arch/parisc/kernel/ptrace.c

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