arch/mips/kernel/ptrace.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1992 Ross Biro
   7  * Copyright (C) Linus Torvalds
   8  * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
   9  * Copyright (C) 1996 David S. Miller
  10  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
  11  * Copyright (C) 1999 MIPS Technologies, Inc.
  12  * Copyright (C) 2000 Ulf Carlsson
  13  *
  14  * At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit
  15  * binaries.
  16  */
  17 #include <linux/compiler.h>
  18 #include <linux/context_tracking.h>
  19 #include <linux/elf.h>
  20 #include <linux/kernel.h>
  21 #include <linux/sched.h>
  22 #include <linux/sched/task_stack.h>
  23 #include <linux/mm.h>
  24 #include <linux/errno.h>
  25 #include <linux/ptrace.h>
  26 #include <linux/regset.h>
  27 #include <linux/smp.h>
  28 #include <linux/security.h>
  29 #include <linux/stddef.h>
  30 #include <linux/tracehook.h>
  31 #include <linux/audit.h>
  32 #include <linux/seccomp.h>
  33 #include <linux/ftrace.h>
  34
  35 #include <asm/byteorder.h>
  36 #include <asm/cpu.h>
  37 #include <asm/cpu-info.h>
  38 #include <asm/dsp.h>
  39 #include <asm/fpu.h>
  40 #include <asm/mipsregs.h>
  41 #include <asm/mipsmtregs.h>
  42 #include <asm/pgtable.h>
  43 #include <asm/page.h>
  44 #include <asm/processor.h>
  45 #include <asm/syscall.h>
  46 #include <linux/uaccess.h>
  47 #include <asm/bootinfo.h>
  48 #include <asm/reg.h>
  49
  50 #define CREATE_TRACE_POINTS
  51 #include <trace/events/syscalls.h>
  52
  53 static void init_fp_ctx(struct task_struct *target)
  54 {
  55         /* If FP has been used then the target already has context */
  56         if (tsk_used_math(target))
  57                 return;
  58
  59         /* Begin with data registers set to all 1s... */
  60         memset(&target->thread.fpu.fpr, ~0, sizeof(target->thread.fpu.fpr));
  61
  62         /* FCSR has been preset by `mips_set_personality_nan'.  */
  63
  64         /*
  65          * Record that the target has "used" math, such that the context
  66          * just initialised, and any modifications made by the caller,
  67          * aren't discarded.
  68          */
  69         set_stopped_child_used_math(target);
  70 }
  71
  72 /*
  73  * Called by kernel/ptrace.c when detaching..
  74  *
  75  * Make sure single step bits etc are not set.
  76  */
  77 void ptrace_disable(struct task_struct *child)
  78 {
  79         /* Don't load the watchpoint registers for the ex-child. */
  80         clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
  81 }
  82
  83 /*
  84  * Poke at FCSR according to its mask.  Set the Cause bits even
  85  * if a corresponding Enable bit is set.  This will be noticed at
  86  * the time the thread is switched to and SIGFPE thrown accordingly.
  87  */
  88 static void ptrace_setfcr31(struct task_struct *child, u32 value)
  89 {
  90         u32 fcr31;
  91         u32 mask;
  92
  93         fcr31 = child->thread.fpu.fcr31;
  94         mask = boot_cpu_data.fpu_msk31;
  95         child->thread.fpu.fcr31 = (value & ~mask) | (fcr31 & mask);
  96 }
  97
  98 /*
  99  * Read a general register set.  We always use the 64-bit format, even
 100  * for 32-bit kernels and for 32-bit processes on a 64-bit kernel.
 101  * Registers are sign extended to fill the available space.
 102  */
 103 int ptrace_getregs(struct task_struct *child, struct user_pt_regs __user *data)
 104 {
 105         struct pt_regs *regs;
 106         int i;
 107
 108         if (!access_ok(VERIFY_WRITE, data, 38 * 8))
 109                 return -EIO;
 110
 111         regs = task_pt_regs(child);
 112
 113         for (i = 0; i < 32; i++)
 114                 __put_user((long)regs->regs[i], (__s64 __user *)&data->regs[i]);
 115         __put_user((long)regs->lo, (__s64 __user *)&data->lo);
 116         __put_user((long)regs->hi, (__s64 __user *)&data->hi);
 117         __put_user((long)regs->cp0_epc, (__s64 __user *)&data->cp0_epc);
 118         __put_user((long)regs->cp0_badvaddr, (__s64 __user *)&data->cp0_badvaddr);
 119         __put_user((long)regs->cp0_status, (__s64 __user *)&data->cp0_status);
 120         __put_user((long)regs->cp0_cause, (__s64 __user *)&data->cp0_cause);
 121
 122         return 0;
 123 }
 124
 125 /*
 126  * Write a general register set.  As for PTRACE_GETREGS, we always use
 127  * the 64-bit format.  On a 32-bit kernel only the lower order half
 128  * (according to endianness) will be used.
 129  */
 130 int ptrace_setregs(struct task_struct *child, struct user_pt_regs __user *data)
 131 {
 132         struct pt_regs *regs;
 133         int i;
 134
 135         if (!access_ok(VERIFY_READ, data, 38 * 8))
 136                 return -EIO;
 137
 138         regs = task_pt_regs(child);
 139
 140         for (i = 0; i < 32; i++)
 141                 __get_user(regs->regs[i], (__s64 __user *)&data->regs[i]);
 142         __get_user(regs->lo, (__s64 __user *)&data->lo);
 143         __get_user(regs->hi, (__s64 __user *)&data->hi);
 144         __get_user(regs->cp0_epc, (__s64 __user *)&data->cp0_epc);
 145
 146         /* badvaddr, status, and cause may not be written.  */
 147
 148         /* System call number may have been changed */
 149         mips_syscall_update_nr(child, regs);
 150
 151         return 0;
 152 }
 153
 154 int ptrace_getfpregs(struct task_struct *child, __u32 __user *data)
 155 {
 156         int i;
 157
 158         if (!access_ok(VERIFY_WRITE, data, 33 * 8))
 159                 return -EIO;
 160
 161         if (tsk_used_math(child)) {
 162                 union fpureg *fregs = get_fpu_regs(child);
 163                 for (i = 0; i < 32; i++)
 164                         __put_user(get_fpr64(&fregs[i], 0),
 165                                    i + (__u64 __user *)data);
 166         } else {
 167                 for (i = 0; i < 32; i++)
 168                         __put_user((__u64) -1, i + (__u64 __user *) data);
 169         }
 170
 171         __put_user(child->thread.fpu.fcr31, data + 64);
 172         __put_user(boot_cpu_data.fpu_id, data + 65);
 173
 174         return 0;
 175 }
 176
 177 int ptrace_setfpregs(struct task_struct *child, __u32 __user *data)
 178 {
 179         union fpureg *fregs;
 180         u64 fpr_val;
 181         u32 value;
 182         int i;
 183
 184         if (!access_ok(VERIFY_READ, data, 33 * 8))
 185                 return -EIO;
 186
 187         init_fp_ctx(child);
 188         fregs = get_fpu_regs(child);
 189
 190         for (i = 0; i < 32; i++) {
 191                 __get_user(fpr_val, i + (__u64 __user *)data);
 192                 set_fpr64(&fregs[i], 0, fpr_val);
 193         }
 194
 195         __get_user(value, data + 64);
 196         ptrace_setfcr31(child, value);
 197
 198         /* FIR may not be written.  */
 199
 200         return 0;
 201 }
 202
 203 int ptrace_get_watch_regs(struct task_struct *child,
 204                           struct pt_watch_regs __user *addr)
 205 {
 206         enum pt_watch_style style;
 207         int i;
 208
 209         if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
 210                 return -EIO;
 211         if (!access_ok(VERIFY_WRITE, addr, sizeof(struct pt_watch_regs)))
 212                 return -EIO;
 213
 214 #ifdef CONFIG_32BIT
 215         style = pt_watch_style_mips32;
 216 #define WATCH_STYLE mips32
 217 #else
 218         style = pt_watch_style_mips64;
 219 #define WATCH_STYLE mips64
 220 #endif
 221
 222         __put_user(style, &addr->style);
 223         __put_user(boot_cpu_data.watch_reg_use_cnt,
 224                    &addr->WATCH_STYLE.num_valid);
 225         for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
 226                 __put_user(child->thread.watch.mips3264.watchlo[i],
 227                            &addr->WATCH_STYLE.watchlo[i]);
 228                 __put_user(child->thread.watch.mips3264.watchhi[i] &
 229                                 (MIPS_WATCHHI_MASK | MIPS_WATCHHI_IRW),
 230                            &addr->WATCH_STYLE.watchhi[i]);
 231                 __put_user(boot_cpu_data.watch_reg_masks[i],
 232                            &addr->WATCH_STYLE.watch_masks[i]);
 233         }
 234         for (; i < 8; i++) {
 235                 __put_user(0, &addr->WATCH_STYLE.watchlo[i]);
 236                 __put_user(0, &addr->WATCH_STYLE.watchhi[i]);
 237                 __put_user(0, &addr->WATCH_STYLE.watch_masks[i]);
 238         }
 239
 240         return 0;
 241 }
 242
 243 int ptrace_set_watch_regs(struct task_struct *child,
 244                           struct pt_watch_regs __user *addr)
 245 {
 246         int i;
 247         int watch_active = 0;
 248         unsigned long lt[NUM_WATCH_REGS];
 249         u16 ht[NUM_WATCH_REGS];
 250
 251         if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
 252                 return -EIO;
 253         if (!access_ok(VERIFY_READ, addr, sizeof(struct pt_watch_regs)))
 254                 return -EIO;
 255         /* Check the values. */
 256         for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
 257                 __get_user(lt[i], &addr->WATCH_STYLE.watchlo[i]);
 258 #ifdef CONFIG_32BIT
 259                 if (lt[i] & __UA_LIMIT)
 260                         return -EINVAL;
 261 #else
 262                 if (test_tsk_thread_flag(child, TIF_32BIT_ADDR)) {
 263                         if (lt[i] & 0xffffffff80000000UL)
 264                                 return -EINVAL;
 265                 } else {
 266                         if (lt[i] & __UA_LIMIT)
 267                                 return -EINVAL;
 268                 }
 269 #endif
 270                 __get_user(ht[i], &addr->WATCH_STYLE.watchhi[i]);
 271                 if (ht[i] & ~MIPS_WATCHHI_MASK)
 272                         return -EINVAL;
 273         }
 274         /* Install them. */
 275         for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
 276                 if (lt[i] & MIPS_WATCHLO_IRW)
 277                         watch_active = 1;
 278                 child->thread.watch.mips3264.watchlo[i] = lt[i];
 279                 /* Set the G bit. */
 280                 child->thread.watch.mips3264.watchhi[i] = ht[i];
 281         }
 282
 283         if (watch_active)
 284                 set_tsk_thread_flag(child, TIF_LOAD_WATCH);
 285         else
 286                 clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
 287
 288         return 0;
 289 }
 290
 291 /* regset get/set implementations */
 292
 293 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
 294
 295 static int gpr32_get(struct task_struct *target,
 296                      const struct user_regset *regset,
 297                      unsigned int pos, unsigned int count,
 298                      void *kbuf, void __user *ubuf)
 299 {
 300         struct pt_regs *regs = task_pt_regs(target);
 301         u32 uregs[ELF_NGREG] = {};
 302
 303         mips_dump_regs32(uregs, regs);
 304         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
 305                                    sizeof(uregs));
 306 }
 307
 308 static int gpr32_set(struct task_struct *target,
 309                      const struct user_regset *regset,
 310                      unsigned int pos, unsigned int count,
 311                      const void *kbuf, const void __user *ubuf)
 312 {
 313         struct pt_regs *regs = task_pt_regs(target);
 314         u32 uregs[ELF_NGREG];
 315         unsigned start, num_regs, i;
 316         int err;
 317
 318         start = pos / sizeof(u32);
 319         num_regs = count / sizeof(u32);
 320
 321         if (start + num_regs > ELF_NGREG)
 322                 return -EIO;
 323
 324         err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
 325                                  sizeof(uregs));
 326         if (err)
 327                 return err;
 328
 329         for (i = start; i < num_regs; i++) {
 330                 /*
 331                  * Cast all values to signed here so that if this is a 64-bit
 332                  * kernel, the supplied 32-bit values will be sign extended.
 333                  */
 334                 switch (i) {
 335                 case MIPS32_EF_R1 ... MIPS32_EF_R25:
 336                         /* k0/k1 are ignored. */
 337                 case MIPS32_EF_R28 ... MIPS32_EF_R31:
 338                         regs->regs[i - MIPS32_EF_R0] = (s32)uregs[i];
 339                         break;
 340                 case MIPS32_EF_LO:
 341                         regs->lo = (s32)uregs[i];
 342                         break;
 343                 case MIPS32_EF_HI:
 344                         regs->hi = (s32)uregs[i];
 345                         break;
 346                 case MIPS32_EF_CP0_EPC:
 347                         regs->cp0_epc = (s32)uregs[i];
 348                         break;
 349                 }
 350         }
 351
 352         /* System call number may have been changed */
 353         mips_syscall_update_nr(target, regs);
 354
 355         return 0;
 356 }
 357
 358 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
 359
 360 #ifdef CONFIG_64BIT
 361
 362 static int gpr64_get(struct task_struct *target,
 363                      const struct user_regset *regset,
 364                      unsigned int pos, unsigned int count,
 365                      void *kbuf, void __user *ubuf)
 366 {
 367         struct pt_regs *regs = task_pt_regs(target);
 368         u64 uregs[ELF_NGREG] = {};
 369
 370         mips_dump_regs64(uregs, regs);
 371         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
 372                                    sizeof(uregs));
 373 }
 374
 375 static int gpr64_set(struct task_struct *target,
 376                      const struct user_regset *regset,
 377                      unsigned int pos, unsigned int count,
 378                      const void *kbuf, const void __user *ubuf)
 379 {
 380         struct pt_regs *regs = task_pt_regs(target);
 381         u64 uregs[ELF_NGREG];
 382         unsigned start, num_regs, i;
 383         int err;
 384
 385         start = pos / sizeof(u64);
 386         num_regs = count / sizeof(u64);
 387
 388         if (start + num_regs > ELF_NGREG)
 389                 return -EIO;
 390
 391         err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
 392                                  sizeof(uregs));
 393         if (err)
 394                 return err;
 395
 396         for (i = start; i < num_regs; i++) {
 397                 switch (i) {
 398                 case MIPS64_EF_R1 ... MIPS64_EF_R25:
 399                         /* k0/k1 are ignored. */
 400                 case MIPS64_EF_R28 ... MIPS64_EF_R31:
 401                         regs->regs[i - MIPS64_EF_R0] = uregs[i];
 402                         break;
 403                 case MIPS64_EF_LO:
 404                         regs->lo = uregs[i];
 405                         break;
 406                 case MIPS64_EF_HI:
 407                         regs->hi = uregs[i];
 408                         break;
 409                 case MIPS64_EF_CP0_EPC:
 410                         regs->cp0_epc = uregs[i];
 411                         break;
 412                 }
 413         }
 414
 415         /* System call number may have been changed */
 416         mips_syscall_update_nr(target, regs);
 417
 418         return 0;
 419 }
 420
 421 #endif /* CONFIG_64BIT */
 422
 423 /*
 424  * Copy the floating-point context to the supplied NT_PRFPREG buffer,
 425  * !CONFIG_CPU_HAS_MSA variant.  FP context's general register slots
 426  * correspond 1:1 to buffer slots.  Only general registers are copied.
 427  */
 428 static int fpr_get_fpa(struct task_struct *target,
 429                        unsigned int *pos, unsigned int *count,
 430                        void **kbuf, void __user **ubuf)
 431 {
 432         return user_regset_copyout(pos, count, kbuf, ubuf,
 433                                    &target->thread.fpu,
 434                                    0, NUM_FPU_REGS * sizeof(elf_fpreg_t));
 435 }
 436
 437 /*
 438  * Copy the floating-point context to the supplied NT_PRFPREG buffer,
 439  * CONFIG_CPU_HAS_MSA variant.  Only lower 64 bits of FP context's
 440  * general register slots are copied to buffer slots.  Only general
 441  * registers are copied.
 442  */
 443 static int fpr_get_msa(struct task_struct *target,
 444                        unsigned int *pos, unsigned int *count,
 445                        void **kbuf, void __user **ubuf)
 446 {
 447         unsigned int i;
 448         u64 fpr_val;
 449         int err;
 450
 451         BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
 452         for (i = 0; i < NUM_FPU_REGS; i++) {
 453                 fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
 454                 err = user_regset_copyout(pos, count, kbuf, ubuf,
 455                                           &fpr_val, i * sizeof(elf_fpreg_t),
 456                                           (i + 1) * sizeof(elf_fpreg_t));
 457                 if (err)
 458                         return err;
 459         }
 460
 461         return 0;
 462 }
 463
 464 /*
 465  * Copy the floating-point context to the supplied NT_PRFPREG buffer.
 466  * Choose the appropriate helper for general registers, and then copy
 467  * the FCSR and FIR registers separately.
 468  */
 469 static int fpr_get(struct task_struct *target,
 470                    const struct user_regset *regset,
 471                    unsigned int pos, unsigned int count,
 472                    void *kbuf, void __user *ubuf)
 473 {
 474         const int fcr31_pos = NUM_FPU_REGS * sizeof(elf_fpreg_t);
 475         const int fir_pos = fcr31_pos + sizeof(u32);
 476         int err;
 477
 478         if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
 479                 err = fpr_get_fpa(target, &pos, &count, &kbuf, &ubuf);
 480         else
 481                 err = fpr_get_msa(target, &pos, &count, &kbuf, &ubuf);
 482         if (err)
 483                 return err;
 484
 485         err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 486                                   &target->thread.fpu.fcr31,
 487                                   fcr31_pos, fcr31_pos + sizeof(u32));
 488         if (err)
 489                 return err;
 490
 491         err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 492                                   &boot_cpu_data.fpu_id,
 493                                   fir_pos, fir_pos + sizeof(u32));
 494
 495         return err;
 496 }
 497
 498 /*
 499  * Copy the supplied NT_PRFPREG buffer to the floating-point context,
 500  * !CONFIG_CPU_HAS_MSA variant.   Buffer slots correspond 1:1 to FP
 501  * context's general register slots.  Only general registers are copied.
 502  */
 503 static int fpr_set_fpa(struct task_struct *target,
 504                        unsigned int *pos, unsigned int *count,
 505                        const void **kbuf, const void __user **ubuf)
 506 {
 507         return user_regset_copyin(pos, count, kbuf, ubuf,
 508                                   &target->thread.fpu,
 509                                   0, NUM_FPU_REGS * sizeof(elf_fpreg_t));
 510 }
 511
 512 /*
 513  * Copy the supplied NT_PRFPREG buffer to the floating-point context,
 514  * CONFIG_CPU_HAS_MSA variant.  Buffer slots are copied to lower 64
 515  * bits only of FP context's general register slots.  Only general
 516  * registers are copied.
 517  */
 518 static int fpr_set_msa(struct task_struct *target,
 519                        unsigned int *pos, unsigned int *count,
 520                        const void **kbuf, const void __user **ubuf)
 521 {
 522         unsigned int i;
 523         u64 fpr_val;
 524         int err;
 525
 526         BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
 527         for (i = 0; i < NUM_FPU_REGS && *count > 0; i++) {
 528                 err = user_regset_copyin(pos, count, kbuf, ubuf,
 529                                          &fpr_val, i * sizeof(elf_fpreg_t),
 530                                          (i + 1) * sizeof(elf_fpreg_t));
 531                 if (err)
 532                         return err;
 533                 set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
 534         }
 535
 536         return 0;
 537 }
 538
 539 /*
 540  * Copy the supplied NT_PRFPREG buffer to the floating-point context.
 541  * Choose the appropriate helper for general registers, and then copy
 542  * the FCSR register separately.  Ignore the incoming FIR register
 543  * contents though, as the register is read-only.
 544  *
 545  * We optimize for the case where `count % sizeof(elf_fpreg_t) == 0',
 546  * which is supposed to have been guaranteed by the kernel before
 547  * calling us, e.g. in `ptrace_regset'.  We enforce that requirement,
 548  * so that we can safely avoid preinitializing temporaries for
 549  * partial register writes.
 550  */
 551 static int fpr_set(struct task_struct *target,
 552                    const struct user_regset *regset,
 553                    unsigned int pos, unsigned int count,
 554                    const void *kbuf, const void __user *ubuf)
 555 {
 556         const int fcr31_pos = NUM_FPU_REGS * sizeof(elf_fpreg_t);
 557         const int fir_pos = fcr31_pos + sizeof(u32);
 558         u32 fcr31;
 559         int err;
 560
 561         BUG_ON(count % sizeof(elf_fpreg_t));
 562
 563         if (pos + count > sizeof(elf_fpregset_t))
 564                 return -EIO;
 565
 566         init_fp_ctx(target);
 567
 568         if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
 569                 err = fpr_set_fpa(target, &pos, &count, &kbuf, &ubuf);
 570         else
 571                 err = fpr_set_msa(target, &pos, &count, &kbuf, &ubuf);
 572         if (err)
 573                 return err;
 574
 575         if (count > 0) {
 576                 err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 577                                          &fcr31,
 578                                          fcr31_pos, fcr31_pos + sizeof(u32));
 579                 if (err)
 580                         return err;
 581
 582                 ptrace_setfcr31(target, fcr31);
 583         }
 584
 585         if (count > 0)
 586                 err = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 587                                                 fir_pos,
 588                                                 fir_pos + sizeof(u32));
 589
 590         return err;
 591 }
 592
 593 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
 594
 595 /*
 596  * Copy the DSP context to the supplied 32-bit NT_MIPS_DSP buffer.
 597  */
 598 static int dsp32_get(struct task_struct *target,
 599                      const struct user_regset *regset,
 600                      unsigned int pos, unsigned int count,
 601                      void *kbuf, void __user *ubuf)
 602 {
 603         unsigned int start, num_regs, i;
 604         u32 dspregs[NUM_DSP_REGS + 1];
 605
 606         BUG_ON(count % sizeof(u32));
 607
 608         if (!cpu_has_dsp)
 609                 return -EIO;
 610
 611         start = pos / sizeof(u32);
 612         num_regs = count / sizeof(u32);
 613
 614         if (start + num_regs > NUM_DSP_REGS + 1)
 615                 return -EIO;
 616
 617         for (i = start; i < num_regs; i++)
 618                 switch (i) {
 619                 case 0 ... NUM_DSP_REGS - 1:
 620                         dspregs[i] = target->thread.dsp.dspr[i];
 621                         break;
 622                 case NUM_DSP_REGS:
 623                         dspregs[i] = target->thread.dsp.dspcontrol;
 624                         break;
 625                 }
 626         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, dspregs, 0,
 627                                    sizeof(dspregs));
 628 }
 629
 630 /*
 631  * Copy the supplied 32-bit NT_MIPS_DSP buffer to the DSP context.
 632  */
 633 static int dsp32_set(struct task_struct *target,
 634                      const struct user_regset *regset,
 635                      unsigned int pos, unsigned int count,
 636                      const void *kbuf, const void __user *ubuf)
 637 {
 638         unsigned int start, num_regs, i;
 639         u32 dspregs[NUM_DSP_REGS + 1];
 640         int err;
 641
 642         BUG_ON(count % sizeof(u32));
 643
 644         if (!cpu_has_dsp)
 645                 return -EIO;
 646
 647         start = pos / sizeof(u32);
 648         num_regs = count / sizeof(u32);
 649
 650         if (start + num_regs > NUM_DSP_REGS + 1)
 651                 return -EIO;
 652
 653         err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, dspregs, 0,
 654                                  sizeof(dspregs));
 655         if (err)
 656                 return err;
 657
 658         for (i = start; i < num_regs; i++)
 659                 switch (i) {
 660                 case 0 ... NUM_DSP_REGS - 1:
 661                         target->thread.dsp.dspr[i] = (s32)dspregs[i];
 662                         break;
 663                 case NUM_DSP_REGS:
 664                         target->thread.dsp.dspcontrol = (s32)dspregs[i];
 665                         break;
 666                 }
 667
 668         return 0;
 669 }
 670
 671 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
 672
 673 #ifdef CONFIG_64BIT
 674
 675 /*
 676  * Copy the DSP context to the supplied 64-bit NT_MIPS_DSP buffer.
 677  */
 678 static int dsp64_get(struct task_struct *target,
 679                      const struct user_regset *regset,
 680                      unsigned int pos, unsigned int count,
 681                      void *kbuf, void __user *ubuf)
 682 {
 683         unsigned int start, num_regs, i;
 684         u64 dspregs[NUM_DSP_REGS + 1];
 685
 686         BUG_ON(count % sizeof(u64));
 687
 688         if (!cpu_has_dsp)
 689                 return -EIO;
 690
 691         start = pos / sizeof(u64);
 692         num_regs = count / sizeof(u64);
 693
 694         if (start + num_regs > NUM_DSP_REGS + 1)
 695                 return -EIO;
 696
 697         for (i = start; i < num_regs; i++)
 698                 switch (i) {
 699                 case 0 ... NUM_DSP_REGS - 1:
 700                         dspregs[i] = target->thread.dsp.dspr[i];
 701                         break;
 702                 case NUM_DSP_REGS:
 703                         dspregs[i] = target->thread.dsp.dspcontrol;
 704                         break;
 705                 }
 706         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, dspregs, 0,
 707                                    sizeof(dspregs));
 708 }
 709
 710 /*
 711  * Copy the supplied 64-bit NT_MIPS_DSP buffer to the DSP context.
 712  */
 713 static int dsp64_set(struct task_struct *target,
 714                      const struct user_regset *regset,
 715                      unsigned int pos, unsigned int count,
 716                      const void *kbuf, const void __user *ubuf)
 717 {
 718         unsigned int start, num_regs, i;
 719         u64 dspregs[NUM_DSP_REGS + 1];
 720         int err;
 721
 722         BUG_ON(count % sizeof(u64));
 723
 724         if (!cpu_has_dsp)
 725                 return -EIO;
 726
 727         start = pos / sizeof(u64);
 728         num_regs = count / sizeof(u64);
 729
 730         if (start + num_regs > NUM_DSP_REGS + 1)
 731                 return -EIO;
 732
 733         err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, dspregs, 0,
 734                                  sizeof(dspregs));
 735         if (err)
 736                 return err;
 737
 738         for (i = start; i < num_regs; i++)
 739                 switch (i) {
 740                 case 0 ... NUM_DSP_REGS - 1:
 741                         target->thread.dsp.dspr[i] = dspregs[i];
 742                         break;
 743                 case NUM_DSP_REGS:
 744                         target->thread.dsp.dspcontrol = dspregs[i];
 745                         break;
 746                 }
 747
 748         return 0;
 749 }
 750
 751 #endif /* CONFIG_64BIT */
 752
 753 /*
 754  * Determine whether the DSP context is present.
 755  */
 756 static int dsp_active(struct task_struct *target,
 757                       const struct user_regset *regset)
 758 {
 759         return cpu_has_dsp ? NUM_DSP_REGS + 1 : -ENODEV;
 760 }
 761
 762 enum mips_regset {
 763         REGSET_GPR,
 764         REGSET_FPR,
 765         REGSET_DSP,
 766 };
 767
 768 struct pt_regs_offset {
 769         const char *name;
 770         int offset;
 771 };
 772
 773 #define REG_OFFSET_NAME(reg, r) {                                       \
 774         .name = #reg,                                                   \
 775         .offset = offsetof(struct pt_regs, r)                           \
 776 }
 777
 778 #define REG_OFFSET_END {                                                \
 779         .name = NULL,                                                   \
 780         .offset = 0                                                     \
 781 }
 782
 783 static const struct pt_regs_offset regoffset_table[] = {
 784         REG_OFFSET_NAME(r0, regs[0]),
 785         REG_OFFSET_NAME(r1, regs[1]),
 786         REG_OFFSET_NAME(r2, regs[2]),
 787         REG_OFFSET_NAME(r3, regs[3]),
 788         REG_OFFSET_NAME(r4, regs[4]),
 789         REG_OFFSET_NAME(r5, regs[5]),
 790         REG_OFFSET_NAME(r6, regs[6]),
 791         REG_OFFSET_NAME(r7, regs[7]),
 792         REG_OFFSET_NAME(r8, regs[8]),
 793         REG_OFFSET_NAME(r9, regs[9]),
 794         REG_OFFSET_NAME(r10, regs[10]),
 795         REG_OFFSET_NAME(r11, regs[11]),
 796         REG_OFFSET_NAME(r12, regs[12]),
 797         REG_OFFSET_NAME(r13, regs[13]),
 798         REG_OFFSET_NAME(r14, regs[14]),
 799         REG_OFFSET_NAME(r15, regs[15]),
 800         REG_OFFSET_NAME(r16, regs[16]),
 801         REG_OFFSET_NAME(r17, regs[17]),
 802         REG_OFFSET_NAME(r18, regs[18]),
 803         REG_OFFSET_NAME(r19, regs[19]),
 804         REG_OFFSET_NAME(r20, regs[20]),
 805         REG_OFFSET_NAME(r21, regs[21]),
 806         REG_OFFSET_NAME(r22, regs[22]),
 807         REG_OFFSET_NAME(r23, regs[23]),
 808         REG_OFFSET_NAME(r24, regs[24]),
 809         REG_OFFSET_NAME(r25, regs[25]),
 810         REG_OFFSET_NAME(r26, regs[26]),
 811         REG_OFFSET_NAME(r27, regs[27]),
 812         REG_OFFSET_NAME(r28, regs[28]),
 813         REG_OFFSET_NAME(r29, regs[29]),
 814         REG_OFFSET_NAME(r30, regs[30]),
 815         REG_OFFSET_NAME(r31, regs[31]),
 816         REG_OFFSET_NAME(c0_status, cp0_status),
 817         REG_OFFSET_NAME(hi, hi),
 818         REG_OFFSET_NAME(lo, lo),
 819 #ifdef CONFIG_CPU_HAS_SMARTMIPS
 820         REG_OFFSET_NAME(acx, acx),
 821 #endif
 822         REG_OFFSET_NAME(c0_badvaddr, cp0_badvaddr),
 823         REG_OFFSET_NAME(c0_cause, cp0_cause),
 824         REG_OFFSET_NAME(c0_epc, cp0_epc),
 825 #ifdef CONFIG_CPU_CAVIUM_OCTEON
 826         REG_OFFSET_NAME(mpl0, mpl[0]),
 827         REG_OFFSET_NAME(mpl1, mpl[1]),
 828         REG_OFFSET_NAME(mpl2, mpl[2]),
 829         REG_OFFSET_NAME(mtp0, mtp[0]),
 830         REG_OFFSET_NAME(mtp1, mtp[1]),
 831         REG_OFFSET_NAME(mtp2, mtp[2]),
 832 #endif
 833         REG_OFFSET_END,
 834 };
 835
 836 /**
 837  * regs_query_register_offset() - query register offset from its name
 838  * @name:       the name of a register
 839  *
 840  * regs_query_register_offset() returns the offset of a register in struct
 841  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 842  */
 843 int regs_query_register_offset(const char *name)
 844 {
 845         const struct pt_regs_offset *roff;
 846         for (roff = regoffset_table; roff->name != NULL; roff++)
 847                 if (!strcmp(roff->name, name))
 848                         return roff->offset;
 849         return -EINVAL;
 850 }
 851
 852 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
 853
 854 static const struct user_regset mips_regsets[] = {
 855         [REGSET_GPR] = {
 856                 .core_note_type = NT_PRSTATUS,
 857                 .n              = ELF_NGREG,
 858                 .size           = sizeof(unsigned int),
 859                 .align          = sizeof(unsigned int),
 860                 .get            = gpr32_get,
 861                 .set            = gpr32_set,
 862         },
 863         [REGSET_FPR] = {
 864                 .core_note_type = NT_PRFPREG,
 865                 .n              = ELF_NFPREG,
 866                 .size           = sizeof(elf_fpreg_t),
 867                 .align          = sizeof(elf_fpreg_t),
 868                 .get            = fpr_get,
 869                 .set            = fpr_set,
 870         },
 871         [REGSET_DSP] = {
 872                 .core_note_type = NT_MIPS_DSP,
 873                 .n              = NUM_DSP_REGS + 1,
 874                 .size           = sizeof(u32),
 875                 .align          = sizeof(u32),
 876                 .get            = dsp32_get,
 877                 .set            = dsp32_set,
 878                 .active         = dsp_active,
 879         },
 880 };
 881
 882 static const struct user_regset_view user_mips_view = {
 883         .name           = "mips",
 884         .e_machine      = ELF_ARCH,
 885         .ei_osabi       = ELF_OSABI,
 886         .regsets        = mips_regsets,
 887         .n              = ARRAY_SIZE(mips_regsets),
 888 };
 889
 890 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
 891
 892 #ifdef CONFIG_64BIT
 893
 894 static const struct user_regset mips64_regsets[] = {
 895         [REGSET_GPR] = {
 896                 .core_note_type = NT_PRSTATUS,
 897                 .n              = ELF_NGREG,
 898                 .size           = sizeof(unsigned long),
 899                 .align          = sizeof(unsigned long),
 900                 .get            = gpr64_get,
 901                 .set            = gpr64_set,
 902         },
 903         [REGSET_FPR] = {
 904                 .core_note_type = NT_PRFPREG,
 905                 .n              = ELF_NFPREG,
 906                 .size           = sizeof(elf_fpreg_t),
 907                 .align          = sizeof(elf_fpreg_t),
 908                 .get            = fpr_get,
 909                 .set            = fpr_set,
 910         },
 911         [REGSET_DSP] = {
 912                 .core_note_type = NT_MIPS_DSP,
 913                 .n              = NUM_DSP_REGS + 1,
 914                 .size           = sizeof(u64),
 915                 .align          = sizeof(u64),
 916                 .get            = dsp64_get,
 917                 .set            = dsp64_set,
 918                 .active         = dsp_active,
 919         },
 920 };
 921
 922 static const struct user_regset_view user_mips64_view = {
 923         .name           = "mips64",
 924         .e_machine      = ELF_ARCH,
 925         .ei_osabi       = ELF_OSABI,
 926         .regsets        = mips64_regsets,
 927         .n              = ARRAY_SIZE(mips64_regsets),
 928 };
 929
 930 #ifdef CONFIG_MIPS32_N32
 931
 932 static const struct user_regset_view user_mipsn32_view = {
 933         .name           = "mipsn32",
 934         .e_flags        = EF_MIPS_ABI2,
 935         .e_machine      = ELF_ARCH,
 936         .ei_osabi       = ELF_OSABI,
 937         .regsets        = mips64_regsets,
 938         .n              = ARRAY_SIZE(mips64_regsets),
 939 };
 940
 941 #endif /* CONFIG_MIPS32_N32 */
 942
 943 #endif /* CONFIG_64BIT */
 944
 945 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 946 {
 947 #ifdef CONFIG_32BIT
 948         return &user_mips_view;
 949 #else
 950 #ifdef CONFIG_MIPS32_O32
 951         if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
 952                 return &user_mips_view;
 953 #endif
 954 #ifdef CONFIG_MIPS32_N32
 955         if (test_tsk_thread_flag(task, TIF_32BIT_ADDR))
 956                 return &user_mipsn32_view;
 957 #endif
 958         return &user_mips64_view;
 959 #endif
 960 }
 961
 962 long arch_ptrace(struct task_struct *child, long request,
 963                  unsigned long addr, unsigned long data)
 964 {
 965         int ret;
 966         void __user *addrp = (void __user *) addr;
 967         void __user *datavp = (void __user *) data;
 968         unsigned long __user *datalp = (void __user *) data;
 969
 970         switch (request) {
 971         /* when I and D space are separate, these will need to be fixed. */
 972         case PTRACE_PEEKTEXT: /* read word at location addr. */
 973         case PTRACE_PEEKDATA:
 974                 ret = generic_ptrace_peekdata(child, addr, data);
 975                 break;
 976
 977         /* Read the word at location addr in the USER area. */
 978         case PTRACE_PEEKUSR: {
 979                 struct pt_regs *regs;
 980                 union fpureg *fregs;
 981                 unsigned long tmp = 0;
 982
 983                 regs = task_pt_regs(child);
 984                 ret = 0;  /* Default return value. */
 985
 986                 switch (addr) {
 987                 case 0 ... 31:
 988                         tmp = regs->regs[addr];
 989                         break;
 990                 case FPR_BASE ... FPR_BASE + 31:
 991                         if (!tsk_used_math(child)) {
 992                                 /* FP not yet used */
 993                                 tmp = -1;
 994                                 break;
 995                         }
 996                         fregs = get_fpu_regs(child);
 997
 998 #ifdef CONFIG_32BIT
 999                         if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
1000                                 /*
1001                                  * The odd registers are actually the high
1002                                  * order bits of the values stored in the even
1003                                  * registers.
1004                                  */
1005                                 tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
1006                                                 addr & 1);
1007                                 break;
1008                         }
1009 #endif
1010                         tmp = get_fpr64(&fregs[addr - FPR_BASE], 0);
1011                         break;
1012                 case PC:
1013                         tmp = regs->cp0_epc;
1014                         break;
1015                 case CAUSE:
1016                         tmp = regs->cp0_cause;
1017                         break;
1018                 case BADVADDR:
1019                         tmp = regs->cp0_badvaddr;
1020                         break;
1021                 case MMHI:
1022                         tmp = regs->hi;
1023                         break;
1024                 case MMLO:
1025                         tmp = regs->lo;
1026                         break;
1027 #ifdef CONFIG_CPU_HAS_SMARTMIPS
1028                 case ACX:
1029                         tmp = regs->acx;
1030                         break;
1031 #endif
1032                 case FPC_CSR:
1033                         tmp = child->thread.fpu.fcr31;
1034                         break;
1035                 case FPC_EIR:
1036                         /* implementation / version register */
1037                         tmp = boot_cpu_data.fpu_id;
1038                         break;
1039                 case DSP_BASE ... DSP_BASE + 5: {
1040                         dspreg_t *dregs;
1041
1042                         if (!cpu_has_dsp) {
1043                                 tmp = 0;
1044                                 ret = -EIO;
1045                                 goto out;
1046                         }
1047                         dregs = __get_dsp_regs(child);
1048                         tmp = dregs[addr - DSP_BASE];
1049                         break;
1050                 }
1051                 case DSP_CONTROL:
1052                         if (!cpu_has_dsp) {
1053                                 tmp = 0;
1054                                 ret = -EIO;
1055                                 goto out;
1056                         }
1057                         tmp = child->thread.dsp.dspcontrol;
1058                         break;
1059                 default:
1060                         tmp = 0;
1061                         ret = -EIO;
1062                         goto out;
1063                 }
1064                 ret = put_user(tmp, datalp);
1065                 break;
1066         }
1067
1068         /* when I and D space are separate, this will have to be fixed. */
1069         case PTRACE_POKETEXT: /* write the word at location addr. */
1070         case PTRACE_POKEDATA:
1071                 ret = generic_ptrace_pokedata(child, addr, data);
1072                 break;
1073
1074         case PTRACE_POKEUSR: {
1075                 struct pt_regs *regs;
1076                 ret = 0;
1077                 regs = task_pt_regs(child);
1078
1079                 switch (addr) {
1080                 case 0 ... 31:
1081                         regs->regs[addr] = data;
1082                         /* System call number may have been changed */
1083                         if (addr == 2)
1084                                 mips_syscall_update_nr(child, regs);
1085                         else if (addr == 4 &&
1086                                  mips_syscall_is_indirect(child, regs))
1087                                 mips_syscall_update_nr(child, regs);
1088                         break;
1089                 case FPR_BASE ... FPR_BASE + 31: {
1090                         union fpureg *fregs = get_fpu_regs(child);
1091
1092                         init_fp_ctx(child);
1093 #ifdef CONFIG_32BIT
1094                         if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
1095                                 /*
1096                                  * The odd registers are actually the high
1097                                  * order bits of the values stored in the even
1098                                  * registers.
1099                                  */
1100                                 set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
1101                                           addr & 1, data);
1102                                 break;
1103                         }
1104 #endif
1105                         set_fpr64(&fregs[addr - FPR_BASE], 0, data);
1106                         break;
1107                 }
1108                 case PC:
1109                         regs->cp0_epc = data;
1110                         break;
1111                 case MMHI:
1112                         regs->hi = data;
1113                         break;
1114                 case MMLO:
1115                         regs->lo = data;
1116                         break;
1117 #ifdef CONFIG_CPU_HAS_SMARTMIPS
1118                 case ACX:
1119                         regs->acx = data;
1120                         break;
1121 #endif
1122                 case FPC_CSR:
1123                         init_fp_ctx(child);
1124                         ptrace_setfcr31(child, data);
1125                         break;
1126                 case DSP_BASE ... DSP_BASE + 5: {
1127                         dspreg_t *dregs;
1128
1129                         if (!cpu_has_dsp) {
1130                                 ret = -EIO;
1131                                 break;
1132                         }
1133
1134                         dregs = __get_dsp_regs(child);
1135                         dregs[addr - DSP_BASE] = data;
1136                         break;
1137                 }
1138                 case DSP_CONTROL:
1139                         if (!cpu_has_dsp) {
1140                                 ret = -EIO;
1141                                 break;
1142                         }
1143                         child->thread.dsp.dspcontrol = data;
1144                         break;
1145                 default:
1146                         /* The rest are not allowed. */
1147                         ret = -EIO;
1148                         break;
1149                 }
1150                 break;
1151                 }
1152
1153         case PTRACE_GETREGS:
1154                 ret = ptrace_getregs(child, datavp);
1155                 break;
1156
1157         case PTRACE_SETREGS:
1158                 ret = ptrace_setregs(child, datavp);
1159                 break;
1160
1161         case PTRACE_GETFPREGS:
1162                 ret = ptrace_getfpregs(child, datavp);
1163                 break;
1164
1165         case PTRACE_SETFPREGS:
1166                 ret = ptrace_setfpregs(child, datavp);
1167                 break;
1168
1169         case PTRACE_GET_THREAD_AREA:
1170                 ret = put_user(task_thread_info(child)->tp_value, datalp);
1171                 break;
1172
1173         case PTRACE_GET_WATCH_REGS:
1174                 ret = ptrace_get_watch_regs(child, addrp);
1175                 break;
1176
1177         case PTRACE_SET_WATCH_REGS:
1178                 ret = ptrace_set_watch_regs(child, addrp);
1179                 break;
1180
1181         default:
1182                 ret = ptrace_request(child, request, addr, data);
1183                 break;
1184         }
1185  out:
1186         return ret;
1187 }
1188
1189 /*
1190  * Notification of system call entry/exit
1191  * - triggered by current->work.syscall_trace
1192  */
1193 asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
1194 {
1195         user_exit();
1196
1197         current_thread_info()->syscall = syscall;
1198
1199         if (test_thread_flag(TIF_SYSCALL_TRACE)) {
1200                 if (tracehook_report_syscall_entry(regs))
1201                         return -1;
1202                 syscall = current_thread_info()->syscall;
1203         }
1204
1205 #ifdef CONFIG_SECCOMP
1206         if (unlikely(test_thread_flag(TIF_SECCOMP))) {
1207                 int ret, i;
1208                 struct seccomp_data sd;
1209                 unsigned long args[6];
1210
1211                 sd.nr = syscall;
1212                 sd.arch = syscall_get_arch();
1213                 syscall_get_arguments(current, regs, 0, 6, args);
1214                 for (i = 0; i < 6; i++)
1215                         sd.args[i] = args[i];
1216                 sd.instruction_pointer = KSTK_EIP(current);
1217
1218                 ret = __secure_computing(&sd);
1219                 if (ret == -1)
1220                         return ret;
1221                 syscall = current_thread_info()->syscall;
1222         }
1223 #endif
1224
1225         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1226                 trace_sys_enter(regs, regs->regs[2]);
1227
1228         audit_syscall_entry(syscall, regs->regs[4], regs->regs[5],
1229                             regs->regs[6], regs->regs[7]);
1230
1231         /*
1232          * Negative syscall numbers are mistaken for rejected syscalls, but
1233          * won't have had the return value set appropriately, so we do so now.
1234          */
1235         if (syscall < 0)
1236                 syscall_set_return_value(current, regs, -ENOSYS, 0);
1237         return syscall;
1238 }
1239
1240 /*
1241  * Notification of system call entry/exit
1242  * - triggered by current->work.syscall_trace
1243  */
1244 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
1245 {
1246         /*
1247          * We may come here right after calling schedule_user()
1248          * or do_notify_resume(), in which case we can be in RCU
1249          * user mode.
1250          */
1251         user_exit();
1252
1253         audit_syscall_exit(regs);
1254
1255         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1256                 trace_sys_exit(regs, regs_return_value(regs));
1257
1258         if (test_thread_flag(TIF_SYSCALL_TRACE))
1259                 tracehook_report_syscall_exit(regs, 0);
1260
1261         user_enter();
1262 }