arch/ia64/kernel/ptrace.c

   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/mm.h>
  15 #include <linux/errno.h>
  16 #include <linux/ptrace.h>
  17 #include <linux/user.h>
  18 #include <linux/security.h>
  19 #include <linux/audit.h>
  20 #include <linux/signal.h>
  21 #include <linux/regset.h>
  22 #include <linux/elf.h>
  23 #include <linux/tracehook.h>
  24
  25 #include <asm/pgtable.h>
  26 #include <asm/processor.h>
  27 #include <asm/ptrace_offsets.h>
  28 #include <asm/rse.h>
  29 #include <asm/uaccess.h>
  30 #include <asm/unwind.h>
  31 #ifdef CONFIG_PERFMON
  32 #include <asm/perfmon.h>
  33 #endif
  34
  35 #include "entry.h"
  36
  37 /*
  38  * Bits in the PSR that we allow ptrace() to change:
  39  *      be, up, ac, mfl, mfh (the user mask; five bits total)
  40  *      db (debug breakpoint fault; one bit)
  41  *      id (instruction debug fault disable; one bit)
  42  *      dd (data debug fault disable; one bit)
  43  *      ri (restart instruction; two bits)
  44  *      is (instruction set; one bit)
  45  */
  46 #define IPSR_MASK (IA64_PSR_UM | IA64_PSR_DB | IA64_PSR_IS      \
  47                    | IA64_PSR_ID | IA64_PSR_DD | IA64_PSR_RI)
  48
  49 #define MASK(nbits)     ((1UL << (nbits)) - 1)  /* mask with NBITS bits set */
  50 #define PFM_MASK        MASK(38)
  51
  52 #define PTRACE_DEBUG    0
  53
  54 #if PTRACE_DEBUG
  55 # define dprintk(format...)     printk(format)
  56 # define inline
  57 #else
  58 # define dprintk(format...)
  59 #endif
  60
  61 /* Return TRUE if PT was created due to kernel-entry via a system-call.  */
  62
  63 static inline int
  64 in_syscall (struct pt_regs *pt)
  65 {
  66         return (long) pt->cr_ifs >= 0;
  67 }
  68
  69 /*
  70  * Collect the NaT bits for r1-r31 from scratch_unat and return a NaT
  71  * bitset where bit i is set iff the NaT bit of register i is set.
  72  */
  73 unsigned long
  74 ia64_get_scratch_nat_bits (struct pt_regs *pt, unsigned long scratch_unat)
  75 {
  76 #       define GET_BITS(first, last, unat)                              \
  77         ({                                                              \
  78                 unsigned long bit = ia64_unat_pos(&pt->r##first);       \
  79                 unsigned long nbits = (last - first + 1);               \
  80                 unsigned long mask = MASK(nbits) << first;              \
  81                 unsigned long dist;                                     \
  82                 if (bit < first)                                        \
  83                         dist = 64 + bit - first;                        \
  84                 else                                                    \
  85                         dist = bit - first;                             \
  86                 ia64_rotr(unat, dist) & mask;                           \
  87         })
  88         unsigned long val;
  89
  90         /*
  91          * Registers that are stored consecutively in struct pt_regs
  92          * can be handled in parallel.  If the register order in
  93          * struct_pt_regs changes, this code MUST be updated.
  94          */
  95         val  = GET_BITS( 1,  1, scratch_unat);
  96         val |= GET_BITS( 2,  3, scratch_unat);
  97         val |= GET_BITS(12, 13, scratch_unat);
  98         val |= GET_BITS(14, 14, scratch_unat);
  99         val |= GET_BITS(15, 15, scratch_unat);
 100         val |= GET_BITS( 8, 11, scratch_unat);
 101         val |= GET_BITS(16, 31, scratch_unat);
 102         return val;
 103
 104 #       undef GET_BITS
 105 }
 106
 107 /*
 108  * Set the NaT bits for the scratch registers according to NAT and
 109  * return the resulting unat (assuming the scratch registers are
 110  * stored in PT).
 111  */
 112 unsigned long
 113 ia64_put_scratch_nat_bits (struct pt_regs *pt, unsigned long nat)
 114 {
 115 #       define PUT_BITS(first, last, nat)                               \
 116         ({                                                              \
 117                 unsigned long bit = ia64_unat_pos(&pt->r##first);       \
 118                 unsigned long nbits = (last - first + 1);               \
 119                 unsigned long mask = MASK(nbits) << first;              \
 120                 long dist;                                              \
 121                 if (bit < first)                                        \
 122                         dist = 64 + bit - first;                        \
 123                 else                                                    \
 124                         dist = bit - first;                             \
 125                 ia64_rotl(nat & mask, dist);                            \
 126         })
 127         unsigned long scratch_unat;
 128
 129         /*
 130          * Registers that are stored consecutively in struct pt_regs
 131          * can be handled in parallel.  If the register order in
 132          * struct_pt_regs changes, this code MUST be updated.
 133          */
 134         scratch_unat  = PUT_BITS( 1,  1, nat);
 135         scratch_unat |= PUT_BITS( 2,  3, nat);
 136         scratch_unat |= PUT_BITS(12, 13, nat);
 137         scratch_unat |= PUT_BITS(14, 14, nat);
 138         scratch_unat |= PUT_BITS(15, 15, nat);
 139         scratch_unat |= PUT_BITS( 8, 11, nat);
 140         scratch_unat |= PUT_BITS(16, 31, nat);
 141
 142         return scratch_unat;
 143
 144 #       undef PUT_BITS
 145 }
 146
 147 #define IA64_MLX_TEMPLATE       0x2
 148 #define IA64_MOVL_OPCODE        6
 149
 150 void
 151 ia64_increment_ip (struct pt_regs *regs)
 152 {
 153         unsigned long w0, ri = ia64_psr(regs)->ri + 1;
 154
 155         if (ri > 2) {
 156                 ri = 0;
 157                 regs->cr_iip += 16;
 158         } else if (ri == 2) {
 159                 get_user(w0, (char __user *) regs->cr_iip + 0);
 160                 if (((w0 >> 1) & 0xf) == IA64_MLX_TEMPLATE) {
 161                         /*
 162                          * rfi'ing to slot 2 of an MLX bundle causes
 163                          * an illegal operation fault.  We don't want
 164                          * that to happen...
 165                          */
 166                         ri = 0;
 167                         regs->cr_iip += 16;
 168                 }
 169         }
 170         ia64_psr(regs)->ri = ri;
 171 }
 172
 173 void
 174 ia64_decrement_ip (struct pt_regs *regs)
 175 {
 176         unsigned long w0, ri = ia64_psr(regs)->ri - 1;
 177
 178         if (ia64_psr(regs)->ri == 0) {
 179                 regs->cr_iip -= 16;
 180                 ri = 2;
 181                 get_user(w0, (char __user *) regs->cr_iip + 0);
 182                 if (((w0 >> 1) & 0xf) == IA64_MLX_TEMPLATE) {
 183                         /*
 184                          * rfi'ing to slot 2 of an MLX bundle causes
 185                          * an illegal operation fault.  We don't want
 186                          * that to happen...
 187                          */
 188                         ri = 1;
 189                 }
 190         }
 191         ia64_psr(regs)->ri = ri;
 192 }
 193
 194 /*
 195  * This routine is used to read an rnat bits that are stored on the
 196  * kernel backing store.  Since, in general, the alignment of the user
 197  * and kernel are different, this is not completely trivial.  In
 198  * essence, we need to construct the user RNAT based on up to two
 199  * kernel RNAT values and/or the RNAT value saved in the child's
 200  * pt_regs.
 201  *
 202  * user rbs
 203  *
 204  * +--------+ <-- lowest address
 205  * | slot62 |
 206  * +--------+
 207  * |  rnat  | 0x....1f8
 208  * +--------+
 209  * | slot00 | \
 210  * +--------+ |
 211  * | slot01 | > child_regs->ar_rnat
 212  * +--------+ |
 213  * | slot02 | /                         kernel rbs
 214  * +--------+                           +--------+
 215  *          <- child_regs->ar_bspstore  | slot61 | <-- krbs
 216  * +- - - - +                           +--------+
 217  *                                      | slot62 |
 218  * +- - - - +                           +--------+
 219  *                                      |  rnat  |
 220  * +- - - - +                           +--------+
 221  *   vrnat                              | slot00 |
 222  * +- - - - +                           +--------+
 223  *                                      =        =
 224  *                                      +--------+
 225  *                                      | slot00 | \
 226  *                                      +--------+ |
 227  *                                      | slot01 | > child_stack->ar_rnat
 228  *                                      +--------+ |
 229  *                                      | slot02 | /
 230  *                                      +--------+
 231  *                                                <--- child_stack->ar_bspstore
 232  *
 233  * The way to think of this code is as follows: bit 0 in the user rnat
 234  * corresponds to some bit N (0 <= N <= 62) in one of the kernel rnat
 235  * value.  The kernel rnat value holding this bit is stored in
 236  * variable rnat0.  rnat1 is loaded with the kernel rnat value that
 237  * form the upper bits of the user rnat value.
 238  *
 239  * Boundary cases:
 240  *
 241  * o when reading the rnat "below" the first rnat slot on the kernel
 242  *   backing store, rnat0/rnat1 are set to 0 and the low order bits are
 243  *   merged in from pt->ar_rnat.
 244  *
 245  * o when reading the rnat "above" the last rnat slot on the kernel
 246  *   backing store, rnat0/rnat1 gets its value from sw->ar_rnat.
 247  */
 248 static unsigned long
 249 get_rnat (struct task_struct *task, struct switch_stack *sw,
 250           unsigned long *krbs, unsigned long *urnat_addr,
 251           unsigned long *urbs_end)
 252 {
 253         unsigned long rnat0 = 0, rnat1 = 0, urnat = 0, *slot0_kaddr;
 254         unsigned long umask = 0, mask, m;
 255         unsigned long *kbsp, *ubspstore, *rnat0_kaddr, *rnat1_kaddr, shift;
 256         long num_regs, nbits;
 257         struct pt_regs *pt;
 258
 259         pt = task_pt_regs(task);
 260         kbsp = (unsigned long *) sw->ar_bspstore;
 261         ubspstore = (unsigned long *) pt->ar_bspstore;
 262
 263         if (urbs_end < urnat_addr)
 264                 nbits = ia64_rse_num_regs(urnat_addr - 63, urbs_end);
 265         else
 266                 nbits = 63;
 267         mask = MASK(nbits);
 268         /*
 269          * First, figure out which bit number slot 0 in user-land maps
 270          * to in the kernel rnat.  Do this by figuring out how many
 271          * register slots we're beyond the user's backingstore and
 272          * then computing the equivalent address in kernel space.
 273          */
 274         num_regs = ia64_rse_num_regs(ubspstore, urnat_addr + 1);
 275         slot0_kaddr = ia64_rse_skip_regs(krbs, num_regs);
 276         shift = ia64_rse_slot_num(slot0_kaddr);
 277         rnat1_kaddr = ia64_rse_rnat_addr(slot0_kaddr);
 278         rnat0_kaddr = rnat1_kaddr - 64;
 279
 280         if (ubspstore + 63 > urnat_addr) {
 281                 /* some bits need to be merged in from pt->ar_rnat */
 282                 umask = MASK(ia64_rse_slot_num(ubspstore)) & mask;
 283                 urnat = (pt->ar_rnat & umask);
 284                 mask &= ~umask;
 285                 if (!mask)
 286                         return urnat;
 287         }
 288
 289         m = mask << shift;
 290         if (rnat0_kaddr >= kbsp)
 291                 rnat0 = sw->ar_rnat;
 292         else if (rnat0_kaddr > krbs)
 293                 rnat0 = *rnat0_kaddr;
 294         urnat |= (rnat0 & m) >> shift;
 295
 296         m = mask >> (63 - shift);
 297         if (rnat1_kaddr >= kbsp)
 298                 rnat1 = sw->ar_rnat;
 299         else if (rnat1_kaddr > krbs)
 300                 rnat1 = *rnat1_kaddr;
 301         urnat |= (rnat1 & m) << (63 - shift);
 302         return urnat;
 303 }
 304
 305 /*
 306  * The reverse of get_rnat.
 307  */
 308 static void
 309 put_rnat (struct task_struct *task, struct switch_stack *sw,
 310           unsigned long *krbs, unsigned long *urnat_addr, unsigned long urnat,
 311           unsigned long *urbs_end)
 312 {
 313         unsigned long rnat0 = 0, rnat1 = 0, *slot0_kaddr, umask = 0, mask, m;
 314         unsigned long *kbsp, *ubspstore, *rnat0_kaddr, *rnat1_kaddr, shift;
 315         long num_regs, nbits;
 316         struct pt_regs *pt;
 317         unsigned long cfm, *urbs_kargs;
 318
 319         pt = task_pt_regs(task);
 320         kbsp = (unsigned long *) sw->ar_bspstore;
 321         ubspstore = (unsigned long *) pt->ar_bspstore;
 322
 323         urbs_kargs = urbs_end;
 324         if (in_syscall(pt)) {
 325                 /*
 326                  * If entered via syscall, don't allow user to set rnat bits
 327                  * for syscall args.
 328                  */
 329                 cfm = pt->cr_ifs;
 330                 urbs_kargs = ia64_rse_skip_regs(urbs_end, -(cfm & 0x7f));
 331         }
 332
 333         if (urbs_kargs >= urnat_addr)
 334                 nbits = 63;
 335         else {
 336                 if ((urnat_addr - 63) >= urbs_kargs)
 337                         return;
 338                 nbits = ia64_rse_num_regs(urnat_addr - 63, urbs_kargs);
 339         }
 340         mask = MASK(nbits);
 341
 342         /*
 343          * First, figure out which bit number slot 0 in user-land maps
 344          * to in the kernel rnat.  Do this by figuring out how many
 345          * register slots we're beyond the user's backingstore and
 346          * then computing the equivalent address in kernel space.
 347          */
 348         num_regs = ia64_rse_num_regs(ubspstore, urnat_addr + 1);
 349         slot0_kaddr = ia64_rse_skip_regs(krbs, num_regs);
 350         shift = ia64_rse_slot_num(slot0_kaddr);
 351         rnat1_kaddr = ia64_rse_rnat_addr(slot0_kaddr);
 352         rnat0_kaddr = rnat1_kaddr - 64;
 353
 354         if (ubspstore + 63 > urnat_addr) {
 355                 /* some bits need to be place in pt->ar_rnat: */
 356                 umask = MASK(ia64_rse_slot_num(ubspstore)) & mask;
 357                 pt->ar_rnat = (pt->ar_rnat & ~umask) | (urnat & umask);
 358                 mask &= ~umask;
 359                 if (!mask)
 360                         return;
 361         }
 362         /*
 363          * Note: Section 11.1 of the EAS guarantees that bit 63 of an
 364          * rnat slot is ignored. so we don't have to clear it here.
 365          */
 366         rnat0 = (urnat << shift);
 367         m = mask << shift;
 368         if (rnat0_kaddr >= kbsp)
 369                 sw->ar_rnat = (sw->ar_rnat & ~m) | (rnat0 & m);
 370         else if (rnat0_kaddr > krbs)
 371                 *rnat0_kaddr = ((*rnat0_kaddr & ~m) | (rnat0 & m));
 372
 373         rnat1 = (urnat >> (63 - shift));
 374         m = mask >> (63 - shift);
 375         if (rnat1_kaddr >= kbsp)
 376                 sw->ar_rnat = (sw->ar_rnat & ~m) | (rnat1 & m);
 377         else if (rnat1_kaddr > krbs)
 378                 *rnat1_kaddr = ((*rnat1_kaddr & ~m) | (rnat1 & m));
 379 }
 380
 381 static inline int
 382 on_kernel_rbs (unsigned long addr, unsigned long bspstore,
 383                unsigned long urbs_end)
 384 {
 385         unsigned long *rnat_addr = ia64_rse_rnat_addr((unsigned long *)
 386                                                       urbs_end);
 387         return (addr >= bspstore && addr <= (unsigned long) rnat_addr);
 388 }
 389
 390 /*
 391  * Read a word from the user-level backing store of task CHILD.  ADDR
 392  * is the user-level address to read the word from, VAL a pointer to
 393  * the return value, and USER_BSP gives the end of the user-level
 394  * backing store (i.e., it's the address that would be in ar.bsp after
 395  * the user executed a "cover" instruction).
 396  *
 397  * This routine takes care of accessing the kernel register backing
 398  * store for those registers that got spilled there.  It also takes
 399  * care of calculating the appropriate RNaT collection words.
 400  */
 401 long
 402 ia64_peek (struct task_struct *child, struct switch_stack *child_stack,
 403            unsigned long user_rbs_end, unsigned long addr, long *val)
 404 {
 405         unsigned long *bspstore, *krbs, regnum, *laddr, *urbs_end, *rnat_addr;
 406         struct pt_regs *child_regs;
 407         size_t copied;
 408         long ret;
 409
 410         urbs_end = (long *) user_rbs_end;
 411         laddr = (unsigned long *) addr;
 412         child_regs = task_pt_regs(child);
 413         bspstore = (unsigned long *) child_regs->ar_bspstore;
 414         krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
 415         if (on_kernel_rbs(addr, (unsigned long) bspstore,
 416                           (unsigned long) urbs_end))
 417         {
 418                 /*
 419                  * Attempt to read the RBS in an area that's actually
 420                  * on the kernel RBS => read the corresponding bits in
 421                  * the kernel RBS.
 422                  */
 423                 rnat_addr = ia64_rse_rnat_addr(laddr);
 424                 ret = get_rnat(child, child_stack, krbs, rnat_addr, urbs_end);
 425
 426                 if (laddr == rnat_addr) {
 427                         /* return NaT collection word itself */
 428                         *val = ret;
 429                         return 0;
 430                 }
 431
 432                 if (((1UL << ia64_rse_slot_num(laddr)) & ret) != 0) {
 433                         /*
 434                          * It is implementation dependent whether the
 435                          * data portion of a NaT value gets saved on a
 436                          * st8.spill or RSE spill (e.g., see EAS 2.6,
 437                          * 4.4.4.6 Register Spill and Fill).  To get
 438                          * consistent behavior across all possible
 439                          * IA-64 implementations, we return zero in
 440                          * this case.
 441                          */
 442                         *val = 0;
 443                         return 0;
 444                 }
 445
 446                 if (laddr < urbs_end) {
 447                         /*
 448                          * The desired word is on the kernel RBS and
 449                          * is not a NaT.
 450                          */
 451                         regnum = ia64_rse_num_regs(bspstore, laddr);
 452                         *val = *ia64_rse_skip_regs(krbs, regnum);
 453                         return 0;
 454                 }
 455         }
 456         copied = access_process_vm(child, addr, &ret, sizeof(ret), 0);
 457         if (copied != sizeof(ret))
 458                 return -EIO;
 459         *val = ret;
 460         return 0;
 461 }
 462
 463 long
 464 ia64_poke (struct task_struct *child, struct switch_stack *child_stack,
 465            unsigned long user_rbs_end, unsigned long addr, long val)
 466 {
 467         unsigned long *bspstore, *krbs, regnum, *laddr;
 468         unsigned long *urbs_end = (long *) user_rbs_end;
 469         struct pt_regs *child_regs;
 470
 471         laddr = (unsigned long *) addr;
 472         child_regs = task_pt_regs(child);
 473         bspstore = (unsigned long *) child_regs->ar_bspstore;
 474         krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
 475         if (on_kernel_rbs(addr, (unsigned long) bspstore,
 476                           (unsigned long) urbs_end))
 477         {
 478                 /*
 479                  * Attempt to write the RBS in an area that's actually
 480                  * on the kernel RBS => write the corresponding bits
 481                  * in the kernel RBS.
 482                  */
 483                 if (ia64_rse_is_rnat_slot(laddr))
 484                         put_rnat(child, child_stack, krbs, laddr, val,
 485                                  urbs_end);
 486                 else {
 487                         if (laddr < urbs_end) {
 488                                 regnum = ia64_rse_num_regs(bspstore, laddr);
 489                                 *ia64_rse_skip_regs(krbs, regnum) = val;
 490                         }
 491                 }
 492         } else if (access_process_vm(child, addr, &val, sizeof(val), 1)
 493                    != sizeof(val))
 494                 return -EIO;
 495         return 0;
 496 }
 497
 498 /*
 499  * Calculate the address of the end of the user-level register backing
 500  * store.  This is the address that would have been stored in ar.bsp
 501  * if the user had executed a "cover" instruction right before
 502  * entering the kernel.  If CFMP is not NULL, it is used to return the
 503  * "current frame mask" that was active at the time the kernel was
 504  * entered.
 505  */
 506 unsigned long
 507 ia64_get_user_rbs_end (struct task_struct *child, struct pt_regs *pt,
 508                        unsigned long *cfmp)
 509 {
 510         unsigned long *krbs, *bspstore, cfm = pt->cr_ifs;
 511         long ndirty;
 512
 513         krbs = (unsigned long *) child + IA64_RBS_OFFSET/8;
 514         bspstore = (unsigned long *) pt->ar_bspstore;
 515         ndirty = ia64_rse_num_regs(krbs, krbs + (pt->loadrs >> 19));
 516
 517         if (in_syscall(pt))
 518                 ndirty += (cfm & 0x7f);
 519         else
 520                 cfm &= ~(1UL << 63);    /* clear valid bit */
 521
 522         if (cfmp)
 523                 *cfmp = cfm;
 524         return (unsigned long) ia64_rse_skip_regs(bspstore, ndirty);
 525 }
 526
 527 /*
 528  * Synchronize (i.e, write) the RSE backing store living in kernel
 529  * space to the VM of the CHILD task.  SW and PT are the pointers to
 530  * the switch_stack and pt_regs structures, respectively.
 531  * USER_RBS_END is the user-level address at which the backing store
 532  * ends.
 533  */
 534 long
 535 ia64_sync_user_rbs (struct task_struct *child, struct switch_stack *sw,
 536                     unsigned long user_rbs_start, unsigned long user_rbs_end)
 537 {
 538         unsigned long addr, val;
 539         long ret;
 540
 541         /* now copy word for word from kernel rbs to user rbs: */
 542         for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) {
 543                 ret = ia64_peek(child, sw, user_rbs_end, addr, &val);
 544                 if (ret < 0)
 545                         return ret;
 546                 if (access_process_vm(child, addr, &val, sizeof(val), 1)
 547                     != sizeof(val))
 548                         return -EIO;
 549         }
 550         return 0;
 551 }
 552
 553 static long
 554 ia64_sync_kernel_rbs (struct task_struct *child, struct switch_stack *sw,
 555                 unsigned long user_rbs_start, unsigned long user_rbs_end)
 556 {
 557         unsigned long addr, val;
 558         long ret;
 559
 560         /* now copy word for word from user rbs to kernel rbs: */
 561         for (addr = user_rbs_start; addr < user_rbs_end; addr += 8) {
 562                 if (access_process_vm(child, addr, &val, sizeof(val), 0)
 563                                 != sizeof(val))
 564                         return -EIO;
 565
 566                 ret = ia64_poke(child, sw, user_rbs_end, addr, val);
 567                 if (ret < 0)
 568                         return ret;
 569         }
 570         return 0;
 571 }
 572
 573 typedef long (*syncfunc_t)(struct task_struct *, struct switch_stack *,
 574                             unsigned long, unsigned long);
 575
 576 static void do_sync_rbs(struct unw_frame_info *info, void *arg)
 577 {
 578         struct pt_regs *pt;
 579         unsigned long urbs_end;
 580         syncfunc_t fn = arg;
 581
 582         if (unw_unwind_to_user(info) < 0)
 583                 return;
 584         pt = task_pt_regs(info->task);
 585         urbs_end = ia64_get_user_rbs_end(info->task, pt, NULL);
 586
 587         fn(info->task, info->sw, pt->ar_bspstore, urbs_end);
 588 }
 589
 590 /*
 591  * when a thread is stopped (ptraced), debugger might change thread's user
 592  * stack (change memory directly), and we must avoid the RSE stored in kernel
 593  * to override user stack (user space's RSE is newer than kernel's in the
 594  * case). To workaround the issue, we copy kernel RSE to user RSE before the
 595  * task is stopped, so user RSE has updated data.  we then copy user RSE to
 596  * kernel after the task is resummed from traced stop and kernel will use the
 597  * newer RSE to return to user. TIF_RESTORE_RSE is the flag to indicate we need
 598  * synchronize user RSE to kernel.
 599  */
 600 void ia64_ptrace_stop(void)
 601 {
 602         if (test_and_set_tsk_thread_flag(current, TIF_RESTORE_RSE))
 603                 return;
 604         set_notify_resume(current);
 605         unw_init_running(do_sync_rbs, ia64_sync_user_rbs);
 606 }
 607
 608 /*
 609  * This is called to read back the register backing store.
 610  */
 611 void ia64_sync_krbs(void)
 612 {
 613         clear_tsk_thread_flag(current, TIF_RESTORE_RSE);
 614
 615         unw_init_running(do_sync_rbs, ia64_sync_kernel_rbs);
 616 }
 617
 618 /*
 619  * After PTRACE_ATTACH, a thread's register backing store area in user
 620  * space is assumed to contain correct data whenever the thread is
 621  * stopped.  arch_ptrace_stop takes care of this on tracing stops.
 622  * But if the child was already stopped for job control when we attach
 623  * to it, then it might not ever get into ptrace_stop by the time we
 624  * want to examine the user memory containing the RBS.
 625  */
 626 void
 627 ptrace_attach_sync_user_rbs (struct task_struct *child)
 628 {
 629         int stopped = 0;
 630         struct unw_frame_info info;
 631
 632         /*
 633          * If the child is in TASK_STOPPED, we need to change that to
 634          * TASK_TRACED momentarily while we operate on it.  This ensures
 635          * that the child won't be woken up and return to user mode while
 636          * we are doing the sync.  (It can only be woken up for SIGKILL.)
 637          */
 638
 639         read_lock(&tasklist_lock);
 640         if (child->sighand) {
 641                 spin_lock_irq(&child->sighand->siglock);
 642                 if (child->state == TASK_STOPPED &&
 643                     !test_and_set_tsk_thread_flag(child, TIF_RESTORE_RSE)) {
 644                         set_notify_resume(child);
 645
 646                         child->state = TASK_TRACED;
 647                         stopped = 1;
 648                 }
 649                 spin_unlock_irq(&child->sighand->siglock);
 650         }
 651         read_unlock(&tasklist_lock);
 652
 653         if (!stopped)
 654                 return;
 655
 656         unw_init_from_blocked_task(&info, child);
 657         do_sync_rbs(&info, ia64_sync_user_rbs);
 658
 659         /*
 660          * Now move the child back into TASK_STOPPED if it should be in a
 661          * job control stop, so that SIGCONT can be used to wake it up.
 662          */
 663         read_lock(&tasklist_lock);
 664         if (child->sighand) {
 665                 spin_lock_irq(&child->sighand->siglock);
 666                 if (child->state == TASK_TRACED &&
 667                     (child->signal->flags & SIGNAL_STOP_STOPPED)) {
 668                         child->state = TASK_STOPPED;
 669                 }
 670                 spin_unlock_irq(&child->sighand->siglock);
 671         }
 672         read_unlock(&tasklist_lock);
 673 }
 674
 675 static inline int
 676 thread_matches (struct task_struct *thread, unsigned long addr)
 677 {
 678         unsigned long thread_rbs_end;
 679         struct pt_regs *thread_regs;
 680
 681         if (ptrace_check_attach(thread, 0) < 0)
 682                 /*
 683                  * If the thread is not in an attachable state, we'll
 684                  * ignore it.  The net effect is that if ADDR happens
 685                  * to overlap with the portion of the thread's
 686                  * register backing store that is currently residing
 687                  * on the thread's kernel stack, then ptrace() may end
 688                  * up accessing a stale value.  But if the thread
 689                  * isn't stopped, that's a problem anyhow, so we're
 690                  * doing as well as we can...
 691                  */
 692                 return 0;
 693
 694         thread_regs = task_pt_regs(thread);
 695         thread_rbs_end = ia64_get_user_rbs_end(thread, thread_regs, NULL);
 696         if (!on_kernel_rbs(addr, thread_regs->ar_bspstore, thread_rbs_end))
 697                 return 0;
 698
 699         return 1;       /* looks like we've got a winner */
 700 }
 701
 702 /*
 703  * Write f32-f127 back to task->thread.fph if it has been modified.
 704  */
 705 inline void
 706 ia64_flush_fph (struct task_struct *task)
 707 {
 708         struct ia64_psr *psr = ia64_psr(task_pt_regs(task));
 709
 710         /*
 711          * Prevent migrating this task while
 712          * we're fiddling with the FPU state
 713          */
 714         preempt_disable();
 715         if (ia64_is_local_fpu_owner(task) && psr->mfh) {
 716                 psr->mfh = 0;
 717                 task->thread.flags |= IA64_THREAD_FPH_VALID;
 718                 ia64_save_fpu(&task->thread.fph[0]);
 719         }
 720         preempt_enable();
 721 }
 722
 723 /*
 724  * Sync the fph state of the task so that it can be manipulated
 725  * through thread.fph.  If necessary, f32-f127 are written back to
 726  * thread.fph or, if the fph state hasn't been used before, thread.fph
 727  * is cleared to zeroes.  Also, access to f32-f127 is disabled to
 728  * ensure that the task picks up the state from thread.fph when it
 729  * executes again.
 730  */
 731 void
 732 ia64_sync_fph (struct task_struct *task)
 733 {
 734         struct ia64_psr *psr = ia64_psr(task_pt_regs(task));
 735
 736         ia64_flush_fph(task);
 737         if (!(task->thread.flags & IA64_THREAD_FPH_VALID)) {
 738                 task->thread.flags |= IA64_THREAD_FPH_VALID;
 739                 memset(&task->thread.fph, 0, sizeof(task->thread.fph));
 740         }
 741         ia64_drop_fpu(task);
 742         psr->dfh = 1;
 743 }
 744
 745 /*
 746  * Change the machine-state of CHILD such that it will return via the normal
 747  * kernel exit-path, rather than the syscall-exit path.
 748  */
 749 static void
 750 convert_to_non_syscall (struct task_struct *child, struct pt_regs  *pt,
 751                         unsigned long cfm)
 752 {
 753         struct unw_frame_info info, prev_info;
 754         unsigned long ip, sp, pr;
 755
 756         unw_init_from_blocked_task(&info, child);
 757         while (1) {
 758                 prev_info = info;
 759                 if (unw_unwind(&info) < 0)
 760                         return;
 761
 762                 unw_get_sp(&info, &sp);
 763                 if ((long)((unsigned long)child + IA64_STK_OFFSET - sp)
 764                     < IA64_PT_REGS_SIZE) {
 765                         dprintk("ptrace.%s: ran off the top of the kernel "
 766                                 "stack\n", __func__);
 767                         return;
 768                 }
 769                 if (unw_get_pr (&prev_info, &pr) < 0) {
 770                         unw_get_rp(&prev_info, &ip);
 771                         dprintk("ptrace.%s: failed to read "
 772                                 "predicate register (ip=0x%lx)\n",
 773                                 __func__, ip);
 774                         return;
 775                 }
 776                 if (unw_is_intr_frame(&info)
 777                     && (pr & (1UL << PRED_USER_STACK)))
 778                         break;
 779         }
 780
 781         /*
 782          * Note: at the time of this call, the target task is blocked
 783          * in notify_resume_user() and by clearling PRED_LEAVE_SYSCALL
 784          * (aka, "pLvSys") we redirect execution from
 785          * .work_pending_syscall_end to .work_processed_kernel.
 786          */
 787         unw_get_pr(&prev_info, &pr);
 788         pr &= ~((1UL << PRED_SYSCALL) | (1UL << PRED_LEAVE_SYSCALL));
 789         pr |=  (1UL << PRED_NON_SYSCALL);
 790         unw_set_pr(&prev_info, pr);
 791
 792         pt->cr_ifs = (1UL << 63) | cfm;
 793         /*
 794          * Clear the memory that is NOT written on syscall-entry to
 795          * ensure we do not leak kernel-state to user when execution
 796          * resumes.
 797          */
 798         pt->r2 = 0;
 799         pt->r3 = 0;
 800         pt->r14 = 0;
 801         memset(&pt->r16, 0, 16*8);      /* clear r16-r31 */
 802         memset(&pt->f6, 0, 6*16);       /* clear f6-f11 */
 803         pt->b7 = 0;
 804         pt->ar_ccv = 0;
 805         pt->ar_csd = 0;
 806         pt->ar_ssd = 0;
 807 }
 808
 809 static int
 810 access_nat_bits (struct task_struct *child, struct pt_regs *pt,
 811                  struct unw_frame_info *info,
 812                  unsigned long *data, int write_access)
 813 {
 814         unsigned long regnum, nat_bits, scratch_unat, dummy = 0;
 815         char nat = 0;
 816
 817         if (write_access) {
 818                 nat_bits = *data;
 819                 scratch_unat = ia64_put_scratch_nat_bits(pt, nat_bits);
 820                 if (unw_set_ar(info, UNW_AR_UNAT, scratch_unat) < 0) {
 821                         dprintk("ptrace: failed to set ar.unat\n");
 822                         return -1;
 823                 }
 824                 for (regnum = 4; regnum <= 7; ++regnum) {
 825                         unw_get_gr(info, regnum, &dummy, &nat);
 826                         unw_set_gr(info, regnum, dummy,
 827                                    (nat_bits >> regnum) & 1);
 828                 }
 829         } else {
 830                 if (unw_get_ar(info, UNW_AR_UNAT, &scratch_unat) < 0) {
 831                         dprintk("ptrace: failed to read ar.unat\n");
 832                         return -1;
 833                 }
 834                 nat_bits = ia64_get_scratch_nat_bits(pt, scratch_unat);
 835                 for (regnum = 4; regnum <= 7; ++regnum) {
 836                         unw_get_gr(info, regnum, &dummy, &nat);
 837                         nat_bits |= (nat != 0) << regnum;
 838                 }
 839                 *data = nat_bits;
 840         }
 841         return 0;
 842 }
 843
 844 static int
 845 access_uarea (struct task_struct *child, unsigned long addr,
 846               unsigned long *data, int write_access);
 847
 848 static long
 849 ptrace_getregs (struct task_struct *child, struct pt_all_user_regs __user *ppr)
 850 {
 851         unsigned long psr, ec, lc, rnat, bsp, cfm, nat_bits, val;
 852         struct unw_frame_info info;
 853         struct ia64_fpreg fpval;
 854         struct switch_stack *sw;
 855         struct pt_regs *pt;
 856         long ret, retval = 0;
 857         char nat = 0;
 858         int i;
 859
 860         if (!access_ok(VERIFY_WRITE, ppr, sizeof(struct pt_all_user_regs)))
 861                 return -EIO;
 862
 863         pt = task_pt_regs(child);
 864         sw = (struct switch_stack *) (child->thread.ksp + 16);
 865         unw_init_from_blocked_task(&info, child);
 866         if (unw_unwind_to_user(&info) < 0) {
 867                 return -EIO;
 868         }
 869
 870         if (((unsigned long) ppr & 0x7) != 0) {
 871                 dprintk("ptrace:unaligned register address %p\n", ppr);
 872                 return -EIO;
 873         }
 874
 875         if (access_uarea(child, PT_CR_IPSR, &psr, 0) < 0
 876             || access_uarea(child, PT_AR_EC, &ec, 0) < 0
 877             || access_uarea(child, PT_AR_LC, &lc, 0) < 0
 878             || access_uarea(child, PT_AR_RNAT, &rnat, 0) < 0
 879             || access_uarea(child, PT_AR_BSP, &bsp, 0) < 0
 880             || access_uarea(child, PT_CFM, &cfm, 0)
 881             || access_uarea(child, PT_NAT_BITS, &nat_bits, 0))
 882                 return -EIO;
 883
 884         /* control regs */
 885
 886         retval |= __put_user(pt->cr_iip, &ppr->cr_iip);
 887         retval |= __put_user(psr, &ppr->cr_ipsr);
 888
 889         /* app regs */
 890
 891         retval |= __put_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
 892         retval |= __put_user(pt->ar_rsc, &ppr->ar[PT_AUR_RSC]);
 893         retval |= __put_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
 894         retval |= __put_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
 895         retval |= __put_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
 896         retval |= __put_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);
 897
 898         retval |= __put_user(ec, &ppr->ar[PT_AUR_EC]);
 899         retval |= __put_user(lc, &ppr->ar[PT_AUR_LC]);
 900         retval |= __put_user(rnat, &ppr->ar[PT_AUR_RNAT]);
 901         retval |= __put_user(bsp, &ppr->ar[PT_AUR_BSP]);
 902         retval |= __put_user(cfm, &ppr->cfm);
 903
 904         /* gr1-gr3 */
 905
 906         retval |= __copy_to_user(&ppr->gr[1], &pt->r1, sizeof(long));
 907         retval |= __copy_to_user(&ppr->gr[2], &pt->r2, sizeof(long) *2);
 908
 909         /* gr4-gr7 */
 910
 911         for (i = 4; i < 8; i++) {
 912                 if (unw_access_gr(&info, i, &val, &nat, 0) < 0)
 913                         return -EIO;
 914                 retval |= __put_user(val, &ppr->gr[i]);
 915         }
 916
 917         /* gr8-gr11 */
 918
 919         retval |= __copy_to_user(&ppr->gr[8], &pt->r8, sizeof(long) * 4);
 920
 921         /* gr12-gr15 */
 922
 923         retval |= __copy_to_user(&ppr->gr[12], &pt->r12, sizeof(long) * 2);
 924         retval |= __copy_to_user(&ppr->gr[14], &pt->r14, sizeof(long));
 925         retval |= __copy_to_user(&ppr->gr[15], &pt->r15, sizeof(long));
 926
 927         /* gr16-gr31 */
 928
 929         retval |= __copy_to_user(&ppr->gr[16], &pt->r16, sizeof(long) * 16);
 930
 931         /* b0 */
 932
 933         retval |= __put_user(pt->b0, &ppr->br[0]);
 934
 935         /* b1-b5 */
 936
 937         for (i = 1; i < 6; i++) {
 938                 if (unw_access_br(&info, i, &val, 0) < 0)
 939                         return -EIO;
 940                 __put_user(val, &ppr->br[i]);
 941         }
 942
 943         /* b6-b7 */
 944
 945         retval |= __put_user(pt->b6, &ppr->br[6]);
 946         retval |= __put_user(pt->b7, &ppr->br[7]);
 947
 948         /* fr2-fr5 */
 949
 950         for (i = 2; i < 6; i++) {
 951                 if (unw_get_fr(&info, i, &fpval) < 0)
 952                         return -EIO;
 953                 retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
 954         }
 955
 956         /* fr6-fr11 */
 957
 958         retval |= __copy_to_user(&ppr->fr[6], &pt->f6,
 959                                  sizeof(struct ia64_fpreg) * 6);
 960
 961         /* fp scratch regs(12-15) */
 962
 963         retval |= __copy_to_user(&ppr->fr[12], &sw->f12,
 964                                  sizeof(struct ia64_fpreg) * 4);
 965
 966         /* fr16-fr31 */
 967
 968         for (i = 16; i < 32; i++) {
 969                 if (unw_get_fr(&info, i, &fpval) < 0)
 970                         return -EIO;
 971                 retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
 972         }
 973
 974         /* fph */
 975
 976         ia64_flush_fph(child);
 977         retval |= __copy_to_user(&ppr->fr[32], &child->thread.fph,
 978                                  sizeof(ppr->fr[32]) * 96);
 979
 980         /*  preds */
 981
 982         retval |= __put_user(pt->pr, &ppr->pr);
 983
 984         /* nat bits */
 985
 986         retval |= __put_user(nat_bits, &ppr->nat);
 987
 988         ret = retval ? -EIO : 0;
 989         return ret;
 990 }
 991
 992 static long
 993 ptrace_setregs (struct task_struct *child, struct pt_all_user_regs __user *ppr)
 994 {
 995         unsigned long psr, rsc, ec, lc, rnat, bsp, cfm, nat_bits, val = 0;
 996         struct unw_frame_info info;
 997         struct switch_stack *sw;
 998         struct ia64_fpreg fpval;
 999         struct pt_regs *pt;
1000         long ret, retval = 0;
1001         int i;
1002
1003         memset(&fpval, 0, sizeof(fpval));
1004
1005         if (!access_ok(VERIFY_READ, ppr, sizeof(struct pt_all_user_regs)))
1006                 return -EIO;
1007
1008         pt = task_pt_regs(child);
1009         sw = (struct switch_stack *) (child->thread.ksp + 16);
1010         unw_init_from_blocked_task(&info, child);
1011         if (unw_unwind_to_user(&info) < 0) {
1012                 return -EIO;
1013         }
1014
1015         if (((unsigned long) ppr & 0x7) != 0) {
1016                 dprintk("ptrace:unaligned register address %p\n", ppr);
1017                 return -EIO;
1018         }
1019
1020         /* control regs */
1021
1022         retval |= __get_user(pt->cr_iip, &ppr->cr_iip);
1023         retval |= __get_user(psr, &ppr->cr_ipsr);
1024
1025         /* app regs */
1026
1027         retval |= __get_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
1028         retval |= __get_user(rsc, &ppr->ar[PT_AUR_RSC]);
1029         retval |= __get_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
1030         retval |= __get_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
1031         retval |= __get_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
1032         retval |= __get_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);
1033
1034         retval |= __get_user(ec, &ppr->ar[PT_AUR_EC]);
1035         retval |= __get_user(lc, &ppr->ar[PT_AUR_LC]);
1036         retval |= __get_user(rnat, &ppr->ar[PT_AUR_RNAT]);
1037         retval |= __get_user(bsp, &ppr->ar[PT_AUR_BSP]);
1038         retval |= __get_user(cfm, &ppr->cfm);
1039
1040         /* gr1-gr3 */
1041
1042         retval |= __copy_from_user(&pt->r1, &ppr->gr[1], sizeof(long));
1043         retval |= __copy_from_user(&pt->r2, &ppr->gr[2], sizeof(long) * 2);
1044
1045         /* gr4-gr7 */
1046
1047         for (i = 4; i < 8; i++) {
1048                 retval |= __get_user(val, &ppr->gr[i]);
1049                 /* NaT bit will be set via PT_NAT_BITS: */
1050                 if (unw_set_gr(&info, i, val, 0) < 0)
1051                         return -EIO;
1052         }
1053
1054         /* gr8-gr11 */
1055
1056         retval |= __copy_from_user(&pt->r8, &ppr->gr[8], sizeof(long) * 4);
1057
1058         /* gr12-gr15 */
1059
1060         retval |= __copy_from_user(&pt->r12, &ppr->gr[12], sizeof(long) * 2);
1061         retval |= __copy_from_user(&pt->r14, &ppr->gr[14], sizeof(long));
1062         retval |= __copy_from_user(&pt->r15, &ppr->gr[15], sizeof(long));
1063
1064         /* gr16-gr31 */
1065
1066         retval |= __copy_from_user(&pt->r16, &ppr->gr[16], sizeof(long) * 16);
1067
1068         /* b0 */
1069
1070         retval |= __get_user(pt->b0, &ppr->br[0]);
1071
1072         /* b1-b5 */
1073
1074         for (i = 1; i < 6; i++) {
1075                 retval |= __get_user(val, &ppr->br[i]);
1076                 unw_set_br(&info, i, val);
1077         }
1078
1079         /* b6-b7 */
1080
1081         retval |= __get_user(pt->b6, &ppr->br[6]);
1082         retval |= __get_user(pt->b7, &ppr->br[7]);
1083
1084         /* fr2-fr5 */
1085
1086         for (i = 2; i < 6; i++) {
1087                 retval |= __copy_from_user(&fpval, &ppr->fr[i], sizeof(fpval));
1088                 if (unw_set_fr(&info, i, fpval) < 0)
1089                         return -EIO;
1090         }
1091
1092         /* fr6-fr11 */
1093
1094         retval |= __copy_from_user(&pt->f6, &ppr->fr[6],
1095                                    sizeof(ppr->fr[6]) * 6);
1096
1097         /* fp scratch regs(12-15) */
1098
1099         retval |= __copy_from_user(&sw->f12, &ppr->fr[12],
1100                                    sizeof(ppr->fr[12]) * 4);
1101
1102         /* fr16-fr31 */
1103
1104         for (i = 16; i < 32; i++) {
1105                 retval |= __copy_from_user(&fpval, &ppr->fr[i],
1106                                            sizeof(fpval));
1107                 if (unw_set_fr(&info, i, fpval) < 0)
1108                         return -EIO;
1109         }
1110
1111         /* fph */
1112
1113         ia64_sync_fph(child);
1114         retval |= __copy_from_user(&child->thread.fph, &ppr->fr[32],
1115                                    sizeof(ppr->fr[32]) * 96);
1116
1117         /* preds */
1118
1119         retval |= __get_user(pt->pr, &ppr->pr);
1120
1121         /* nat bits */
1122
1123         retval |= __get_user(nat_bits, &ppr->nat);
1124
1125         retval |= access_uarea(child, PT_CR_IPSR, &psr, 1);
1126         retval |= access_uarea(child, PT_AR_RSC, &rsc, 1);
1127         retval |= access_uarea(child, PT_AR_EC, &ec, 1);
1128         retval |= access_uarea(child, PT_AR_LC, &lc, 1);
1129         retval |= access_uarea(child, PT_AR_RNAT, &rnat, 1);
1130         retval |= access_uarea(child, PT_AR_BSP, &bsp, 1);
1131         retval |= access_uarea(child, PT_CFM, &cfm, 1);
1132         retval |= access_uarea(child, PT_NAT_BITS, &nat_bits, 1);
1133
1134         ret = retval ? -EIO : 0;
1135         return ret;
1136 }
1137
1138 void
1139 user_enable_single_step (struct task_struct *child)
1140 {
1141         struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
1142
1143         set_tsk_thread_flag(child, TIF_SINGLESTEP);
1144         child_psr->ss = 1;
1145 }
1146
1147 void
1148 user_enable_block_step (struct task_struct *child)
1149 {
1150         struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
1151
1152         set_tsk_thread_flag(child, TIF_SINGLESTEP);
1153         child_psr->tb = 1;
1154 }
1155
1156 void
1157 user_disable_single_step (struct task_struct *child)
1158 {
1159         struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
1160
1161         /* make sure the single step/taken-branch trap bits are not set: */
1162         clear_tsk_thread_flag(child, TIF_SINGLESTEP);
1163         child_psr->ss = 0;
1164         child_psr->tb = 0;
1165 }
1166
1167 /*
1168  * Called by kernel/ptrace.c when detaching..
1169  *
1170  * Make sure the single step bit is not set.
1171  */
1172 void
1173 ptrace_disable (struct task_struct *child)
1174 {
1175         user_disable_single_step(child);
1176 }
1177
1178 long
1179 arch_ptrace (struct task_struct *child, long request,
1180              unsigned long addr, unsigned long data)
1181 {
1182         switch (request) {
1183         case PTRACE_PEEKTEXT:
1184         case PTRACE_PEEKDATA:
1185                 /* read word at location addr */
1186                 if (access_process_vm(child, addr, &data, sizeof(data), 0)
1187                     != sizeof(data))
1188                         return -EIO;
1189                 /* ensure return value is not mistaken for error code */
1190                 force_successful_syscall_return();
1191                 return data;
1192
1193         /* PTRACE_POKETEXT and PTRACE_POKEDATA is handled
1194          * by the generic ptrace_request().
1195          */
1196
1197         case PTRACE_PEEKUSR:
1198                 /* read the word at addr in the USER area */
1199                 if (access_uarea(child, addr, &data, 0) < 0)
1200                         return -EIO;
1201                 /* ensure return value is not mistaken for error code */
1202                 force_successful_syscall_return();
1203                 return data;
1204
1205         case PTRACE_POKEUSR:
1206                 /* write the word at addr in the USER area */
1207                 if (access_uarea(child, addr, &data, 1) < 0)
1208                         return -EIO;
1209                 return 0;
1210
1211         case PTRACE_OLD_GETSIGINFO:
1212                 /* for backwards-compatibility */
1213                 return ptrace_request(child, PTRACE_GETSIGINFO, addr, data);
1214
1215         case PTRACE_OLD_SETSIGINFO:
1216                 /* for backwards-compatibility */
1217                 return ptrace_request(child, PTRACE_SETSIGINFO, addr, data);
1218
1219         case PTRACE_GETREGS:
1220                 return ptrace_getregs(child,
1221                                       (struct pt_all_user_regs __user *) data);
1222
1223         case PTRACE_SETREGS:
1224                 return ptrace_setregs(child,
1225                                       (struct pt_all_user_regs __user *) data);
1226
1227         default:
1228                 return ptrace_request(child, request, addr, data);
1229         }
1230 }
1231
1232
1233 /* "asmlinkage" so the input arguments are preserved... */
1234
1235 asmlinkage long
1236 syscall_trace_enter (long arg0, long arg1, long arg2, long arg3,
1237                      long arg4, long arg5, long arg6, long arg7,
1238                      struct pt_regs regs)
1239 {
1240         if (test_thread_flag(TIF_SYSCALL_TRACE))
1241                 if (tracehook_report_syscall_entry(&regs))
1242                         return -ENOSYS;
1243
1244         /* copy user rbs to kernel rbs */
1245         if (test_thread_flag(TIF_RESTORE_RSE))
1246                 ia64_sync_krbs();
1247
1248
1249         audit_syscall_entry(AUDIT_ARCH_IA64, regs.r15, arg0, arg1, arg2, arg3);
1250
1251         return 0;
1252 }
1253
1254 /* "asmlinkage" so the input arguments are preserved... */
1255
1256 asmlinkage void
1257 syscall_trace_leave (long arg0, long arg1, long arg2, long arg3,
1258                      long arg4, long arg5, long arg6, long arg7,
1259                      struct pt_regs regs)
1260 {
1261         int step;
1262
1263         audit_syscall_exit(&regs);
1264
1265         step = test_thread_flag(TIF_SINGLESTEP);
1266         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1267                 tracehook_report_syscall_exit(&regs, step);
1268
1269         /* copy user rbs to kernel rbs */
1270         if (test_thread_flag(TIF_RESTORE_RSE))
1271                 ia64_sync_krbs();
1272 }
1273
1274 /* Utrace implementation starts here */
1275 struct regset_get {
1276         void *kbuf;
1277         void __user *ubuf;
1278 };
1279
1280 struct regset_set {
1281         const void *kbuf;
1282         const void __user *ubuf;
1283 };
1284
1285 struct regset_getset {
1286         struct task_struct *target;
1287         const struct user_regset *regset;
1288         union {
1289                 struct regset_get get;
1290                 struct regset_set set;
1291         } u;
1292         unsigned int pos;
1293         unsigned int count;
1294         int ret;
1295 };
1296
1297 static int
1298 access_elf_gpreg(struct task_struct *target, struct unw_frame_info *info,
1299                 unsigned long addr, unsigned long *data, int write_access)
1300 {
1301         struct pt_regs *pt;
1302         unsigned long *ptr = NULL;
1303         int ret;
1304         char nat = 0;
1305
1306         pt = task_pt_regs(target);
1307         switch (addr) {
1308         case ELF_GR_OFFSET(1):
1309                 ptr = &pt->r1;
1310                 break;
1311         case ELF_GR_OFFSET(2):
1312         case ELF_GR_OFFSET(3):
1313                 ptr = (void *)&pt->r2 + (addr - ELF_GR_OFFSET(2));
1314                 break;
1315         case ELF_GR_OFFSET(4) ... ELF_GR_OFFSET(7):
1316                 if (write_access) {
1317                         /* read NaT bit first: */
1318                         unsigned long dummy;
1319
1320                         ret = unw_get_gr(info, addr/8, &dummy, &nat);
1321                         if (ret < 0)
1322                                 return ret;
1323                 }
1324                 return unw_access_gr(info, addr/8, data, &nat, write_access);
1325         case ELF_GR_OFFSET(8) ... ELF_GR_OFFSET(11):
1326                 ptr = (void *)&pt->r8 + addr - ELF_GR_OFFSET(8);
1327                 break;
1328         case ELF_GR_OFFSET(12):
1329         case ELF_GR_OFFSET(13):
1330                 ptr = (void *)&pt->r12 + addr - ELF_GR_OFFSET(12);
1331                 break;
1332         case ELF_GR_OFFSET(14):
1333                 ptr = &pt->r14;
1334                 break;
1335         case ELF_GR_OFFSET(15):
1336                 ptr = &pt->r15;
1337         }
1338         if (write_access)
1339                 *ptr = *data;
1340         else
1341                 *data = *ptr;
1342         return 0;
1343 }
1344
1345 static int
1346 access_elf_breg(struct task_struct *target, struct unw_frame_info *info,
1347                 unsigned long addr, unsigned long *data, int write_access)
1348 {
1349         struct pt_regs *pt;
1350         unsigned long *ptr = NULL;
1351
1352         pt = task_pt_regs(target);
1353         switch (addr) {
1354         case ELF_BR_OFFSET(0):
1355                 ptr = &pt->b0;
1356                 break;
1357         case ELF_BR_OFFSET(1) ... ELF_BR_OFFSET(5):
1358                 return unw_access_br(info, (addr - ELF_BR_OFFSET(0))/8,
1359                                      data, write_access);
1360         case ELF_BR_OFFSET(6):
1361                 ptr = &pt->b6;
1362                 break;
1363         case ELF_BR_OFFSET(7):
1364                 ptr = &pt->b7;
1365         }
1366         if (write_access)
1367                 *ptr = *data;
1368         else
1369                 *data = *ptr;
1370         return 0;
1371 }
1372
1373 static int
1374 access_elf_areg(struct task_struct *target, struct unw_frame_info *info,
1375                 unsigned long addr, unsigned long *data, int write_access)
1376 {
1377         struct pt_regs *pt;
1378         unsigned long cfm, urbs_end;
1379         unsigned long *ptr = NULL;
1380
1381         pt = task_pt_regs(target);
1382         if (addr >= ELF_AR_RSC_OFFSET && addr <= ELF_AR_SSD_OFFSET) {
1383                 switch (addr) {
1384                 case ELF_AR_RSC_OFFSET:
1385                         /* force PL3 */
1386                         if (write_access)
1387                                 pt->ar_rsc = *data | (3 << 2);
1388                         else
1389                                 *data = pt->ar_rsc;
1390                         return 0;
1391                 case ELF_AR_BSP_OFFSET:
1392                         /*
1393                          * By convention, we use PT_AR_BSP to refer to
1394                          * the end of the user-level backing store.
1395                          * Use ia64_rse_skip_regs(PT_AR_BSP, -CFM.sof)
1396                          * to get the real value of ar.bsp at the time
1397                          * the kernel was entered.
1398                          *
1399                          * Furthermore, when changing the contents of
1400                          * PT_AR_BSP (or PT_CFM) while the task is
1401                          * blocked in a system call, convert the state
1402                          * so that the non-system-call exit
1403                          * path is used.  This ensures that the proper
1404                          * state will be picked up when resuming
1405                          * execution.  However, it *also* means that
1406                          * once we write PT_AR_BSP/PT_CFM, it won't be
1407                          * possible to modify the syscall arguments of
1408                          * the pending system call any longer.  This
1409                          * shouldn't be an issue because modifying
1410                          * PT_AR_BSP/PT_CFM generally implies that
1411                          * we're either abandoning the pending system
1412                          * call or that we defer it's re-execution
1413                          * (e.g., due to GDB doing an inferior
1414                          * function call).
1415                          */
1416                         urbs_end = ia64_get_user_rbs_end(target, pt, &cfm);
1417                         if (write_access) {
1418                                 if (*data != urbs_end) {
1419                                         if (in_syscall(pt))
1420                                                 convert_to_non_syscall(target,
1421                                                                        pt,
1422                                                                        cfm);
1423                                         /*
1424                                          * Simulate user-level write
1425                                          * of ar.bsp:
1426                                          */
1427                                         pt->loadrs = 0;
1428                                         pt->ar_bspstore = *data;
1429                                 }
1430                         } else
1431                                 *data = urbs_end;
1432                         return 0;
1433                 case ELF_AR_BSPSTORE_OFFSET:
1434                         ptr = &pt->ar_bspstore;
1435                         break;
1436                 case ELF_AR_RNAT_OFFSET:
1437                         ptr = &pt->ar_rnat;
1438                         break;
1439                 case ELF_AR_CCV_OFFSET:
1440                         ptr = &pt->ar_ccv;
1441                         break;
1442                 case ELF_AR_UNAT_OFFSET:
1443                         ptr = &pt->ar_unat;
1444                         break;
1445                 case ELF_AR_FPSR_OFFSET:
1446                         ptr = &pt->ar_fpsr;
1447                         break;
1448                 case ELF_AR_PFS_OFFSET:
1449                         ptr = &pt->ar_pfs;
1450                         break;
1451                 case ELF_AR_LC_OFFSET:
1452                         return unw_access_ar(info, UNW_AR_LC, data,
1453                                              write_access);
1454                 case ELF_AR_EC_OFFSET:
1455                         return unw_access_ar(info, UNW_AR_EC, data,
1456                                              write_access);
1457                 case ELF_AR_CSD_OFFSET:
1458                         ptr = &pt->ar_csd;
1459                         break;
1460                 case ELF_AR_SSD_OFFSET:
1461                         ptr = &pt->ar_ssd;
1462                 }
1463         } else if (addr >= ELF_CR_IIP_OFFSET && addr <= ELF_CR_IPSR_OFFSET) {
1464                 switch (addr) {
1465                 case ELF_CR_IIP_OFFSET:
1466                         ptr = &pt->cr_iip;
1467                         break;
1468                 case ELF_CFM_OFFSET:
1469                         urbs_end = ia64_get_user_rbs_end(target, pt, &cfm);
1470                         if (write_access) {
1471                                 if (((cfm ^ *data) & PFM_MASK) != 0) {
1472                                         if (in_syscall(pt))
1473                                                 convert_to_non_syscall(target,
1474                                                                        pt,
1475                                                                        cfm);
1476                                         pt->cr_ifs = ((pt->cr_ifs & ~PFM_MASK)
1477                                                       | (*data & PFM_MASK));
1478                                 }
1479                         } else
1480                                 *data = cfm;
1481                         return 0;
1482                 case ELF_CR_IPSR_OFFSET:
1483                         if (write_access) {
1484                                 unsigned long tmp = *data;
1485                                 /* psr.ri==3 is a reserved value: SDM 2:25 */
1486                                 if ((tmp & IA64_PSR_RI) == IA64_PSR_RI)
1487                                         tmp &= ~IA64_PSR_RI;
1488                                 pt->cr_ipsr = ((tmp & IPSR_MASK)
1489                                                | (pt->cr_ipsr & ~IPSR_MASK));
1490                         } else
1491                                 *data = (pt->cr_ipsr & IPSR_MASK);
1492                         return 0;
1493                 }
1494         } else if (addr == ELF_NAT_OFFSET)
1495                 return access_nat_bits(target, pt, info,
1496                                        data, write_access);
1497         else if (addr == ELF_PR_OFFSET)
1498                 ptr = &pt->pr;
1499         else
1500                 return -1;
1501
1502         if (write_access)
1503                 *ptr = *data;
1504         else
1505                 *data = *ptr;
1506
1507         return 0;
1508 }
1509
1510 static int
1511 access_elf_reg(struct task_struct *target, struct unw_frame_info *info,
1512                 unsigned long addr, unsigned long *data, int write_access)
1513 {
1514         if (addr >= ELF_GR_OFFSET(1) && addr <= ELF_GR_OFFSET(15))
1515                 return access_elf_gpreg(target, info, addr, data, write_access);
1516         else if (addr >= ELF_BR_OFFSET(0) && addr <= ELF_BR_OFFSET(7))
1517                 return access_elf_breg(target, info, addr, data, write_access);
1518         else
1519                 return access_elf_areg(target, info, addr, data, write_access);
1520 }
1521
1522 void do_gpregs_get(struct unw_frame_info *info, void *arg)
1523 {
1524         struct pt_regs *pt;
1525         struct regset_getset *dst = arg;
1526         elf_greg_t tmp[16];
1527         unsigned int i, index, min_copy;
1528
1529         if (unw_unwind_to_user(info) < 0)
1530                 return;
1531
1532         /*
1533          * coredump format:
1534          *      r0-r31
1535          *      NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
1536          *      predicate registers (p0-p63)
1537          *      b0-b7
1538          *      ip cfm user-mask
1539          *      ar.rsc ar.bsp ar.bspstore ar.rnat
1540          *      ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
1541          */
1542
1543
1544         /* Skip r0 */
1545         if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(1)) {
1546                 dst->ret = user_regset_copyout_zero(&dst->pos, &dst->count,
1547                                                       &dst->u.get.kbuf,
1548                                                       &dst->u.get.ubuf,
1549                                                       0, ELF_GR_OFFSET(1));
1550                 if (dst->ret || dst->count == 0)
1551                         return;
1552         }
1553
1554         /* gr1 - gr15 */
1555         if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(16)) {
1556                 index = (dst->pos - ELF_GR_OFFSET(1)) / sizeof(elf_greg_t);
1557                 min_copy = ELF_GR_OFFSET(16) > (dst->pos + dst->count) ?
1558                          (dst->pos + dst->count) : ELF_GR_OFFSET(16);
1559                 for (i = dst->pos; i < min_copy; i += sizeof(elf_greg_t),
1560                                 index++)
1561                         if (access_elf_reg(dst->target, info, i,
1562                                                 &tmp[index], 0) < 0) {
1563                                 dst->ret = -EIO;
1564                                 return;
1565                         }
1566                 dst->ret = user_regset_copyout(&dst->pos, &dst->count,
1567                                 &dst->u.get.kbuf, &dst->u.get.ubuf, tmp,
1568                                 ELF_GR_OFFSET(1), ELF_GR_OFFSET(16));
1569                 if (dst->ret || dst->count == 0)
1570                         return;
1571         }
1572
1573         /* r16-r31 */
1574         if (dst->count > 0 && dst->pos < ELF_NAT_OFFSET) {
1575                 pt = task_pt_regs(dst->target);
1576                 dst->ret = user_regset_copyout(&dst->pos, &dst->count,
1577                                 &dst->u.get.kbuf, &dst->u.get.ubuf, &pt->r16,
1578                                 ELF_GR_OFFSET(16), ELF_NAT_OFFSET);
1579                 if (dst->ret || dst->count == 0)
1580                         return;
1581         }
1582
1583         /* nat, pr, b0 - b7 */
1584         if (dst->count > 0 && dst->pos < ELF_CR_IIP_OFFSET) {
1585                 index = (dst->pos - ELF_NAT_OFFSET) / sizeof(elf_greg_t);
1586                 min_copy = ELF_CR_IIP_OFFSET > (dst->pos + dst->count) ?
1587                          (dst->pos + dst->count) : ELF_CR_IIP_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_NAT_OFFSET, ELF_CR_IIP_OFFSET);
1598                 if (dst->ret || dst->count == 0)
1599                         return;
1600         }
1601
1602         /* ip cfm psr ar.rsc ar.bsp ar.bspstore ar.rnat
1603          * ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec ar.csd ar.ssd
1604          */
1605         if (dst->count > 0 && dst->pos < (ELF_AR_END_OFFSET)) {
1606                 index = (dst->pos - ELF_CR_IIP_OFFSET) / sizeof(elf_greg_t);
1607                 min_copy = ELF_AR_END_OFFSET > (dst->pos + dst->count) ?
1608                          (dst->pos + dst->count) : ELF_AR_END_OFFSET;
1609                 for (i = dst->pos; i < min_copy; i += sizeof(elf_greg_t),
1610                                 index++)
1611                         if (access_elf_reg(dst->target, info, i,
1612                                                 &tmp[index], 0) < 0) {
1613                                 dst->ret = -EIO;
1614                                 return;
1615                         }
1616                 dst->ret = user_regset_copyout(&dst->pos, &dst->count,
1617                                 &dst->u.get.kbuf, &dst->u.get.ubuf, tmp,
1618                                 ELF_CR_IIP_OFFSET, ELF_AR_END_OFFSET);
1619         }
1620 }
1621
1622 void do_gpregs_set(struct unw_frame_info *info, void *arg)
1623 {
1624         struct pt_regs *pt;
1625         struct regset_getset *dst = arg;
1626         elf_greg_t tmp[16];
1627         unsigned int i, index;
1628
1629         if (unw_unwind_to_user(info) < 0)
1630                 return;
1631
1632         /* Skip r0 */
1633         if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(1)) {
1634                 dst->ret = user_regset_copyin_ignore(&dst->pos, &dst->count,
1635                                                        &dst->u.set.kbuf,
1636                                                        &dst->u.set.ubuf,
1637                                                        0, ELF_GR_OFFSET(1));
1638                 if (dst->ret || dst->count == 0)
1639                         return;
1640         }
1641
1642         /* gr1-gr15 */
1643         if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(16)) {
1644                 i = dst->pos;
1645                 index = (dst->pos - ELF_GR_OFFSET(1)) / sizeof(elf_greg_t);
1646                 dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1647                                 &dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
1648                                 ELF_GR_OFFSET(1), ELF_GR_OFFSET(16));
1649                 if (dst->ret)
1650                         return;
1651                 for ( ; i < dst->pos; i += sizeof(elf_greg_t), index++)
1652                         if (access_elf_reg(dst->target, info, i,
1653                                                 &tmp[index], 1) < 0) {
1654                                 dst->ret = -EIO;
1655                                 return;
1656                         }
1657                 if (dst->count == 0)
1658                         return;
1659         }
1660
1661         /* gr16-gr31 */
1662         if (dst->count > 0 && dst->pos < ELF_NAT_OFFSET) {
1663                 pt = task_pt_regs(dst->target);
1664                 dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1665                                 &dst->u.set.kbuf, &dst->u.set.ubuf, &pt->r16,
1666                                 ELF_GR_OFFSET(16), ELF_NAT_OFFSET);
1667                 if (dst->ret || dst->count == 0)
1668                         return;
1669         }
1670
1671         /* nat, pr, b0 - b7 */
1672         if (dst->count > 0 && dst->pos < ELF_CR_IIP_OFFSET) {
1673                 i = dst->pos;
1674                 index = (dst->pos - ELF_NAT_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_NAT_OFFSET, ELF_CR_IIP_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                 if (dst->count == 0)
1687                         return;
1688         }
1689
1690         /* ip cfm psr ar.rsc ar.bsp ar.bspstore ar.rnat
1691          * ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec ar.csd ar.ssd
1692          */
1693         if (dst->count > 0 && dst->pos < (ELF_AR_END_OFFSET)) {
1694                 i = dst->pos;
1695                 index = (dst->pos - ELF_CR_IIP_OFFSET) / sizeof(elf_greg_t);
1696                 dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1697                                 &dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
1698                                 ELF_CR_IIP_OFFSET, ELF_AR_END_OFFSET);
1699                 if (dst->ret)
1700                         return;
1701                 for ( ; i < dst->pos; i += sizeof(elf_greg_t), index++)
1702                         if (access_elf_reg(dst->target, info, i,
1703                                                 &tmp[index], 1) < 0) {
1704                                 dst->ret = -EIO;
1705                                 return;
1706                         }
1707         }
1708 }
1709
1710 #define ELF_FP_OFFSET(i)        (i * sizeof(elf_fpreg_t))
1711
1712 void do_fpregs_get(struct unw_frame_info *info, void *arg)
1713 {
1714         struct regset_getset *dst = arg;
1715         struct task_struct *task = dst->target;
1716         elf_fpreg_t tmp[30];
1717         int index, min_copy, i;
1718
1719         if (unw_unwind_to_user(info) < 0)
1720                 return;
1721
1722         /* Skip pos 0 and 1 */
1723         if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(2)) {
1724                 dst->ret = user_regset_copyout_zero(&dst->pos, &dst->count,
1725                                                       &dst->u.get.kbuf,
1726                                                       &dst->u.get.ubuf,
1727                                                       0, ELF_FP_OFFSET(2));
1728                 if (dst->count == 0 || dst->ret)
1729                         return;
1730         }
1731
1732         /* fr2-fr31 */
1733         if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(32)) {
1734                 index = (dst->pos - ELF_FP_OFFSET(2)) / sizeof(elf_fpreg_t);
1735
1736                 min_copy = min(((unsigned int)ELF_FP_OFFSET(32)),
1737                                 dst->pos + dst->count);
1738                 for (i = dst->pos; i < min_copy; i += sizeof(elf_fpreg_t),
1739                                 index++)
1740                         if (unw_get_fr(info, i / sizeof(elf_fpreg_t),
1741                                          &tmp[index])) {
1742                                 dst->ret = -EIO;
1743                                 return;
1744                         }
1745                 dst->ret = user_regset_copyout(&dst->pos, &dst->count,
1746                                 &dst->u.get.kbuf, &dst->u.get.ubuf, tmp,
1747                                 ELF_FP_OFFSET(2), ELF_FP_OFFSET(32));
1748                 if (dst->count == 0 || dst->ret)
1749                         return;
1750         }
1751
1752         /* fph */
1753         if (dst->count > 0) {
1754                 ia64_flush_fph(dst->target);
1755                 if (task->thread.flags & IA64_THREAD_FPH_VALID)
1756                         dst->ret = user_regset_copyout(
1757                                 &dst->pos, &dst->count,
1758                                 &dst->u.get.kbuf, &dst->u.get.ubuf,
1759                                 &dst->target->thread.fph,
1760                                 ELF_FP_OFFSET(32), -1);
1761                 else
1762                         /* Zero fill instead.  */
1763                         dst->ret = user_regset_copyout_zero(
1764                                 &dst->pos, &dst->count,
1765                                 &dst->u.get.kbuf, &dst->u.get.ubuf,
1766                                 ELF_FP_OFFSET(32), -1);
1767         }
1768 }
1769
1770 void do_fpregs_set(struct unw_frame_info *info, void *arg)
1771 {
1772         struct regset_getset *dst = arg;
1773         elf_fpreg_t fpreg, tmp[30];
1774         int index, start, end;
1775
1776         if (unw_unwind_to_user(info) < 0)
1777                 return;
1778
1779         /* Skip pos 0 and 1 */
1780         if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(2)) {
1781                 dst->ret = user_regset_copyin_ignore(&dst->pos, &dst->count,
1782                                                        &dst->u.set.kbuf,
1783                                                        &dst->u.set.ubuf,
1784                                                        0, ELF_FP_OFFSET(2));
1785                 if (dst->count == 0 || dst->ret)
1786                         return;
1787         }
1788
1789         /* fr2-fr31 */
1790         if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(32)) {
1791                 start = dst->pos;
1792                 end = min(((unsigned int)ELF_FP_OFFSET(32)),
1793                          dst->pos + dst->count);
1794                 dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1795                                 &dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
1796                                 ELF_FP_OFFSET(2), ELF_FP_OFFSET(32));
1797                 if (dst->ret)
1798                         return;
1799
1800                 if (start & 0xF) { /* only write high part */
1801                         if (unw_get_fr(info, start / sizeof(elf_fpreg_t),
1802                                          &fpreg)) {
1803                                 dst->ret = -EIO;
1804                                 return;
1805                         }
1806                         tmp[start / sizeof(elf_fpreg_t) - 2].u.bits[0]
1807                                 = fpreg.u.bits[0];
1808                         start &= ~0xFUL;
1809                 }
1810                 if (end & 0xF) { /* only write low part */
1811                         if (unw_get_fr(info, end / sizeof(elf_fpreg_t),
1812                                         &fpreg)) {
1813                                 dst->ret = -EIO;
1814                                 return;
1815                         }
1816                         tmp[end / sizeof(elf_fpreg_t) - 2].u.bits[1]
1817                                 = fpreg.u.bits[1];
1818                         end = (end + 0xF) & ~0xFUL;
1819                 }
1820
1821                 for ( ; start < end ; start += sizeof(elf_fpreg_t)) {
1822                         index = start / sizeof(elf_fpreg_t);
1823                         if (unw_set_fr(info, index, tmp[index - 2])) {
1824                                 dst->ret = -EIO;
1825                                 return;
1826                         }
1827                 }
1828                 if (dst->ret || dst->count == 0)
1829                         return;
1830         }
1831
1832         /* fph */
1833         if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(128)) {
1834                 ia64_sync_fph(dst->target);
1835                 dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1836                                                 &dst->u.set.kbuf,
1837                                                 &dst->u.set.ubuf,
1838                                                 &dst->target->thread.fph,
1839                                                 ELF_FP_OFFSET(32), -1);
1840         }
1841 }
1842
1843 static int
1844 do_regset_call(void (*call)(struct unw_frame_info *, void *),
1845                struct task_struct *target,
1846                const struct user_regset *regset,
1847                unsigned int pos, unsigned int count,
1848                const void *kbuf, const void __user *ubuf)
1849 {
1850         struct regset_getset info = { .target = target, .regset = regset,
1851                                  .pos = pos, .count = count,
1852                                  .u.set = { .kbuf = kbuf, .ubuf = ubuf },
1853                                  .ret = 0 };
1854
1855         if (target == current)
1856                 unw_init_running(call, &info);
1857         else {
1858                 struct unw_frame_info ufi;
1859                 memset(&ufi, 0, sizeof(ufi));
1860                 unw_init_from_blocked_task(&ufi, target);
1861                 (*call)(&ufi, &info);
1862         }
1863
1864         return info.ret;
1865 }
1866
1867 static int
1868 gpregs_get(struct task_struct *target,
1869            const struct user_regset *regset,
1870            unsigned int pos, unsigned int count,
1871            void *kbuf, void __user *ubuf)
1872 {
1873         return do_regset_call(do_gpregs_get, target, regset, pos, count,
1874                 kbuf, ubuf);
1875 }
1876
1877 static int gpregs_set(struct task_struct *target,
1878                 const struct user_regset *regset,
1879                 unsigned int pos, unsigned int count,
1880                 const void *kbuf, const void __user *ubuf)
1881 {
1882         return do_regset_call(do_gpregs_set, target, regset, pos, count,
1883                 kbuf, ubuf);
1884 }
1885
1886 static void do_gpregs_writeback(struct unw_frame_info *info, void *arg)
1887 {
1888         do_sync_rbs(info, ia64_sync_user_rbs);
1889 }
1890
1891 /*
1892  * This is called to write back the register backing store.
1893  * ptrace does this before it stops, so that a tracer reading the user
1894  * memory after the thread stops will get the current register data.
1895  */
1896 static int
1897 gpregs_writeback(struct task_struct *target,
1898                  const struct user_regset *regset,
1899                  int now)
1900 {
1901         if (test_and_set_tsk_thread_flag(target, TIF_RESTORE_RSE))
1902                 return 0;
1903         set_notify_resume(target);
1904         return do_regset_call(do_gpregs_writeback, target, regset, 0, 0,
1905                 NULL, NULL);
1906 }
1907
1908 static int
1909 fpregs_active(struct task_struct *target, const struct user_regset *regset)
1910 {
1911         return (target->thread.flags & IA64_THREAD_FPH_VALID) ? 128 : 32;
1912 }
1913
1914 static int fpregs_get(struct task_struct *target,
1915                 const struct user_regset *regset,
1916                 unsigned int pos, unsigned int count,
1917                 void *kbuf, void __user *ubuf)
1918 {
1919         return do_regset_call(do_fpregs_get, target, regset, pos, count,
1920                 kbuf, ubuf);
1921 }
1922
1923 static int fpregs_set(struct task_struct *target,
1924                 const struct user_regset *regset,
1925                 unsigned int pos, unsigned int count,
1926                 const void *kbuf, const void __user *ubuf)
1927 {
1928         return do_regset_call(do_fpregs_set, target, regset, pos, count,
1929                 kbuf, ubuf);
1930 }
1931
1932 static int
1933 access_uarea(struct task_struct *child, unsigned long addr,
1934               unsigned long *data, int write_access)
1935 {
1936         unsigned int pos = -1; /* an invalid value */
1937         int ret;
1938         unsigned long *ptr, regnum;
1939
1940         if ((addr & 0x7) != 0) {
1941                 dprintk("ptrace: unaligned register address 0x%lx\n", addr);
1942                 return -1;
1943         }
1944         if ((addr >= PT_NAT_BITS + 8 && addr < PT_F2) ||
1945                 (addr >= PT_R7 + 8 && addr < PT_B1) ||
1946                 (addr >= PT_AR_LC + 8 && addr < PT_CR_IPSR) ||
1947                 (addr >= PT_AR_SSD + 8 && addr < PT_DBR)) {
1948                 dprintk("ptrace: rejecting access to register "
1949                                         "address 0x%lx\n", addr);
1950                 return -1;
1951         }
1952
1953         switch (addr) {
1954         case PT_F32 ... (PT_F127 + 15):
1955                 pos = addr - PT_F32 + ELF_FP_OFFSET(32);
1956                 break;
1957         case PT_F2 ... (PT_F5 + 15):
1958                 pos = addr - PT_F2 + ELF_FP_OFFSET(2);
1959                 break;
1960         case PT_F10 ... (PT_F31 + 15):
1961                 pos = addr - PT_F10 + ELF_FP_OFFSET(10);
1962                 break;
1963         case PT_F6 ... (PT_F9 + 15):
1964                 pos = addr - PT_F6 + ELF_FP_OFFSET(6);
1965                 break;
1966         }
1967
1968         if (pos != -1) {
1969                 if (write_access)
1970                         ret = fpregs_set(child, NULL, pos,
1971                                 sizeof(unsigned long), data, NULL);
1972                 else
1973                         ret = fpregs_get(child, NULL, pos,
1974                                 sizeof(unsigned long), data, NULL);
1975                 if (ret != 0)
1976                         return -1;
1977                 return 0;
1978         }
1979
1980         switch (addr) {
1981         case PT_NAT_BITS:
1982                 pos = ELF_NAT_OFFSET;
1983                 break;
1984         case PT_R4 ... PT_R7:
1985                 pos = addr - PT_R4 + ELF_GR_OFFSET(4);
1986                 break;
1987         case PT_B1 ... PT_B5:
1988                 pos = addr - PT_B1 + ELF_BR_OFFSET(1);
1989                 break;
1990         case PT_AR_EC:
1991                 pos = ELF_AR_EC_OFFSET;
1992                 break;
1993         case PT_AR_LC:
1994                 pos = ELF_AR_LC_OFFSET;
1995                 break;
1996         case PT_CR_IPSR:
1997                 pos = ELF_CR_IPSR_OFFSET;
1998                 break;
1999         case PT_CR_IIP:
2000                 pos = ELF_CR_IIP_OFFSET;
2001                 break;
2002         case PT_CFM:
2003                 pos = ELF_CFM_OFFSET;
2004                 break;
2005         case PT_AR_UNAT:
2006                 pos = ELF_AR_UNAT_OFFSET;
2007                 break;
2008         case PT_AR_PFS:
2009                 pos = ELF_AR_PFS_OFFSET;
2010                 break;
2011         case PT_AR_RSC:
2012                 pos = ELF_AR_RSC_OFFSET;
2013                 break;
2014         case PT_AR_RNAT:
2015                 pos = ELF_AR_RNAT_OFFSET;
2016                 break;
2017         case PT_AR_BSPSTORE:
2018                 pos = ELF_AR_BSPSTORE_OFFSET;
2019                 break;
2020         case PT_PR:
2021                 pos = ELF_PR_OFFSET;
2022                 break;
2023         case PT_B6:
2024                 pos = ELF_BR_OFFSET(6);
2025                 break;
2026         case PT_AR_BSP:
2027                 pos = ELF_AR_BSP_OFFSET;
2028                 break;
2029         case PT_R1 ... PT_R3:
2030                 pos = addr - PT_R1 + ELF_GR_OFFSET(1);
2031                 break;
2032         case PT_R12 ... PT_R15:
2033                 pos = addr - PT_R12 + ELF_GR_OFFSET(12);
2034                 break;
2035         case PT_R8 ... PT_R11:
2036                 pos = addr - PT_R8 + ELF_GR_OFFSET(8);
2037                 break;
2038         case PT_R16 ... PT_R31:
2039                 pos = addr - PT_R16 + ELF_GR_OFFSET(16);
2040                 break;
2041         case PT_AR_CCV:
2042                 pos = ELF_AR_CCV_OFFSET;
2043                 break;
2044         case PT_AR_FPSR:
2045                 pos = ELF_AR_FPSR_OFFSET;
2046                 break;
2047         case PT_B0:
2048                 pos = ELF_BR_OFFSET(0);
2049                 break;
2050         case PT_B7:
2051                 pos = ELF_BR_OFFSET(7);
2052                 break;
2053         case PT_AR_CSD:
2054                 pos = ELF_AR_CSD_OFFSET;
2055                 break;
2056         case PT_AR_SSD:
2057                 pos = ELF_AR_SSD_OFFSET;
2058                 break;
2059         }
2060
2061         if (pos != -1) {
2062                 if (write_access)
2063                         ret = gpregs_set(child, NULL, pos,
2064                                 sizeof(unsigned long), data, NULL);
2065                 else
2066                         ret = gpregs_get(child, NULL, pos,
2067                                 sizeof(unsigned long), data, NULL);
2068                 if (ret != 0)
2069                         return -1;
2070                 return 0;
2071         }
2072
2073         /* access debug registers */
2074         if (addr >= PT_IBR) {
2075                 regnum = (addr - PT_IBR) >> 3;
2076                 ptr = &child->thread.ibr[0];
2077         } else {
2078                 regnum = (addr - PT_DBR) >> 3;
2079                 ptr = &child->thread.dbr[0];
2080         }
2081
2082         if (regnum >= 8) {
2083                 dprintk("ptrace: rejecting access to register "
2084                                 "address 0x%lx\n", addr);
2085                 return -1;
2086         }
2087 #ifdef CONFIG_PERFMON
2088         /*
2089          * Check if debug registers are used by perfmon. This
2090          * test must be done once we know that we can do the
2091          * operation, i.e. the arguments are all valid, but
2092          * before we start modifying the state.
2093          *
2094          * Perfmon needs to keep a count of how many processes
2095          * are trying to modify the debug registers for system
2096          * wide monitoring sessions.
2097          *
2098          * We also include read access here, because they may
2099          * cause the PMU-installed debug register state
2100          * (dbr[], ibr[]) to be reset. The two arrays are also
2101          * used by perfmon, but we do not use
2102          * IA64_THREAD_DBG_VALID. The registers are restored
2103          * by the PMU context switch code.
2104          */
2105         if (pfm_use_debug_registers(child))
2106                 return -1;
2107 #endif
2108
2109         if (!(child->thread.flags & IA64_THREAD_DBG_VALID)) {
2110                 child->thread.flags |= IA64_THREAD_DBG_VALID;
2111                 memset(child->thread.dbr, 0,
2112                                 sizeof(child->thread.dbr));
2113                 memset(child->thread.ibr, 0,
2114                                 sizeof(child->thread.ibr));
2115         }
2116
2117         ptr += regnum;
2118
2119         if ((regnum & 1) && write_access) {
2120                 /* don't let the user set kernel-level breakpoints: */
2121                 *ptr = *data & ~(7UL << 56);
2122                 return 0;
2123         }
2124         if (write_access)
2125                 *ptr = *data;
2126         else
2127                 *data = *ptr;
2128         return 0;
2129 }
2130
2131 static const struct user_regset native_regsets[] = {
2132         {
2133                 .core_note_type = NT_PRSTATUS,
2134                 .n = ELF_NGREG,
2135                 .size = sizeof(elf_greg_t), .align = sizeof(elf_greg_t),
2136                 .get = gpregs_get, .set = gpregs_set,
2137                 .writeback = gpregs_writeback
2138         },
2139         {
2140                 .core_note_type = NT_PRFPREG,
2141                 .n = ELF_NFPREG,
2142                 .size = sizeof(elf_fpreg_t), .align = sizeof(elf_fpreg_t),
2143                 .get = fpregs_get, .set = fpregs_set, .active = fpregs_active
2144         },
2145 };
2146
2147 static const struct user_regset_view user_ia64_view = {
2148         .name = "ia64",
2149         .e_machine = EM_IA_64,
2150         .regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
2151 };
2152
2153 const struct user_regset_view *task_user_regset_view(struct task_struct *tsk)
2154 {
2155         return &user_ia64_view;
2156 }
2157
2158 struct syscall_get_set_args {
2159         unsigned int i;
2160         unsigned int n;
2161         unsigned long *args;
2162         struct pt_regs *regs;
2163         int rw;
2164 };
2165
2166 static void syscall_get_set_args_cb(struct unw_frame_info *info, void *data)
2167 {
2168         struct syscall_get_set_args *args = data;
2169         struct pt_regs *pt = args->regs;
2170         unsigned long *krbs, cfm, ndirty;
2171         int i, count;
2172
2173         if (unw_unwind_to_user(info) < 0)
2174                 return;
2175
2176         cfm = pt->cr_ifs;
2177         krbs = (unsigned long *)info->task + IA64_RBS_OFFSET/8;
2178         ndirty = ia64_rse_num_regs(krbs, krbs + (pt->loadrs >> 19));
2179
2180         count = 0;
2181         if (in_syscall(pt))
2182                 count = min_t(int, args->n, cfm & 0x7f);
2183
2184         for (i = 0; i < count; i++) {
2185                 if (args->rw)
2186                         *ia64_rse_skip_regs(krbs, ndirty + i + args->i) =
2187                                 args->args[i];
2188                 else
2189                         args->args[i] = *ia64_rse_skip_regs(krbs,
2190                                 ndirty + i + args->i);
2191         }
2192
2193         if (!args->rw) {
2194                 while (i < args->n) {
2195                         args->args[i] = 0;
2196                         i++;
2197                 }
2198         }
2199 }
2200
2201 void ia64_syscall_get_set_arguments(struct task_struct *task,
2202         struct pt_regs *regs, unsigned int i, unsigned int n,
2203         unsigned long *args, int rw)
2204 {
2205         struct syscall_get_set_args data = {
2206                 .i = i,
2207                 .n = n,
2208                 .args = args,
2209                 .regs = regs,
2210                 .rw = rw,
2211         };
2212
2213         if (task == current)
2214                 unw_init_running(syscall_get_set_args_cb, &data);
2215         else {
2216                 struct unw_frame_info ufi;
2217                 memset(&ufi, 0, sizeof(ufi));
2218                 unw_init_from_blocked_task(&ufi, task);
2219                 syscall_get_set_args_cb(&ufi, &data);
2220         }
2221 }