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  * After PTRACE_ATTACH, a thread's register backing store area in user
 622  * space is assumed to contain correct data whenever the thread is
 623  * stopped.  arch_ptrace_stop takes care of this on tracing stops.
 624  * But if the child was already stopped for job control when we attach
 625  * to it, then it might not ever get into ptrace_stop by the time we
 626  * want to examine the user memory containing the RBS.
 627  */
 628 void
 629 ptrace_attach_sync_user_rbs (struct task_struct *child)
 630 {
 631         int stopped = 0;
 632         struct unw_frame_info info;
 633
 634         /*
 635          * If the child is in TASK_STOPPED, we need to change that to
 636          * TASK_TRACED momentarily while we operate on it.  This ensures
 637          * that the child won't be woken up and return to user mode while
 638          * we are doing the sync.  (It can only be woken up for SIGKILL.)
 639          */
 640
 641         read_lock(&tasklist_lock);
 642         if (child->sighand) {
 643                 spin_lock_irq(&child->sighand->siglock);
 644                 if (READ_ONCE(child->__state) == TASK_STOPPED &&
 645                     !test_and_set_tsk_thread_flag(child, TIF_RESTORE_RSE)) {
 646                         set_notify_resume(child);
 647
 648                         WRITE_ONCE(child->__state, TASK_TRACED);
 649                         stopped = 1;
 650                 }
 651                 spin_unlock_irq(&child->sighand->siglock);
 652         }
 653         read_unlock(&tasklist_lock);
 654
 655         if (!stopped)
 656                 return;
 657
 658         unw_init_from_blocked_task(&info, child);
 659         do_sync_rbs(&info, ia64_sync_user_rbs);
 660
 661         /*
 662          * Now move the child back into TASK_STOPPED if it should be in a
 663          * job control stop, so that SIGCONT can be used to wake it up.
 664          */
 665         read_lock(&tasklist_lock);
 666         if (child->sighand) {
 667                 spin_lock_irq(&child->sighand->siglock);
 668                 if (READ_ONCE(child->__state) == TASK_TRACED &&
 669                     (child->signal->flags & SIGNAL_STOP_STOPPED)) {
 670                         WRITE_ONCE(child->__state, TASK_STOPPED);
 671                 }
 672                 spin_unlock_irq(&child->sighand->siglock);
 673         }
 674         read_unlock(&tasklist_lock);
 675 }
 676
 677 /*
 678  * Write f32-f127 back to task->thread.fph if it has been modified.
 679  */
 680 inline void
 681 ia64_flush_fph (struct task_struct *task)
 682 {
 683         struct ia64_psr *psr = ia64_psr(task_pt_regs(task));
 684
 685         /*
 686          * Prevent migrating this task while
 687          * we're fiddling with the FPU state
 688          */
 689         preempt_disable();
 690         if (ia64_is_local_fpu_owner(task) && psr->mfh) {
 691                 psr->mfh = 0;
 692                 task->thread.flags |= IA64_THREAD_FPH_VALID;
 693                 ia64_save_fpu(&task->thread.fph[0]);
 694         }
 695         preempt_enable();
 696 }
 697
 698 /*
 699  * Sync the fph state of the task so that it can be manipulated
 700  * through thread.fph.  If necessary, f32-f127 are written back to
 701  * thread.fph or, if the fph state hasn't been used before, thread.fph
 702  * is cleared to zeroes.  Also, access to f32-f127 is disabled to
 703  * ensure that the task picks up the state from thread.fph when it
 704  * executes again.
 705  */
 706 void
 707 ia64_sync_fph (struct task_struct *task)
 708 {
 709         struct ia64_psr *psr = ia64_psr(task_pt_regs(task));
 710
 711         ia64_flush_fph(task);
 712         if (!(task->thread.flags & IA64_THREAD_FPH_VALID)) {
 713                 task->thread.flags |= IA64_THREAD_FPH_VALID;
 714                 memset(&task->thread.fph, 0, sizeof(task->thread.fph));
 715         }
 716         ia64_drop_fpu(task);
 717         psr->dfh = 1;
 718 }
 719
 720 /*
 721  * Change the machine-state of CHILD such that it will return via the normal
 722  * kernel exit-path, rather than the syscall-exit path.
 723  */
 724 static void
 725 convert_to_non_syscall (struct task_struct *child, struct pt_regs  *pt,
 726                         unsigned long cfm)
 727 {
 728         struct unw_frame_info info, prev_info;
 729         unsigned long ip, sp, pr;
 730
 731         unw_init_from_blocked_task(&info, child);
 732         while (1) {
 733                 prev_info = info;
 734                 if (unw_unwind(&info) < 0)
 735                         return;
 736
 737                 unw_get_sp(&info, &sp);
 738                 if ((long)((unsigned long)child + IA64_STK_OFFSET - sp)
 739                     < IA64_PT_REGS_SIZE) {
 740                         dprintk("ptrace.%s: ran off the top of the kernel "
 741                                 "stack\n", __func__);
 742                         return;
 743                 }
 744                 if (unw_get_pr (&prev_info, &pr) < 0) {
 745                         unw_get_rp(&prev_info, &ip);
 746                         dprintk("ptrace.%s: failed to read "
 747                                 "predicate register (ip=0x%lx)\n",
 748                                 __func__, ip);
 749                         return;
 750                 }
 751                 if (unw_is_intr_frame(&info)
 752                     && (pr & (1UL << PRED_USER_STACK)))
 753                         break;
 754         }
 755
 756         /*
 757          * Note: at the time of this call, the target task is blocked
 758          * in notify_resume_user() and by clearling PRED_LEAVE_SYSCALL
 759          * (aka, "pLvSys") we redirect execution from
 760          * .work_pending_syscall_end to .work_processed_kernel.
 761          */
 762         unw_get_pr(&prev_info, &pr);
 763         pr &= ~((1UL << PRED_SYSCALL) | (1UL << PRED_LEAVE_SYSCALL));
 764         pr |=  (1UL << PRED_NON_SYSCALL);
 765         unw_set_pr(&prev_info, pr);
 766
 767         pt->cr_ifs = (1UL << 63) | cfm;
 768         /*
 769          * Clear the memory that is NOT written on syscall-entry to
 770          * ensure we do not leak kernel-state to user when execution
 771          * resumes.
 772          */
 773         pt->r2 = 0;
 774         pt->r3 = 0;
 775         pt->r14 = 0;
 776         memset(&pt->r16, 0, 16*8);      /* clear r16-r31 */
 777         memset(&pt->f6, 0, 6*16);       /* clear f6-f11 */
 778         pt->b7 = 0;
 779         pt->ar_ccv = 0;
 780         pt->ar_csd = 0;
 781         pt->ar_ssd = 0;
 782 }
 783
 784 static int
 785 access_nat_bits (struct task_struct *child, struct pt_regs *pt,
 786                  struct unw_frame_info *info,
 787                  unsigned long *data, int write_access)
 788 {
 789         unsigned long regnum, nat_bits, scratch_unat, dummy = 0;
 790         char nat = 0;
 791
 792         if (write_access) {
 793                 nat_bits = *data;
 794                 scratch_unat = ia64_put_scratch_nat_bits(pt, nat_bits);
 795                 if (unw_set_ar(info, UNW_AR_UNAT, scratch_unat) < 0) {
 796                         dprintk("ptrace: failed to set ar.unat\n");
 797                         return -1;
 798                 }
 799                 for (regnum = 4; regnum <= 7; ++regnum) {
 800                         unw_get_gr(info, regnum, &dummy, &nat);
 801                         unw_set_gr(info, regnum, dummy,
 802                                    (nat_bits >> regnum) & 1);
 803                 }
 804         } else {
 805                 if (unw_get_ar(info, UNW_AR_UNAT, &scratch_unat) < 0) {
 806                         dprintk("ptrace: failed to read ar.unat\n");
 807                         return -1;
 808                 }
 809                 nat_bits = ia64_get_scratch_nat_bits(pt, scratch_unat);
 810                 for (regnum = 4; regnum <= 7; ++regnum) {
 811                         unw_get_gr(info, regnum, &dummy, &nat);
 812                         nat_bits |= (nat != 0) << regnum;
 813                 }
 814                 *data = nat_bits;
 815         }
 816         return 0;
 817 }
 818
 819 static int
 820 access_elf_reg(struct task_struct *target, struct unw_frame_info *info,
 821                 unsigned long addr, unsigned long *data, int write_access);
 822
 823 static long
 824 ptrace_getregs (struct task_struct *child, struct pt_all_user_regs __user *ppr)
 825 {
 826         unsigned long psr, ec, lc, rnat, bsp, cfm, nat_bits, val;
 827         struct unw_frame_info info;
 828         struct ia64_fpreg fpval;
 829         struct switch_stack *sw;
 830         struct pt_regs *pt;
 831         long ret, retval = 0;
 832         char nat = 0;
 833         int i;
 834
 835         if (!access_ok(ppr, sizeof(struct pt_all_user_regs)))
 836                 return -EIO;
 837
 838         pt = task_pt_regs(child);
 839         sw = (struct switch_stack *) (child->thread.ksp + 16);
 840         unw_init_from_blocked_task(&info, child);
 841         if (unw_unwind_to_user(&info) < 0) {
 842                 return -EIO;
 843         }
 844
 845         if (((unsigned long) ppr & 0x7) != 0) {
 846                 dprintk("ptrace:unaligned register address %p\n", ppr);
 847                 return -EIO;
 848         }
 849
 850         if (access_elf_reg(child, &info, ELF_CR_IPSR_OFFSET, &psr, 0) < 0 ||
 851             access_elf_reg(child, &info, ELF_AR_EC_OFFSET, &ec, 0) < 0 ||
 852             access_elf_reg(child, &info, ELF_AR_LC_OFFSET, &lc, 0) < 0 ||
 853             access_elf_reg(child, &info, ELF_AR_RNAT_OFFSET, &rnat, 0) < 0 ||
 854             access_elf_reg(child, &info, ELF_AR_BSP_OFFSET, &bsp, 0) < 0 ||
 855             access_elf_reg(child, &info, ELF_CFM_OFFSET, &cfm, 0) < 0 ||
 856             access_elf_reg(child, &info, ELF_NAT_OFFSET, &nat_bits, 0) < 0)
 857                 return -EIO;
 858
 859         /* control regs */
 860
 861         retval |= __put_user(pt->cr_iip, &ppr->cr_iip);
 862         retval |= __put_user(psr, &ppr->cr_ipsr);
 863
 864         /* app regs */
 865
 866         retval |= __put_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
 867         retval |= __put_user(pt->ar_rsc, &ppr->ar[PT_AUR_RSC]);
 868         retval |= __put_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
 869         retval |= __put_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
 870         retval |= __put_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
 871         retval |= __put_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);
 872
 873         retval |= __put_user(ec, &ppr->ar[PT_AUR_EC]);
 874         retval |= __put_user(lc, &ppr->ar[PT_AUR_LC]);
 875         retval |= __put_user(rnat, &ppr->ar[PT_AUR_RNAT]);
 876         retval |= __put_user(bsp, &ppr->ar[PT_AUR_BSP]);
 877         retval |= __put_user(cfm, &ppr->cfm);
 878
 879         /* gr1-gr3 */
 880
 881         retval |= __copy_to_user(&ppr->gr[1], &pt->r1, sizeof(long));
 882         retval |= __copy_to_user(&ppr->gr[2], &pt->r2, sizeof(long) *2);
 883
 884         /* gr4-gr7 */
 885
 886         for (i = 4; i < 8; i++) {
 887                 if (unw_access_gr(&info, i, &val, &nat, 0) < 0)
 888                         return -EIO;
 889                 retval |= __put_user(val, &ppr->gr[i]);
 890         }
 891
 892         /* gr8-gr11 */
 893
 894         retval |= __copy_to_user(&ppr->gr[8], &pt->r8, sizeof(long) * 4);
 895
 896         /* gr12-gr15 */
 897
 898         retval |= __copy_to_user(&ppr->gr[12], &pt->r12, sizeof(long) * 2);
 899         retval |= __copy_to_user(&ppr->gr[14], &pt->r14, sizeof(long));
 900         retval |= __copy_to_user(&ppr->gr[15], &pt->r15, sizeof(long));
 901
 902         /* gr16-gr31 */
 903
 904         retval |= __copy_to_user(&ppr->gr[16], &pt->r16, sizeof(long) * 16);
 905
 906         /* b0 */
 907
 908         retval |= __put_user(pt->b0, &ppr->br[0]);
 909
 910         /* b1-b5 */
 911
 912         for (i = 1; i < 6; i++) {
 913                 if (unw_access_br(&info, i, &val, 0) < 0)
 914                         return -EIO;
 915                 __put_user(val, &ppr->br[i]);
 916         }
 917
 918         /* b6-b7 */
 919
 920         retval |= __put_user(pt->b6, &ppr->br[6]);
 921         retval |= __put_user(pt->b7, &ppr->br[7]);
 922
 923         /* fr2-fr5 */
 924
 925         for (i = 2; i < 6; i++) {
 926                 if (unw_get_fr(&info, i, &fpval) < 0)
 927                         return -EIO;
 928                 retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
 929         }
 930
 931         /* fr6-fr11 */
 932
 933         retval |= __copy_to_user(&ppr->fr[6], &pt->f6,
 934                                  sizeof(struct ia64_fpreg) * 6);
 935
 936         /* fp scratch regs(12-15) */
 937
 938         retval |= __copy_to_user(&ppr->fr[12], &sw->f12,
 939                                  sizeof(struct ia64_fpreg) * 4);
 940
 941         /* fr16-fr31 */
 942
 943         for (i = 16; i < 32; i++) {
 944                 if (unw_get_fr(&info, i, &fpval) < 0)
 945                         return -EIO;
 946                 retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
 947         }
 948
 949         /* fph */
 950
 951         ia64_flush_fph(child);
 952         retval |= __copy_to_user(&ppr->fr[32], &child->thread.fph,
 953                                  sizeof(ppr->fr[32]) * 96);
 954
 955         /*  preds */
 956
 957         retval |= __put_user(pt->pr, &ppr->pr);
 958
 959         /* nat bits */
 960
 961         retval |= __put_user(nat_bits, &ppr->nat);
 962
 963         ret = retval ? -EIO : 0;
 964         return ret;
 965 }
 966
 967 static long
 968 ptrace_setregs (struct task_struct *child, struct pt_all_user_regs __user *ppr)
 969 {
 970         unsigned long psr, rsc, ec, lc, rnat, bsp, cfm, nat_bits, val = 0;
 971         struct unw_frame_info info;
 972         struct switch_stack *sw;
 973         struct ia64_fpreg fpval;
 974         struct pt_regs *pt;
 975         long retval = 0;
 976         int i;
 977
 978         memset(&fpval, 0, sizeof(fpval));
 979
 980         if (!access_ok(ppr, sizeof(struct pt_all_user_regs)))
 981                 return -EIO;
 982
 983         pt = task_pt_regs(child);
 984         sw = (struct switch_stack *) (child->thread.ksp + 16);
 985         unw_init_from_blocked_task(&info, child);
 986         if (unw_unwind_to_user(&info) < 0) {
 987                 return -EIO;
 988         }
 989
 990         if (((unsigned long) ppr & 0x7) != 0) {
 991                 dprintk("ptrace:unaligned register address %p\n", ppr);
 992                 return -EIO;
 993         }
 994
 995         /* control regs */
 996
 997         retval |= __get_user(pt->cr_iip, &ppr->cr_iip);
 998         retval |= __get_user(psr, &ppr->cr_ipsr);
 999
1000         /* app regs */
1001
1002         retval |= __get_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
1003         retval |= __get_user(rsc, &ppr->ar[PT_AUR_RSC]);
1004         retval |= __get_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
1005         retval |= __get_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
1006         retval |= __get_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
1007         retval |= __get_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);
1008
1009         retval |= __get_user(ec, &ppr->ar[PT_AUR_EC]);
1010         retval |= __get_user(lc, &ppr->ar[PT_AUR_LC]);
1011         retval |= __get_user(rnat, &ppr->ar[PT_AUR_RNAT]);
1012         retval |= __get_user(bsp, &ppr->ar[PT_AUR_BSP]);
1013         retval |= __get_user(cfm, &ppr->cfm);
1014
1015         /* gr1-gr3 */
1016
1017         retval |= __copy_from_user(&pt->r1, &ppr->gr[1], sizeof(long));
1018         retval |= __copy_from_user(&pt->r2, &ppr->gr[2], sizeof(long) * 2);
1019
1020         /* gr4-gr7 */
1021
1022         for (i = 4; i < 8; i++) {
1023                 retval |= __get_user(val, &ppr->gr[i]);
1024                 /* NaT bit will be set via PT_NAT_BITS: */
1025                 if (unw_set_gr(&info, i, val, 0) < 0)
1026                         return -EIO;
1027         }
1028
1029         /* gr8-gr11 */
1030
1031         retval |= __copy_from_user(&pt->r8, &ppr->gr[8], sizeof(long) * 4);
1032
1033         /* gr12-gr15 */
1034
1035         retval |= __copy_from_user(&pt->r12, &ppr->gr[12], sizeof(long) * 2);
1036         retval |= __copy_from_user(&pt->r14, &ppr->gr[14], sizeof(long));
1037         retval |= __copy_from_user(&pt->r15, &ppr->gr[15], sizeof(long));
1038
1039         /* gr16-gr31 */
1040
1041         retval |= __copy_from_user(&pt->r16, &ppr->gr[16], sizeof(long) * 16);
1042
1043         /* b0 */
1044
1045         retval |= __get_user(pt->b0, &ppr->br[0]);
1046
1047         /* b1-b5 */
1048
1049         for (i = 1; i < 6; i++) {
1050                 retval |= __get_user(val, &ppr->br[i]);
1051                 unw_set_br(&info, i, val);
1052         }
1053
1054         /* b6-b7 */
1055
1056         retval |= __get_user(pt->b6, &ppr->br[6]);
1057         retval |= __get_user(pt->b7, &ppr->br[7]);
1058
1059         /* fr2-fr5 */
1060
1061         for (i = 2; i < 6; i++) {
1062                 retval |= __copy_from_user(&fpval, &ppr->fr[i], sizeof(fpval));
1063                 if (unw_set_fr(&info, i, fpval) < 0)
1064                         return -EIO;
1065         }
1066
1067         /* fr6-fr11 */
1068
1069         retval |= __copy_from_user(&pt->f6, &ppr->fr[6],
1070                                    sizeof(ppr->fr[6]) * 6);
1071
1072         /* fp scratch regs(12-15) */
1073
1074         retval |= __copy_from_user(&sw->f12, &ppr->fr[12],
1075                                    sizeof(ppr->fr[12]) * 4);
1076
1077         /* fr16-fr31 */
1078
1079         for (i = 16; i < 32; i++) {
1080                 retval |= __copy_from_user(&fpval, &ppr->fr[i],
1081                                            sizeof(fpval));
1082                 if (unw_set_fr(&info, i, fpval) < 0)
1083                         return -EIO;
1084         }
1085
1086         /* fph */
1087
1088         ia64_sync_fph(child);
1089         retval |= __copy_from_user(&child->thread.fph, &ppr->fr[32],
1090                                    sizeof(ppr->fr[32]) * 96);
1091
1092         /* preds */
1093
1094         retval |= __get_user(pt->pr, &ppr->pr);
1095
1096         /* nat bits */
1097
1098         retval |= __get_user(nat_bits, &ppr->nat);
1099
1100         retval |= access_elf_reg(child, &info, ELF_CR_IPSR_OFFSET, &psr, 1);
1101         retval |= access_elf_reg(child, &info, ELF_AR_RSC_OFFSET, &rsc, 1);
1102         retval |= access_elf_reg(child, &info, ELF_AR_EC_OFFSET, &ec, 1);
1103         retval |= access_elf_reg(child, &info, ELF_AR_LC_OFFSET, &lc, 1);
1104         retval |= access_elf_reg(child, &info, ELF_AR_RNAT_OFFSET, &rnat, 1);
1105         retval |= access_elf_reg(child, &info, ELF_AR_BSP_OFFSET, &bsp, 1);
1106         retval |= access_elf_reg(child, &info, ELF_CFM_OFFSET, &cfm, 1);
1107         retval |= access_elf_reg(child, &info, ELF_NAT_OFFSET, &nat_bits, 1);
1108
1109         return retval ? -EIO : 0;
1110 }
1111
1112 void
1113 user_enable_single_step (struct task_struct *child)
1114 {
1115         struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
1116
1117         set_tsk_thread_flag(child, TIF_SINGLESTEP);
1118         child_psr->ss = 1;
1119 }
1120
1121 void
1122 user_enable_block_step (struct task_struct *child)
1123 {
1124         struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
1125
1126         set_tsk_thread_flag(child, TIF_SINGLESTEP);
1127         child_psr->tb = 1;
1128 }
1129
1130 void
1131 user_disable_single_step (struct task_struct *child)
1132 {
1133         struct ia64_psr *child_psr = ia64_psr(task_pt_regs(child));
1134
1135         /* make sure the single step/taken-branch trap bits are not set: */
1136         clear_tsk_thread_flag(child, TIF_SINGLESTEP);
1137         child_psr->ss = 0;
1138         child_psr->tb = 0;
1139 }
1140
1141 /*
1142  * Called by kernel/ptrace.c when detaching..
1143  *
1144  * Make sure the single step bit is not set.
1145  */
1146 void
1147 ptrace_disable (struct task_struct *child)
1148 {
1149         user_disable_single_step(child);
1150 }
1151
1152 static int
1153 access_uarea (struct task_struct *child, unsigned long addr,
1154               unsigned long *data, int write_access);
1155
1156 long
1157 arch_ptrace (struct task_struct *child, long request,
1158              unsigned long addr, unsigned long data)
1159 {
1160         switch (request) {
1161         case PTRACE_PEEKTEXT:
1162         case PTRACE_PEEKDATA:
1163                 /* read word at location addr */
1164                 if (ptrace_access_vm(child, addr, &data, sizeof(data),
1165                                 FOLL_FORCE)
1166                     != sizeof(data))
1167                         return -EIO;
1168                 /* ensure return value is not mistaken for error code */
1169                 force_successful_syscall_return();
1170                 return data;
1171
1172         /* PTRACE_POKETEXT and PTRACE_POKEDATA is handled
1173          * by the generic ptrace_request().
1174          */
1175
1176         case PTRACE_PEEKUSR:
1177                 /* read the word at addr in the USER area */
1178                 if (access_uarea(child, addr, &data, 0) < 0)
1179                         return -EIO;
1180                 /* ensure return value is not mistaken for error code */
1181                 force_successful_syscall_return();
1182                 return data;
1183
1184         case PTRACE_POKEUSR:
1185                 /* write the word at addr in the USER area */
1186                 if (access_uarea(child, addr, &data, 1) < 0)
1187                         return -EIO;
1188                 return 0;
1189
1190         case PTRACE_OLD_GETSIGINFO:
1191                 /* for backwards-compatibility */
1192                 return ptrace_request(child, PTRACE_GETSIGINFO, addr, data);
1193
1194         case PTRACE_OLD_SETSIGINFO:
1195                 /* for backwards-compatibility */
1196                 return ptrace_request(child, PTRACE_SETSIGINFO, addr, data);
1197
1198         case PTRACE_GETREGS:
1199                 return ptrace_getregs(child,
1200                                       (struct pt_all_user_regs __user *) data);
1201
1202         case PTRACE_SETREGS:
1203                 return ptrace_setregs(child,
1204                                       (struct pt_all_user_regs __user *) data);
1205
1206         default:
1207                 return ptrace_request(child, request, addr, data);
1208         }
1209 }
1210
1211
1212 /* "asmlinkage" so the input arguments are preserved... */
1213
1214 asmlinkage long
1215 syscall_trace_enter (long arg0, long arg1, long arg2, long arg3,
1216                      long arg4, long arg5, long arg6, long arg7,
1217                      struct pt_regs regs)
1218 {
1219         if (test_thread_flag(TIF_SYSCALL_TRACE))
1220                 if (ptrace_report_syscall_entry(&regs))
1221                         return -ENOSYS;
1222
1223         /* copy user rbs to kernel rbs */
1224         if (test_thread_flag(TIF_RESTORE_RSE))
1225                 ia64_sync_krbs();
1226
1227
1228         audit_syscall_entry(regs.r15, arg0, arg1, arg2, arg3);
1229
1230         return 0;
1231 }
1232
1233 /* "asmlinkage" so the input arguments are preserved... */
1234
1235 asmlinkage void
1236 syscall_trace_leave (long arg0, long arg1, long arg2, long arg3,
1237                      long arg4, long arg5, long arg6, long arg7,
1238                      struct pt_regs regs)
1239 {
1240         int step;
1241
1242         audit_syscall_exit(&regs);
1243
1244         step = test_thread_flag(TIF_SINGLESTEP);
1245         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1246                 ptrace_report_syscall_exit(&regs, step);
1247
1248         /* copy user rbs to kernel rbs */
1249         if (test_thread_flag(TIF_RESTORE_RSE))
1250                 ia64_sync_krbs();
1251 }
1252
1253 /* Utrace implementation starts here */
1254 struct regset_get {
1255         void *kbuf;
1256         void __user *ubuf;
1257 };
1258
1259 struct regset_set {
1260         const void *kbuf;
1261         const void __user *ubuf;
1262 };
1263
1264 struct regset_getset {
1265         struct task_struct *target;
1266         const struct user_regset *regset;
1267         union {
1268                 struct regset_get get;
1269                 struct regset_set set;
1270         } u;
1271         unsigned int pos;
1272         unsigned int count;
1273         int ret;
1274 };
1275
1276 static const ptrdiff_t pt_offsets[32] =
1277 {
1278 #define R(n) offsetof(struct pt_regs, r##n)
1279         [0] = -1, R(1), R(2), R(3),
1280         [4] = -1, [5] = -1, [6] = -1, [7] = -1,
1281         R(8), R(9), R(10), R(11), R(12), R(13), R(14), R(15),
1282         R(16), R(17), R(18), R(19), R(20), R(21), R(22), R(23),
1283         R(24), R(25), R(26), R(27), R(28), R(29), R(30), R(31),
1284 #undef R
1285 };
1286
1287 static int
1288 access_elf_gpreg(struct task_struct *target, struct unw_frame_info *info,
1289                 unsigned long addr, unsigned long *data, int write_access)
1290 {
1291         struct pt_regs *pt = task_pt_regs(target);
1292         unsigned reg = addr / sizeof(unsigned long);
1293         ptrdiff_t d = pt_offsets[reg];
1294
1295         if (d >= 0) {
1296                 unsigned long *ptr = (void *)pt + d;
1297                 if (write_access)
1298                         *ptr = *data;
1299                 else
1300                         *data = *ptr;
1301                 return 0;
1302         } else {
1303                 char nat = 0;
1304                 if (write_access) {
1305                         /* read NaT bit first: */
1306                         unsigned long dummy;
1307                         int ret = unw_get_gr(info, reg, &dummy, &nat);
1308                         if (ret < 0)
1309                                 return ret;
1310                 }
1311                 return unw_access_gr(info, reg, data, &nat, write_access);
1312         }
1313 }
1314
1315 static int
1316 access_elf_breg(struct task_struct *target, struct unw_frame_info *info,
1317                 unsigned long addr, unsigned long *data, int write_access)
1318 {
1319         struct pt_regs *pt;
1320         unsigned long *ptr = NULL;
1321
1322         pt = task_pt_regs(target);
1323         switch (addr) {
1324         case ELF_BR_OFFSET(0):
1325                 ptr = &pt->b0;
1326                 break;
1327         case ELF_BR_OFFSET(1) ... ELF_BR_OFFSET(5):
1328                 return unw_access_br(info, (addr - ELF_BR_OFFSET(0))/8,
1329                                      data, write_access);
1330         case ELF_BR_OFFSET(6):
1331                 ptr = &pt->b6;
1332                 break;
1333         case ELF_BR_OFFSET(7):
1334                 ptr = &pt->b7;
1335         }
1336         if (write_access)
1337                 *ptr = *data;
1338         else
1339                 *data = *ptr;
1340         return 0;
1341 }
1342
1343 static int
1344 access_elf_areg(struct task_struct *target, struct unw_frame_info *info,
1345                 unsigned long addr, unsigned long *data, int write_access)
1346 {
1347         struct pt_regs *pt;
1348         unsigned long cfm, urbs_end;
1349         unsigned long *ptr = NULL;
1350
1351         pt = task_pt_regs(target);
1352         if (addr >= ELF_AR_RSC_OFFSET && addr <= ELF_AR_SSD_OFFSET) {
1353                 switch (addr) {
1354                 case ELF_AR_RSC_OFFSET:
1355                         /* force PL3 */
1356                         if (write_access)
1357                                 pt->ar_rsc = *data | (3 << 2);
1358                         else
1359                                 *data = pt->ar_rsc;
1360                         return 0;
1361                 case ELF_AR_BSP_OFFSET:
1362                         /*
1363                          * By convention, we use PT_AR_BSP to refer to
1364                          * the end of the user-level backing store.
1365                          * Use ia64_rse_skip_regs(PT_AR_BSP, -CFM.sof)
1366                          * to get the real value of ar.bsp at the time
1367                          * the kernel was entered.
1368                          *
1369                          * Furthermore, when changing the contents of
1370                          * PT_AR_BSP (or PT_CFM) while the task is
1371                          * blocked in a system call, convert the state
1372                          * so that the non-system-call exit
1373                          * path is used.  This ensures that the proper
1374                          * state will be picked up when resuming
1375                          * execution.  However, it *also* means that
1376                          * once we write PT_AR_BSP/PT_CFM, it won't be
1377                          * possible to modify the syscall arguments of
1378                          * the pending system call any longer.  This
1379                          * shouldn't be an issue because modifying
1380                          * PT_AR_BSP/PT_CFM generally implies that
1381                          * we're either abandoning the pending system
1382                          * call or that we defer it's re-execution
1383                          * (e.g., due to GDB doing an inferior
1384                          * function call).
1385                          */
1386                         urbs_end = ia64_get_user_rbs_end(target, pt, &cfm);
1387                         if (write_access) {
1388                                 if (*data != urbs_end) {
1389                                         if (in_syscall(pt))
1390                                                 convert_to_non_syscall(target,
1391                                                                        pt,
1392                                                                        cfm);
1393                                         /*
1394                                          * Simulate user-level write
1395                                          * of ar.bsp:
1396                                          */
1397                                         pt->loadrs = 0;
1398                                         pt->ar_bspstore = *data;
1399                                 }
1400                         } else
1401                                 *data = urbs_end;
1402                         return 0;
1403                 case ELF_AR_BSPSTORE_OFFSET:
1404                         ptr = &pt->ar_bspstore;
1405                         break;
1406                 case ELF_AR_RNAT_OFFSET:
1407                         ptr = &pt->ar_rnat;
1408                         break;
1409                 case ELF_AR_CCV_OFFSET:
1410                         ptr = &pt->ar_ccv;
1411                         break;
1412                 case ELF_AR_UNAT_OFFSET:
1413                         ptr = &pt->ar_unat;
1414                         break;
1415                 case ELF_AR_FPSR_OFFSET:
1416                         ptr = &pt->ar_fpsr;
1417                         break;
1418                 case ELF_AR_PFS_OFFSET:
1419                         ptr = &pt->ar_pfs;
1420                         break;
1421                 case ELF_AR_LC_OFFSET:
1422                         return unw_access_ar(info, UNW_AR_LC, data,
1423                                              write_access);
1424                 case ELF_AR_EC_OFFSET:
1425                         return unw_access_ar(info, UNW_AR_EC, data,
1426                                              write_access);
1427                 case ELF_AR_CSD_OFFSET:
1428                         ptr = &pt->ar_csd;
1429                         break;
1430                 case ELF_AR_SSD_OFFSET:
1431                         ptr = &pt->ar_ssd;
1432                 }
1433         } else if (addr >= ELF_CR_IIP_OFFSET && addr <= ELF_CR_IPSR_OFFSET) {
1434                 switch (addr) {
1435                 case ELF_CR_IIP_OFFSET:
1436                         ptr = &pt->cr_iip;
1437                         break;
1438                 case ELF_CFM_OFFSET:
1439                         urbs_end = ia64_get_user_rbs_end(target, pt, &cfm);
1440                         if (write_access) {
1441                                 if (((cfm ^ *data) & PFM_MASK) != 0) {
1442                                         if (in_syscall(pt))
1443                                                 convert_to_non_syscall(target,
1444                                                                        pt,
1445                                                                        cfm);
1446                                         pt->cr_ifs = ((pt->cr_ifs & ~PFM_MASK)
1447                                                       | (*data & PFM_MASK));
1448                                 }
1449                         } else
1450                                 *data = cfm;
1451                         return 0;
1452                 case ELF_CR_IPSR_OFFSET:
1453                         if (write_access) {
1454                                 unsigned long tmp = *data;
1455                                 /* psr.ri==3 is a reserved value: SDM 2:25 */
1456                                 if ((tmp & IA64_PSR_RI) == IA64_PSR_RI)
1457                                         tmp &= ~IA64_PSR_RI;
1458                                 pt->cr_ipsr = ((tmp & IPSR_MASK)
1459                                                | (pt->cr_ipsr & ~IPSR_MASK));
1460                         } else
1461                                 *data = (pt->cr_ipsr & IPSR_MASK);
1462                         return 0;
1463                 }
1464         } else if (addr == ELF_NAT_OFFSET)
1465                 return access_nat_bits(target, pt, info,
1466                                        data, write_access);
1467         else if (addr == ELF_PR_OFFSET)
1468                 ptr = &pt->pr;
1469         else
1470                 return -1;
1471
1472         if (write_access)
1473                 *ptr = *data;
1474         else
1475                 *data = *ptr;
1476
1477         return 0;
1478 }
1479
1480 static int
1481 access_elf_reg(struct task_struct *target, struct unw_frame_info *info,
1482                 unsigned long addr, unsigned long *data, int write_access)
1483 {
1484         if (addr >= ELF_GR_OFFSET(1) && addr <= ELF_GR_OFFSET(31))
1485                 return access_elf_gpreg(target, info, addr, data, write_access);
1486         else if (addr >= ELF_BR_OFFSET(0) && addr <= ELF_BR_OFFSET(7))
1487                 return access_elf_breg(target, info, addr, data, write_access);
1488         else
1489                 return access_elf_areg(target, info, addr, data, write_access);
1490 }
1491
1492 struct regset_membuf {
1493         struct membuf to;
1494         int ret;
1495 };
1496
1497 static void do_gpregs_get(struct unw_frame_info *info, void *arg)
1498 {
1499         struct regset_membuf *dst = arg;
1500         struct membuf to = dst->to;
1501         unsigned int n;
1502         elf_greg_t reg;
1503
1504         if (unw_unwind_to_user(info) < 0)
1505                 return;
1506
1507         /*
1508          * coredump format:
1509          *      r0-r31
1510          *      NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
1511          *      predicate registers (p0-p63)
1512          *      b0-b7
1513          *      ip cfm user-mask
1514          *      ar.rsc ar.bsp ar.bspstore ar.rnat
1515          *      ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
1516          */
1517
1518
1519         /* Skip r0 */
1520         membuf_zero(&to, 8);
1521         for (n = 8; to.left && n < ELF_AR_END_OFFSET; n += 8) {
1522                 if (access_elf_reg(info->task, info, n, &reg, 0) < 0) {
1523                         dst->ret = -EIO;
1524                         return;
1525                 }
1526                 membuf_store(&to, reg);
1527         }
1528 }
1529
1530 static void do_gpregs_set(struct unw_frame_info *info, void *arg)
1531 {
1532         struct regset_getset *dst = arg;
1533
1534         if (unw_unwind_to_user(info) < 0)
1535                 return;
1536
1537         if (!dst->count)
1538                 return;
1539         /* Skip r0 */
1540         if (dst->pos < ELF_GR_OFFSET(1)) {
1541                 dst->ret = user_regset_copyin_ignore(&dst->pos, &dst->count,
1542                                                        &dst->u.set.kbuf,
1543                                                        &dst->u.set.ubuf,
1544                                                        0, ELF_GR_OFFSET(1));
1545                 if (dst->ret)
1546                         return;
1547         }
1548
1549         while (dst->count && dst->pos < ELF_AR_END_OFFSET) {
1550                 unsigned int n, from, to;
1551                 elf_greg_t tmp[16];
1552
1553                 from = dst->pos;
1554                 to = from + sizeof(tmp);
1555                 if (to > ELF_AR_END_OFFSET)
1556                         to = ELF_AR_END_OFFSET;
1557                 /* get up to 16 values */
1558                 dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1559                                 &dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
1560                                 from, to);
1561                 if (dst->ret)
1562                         return;
1563                 /* now copy them into registers */
1564                 for (n = 0; from < dst->pos; from += sizeof(elf_greg_t), n++)
1565                         if (access_elf_reg(dst->target, info, from,
1566                                                 &tmp[n], 1) < 0) {
1567                                 dst->ret = -EIO;
1568                                 return;
1569                         }
1570         }
1571 }
1572
1573 #define ELF_FP_OFFSET(i)        (i * sizeof(elf_fpreg_t))
1574
1575 static void do_fpregs_get(struct unw_frame_info *info, void *arg)
1576 {
1577         struct task_struct *task = info->task;
1578         struct regset_membuf *dst = arg;
1579         struct membuf to = dst->to;
1580         elf_fpreg_t reg;
1581         unsigned int n;
1582
1583         if (unw_unwind_to_user(info) < 0)
1584                 return;
1585
1586         /* Skip pos 0 and 1 */
1587         membuf_zero(&to, 2 * sizeof(elf_fpreg_t));
1588
1589         /* fr2-fr31 */
1590         for (n = 2; to.left && n < 32; n++) {
1591                 if (unw_get_fr(info, n, &reg)) {
1592                         dst->ret = -EIO;
1593                         return;
1594                 }
1595                 membuf_write(&to, &reg, sizeof(reg));
1596         }
1597
1598         /* fph */
1599         if (!to.left)
1600                 return;
1601
1602         ia64_flush_fph(task);
1603         if (task->thread.flags & IA64_THREAD_FPH_VALID)
1604                 membuf_write(&to, &task->thread.fph, 96 * sizeof(reg));
1605         else
1606                 membuf_zero(&to, 96 * sizeof(reg));
1607 }
1608
1609 static void do_fpregs_set(struct unw_frame_info *info, void *arg)
1610 {
1611         struct regset_getset *dst = arg;
1612         elf_fpreg_t fpreg, tmp[30];
1613         int index, start, end;
1614
1615         if (unw_unwind_to_user(info) < 0)
1616                 return;
1617
1618         /* Skip pos 0 and 1 */
1619         if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(2)) {
1620                 dst->ret = user_regset_copyin_ignore(&dst->pos, &dst->count,
1621                                                        &dst->u.set.kbuf,
1622                                                        &dst->u.set.ubuf,
1623                                                        0, ELF_FP_OFFSET(2));
1624                 if (dst->count == 0 || dst->ret)
1625                         return;
1626         }
1627
1628         /* fr2-fr31 */
1629         if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(32)) {
1630                 start = dst->pos;
1631                 end = min(((unsigned int)ELF_FP_OFFSET(32)),
1632                          dst->pos + dst->count);
1633                 dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1634                                 &dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
1635                                 ELF_FP_OFFSET(2), ELF_FP_OFFSET(32));
1636                 if (dst->ret)
1637                         return;
1638
1639                 if (start & 0xF) { /* only write high part */
1640                         if (unw_get_fr(info, start / sizeof(elf_fpreg_t),
1641                                          &fpreg)) {
1642                                 dst->ret = -EIO;
1643                                 return;
1644                         }
1645                         tmp[start / sizeof(elf_fpreg_t) - 2].u.bits[0]
1646                                 = fpreg.u.bits[0];
1647                         start &= ~0xFUL;
1648                 }
1649                 if (end & 0xF) { /* only write low part */
1650                         if (unw_get_fr(info, end / sizeof(elf_fpreg_t),
1651                                         &fpreg)) {
1652                                 dst->ret = -EIO;
1653                                 return;
1654                         }
1655                         tmp[end / sizeof(elf_fpreg_t) - 2].u.bits[1]
1656                                 = fpreg.u.bits[1];
1657                         end = (end + 0xF) & ~0xFUL;
1658                 }
1659
1660                 for ( ; start < end ; start += sizeof(elf_fpreg_t)) {
1661                         index = start / sizeof(elf_fpreg_t);
1662                         if (unw_set_fr(info, index, tmp[index - 2])) {
1663                                 dst->ret = -EIO;
1664                                 return;
1665                         }
1666                 }
1667                 if (dst->ret || dst->count == 0)
1668                         return;
1669         }
1670
1671         /* fph */
1672         if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(128)) {
1673                 ia64_sync_fph(dst->target);
1674                 dst->ret = user_regset_copyin(&dst->pos, &dst->count,
1675                                                 &dst->u.set.kbuf,
1676                                                 &dst->u.set.ubuf,
1677                                                 &dst->target->thread.fph,
1678                                                 ELF_FP_OFFSET(32), -1);
1679         }
1680 }
1681
1682 static void
1683 unwind_and_call(void (*call)(struct unw_frame_info *, void *),
1684                struct task_struct *target, void *data)
1685 {
1686         if (target == current)
1687                 unw_init_running(call, data);
1688         else {
1689                 struct unw_frame_info info;
1690                 memset(&info, 0, sizeof(info));
1691                 unw_init_from_blocked_task(&info, target);
1692                 (*call)(&info, data);
1693         }
1694 }
1695
1696 static int
1697 do_regset_call(void (*call)(struct unw_frame_info *, void *),
1698                struct task_struct *target,
1699                const struct user_regset *regset,
1700                unsigned int pos, unsigned int count,
1701                const void *kbuf, const void __user *ubuf)
1702 {
1703         struct regset_getset info = { .target = target, .regset = regset,
1704                                  .pos = pos, .count = count,
1705                                  .u.set = { .kbuf = kbuf, .ubuf = ubuf },
1706                                  .ret = 0 };
1707         unwind_and_call(call, target, &info);
1708         return info.ret;
1709 }
1710
1711 static int
1712 gpregs_get(struct task_struct *target,
1713            const struct user_regset *regset,
1714            struct membuf to)
1715 {
1716         struct regset_membuf info = {.to = to};
1717         unwind_and_call(do_gpregs_get, target, &info);
1718         return info.ret;
1719 }
1720
1721 static int gpregs_set(struct task_struct *target,
1722                 const struct user_regset *regset,
1723                 unsigned int pos, unsigned int count,
1724                 const void *kbuf, const void __user *ubuf)
1725 {
1726         return do_regset_call(do_gpregs_set, target, regset, pos, count,
1727                 kbuf, ubuf);
1728 }
1729
1730 static void do_gpregs_writeback(struct unw_frame_info *info, void *arg)
1731 {
1732         do_sync_rbs(info, ia64_sync_user_rbs);
1733 }
1734
1735 /*
1736  * This is called to write back the register backing store.
1737  * ptrace does this before it stops, so that a tracer reading the user
1738  * memory after the thread stops will get the current register data.
1739  */
1740 static int
1741 gpregs_writeback(struct task_struct *target,
1742                  const struct user_regset *regset,
1743                  int now)
1744 {
1745         if (test_and_set_tsk_thread_flag(target, TIF_RESTORE_RSE))
1746                 return 0;
1747         set_notify_resume(target);
1748         return do_regset_call(do_gpregs_writeback, target, regset, 0, 0,
1749                 NULL, NULL);
1750 }
1751
1752 static int
1753 fpregs_active(struct task_struct *target, const struct user_regset *regset)
1754 {
1755         return (target->thread.flags & IA64_THREAD_FPH_VALID) ? 128 : 32;
1756 }
1757
1758 static int fpregs_get(struct task_struct *target,
1759                 const struct user_regset *regset,
1760                 struct membuf to)
1761 {
1762         struct regset_membuf info = {.to = to};
1763         unwind_and_call(do_fpregs_get, target, &info);
1764         return info.ret;
1765 }
1766
1767 static int fpregs_set(struct task_struct *target,
1768                 const struct user_regset *regset,
1769                 unsigned int pos, unsigned int count,
1770                 const void *kbuf, const void __user *ubuf)
1771 {
1772         return do_regset_call(do_fpregs_set, target, regset, pos, count,
1773                 kbuf, ubuf);
1774 }
1775
1776 static int
1777 access_uarea(struct task_struct *child, unsigned long addr,
1778               unsigned long *data, int write_access)
1779 {
1780         unsigned int pos = -1; /* an invalid value */
1781         unsigned long *ptr, regnum;
1782
1783         if ((addr & 0x7) != 0) {
1784                 dprintk("ptrace: unaligned register address 0x%lx\n", addr);
1785                 return -1;
1786         }
1787         if ((addr >= PT_NAT_BITS + 8 && addr < PT_F2) ||
1788                 (addr >= PT_R7 + 8 && addr < PT_B1) ||
1789                 (addr >= PT_AR_LC + 8 && addr < PT_CR_IPSR) ||
1790                 (addr >= PT_AR_SSD + 8 && addr < PT_DBR)) {
1791                 dprintk("ptrace: rejecting access to register "
1792                                         "address 0x%lx\n", addr);
1793                 return -1;
1794         }
1795
1796         switch (addr) {
1797         case PT_F32 ... (PT_F127 + 15):
1798                 pos = addr - PT_F32 + ELF_FP_OFFSET(32);
1799                 break;
1800         case PT_F2 ... (PT_F5 + 15):
1801                 pos = addr - PT_F2 + ELF_FP_OFFSET(2);
1802                 break;
1803         case PT_F10 ... (PT_F31 + 15):
1804                 pos = addr - PT_F10 + ELF_FP_OFFSET(10);
1805                 break;
1806         case PT_F6 ... (PT_F9 + 15):
1807                 pos = addr - PT_F6 + ELF_FP_OFFSET(6);
1808                 break;
1809         }
1810
1811         if (pos != -1) {
1812                 unsigned reg = pos / sizeof(elf_fpreg_t);
1813                 int which_half = (pos / sizeof(unsigned long)) & 1;
1814
1815                 if (reg < 32) { /* fr2-fr31 */
1816                         struct unw_frame_info info;
1817                         elf_fpreg_t fpreg;
1818
1819                         memset(&info, 0, sizeof(info));
1820                         unw_init_from_blocked_task(&info, child);
1821                         if (unw_unwind_to_user(&info) < 0)
1822                                 return 0;
1823
1824                         if (unw_get_fr(&info, reg, &fpreg))
1825                                 return -1;
1826                         if (write_access) {
1827                                 fpreg.u.bits[which_half] = *data;
1828                                 if (unw_set_fr(&info, reg, fpreg))
1829                                         return -1;
1830                         } else {
1831                                 *data = fpreg.u.bits[which_half];
1832                         }
1833                 } else { /* fph */
1834                         elf_fpreg_t *p = &child->thread.fph[reg - 32];
1835                         unsigned long *bits = &p->u.bits[which_half];
1836
1837                         ia64_sync_fph(child);
1838                         if (write_access)
1839                                 *bits = *data;
1840                         else if (child->thread.flags & IA64_THREAD_FPH_VALID)
1841                                 *data = *bits;
1842                         else
1843                                 *data = 0;
1844                 }
1845                 return 0;
1846         }
1847
1848         switch (addr) {
1849         case PT_NAT_BITS:
1850                 pos = ELF_NAT_OFFSET;
1851                 break;
1852         case PT_R4 ... PT_R7:
1853                 pos = addr - PT_R4 + ELF_GR_OFFSET(4);
1854                 break;
1855         case PT_B1 ... PT_B5:
1856                 pos = addr - PT_B1 + ELF_BR_OFFSET(1);
1857                 break;
1858         case PT_AR_EC:
1859                 pos = ELF_AR_EC_OFFSET;
1860                 break;
1861         case PT_AR_LC:
1862                 pos = ELF_AR_LC_OFFSET;
1863                 break;
1864         case PT_CR_IPSR:
1865                 pos = ELF_CR_IPSR_OFFSET;
1866                 break;
1867         case PT_CR_IIP:
1868                 pos = ELF_CR_IIP_OFFSET;
1869                 break;
1870         case PT_CFM:
1871                 pos = ELF_CFM_OFFSET;
1872                 break;
1873         case PT_AR_UNAT:
1874                 pos = ELF_AR_UNAT_OFFSET;
1875                 break;
1876         case PT_AR_PFS:
1877                 pos = ELF_AR_PFS_OFFSET;
1878                 break;
1879         case PT_AR_RSC:
1880                 pos = ELF_AR_RSC_OFFSET;
1881                 break;
1882         case PT_AR_RNAT:
1883                 pos = ELF_AR_RNAT_OFFSET;
1884                 break;
1885         case PT_AR_BSPSTORE:
1886                 pos = ELF_AR_BSPSTORE_OFFSET;
1887                 break;
1888         case PT_PR:
1889                 pos = ELF_PR_OFFSET;
1890                 break;
1891         case PT_B6:
1892                 pos = ELF_BR_OFFSET(6);
1893                 break;
1894         case PT_AR_BSP:
1895                 pos = ELF_AR_BSP_OFFSET;
1896                 break;
1897         case PT_R1 ... PT_R3:
1898                 pos = addr - PT_R1 + ELF_GR_OFFSET(1);
1899                 break;
1900         case PT_R12 ... PT_R15:
1901                 pos = addr - PT_R12 + ELF_GR_OFFSET(12);
1902                 break;
1903         case PT_R8 ... PT_R11:
1904                 pos = addr - PT_R8 + ELF_GR_OFFSET(8);
1905                 break;
1906         case PT_R16 ... PT_R31:
1907                 pos = addr - PT_R16 + ELF_GR_OFFSET(16);
1908                 break;
1909         case PT_AR_CCV:
1910                 pos = ELF_AR_CCV_OFFSET;
1911                 break;
1912         case PT_AR_FPSR:
1913                 pos = ELF_AR_FPSR_OFFSET;
1914                 break;
1915         case PT_B0:
1916                 pos = ELF_BR_OFFSET(0);
1917                 break;
1918         case PT_B7:
1919                 pos = ELF_BR_OFFSET(7);
1920                 break;
1921         case PT_AR_CSD:
1922                 pos = ELF_AR_CSD_OFFSET;
1923                 break;
1924         case PT_AR_SSD:
1925                 pos = ELF_AR_SSD_OFFSET;
1926                 break;
1927         }
1928
1929         if (pos != -1) {
1930                 struct unw_frame_info info;
1931
1932                 memset(&info, 0, sizeof(info));
1933                 unw_init_from_blocked_task(&info, child);
1934                 if (unw_unwind_to_user(&info) < 0)
1935                         return 0;
1936
1937                 return access_elf_reg(child, &info, pos, data, write_access);
1938         }
1939
1940         /* access debug registers */
1941         if (addr >= PT_IBR) {
1942                 regnum = (addr - PT_IBR) >> 3;
1943                 ptr = &child->thread.ibr[0];
1944         } else {
1945                 regnum = (addr - PT_DBR) >> 3;
1946                 ptr = &child->thread.dbr[0];
1947         }
1948
1949         if (regnum >= 8) {
1950                 dprintk("ptrace: rejecting access to register "
1951                                 "address 0x%lx\n", addr);
1952                 return -1;
1953         }
1954
1955         if (!(child->thread.flags & IA64_THREAD_DBG_VALID)) {
1956                 child->thread.flags |= IA64_THREAD_DBG_VALID;
1957                 memset(child->thread.dbr, 0,
1958                                 sizeof(child->thread.dbr));
1959                 memset(child->thread.ibr, 0,
1960                                 sizeof(child->thread.ibr));
1961         }
1962
1963         ptr += regnum;
1964
1965         if ((regnum & 1) && write_access) {
1966                 /* don't let the user set kernel-level breakpoints: */
1967                 *ptr = *data & ~(7UL << 56);
1968                 return 0;
1969         }
1970         if (write_access)
1971                 *ptr = *data;
1972         else
1973                 *data = *ptr;
1974         return 0;
1975 }
1976
1977 static const struct user_regset native_regsets[] = {
1978         {
1979                 .core_note_type = NT_PRSTATUS,
1980                 .n = ELF_NGREG,
1981                 .size = sizeof(elf_greg_t), .align = sizeof(elf_greg_t),
1982                 .regset_get = gpregs_get, .set = gpregs_set,
1983                 .writeback = gpregs_writeback
1984         },
1985         {
1986                 .core_note_type = NT_PRFPREG,
1987                 .n = ELF_NFPREG,
1988                 .size = sizeof(elf_fpreg_t), .align = sizeof(elf_fpreg_t),
1989                 .regset_get = fpregs_get, .set = fpregs_set, .active = fpregs_active
1990         },
1991 };
1992
1993 static const struct user_regset_view user_ia64_view = {
1994         .name = "ia64",
1995         .e_machine = EM_IA_64,
1996         .regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
1997 };
1998
1999 const struct user_regset_view *task_user_regset_view(struct task_struct *tsk)
2000 {
2001         return &user_ia64_view;
2002 }
2003
2004 struct syscall_get_args {
2005         unsigned int i;
2006         unsigned int n;
2007         unsigned long *args;
2008         struct pt_regs *regs;
2009 };
2010
2011 static void syscall_get_args_cb(struct unw_frame_info *info, void *data)
2012 {
2013         struct syscall_get_args *args = data;
2014         struct pt_regs *pt = args->regs;
2015         unsigned long *krbs, cfm, ndirty, nlocals, nouts;
2016         int i, count;
2017
2018         if (unw_unwind_to_user(info) < 0)
2019                 return;
2020
2021         /*
2022          * We get here via a few paths:
2023          * - break instruction: cfm is shared with caller.
2024          *   syscall args are in out= regs, locals are non-empty.
2025          * - epsinstruction: cfm is set by br.call
2026          *   locals don't exist.
2027          *
2028          * For both cases argguments are reachable in cfm.sof - cfm.sol.
2029          * CFM: [ ... | sor: 17..14 | sol : 13..7 | sof : 6..0 ]
2030          */
2031         cfm = pt->cr_ifs;
2032         nlocals = (cfm >> 7) & 0x7f; /* aka sol */
2033         nouts = (cfm & 0x7f) - nlocals; /* aka sof - sol */
2034         krbs = (unsigned long *)info->task + IA64_RBS_OFFSET/8;
2035         ndirty = ia64_rse_num_regs(krbs, krbs + (pt->loadrs >> 19));
2036
2037         count = 0;
2038         if (in_syscall(pt))
2039                 count = min_t(int, args->n, nouts);
2040
2041         /* Iterate over outs. */
2042         for (i = 0; i < count; i++) {
2043                 int j = ndirty + nlocals + i + args->i;
2044                 args->args[i] = *ia64_rse_skip_regs(krbs, j);
2045         }
2046
2047         while (i < args->n) {
2048                 args->args[i] = 0;
2049                 i++;
2050         }
2051 }
2052
2053 void syscall_get_arguments(struct task_struct *task,
2054         struct pt_regs *regs, unsigned long *args)
2055 {
2056         struct syscall_get_args data = {
2057                 .i = 0,
2058                 .n = 6,
2059                 .args = args,
2060                 .regs = regs,
2061         };
2062
2063         if (task == current)
2064                 unw_init_running(syscall_get_args_cb, &data);
2065         else {
2066                 struct unw_frame_info ufi;
2067                 memset(&ufi, 0, sizeof(ufi));
2068                 unw_init_from_blocked_task(&ufi, task);
2069                 syscall_get_args_cb(&ufi, &data);
2070         }
2071 }