arch/ia64/kernel/ptrace.c

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