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/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 <linux/uaccess.h>
  28 #include <asm/processor.h>
  29 #include <asm/asm-offsets.h>
  30
  31 /* PSW bits we allow the debugger to modify */
  32 #define USER_PSW_BITS   (PSW_N | PSW_B | PSW_V | PSW_CB)
  33
  34 #define CREATE_TRACE_POINTS
  35 #include <trace/events/syscalls.h>
  36
  37 /*
  38  * These are our native regset flavors.
  39  */
  40 enum parisc_regset {
  41         REGSET_GENERAL,
  42         REGSET_FP
  43 };
  44
  45 /*
  46  * Called by kernel/ptrace.c when detaching..
  47  *
  48  * Make sure single step bits etc are not set.
  49  */
  50 void ptrace_disable(struct task_struct *task)
  51 {
  52         clear_tsk_thread_flag(task, TIF_SINGLESTEP);
  53         clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
  54
  55         /* make sure the trap bits are not set */
  56         pa_psw(task)->r = 0;
  57         pa_psw(task)->t = 0;
  58         pa_psw(task)->h = 0;
  59         pa_psw(task)->l = 0;
  60 }
  61
  62 /*
  63  * The following functions are called by ptrace_resume() when
  64  * enabling or disabling single/block tracing.
  65  */
  66 void user_disable_single_step(struct task_struct *task)
  67 {
  68         ptrace_disable(task);
  69 }
  70
  71 void user_enable_single_step(struct task_struct *task)
  72 {
  73         clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
  74         set_tsk_thread_flag(task, TIF_SINGLESTEP);
  75
  76         if (pa_psw(task)->n) {
  77                 /* Nullified, just crank over the queue. */
  78                 task_regs(task)->iaoq[0] = task_regs(task)->iaoq[1];
  79                 task_regs(task)->iasq[0] = task_regs(task)->iasq[1];
  80                 task_regs(task)->iaoq[1] = task_regs(task)->iaoq[0] + 4;
  81                 pa_psw(task)->n = 0;
  82                 pa_psw(task)->x = 0;
  83                 pa_psw(task)->y = 0;
  84                 pa_psw(task)->z = 0;
  85                 pa_psw(task)->b = 0;
  86                 ptrace_disable(task);
  87                 /* Don't wake up the task, but let the
  88                    parent know something happened. */
  89                 force_sig_fault_to_task(SIGTRAP, TRAP_TRACE,
  90                                         (void __user *) (task_regs(task)->iaoq[0] & ~3),
  91                                         task);
  92                 /* notify_parent(task, SIGCHLD); */
  93                 return;
  94         }
  95
  96         /* Enable recovery counter traps.  The recovery counter
  97          * itself will be set to zero on a task switch.  If the
  98          * task is suspended on a syscall then the syscall return
  99          * path will overwrite the recovery counter with a suitable
 100          * value such that it traps once back in user space.  We
 101          * disable interrupts in the tasks PSW here also, to avoid
 102          * interrupts while the recovery counter is decrementing.
 103          */
 104         pa_psw(task)->r = 1;
 105         pa_psw(task)->t = 0;
 106         pa_psw(task)->h = 0;
 107         pa_psw(task)->l = 0;
 108 }
 109
 110 void user_enable_block_step(struct task_struct *task)
 111 {
 112         clear_tsk_thread_flag(task, TIF_SINGLESTEP);
 113         set_tsk_thread_flag(task, TIF_BLOCKSTEP);
 114
 115         /* Enable taken branch trap. */
 116         pa_psw(task)->r = 0;
 117         pa_psw(task)->t = 1;
 118         pa_psw(task)->h = 0;
 119         pa_psw(task)->l = 0;
 120 }
 121
 122 long arch_ptrace(struct task_struct *child, long request,
 123                  unsigned long addr, unsigned long data)
 124 {
 125         unsigned long __user *datap = (unsigned long __user *)data;
 126         unsigned long tmp;
 127         long ret = -EIO;
 128
 129         unsigned long user_regs_struct_size = sizeof(struct user_regs_struct);
 130 #ifdef CONFIG_64BIT
 131         if (is_compat_task())
 132                 user_regs_struct_size /= 2;
 133 #endif
 134
 135         switch (request) {
 136
 137         /* Read the word at location addr in the USER area.  For ptraced
 138            processes, the kernel saves all regs on a syscall. */
 139         case PTRACE_PEEKUSR:
 140                 if ((addr & (sizeof(unsigned long)-1)) ||
 141                      addr >= sizeof(struct pt_regs))
 142                         break;
 143                 tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
 144                 ret = put_user(tmp, datap);
 145                 break;
 146
 147         /* Write the word at location addr in the USER area.  This will need
 148            to change when the kernel no longer saves all regs on a syscall.
 149            FIXME.  There is a problem at the moment in that r3-r18 are only
 150            saved if the process is ptraced on syscall entry, and even then
 151            those values are overwritten by actual register values on syscall
 152            exit. */
 153         case PTRACE_POKEUSR:
 154                 /* Some register values written here may be ignored in
 155                  * entry.S:syscall_restore_rfi; e.g. iaoq is written with
 156                  * r31/r31+4, and not with the values in pt_regs.
 157                  */
 158                 if (addr == PT_PSW) {
 159                         /* Allow writing to Nullify, Divide-step-correction,
 160                          * and carry/borrow bits.
 161                          * BEWARE, if you set N, and then single step, it won't
 162                          * stop on the nullified instruction.
 163                          */
 164                         data &= USER_PSW_BITS;
 165                         task_regs(child)->gr[0] &= ~USER_PSW_BITS;
 166                         task_regs(child)->gr[0] |= data;
 167                         ret = 0;
 168                         break;
 169                 }
 170
 171                 if ((addr & (sizeof(unsigned long)-1)) ||
 172                      addr >= sizeof(struct pt_regs))
 173                         break;
 174                 if (addr == PT_IAOQ0 || addr == PT_IAOQ1) {
 175                         data |= PRIV_USER; /* ensure userspace privilege */
 176                 }
 177                 if ((addr >= PT_GR1 && addr <= PT_GR31) ||
 178                                 addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
 179                                 (addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
 180                                 addr == PT_SAR) {
 181                         *(unsigned long *) ((char *) task_regs(child) + addr) = data;
 182                         ret = 0;
 183                 }
 184                 break;
 185
 186         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 187                 return copy_regset_to_user(child,
 188                                            task_user_regset_view(current),
 189                                            REGSET_GENERAL,
 190                                            0, user_regs_struct_size,
 191                                            datap);
 192
 193         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 194                 return copy_regset_from_user(child,
 195                                              task_user_regset_view(current),
 196                                              REGSET_GENERAL,
 197                                              0, user_regs_struct_size,
 198                                              datap);
 199
 200         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 201                 return copy_regset_to_user(child,
 202                                            task_user_regset_view(current),
 203                                            REGSET_FP,
 204                                            0, sizeof(struct user_fp_struct),
 205                                            datap);
 206
 207         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 208                 return copy_regset_from_user(child,
 209                                              task_user_regset_view(current),
 210                                              REGSET_FP,
 211                                              0, sizeof(struct user_fp_struct),
 212                                              datap);
 213
 214         default:
 215                 ret = ptrace_request(child, request, addr, data);
 216                 break;
 217         }
 218
 219         return ret;
 220 }
 221
 222
 223 #ifdef CONFIG_COMPAT
 224
 225 /* This function is needed to translate 32 bit pt_regs offsets in to
 226  * 64 bit pt_regs offsets.  For example, a 32 bit gdb under a 64 bit kernel
 227  * will request offset 12 if it wants gr3, but the lower 32 bits of
 228  * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4).
 229  * This code relies on a 32 bit pt_regs being comprised of 32 bit values
 230  * except for the fp registers which (a) are 64 bits, and (b) follow
 231  * the gr registers at the start of pt_regs.  The 32 bit pt_regs should
 232  * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[]
 233  * being 64 bit in both cases.
 234  */
 235
 236 static compat_ulong_t translate_usr_offset(compat_ulong_t offset)
 237 {
 238         compat_ulong_t pos;
 239
 240         if (offset < 32*4)      /* gr[0..31] */
 241                 pos = offset * 2 + 4;
 242         else if (offset < 32*4+32*8)    /* fr[0] ... fr[31] */
 243                 pos = (offset - 32*4) + PT_FR0;
 244         else if (offset < sizeof(struct pt_regs)/2 + 32*4) /* sr[0] ... ipsw */
 245                 pos = (offset - 32*4 - 32*8) * 2 + PT_SR0 + 4;
 246         else
 247                 pos = sizeof(struct pt_regs);
 248
 249         return pos;
 250 }
 251
 252 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 253                         compat_ulong_t addr, compat_ulong_t data)
 254 {
 255         compat_uint_t tmp;
 256         long ret = -EIO;
 257
 258         switch (request) {
 259
 260         case PTRACE_PEEKUSR:
 261                 if (addr & (sizeof(compat_uint_t)-1))
 262                         break;
 263                 addr = translate_usr_offset(addr);
 264                 if (addr >= sizeof(struct pt_regs))
 265                         break;
 266
 267                 tmp = *(compat_uint_t *) ((char *) task_regs(child) + addr);
 268                 ret = put_user(tmp, (compat_uint_t *) (unsigned long) data);
 269                 break;
 270
 271         /* Write the word at location addr in the USER area.  This will need
 272            to change when the kernel no longer saves all regs on a syscall.
 273            FIXME.  There is a problem at the moment in that r3-r18 are only
 274            saved if the process is ptraced on syscall entry, and even then
 275            those values are overwritten by actual register values on syscall
 276            exit. */
 277         case PTRACE_POKEUSR:
 278                 /* Some register values written here may be ignored in
 279                  * entry.S:syscall_restore_rfi; e.g. iaoq is written with
 280                  * r31/r31+4, and not with the values in pt_regs.
 281                  */
 282                 if (addr == PT_PSW) {
 283                         /* Since PT_PSW==0, it is valid for 32 bit processes
 284                          * under 64 bit kernels as well.
 285                          */
 286                         ret = arch_ptrace(child, request, addr, data);
 287                 } else {
 288                         if (addr & (sizeof(compat_uint_t)-1))
 289                                 break;
 290                         addr = translate_usr_offset(addr);
 291                         if (addr >= sizeof(struct pt_regs))
 292                                 break;
 293                         if (addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4) {
 294                                 data |= PRIV_USER; /* ensure userspace privilege */
 295                         }
 296                         if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
 297                                 /* Special case, fp regs are 64 bits anyway */
 298                                 *(__u32 *) ((char *) task_regs(child) + addr) = data;
 299                                 ret = 0;
 300                         }
 301                         else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
 302                                         addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
 303                                         addr == PT_SAR+4) {
 304                                 /* Zero the top 32 bits */
 305                                 *(__u32 *) ((char *) task_regs(child) + addr - 4) = 0;
 306                                 *(__u32 *) ((char *) task_regs(child) + addr) = data;
 307                                 ret = 0;
 308                         }
 309                 }
 310                 break;
 311         case PTRACE_GETREGS:
 312         case PTRACE_SETREGS:
 313         case PTRACE_GETFPREGS:
 314         case PTRACE_SETFPREGS:
 315                 return arch_ptrace(child, request, addr, data);
 316
 317         default:
 318                 ret = compat_ptrace_request(child, request, addr, data);
 319                 break;
 320         }
 321
 322         return ret;
 323 }
 324 #endif
 325
 326 long do_syscall_trace_enter(struct pt_regs *regs)
 327 {
 328         if (test_thread_flag(TIF_SYSCALL_TRACE)) {
 329                 int rc = ptrace_report_syscall_entry(regs);
 330
 331                 /*
 332                  * As tracesys_next does not set %r28 to -ENOSYS
 333                  * when %r20 is set to -1, initialize it here.
 334                  */
 335                 regs->gr[28] = -ENOSYS;
 336
 337                 if (rc) {
 338                         /*
 339                          * A nonzero return code from
 340                          * ptrace_report_syscall_entry() tells us
 341                          * to prevent the syscall execution.  Skip
 342                          * the syscall call and the syscall restart handling.
 343                          *
 344                          * Note that the tracer may also just change
 345                          * regs->gr[20] to an invalid syscall number,
 346                          * that is handled by tracesys_next.
 347                          */
 348                         regs->gr[20] = -1UL;
 349                         return -1;
 350                 }
 351         }
 352
 353         /* Do the secure computing check after ptrace. */
 354         if (secure_computing() == -1)
 355                 return -1;
 356
 357 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 358         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 359                 trace_sys_enter(regs, regs->gr[20]);
 360 #endif
 361
 362 #ifdef CONFIG_64BIT
 363         if (!is_compat_task())
 364                 audit_syscall_entry(regs->gr[20], regs->gr[26], regs->gr[25],
 365                                     regs->gr[24], regs->gr[23]);
 366         else
 367 #endif
 368                 audit_syscall_entry(regs->gr[20] & 0xffffffff,
 369                         regs->gr[26] & 0xffffffff,
 370                         regs->gr[25] & 0xffffffff,
 371                         regs->gr[24] & 0xffffffff,
 372                         regs->gr[23] & 0xffffffff);
 373
 374         /*
 375          * Sign extend the syscall number to 64bit since it may have been
 376          * modified by a compat ptrace call
 377          */
 378         return (int) ((u32) regs->gr[20]);
 379 }
 380
 381 void do_syscall_trace_exit(struct pt_regs *regs)
 382 {
 383         int stepping = test_thread_flag(TIF_SINGLESTEP) ||
 384                 test_thread_flag(TIF_BLOCKSTEP);
 385
 386         audit_syscall_exit(regs);
 387
 388 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 389         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 390                 trace_sys_exit(regs, regs->gr[20]);
 391 #endif
 392
 393         if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
 394                 ptrace_report_syscall_exit(regs, stepping);
 395 }
 396
 397
 398 /*
 399  * regset functions.
 400  */
 401
 402 static int fpr_get(struct task_struct *target,
 403                      const struct user_regset *regset,
 404                      struct membuf to)
 405 {
 406         struct pt_regs *regs = task_regs(target);
 407
 408         return membuf_write(&to, regs->fr, ELF_NFPREG * sizeof(__u64));
 409 }
 410
 411 static int fpr_set(struct task_struct *target,
 412                      const struct user_regset *regset,
 413                      unsigned int pos, unsigned int count,
 414                      const void *kbuf, const void __user *ubuf)
 415 {
 416         struct pt_regs *regs = task_regs(target);
 417         const __u64 *k = kbuf;
 418         const __u64 __user *u = ubuf;
 419         __u64 reg;
 420
 421         pos /= sizeof(reg);
 422         count /= sizeof(reg);
 423
 424         if (kbuf)
 425                 for (; count > 0 && pos < ELF_NFPREG; --count)
 426                         regs->fr[pos++] = *k++;
 427         else
 428                 for (; count > 0 && pos < ELF_NFPREG; --count) {
 429                         if (__get_user(reg, u++))
 430                                 return -EFAULT;
 431                         regs->fr[pos++] = reg;
 432                 }
 433
 434         kbuf = k;
 435         ubuf = u;
 436         pos *= sizeof(reg);
 437         count *= sizeof(reg);
 438         user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 439                                   ELF_NFPREG * sizeof(reg), -1);
 440         return 0;
 441 }
 442
 443 #define RI(reg) (offsetof(struct user_regs_struct,reg) / sizeof(long))
 444
 445 static unsigned long get_reg(struct pt_regs *regs, int num)
 446 {
 447         switch (num) {
 448         case RI(gr[0]) ... RI(gr[31]):  return regs->gr[num - RI(gr[0])];
 449         case RI(sr[0]) ... RI(sr[7]):   return regs->sr[num - RI(sr[0])];
 450         case RI(iasq[0]):               return regs->iasq[0];
 451         case RI(iasq[1]):               return regs->iasq[1];
 452         case RI(iaoq[0]):               return regs->iaoq[0];
 453         case RI(iaoq[1]):               return regs->iaoq[1];
 454         case RI(sar):                   return regs->sar;
 455         case RI(iir):                   return regs->iir;
 456         case RI(isr):                   return regs->isr;
 457         case RI(ior):                   return regs->ior;
 458         case RI(ipsw):                  return regs->ipsw;
 459         case RI(cr27):                  return regs->cr27;
 460         case RI(cr0):                   return mfctl(0);
 461         case RI(cr24):                  return mfctl(24);
 462         case RI(cr25):                  return mfctl(25);
 463         case RI(cr26):                  return mfctl(26);
 464         case RI(cr28):                  return mfctl(28);
 465         case RI(cr29):                  return mfctl(29);
 466         case RI(cr30):                  return mfctl(30);
 467         case RI(cr31):                  return mfctl(31);
 468         case RI(cr8):                   return mfctl(8);
 469         case RI(cr9):                   return mfctl(9);
 470         case RI(cr12):                  return mfctl(12);
 471         case RI(cr13):                  return mfctl(13);
 472         case RI(cr10):                  return mfctl(10);
 473         case RI(cr15):                  return mfctl(15);
 474         default:                        return 0;
 475         }
 476 }
 477
 478 static void set_reg(struct pt_regs *regs, int num, unsigned long val)
 479 {
 480         switch (num) {
 481         case RI(gr[0]): /*
 482                          * PSW is in gr[0].
 483                          * Allow writing to Nullify, Divide-step-correction,
 484                          * and carry/borrow bits.
 485                          * BEWARE, if you set N, and then single step, it won't
 486                          * stop on the nullified instruction.
 487                          */
 488                         val &= USER_PSW_BITS;
 489                         regs->gr[0] &= ~USER_PSW_BITS;
 490                         regs->gr[0] |= val;
 491                         return;
 492         case RI(gr[1]) ... RI(gr[31]):
 493                         regs->gr[num - RI(gr[0])] = val;
 494                         return;
 495         case RI(iaoq[0]):
 496         case RI(iaoq[1]):
 497                         /* set 2 lowest bits to ensure userspace privilege: */
 498                         regs->iaoq[num - RI(iaoq[0])] = val | PRIV_USER;
 499                         return;
 500         case RI(sar):   regs->sar = val;
 501                         return;
 502         default:        return;
 503 #if 0
 504         /* do not allow to change any of the following registers (yet) */
 505         case RI(sr[0]) ... RI(sr[7]):   return regs->sr[num - RI(sr[0])];
 506         case RI(iasq[0]):               return regs->iasq[0];
 507         case RI(iasq[1]):               return regs->iasq[1];
 508         case RI(iir):                   return regs->iir;
 509         case RI(isr):                   return regs->isr;
 510         case RI(ior):                   return regs->ior;
 511         case RI(ipsw):                  return regs->ipsw;
 512         case RI(cr27):                  return regs->cr27;
 513         case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31;
 514         case cr8, cr9, cr12, cr13, cr10, cr15;
 515 #endif
 516         }
 517 }
 518
 519 static int gpr_get(struct task_struct *target,
 520                      const struct user_regset *regset,
 521                      struct membuf to)
 522 {
 523         struct pt_regs *regs = task_regs(target);
 524         unsigned int pos;
 525
 526         for (pos = 0; pos < ELF_NGREG; pos++)
 527                 membuf_store(&to, get_reg(regs, pos));
 528         return 0;
 529 }
 530
 531 static int gpr_set(struct task_struct *target,
 532                      const struct user_regset *regset,
 533                      unsigned int pos, unsigned int count,
 534                      const void *kbuf, const void __user *ubuf)
 535 {
 536         struct pt_regs *regs = task_regs(target);
 537         const unsigned long *k = kbuf;
 538         const unsigned long __user *u = ubuf;
 539         unsigned long reg;
 540
 541         pos /= sizeof(reg);
 542         count /= sizeof(reg);
 543
 544         if (kbuf)
 545                 for (; count > 0 && pos < ELF_NGREG; --count)
 546                         set_reg(regs, pos++, *k++);
 547         else
 548                 for (; count > 0 && pos < ELF_NGREG; --count) {
 549                         if (__get_user(reg, u++))
 550                                 return -EFAULT;
 551                         set_reg(regs, pos++, reg);
 552                 }
 553
 554         kbuf = k;
 555         ubuf = u;
 556         pos *= sizeof(reg);
 557         count *= sizeof(reg);
 558         user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 559                                   ELF_NGREG * sizeof(reg), -1);
 560         return 0;
 561 }
 562
 563 static const struct user_regset native_regsets[] = {
 564         [REGSET_GENERAL] = {
 565                 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
 566                 .size = sizeof(long), .align = sizeof(long),
 567                 .regset_get = gpr_get, .set = gpr_set
 568         },
 569         [REGSET_FP] = {
 570                 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
 571                 .size = sizeof(__u64), .align = sizeof(__u64),
 572                 .regset_get = fpr_get, .set = fpr_set
 573         }
 574 };
 575
 576 static const struct user_regset_view user_parisc_native_view = {
 577         .name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX,
 578         .regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
 579 };
 580
 581 #ifdef CONFIG_64BIT
 582 static int gpr32_get(struct task_struct *target,
 583                      const struct user_regset *regset,
 584                      struct membuf to)
 585 {
 586         struct pt_regs *regs = task_regs(target);
 587         unsigned int pos;
 588
 589         for (pos = 0; pos < ELF_NGREG; pos++)
 590                 membuf_store(&to, (compat_ulong_t)get_reg(regs, pos));
 591
 592         return 0;
 593 }
 594
 595 static int gpr32_set(struct task_struct *target,
 596                      const struct user_regset *regset,
 597                      unsigned int pos, unsigned int count,
 598                      const void *kbuf, const void __user *ubuf)
 599 {
 600         struct pt_regs *regs = task_regs(target);
 601         const compat_ulong_t *k = kbuf;
 602         const compat_ulong_t __user *u = ubuf;
 603         compat_ulong_t reg;
 604
 605         pos /= sizeof(reg);
 606         count /= sizeof(reg);
 607
 608         if (kbuf)
 609                 for (; count > 0 && pos < ELF_NGREG; --count)
 610                         set_reg(regs, pos++, *k++);
 611         else
 612                 for (; count > 0 && pos < ELF_NGREG; --count) {
 613                         if (__get_user(reg, u++))
 614                                 return -EFAULT;
 615                         set_reg(regs, pos++, reg);
 616                 }
 617
 618         kbuf = k;
 619         ubuf = u;
 620         pos *= sizeof(reg);
 621         count *= sizeof(reg);
 622         user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 623                                   ELF_NGREG * sizeof(reg), -1);
 624         return 0;
 625 }
 626
 627 /*
 628  * These are the regset flavors matching the 32bit native set.
 629  */
 630 static const struct user_regset compat_regsets[] = {
 631         [REGSET_GENERAL] = {
 632                 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
 633                 .size = sizeof(compat_long_t), .align = sizeof(compat_long_t),
 634                 .regset_get = gpr32_get, .set = gpr32_set
 635         },
 636         [REGSET_FP] = {
 637                 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
 638                 .size = sizeof(__u64), .align = sizeof(__u64),
 639                 .regset_get = fpr_get, .set = fpr_set
 640         }
 641 };
 642
 643 static const struct user_regset_view user_parisc_compat_view = {
 644         .name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX,
 645         .regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
 646 };
 647 #endif  /* CONFIG_64BIT */
 648
 649 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 650 {
 651         BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG);
 652         BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG);
 653 #ifdef CONFIG_64BIT
 654         if (is_compat_task())
 655                 return &user_parisc_compat_view;
 656 #endif
 657         return &user_parisc_native_view;
 658 }
 659
 660
 661 /* HAVE_REGS_AND_STACK_ACCESS_API feature */
 662
 663 struct pt_regs_offset {
 664         const char *name;
 665         int offset;
 666 };
 667
 668 #define REG_OFFSET_NAME(r)    {.name = #r, .offset = offsetof(struct pt_regs, r)}
 669 #define REG_OFFSET_INDEX(r,i) {.name = #r#i, .offset = offsetof(struct pt_regs, r[i])}
 670 #define REG_OFFSET_END {.name = NULL, .offset = 0}
 671
 672 static const struct pt_regs_offset regoffset_table[] = {
 673         REG_OFFSET_INDEX(gr,0),
 674         REG_OFFSET_INDEX(gr,1),
 675         REG_OFFSET_INDEX(gr,2),
 676         REG_OFFSET_INDEX(gr,3),
 677         REG_OFFSET_INDEX(gr,4),
 678         REG_OFFSET_INDEX(gr,5),
 679         REG_OFFSET_INDEX(gr,6),
 680         REG_OFFSET_INDEX(gr,7),
 681         REG_OFFSET_INDEX(gr,8),
 682         REG_OFFSET_INDEX(gr,9),
 683         REG_OFFSET_INDEX(gr,10),
 684         REG_OFFSET_INDEX(gr,11),
 685         REG_OFFSET_INDEX(gr,12),
 686         REG_OFFSET_INDEX(gr,13),
 687         REG_OFFSET_INDEX(gr,14),
 688         REG_OFFSET_INDEX(gr,15),
 689         REG_OFFSET_INDEX(gr,16),
 690         REG_OFFSET_INDEX(gr,17),
 691         REG_OFFSET_INDEX(gr,18),
 692         REG_OFFSET_INDEX(gr,19),
 693         REG_OFFSET_INDEX(gr,20),
 694         REG_OFFSET_INDEX(gr,21),
 695         REG_OFFSET_INDEX(gr,22),
 696         REG_OFFSET_INDEX(gr,23),
 697         REG_OFFSET_INDEX(gr,24),
 698         REG_OFFSET_INDEX(gr,25),
 699         REG_OFFSET_INDEX(gr,26),
 700         REG_OFFSET_INDEX(gr,27),
 701         REG_OFFSET_INDEX(gr,28),
 702         REG_OFFSET_INDEX(gr,29),
 703         REG_OFFSET_INDEX(gr,30),
 704         REG_OFFSET_INDEX(gr,31),
 705         REG_OFFSET_INDEX(sr,0),
 706         REG_OFFSET_INDEX(sr,1),
 707         REG_OFFSET_INDEX(sr,2),
 708         REG_OFFSET_INDEX(sr,3),
 709         REG_OFFSET_INDEX(sr,4),
 710         REG_OFFSET_INDEX(sr,5),
 711         REG_OFFSET_INDEX(sr,6),
 712         REG_OFFSET_INDEX(sr,7),
 713         REG_OFFSET_INDEX(iasq,0),
 714         REG_OFFSET_INDEX(iasq,1),
 715         REG_OFFSET_INDEX(iaoq,0),
 716         REG_OFFSET_INDEX(iaoq,1),
 717         REG_OFFSET_NAME(cr27),
 718         REG_OFFSET_NAME(ksp),
 719         REG_OFFSET_NAME(kpc),
 720         REG_OFFSET_NAME(sar),
 721         REG_OFFSET_NAME(iir),
 722         REG_OFFSET_NAME(isr),
 723         REG_OFFSET_NAME(ior),
 724         REG_OFFSET_NAME(ipsw),
 725         REG_OFFSET_END,
 726 };
 727
 728 /**
 729  * regs_query_register_offset() - query register offset from its name
 730  * @name:       the name of a register
 731  *
 732  * regs_query_register_offset() returns the offset of a register in struct
 733  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 734  */
 735 int regs_query_register_offset(const char *name)
 736 {
 737         const struct pt_regs_offset *roff;
 738         for (roff = regoffset_table; roff->name != NULL; roff++)
 739                 if (!strcmp(roff->name, name))
 740                         return roff->offset;
 741         return -EINVAL;
 742 }
 743
 744 /**
 745  * regs_query_register_name() - query register name from its offset
 746  * @offset:     the offset of a register in struct pt_regs.
 747  *
 748  * regs_query_register_name() returns the name of a register from its
 749  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 750  */
 751 const char *regs_query_register_name(unsigned int offset)
 752 {
 753         const struct pt_regs_offset *roff;
 754         for (roff = regoffset_table; roff->name != NULL; roff++)
 755                 if (roff->offset == offset)
 756                         return roff->name;
 757         return NULL;
 758 }
 759
 760 /**
 761  * regs_within_kernel_stack() - check the address in the stack
 762  * @regs:      pt_regs which contains kernel stack pointer.
 763  * @addr:      address which is checked.
 764  *
 765  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 766  * If @addr is within the kernel stack, it returns true. If not, returns false.
 767  */
 768 int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 769 {
 770         return ((addr & ~(THREAD_SIZE - 1))  ==
 771                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
 772 }
 773
 774 /**
 775  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 776  * @regs:       pt_regs which contains kernel stack pointer.
 777  * @n:          stack entry number.
 778  *
 779  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 780  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 781  * this returns 0.
 782  */
 783 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 784 {
 785         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 786
 787         addr -= n;
 788
 789         if (!regs_within_kernel_stack(regs, (unsigned long)addr))
 790                 return 0;
 791
 792         return *addr;
 793 }