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/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                 /* Nullified, just crank over the queue. */
  79                 task_regs(task)->iaoq[0] = task_regs(task)->iaoq[1];
  80                 task_regs(task)->iasq[0] = task_regs(task)->iasq[1];
  81                 task_regs(task)->iaoq[1] = task_regs(task)->iaoq[0] + 4;
  82                 pa_psw(task)->n = 0;
  83                 pa_psw(task)->x = 0;
  84                 pa_psw(task)->y = 0;
  85                 pa_psw(task)->z = 0;
  86                 pa_psw(task)->b = 0;
  87                 ptrace_disable(task);
  88                 /* Don't wake up the task, but let the
  89                    parent know something happened. */
  90                 force_sig_fault_to_task(SIGTRAP, TRAP_TRACE,
  91                                         (void __user *) (task_regs(task)->iaoq[0] & ~3),
  92                                         task);
  93                 /* notify_parent(task, SIGCHLD); */
  94                 return;
  95         }
  96
  97         /* Enable recovery counter traps.  The recovery counter
  98          * itself will be set to zero on a task switch.  If the
  99          * task is suspended on a syscall then the syscall return
 100          * path will overwrite the recovery counter with a suitable
 101          * value such that it traps once back in user space.  We
 102          * disable interrupts in the tasks PSW here also, to avoid
 103          * interrupts while the recovery counter is decrementing.
 104          */
 105         pa_psw(task)->r = 1;
 106         pa_psw(task)->t = 0;
 107         pa_psw(task)->h = 0;
 108         pa_psw(task)->l = 0;
 109 }
 110
 111 void user_enable_block_step(struct task_struct *task)
 112 {
 113         clear_tsk_thread_flag(task, TIF_SINGLESTEP);
 114         set_tsk_thread_flag(task, TIF_BLOCKSTEP);
 115
 116         /* Enable taken branch trap. */
 117         pa_psw(task)->r = 0;
 118         pa_psw(task)->t = 1;
 119         pa_psw(task)->h = 0;
 120         pa_psw(task)->l = 0;
 121 }
 122
 123 long arch_ptrace(struct task_struct *child, long request,
 124                  unsigned long addr, unsigned long data)
 125 {
 126         unsigned long __user *datap = (unsigned long __user *)data;
 127         unsigned long tmp;
 128         long ret = -EIO;
 129
 130         switch (request) {
 131
 132         /* Read the word at location addr in the USER area.  For ptraced
 133            processes, the kernel saves all regs on a syscall. */
 134         case PTRACE_PEEKUSR:
 135                 if ((addr & (sizeof(unsigned long)-1)) ||
 136                      addr >= sizeof(struct pt_regs))
 137                         break;
 138                 tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
 139                 ret = put_user(tmp, datap);
 140                 break;
 141
 142         /* Write the word at location addr in the USER area.  This will need
 143            to change when the kernel no longer saves all regs on a syscall.
 144            FIXME.  There is a problem at the moment in that r3-r18 are only
 145            saved if the process is ptraced on syscall entry, and even then
 146            those values are overwritten by actual register values on syscall
 147            exit. */
 148         case PTRACE_POKEUSR:
 149                 /* Some register values written here may be ignored in
 150                  * entry.S:syscall_restore_rfi; e.g. iaoq is written with
 151                  * r31/r31+4, and not with the values in pt_regs.
 152                  */
 153                 if (addr == PT_PSW) {
 154                         /* Allow writing to Nullify, Divide-step-correction,
 155                          * and carry/borrow bits.
 156                          * BEWARE, if you set N, and then single step, it won't
 157                          * stop on the nullified instruction.
 158                          */
 159                         data &= USER_PSW_BITS;
 160                         task_regs(child)->gr[0] &= ~USER_PSW_BITS;
 161                         task_regs(child)->gr[0] |= data;
 162                         ret = 0;
 163                         break;
 164                 }
 165
 166                 if ((addr & (sizeof(unsigned long)-1)) ||
 167                      addr >= sizeof(struct pt_regs))
 168                         break;
 169                 if (addr == PT_IAOQ0 || addr == PT_IAOQ1) {
 170                         data |= 3; /* ensure userspace privilege */
 171                 }
 172                 if ((addr >= PT_GR1 && addr <= PT_GR31) ||
 173                                 addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
 174                                 (addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
 175                                 addr == PT_SAR) {
 176                         *(unsigned long *) ((char *) task_regs(child) + addr) = data;
 177                         ret = 0;
 178                 }
 179                 break;
 180
 181         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 182                 return copy_regset_to_user(child,
 183                                            task_user_regset_view(current),
 184                                            REGSET_GENERAL,
 185                                            0, sizeof(struct user_regs_struct),
 186                                            datap);
 187
 188         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 189                 return copy_regset_from_user(child,
 190                                              task_user_regset_view(current),
 191                                              REGSET_GENERAL,
 192                                              0, sizeof(struct user_regs_struct),
 193                                              datap);
 194
 195         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 196                 return copy_regset_to_user(child,
 197                                            task_user_regset_view(current),
 198                                            REGSET_FP,
 199                                            0, sizeof(struct user_fp_struct),
 200                                            datap);
 201
 202         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 203                 return copy_regset_from_user(child,
 204                                              task_user_regset_view(current),
 205                                              REGSET_FP,
 206                                              0, sizeof(struct user_fp_struct),
 207                                              datap);
 208
 209         default:
 210                 ret = ptrace_request(child, request, addr, data);
 211                 break;
 212         }
 213
 214         return ret;
 215 }
 216
 217
 218 #ifdef CONFIG_COMPAT
 219
 220 /* This function is needed to translate 32 bit pt_regs offsets in to
 221  * 64 bit pt_regs offsets.  For example, a 32 bit gdb under a 64 bit kernel
 222  * will request offset 12 if it wants gr3, but the lower 32 bits of
 223  * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4).
 224  * This code relies on a 32 bit pt_regs being comprised of 32 bit values
 225  * except for the fp registers which (a) are 64 bits, and (b) follow
 226  * the gr registers at the start of pt_regs.  The 32 bit pt_regs should
 227  * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[]
 228  * being 64 bit in both cases.
 229  */
 230
 231 static compat_ulong_t translate_usr_offset(compat_ulong_t offset)
 232 {
 233         compat_ulong_t pos;
 234
 235         if (offset < 32*4)      /* gr[0..31] */
 236                 pos = offset * 2 + 4;
 237         else if (offset < 32*4+32*8)    /* fr[0] ... fr[31] */
 238                 pos = (offset - 32*4) + PT_FR0;
 239         else if (offset < sizeof(struct pt_regs)/2 + 32*4) /* sr[0] ... ipsw */
 240                 pos = (offset - 32*4 - 32*8) * 2 + PT_SR0 + 4;
 241         else
 242                 pos = sizeof(struct pt_regs);
 243
 244         return pos;
 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_IAOQ0+4 || addr == PT_IAOQ1+4) {
 289                                 data |= 3; /* ensure userspace privilege */
 290                         }
 291                         if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
 292                                 /* Special case, fp regs are 64 bits anyway */
 293                                 *(__u32 *) ((char *) task_regs(child) + addr) = data;
 294                                 ret = 0;
 295                         }
 296                         else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
 297                                         addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
 298                                         addr == PT_SAR+4) {
 299                                 /* Zero the top 32 bits */
 300                                 *(__u32 *) ((char *) task_regs(child) + addr - 4) = 0;
 301                                 *(__u32 *) ((char *) task_regs(child) + addr) = data;
 302                                 ret = 0;
 303                         }
 304                 }
 305                 break;
 306
 307         default:
 308                 ret = compat_ptrace_request(child, request, addr, data);
 309                 break;
 310         }
 311
 312         return ret;
 313 }
 314 #endif
 315
 316 long do_syscall_trace_enter(struct pt_regs *regs)
 317 {
 318         if (test_thread_flag(TIF_SYSCALL_TRACE)) {
 319                 int rc = tracehook_report_syscall_entry(regs);
 320
 321                 /*
 322                  * As tracesys_next does not set %r28 to -ENOSYS
 323                  * when %r20 is set to -1, initialize it here.
 324                  */
 325                 regs->gr[28] = -ENOSYS;
 326
 327                 if (rc) {
 328                         /*
 329                          * A nonzero return code from
 330                          * tracehook_report_syscall_entry() tells us
 331                          * to prevent the syscall execution.  Skip
 332                          * the syscall call and the syscall restart handling.
 333                          *
 334                          * Note that the tracer may also just change
 335                          * regs->gr[20] to an invalid syscall number,
 336                          * that is handled by tracesys_next.
 337                          */
 338                         regs->gr[20] = -1UL;
 339                         return -1;
 340                 }
 341         }
 342
 343         /* Do the secure computing check after ptrace. */
 344         if (secure_computing() == -1)
 345                 return -1;
 346
 347 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 348         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 349                 trace_sys_enter(regs, regs->gr[20]);
 350 #endif
 351
 352 #ifdef CONFIG_64BIT
 353         if (!is_compat_task())
 354                 audit_syscall_entry(regs->gr[20], regs->gr[26], regs->gr[25],
 355                                     regs->gr[24], regs->gr[23]);
 356         else
 357 #endif
 358                 audit_syscall_entry(regs->gr[20] & 0xffffffff,
 359                         regs->gr[26] & 0xffffffff,
 360                         regs->gr[25] & 0xffffffff,
 361                         regs->gr[24] & 0xffffffff,
 362                         regs->gr[23] & 0xffffffff);
 363
 364         /*
 365          * Sign extend the syscall number to 64bit since it may have been
 366          * modified by a compat ptrace call
 367          */
 368         return (int) ((u32) regs->gr[20]);
 369 }
 370
 371 void do_syscall_trace_exit(struct pt_regs *regs)
 372 {
 373         int stepping = test_thread_flag(TIF_SINGLESTEP) ||
 374                 test_thread_flag(TIF_BLOCKSTEP);
 375
 376         audit_syscall_exit(regs);
 377
 378 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 379         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 380                 trace_sys_exit(regs, regs->gr[20]);
 381 #endif
 382
 383         if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
 384                 tracehook_report_syscall_exit(regs, stepping);
 385 }
 386
 387
 388 /*
 389  * regset functions.
 390  */
 391
 392 static int fpr_get(struct task_struct *target,
 393                      const struct user_regset *regset,
 394                      struct membuf to)
 395 {
 396         struct pt_regs *regs = task_regs(target);
 397
 398         return membuf_write(&to, regs->fr, ELF_NFPREG * sizeof(__u64));
 399 }
 400
 401 static int fpr_set(struct task_struct *target,
 402                      const struct user_regset *regset,
 403                      unsigned int pos, unsigned int count,
 404                      const void *kbuf, const void __user *ubuf)
 405 {
 406         struct pt_regs *regs = task_regs(target);
 407         const __u64 *k = kbuf;
 408         const __u64 __user *u = ubuf;
 409         __u64 reg;
 410
 411         pos /= sizeof(reg);
 412         count /= sizeof(reg);
 413
 414         if (kbuf)
 415                 for (; count > 0 && pos < ELF_NFPREG; --count)
 416                         regs->fr[pos++] = *k++;
 417         else
 418                 for (; count > 0 && pos < ELF_NFPREG; --count) {
 419                         if (__get_user(reg, u++))
 420                                 return -EFAULT;
 421                         regs->fr[pos++] = reg;
 422                 }
 423
 424         kbuf = k;
 425         ubuf = u;
 426         pos *= sizeof(reg);
 427         count *= sizeof(reg);
 428         return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 429                                          ELF_NFPREG * sizeof(reg), -1);
 430 }
 431
 432 #define RI(reg) (offsetof(struct user_regs_struct,reg) / sizeof(long))
 433
 434 static unsigned long get_reg(struct pt_regs *regs, int num)
 435 {
 436         switch (num) {
 437         case RI(gr[0]) ... RI(gr[31]):  return regs->gr[num - RI(gr[0])];
 438         case RI(sr[0]) ... RI(sr[7]):   return regs->sr[num - RI(sr[0])];
 439         case RI(iasq[0]):               return regs->iasq[0];
 440         case RI(iasq[1]):               return regs->iasq[1];
 441         case RI(iaoq[0]):               return regs->iaoq[0];
 442         case RI(iaoq[1]):               return regs->iaoq[1];
 443         case RI(sar):                   return regs->sar;
 444         case RI(iir):                   return regs->iir;
 445         case RI(isr):                   return regs->isr;
 446         case RI(ior):                   return regs->ior;
 447         case RI(ipsw):                  return regs->ipsw;
 448         case RI(cr27):                  return regs->cr27;
 449         case RI(cr0):                   return mfctl(0);
 450         case RI(cr24):                  return mfctl(24);
 451         case RI(cr25):                  return mfctl(25);
 452         case RI(cr26):                  return mfctl(26);
 453         case RI(cr28):                  return mfctl(28);
 454         case RI(cr29):                  return mfctl(29);
 455         case RI(cr30):                  return mfctl(30);
 456         case RI(cr31):                  return mfctl(31);
 457         case RI(cr8):                   return mfctl(8);
 458         case RI(cr9):                   return mfctl(9);
 459         case RI(cr12):                  return mfctl(12);
 460         case RI(cr13):                  return mfctl(13);
 461         case RI(cr10):                  return mfctl(10);
 462         case RI(cr15):                  return mfctl(15);
 463         default:                        return 0;
 464         }
 465 }
 466
 467 static void set_reg(struct pt_regs *regs, int num, unsigned long val)
 468 {
 469         switch (num) {
 470         case RI(gr[0]): /*
 471                          * PSW is in gr[0].
 472                          * Allow writing to Nullify, Divide-step-correction,
 473                          * and carry/borrow bits.
 474                          * BEWARE, if you set N, and then single step, it won't
 475                          * stop on the nullified instruction.
 476                          */
 477                         val &= USER_PSW_BITS;
 478                         regs->gr[0] &= ~USER_PSW_BITS;
 479                         regs->gr[0] |= val;
 480                         return;
 481         case RI(gr[1]) ... RI(gr[31]):
 482                         regs->gr[num - RI(gr[0])] = val;
 483                         return;
 484         case RI(iaoq[0]):
 485         case RI(iaoq[1]):
 486                         /* set 2 lowest bits to ensure userspace privilege: */
 487                         regs->iaoq[num - RI(iaoq[0])] = val | 3;
 488                         return;
 489         case RI(sar):   regs->sar = val;
 490                         return;
 491         default:        return;
 492 #if 0
 493         /* do not allow to change any of the following registers (yet) */
 494         case RI(sr[0]) ... RI(sr[7]):   return regs->sr[num - RI(sr[0])];
 495         case RI(iasq[0]):               return regs->iasq[0];
 496         case RI(iasq[1]):               return regs->iasq[1];
 497         case RI(iir):                   return regs->iir;
 498         case RI(isr):                   return regs->isr;
 499         case RI(ior):                   return regs->ior;
 500         case RI(ipsw):                  return regs->ipsw;
 501         case RI(cr27):                  return regs->cr27;
 502         case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31;
 503         case cr8, cr9, cr12, cr13, cr10, cr15;
 504 #endif
 505         }
 506 }
 507
 508 static int gpr_get(struct task_struct *target,
 509                      const struct user_regset *regset,
 510                      struct membuf to)
 511 {
 512         struct pt_regs *regs = task_regs(target);
 513         unsigned int pos;
 514
 515         for (pos = 0; pos < ELF_NGREG; pos++)
 516                 membuf_store(&to, get_reg(regs, pos));
 517         return 0;
 518 }
 519
 520 static int gpr_set(struct task_struct *target,
 521                      const struct user_regset *regset,
 522                      unsigned int pos, unsigned int count,
 523                      const void *kbuf, const void __user *ubuf)
 524 {
 525         struct pt_regs *regs = task_regs(target);
 526         const unsigned long *k = kbuf;
 527         const 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                         set_reg(regs, pos++, *k++);
 536         else
 537                 for (; count > 0 && pos < ELF_NGREG; --count) {
 538                         if (__get_user(reg, u++))
 539                                 return -EFAULT;
 540                         set_reg(regs, pos++, reg);
 541                 }
 542
 543         kbuf = k;
 544         ubuf = u;
 545         pos *= sizeof(reg);
 546         count *= sizeof(reg);
 547         return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 548                                          ELF_NGREG * sizeof(reg), -1);
 549 }
 550
 551 static const struct user_regset native_regsets[] = {
 552         [REGSET_GENERAL] = {
 553                 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
 554                 .size = sizeof(long), .align = sizeof(long),
 555                 .regset_get = gpr_get, .set = gpr_set
 556         },
 557         [REGSET_FP] = {
 558                 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
 559                 .size = sizeof(__u64), .align = sizeof(__u64),
 560                 .regset_get = fpr_get, .set = fpr_set
 561         }
 562 };
 563
 564 static const struct user_regset_view user_parisc_native_view = {
 565         .name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX,
 566         .regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
 567 };
 568
 569 #ifdef CONFIG_64BIT
 570 static int gpr32_get(struct task_struct *target,
 571                      const struct user_regset *regset,
 572                      struct membuf to)
 573 {
 574         struct pt_regs *regs = task_regs(target);
 575         unsigned int pos;
 576
 577         for (pos = 0; pos < ELF_NGREG; pos++)
 578                 membuf_store(&to, (compat_ulong_t)get_reg(regs, pos));
 579
 580         return 0;
 581 }
 582
 583 static int gpr32_set(struct task_struct *target,
 584                      const struct user_regset *regset,
 585                      unsigned int pos, unsigned int count,
 586                      const void *kbuf, const void __user *ubuf)
 587 {
 588         struct pt_regs *regs = task_regs(target);
 589         const compat_ulong_t *k = kbuf;
 590         const compat_ulong_t __user *u = ubuf;
 591         compat_ulong_t reg;
 592
 593         pos /= sizeof(reg);
 594         count /= sizeof(reg);
 595
 596         if (kbuf)
 597                 for (; count > 0 && pos < ELF_NGREG; --count)
 598                         set_reg(regs, pos++, *k++);
 599         else
 600                 for (; count > 0 && pos < ELF_NGREG; --count) {
 601                         if (__get_user(reg, u++))
 602                                 return -EFAULT;
 603                         set_reg(regs, pos++, reg);
 604                 }
 605
 606         kbuf = k;
 607         ubuf = u;
 608         pos *= sizeof(reg);
 609         count *= sizeof(reg);
 610         return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 611                                          ELF_NGREG * sizeof(reg), -1);
 612 }
 613
 614 /*
 615  * These are the regset flavors matching the 32bit native set.
 616  */
 617 static const struct user_regset compat_regsets[] = {
 618         [REGSET_GENERAL] = {
 619                 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
 620                 .size = sizeof(compat_long_t), .align = sizeof(compat_long_t),
 621                 .regset_get = gpr32_get, .set = gpr32_set
 622         },
 623         [REGSET_FP] = {
 624                 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
 625                 .size = sizeof(__u64), .align = sizeof(__u64),
 626                 .regset_get = fpr_get, .set = fpr_set
 627         }
 628 };
 629
 630 static const struct user_regset_view user_parisc_compat_view = {
 631         .name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX,
 632         .regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
 633 };
 634 #endif  /* CONFIG_64BIT */
 635
 636 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 637 {
 638         BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG);
 639         BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG);
 640 #ifdef CONFIG_64BIT
 641         if (is_compat_task())
 642                 return &user_parisc_compat_view;
 643 #endif
 644         return &user_parisc_native_view;
 645 }
 646
 647
 648 /* HAVE_REGS_AND_STACK_ACCESS_API feature */
 649
 650 struct pt_regs_offset {
 651         const char *name;
 652         int offset;
 653 };
 654
 655 #define REG_OFFSET_NAME(r)    {.name = #r, .offset = offsetof(struct pt_regs, r)}
 656 #define REG_OFFSET_INDEX(r,i) {.name = #r#i, .offset = offsetof(struct pt_regs, r[i])}
 657 #define REG_OFFSET_END {.name = NULL, .offset = 0}
 658
 659 static const struct pt_regs_offset regoffset_table[] = {
 660         REG_OFFSET_INDEX(gr,0),
 661         REG_OFFSET_INDEX(gr,1),
 662         REG_OFFSET_INDEX(gr,2),
 663         REG_OFFSET_INDEX(gr,3),
 664         REG_OFFSET_INDEX(gr,4),
 665         REG_OFFSET_INDEX(gr,5),
 666         REG_OFFSET_INDEX(gr,6),
 667         REG_OFFSET_INDEX(gr,7),
 668         REG_OFFSET_INDEX(gr,8),
 669         REG_OFFSET_INDEX(gr,9),
 670         REG_OFFSET_INDEX(gr,10),
 671         REG_OFFSET_INDEX(gr,11),
 672         REG_OFFSET_INDEX(gr,12),
 673         REG_OFFSET_INDEX(gr,13),
 674         REG_OFFSET_INDEX(gr,14),
 675         REG_OFFSET_INDEX(gr,15),
 676         REG_OFFSET_INDEX(gr,16),
 677         REG_OFFSET_INDEX(gr,17),
 678         REG_OFFSET_INDEX(gr,18),
 679         REG_OFFSET_INDEX(gr,19),
 680         REG_OFFSET_INDEX(gr,20),
 681         REG_OFFSET_INDEX(gr,21),
 682         REG_OFFSET_INDEX(gr,22),
 683         REG_OFFSET_INDEX(gr,23),
 684         REG_OFFSET_INDEX(gr,24),
 685         REG_OFFSET_INDEX(gr,25),
 686         REG_OFFSET_INDEX(gr,26),
 687         REG_OFFSET_INDEX(gr,27),
 688         REG_OFFSET_INDEX(gr,28),
 689         REG_OFFSET_INDEX(gr,29),
 690         REG_OFFSET_INDEX(gr,30),
 691         REG_OFFSET_INDEX(gr,31),
 692         REG_OFFSET_INDEX(sr,0),
 693         REG_OFFSET_INDEX(sr,1),
 694         REG_OFFSET_INDEX(sr,2),
 695         REG_OFFSET_INDEX(sr,3),
 696         REG_OFFSET_INDEX(sr,4),
 697         REG_OFFSET_INDEX(sr,5),
 698         REG_OFFSET_INDEX(sr,6),
 699         REG_OFFSET_INDEX(sr,7),
 700         REG_OFFSET_INDEX(iasq,0),
 701         REG_OFFSET_INDEX(iasq,1),
 702         REG_OFFSET_INDEX(iaoq,0),
 703         REG_OFFSET_INDEX(iaoq,1),
 704         REG_OFFSET_NAME(cr27),
 705         REG_OFFSET_NAME(ksp),
 706         REG_OFFSET_NAME(kpc),
 707         REG_OFFSET_NAME(sar),
 708         REG_OFFSET_NAME(iir),
 709         REG_OFFSET_NAME(isr),
 710         REG_OFFSET_NAME(ior),
 711         REG_OFFSET_NAME(ipsw),
 712         REG_OFFSET_END,
 713 };
 714
 715 /**
 716  * regs_query_register_offset() - query register offset from its name
 717  * @name:       the name of a register
 718  *
 719  * regs_query_register_offset() returns the offset of a register in struct
 720  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 721  */
 722 int regs_query_register_offset(const char *name)
 723 {
 724         const struct pt_regs_offset *roff;
 725         for (roff = regoffset_table; roff->name != NULL; roff++)
 726                 if (!strcmp(roff->name, name))
 727                         return roff->offset;
 728         return -EINVAL;
 729 }
 730
 731 /**
 732  * regs_query_register_name() - query register name from its offset
 733  * @offset:     the offset of a register in struct pt_regs.
 734  *
 735  * regs_query_register_name() returns the name of a register from its
 736  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 737  */
 738 const char *regs_query_register_name(unsigned int offset)
 739 {
 740         const struct pt_regs_offset *roff;
 741         for (roff = regoffset_table; roff->name != NULL; roff++)
 742                 if (roff->offset == offset)
 743                         return roff->name;
 744         return NULL;
 745 }
 746
 747 /**
 748  * regs_within_kernel_stack() - check the address in the stack
 749  * @regs:      pt_regs which contains kernel stack pointer.
 750  * @addr:      address which is checked.
 751  *
 752  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 753  * If @addr is within the kernel stack, it returns true. If not, returns false.
 754  */
 755 int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 756 {
 757         return ((addr & ~(THREAD_SIZE - 1))  ==
 758                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
 759 }
 760
 761 /**
 762  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 763  * @regs:       pt_regs which contains kernel stack pointer.
 764  * @n:          stack entry number.
 765  *
 766  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 767  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 768  * this returns 0.
 769  */
 770 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 771 {
 772         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 773
 774         addr -= n;
 775
 776         if (!regs_within_kernel_stack(regs, (unsigned long)addr))
 777                 return 0;
 778
 779         return *addr;
 780 }