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                 /* Nullified, just crank over the queue. */
  80                 task_regs(task)->iaoq[0] = task_regs(task)->iaoq[1];
  81                 task_regs(task)->iasq[0] = task_regs(task)->iasq[1];
  82                 task_regs(task)->iaoq[1] = task_regs(task)->iaoq[0] + 4;
  83                 pa_psw(task)->n = 0;
  84                 pa_psw(task)->x = 0;
  85                 pa_psw(task)->y = 0;
  86                 pa_psw(task)->z = 0;
  87                 pa_psw(task)->b = 0;
  88                 ptrace_disable(task);
  89                 /* Don't wake up the task, but let the
  90                    parent know something happened. */
  91                 force_sig_fault_to_task(SIGTRAP, TRAP_TRACE,
  92                                         (void __user *) (task_regs(task)->iaoq[0] & ~3),
  93                                         task);
  94                 /* notify_parent(task, SIGCHLD); */
  95                 return;
  96         }
  97
  98         /* Enable recovery counter traps.  The recovery counter
  99          * itself will be set to zero on a task switch.  If the
 100          * task is suspended on a syscall then the syscall return
 101          * path will overwrite the recovery counter with a suitable
 102          * value such that it traps once back in user space.  We
 103          * disable interrupts in the tasks PSW here also, to avoid
 104          * interrupts while the recovery counter is decrementing.
 105          */
 106         pa_psw(task)->r = 1;
 107         pa_psw(task)->t = 0;
 108         pa_psw(task)->h = 0;
 109         pa_psw(task)->l = 0;
 110 }
 111
 112 void user_enable_block_step(struct task_struct *task)
 113 {
 114         clear_tsk_thread_flag(task, TIF_SINGLESTEP);
 115         set_tsk_thread_flag(task, TIF_BLOCKSTEP);
 116
 117         /* Enable taken branch trap. */
 118         pa_psw(task)->r = 0;
 119         pa_psw(task)->t = 1;
 120         pa_psw(task)->h = 0;
 121         pa_psw(task)->l = 0;
 122 }
 123
 124 long arch_ptrace(struct task_struct *child, long request,
 125                  unsigned long addr, unsigned long data)
 126 {
 127         unsigned long __user *datap = (unsigned long __user *)data;
 128         unsigned long tmp;
 129         long ret = -EIO;
 130
 131         switch (request) {
 132
 133         /* Read the word at location addr in the USER area.  For ptraced
 134            processes, the kernel saves all regs on a syscall. */
 135         case PTRACE_PEEKUSR:
 136                 if ((addr & (sizeof(unsigned long)-1)) ||
 137                      addr >= sizeof(struct pt_regs))
 138                         break;
 139                 tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
 140                 ret = put_user(tmp, datap);
 141                 break;
 142
 143         /* Write the word at location addr in the USER area.  This will need
 144            to change when the kernel no longer saves all regs on a syscall.
 145            FIXME.  There is a problem at the moment in that r3-r18 are only
 146            saved if the process is ptraced on syscall entry, and even then
 147            those values are overwritten by actual register values on syscall
 148            exit. */
 149         case PTRACE_POKEUSR:
 150                 /* Some register values written here may be ignored in
 151                  * entry.S:syscall_restore_rfi; e.g. iaoq is written with
 152                  * r31/r31+4, and not with the values in pt_regs.
 153                  */
 154                 if (addr == PT_PSW) {
 155                         /* Allow writing to Nullify, Divide-step-correction,
 156                          * and carry/borrow bits.
 157                          * BEWARE, if you set N, and then single step, it won't
 158                          * stop on the nullified instruction.
 159                          */
 160                         data &= USER_PSW_BITS;
 161                         task_regs(child)->gr[0] &= ~USER_PSW_BITS;
 162                         task_regs(child)->gr[0] |= data;
 163                         ret = 0;
 164                         break;
 165                 }
 166
 167                 if ((addr & (sizeof(unsigned long)-1)) ||
 168                      addr >= sizeof(struct pt_regs))
 169                         break;
 170                 if ((addr >= PT_GR1 && addr <= PT_GR31) ||
 171                                 addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
 172                                 (addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
 173                                 addr == PT_SAR) {
 174                         *(unsigned long *) ((char *) task_regs(child) + addr) = data;
 175                         ret = 0;
 176                 }
 177                 break;
 178
 179         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 180                 return copy_regset_to_user(child,
 181                                            task_user_regset_view(current),
 182                                            REGSET_GENERAL,
 183                                            0, sizeof(struct user_regs_struct),
 184                                            datap);
 185
 186         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 187                 return copy_regset_from_user(child,
 188                                              task_user_regset_view(current),
 189                                              REGSET_GENERAL,
 190                                              0, sizeof(struct user_regs_struct),
 191                                              datap);
 192
 193         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 194                 return copy_regset_to_user(child,
 195                                            task_user_regset_view(current),
 196                                            REGSET_FP,
 197                                            0, sizeof(struct user_fp_struct),
 198                                            datap);
 199
 200         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 201                 return copy_regset_from_user(child,
 202                                              task_user_regset_view(current),
 203                                              REGSET_FP,
 204                                              0, sizeof(struct user_fp_struct),
 205                                              datap);
 206
 207         default:
 208                 ret = ptrace_request(child, request, addr, data);
 209                 break;
 210         }
 211
 212         return ret;
 213 }
 214
 215
 216 #ifdef CONFIG_COMPAT
 217
 218 /* This function is needed to translate 32 bit pt_regs offsets in to
 219  * 64 bit pt_regs offsets.  For example, a 32 bit gdb under a 64 bit kernel
 220  * will request offset 12 if it wants gr3, but the lower 32 bits of
 221  * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4).
 222  * This code relies on a 32 bit pt_regs being comprised of 32 bit values
 223  * except for the fp registers which (a) are 64 bits, and (b) follow
 224  * the gr registers at the start of pt_regs.  The 32 bit pt_regs should
 225  * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[]
 226  * being 64 bit in both cases.
 227  */
 228
 229 static compat_ulong_t translate_usr_offset(compat_ulong_t offset)
 230 {
 231         if (offset < 0)
 232                 return sizeof(struct pt_regs);
 233         else if (offset <= 32*4)        /* gr[0..31] */
 234                 return offset * 2 + 4;
 235         else if (offset <= 32*4+32*8)   /* gr[0..31] + fr[0..31] */
 236                 return offset + 32*4;
 237         else if (offset < sizeof(struct pt_regs)/2 + 32*4)
 238                 return offset * 2 + 4 - 32*8;
 239         else
 240                 return sizeof(struct pt_regs);
 241 }
 242
 243 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 244                         compat_ulong_t addr, compat_ulong_t data)
 245 {
 246         compat_uint_t tmp;
 247         long ret = -EIO;
 248
 249         switch (request) {
 250
 251         case PTRACE_PEEKUSR:
 252                 if (addr & (sizeof(compat_uint_t)-1))
 253                         break;
 254                 addr = translate_usr_offset(addr);
 255                 if (addr >= sizeof(struct pt_regs))
 256                         break;
 257
 258                 tmp = *(compat_uint_t *) ((char *) task_regs(child) + addr);
 259                 ret = put_user(tmp, (compat_uint_t *) (unsigned long) data);
 260                 break;
 261
 262         /* Write the word at location addr in the USER area.  This will need
 263            to change when the kernel no longer saves all regs on a syscall.
 264            FIXME.  There is a problem at the moment in that r3-r18 are only
 265            saved if the process is ptraced on syscall entry, and even then
 266            those values are overwritten by actual register values on syscall
 267            exit. */
 268         case PTRACE_POKEUSR:
 269                 /* Some register values written here may be ignored in
 270                  * entry.S:syscall_restore_rfi; e.g. iaoq is written with
 271                  * r31/r31+4, and not with the values in pt_regs.
 272                  */
 273                 if (addr == PT_PSW) {
 274                         /* Since PT_PSW==0, it is valid for 32 bit processes
 275                          * under 64 bit kernels as well.
 276                          */
 277                         ret = arch_ptrace(child, request, addr, data);
 278                 } else {
 279                         if (addr & (sizeof(compat_uint_t)-1))
 280                                 break;
 281                         addr = translate_usr_offset(addr);
 282                         if (addr >= sizeof(struct pt_regs))
 283                                 break;
 284                         if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
 285                                 /* Special case, fp regs are 64 bits anyway */
 286                                 *(__u64 *) ((char *) task_regs(child) + addr) = data;
 287                                 ret = 0;
 288                         }
 289                         else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
 290                                         addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
 291                                         addr == PT_SAR+4) {
 292                                 /* Zero the top 32 bits */
 293                                 *(__u32 *) ((char *) task_regs(child) + addr - 4) = 0;
 294                                 *(__u32 *) ((char *) task_regs(child) + addr) = data;
 295                                 ret = 0;
 296                         }
 297                 }
 298                 break;
 299
 300         default:
 301                 ret = compat_ptrace_request(child, request, addr, data);
 302                 break;
 303         }
 304
 305         return ret;
 306 }
 307 #endif
 308
 309 long do_syscall_trace_enter(struct pt_regs *regs)
 310 {
 311         if (test_thread_flag(TIF_SYSCALL_TRACE)) {
 312                 int rc = tracehook_report_syscall_entry(regs);
 313
 314                 /*
 315                  * As tracesys_next does not set %r28 to -ENOSYS
 316                  * when %r20 is set to -1, initialize it here.
 317                  */
 318                 regs->gr[28] = -ENOSYS;
 319
 320                 if (rc) {
 321                         /*
 322                          * A nonzero return code from
 323                          * tracehook_report_syscall_entry() tells us
 324                          * to prevent the syscall execution.  Skip
 325                          * the syscall call and the syscall restart handling.
 326                          *
 327                          * Note that the tracer may also just change
 328                          * regs->gr[20] to an invalid syscall number,
 329                          * that is handled by tracesys_next.
 330                          */
 331                         regs->gr[20] = -1UL;
 332                         return -1;
 333                 }
 334         }
 335
 336         /* Do the secure computing check after ptrace. */
 337         if (secure_computing(NULL) == -1)
 338                 return -1;
 339
 340 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 341         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 342                 trace_sys_enter(regs, regs->gr[20]);
 343 #endif
 344
 345 #ifdef CONFIG_64BIT
 346         if (!is_compat_task())
 347                 audit_syscall_entry(regs->gr[20], regs->gr[26], regs->gr[25],
 348                                     regs->gr[24], regs->gr[23]);
 349         else
 350 #endif
 351                 audit_syscall_entry(regs->gr[20] & 0xffffffff,
 352                         regs->gr[26] & 0xffffffff,
 353                         regs->gr[25] & 0xffffffff,
 354                         regs->gr[24] & 0xffffffff,
 355                         regs->gr[23] & 0xffffffff);
 356
 357         /*
 358          * Sign extend the syscall number to 64bit since it may have been
 359          * modified by a compat ptrace call
 360          */
 361         return (int) ((u32) regs->gr[20]);
 362 }
 363
 364 void do_syscall_trace_exit(struct pt_regs *regs)
 365 {
 366         int stepping = test_thread_flag(TIF_SINGLESTEP) ||
 367                 test_thread_flag(TIF_BLOCKSTEP);
 368
 369         audit_syscall_exit(regs);
 370
 371 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 372         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 373                 trace_sys_exit(regs, regs->gr[20]);
 374 #endif
 375
 376         if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
 377                 tracehook_report_syscall_exit(regs, stepping);
 378 }
 379
 380
 381 /*
 382  * regset functions.
 383  */
 384
 385 static int fpr_get(struct task_struct *target,
 386                      const struct user_regset *regset,
 387                      unsigned int pos, unsigned int count,
 388                      void *kbuf, void __user *ubuf)
 389 {
 390         struct pt_regs *regs = task_regs(target);
 391         __u64 *k = kbuf;
 392         __u64 __user *u = ubuf;
 393         __u64 reg;
 394
 395         pos /= sizeof(reg);
 396         count /= sizeof(reg);
 397
 398         if (kbuf)
 399                 for (; count > 0 && pos < ELF_NFPREG; --count)
 400                         *k++ = regs->fr[pos++];
 401         else
 402                 for (; count > 0 && pos < ELF_NFPREG; --count)
 403                         if (__put_user(regs->fr[pos++], u++))
 404                                 return -EFAULT;
 405
 406         kbuf = k;
 407         ubuf = u;
 408         pos *= sizeof(reg);
 409         count *= sizeof(reg);
 410         return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 411                                         ELF_NFPREG * sizeof(reg), -1);
 412 }
 413
 414 static int fpr_set(struct task_struct *target,
 415                      const struct user_regset *regset,
 416                      unsigned int pos, unsigned int count,
 417                      const void *kbuf, const void __user *ubuf)
 418 {
 419         struct pt_regs *regs = task_regs(target);
 420         const __u64 *k = kbuf;
 421         const __u64 __user *u = ubuf;
 422         __u64 reg;
 423
 424         pos /= sizeof(reg);
 425         count /= sizeof(reg);
 426
 427         if (kbuf)
 428                 for (; count > 0 && pos < ELF_NFPREG; --count)
 429                         regs->fr[pos++] = *k++;
 430         else
 431                 for (; count > 0 && pos < ELF_NFPREG; --count) {
 432                         if (__get_user(reg, u++))
 433                                 return -EFAULT;
 434                         regs->fr[pos++] = reg;
 435                 }
 436
 437         kbuf = k;
 438         ubuf = u;
 439         pos *= sizeof(reg);
 440         count *= sizeof(reg);
 441         return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 442                                          ELF_NFPREG * sizeof(reg), -1);
 443 }
 444
 445 #define RI(reg) (offsetof(struct user_regs_struct,reg) / sizeof(long))
 446
 447 static unsigned long get_reg(struct pt_regs *regs, int num)
 448 {
 449         switch (num) {
 450         case RI(gr[0]) ... RI(gr[31]):  return regs->gr[num - RI(gr[0])];
 451         case RI(sr[0]) ... RI(sr[7]):   return regs->sr[num - RI(sr[0])];
 452         case RI(iasq[0]):               return regs->iasq[0];
 453         case RI(iasq[1]):               return regs->iasq[1];
 454         case RI(iaoq[0]):               return regs->iaoq[0];
 455         case RI(iaoq[1]):               return regs->iaoq[1];
 456         case RI(sar):                   return regs->sar;
 457         case RI(iir):                   return regs->iir;
 458         case RI(isr):                   return regs->isr;
 459         case RI(ior):                   return regs->ior;
 460         case RI(ipsw):                  return regs->ipsw;
 461         case RI(cr27):                  return regs->cr27;
 462         case RI(cr0):                   return mfctl(0);
 463         case RI(cr24):                  return mfctl(24);
 464         case RI(cr25):                  return mfctl(25);
 465         case RI(cr26):                  return mfctl(26);
 466         case RI(cr28):                  return mfctl(28);
 467         case RI(cr29):                  return mfctl(29);
 468         case RI(cr30):                  return mfctl(30);
 469         case RI(cr31):                  return mfctl(31);
 470         case RI(cr8):                   return mfctl(8);
 471         case RI(cr9):                   return mfctl(9);
 472         case RI(cr12):                  return mfctl(12);
 473         case RI(cr13):                  return mfctl(13);
 474         case RI(cr10):                  return mfctl(10);
 475         case RI(cr15):                  return mfctl(15);
 476         default:                        return 0;
 477         }
 478 }
 479
 480 static void set_reg(struct pt_regs *regs, int num, unsigned long val)
 481 {
 482         switch (num) {
 483         case RI(gr[0]): /*
 484                          * PSW is in gr[0].
 485                          * Allow writing to Nullify, Divide-step-correction,
 486                          * and carry/borrow bits.
 487                          * BEWARE, if you set N, and then single step, it won't
 488                          * stop on the nullified instruction.
 489                          */
 490                         val &= USER_PSW_BITS;
 491                         regs->gr[0] &= ~USER_PSW_BITS;
 492                         regs->gr[0] |= val;
 493                         return;
 494         case RI(gr[1]) ... RI(gr[31]):
 495                         regs->gr[num - RI(gr[0])] = val;
 496                         return;
 497         case RI(iaoq[0]):
 498         case RI(iaoq[1]):
 499                         regs->iaoq[num - RI(iaoq[0])] = val;
 500                         return;
 501         case RI(sar):   regs->sar = val;
 502                         return;
 503         default:        return;
 504 #if 0
 505         /* do not allow to change any of the following registers (yet) */
 506         case RI(sr[0]) ... RI(sr[7]):   return regs->sr[num - RI(sr[0])];
 507         case RI(iasq[0]):               return regs->iasq[0];
 508         case RI(iasq[1]):               return regs->iasq[1];
 509         case RI(iir):                   return regs->iir;
 510         case RI(isr):                   return regs->isr;
 511         case RI(ior):                   return regs->ior;
 512         case RI(ipsw):                  return regs->ipsw;
 513         case RI(cr27):                  return regs->cr27;
 514         case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31;
 515         case cr8, cr9, cr12, cr13, cr10, cr15;
 516 #endif
 517         }
 518 }
 519
 520 static int gpr_get(struct task_struct *target,
 521                      const struct user_regset *regset,
 522                      unsigned int pos, unsigned int count,
 523                      void *kbuf, void __user *ubuf)
 524 {
 525         struct pt_regs *regs = task_regs(target);
 526         unsigned long *k = kbuf;
 527         unsigned long __user *u = ubuf;
 528         unsigned long reg;
 529
 530         pos /= sizeof(reg);
 531         count /= sizeof(reg);
 532
 533         if (kbuf)
 534                 for (; count > 0 && pos < ELF_NGREG; --count)
 535                         *k++ = get_reg(regs, pos++);
 536         else
 537                 for (; count > 0 && pos < ELF_NGREG; --count)
 538                         if (__put_user(get_reg(regs, pos++), u++))
 539                                 return -EFAULT;
 540         kbuf = k;
 541         ubuf = u;
 542         pos *= sizeof(reg);
 543         count *= sizeof(reg);
 544         return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 545                                         ELF_NGREG * sizeof(reg), -1);
 546 }
 547
 548 static int gpr_set(struct task_struct *target,
 549                      const struct user_regset *regset,
 550                      unsigned int pos, unsigned int count,
 551                      const void *kbuf, const void __user *ubuf)
 552 {
 553         struct pt_regs *regs = task_regs(target);
 554         const unsigned long *k = kbuf;
 555         const unsigned long __user *u = ubuf;
 556         unsigned long reg;
 557
 558         pos /= sizeof(reg);
 559         count /= sizeof(reg);
 560
 561         if (kbuf)
 562                 for (; count > 0 && pos < ELF_NGREG; --count)
 563                         set_reg(regs, pos++, *k++);
 564         else
 565                 for (; count > 0 && pos < ELF_NGREG; --count) {
 566                         if (__get_user(reg, u++))
 567                                 return -EFAULT;
 568                         set_reg(regs, pos++, reg);
 569                 }
 570
 571         kbuf = k;
 572         ubuf = u;
 573         pos *= sizeof(reg);
 574         count *= sizeof(reg);
 575         return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 576                                          ELF_NGREG * sizeof(reg), -1);
 577 }
 578
 579 static const struct user_regset native_regsets[] = {
 580         [REGSET_GENERAL] = {
 581                 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
 582                 .size = sizeof(long), .align = sizeof(long),
 583                 .get = gpr_get, .set = gpr_set
 584         },
 585         [REGSET_FP] = {
 586                 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
 587                 .size = sizeof(__u64), .align = sizeof(__u64),
 588                 .get = fpr_get, .set = fpr_set
 589         }
 590 };
 591
 592 static const struct user_regset_view user_parisc_native_view = {
 593         .name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX,
 594         .regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
 595 };
 596
 597 #ifdef CONFIG_64BIT
 598 #include <linux/compat.h>
 599
 600 static int gpr32_get(struct task_struct *target,
 601                      const struct user_regset *regset,
 602                      unsigned int pos, unsigned int count,
 603                      void *kbuf, void __user *ubuf)
 604 {
 605         struct pt_regs *regs = task_regs(target);
 606         compat_ulong_t *k = kbuf;
 607         compat_ulong_t __user *u = ubuf;
 608         compat_ulong_t reg;
 609
 610         pos /= sizeof(reg);
 611         count /= sizeof(reg);
 612
 613         if (kbuf)
 614                 for (; count > 0 && pos < ELF_NGREG; --count)
 615                         *k++ = get_reg(regs, pos++);
 616         else
 617                 for (; count > 0 && pos < ELF_NGREG; --count)
 618                         if (__put_user((compat_ulong_t) get_reg(regs, pos++), u++))
 619                                 return -EFAULT;
 620
 621         kbuf = k;
 622         ubuf = u;
 623         pos *= sizeof(reg);
 624         count *= sizeof(reg);
 625         return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 626                                         ELF_NGREG * sizeof(reg), -1);
 627 }
 628
 629 static int gpr32_set(struct task_struct *target,
 630                      const struct user_regset *regset,
 631                      unsigned int pos, unsigned int count,
 632                      const void *kbuf, const void __user *ubuf)
 633 {
 634         struct pt_regs *regs = task_regs(target);
 635         const compat_ulong_t *k = kbuf;
 636         const compat_ulong_t __user *u = ubuf;
 637         compat_ulong_t reg;
 638
 639         pos /= sizeof(reg);
 640         count /= sizeof(reg);
 641
 642         if (kbuf)
 643                 for (; count > 0 && pos < ELF_NGREG; --count)
 644                         set_reg(regs, pos++, *k++);
 645         else
 646                 for (; count > 0 && pos < ELF_NGREG; --count) {
 647                         if (__get_user(reg, u++))
 648                                 return -EFAULT;
 649                         set_reg(regs, pos++, reg);
 650                 }
 651
 652         kbuf = k;
 653         ubuf = u;
 654         pos *= sizeof(reg);
 655         count *= sizeof(reg);
 656         return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 657                                          ELF_NGREG * sizeof(reg), -1);
 658 }
 659
 660 /*
 661  * These are the regset flavors matching the 32bit native set.
 662  */
 663 static const struct user_regset compat_regsets[] = {
 664         [REGSET_GENERAL] = {
 665                 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
 666                 .size = sizeof(compat_long_t), .align = sizeof(compat_long_t),
 667                 .get = gpr32_get, .set = gpr32_set
 668         },
 669         [REGSET_FP] = {
 670                 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
 671                 .size = sizeof(__u64), .align = sizeof(__u64),
 672                 .get = fpr_get, .set = fpr_set
 673         }
 674 };
 675
 676 static const struct user_regset_view user_parisc_compat_view = {
 677         .name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX,
 678         .regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
 679 };
 680 #endif  /* CONFIG_64BIT */
 681
 682 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 683 {
 684         BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG);
 685         BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG);
 686 #ifdef CONFIG_64BIT
 687         if (is_compat_task())
 688                 return &user_parisc_compat_view;
 689 #endif
 690         return &user_parisc_native_view;
 691 }
 692
 693
 694 /* HAVE_REGS_AND_STACK_ACCESS_API feature */
 695
 696 struct pt_regs_offset {
 697         const char *name;
 698         int offset;
 699 };
 700
 701 #define REG_OFFSET_NAME(r)    {.name = #r, .offset = offsetof(struct pt_regs, r)}
 702 #define REG_OFFSET_INDEX(r,i) {.name = #r#i, .offset = offsetof(struct pt_regs, r[i])}
 703 #define REG_OFFSET_END {.name = NULL, .offset = 0}
 704
 705 static const struct pt_regs_offset regoffset_table[] = {
 706         REG_OFFSET_INDEX(gr,0),
 707         REG_OFFSET_INDEX(gr,1),
 708         REG_OFFSET_INDEX(gr,2),
 709         REG_OFFSET_INDEX(gr,3),
 710         REG_OFFSET_INDEX(gr,4),
 711         REG_OFFSET_INDEX(gr,5),
 712         REG_OFFSET_INDEX(gr,6),
 713         REG_OFFSET_INDEX(gr,7),
 714         REG_OFFSET_INDEX(gr,8),
 715         REG_OFFSET_INDEX(gr,9),
 716         REG_OFFSET_INDEX(gr,10),
 717         REG_OFFSET_INDEX(gr,11),
 718         REG_OFFSET_INDEX(gr,12),
 719         REG_OFFSET_INDEX(gr,13),
 720         REG_OFFSET_INDEX(gr,14),
 721         REG_OFFSET_INDEX(gr,15),
 722         REG_OFFSET_INDEX(gr,16),
 723         REG_OFFSET_INDEX(gr,17),
 724         REG_OFFSET_INDEX(gr,18),
 725         REG_OFFSET_INDEX(gr,19),
 726         REG_OFFSET_INDEX(gr,20),
 727         REG_OFFSET_INDEX(gr,21),
 728         REG_OFFSET_INDEX(gr,22),
 729         REG_OFFSET_INDEX(gr,23),
 730         REG_OFFSET_INDEX(gr,24),
 731         REG_OFFSET_INDEX(gr,25),
 732         REG_OFFSET_INDEX(gr,26),
 733         REG_OFFSET_INDEX(gr,27),
 734         REG_OFFSET_INDEX(gr,28),
 735         REG_OFFSET_INDEX(gr,29),
 736         REG_OFFSET_INDEX(gr,30),
 737         REG_OFFSET_INDEX(gr,31),
 738         REG_OFFSET_INDEX(sr,0),
 739         REG_OFFSET_INDEX(sr,1),
 740         REG_OFFSET_INDEX(sr,2),
 741         REG_OFFSET_INDEX(sr,3),
 742         REG_OFFSET_INDEX(sr,4),
 743         REG_OFFSET_INDEX(sr,5),
 744         REG_OFFSET_INDEX(sr,6),
 745         REG_OFFSET_INDEX(sr,7),
 746         REG_OFFSET_INDEX(iasq,0),
 747         REG_OFFSET_INDEX(iasq,1),
 748         REG_OFFSET_INDEX(iaoq,0),
 749         REG_OFFSET_INDEX(iaoq,1),
 750         REG_OFFSET_NAME(cr27),
 751         REG_OFFSET_NAME(ksp),
 752         REG_OFFSET_NAME(kpc),
 753         REG_OFFSET_NAME(sar),
 754         REG_OFFSET_NAME(iir),
 755         REG_OFFSET_NAME(isr),
 756         REG_OFFSET_NAME(ior),
 757         REG_OFFSET_NAME(ipsw),
 758         REG_OFFSET_END,
 759 };
 760
 761 /**
 762  * regs_query_register_offset() - query register offset from its name
 763  * @name:       the name of a register
 764  *
 765  * regs_query_register_offset() returns the offset of a register in struct
 766  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 767  */
 768 int regs_query_register_offset(const char *name)
 769 {
 770         const struct pt_regs_offset *roff;
 771         for (roff = regoffset_table; roff->name != NULL; roff++)
 772                 if (!strcmp(roff->name, name))
 773                         return roff->offset;
 774         return -EINVAL;
 775 }
 776
 777 /**
 778  * regs_query_register_name() - query register name from its offset
 779  * @offset:     the offset of a register in struct pt_regs.
 780  *
 781  * regs_query_register_name() returns the name of a register from its
 782  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 783  */
 784 const char *regs_query_register_name(unsigned int offset)
 785 {
 786         const struct pt_regs_offset *roff;
 787         for (roff = regoffset_table; roff->name != NULL; roff++)
 788                 if (roff->offset == offset)
 789                         return roff->name;
 790         return NULL;
 791 }
 792
 793 /**
 794  * regs_within_kernel_stack() - check the address in the stack
 795  * @regs:      pt_regs which contains kernel stack pointer.
 796  * @addr:      address which is checked.
 797  *
 798  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 799  * If @addr is within the kernel stack, it returns true. If not, returns false.
 800  */
 801 int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 802 {
 803         return ((addr & ~(THREAD_SIZE - 1))  ==
 804                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
 805 }
 806
 807 /**
 808  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 809  * @regs:       pt_regs which contains kernel stack pointer.
 810  * @n:          stack entry number.
 811  *
 812  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 813  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 814  * this returns 0.
 815  */
 816 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 817 {
 818         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 819
 820         addr -= n;
 821
 822         if (!regs_within_kernel_stack(regs, (unsigned long)addr))
 823                 return 0;
 824
 825         return *addr;
 826 }