * +- - - - +				+--------+
 *   vrnat				| slot00 |
 * +- - - - +				+--------+
 *					=	 =
 *					+--------+
 *					| slot00 | \
 *					+--------+ |
 *					| slot01 | > child_stack->ar_rnat
 *					+--------+ |
 *					| slot02 | /
 *					+--------+
 *						  <--- child_stack->ar_bspstore
 *
 * The way to think of this code is as follows: bit 0 in the user rnat
 * corresponds to some bit N (0 <= N <= 62) in one of the kernel rnat
 * value.  The kernel rnat value holding this bit is stored in
 * variable rnat0.  rnat1 is loaded with the kernel rnat value that
 * form the upper bits of the user rnat value.
 *
 * Boundary cases:
 *
 * o when reading the rnat "below" the first rnat slot on the kernel
 *   backing store, rnat0/rnat1 are set to 0 and the low order bits are
 *   merged in from pt->ar_rnat.
 *
 * o when reading the rnat "above" the last rnat slot on the kernel
 *   backing store, rnat0/rnat1 gets its value from sw->ar_rnat.
 */
static unsigned long
get_rnat (struct task_struct *task, struct switch_stack *sw,
	  unsigned long *krbs, unsigned long *urnat_addr,
	  unsigned long *urbs_end)
{
	unsigned long rnat0 = 0, rnat1 = 0, urnat = 0, *slot0_kaddr;
	unsigned long umask = 0, mask, m;
	unsigned long *kbsp, *ubspstore, *rnat0_kaddr, *rnat1_kaddr, shift;
	long num_regs, nbits;
	struct pt_regs *pt;

	pt = task_pt_regs(task);
	kbsp = (unsigned long *) sw->ar_bspstore;
	ubspstore = (unsigned long *) pt->ar_bspstore;

	if (urbs_end < urnat_addr)
		nbits = ia64_rse_num_regs(urnat_addr - 63, urbs_end);
	else
		nbits = 63;
	mask = MASK(nbits);
	/*
	 * First, figure out which bit number slot 0 in user-land maps
	 * to in the kernel rnat.  Do this by figuring out how many
	 * register slots we're beyond the user's backingstore and
	 * then computing the equivalent address in kernel space.
	 */
	num_regs = ia64_rse_num_regs(ubspstore, urnat_addr + 1);
	slot0_kaddr = ia64_rse_skip_regs(krbs, num_regs);
	shift = ia64_rse_slot_num(slot0_kaddr);
	rnat1_kaddr = ia64_rse_rnat_addr(slot0_kaddr);
	rnat0_kaddr = rnat1_kaddr - 64;

	if (ubspstore + 63 > urnat_addr) {
		/* some bits need to be merged in from pt->ar_rnat */
		umask = MASK(ia64_rse_slot_num(ubspstore)) & mask;
		urnat = (pt->ar_rnat & umask);
		mask &= ~umask;
		if (!mask)
			return urnat;
	}

	m = mask << shift;
	if (rnat0_kaddr >= kbsp)
		rnat0 = sw->ar_rnat;
	else if (rnat0_kaddr > krbs)
		rnat0 = *rnat0_kaddr;
	urnat |= (rnat0 & m) >> shift;

	m = mask >> (63 - shift);
	if (rnat1_kaddr >= kbsp)
		rnat1 = sw->ar_rnat;
	else if (rnat1_kaddr > krbs)
		rnat1 = *rnat1_kaddr;
	urnat |= (rnat1 & m) << (63 - shift);
	return urnat;
}

/*
 * The reverse of get_rnat.
 */
static void
put_rnat (struct task_struct *task, struct switch_stack *sw,
	  unsigned long *krbs, unsigned long *urnat_addr, unsigned long urnat,
	  unsigned long *urbs_end)
{
	unsigned long rnat0 = 0, rnat1 = 0, *slot0_kaddr, umask = 0, mask, m;
	unsigned long *kbsp, *ubspstore, *rnat0_kaddr, *rnat1_kaddr, shift;
	long num_regs, nbits;
	struct pt_regs *pt;
	unsigned long cfm, *urbs_kargs;

	pt = task_pt_regs(task);
	kbsp = (unsigned long *) sw->ar_bspstore;
	ubspstore = (unsigned long *) pt->ar_bspstore;

	urbs_kargs = urbs_end;
	if (in_syscall(pt)) {
		/*
		 * If entered via syscall, don't allow user to set rnat bits
		 * for syscall args.
		 */
		cfm = pt->cr_ifs;
		urbs_kargs = ia64_rse_skip_regs(urbs_end, -(cfm & 0x7f));
	}

	if (urbs_kargs >= urnat_addr)
		nbits = 63;
	else {
		if ((urnat_addr - 63) >= urbs_kargs)
			return;
		nbits = ia64_rse_num_regs(urnat_addr - 63, urbs_kargs);
	}
	mask = MASK(nbits);

	/*
	 * First, figure out which bit number slot 0 in user-land maps
	 * to in the kernel rnat.  Do this by figuring out how many
	 * register slots we're beyond the user's backingstore and
	 * then computing the equivalent address in kernel space.
	 */
	num_regs = ia64_rse_num_regs(ubspstore, urnat_addr + 1);
	slot0_kaddr = ia64_rse_skip_regs(krbs, num_regs);
	shift = ia64_rse_slot_num(slot0_kaddr);
	rnat1_kaddr = ia64_rse_rnat_addr(slot0_kaddr);
	rnat0_kaddr = rnat1_kaddr - 64;

	if (ubspstore + 63 > urnat_addr) {
		/* some bits need to be place in pt->ar_rnat: */
		umask = MASK(ia64_rse_slot_num(ubspstore)) & mask;
		pt->ar_rnat = (pt->ar_rnat & ~umask) | (urnat & umask);
		mask &= ~umask;
		if (!mask)
			return;
	}
	/*
	 * Note: Section 11.1 of the EAS guarantees that bit 63 of an
	 * rnat slot is ignored. so we don't have to clear it here.
	 */
	rnat0 = (urnat << shift);
	m = mask << shift;
	if (rnat0_kaddr >= kbsp)
		sw->ar_rnat = (sw->ar_rnat & ~m) | (rnat0 & m);
	else if (rnat0_kaddr > krbs)
		*rnat0_kaddr = ((*rnat0_kaddr & ~m) | (rnat0 & m));

	rnat1 = (urnat >> (63 - shift));
	m = mask >> (63 - shift);
	if (rnat1_kaddr >= kbsp)
		sw->ar_rnat = (sw->ar_rnat & ~m) | (rnat1 & m);
	else if (rnat1_kaddr > krbs)
		*rnat1_kaddr = ((*rnat1_kaddr & ~m) | (rnat1 & m));
}

static inline int
on_kernel_rbs (unsigned long addr, unsigned long bspstore,
	       unsigned long urbs_end)
{
	unsigned long *rnat_addr = ia64_rse_rnat_addr((unsigned long *)
						      urbs_end);
	return (addr >= bspstore && addr <= (unsigned long) rnat_addr);
}

/*
 * Read a word from the user-level backing store of task CHILD.  ADDR
 * is the user-level address to read the word from, VAL a pointer to
 * the return value, and USER_BSP gives the end of the user-level
 * backing store (i.e., it's the address that would be in ar.bsp after
 * the user executed a "cover" instruction).
 *
 * This routine takes care of accessing the kernel register backing
 * store for those registers that got spilled there.  It also takes
 * care of calculating the appropriate RNaT collection words.
 */
long
ia64_peek (struct task_struct *child, struct switch_stack *child_stack,
	   unsigned long user_rbs_end, unsigned long addr, long *val)
{
	unsigned long *bspstore, *krbs, regnum, *laddr, *urbs_end, *rnat_addr;
	struct pt_regs *child_regs;
	size_t copied;
	long ret;

	urbs_end = (long *) user_rbs_end;
	laddr = (unsigned long *) addr;
	child_regs = task_pt_regs(child);
	bspstore = (unsigned long *) child_regs->ar_bspstore;
	krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
	if (on_kernel_rbs(addr, (unsigned long) bspstore,
			  (unsigned long) urbs_end))
	{
		/*
		 * Attempt to read the RBS in an area that's actually
		 * on the kernel RBS => read the corresponding bits in
		 * the kernel RBS.
		 */
		rnat_addr = ia64_rse_rnat_addr(laddr);
		ret = get_rnat(child, child_stack, krbs, rnat_addr, urbs_end);

		if (laddr == rnat_addr) {
			/* return NaT collection word itself */
			*val = ret;
			return 0;
		}

		if (((1UL << ia64_rse_slot_num(laddr)) & ret) != 0) {
			/*
			 * It is implementation dependent whether the
			 * data portion of a NaT value gets saved on a
			 * st8.spill or RSE spill (e.g., see EAS 2.6,
			 * 4.4.4.6 Register Spill and Fill).  To get
			 * consistent behavior across all possible
			 * IA-64 implementations, we return zero in
			 * this case.
			 */
			*val = 0;
			return 0;
		}

		if (laddr < urbs_end) {
			/*
			 * The desired word is on the kernel RBS and
			 * is not a NaT.
			 */
			regnum = ia64_rse_num_regs(bspstore, laddr);
			*val = *ia64_rse_skip_regs(krbs, regnum);
			return 0;
		}
	}
	copied = access_process_vm(child, addr, &ret, sizeof(ret), 0);
	if (copied != sizeof(ret))
		return -EIO;
	*val = ret;
	return 0;
}

long
ia64_poke (struct task_struct *child, struct switch_stack *child_stack,
	   unsigned long user_rbs_end, unsigned long addr, long val)
{
	unsigned long *bspstore, *krbs, regnum, *laddr;
	unsigned long *urbs_end = (long *) user_rbs_end;
	struct pt_regs *child_regs;

	laddr = (unsigned long *) addr;
	child_regs = task_pt_regs(child);
	bspstore = (unsigned long *) child_regs->ar_bspstore;
	krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
	if (on_kernel_rbs(addr, (unsigned long) bspstore,
			  (unsigned long) urbs_end))
	{
		/*
		 * Attempt to write the RBS in an area that's actually
		 * on the kernel RBS => write the corresponding bits
		 * in the kernel RBS.
		 */
		if (ia64_rse_is_rnat_slot(laddr))
			put_rnat(child, child_stack, krbs, laddr, val,
				 urbs_end);
		else {
			if (laddr < urbs_end) {
				regnum = ia64_rse_num_regs(bspstore, laddr);
				*ia64_rse_skip_regs(krbs, regnum) = val;
			}
		}
	} else if (access_process_vm(child, addr, &val, sizeof(val), 1)
		   != sizeof(val))
		return -EIO;
	return 0;
}

/*
 * Calculate the address of the end of the user-level register backing
 * store.  This is the address that would have been stored in ar.bsp
 * if the user had executed a "cover" instruction right before
 * entering the kernel.  If CFMP is not NULL, it is used to return the
 * "current frame mask" that was active at the time the kernel was
 * entered.
 */
unsigned long
ia64_get_user_rbs_end (struct task_struct *child, struct pt_regs *pt,
		       unsigned long *cfmp)
{
	unsigned long *krbs, *bspstore, cfm = pt->cr_ifs;
	long ndirty;

	krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
	bspstore = (unsigned long *) pt->ar_bspstore;
	ndirty = ia64_rse_num_regs(krbs, krbs + (pt->loadrs >> 19));

	if (in_syscall(pt))
		ndirty += (cfm & 0x7f);
	else
		cfm &= ~(1UL << 63);	/* clear valid bit */

	if (cfmp)
		*cfmp = cfm;
	return (unsigned long) ia64_rse_skip_regs(bspstore, ndirty);
}

/*
 * Synchronize (i.e, write) the RSE backing store living in kernel
 * space to the VM of the CHILD task.  SW and PT are the pointers to
 * the switch_stack and pt_regs structures, respectively.
 * USER_RBS_END is the user-level address at which the backing store
 * ends.
 */
long
ia64_sync_user_rbs (struct task_struct *child, struct switch_stack *sw,
		    unsigned long user_rbs_start, unsigned long user_rbs_end)
{
	unsigned long addr, val;
	long ret;

	/* now copy word for word from kernel rbs to user rbs: */
	for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) {
		ret = ia64_peek(child, sw, user_rbs_end, addr, &val);
		if (ret < 0)
			return ret;
		if (access_process_vm(child, addr, &val, sizeof(val), 1)
		    != sizeof(val))
			return -EIO;
	}
	return 0;
}

static long
ia64_sync_kernel_rbs (struct task_struct *child, struct switch_stack *sw,
		unsigned long user_rbs_start, unsigned long user_rbs_end)
{
	unsigned long addr, val;
	long ret;

	/* now copy word for word from user rbs to kernel rbs: */
	for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) {
		if (access_process_vm(child, addr, &val, sizeof(val), 0)
				!= sizeof(val))
			return -EIO;

		ret = ia64_poke(child, sw, user_rbs_end, addr, val);
		if (ret < 0)
			return ret;
	}
	return 0;
}

typedef long (*syncfunc_t)(struct task_struct *, struct switch_stack *,
			    unsigned long, unsigned long);

static void do_sync_rbs(struct unw_frame_info *info, void *arg)
{
	struct pt_regs *pt;
	unsigned long urbs_end;
	syncfunc_t fn = arg;

	if (unw_unwind_to_user(info) < 0)
		return;
	pt = task_pt_regs(info->task);
	urbs_end = ia64_get_user_rbs_end(info->task, pt, NULL);

	fn(info->task, info->sw, pt->ar_bspstore, urbs_end);
}

/*
 * when a thread is stopped (ptraced), debugger might change thread's user
 * stack (change memory directly), and we must avoid the RSE stored in kernel
 * to override user stack (user space's RSE is newer than kernel's in the
 * case). To workaround the issue, we copy kernel RSE to user RSE before the
 * task is stopped, so user RSE has updated data.  we then copy user RSE to
 * kernel after the task is resummed from traced stop and kernel will use the
 * newer RSE to return to user. TIF_RESTORE_RSE is the flag to indicate we need
 * synchronize user RSE to kernel.
 */
void ia64_ptrace_stop(void)
{
	if (test_and_set_tsk_thread_flag(current, TIF_RESTORE_RSE))
		return;
	set_notify_resume(current);
	unw_init_running(do_sync_rbs, ia64_sync_user_rbs);
}

/*
 * This is called to read back the register backing store.
 */
void ia64_sync_krbs(void)
{
	clear_tsk_thread_flag(current, TIF_RESTORE_RSE);

	unw_init_running(do_sync_rbs, ia64_sync_kernel_rbs);
}

/*
 * After PTRACE_ATTACH, a thread's register backing store area in user
 * space is assumed to contain correct data whenever the thread is
 * stopped.  arch_ptrace_stop takes care of this on tracing stops.
 * But if the child was already stopped for job control when we attach
 * to it, then it might not ever get into ptrace_stop by the time we
 * want to examine the user memory containing the RBS.
 */
void
ptrace_attach_sync_user_rbs (struct task_struct *child)
{
	int stopped = 0;
	struct unw_frame_info info;

	/*
	 * If the child is in TASK_STOPPED, we need to change that to
	 * TASK_TRACED momentarily while we operate on it.  This ensures
	 * that the child won't be woken up and return to user mode while
	 * we are doing the sync.  (It can only be woken up for SIGKILL.)
	 */

	read_lock(&tasklist_lock);
	if (child->signal) {
		spin_lock_irq(&child->sighand->siglock);
		if (child->state == TASK_STOPPED &&
		    !test_and_set_tsk_thread_flag(child, TIF_RESTORE_RSE)) {
			set_notify_resume(child);

			child->state = TASK_TRACED;
			stopped = 1;
		}
		spin_unlock_irq(&child->sighand->siglock);
	}
	read_unlock(&tasklist_lock);

	if (!stopped)
		return;

	unw_init_from_blocked_task(&info, child);
	do_sync_rbs(&info, ia64_sync_user_rbs);

	/*
	 * Now move the child back into TASK_STOPPED if it should be in a
	 * job control stop, so that SIGCONT can be used to wake it up.
	 */
	read_lock(&tasklist_lock);
	if (child->signal) {
		spin_lock_irq(&child->sighand->siglock);
		if (child->state == TASK_TRACED &&
		    (child->signal->flags & SIGNAL_STOP_STOPPED)) {
			child->state = TASK_STOPPED;
		}
		spin_unlock_irq(&child->sighand->siglock);
	}
	read_unlock(&tasklist_lock);
}

static inline int
thread_matches (struct task_struct *thread, unsigned long addr)
{
	unsigned long thread_rbs_end;
	struct pt_regs *thread_regs;

	if (ptrace_check_attach(thread, 0) < 0)
		/*
		 * If the thread is not in an attachable state, we'll
		 * ignore it.  The net effect is that if ADDR happens
		 * to overlap with the portion of the thread's
		 * register backing store that is currently residing
		 * on the thread's kernel stack, then ptrace() may end
		 * up accessing a stale value.  But if the thread
		 * isn't stopped, that's a problem anyhow, so we're
		 * doing as well as we can...
		 */
		return 0;

	thread_regs = task_pt_regs(thread);
	thread_rbs_end = ia64_get_user_rbs_end(thread, thread_regs, NULL);
	if (!on_kernel_rbs(addr, thread_regs->ar_bspstore, thread_rbs_end))
		return 0;

	return 1;	/* looks like we've got a winner */
}

/*
 * Write f32-f127 back to task->thread.fph if it has been modified.
 */
inline void
ia64_flush_fph (struct task_struct *task)
{
	struct ia64_psr *psr = ia64_psr(task_pt_regs(task));

	/*
	 * Prevent migrating this task while
	 * we're fiddling with the FPU state
	 */
	preempt_disable();
	if (ia64_is_local_fpu_owner(task) && psr->mfh) {
		psr->mfh = 0;
		task->thread.flags |= IA64_THREAD_FPH_VALID;
		ia64_save_fpu(&task->thread.fph[0]);
	}
	preempt_enable();
}

/*
 * Sync the fph state of the task so that it can be manipulated
 * through thread.fph.  If necessary, f32-f127 are written back to
 * thread.fph or, if the fph state hasn't been used before, thread.fph
 * is cleared to zeroes.  Also, access to f32-f127 is disabled to
 * ensure that the task picks up the state from thread.fph when it
 * executes again.
 */
void
ia64_sync_fph (struct task_struct *task)
{
	struct ia64_psr *psr = ia64_psr(task_pt_regs(task));

	ia64_flush_fph(task);
	if (!(task->thread.flags & IA64_THREAD_FPH_VALID)) {
		task->thread.flags |= IA64_THREAD_FPH_VALID;
		memset(&task->thread.fph, 0, sizeof(task->thread.fph));
	}
	ia64_drop_fpu(task);
	psr->dfh = 1;
}

/*
 * Change the machine-state of CHILD such that it will return via the normal
 * kernel exit-path, rather than the syscall-exit path.
 */
static void
convert_to_non_syscall (struct task_struct *child, struct pt_regs  *pt,
			unsigned long cfm)
{
	struct unw_frame_info info, prev_info;
	unsigned long ip, sp, pr;

	unw_init_from_blocked_task(&info, child);
	while (1) {
		prev_info = info;
		if (unw_unwind(&info) < 0)
			return;

		unw_get_sp(&info, &sp);
		if ((long)((unsigned long)child + IA64_STK_OFFSET - sp)
		    < IA64_PT_REGS_SIZE) {
			dprintk("ptrace.%s: ran off the top of the kernel "
				"stack\n", __func__);
			return;
		}
		if (unw_get_pr (&prev_info, &pr) < 0) {
			unw_get_rp(&prev_info, &ip);
			dprintk("ptrace.%s: failed to read "
				"predicate register (ip=0x%lx)\n",
				__func__, ip);
			return;
		}
		if (unw_is_intr_frame(&info)
		    && (pr & (1UL << PRED_USER_STACK)))
			break;
	}

	/*
	 * Note: at the time of this call, the target task is blocked
	 * in notify_resume_user() and by clearling PRED_LEAVE_SYSCALL
	 * (aka, "pLvSys") we redirect execution from
	 * .work_pending_syscall_end to .work_processed_kernel.
	 */
	unw_get_pr(&prev_info, &pr);
	pr &= ~((1UL << PRED_SYSCALL) | (1UL << PRED_LEAVE_SYSCALL));
	pr |=  (1UL << PRED_NON_SYSCALL);
	unw_set_pr(&prev_info, pr);

	pt->cr_ifs = (1UL << 63) | cfm;
	/*
	 * Clear the memory that is NOT written on syscall-entry to
	 * ensure we do not leak kernel-state to user when execution
	 * resumes.
	 */
	pt->r2 = 0;
	pt->r3 = 0;
	pt->r14 = 0;
	memset(&pt->r16, 0, 16*8);	/* clear r16-r31 */
	memset(&pt->f6, 0, 6*16);	/* clear f6-f11 */
	pt->b7 = 0;
	pt->ar_ccv = 0;
	pt->ar_csd = 0;
	pt->ar_ssd = 0;
}

static int
access_nat_bits (struct task_struct *child, struct pt_regs *pt,
		 struct unw_frame_info *info,
		 unsigned long *data, int write_access)
{
	unsigned long regnum, nat_bits, scratch_unat, dummy = 0;
	char nat = 0;

	if (write_access) {
		nat_bits = *data;
		scratch_unat = ia64_put_scratch_nat_bits(pt, nat_bits);
		if (unw_set_ar(info, UNW_AR_UNAT, scratch_unat) < 0) {
			dprintk("ptrace: failed to set ar.unat\n");
			return -1;
		}
		for (regnum = 4; regnum <= 7; ++regnum) {
			unw_get_gr(info, regnum, &dummy, &nat);
			unw_set_gr(info, regnum, dummy,
				   (nat_bits >> regnum) & 1);
		}
	} else {
		if (unw_get_ar(info, UNW_AR_UNAT, &scratch_unat) < 0) {
			dprintk("ptrace: failed to read ar.unat\n");
			return -1;
		}
		nat_bits = ia64_get_scratch_nat_bits(pt, scratch_unat);
		for (regnum = 4; regnum <= 7; ++regnum) {
			unw_get_gr(info, regnum, &dummy, &nat);
			nat_bits |= (nat != 0) << regnum;
		}
		*data = nat_bits;
	}
	return 0;
}

static int
access_uarea (struct task_struct *child, unsigned long addr,
	      unsigned long *data, int write_access);

static long
ptrace_getregs (struct task_struct *child, struct pt_all_user_regs __user *ppr)
{
	unsigned long psr, ec, lc, rnat, bsp, cfm, nat_bits, val;
	struct unw_frame_info info;
	struct ia64_fpreg fpval;
	struct switch_stack *sw;
	struct pt_regs *pt;
	long ret, retval = 0;
	char nat = 0;
	int i;

	if (!access_ok(VERIFY_WRITE, ppr, sizeof(struct pt_all_user_regs)))
		return -EIO;

	pt = task_pt_regs(child);
	sw = (struct switch_stack *) (child->thread.ksp + 16);
	unw_init_from_blocked_task(&info, child);
	if (unw_unwind_to_user(&info) < 0) {
		return -EIO;
	}

	if (((unsigned long) ppr & 0x7) != 0) {
		dprintk("ptrace:unaligned register address %p\n", ppr);
		return -EIO;
	}

	if (access_uarea(child, PT_CR_IPSR, &psr, 0) < 0
	    || access_uarea(child, PT_AR_EC, &ec, 0) < 0
	    || access_uarea(child, PT_AR_LC, &lc, 0) < 0
	    || access_uarea(child, PT_AR_RNAT, &rnat, 0) < 0
	    || access_uarea(child, PT_AR_BSP, &bsp, 0) < 0
	    || access_uarea(child, PT_CFM, &cfm, 0)
	    || access_uarea(child, PT_NAT_BITS, &nat_bits, 0))
		return -EIO;

	/* control regs */

	retval |= __put_user(pt->cr_iip, &ppr->cr_iip);
	retval |= __put_user(psr, &ppr->cr_ipsr);

	/* app regs */

	retval |= __put_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
	retval |= __put_user(pt->ar_rsc, &ppr->ar[PT_AUR_RSC]);
	retval |= __put_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
	retval |= __put_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
	retval |= __put_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
	retval |= __put_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);

	retval |= __put_user(ec, &ppr->ar[PT_AUR_EC]);
	retval |= __put_user(lc, &ppr->ar[PT_AUR_LC]);
	retval |= __put_user(rnat, &ppr->ar[PT_AUR_RNAT]);
	retval |= __put_user(bsp, &ppr->ar[PT_AUR_BSP]);
	retval |= __put_user(cfm, &ppr->cfm);

	/* gr1-gr3 */

	retval |= __copy_to_user(&ppr->gr[1], &pt->r1, sizeof(long));
	retval |= __copy_to_user(&ppr->gr[2], &pt->r2, sizeof(long) *2);

	/* gr4-gr7 */

	for (i = 4; i < 8; i++) {
		if (unw_access_gr(&info, i, &val, &nat, 0) < 0)
			return -EIO;
		retval |= __put_user(val, &ppr->gr[i]);
	}

	/* gr8-gr11 */

	retval |= __copy_to_user(&ppr->gr[8], &pt->r8, sizeof(long) * 4);

	/* gr12-gr15 */

	retval |= __copy_to_user(&ppr->gr[12], &pt->r12, sizeof(long) * 2);
	retval |= __copy_to_user(&ppr->gr[14], &pt->r14, sizeof(long));
	retval |= __copy_to_user(&ppr->gr[15], &pt->r15, sizeof(long));

	/* gr16-gr31 */

	retval |= __copy_to_user(&ppr->gr[16], &pt->r16, sizeof(long) * 16);

	/* b0 */

	retval |= __put_user(pt->b0, &ppr->br[0]);

	/* b1-b5 */

	for (i = 1; i < 6; i++) {
		if (unw_access_br(&info, i, &val, 0) < 0)
			return -EIO;
		__put_user(val, &ppr->br[i]);
	}

	/* b6-b7 */

	retval |= __put_user(pt->b6, &ppr->br[6]);
	retval |= __put_user(pt->b7, &ppr->br[7]);

	/* fr2-fr5 */

	for (i = 2; i < 6; i++) {
		if (unw_get_fr(&info, i, &fpval) < 0)
			return -EIO;
		retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
	}

	/* fr6-fr11 */

	retval |= __copy_to_user(&ppr->fr[6], &pt->f6,
				 sizeof(struct ia64_fpreg) * 6);

	/* fp scratch regs(12-15) */

	retval |= __copy_to_user(&ppr->fr[12], &sw->f12,
				 sizeof(struct ia64_fpreg) * 4);

	/* fr16-fr31 */

	for (i = 16; i < 32; i++) {
		if (unw_get_fr(&info, i, &fpval) < 0)
			return -EIO;
		retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
	}

	/* fph */

	ia64_flush_fph(child);
	retval |= __copy_to_user(&ppr->fr[32], &child->thread.fph,
				 sizeof(ppr->fr[32]) * 96);

	/*  preds */

	retval |= __put_user(pt->pr, &ppr->pr);

	/* nat bits */

	retval |= __put_user(nat_bits, &ppr->nat);

	ret = retval ? -EIO : 0;
	return ret;
}

static long
ptrace_setregs (struct task_struct *child, struct pt_all_user_regs __user *ppr)
{
	unsigned long psr, rsc, ec, lc, rnat, bsp, cfm, nat_bits, val = 0;
	struct unw_frame_info info;
	struct switch_stack *sw;
	struct ia64_fpreg fpval;
	struct pt_regs *pt;
	long ret, retval = 0;
	int i;

	memset(&fpval, 0, sizeof(fpval));

	if (!access_ok(VERIFY_READ, ppr, sizeof(struct pt_all_user_regs)))
		return -EIO;

	pt = task_pt_regs(child);
	sw = (struct switch_stack *) (child->thread.ksp + 16);
	unw_init_from_blocked_task(&info, child);
	if (unw_unwind_to_user(&info) < 0) {
		return -EIO;
	}

	if (((unsigned long) ppr & 0x7) != 0) {
		dprintk("ptrace:unaligned register address %p\n", ppr);
		return -EIO;
	}

	/* control regs */

	retval |= __get_user(pt->cr_iip, &ppr->cr_iip);
	retval |= __get_user(psr, &ppr->cr_ipsr);

	/* app regs */

	retval |= __get_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
	retval |= __get_user(rsc, &ppr->ar[PT_AUR_RSC]);
	retval |= __get_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
	retval |= __get_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
	retval |= __get_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
	retval |= __get_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);

	retval |= __get_user(ec, &ppr->ar[PT_AUR_EC]);
	retval |= __get_user(lc, &ppr->ar[PT_AUR_LC]);
	retval |= __get_user(rnat, &ppr->ar[PT_AUR_RNAT]);
	retval |= __get_user(bsp, &ppr->ar[PT_AUR_BSP]);
	retval |= __get_user(cfm, &ppr->cfm);

	/* gr1-gr3 */

	retval |= __copy_from_user(&pt->r1, &ppr->gr[1], sizeof(long));
	retval |= __copy_from_user(&pt->r2, &ppr->gr[2], sizeof(long) * 2);

	/* gr4-gr7 */

	for (i = 4; i < 8; i++) {
		retval |= __get_user(val, &ppr->gr[i]);
		/* NaT bit will be set via PT_NAT_BITS: */
		if (unw_set_gr(&info, i, val, 0) < 0)
			return -EIO;
	}

	/* gr8-gr11 */

	retval |= __copy_from_user(&pt->r8, &ppr->gr[8], sizeof(long) * 4);

	/* gr12-gr15 */

	retval |= __copy_from_user(&pt->r12, &ppr->gr[12], sizeof(long) * 2);
	retval |= __copy_from_user(&pt->r14, &ppr->gr[14], sizeof(long));
	retval |= __copy_from_user(&pt->r15, &ppr->gr[15], sizeof(long));

	/* gr16-gr31 */

	retval |= __copy_from_user(&pt->r16, &ppr->gr[16], sizeof(long) * 16);

	/* b0 */

	retval |= __get_user(pt->b0, &ppr->br[0]);

	/* b1-b5 */

	for (i = 1; i < 6; i++) {
		retval |= __get_user(val, &ppr->br[i]);
		unw_set_br(&info, i, val);
	}

	/* b6-b7 */

	retval |= __get_user(pt->b6, &ppr->br[6]);
	retval |= __get_user(pt->b7, &ppr->br[7]);

	/* fr2-fr5 */

	for (i = 2; i < 6; i++) {
		retval |= __copy_from_user(&fpval, &ppr->fr[i], sizeof(fpval));
		if (unw_set_fr(&info, i, fpval) < 0)
			return -EIO;
	}

	/* fr6-fr11 */

	retval |= __copy_from_user(&pt->f6, &ppr->fr[6],
				   sizeof(ppr->fr[6]) * 6);

	/* fp scratch regs(12-15) */

	retval |= __copy_from_user(&sw->f12, &ppr->fr[12],
				   sizeof(ppr->fr[12]) * 4);

	/* fr16-fr31 */

	for (i = 16; i < 32; i++) {
		retval |= __copy_from_user(&fpval, &ppr->fr[i],
					   sizeof(fpval));
		if (unw_set_fr(&info, i, fpval) < 0)
			return -EIO;
	}

	/* fph */

	ia64_sync_fph(child);
	retval |= __copy_from_user(&child->thread.fph, &ppr->fr[32],
				   sizeof(ppr->fr[32]) * 96);

	/* preds */

	retval |= __get_user(pt->pr, &ppr->pr);

	/* nat bits */

	retval |= __get_user(nat_bits, &ppr->nat);

	retval |= access_uarea(child, PT_CR_IPSR, &psr, 1);
	retval |= access_uarea(child, PT_AR_RSC, &rsc, 1);
	retval |= access_uarea(child, PT_AR_EC, &ec, 1);
	retval |= access_uarea(child, PT_AR_LC, &lc, 1);
	retval |= access_uarea(child, PT_AR_RNAT, &rnat, 1);
	retval |= access_uarea(child, PT_AR_BSP, &bsp, 1);
	retval |= access_uarea(child, PT_CFM, &cfm, 1);
	retval |= access_uarea(child, PT_NAT_BITS, &nat_bits, 1);

	ret = retval ? -EIO : 0;
	return ret;
}

void
user_enable_single_step (struct task_struct *child)
{
	struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));

	set_tsk_thread_flag(child, TIF_SINGLESTEP);
	child_psr->ss = 1;
}

void
user_enable_block_step (struct task_struct *child)
{
	struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));

	set_tsk_thread_flag(child, TIF_SINGLESTEP);
	child_psr->tb = 1;
}

void
user_disable_single_step (struct task_struct *child)
{
	struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));

	/* make sure the single step/taken-branch trap bits are not set: */
	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
	child_psr->ss = 0;
	child_psr->tb = 0;
}

/*
 * Called by kernel/ptrace.c when detaching..
 *
 * Make sure the single step bit is not set.
 */
void
ptrace_disable (struct task_struct *child)
{
	user_disable_single_step(child);
}

long
arch_ptrace (struct task_struct *child, long request, long addr, long data)
{
	switch (request) {
	case PTRACE_PEEKTEXT:
	case PTRACE_PEEKDATA:
		/* read word at location addr */
		if (access_process_vm(child, addr, &data, sizeof(data), 0)
		    != sizeof(data))
			return -EIO;
		/* ensure return value is not mistaken for error code */
		force_successful_syscall_return();
		return data;

	/* PTRACE_POKETEXT and PTRACE_POKEDATA is handled
	 * by the generic ptrace_request().
	 */

	case PTRACE_PEEKUSR:
		/* read the word at addr in the USER area */
		if (access_uarea(child, addr, &data, 0) < 0)
			return -EIO;
		/* ensure return value is not mistaken for error code */
		force_successful_syscall_return();
		return data;

	case PTRACE_POKEUSR:
		/* write the word at addr in the USER area */
		if (access_uarea(child, addr, &data, 1) < 0)
			return -EIO;
		return 0;

	case PTRACE_OLD_GETSIGINFO:
		/* for backwards-compatibility */
		return ptrace_request(child, PTRACE_GETSIGINFO, addr, data);

	case PTRACE_OLD_SETSIGINFO:
		/* for backwards-compatibility */
		return ptrace_request(child, PTRACE_SETSIGINFO, addr, data);

	case PTRACE_GETREGS:
		return ptrace_getregs(child,
				      (struct pt_all_user_regs __user *) data);

	case PTRACE_SETREGS:
		return ptrace_setregs(child,
				      (struct pt_all_user_regs __user *) data);

	default:
		return ptrace_request(child, request, addr, data);
	}
}


/* "asmlinkage" so the input arguments are preserved... */

asmlinkage long
syscall_trace_enter (long arg0, long arg1, long arg2, long arg3,
		     long arg4, long arg5, long arg6, long arg7,
		     struct pt_regs regs)
{
	if (test_thread_flag(TIF_SYSCALL_TRACE))
		if (tracehook_report_syscall_entry(&regs))
			return -ENOSYS;

	/* copy user rbs to kernel rbs */
	if (test_thread_flag(TIF_RESTORE_RSE))
		ia64_sync_krbs();

	if (unlikely(current->audit_context)) {
		long syscall;
		int arch;

		syscall = regs.r15;
		arch = AUDIT_ARCH_IA64;

		audit_syscall_entry(arch, syscall, arg0, arg1, arg2, arg3);
	}

	return 0;
}

/* "asmlinkage" so the input arguments are preserved... */

asmlinkage void
syscall_trace_leave (long arg0, long arg1, long arg2, long arg3,
		     long arg4, long arg5, long arg6, long arg7,
		     struct pt_regs regs)
{
	int step;

	if (unlikely(current->audit_context)) {
		int success = AUDITSC_RESULT(regs.r10);
		long result = regs.r8;

		if (success != AUDITSC_SUCCESS)
			result = -result;
		audit_syscall_exit(success, result);
	}

	step = test_thread_flag(TIF_SINGLESTEP);
	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
		tracehook_report_syscall_exit(&regs, step);

	/* copy user rbs to kernel rbs */
	if (test_thread_flag(TIF_RESTORE_RSE))
		ia64_sync_krbs();
}

/* Utrace implementation starts here */
struct regset_get {
	void *kbuf;
	void __user *ubuf;
};

struct regset_set {
	const void *kbuf;
	const void __user *ubuf;
};

struct regset_getset {
	struct task_struct *target;
	const struct user_regset *regset;
	union {
		struct regset_get get;
		struct regset_set set;
	} u;
	unsigned int pos;
	unsigned int count;
	int ret;
};

static int
access_elf_gpreg(struct task_struct *target, struct unw_frame_info *info,
		unsigned long addr, unsigned long *data, int write_access)
{
	struct pt_regs *pt;
	unsigned long *ptr = NULL;
	int ret;
	char nat = 0;

	pt = task_pt_regs(target);
	switch (addr) {
	case ELF_GR_OFFSET(1):
		ptr = &pt->r1;
		break;
	case ELF_GR_OFFSET(2):
	case ELF_GR_OFFSET(3):
		ptr = (void *)&pt->r2 + (addr - ELF_GR_OFFSET(2));
		break;
	case ELF_GR_OFFSET(4) ... ELF_GR_OFFSET(7):
		if (write_access) {
			/* read NaT bit first: */
			unsigned long dummy;

			ret = unw_get_gr(info, addr/8, &dummy, &nat);
			if (ret < 0)
				return ret;
		}
		return unw_access_gr(info, addr/8, data, &nat, write_access);
	case ELF_GR_OFFSET(8) ... ELF_GR_OFFSET(11):
		ptr = (void *)&pt->r8 + addr - ELF_GR_OFFSET(8);
		break;
	case ELF_GR_OFFSET(12):
	case ELF_GR_OFFSET(13):
		ptr = (void *)&pt->r12 + addr - ELF_GR_OFFSET(12);
		break;
	case ELF_GR_OFFSET(14):
		ptr = &pt->r14;
		break;
	case ELF_GR_OFFSET(15):
		ptr = &pt->r15;
	}
	if (write_access)
		*ptr = *data;
	else
		*data = *ptr;
	return 0;
}

static int
access_elf_breg(struct task_struct *target, struct unw_frame_info *info,
		unsigned long addr, unsigned long *data, int write_access)
{
	struct pt_regs *pt;
	unsigned long *ptr = NULL;

	pt = task_pt_regs(target);
	switch (addr) {
	case ELF_BR_OFFSET(0):
		ptr = &pt->b0;
		break;
	case ELF_BR_OFFSET(1) ... ELF_BR_OFFSET(5):
		return unw_access_br(info, (addr - ELF_BR_OFFSET(0))/8,
				     data, write_access);
	case ELF_BR_OFFSET(6):
		ptr = &pt->b6;
		break;
	case ELF_BR_OFFSET(7):
		ptr = &pt->b7;
	}
	if (write_access)
		*ptr = *data;
	else
		*data = *ptr;
	return 0;
}

static int
access_elf_areg(struct task_struct *target, struct unw_frame_info *info,
		unsigned long addr, unsigned long *data, int write_access)
{
	struct pt_regs *pt;
	unsigned long cfm, urbs_end;
	unsigned long *ptr = NULL;

	pt = task_pt_regs(target);
	if (addr >= ELF_AR_RSC_OFFSET && addr <= ELF_AR_SSD_OFFSET) {
		switch (addr) {
		case ELF_AR_RSC_OFFSET:
			/* force PL3 */
			if (write_access)
				pt->ar_rsc = *data | (3 << 2);
			else
				*data = pt->ar_rsc;
			return 0;
		case ELF_AR_BSP_OFFSET:
			/*
			 * By convention, we use PT_AR_BSP to refer to
			 * the end of the user-level backing store.
			 * Use ia64_rse_skip_regs(PT_AR_BSP, -CFM.sof)
			 * to get the real value of ar.bsp at the time
			 * the kernel was entered.
			 *
			 * Furthermore, when changing the contents of
			 * PT_AR_BSP (or PT_CFM) while the task is
			 * blocked in a system call, convert the state
			 * so that the non-system-call exit
			 * path is used.  This ensures that the proper
			 * state will be picked up when resuming
			 * execution.  However, it *also* means that
			 * once we write PT_AR_BSP/PT_CFM, it won't be
			 * possible to modify the syscall arguments of
			 * the pending system call any longer.  This
			 * shouldn't be an issue because modifying
			 * PT_AR_BSP/PT_CFM generally implies that
			 * we're either abandoning the pending system
			 * call or that we defer it's re-execution
			 * (e.g., due to GDB doing an inferior
			 * function call).
			 */
			urbs_end = ia64_get_user_rbs_end(target, pt, &cfm);
			if (write_access) {
				if (*data != urbs_end) {
					if (in_syscall(pt))
						convert_to_non_syscall(target,
								       pt,
								       cfm);
					/*
					 * Simulate user-level write
					 * of ar.bsp:
					 */
					pt->loadrs = 0;
					pt->ar_bspstore = *data;
				}
			} else
				*data = urbs_end;
			return 0;
		case ELF_AR_BSPSTORE_OFFSET:
			ptr = &pt->ar_bspstore;
			break;
		case ELF_AR_RNAT_OFFSET:
			ptr = &pt->ar_rnat;
			break;
		case ELF_AR_CCV_OFFSET:
			ptr = &pt->ar_ccv;
			break;
		case ELF_AR_UNAT_OFFSET:
			ptr = &pt->ar_unat;
			break;
		case ELF_AR_FPSR_OFFSET:
			ptr = &pt->ar_fpsr;
			break;
		case ELF_AR_PFS_OFFSET:
			ptr = &pt->ar_pfs;
			break;
		case ELF_AR_LC_OFFSET:
			return unw_access_ar(info, UNW_AR_LC, data,
					     write_access);
		case ELF_AR_EC_OFFSET:
			return unw_access_ar(info, UNW_AR_EC, data,
					     write_access);
		case ELF_AR_CSD_OFFSET:
			ptr = &pt->ar_csd;
			break;
		case ELF_AR_SSD_OFFSET:
			ptr = &pt->ar_ssd;
		}
	} else if (addr >= ELF_CR_IIP_OFFSET && addr <= ELF_CR_IPSR_OFFSET) {
		switch (addr) {
		case ELF_CR_IIP_OFFSET:
			ptr = &pt->cr_iip;
			break;
		case ELF_CFM_OFFSET:
			urbs_end = ia64_get_user_rbs_end(target, pt, &cfm);
			if (write_access) {
				if (((cfm ^ *data) & PFM_MASK) != 0) {
					if (in_syscall(pt))
						convert_to_non_syscall(target,
								       pt,
								       cfm);
					pt->cr_ifs = ((pt->cr_ifs & ~PFM_MASK)
						      | (*data & PFM_MASK));
				}
			} else
				*data = cfm;
			return 0;
		case ELF_CR_IPSR_OFFSET:
			if (write_access) {
				unsigned long tmp = *data;
				/* psr.ri==3 is a reserved value: SDM 2:25 */
				if ((tmp & IA64_PSR_RI) == IA64_PSR_RI)
					tmp &= ~IA64_PSR_RI;
				pt->cr_ipsr = ((tmp & IPSR_MASK)
					       | (pt->cr_ipsr & ~IPSR_MASK));
			} else
				*data = (pt->cr_ipsr & IPSR_MASK);
			return 0;
		}
	} else if (addr == ELF_NAT_OFFSET)
		return access_nat_bits(target, pt, info,
				       data, write_access);
	else if (addr == ELF_PR_OFFSET)
		ptr = &pt->pr;
	else
		return -1;

	if (write_access)
		*ptr = *data;
	else
		*data = *ptr;

	return 0;
}

static int
access_elf_reg(struct task_struct *target, struct unw_frame_info *info,
		unsigned long addr, unsigned long *data, int write_access)
{
	if (addr >= ELF_GR_OFFSET(1) && addr <= ELF_GR_OFFSET(15))
		return access_elf_gpreg(target, info, addr, data, write_access);
	else if (addr >= ELF_BR_OFFSET(0) && addr <= ELF_BR_OFFSET(7))
		return access_elf_breg(target, info, addr, data, write_access);
	else
		return access_elf_areg(target, info, addr, data, write_access);
}

void do_gpregs_get(struct unw_frame_info *info, void *arg)
{
	struct pt_regs *pt;
	struct regset_getset *dst = arg;
	elf_greg_t tmp[16];
	unsigned int i, index, min_copy;

	if (unw_unwind_to_user(info) < 0)
		return;

	/*
	 * coredump format:
	 *      r0-r31
	 *      NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
	 *      predicate registers (p0-p63)
	 *      b0-b7
	 *      ip cfm user-mask
	 *      ar.rsc ar.bsp ar.bspstore ar.rnat
	 *      ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
	 */


	/* Skip r0 */
	if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(1)) {
		dst->ret = user_regset_copyout_zero(&dst->pos, &dst->count,
						      &dst->u.get.kbuf,
						      &dst->u.get.ubuf,
						      0, ELF_GR_OFFSET(1));
		if (dst->ret || dst->count == 0)
			return;
	}

	/* gr1 - gr15 */
	if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(16)) {
		index = (dst->pos - ELF_GR_OFFSET(1)) / sizeof(elf_greg_t);
		min_copy = ELF_GR_OFFSET(16) > (dst->pos + dst->count) ?
			 (dst->pos + dst->count) : ELF_GR_OFFSET(16);
		for (i = dst->pos; i < min_copy; i += sizeof(elf_greg_t),
				index++)
			if (access_elf_reg(dst->target, info, i,
						&tmp[index], 0) < 0) {
				dst->ret = -EIO;
				return;
			}
		dst->ret = user_regset_copyout(&dst->pos, &dst->count,
				&dst->u.get.kbuf, &dst->u.get.ubuf, tmp,
				ELF_GR_OFFSET(1), ELF_GR_OFFSET(16));
		if (dst->ret || dst->count == 0)
			return;
	}

	/* r16-r31 */
	if (dst->count > 0 && dst->pos < ELF_NAT_OFFSET) {
		pt = task_pt_regs(dst->target);
		dst->ret = user_regset_copyout(&dst->pos, &dst->count,
				&dst->u.get.kbuf, &dst->u.get.ubuf, &pt->r16,
				ELF_GR_OFFSET(16), ELF_NAT_OFFSET);
		if (dst->ret || dst->count == 0)
			return;
	}

	/* nat, pr, b0 - b7 */
	if (dst->count > 0 && dst->pos < ELF_CR_IIP_OFFSET) {
		index = (dst->pos - ELF_NAT_OFFSET) / sizeof(elf_greg_t);
		min_copy = ELF_CR_IIP_OFFSET > (dst->pos + dst->count) ?
			 (dst->pos + dst->count) : ELF_CR_IIP_OFFSET;
		for (i = dst->pos; i < min_copy; i += sizeof(elf_greg_t),
				index++)
			if (access_elf_reg(dst->target, info, i,
						&tmp[index], 0) < 0) {
				dst->ret = -EIO;
				return;
			}
		dst->ret = user_regset_copyout(&dst->pos, &dst->count,
				&dst->u.get.kbuf, &dst->u.get.ubuf, tmp,
				ELF_NAT_OFFSET, ELF_CR_IIP_OFFSET);
		if (dst->ret || dst->count == 0)
			return;
	}

	/* ip cfm psr ar.rsc ar.bsp ar.bspstore ar.rnat
	 * ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec ar.csd ar.ssd
	 */
	if (dst->count > 0 && dst->pos < (ELF_AR_END_OFFSET)) {
		index = (dst->pos - ELF_CR_IIP_OFFSET) / sizeof(elf_greg_t);
		min_copy = ELF_AR_END_OFFSET > (dst->pos + dst->count) ?
			 (dst->pos + dst->count) : ELF_AR_END_OFFSET;
		for (i = dst->pos; i < min_copy; i += sizeof(elf_greg_t),
				index++)
			if (access_elf_reg(dst->target, info, i,
						&tmp[index], 0) < 0) {
				dst->ret = -EIO;
				return;
			}
		dst->ret = user_regset_copyout(&dst->pos, &dst->count,
				&dst->u.get.kbuf, &dst->u.get.ubuf, tmp,
				ELF_CR_IIP_OFFSET, ELF_AR_END_OFFSET);
	}
}

void do_gpregs_set(struct unw_frame_info *info, void *arg)
{
	struct pt_regs *pt;
	struct regset_getset *dst = arg;
	elf_greg_t tmp[16];
	unsigned int i, index;

	if (unw_unwind_to_user(info) < 0)
		return;

	/* Skip r0 */
	if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(1)) {
		dst->ret = user_regset_copyin_ignore(&dst->pos, &dst->count,
						       &dst->u.set.kbuf,
						       &dst->u.set.ubuf,
						       0, ELF_GR_OFFSET(1));
		if (dst->ret || dst->count == 0)
			return;
	}

	/* gr1-gr15 */
	if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(16)) {
		i = dst->pos;
		index = (dst->pos - ELF_GR_OFFSET(1)) / sizeof(elf_greg_t);
		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
				&dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
				ELF_GR_OFFSET(1), ELF_GR_OFFSET(16));
		if (dst->ret)
			return;
		for ( ; i < dst->pos; i += sizeof(elf_greg_t), index++)
			if (access_elf_reg(dst->target, info, i,
						&tmp[index], 1) < 0) {
				dst->ret = -EIO;
				return;
			}
		if (dst->count == 0)
			return;
	}

	/* gr16-gr31 */
	if (dst->count > 0 && dst->pos < ELF_NAT_OFFSET) {
		pt = task_pt_regs(dst->target);
		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
				&dst->u.set.kbuf, &dst->u.set.ubuf, &pt->r16,
				ELF_GR_OFFSET(16), ELF_NAT_OFFSET);
		if (dst->ret || dst->count == 0)
			return;
	}

	/* nat, pr, b0 - b7 */
	if (dst->count > 0 && dst->pos < ELF_CR_IIP_OFFSET) {
		i = dst->pos;
		index = (dst->pos - ELF_NAT_OFFSET) / sizeof(elf_greg_t);
		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
				&dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
				ELF_NAT_OFFSET, ELF_CR_IIP_OFFSET);
		if (dst->ret)
			return;
		for (; i < dst->pos; i += sizeof(elf_greg_t), index++)
			if (access_elf_reg(dst->target, info, i,
						&tmp[index], 1) < 0) {
				dst->ret = -EIO;
				return;
			}
		if (dst->count == 0)
			return;
	}

	/* ip cfm psr ar.rsc ar.bsp ar.bspstore ar.rnat
	 * ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec ar.csd ar.ssd
	 */
	if (dst->count > 0 && dst->pos < (ELF_AR_END_OFFSET)) {
		i = dst->pos;
		index = (dst->pos - ELF_CR_IIP_OFFSET) / sizeof(elf_greg_t);
		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
				&dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
				ELF_CR_IIP_OFFSET, ELF_AR_END_OFFSET);
		if (dst->ret)
			return;
		for ( ; i < dst->pos; i += sizeof(elf_greg_t), index++)
			if (access_elf_reg(dst->target, info, i,
						&tmp[index], 1) < 0) {
				dst->ret = -EIO;
				return;
			}
	}
}

#define ELF_FP_OFFSET(i)	(i * sizeof(elf_fpreg_t))

void do_fpregs_get(struct unw_frame_info *info, void *arg)
{
	struct regset_getset *dst = arg;
	struct task_struct *task = dst->target;
	elf_fpreg_t tmp[30];
	int index, min_copy, i;

	if (unw_unwind_to_user(info) < 0)
		return;

	/* Skip pos 0 and 1 */
	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(2)) {
		dst->ret = user_regset_copyout_zero(&dst->pos, &dst->count,
						      &dst->u.get.kbuf,
						      &dst->u.get.ubuf,
						      0, ELF_FP_OFFSET(2));
		if (dst->count == 0 || dst->ret)
			return;
	}

	/* fr2-fr31 */
	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(32)) {
		index = (dst->pos - ELF_FP_OFFSET(2)) / sizeof(elf_fpreg_t);

		min_copy = min(((unsigned int)ELF_FP_OFFSET(32)),
				dst->pos + dst->count);
		for (i = dst->pos; i < min_copy; i += sizeof(elf_fpreg_t),
				index++)
			if (unw_get_fr(info, i / sizeof(elf_fpreg_t),
					 &tmp[index])) {
				dst->ret = -EIO;
				return;
			}
		dst->ret = user_regset_copyout(&dst->pos, &dst->count,
				&dst->u.get.kbuf, &dst->u.get.ubuf, tmp,
				ELF_FP_OFFSET(2), ELF_FP_OFFSET(32));
		if (dst->count == 0 || dst->ret)
			return;
	}

	/* fph */
	if (dst->count > 0) {
		ia64_flush_fph(dst->target);
		if (task->thread.flags & IA64_THREAD_FPH_VALID)
			dst->ret = user_regset_copyout(
				&dst->pos, &dst->count,
				&dst->u.get.kbuf, &dst->u.get.ubuf,
				&dst->target->thread.fph,
				ELF_FP_OFFSET(32), -1);
		else
			/* Zero fill instead.  */
			dst->ret = user_regset_copyout_zero(
				&dst->pos, &dst->count,
				&dst->u.get.kbuf, &dst->u.get.ubuf,
				ELF_FP_OFFSET(32), -1);
	}
}

void do_fpregs_set(struct unw_frame_info *info, void *arg)
{
	struct regset_getset *dst = arg;
	elf_fpreg_t fpreg, tmp[30];
	int index, start, end;

	if (unw_unwind_to_user(info) < 0)
		return;

	/* Skip pos 0 and 1 */
	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(2)) {
		dst->ret = user_regset_copyin_ignore(&dst->pos, &dst->count,
						       &dst->u.set.kbuf,
						       &dst->u.set.ubuf,
						       0, ELF_FP_OFFSET(2));
		if (dst->count == 0 || dst->ret)
			return;
	}

	/* fr2-fr31 */
	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(32)) {
		start = dst->pos;
		end = min(((unsigned int)ELF_FP_OFFSET(32)),
			 dst->pos + dst->count);
		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
				&dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
				ELF_FP_OFFSET(2), ELF_FP_OFFSET(32));
		if (dst->ret)
			return;

		if (start & 0xF) { /* only write high part */
			if (unw_get_fr(info, start / sizeof(elf_fpreg_t),
					 &fpreg)) {
				dst->ret = -EIO;
				return;
			}
			tmp[start / sizeof(elf_fpreg_t) - 2].u.bits[0]
				= fpreg.u.bits[0];
			start &= ~0xFUL;
		}
		if (end & 0xF) { /* only write low part */
			if (unw_get_fr(info, end / sizeof(elf_fpreg_t),
					&fpreg)) {
				dst->ret = -EIO;
				return;
			}
			tmp[end / sizeof(elf_fpreg_t) - 2].u.bits[1]
				= fpreg.u.bits[1];
			end = (end + 0xF) & ~0xFUL;
		}

		for ( ;	start < end ; start += sizeof(elf_fpreg_t)) {
			index = start / sizeof(elf_fpreg_t);
			if (unw_set_fr(info, index, tmp[index - 2])) {
				dst->ret = -EIO;
				return;
			}
		}
		if (dst->ret || dst->count == 0)
			return;
	}

	/* fph */
	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(128)) {
		ia64_sync_fph(dst->target);
		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
						&dst->u.set.kbuf,
						&dst->u.set.ubuf,
						&dst->target->thread.fph,
						ELF_FP_OFFSET(32), -1);
	}
}

static int
do_regset_call(void (*call)(struct unw_frame_info *, void *),
	       struct task_struct *target,
	       const struct user_regset *regset,
	       unsigned int pos, unsigned int count,
	       const void *kbuf, const void __user *ubuf)
{
	struct regset_getset info = { .target = target, .regset = regset,
				 .pos = pos, .count = count,
				 .u.set = { .kbuf = kbuf, .ubuf = ubuf },
				 .ret = 0 };

	if (target == current)
		unw_init_running(call, &info);
	else {
		struct unw_frame_info ufi;
		memset(&ufi, 0, sizeof(ufi));
		unw_init_from_blocked_task(&ufi, target);
		(*call)(&ufi, &info);
	}

	return info.ret;
}

static int
gpregs_get(struct task_struct *target,
	   const struct user_regset *regset,
	   unsigned int pos, unsigned int count,
	   void *kbuf, void __user *ubuf)
{
	return do_regset_call(do_gpregs_get, target, regset, pos, count,
		kbuf, ubuf);
}

static int gpregs_set(struct task_struct *target,
		const struct user_regset *regset,
		unsigned int pos, unsigned int count,
		const void *kbuf, const void __user *ubuf)
{
	return do_regset_call(do_gpregs_set, target, regset, pos, count,
		kbuf, ubuf);
}

static void do_gpregs_writeback(struct unw_frame_info *info, void *arg)
{
	do_sync_rbs(info, ia64_sync_user_rbs);
}

/*
 * This is called to write back the register backing store.
 * ptrace does this before it stops, so that a tracer reading the user
 * memory after the thread stops will get the current register data.
 */
static int
gpregs_writeback(struct task_struct *target,
		 const struct user_regset *regset,
		 int now)
{
	if (test_and_set_tsk_thread_flag(target, TIF_RESTORE_RSE))
		return 0;
	set_notify_resume(target);
	return do_regset_call(do_gpregs_writeback, target, regset, 0, 0,
		NULL, NULL);
}

static int
fpregs_active(struct task_struct *target, const struct user_regset *regset)
{
	return (target->thread.flags & IA64_THREAD_FPH_VALID) ? 128 : 32;
}

static int fpregs_get(struct task_struct *target,
		const struct user_regset *regset,
		unsigned int pos, unsigned int count,
		void *kbuf, void __user *ubuf)
{
	return do_regset_call(do_fpregs_get, target, regset, pos, count,
		kbuf, ubuf);
}

static int fpregs_set(struct task_struct *target,
		const struct user_regset *regset,
		unsigned int pos, unsigned int count,
		const void *kbuf, const void __user *ubuf)
{
	return do_regset_call(do_fpregs_set, target, regset, pos, count,
		kbuf, ubuf);
}

static int
access_uarea(struct task_struct *child, unsigned long addr,
	      unsigned long *data, int write_access)
{
	unsigned int pos = -1; /* an invalid value */
	int ret;
	unsigned long *ptr, regnum;

	if ((addr & 0x7) != 0) {
		dprintk("ptrace: unaligned register address 0x%lx\n", addr);
		return -1;
	}
	if ((addr >= PT_NAT_BITS + 8 && addr < PT_F2) ||
		(addr >= PT_R7 + 8 && addr < PT_B1) ||
		(addr >= PT_AR_LC + 8 && addr < PT_CR_IPSR) ||
		(addr >= PT_AR_SSD + 8 && addr < PT_DBR)) {
		dprintk("ptrace: rejecting access to register "
					"address 0x%lx\n", addr);
		return -1;
	}

	switch (addr) {
	case PT_F32 ... (PT_F127 + 15):
		pos = addr - PT_F32 + ELF_FP_OFFSET(32);
		break;
	case PT_F2 ... (PT_F5 + 15):
		pos = addr - PT_F2 + ELF_FP_OFFSET(2);
		break;
	case PT_F10 ... (PT_F31 + 15):
		pos = addr - PT_F10 + ELF_FP_OFFSET(10);
		break;
	case PT_F6 ... (PT_F9 + 15):
		pos = addr - PT_F6 + ELF_FP_OFFSET(6);
		break;
	}

	if (pos != -1) {
		if (write_access)
			ret = fpregs_set(child, NULL, pos,
				sizeof(unsigned long), data, NULL);
		else
			ret = fpregs_get(child, NULL, pos,
				sizeof(unsigned long), data, NULL);
		if (ret != 0)
			return -1;
		return 0;
	}

	switch (addr) {
	case PT_NAT_BITS:
		pos = ELF_NAT_OFFSET;
		break;
	case PT_R4 ... PT_R7:
		pos = addr - PT_R4 + ELF_GR_OFFSET(4);
		break;
	case PT_B1 ... PT_B5:
		pos = addr - PT_B1 + ELF_BR_OFFSET(1);
		break;
	case PT_AR_EC:
		pos = ELF_AR_EC_OFFSET;
		break;
	case PT_AR_LC:
		pos = ELF_AR_LC_OFFSET;
		break;
	case PT_CR_IPSR:
		pos = ELF_CR_IPSR_OFFSET;
		break;
	case PT_CR_IIP:
		pos = ELF_CR_IIP_OFFSET;
		break;
	case PT_CFM:
		pos = ELF_CFM_OFFSET;
		break;
	case PT_AR_UNAT:
		pos = ELF_AR_UNAT_OFFSET;
		break;
	case PT_AR_PFS:
		pos = ELF_AR_PFS_OFFSET;
		break;
	case PT_AR_RSC:
		pos = ELF_AR_RSC_OFFSET;
		break;
	case PT_AR_RNAT:
		pos = ELF_AR_RNAT_OFFSET;
		break;
	case PT_AR_BSPSTORE:
		pos = ELF_AR_BSPSTORE_OFFSET;
		break;
	case PT_PR:
		pos = ELF_PR_OFFSET;
		break;
	case PT_B6:
		pos = ELF_BR_OFFSET(6);
		break;
	case PT_AR_BSP:
		pos = ELF_AR_BSP_OFFSET;
		break;
	case PT_R1 ... PT_R3:
		pos = addr - PT_R1 + ELF_GR_OFFSET(1);
		break;
	case PT_R12 ... PT_R15:
		pos = addr - PT_R12 + ELF_GR_OFFSET(12);
		break;
	case PT_R8 ... PT_R11:
		pos = addr - PT_R8 + ELF_GR_OFFSET(8);
		break;
	case PT_R16 ... PT_R31:
		pos = addr - PT_R16 + ELF_GR_OFFSET(16);
		break;
	case PT_AR_CCV:
		pos = ELF_AR_CCV_OFFSET;
		break;
	case PT_AR_FPSR:
		pos = ELF_AR_FPSR_OFFSET;
		break;
	case PT_B0:
		pos = ELF_BR_OFFSET(0);
		break;
	case PT_B7:
		pos = ELF_BR_OFFSET(7);
		break;
	case PT_AR_CSD:
		pos = ELF_AR_CSD_OFFSET;
		break;
	case PT_AR_SSD:
		pos = ELF_AR_SSD_OFFSET;
		break;
	}

	if (pos != -1) {
		if (write_access)
			ret = gpregs_set(child, NULL, pos,
				sizeof(unsigned long), data, NULL);
		else
			ret = gpregs_get(child, NULL, pos,
				sizeof(unsigned long), data, NULL);
		if (ret != 0)
			return -1;
		return 0;
	}

	/* access debug registers */
	if (addr >= PT_IBR) {
		regnum = (addr - PT_IBR) >> 3;
		ptr = &child->thread.ibr[0];
	} else {
		regnum = (addr - PT_DBR) >> 3;
		ptr = &child->thread.dbr[0];
	}

	if (regnum >= 8) {
		dprintk("ptrace: rejecting access to register "
				"address 0x%lx\n", addr);
		return -1;
	}
#ifdef CONFIG_PERFMON
	/*
	 * Check if debug registers are used by perfmon. This
	 * test must be done once we know that we can do the
	 * operation, i.e. the arguments are all valid, but
	 * before we start modifying the state.
	 *
	 * Perfmon needs to keep a count of how many processes
	 * are trying to modify the debug registers for system
	 * wide monitoring sessions.
	 *
	 * We also include read access here, because they may
	 * cause the PMU-installed debug register state
	 * (dbr[], ibr[]) to be reset. The two arrays are also
	 * used by perfmon, but we do not use
	 * IA64_THREAD_DBG_VALID. The registers are restored
	 * by the PMU context switch code.
	 */
	if (pfm_use_debug_registers(child))
		return -1;
#endif

	if (!(child->thread.flags & IA64_THREAD_DBG_VALID)) {
		child->thread.flags |= IA64_THREAD_DBG_VALID;
		memset(child->thread.dbr, 0,
				sizeof(child->thread.dbr));
		memset(child->thread.ibr, 0,
				sizeof(child->thread.ibr));
	}

	ptr += regnum;

	if ((regnum & 1) && write_access) {
		/* don't let the user set kernel-level breakpoints: */
		*ptr = *data & ~(7UL << 56);
		return 0;
	}
	if (write_access)
		*ptr = *data;
	else
		*data = *ptr;
	return 0;
}

static const struct user_regset native_regsets[] = {
	{
		.core_note_type = NT_PRSTATUS,
		.n = ELF_NGREG,
		.size = sizeof(elf_greg_t), .align = sizeof(elf_greg_t),
		.get = gpregs_get, .set = gpregs_set,
		.writeback = gpregs_writeback
	},
	{
		.core_note_type = NT_PRFPREG,
		.n = ELF_NFPREG,
		.size = sizeof(elf_fpreg_t), .align = sizeof(elf_fpreg_t),
		.get = fpregs_get, .set = fpregs_set, .active = fpregs_active
	},
};

static const struct user_regset_view user_ia64_view = {
	.name = "ia64",
	.e_machine = EM_IA_64,
	.regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
};

const struct user_regset_view *task_user_regset_view(struct task_struct *tsk)
{
	return &user_ia64_view;
}

struct syscall_get_set_args {
	unsigned int i;
	unsigned int n;
	unsigned long *args;
	struct pt_regs *regs;
	int rw;
};

static void syscall_get_set_args_cb(struct unw_frame_info *info, void *data)
{
	struct syscall_get_set_args *args = data;
	struct pt_regs *pt = args->regs;
	unsigned long *krbs, cfm, ndirty;
	int i, count;

	if (unw_unwind_to_user(info) < 0)
		return;

	cfm = pt->cr_ifs;
	krbs = (unsigned long *)info->task + IA64_RBS_OFFSET/8;
	ndirty = ia64_rse_num_regs(krbs, krbs + (pt->loadrs >> 19));

	count = 0;
	if (in_syscall(pt))
		count = min_t(int, args->n, cfm & 0x7f);

	for (i = 0; i < count; i++) {
		if (args->rw)
			*ia64_rse_skip_regs(krbs, ndirty + i + args->i) =
				args->args[i];
		else
			args->args[i] = *ia64_rse_skip_regs(krbs,
				ndirty + i + args->i);
	}

	if (!args->rw) {
		while (i < args->n) {
			args->args[i] = 0;
			i++;
		}
	}
}

void ia64_syscall_get_set_arguments(struct task_struct *task,
	struct pt_regs *regs, unsigned int i, unsigned int n,
	unsigned long *args, int rw)
{
	struct syscall_get_set_args data = {
		.i = i,
		.n = n,
		.args = args,
		.regs = regs,
		.rw = rw,
	};

	if (task == current)
		unw_init_running(syscall_get_set_args_cb, &data);
	else {
		struct unw_frame_info ufi;
		memset(&ufi, 0, sizeof(ufi));
		unw_init_from_blocked_task(&ufi, task);
		syscall_get_set_args_cb(&ufi, &data);
	}
}