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