arch/parisc/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) 2000 Hewlett-Packard Co, Linuxcare Inc.
   6  * Copyright (C) 2000 Matthew Wilcox <matthew@wil.cx>
   7  * Copyright (C) 2000 David Huggins-Daines <dhd@debian.org>
   8  * Copyright (C) 2008-2016 Helge Deller <deller@gmx.de>
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/sched.h>
  13 #include <linux/mm.h>
  14 #include <linux/smp.h>
  15 #include <linux/elf.h>
  16 #include <linux/errno.h>
  17 #include <linux/ptrace.h>
  18 #include <linux/tracehook.h>
  19 #include <linux/user.h>
  20 #include <linux/personality.h>
  21 #include <linux/regset.h>
  22 #include <linux/security.h>
  23 #include <linux/seccomp.h>
  24 #include <linux/compat.h>
  25 #include <linux/signal.h>
  26 #include <linux/audit.h>
  27
  28 #include <linux/uaccess.h>
  29 #include <asm/pgtable.h>
  30 #include <asm/processor.h>
  31 #include <asm/asm-offsets.h>
  32
  33 /* PSW bits we allow the debugger to modify */
  34 #define USER_PSW_BITS   (PSW_N | PSW_B | PSW_V | PSW_CB)
  35
  36 #define CREATE_TRACE_POINTS
  37 #include <trace/events/syscalls.h>
  38
  39 /*
  40  * These are our native regset flavors.
  41  */
  42 enum parisc_regset {
  43         REGSET_GENERAL,
  44         REGSET_FP
  45 };
  46
  47 /*
  48  * Called by kernel/ptrace.c when detaching..
  49  *
  50  * Make sure single step bits etc are not set.
  51  */
  52 void ptrace_disable(struct task_struct *task)
  53 {
  54         clear_tsk_thread_flag(task, TIF_SINGLESTEP);
  55         clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
  56
  57         /* make sure the trap bits are not set */
  58         pa_psw(task)->r = 0;
  59         pa_psw(task)->t = 0;
  60         pa_psw(task)->h = 0;
  61         pa_psw(task)->l = 0;
  62 }
  63
  64 /*
  65  * The following functions are called by ptrace_resume() when
  66  * enabling or disabling single/block tracing.
  67  */
  68 void user_disable_single_step(struct task_struct *task)
  69 {
  70         ptrace_disable(task);
  71 }
  72
  73 void user_enable_single_step(struct task_struct *task)
  74 {
  75         clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
  76         set_tsk_thread_flag(task, TIF_SINGLESTEP);
  77
  78         if (pa_psw(task)->n) {
  79                 struct siginfo si;
  80
  81                 /* Nullified, just crank over the queue. */
  82                 task_regs(task)->iaoq[0] = task_regs(task)->iaoq[1];
  83                 task_regs(task)->iasq[0] = task_regs(task)->iasq[1];
  84                 task_regs(task)->iaoq[1] = task_regs(task)->iaoq[0] + 4;
  85                 pa_psw(task)->n = 0;
  86                 pa_psw(task)->x = 0;
  87                 pa_psw(task)->y = 0;
  88                 pa_psw(task)->z = 0;
  89                 pa_psw(task)->b = 0;
  90                 ptrace_disable(task);
  91                 /* Don't wake up the task, but let the
  92                    parent know something happened. */
  93                 si.si_code = TRAP_TRACE;
  94                 si.si_addr = (void __user *) (task_regs(task)->iaoq[0] & ~3);
  95                 si.si_signo = SIGTRAP;
  96                 si.si_errno = 0;
  97                 force_sig_info(SIGTRAP, &si, task);
  98                 /* notify_parent(task, SIGCHLD); */
  99                 return;
 100         }
 101
 102         /* Enable recovery counter traps.  The recovery counter
 103          * itself will be set to zero on a task switch.  If the
 104          * task is suspended on a syscall then the syscall return
 105          * path will overwrite the recovery counter with a suitable
 106          * value such that it traps once back in user space.  We
 107          * disable interrupts in the tasks PSW here also, to avoid
 108          * interrupts while the recovery counter is decrementing.
 109          */
 110         pa_psw(task)->r = 1;
 111         pa_psw(task)->t = 0;
 112         pa_psw(task)->h = 0;
 113         pa_psw(task)->l = 0;
 114 }
 115
 116 void user_enable_block_step(struct task_struct *task)
 117 {
 118         clear_tsk_thread_flag(task, TIF_SINGLESTEP);
 119         set_tsk_thread_flag(task, TIF_BLOCKSTEP);
 120
 121         /* Enable taken branch trap. */
 122         pa_psw(task)->r = 0;
 123         pa_psw(task)->t = 1;
 124         pa_psw(task)->h = 0;
 125         pa_psw(task)->l = 0;
 126 }
 127
 128 long arch_ptrace(struct task_struct *child, long request,
 129                  unsigned long addr, unsigned long data)
 130 {
 131         unsigned long __user *datap = (unsigned long __user *)data;
 132         unsigned long tmp;
 133         long ret = -EIO;
 134
 135         switch (request) {
 136
 137         /* Read the word at location addr in the USER area.  For ptraced
 138            processes, the kernel saves all regs on a syscall. */
 139         case PTRACE_PEEKUSR:
 140                 if ((addr & (sizeof(unsigned long)-1)) ||
 141                      addr >= sizeof(struct pt_regs))
 142                         break;
 143                 tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
 144                 ret = put_user(tmp, datap);
 145                 break;
 146
 147         /* Write the word at location addr in the USER area.  This will need
 148            to change when the kernel no longer saves all regs on a syscall.
 149            FIXME.  There is a problem at the moment in that r3-r18 are only
 150            saved if the process is ptraced on syscall entry, and even then
 151            those values are overwritten by actual register values on syscall
 152            exit. */
 153         case PTRACE_POKEUSR:
 154                 /* Some register values written here may be ignored in
 155                  * entry.S:syscall_restore_rfi; e.g. iaoq is written with
 156                  * r31/r31+4, and not with the values in pt_regs.
 157                  */
 158                 if (addr == PT_PSW) {
 159                         /* Allow writing to Nullify, Divide-step-correction,
 160                          * and carry/borrow bits.
 161                          * BEWARE, if you set N, and then single step, it won't
 162                          * stop on the nullified instruction.
 163                          */
 164                         data &= USER_PSW_BITS;
 165                         task_regs(child)->gr[0] &= ~USER_PSW_BITS;
 166                         task_regs(child)->gr[0] |= data;
 167                         ret = 0;
 168                         break;
 169                 }
 170
 171                 if ((addr & (sizeof(unsigned long)-1)) ||
 172                      addr >= sizeof(struct pt_regs))
 173                         break;
 174                 if ((addr >= PT_GR1 && addr <= PT_GR31) ||
 175                                 addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
 176                                 (addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
 177                                 addr == PT_SAR) {
 178                         *(unsigned long *) ((char *) task_regs(child) + addr) = data;
 179                         ret = 0;
 180                 }
 181                 break;
 182
 183         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 184                 return copy_regset_to_user(child,
 185                                            task_user_regset_view(current),
 186                                            REGSET_GENERAL,
 187                                            0, sizeof(struct user_regs_struct),
 188                                            datap);
 189
 190         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 191                 return copy_regset_from_user(child,
 192                                              task_user_regset_view(current),
 193                                              REGSET_GENERAL,
 194                                              0, sizeof(struct user_regs_struct),
 195                                              datap);
 196
 197         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 198                 return copy_regset_to_user(child,
 199                                            task_user_regset_view(current),
 200                                            REGSET_FP,
 201                                            0, sizeof(struct user_fp_struct),
 202                                            datap);
 203
 204         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 205                 return copy_regset_from_user(child,
 206                                              task_user_regset_view(current),
 207                                              REGSET_FP,
 208                                              0, sizeof(struct user_fp_struct),
 209                                              datap);
 210
 211         default:
 212                 ret = ptrace_request(child, request, addr, data);
 213                 break;
 214         }
 215
 216         return ret;
 217 }
 218
 219
 220 #ifdef CONFIG_COMPAT
 221
 222 /* This function is needed to translate 32 bit pt_regs offsets in to
 223  * 64 bit pt_regs offsets.  For example, a 32 bit gdb under a 64 bit kernel
 224  * will request offset 12 if it wants gr3, but the lower 32 bits of
 225  * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4).
 226  * This code relies on a 32 bit pt_regs being comprised of 32 bit values
 227  * except for the fp registers which (a) are 64 bits, and (b) follow
 228  * the gr registers at the start of pt_regs.  The 32 bit pt_regs should
 229  * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[]
 230  * being 64 bit in both cases.
 231  */
 232
 233 static compat_ulong_t translate_usr_offset(compat_ulong_t offset)
 234 {
 235         if (offset < 0)
 236                 return sizeof(struct pt_regs);
 237         else if (offset <= 32*4)        /* gr[0..31] */
 238                 return offset * 2 + 4;
 239         else if (offset <= 32*4+32*8)   /* gr[0..31] + fr[0..31] */
 240                 return offset + 32*4;
 241         else if (offset < sizeof(struct pt_regs)/2 + 32*4)
 242                 return offset * 2 + 4 - 32*8;
 243         else
 244                 return sizeof(struct pt_regs);
 245 }
 246
 247 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 248                         compat_ulong_t addr, compat_ulong_t data)
 249 {
 250         compat_uint_t tmp;
 251         long ret = -EIO;
 252
 253         switch (request) {
 254
 255         case PTRACE_PEEKUSR:
 256                 if (addr & (sizeof(compat_uint_t)-1))
 257                         break;
 258                 addr = translate_usr_offset(addr);
 259                 if (addr >= sizeof(struct pt_regs))
 260                         break;
 261
 262                 tmp = *(compat_uint_t *) ((char *) task_regs(child) + addr);
 263                 ret = put_user(tmp, (compat_uint_t *) (unsigned long) data);
 264                 break;
 265
 266         /* Write the word at location addr in the USER area.  This will need
 267            to change when the kernel no longer saves all regs on a syscall.
 268            FIXME.  There is a problem at the moment in that r3-r18 are only
 269            saved if the process is ptraced on syscall entry, and even then
 270            those values are overwritten by actual register values on syscall
 271            exit. */
 272         case PTRACE_POKEUSR:
 273                 /* Some register values written here may be ignored in
 274                  * entry.S:syscall_restore_rfi; e.g. iaoq is written with
 275                  * r31/r31+4, and not with the values in pt_regs.
 276                  */
 277                 if (addr == PT_PSW) {
 278                         /* Since PT_PSW==0, it is valid for 32 bit processes
 279                          * under 64 bit kernels as well.
 280                          */
 281                         ret = arch_ptrace(child, request, addr, data);
 282                 } else {
 283                         if (addr & (sizeof(compat_uint_t)-1))
 284                                 break;
 285                         addr = translate_usr_offset(addr);
 286                         if (addr >= sizeof(struct pt_regs))
 287                                 break;
 288                         if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
 289                                 /* Special case, fp regs are 64 bits anyway */
 290                                 *(__u64 *) ((char *) task_regs(child) + addr) = data;
 291                                 ret = 0;
 292                         }
 293                         else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
 294                                         addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
 295                                         addr == PT_SAR+4) {
 296                                 /* Zero the top 32 bits */
 297                                 *(__u32 *) ((char *) task_regs(child) + addr - 4) = 0;
 298                                 *(__u32 *) ((char *) task_regs(child) + addr) = data;
 299                                 ret = 0;
 300                         }
 301                 }
 302                 break;
 303
 304         default:
 305                 ret = compat_ptrace_request(child, request, addr, data);
 306                 break;
 307         }
 308
 309         return ret;
 310 }
 311 #endif
 312
 313 long do_syscall_trace_enter(struct pt_regs *regs)
 314 {
 315         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 316             tracehook_report_syscall_entry(regs)) {
 317                 /*
 318                  * Tracing decided this syscall should not happen or the
 319                  * debugger stored an invalid system call number. Skip
 320                  * the system call and the system call restart handling.
 321                  */
 322                 regs->gr[20] = -1UL;
 323                 goto out;
 324         }
 325
 326         /* Do the secure computing check after ptrace. */
 327         if (secure_computing(NULL) == -1)
 328                 return -1;
 329
 330 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 331         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 332                 trace_sys_enter(regs, regs->gr[20]);
 333 #endif
 334
 335 #ifdef CONFIG_64BIT
 336         if (!is_compat_task())
 337                 audit_syscall_entry(regs->gr[20], regs->gr[26], regs->gr[25],
 338                                     regs->gr[24], regs->gr[23]);
 339         else
 340 #endif
 341                 audit_syscall_entry(regs->gr[20] & 0xffffffff,
 342                         regs->gr[26] & 0xffffffff,
 343                         regs->gr[25] & 0xffffffff,
 344                         regs->gr[24] & 0xffffffff,
 345                         regs->gr[23] & 0xffffffff);
 346
 347 out:
 348         /*
 349          * Sign extend the syscall number to 64bit since it may have been
 350          * modified by a compat ptrace call
 351          */
 352         return (int) ((u32) regs->gr[20]);
 353 }
 354
 355 void do_syscall_trace_exit(struct pt_regs *regs)
 356 {
 357         int stepping = test_thread_flag(TIF_SINGLESTEP) ||
 358                 test_thread_flag(TIF_BLOCKSTEP);
 359
 360         audit_syscall_exit(regs);
 361
 362 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 363         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 364                 trace_sys_exit(regs, regs->gr[20]);
 365 #endif
 366
 367         if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
 368                 tracehook_report_syscall_exit(regs, stepping);
 369 }
 370
 371
 372 /*
 373  * regset functions.
 374  */
 375
 376 static int fpr_get(struct task_struct *target,
 377                      const struct user_regset *regset,
 378                      unsigned int pos, unsigned int count,
 379                      void *kbuf, void __user *ubuf)
 380 {
 381         struct pt_regs *regs = task_regs(target);
 382         __u64 *k = kbuf;
 383         __u64 __user *u = ubuf;
 384         __u64 reg;
 385
 386         pos /= sizeof(reg);
 387         count /= sizeof(reg);
 388
 389         if (kbuf)
 390                 for (; count > 0 && pos < ELF_NFPREG; --count)
 391                         *k++ = regs->fr[pos++];
 392         else
 393                 for (; count > 0 && pos < ELF_NFPREG; --count)
 394                         if (__put_user(regs->fr[pos++], u++))
 395                                 return -EFAULT;
 396
 397         kbuf = k;
 398         ubuf = u;
 399         pos *= sizeof(reg);
 400         count *= sizeof(reg);
 401         return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 402                                         ELF_NFPREG * sizeof(reg), -1);
 403 }
 404
 405 static int fpr_set(struct task_struct *target,
 406                      const struct user_regset *regset,
 407                      unsigned int pos, unsigned int count,
 408                      const void *kbuf, const void __user *ubuf)
 409 {
 410         struct pt_regs *regs = task_regs(target);
 411         const __u64 *k = kbuf;
 412         const __u64 __user *u = ubuf;
 413         __u64 reg;
 414
 415         pos /= sizeof(reg);
 416         count /= sizeof(reg);
 417
 418         if (kbuf)
 419                 for (; count > 0 && pos < ELF_NFPREG; --count)
 420                         regs->fr[pos++] = *k++;
 421         else
 422                 for (; count > 0 && pos < ELF_NFPREG; --count) {
 423                         if (__get_user(reg, u++))
 424                                 return -EFAULT;
 425                         regs->fr[pos++] = reg;
 426                 }
 427
 428         kbuf = k;
 429         ubuf = u;
 430         pos *= sizeof(reg);
 431         count *= sizeof(reg);
 432         return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 433                                          ELF_NFPREG * sizeof(reg), -1);
 434 }
 435
 436 #define RI(reg) (offsetof(struct user_regs_struct,reg) / sizeof(long))
 437
 438 static unsigned long get_reg(struct pt_regs *regs, int num)
 439 {
 440         switch (num) {
 441         case RI(gr[0]) ... RI(gr[31]):  return regs->gr[num - RI(gr[0])];
 442         case RI(sr[0]) ... RI(sr[7]):   return regs->sr[num - RI(sr[0])];
 443         case RI(iasq[0]):               return regs->iasq[0];
 444         case RI(iasq[1]):               return regs->iasq[1];
 445         case RI(iaoq[0]):               return regs->iaoq[0];
 446         case RI(iaoq[1]):               return regs->iaoq[1];
 447         case RI(sar):                   return regs->sar;
 448         case RI(iir):                   return regs->iir;
 449         case RI(isr):                   return regs->isr;
 450         case RI(ior):                   return regs->ior;
 451         case RI(ipsw):                  return regs->ipsw;
 452         case RI(cr27):                  return regs->cr27;
 453         case RI(cr0):                   return mfctl(0);
 454         case RI(cr24):                  return mfctl(24);
 455         case RI(cr25):                  return mfctl(25);
 456         case RI(cr26):                  return mfctl(26);
 457         case RI(cr28):                  return mfctl(28);
 458         case RI(cr29):                  return mfctl(29);
 459         case RI(cr30):                  return mfctl(30);
 460         case RI(cr31):                  return mfctl(31);
 461         case RI(cr8):                   return mfctl(8);
 462         case RI(cr9):                   return mfctl(9);
 463         case RI(cr12):                  return mfctl(12);
 464         case RI(cr13):                  return mfctl(13);
 465         case RI(cr10):                  return mfctl(10);
 466         case RI(cr15):                  return mfctl(15);
 467         default:                        return 0;
 468         }
 469 }
 470
 471 static void set_reg(struct pt_regs *regs, int num, unsigned long val)
 472 {
 473         switch (num) {
 474         case RI(gr[0]): /*
 475                          * PSW is in gr[0].
 476                          * Allow writing to Nullify, Divide-step-correction,
 477                          * and carry/borrow bits.
 478                          * BEWARE, if you set N, and then single step, it won't
 479                          * stop on the nullified instruction.
 480                          */
 481                         val &= USER_PSW_BITS;
 482                         regs->gr[0] &= ~USER_PSW_BITS;
 483                         regs->gr[0] |= val;
 484                         return;
 485         case RI(gr[1]) ... RI(gr[31]):
 486                         regs->gr[num - RI(gr[0])] = val;
 487                         return;
 488         case RI(iaoq[0]):
 489         case RI(iaoq[1]):
 490                         regs->iaoq[num - RI(iaoq[0])] = val;
 491                         return;
 492         case RI(sar):   regs->sar = val;
 493                         return;
 494         default:        return;
 495 #if 0
 496         /* do not allow to change any of the following registers (yet) */
 497         case RI(sr[0]) ... RI(sr[7]):   return regs->sr[num - RI(sr[0])];
 498         case RI(iasq[0]):               return regs->iasq[0];
 499         case RI(iasq[1]):               return regs->iasq[1];
 500         case RI(iir):                   return regs->iir;
 501         case RI(isr):                   return regs->isr;
 502         case RI(ior):                   return regs->ior;
 503         case RI(ipsw):                  return regs->ipsw;
 504         case RI(cr27):                  return regs->cr27;
 505         case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31;
 506         case cr8, cr9, cr12, cr13, cr10, cr15;
 507 #endif
 508         }
 509 }
 510
 511 static int gpr_get(struct task_struct *target,
 512                      const struct user_regset *regset,
 513                      unsigned int pos, unsigned int count,
 514                      void *kbuf, void __user *ubuf)
 515 {
 516         struct pt_regs *regs = task_regs(target);
 517         unsigned long *k = kbuf;
 518         unsigned long __user *u = ubuf;
 519         unsigned long reg;
 520
 521         pos /= sizeof(reg);
 522         count /= sizeof(reg);
 523
 524         if (kbuf)
 525                 for (; count > 0 && pos < ELF_NGREG; --count)
 526                         *k++ = get_reg(regs, pos++);
 527         else
 528                 for (; count > 0 && pos < ELF_NGREG; --count)
 529                         if (__put_user(get_reg(regs, pos++), u++))
 530                                 return -EFAULT;
 531         kbuf = k;
 532         ubuf = u;
 533         pos *= sizeof(reg);
 534         count *= sizeof(reg);
 535         return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 536                                         ELF_NGREG * sizeof(reg), -1);
 537 }
 538
 539 static int gpr_set(struct task_struct *target,
 540                      const struct user_regset *regset,
 541                      unsigned int pos, unsigned int count,
 542                      const void *kbuf, const void __user *ubuf)
 543 {
 544         struct pt_regs *regs = task_regs(target);
 545         const unsigned long *k = kbuf;
 546         const unsigned long __user *u = ubuf;
 547         unsigned long reg;
 548
 549         pos /= sizeof(reg);
 550         count /= sizeof(reg);
 551
 552         if (kbuf)
 553                 for (; count > 0 && pos < ELF_NGREG; --count)
 554                         set_reg(regs, pos++, *k++);
 555         else
 556                 for (; count > 0 && pos < ELF_NGREG; --count) {
 557                         if (__get_user(reg, u++))
 558                                 return -EFAULT;
 559                         set_reg(regs, pos++, reg);
 560                 }
 561
 562         kbuf = k;
 563         ubuf = u;
 564         pos *= sizeof(reg);
 565         count *= sizeof(reg);
 566         return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 567                                          ELF_NGREG * sizeof(reg), -1);
 568 }
 569
 570 static const struct user_regset native_regsets[] = {
 571         [REGSET_GENERAL] = {
 572                 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
 573                 .size = sizeof(long), .align = sizeof(long),
 574                 .get = gpr_get, .set = gpr_set
 575         },
 576         [REGSET_FP] = {
 577                 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
 578                 .size = sizeof(__u64), .align = sizeof(__u64),
 579                 .get = fpr_get, .set = fpr_set
 580         }
 581 };
 582
 583 static const struct user_regset_view user_parisc_native_view = {
 584         .name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX,
 585         .regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
 586 };
 587
 588 #ifdef CONFIG_64BIT
 589 #include <linux/compat.h>
 590
 591 static int gpr32_get(struct task_struct *target,
 592                      const struct user_regset *regset,
 593                      unsigned int pos, unsigned int count,
 594                      void *kbuf, void __user *ubuf)
 595 {
 596         struct pt_regs *regs = task_regs(target);
 597         compat_ulong_t *k = kbuf;
 598         compat_ulong_t __user *u = ubuf;
 599         compat_ulong_t reg;
 600
 601         pos /= sizeof(reg);
 602         count /= sizeof(reg);
 603
 604         if (kbuf)
 605                 for (; count > 0 && pos < ELF_NGREG; --count)
 606                         *k++ = get_reg(regs, pos++);
 607         else
 608                 for (; count > 0 && pos < ELF_NGREG; --count)
 609                         if (__put_user((compat_ulong_t) get_reg(regs, pos++), u++))
 610                                 return -EFAULT;
 611
 612         kbuf = k;
 613         ubuf = u;
 614         pos *= sizeof(reg);
 615         count *= sizeof(reg);
 616         return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 617                                         ELF_NGREG * sizeof(reg), -1);
 618 }
 619
 620 static int gpr32_set(struct task_struct *target,
 621                      const struct user_regset *regset,
 622                      unsigned int pos, unsigned int count,
 623                      const void *kbuf, const void __user *ubuf)
 624 {
 625         struct pt_regs *regs = task_regs(target);
 626         const compat_ulong_t *k = kbuf;
 627         const compat_ulong_t __user *u = ubuf;
 628         compat_ulong_t reg;
 629
 630         pos /= sizeof(reg);
 631         count /= sizeof(reg);
 632
 633         if (kbuf)
 634                 for (; count > 0 && pos < ELF_NGREG; --count)
 635                         set_reg(regs, pos++, *k++);
 636         else
 637                 for (; count > 0 && pos < ELF_NGREG; --count) {
 638                         if (__get_user(reg, u++))
 639                                 return -EFAULT;
 640                         set_reg(regs, pos++, reg);
 641                 }
 642
 643         kbuf = k;
 644         ubuf = u;
 645         pos *= sizeof(reg);
 646         count *= sizeof(reg);
 647         return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 648                                          ELF_NGREG * sizeof(reg), -1);
 649 }
 650
 651 /*
 652  * These are the regset flavors matching the 32bit native set.
 653  */
 654 static const struct user_regset compat_regsets[] = {
 655         [REGSET_GENERAL] = {
 656                 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
 657                 .size = sizeof(compat_long_t), .align = sizeof(compat_long_t),
 658                 .get = gpr32_get, .set = gpr32_set
 659         },
 660         [REGSET_FP] = {
 661                 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
 662                 .size = sizeof(__u64), .align = sizeof(__u64),
 663                 .get = fpr_get, .set = fpr_set
 664         }
 665 };
 666
 667 static const struct user_regset_view user_parisc_compat_view = {
 668         .name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX,
 669         .regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
 670 };
 671 #endif  /* CONFIG_64BIT */
 672
 673 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 674 {
 675         BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG);
 676         BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG);
 677 #ifdef CONFIG_64BIT
 678         if (is_compat_task())
 679                 return &user_parisc_compat_view;
 680 #endif
 681         return &user_parisc_native_view;
 682 }