arch/arm64/kernel/ptrace.c

   1 /*
   2  * Based on arch/arm/kernel/ptrace.c
   3  *
   4  * By Ross Biro 1/23/92
   5  * edited by Linus Torvalds
   6  * ARM modifications Copyright (C) 2000 Russell King
   7  * Copyright (C) 2012 ARM Ltd.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/sched.h>
  24 #include <linux/mm.h>
  25 #include <linux/smp.h>
  26 #include <linux/ptrace.h>
  27 #include <linux/user.h>
  28 #include <linux/security.h>
  29 #include <linux/init.h>
  30 #include <linux/signal.h>
  31 #include <linux/uaccess.h>
  32 #include <linux/perf_event.h>
  33 #include <linux/hw_breakpoint.h>
  34 #include <linux/regset.h>
  35 #include <linux/tracehook.h>
  36 #include <linux/elf.h>
  37
  38 #include <asm/compat.h>
  39 #include <asm/debug-monitors.h>
  40 #include <asm/pgtable.h>
  41 #include <asm/traps.h>
  42 #include <asm/system_misc.h>
  43
  44 /*
  45  * TODO: does not yet catch signals sent when the child dies.
  46  * in exit.c or in signal.c.
  47  */
  48
  49 /*
  50  * Called by kernel/ptrace.c when detaching..
  51  */
  52 void ptrace_disable(struct task_struct *child)
  53 {
  54 }
  55
  56 #ifdef CONFIG_HAVE_HW_BREAKPOINT
  57 /*
  58  * Handle hitting a HW-breakpoint.
  59  */
  60 static void ptrace_hbptriggered(struct perf_event *bp,
  61                                 struct perf_sample_data *data,
  62                                 struct pt_regs *regs)
  63 {
  64         struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
  65         siginfo_t info = {
  66                 .si_signo       = SIGTRAP,
  67                 .si_errno       = 0,
  68                 .si_code        = TRAP_HWBKPT,
  69                 .si_addr        = (void __user *)(bkpt->trigger),
  70         };
  71
  72 #ifdef CONFIG_COMPAT
  73         int i;
  74
  75         if (!is_compat_task())
  76                 goto send_sig;
  77
  78         for (i = 0; i < ARM_MAX_BRP; ++i) {
  79                 if (current->thread.debug.hbp_break[i] == bp) {
  80                         info.si_errno = (i << 1) + 1;
  81                         break;
  82                 }
  83         }
  84         for (i = ARM_MAX_BRP; i < ARM_MAX_HBP_SLOTS && !bp; ++i) {
  85                 if (current->thread.debug.hbp_watch[i] == bp) {
  86                         info.si_errno = -((i << 1) + 1);
  87                         break;
  88                 }
  89         }
  90
  91 send_sig:
  92 #endif
  93         force_sig_info(SIGTRAP, &info, current);
  94 }
  95
  96 /*
  97  * Unregister breakpoints from this task and reset the pointers in
  98  * the thread_struct.
  99  */
 100 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 101 {
 102         int i;
 103         struct thread_struct *t = &tsk->thread;
 104
 105         for (i = 0; i < ARM_MAX_BRP; i++) {
 106                 if (t->debug.hbp_break[i]) {
 107                         unregister_hw_breakpoint(t->debug.hbp_break[i]);
 108                         t->debug.hbp_break[i] = NULL;
 109                 }
 110         }
 111
 112         for (i = 0; i < ARM_MAX_WRP; i++) {
 113                 if (t->debug.hbp_watch[i]) {
 114                         unregister_hw_breakpoint(t->debug.hbp_watch[i]);
 115                         t->debug.hbp_watch[i] = NULL;
 116                 }
 117         }
 118 }
 119
 120 void ptrace_hw_copy_thread(struct task_struct *tsk)
 121 {
 122         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 123 }
 124
 125 static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
 126                                                struct task_struct *tsk,
 127                                                unsigned long idx)
 128 {
 129         struct perf_event *bp = ERR_PTR(-EINVAL);
 130
 131         switch (note_type) {
 132         case NT_ARM_HW_BREAK:
 133                 if (idx < ARM_MAX_BRP)
 134                         bp = tsk->thread.debug.hbp_break[idx];
 135                 break;
 136         case NT_ARM_HW_WATCH:
 137                 if (idx < ARM_MAX_WRP)
 138                         bp = tsk->thread.debug.hbp_watch[idx];
 139                 break;
 140         }
 141
 142         return bp;
 143 }
 144
 145 static int ptrace_hbp_set_event(unsigned int note_type,
 146                                 struct task_struct *tsk,
 147                                 unsigned long idx,
 148                                 struct perf_event *bp)
 149 {
 150         int err = -EINVAL;
 151
 152         switch (note_type) {
 153         case NT_ARM_HW_BREAK:
 154                 if (idx < ARM_MAX_BRP) {
 155                         tsk->thread.debug.hbp_break[idx] = bp;
 156                         err = 0;
 157                 }
 158                 break;
 159         case NT_ARM_HW_WATCH:
 160                 if (idx < ARM_MAX_WRP) {
 161                         tsk->thread.debug.hbp_watch[idx] = bp;
 162                         err = 0;
 163                 }
 164                 break;
 165         }
 166
 167         return err;
 168 }
 169
 170 static struct perf_event *ptrace_hbp_create(unsigned int note_type,
 171                                             struct task_struct *tsk,
 172                                             unsigned long idx)
 173 {
 174         struct perf_event *bp;
 175         struct perf_event_attr attr;
 176         int err, type;
 177
 178         switch (note_type) {
 179         case NT_ARM_HW_BREAK:
 180                 type = HW_BREAKPOINT_X;
 181                 break;
 182         case NT_ARM_HW_WATCH:
 183                 type = HW_BREAKPOINT_RW;
 184                 break;
 185         default:
 186                 return ERR_PTR(-EINVAL);
 187         }
 188
 189         ptrace_breakpoint_init(&attr);
 190
 191         /*
 192          * Initialise fields to sane defaults
 193          * (i.e. values that will pass validation).
 194          */
 195         attr.bp_addr    = 0;
 196         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 197         attr.bp_type    = type;
 198         attr.disabled   = 1;
 199
 200         bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk);
 201         if (IS_ERR(bp))
 202                 return bp;
 203
 204         err = ptrace_hbp_set_event(note_type, tsk, idx, bp);
 205         if (err)
 206                 return ERR_PTR(err);
 207
 208         return bp;
 209 }
 210
 211 static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
 212                                      struct arch_hw_breakpoint_ctrl ctrl,
 213                                      struct perf_event_attr *attr)
 214 {
 215         int err, len, type, disabled = !ctrl.enabled;
 216
 217         if (disabled) {
 218                 len = 0;
 219                 type = HW_BREAKPOINT_EMPTY;
 220         } else {
 221                 err = arch_bp_generic_fields(ctrl, &len, &type);
 222                 if (err)
 223                         return err;
 224
 225                 switch (note_type) {
 226                 case NT_ARM_HW_BREAK:
 227                         if ((type & HW_BREAKPOINT_X) != type)
 228                                 return -EINVAL;
 229                         break;
 230                 case NT_ARM_HW_WATCH:
 231                         if ((type & HW_BREAKPOINT_RW) != type)
 232                                 return -EINVAL;
 233                         break;
 234                 default:
 235                         return -EINVAL;
 236                 }
 237         }
 238
 239         attr->bp_len    = len;
 240         attr->bp_type   = type;
 241         attr->disabled  = disabled;
 242
 243         return 0;
 244 }
 245
 246 static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info)
 247 {
 248         u8 num;
 249         u32 reg = 0;
 250
 251         switch (note_type) {
 252         case NT_ARM_HW_BREAK:
 253                 num = hw_breakpoint_slots(TYPE_INST);
 254                 break;
 255         case NT_ARM_HW_WATCH:
 256                 num = hw_breakpoint_slots(TYPE_DATA);
 257                 break;
 258         default:
 259                 return -EINVAL;
 260         }
 261
 262         reg |= debug_monitors_arch();
 263         reg <<= 8;
 264         reg |= num;
 265
 266         *info = reg;
 267         return 0;
 268 }
 269
 270 static int ptrace_hbp_get_ctrl(unsigned int note_type,
 271                                struct task_struct *tsk,
 272                                unsigned long idx,
 273                                u32 *ctrl)
 274 {
 275         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 276
 277         if (IS_ERR(bp))
 278                 return PTR_ERR(bp);
 279
 280         *ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0;
 281         return 0;
 282 }
 283
 284 static int ptrace_hbp_get_addr(unsigned int note_type,
 285                                struct task_struct *tsk,
 286                                unsigned long idx,
 287                                u64 *addr)
 288 {
 289         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 290
 291         if (IS_ERR(bp))
 292                 return PTR_ERR(bp);
 293
 294         *addr = bp ? bp->attr.bp_addr : 0;
 295         return 0;
 296 }
 297
 298 static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type,
 299                                                         struct task_struct *tsk,
 300                                                         unsigned long idx)
 301 {
 302         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 303
 304         if (!bp)
 305                 bp = ptrace_hbp_create(note_type, tsk, idx);
 306
 307         return bp;
 308 }
 309
 310 static int ptrace_hbp_set_ctrl(unsigned int note_type,
 311                                struct task_struct *tsk,
 312                                unsigned long idx,
 313                                u32 uctrl)
 314 {
 315         int err;
 316         struct perf_event *bp;
 317         struct perf_event_attr attr;
 318         struct arch_hw_breakpoint_ctrl ctrl;
 319
 320         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 321         if (IS_ERR(bp)) {
 322                 err = PTR_ERR(bp);
 323                 return err;
 324         }
 325
 326         attr = bp->attr;
 327         decode_ctrl_reg(uctrl, &ctrl);
 328         err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
 329         if (err)
 330                 return err;
 331
 332         return modify_user_hw_breakpoint(bp, &attr);
 333 }
 334
 335 static int ptrace_hbp_set_addr(unsigned int note_type,
 336                                struct task_struct *tsk,
 337                                unsigned long idx,
 338                                u64 addr)
 339 {
 340         int err;
 341         struct perf_event *bp;
 342         struct perf_event_attr attr;
 343
 344         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 345         if (IS_ERR(bp)) {
 346                 err = PTR_ERR(bp);
 347                 return err;
 348         }
 349
 350         attr = bp->attr;
 351         attr.bp_addr = addr;
 352         err = modify_user_hw_breakpoint(bp, &attr);
 353         return err;
 354 }
 355
 356 #define PTRACE_HBP_ADDR_SZ      sizeof(u64)
 357 #define PTRACE_HBP_CTRL_SZ      sizeof(u32)
 358 #define PTRACE_HBP_PAD_SZ       sizeof(u32)
 359
 360 static int hw_break_get(struct task_struct *target,
 361                         const struct user_regset *regset,
 362                         unsigned int pos, unsigned int count,
 363                         void *kbuf, void __user *ubuf)
 364 {
 365         unsigned int note_type = regset->core_note_type;
 366         int ret, idx = 0, offset, limit;
 367         u32 info, ctrl;
 368         u64 addr;
 369
 370         /* Resource info */
 371         ret = ptrace_hbp_get_resource_info(note_type, &info);
 372         if (ret)
 373                 return ret;
 374
 375         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0,
 376                                   sizeof(info));
 377         if (ret)
 378                 return ret;
 379
 380         /* Pad */
 381         offset = offsetof(struct user_hwdebug_state, pad);
 382         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, offset,
 383                                        offset + PTRACE_HBP_PAD_SZ);
 384         if (ret)
 385                 return ret;
 386
 387         /* (address, ctrl) registers */
 388         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 389         limit = regset->n * regset->size;
 390         while (count && offset < limit) {
 391                 ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
 392                 if (ret)
 393                         return ret;
 394                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr,
 395                                           offset, offset + PTRACE_HBP_ADDR_SZ);
 396                 if (ret)
 397                         return ret;
 398                 offset += PTRACE_HBP_ADDR_SZ;
 399
 400                 ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
 401                 if (ret)
 402                         return ret;
 403                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl,
 404                                           offset, offset + PTRACE_HBP_CTRL_SZ);
 405                 if (ret)
 406                         return ret;
 407                 offset += PTRACE_HBP_CTRL_SZ;
 408
 409                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 410                                                offset,
 411                                                offset + PTRACE_HBP_PAD_SZ);
 412                 if (ret)
 413                         return ret;
 414                 offset += PTRACE_HBP_PAD_SZ;
 415                 idx++;
 416         }
 417
 418         return 0;
 419 }
 420
 421 static int hw_break_set(struct task_struct *target,
 422                         const struct user_regset *regset,
 423                         unsigned int pos, unsigned int count,
 424                         const void *kbuf, const void __user *ubuf)
 425 {
 426         unsigned int note_type = regset->core_note_type;
 427         int ret, idx = 0, offset, limit;
 428         u32 ctrl;
 429         u64 addr;
 430
 431         /* Resource info and pad */
 432         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 433         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset);
 434         if (ret)
 435                 return ret;
 436
 437         /* (address, ctrl) registers */
 438         limit = regset->n * regset->size;
 439         while (count && offset < limit) {
 440                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
 441                                          offset, offset + PTRACE_HBP_ADDR_SZ);
 442                 if (ret)
 443                         return ret;
 444                 ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
 445                 if (ret)
 446                         return ret;
 447                 offset += PTRACE_HBP_ADDR_SZ;
 448
 449                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
 450                                          offset, offset + PTRACE_HBP_CTRL_SZ);
 451                 if (ret)
 452                         return ret;
 453                 ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
 454                 if (ret)
 455                         return ret;
 456                 offset += PTRACE_HBP_CTRL_SZ;
 457
 458                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 459                                                 offset,
 460                                                 offset + PTRACE_HBP_PAD_SZ);
 461                 if (ret)
 462                         return ret;
 463                 offset += PTRACE_HBP_PAD_SZ;
 464                 idx++;
 465         }
 466
 467         return 0;
 468 }
 469 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 470
 471 static int gpr_get(struct task_struct *target,
 472                    const struct user_regset *regset,
 473                    unsigned int pos, unsigned int count,
 474                    void *kbuf, void __user *ubuf)
 475 {
 476         struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
 477         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 478 }
 479
 480 static int gpr_set(struct task_struct *target, const struct user_regset *regset,
 481                    unsigned int pos, unsigned int count,
 482                    const void *kbuf, const void __user *ubuf)
 483 {
 484         int ret;
 485         struct user_pt_regs newregs;
 486
 487         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
 488         if (ret)
 489                 return ret;
 490
 491         if (!valid_user_regs(&newregs))
 492                 return -EINVAL;
 493
 494         task_pt_regs(target)->user_regs = newregs;
 495         return 0;
 496 }
 497
 498 /*
 499  * TODO: update fp accessors for lazy context switching (sync/flush hwstate)
 500  */
 501 static int fpr_get(struct task_struct *target, const struct user_regset *regset,
 502                    unsigned int pos, unsigned int count,
 503                    void *kbuf, void __user *ubuf)
 504 {
 505         struct user_fpsimd_state *uregs;
 506         uregs = &target->thread.fpsimd_state.user_fpsimd;
 507         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 508 }
 509
 510 static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 511                    unsigned int pos, unsigned int count,
 512                    const void *kbuf, const void __user *ubuf)
 513 {
 514         int ret;
 515         struct user_fpsimd_state newstate;
 516
 517         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1);
 518         if (ret)
 519                 return ret;
 520
 521         target->thread.fpsimd_state.user_fpsimd = newstate;
 522         return ret;
 523 }
 524
 525 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 526                    unsigned int pos, unsigned int count,
 527                    void *kbuf, void __user *ubuf)
 528 {
 529         unsigned long *tls = &target->thread.tp_value;
 530         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
 531 }
 532
 533 static int tls_set(struct task_struct *target, const struct user_regset *regset,
 534                    unsigned int pos, unsigned int count,
 535                    const void *kbuf, const void __user *ubuf)
 536 {
 537         int ret;
 538         unsigned long tls;
 539
 540         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 541         if (ret)
 542                 return ret;
 543
 544         target->thread.tp_value = tls;
 545         return ret;
 546 }
 547
 548 enum aarch64_regset {
 549         REGSET_GPR,
 550         REGSET_FPR,
 551         REGSET_TLS,
 552 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 553         REGSET_HW_BREAK,
 554         REGSET_HW_WATCH,
 555 #endif
 556 };
 557
 558 static const struct user_regset aarch64_regsets[] = {
 559         [REGSET_GPR] = {
 560                 .core_note_type = NT_PRSTATUS,
 561                 .n = sizeof(struct user_pt_regs) / sizeof(u64),
 562                 .size = sizeof(u64),
 563                 .align = sizeof(u64),
 564                 .get = gpr_get,
 565                 .set = gpr_set
 566         },
 567         [REGSET_FPR] = {
 568                 .core_note_type = NT_PRFPREG,
 569                 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
 570                 /*
 571                  * We pretend we have 32-bit registers because the fpsr and
 572                  * fpcr are 32-bits wide.
 573                  */
 574                 .size = sizeof(u32),
 575                 .align = sizeof(u32),
 576                 .get = fpr_get,
 577                 .set = fpr_set
 578         },
 579         [REGSET_TLS] = {
 580                 .core_note_type = NT_ARM_TLS,
 581                 .n = 1,
 582                 .size = sizeof(void *),
 583                 .align = sizeof(void *),
 584                 .get = tls_get,
 585                 .set = tls_set,
 586         },
 587 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 588         [REGSET_HW_BREAK] = {
 589                 .core_note_type = NT_ARM_HW_BREAK,
 590                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 591                 .size = sizeof(u32),
 592                 .align = sizeof(u32),
 593                 .get = hw_break_get,
 594                 .set = hw_break_set,
 595         },
 596         [REGSET_HW_WATCH] = {
 597                 .core_note_type = NT_ARM_HW_WATCH,
 598                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 599                 .size = sizeof(u32),
 600                 .align = sizeof(u32),
 601                 .get = hw_break_get,
 602                 .set = hw_break_set,
 603         },
 604 #endif
 605 };
 606
 607 static const struct user_regset_view user_aarch64_view = {
 608         .name = "aarch64", .e_machine = EM_AARCH64,
 609         .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
 610 };
 611
 612 #ifdef CONFIG_COMPAT
 613 #include <linux/compat.h>
 614
 615 enum compat_regset {
 616         REGSET_COMPAT_GPR,
 617         REGSET_COMPAT_VFP,
 618 };
 619
 620 static int compat_gpr_get(struct task_struct *target,
 621                           const struct user_regset *regset,
 622                           unsigned int pos, unsigned int count,
 623                           void *kbuf, void __user *ubuf)
 624 {
 625         int ret = 0;
 626         unsigned int i, start, num_regs;
 627
 628         /* Calculate the number of AArch32 registers contained in count */
 629         num_regs = count / regset->size;
 630
 631         /* Convert pos into an register number */
 632         start = pos / regset->size;
 633
 634         if (start + num_regs > regset->n)
 635                 return -EIO;
 636
 637         for (i = 0; i < num_regs; ++i) {
 638                 unsigned int idx = start + i;
 639                 compat_ulong_t reg;
 640
 641                 switch (idx) {
 642                 case 15:
 643                         reg = task_pt_regs(target)->pc;
 644                         break;
 645                 case 16:
 646                         reg = task_pt_regs(target)->pstate;
 647                         break;
 648                 case 17:
 649                         reg = task_pt_regs(target)->orig_x0;
 650                         break;
 651                 default:
 652                         reg = task_pt_regs(target)->regs[idx];
 653                 }
 654
 655                 ret = copy_to_user(ubuf, &reg, sizeof(reg));
 656                 if (ret)
 657                         break;
 658
 659                 ubuf += sizeof(reg);
 660         }
 661
 662         return ret;
 663 }
 664
 665 static int compat_gpr_set(struct task_struct *target,
 666                           const struct user_regset *regset,
 667                           unsigned int pos, unsigned int count,
 668                           const void *kbuf, const void __user *ubuf)
 669 {
 670         struct pt_regs newregs;
 671         int ret = 0;
 672         unsigned int i, start, num_regs;
 673
 674         /* Calculate the number of AArch32 registers contained in count */
 675         num_regs = count / regset->size;
 676
 677         /* Convert pos into an register number */
 678         start = pos / regset->size;
 679
 680         if (start + num_regs > regset->n)
 681                 return -EIO;
 682
 683         newregs = *task_pt_regs(target);
 684
 685         for (i = 0; i < num_regs; ++i) {
 686                 unsigned int idx = start + i;
 687                 compat_ulong_t reg;
 688
 689                 ret = copy_from_user(&reg, ubuf, sizeof(reg));
 690                 if (ret)
 691                         return ret;
 692
 693                 ubuf += sizeof(reg);
 694
 695                 switch (idx) {
 696                 case 15:
 697                         newregs.pc = reg;
 698                         break;
 699                 case 16:
 700                         newregs.pstate = reg;
 701                         break;
 702                 case 17:
 703                         newregs.orig_x0 = reg;
 704                         break;
 705                 default:
 706                         newregs.regs[idx] = reg;
 707                 }
 708
 709         }
 710
 711         if (valid_user_regs(&newregs.user_regs))
 712                 *task_pt_regs(target) = newregs;
 713         else
 714                 ret = -EINVAL;
 715
 716         return ret;
 717 }
 718
 719 static int compat_vfp_get(struct task_struct *target,
 720                           const struct user_regset *regset,
 721                           unsigned int pos, unsigned int count,
 722                           void *kbuf, void __user *ubuf)
 723 {
 724         struct user_fpsimd_state *uregs;
 725         compat_ulong_t fpscr;
 726         int ret;
 727
 728         uregs = &target->thread.fpsimd_state.user_fpsimd;
 729
 730         /*
 731          * The VFP registers are packed into the fpsimd_state, so they all sit
 732          * nicely together for us. We just need to create the fpscr separately.
 733          */
 734         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
 735                                   VFP_STATE_SIZE - sizeof(compat_ulong_t));
 736
 737         if (count && !ret) {
 738                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
 739                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
 740                 ret = put_user(fpscr, (compat_ulong_t *)ubuf);
 741         }
 742
 743         return ret;
 744 }
 745
 746 static int compat_vfp_set(struct task_struct *target,
 747                           const struct user_regset *regset,
 748                           unsigned int pos, unsigned int count,
 749                           const void *kbuf, const void __user *ubuf)
 750 {
 751         struct user_fpsimd_state *uregs;
 752         compat_ulong_t fpscr;
 753         int ret;
 754
 755         if (pos + count > VFP_STATE_SIZE)
 756                 return -EIO;
 757
 758         uregs = &target->thread.fpsimd_state.user_fpsimd;
 759
 760         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
 761                                  VFP_STATE_SIZE - sizeof(compat_ulong_t));
 762
 763         if (count && !ret) {
 764                 ret = get_user(fpscr, (compat_ulong_t *)ubuf);
 765                 uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
 766                 uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
 767         }
 768
 769         return ret;
 770 }
 771
 772 static const struct user_regset aarch32_regsets[] = {
 773         [REGSET_COMPAT_GPR] = {
 774                 .core_note_type = NT_PRSTATUS,
 775                 .n = COMPAT_ELF_NGREG,
 776                 .size = sizeof(compat_elf_greg_t),
 777                 .align = sizeof(compat_elf_greg_t),
 778                 .get = compat_gpr_get,
 779                 .set = compat_gpr_set
 780         },
 781         [REGSET_COMPAT_VFP] = {
 782                 .core_note_type = NT_ARM_VFP,
 783                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
 784                 .size = sizeof(compat_ulong_t),
 785                 .align = sizeof(compat_ulong_t),
 786                 .get = compat_vfp_get,
 787                 .set = compat_vfp_set
 788         },
 789 };
 790
 791 static const struct user_regset_view user_aarch32_view = {
 792         .name = "aarch32", .e_machine = EM_ARM,
 793         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
 794 };
 795
 796 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
 797                                    compat_ulong_t __user *ret)
 798 {
 799         compat_ulong_t tmp;
 800
 801         if (off & 3)
 802                 return -EIO;
 803
 804         if (off == COMPAT_PT_TEXT_ADDR)
 805                 tmp = tsk->mm->start_code;
 806         else if (off == COMPAT_PT_DATA_ADDR)
 807                 tmp = tsk->mm->start_data;
 808         else if (off == COMPAT_PT_TEXT_END_ADDR)
 809                 tmp = tsk->mm->end_code;
 810         else if (off < sizeof(compat_elf_gregset_t))
 811                 return copy_regset_to_user(tsk, &user_aarch32_view,
 812                                            REGSET_COMPAT_GPR, off,
 813                                            sizeof(compat_ulong_t), ret);
 814         else if (off >= COMPAT_USER_SZ)
 815                 return -EIO;
 816         else
 817                 tmp = 0;
 818
 819         return put_user(tmp, ret);
 820 }
 821
 822 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
 823                                     compat_ulong_t val)
 824 {
 825         int ret;
 826
 827         if (off & 3 || off >= COMPAT_USER_SZ)
 828                 return -EIO;
 829
 830         if (off >= sizeof(compat_elf_gregset_t))
 831                 return 0;
 832
 833         ret = copy_regset_from_user(tsk, &user_aarch32_view,
 834                                     REGSET_COMPAT_GPR, off,
 835                                     sizeof(compat_ulong_t),
 836                                     &val);
 837         return ret;
 838 }
 839
 840 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 841
 842 /*
 843  * Convert a virtual register number into an index for a thread_info
 844  * breakpoint array. Breakpoints are identified using positive numbers
 845  * whilst watchpoints are negative. The registers are laid out as pairs
 846  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
 847  * Register 0 is reserved for describing resource information.
 848  */
 849 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
 850 {
 851         return (abs(num) - 1) >> 1;
 852 }
 853
 854 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
 855 {
 856         u8 num_brps, num_wrps, debug_arch, wp_len;
 857         u32 reg = 0;
 858
 859         num_brps        = hw_breakpoint_slots(TYPE_INST);
 860         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
 861
 862         debug_arch      = debug_monitors_arch();
 863         wp_len          = 8;
 864         reg             |= debug_arch;
 865         reg             <<= 8;
 866         reg             |= wp_len;
 867         reg             <<= 8;
 868         reg             |= num_wrps;
 869         reg             <<= 8;
 870         reg             |= num_brps;
 871
 872         *kdata = reg;
 873         return 0;
 874 }
 875
 876 static int compat_ptrace_hbp_get(unsigned int note_type,
 877                                  struct task_struct *tsk,
 878                                  compat_long_t num,
 879                                  u32 *kdata)
 880 {
 881         u64 addr = 0;
 882         u32 ctrl = 0;
 883
 884         int err, idx = compat_ptrace_hbp_num_to_idx(num);;
 885
 886         if (num & 1) {
 887                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
 888                 *kdata = (u32)addr;
 889         } else {
 890                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
 891                 *kdata = ctrl;
 892         }
 893
 894         return err;
 895 }
 896
 897 static int compat_ptrace_hbp_set(unsigned int note_type,
 898                                  struct task_struct *tsk,
 899                                  compat_long_t num,
 900                                  u32 *kdata)
 901 {
 902         u64 addr;
 903         u32 ctrl;
 904
 905         int err, idx = compat_ptrace_hbp_num_to_idx(num);
 906
 907         if (num & 1) {
 908                 addr = *kdata;
 909                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
 910         } else {
 911                 ctrl = *kdata;
 912                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
 913         }
 914
 915         return err;
 916 }
 917
 918 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
 919                                     compat_ulong_t __user *data)
 920 {
 921         int ret;
 922         u32 kdata;
 923         mm_segment_t old_fs = get_fs();
 924
 925         set_fs(KERNEL_DS);
 926         /* Watchpoint */
 927         if (num < 0) {
 928                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
 929         /* Resource info */
 930         } else if (num == 0) {
 931                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
 932         /* Breakpoint */
 933         } else {
 934                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
 935         }
 936         set_fs(old_fs);
 937
 938         if (!ret)
 939                 ret = put_user(kdata, data);
 940
 941         return ret;
 942 }
 943
 944 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
 945                                     compat_ulong_t __user *data)
 946 {
 947         int ret;
 948         u32 kdata = 0;
 949         mm_segment_t old_fs = get_fs();
 950
 951         if (num == 0)
 952                 return 0;
 953
 954         ret = get_user(kdata, data);
 955         if (ret)
 956                 return ret;
 957
 958         set_fs(KERNEL_DS);
 959         if (num < 0)
 960                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
 961         else
 962                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
 963         set_fs(old_fs);
 964
 965         return ret;
 966 }
 967 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 968
 969 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 970                         compat_ulong_t caddr, compat_ulong_t cdata)
 971 {
 972         unsigned long addr = caddr;
 973         unsigned long data = cdata;
 974         void __user *datap = compat_ptr(data);
 975         int ret;
 976
 977         switch (request) {
 978                 case PTRACE_PEEKUSR:
 979                         ret = compat_ptrace_read_user(child, addr, datap);
 980                         break;
 981
 982                 case PTRACE_POKEUSR:
 983                         ret = compat_ptrace_write_user(child, addr, data);
 984                         break;
 985
 986                 case COMPAT_PTRACE_GETREGS:
 987                         ret = copy_regset_to_user(child,
 988                                                   &user_aarch32_view,
 989                                                   REGSET_COMPAT_GPR,
 990                                                   0, sizeof(compat_elf_gregset_t),
 991                                                   datap);
 992                         break;
 993
 994                 case COMPAT_PTRACE_SETREGS:
 995                         ret = copy_regset_from_user(child,
 996                                                     &user_aarch32_view,
 997                                                     REGSET_COMPAT_GPR,
 998                                                     0, sizeof(compat_elf_gregset_t),
 999                                                     datap);
1000                         break;
1001
1002                 case COMPAT_PTRACE_GET_THREAD_AREA:
1003                         ret = put_user((compat_ulong_t)child->thread.tp_value,
1004                                        (compat_ulong_t __user *)datap);
1005                         break;
1006
1007                 case COMPAT_PTRACE_SET_SYSCALL:
1008                         task_pt_regs(child)->syscallno = data;
1009                         ret = 0;
1010                         break;
1011
1012                 case COMPAT_PTRACE_GETVFPREGS:
1013                         ret = copy_regset_to_user(child,
1014                                                   &user_aarch32_view,
1015                                                   REGSET_COMPAT_VFP,
1016                                                   0, VFP_STATE_SIZE,
1017                                                   datap);
1018                         break;
1019
1020                 case COMPAT_PTRACE_SETVFPREGS:
1021                         ret = copy_regset_from_user(child,
1022                                                     &user_aarch32_view,
1023                                                     REGSET_COMPAT_VFP,
1024                                                     0, VFP_STATE_SIZE,
1025                                                     datap);
1026                         break;
1027
1028 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1029                 case COMPAT_PTRACE_GETHBPREGS:
1030                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1031                         break;
1032
1033                 case COMPAT_PTRACE_SETHBPREGS:
1034                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1035                         break;
1036 #endif
1037
1038                 default:
1039                         ret = compat_ptrace_request(child, request, addr,
1040                                                     data);
1041                         break;
1042         }
1043
1044         return ret;
1045 }
1046 #endif /* CONFIG_COMPAT */
1047
1048 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1049 {
1050 #ifdef CONFIG_COMPAT
1051         if (is_compat_thread(task_thread_info(task)))
1052                 return &user_aarch32_view;
1053 #endif
1054         return &user_aarch64_view;
1055 }
1056
1057 long arch_ptrace(struct task_struct *child, long request,
1058                  unsigned long addr, unsigned long data)
1059 {
1060         return ptrace_request(child, request, addr, data);
1061 }
1062
1063 asmlinkage int syscall_trace(int dir, struct pt_regs *regs)
1064 {
1065         unsigned long saved_reg;
1066
1067         if (!test_thread_flag(TIF_SYSCALL_TRACE))
1068                 return regs->syscallno;
1069
1070         if (is_compat_task()) {
1071                 /* AArch32 uses ip (r12) for scratch */
1072                 saved_reg = regs->regs[12];
1073                 regs->regs[12] = dir;
1074         } else {
1075                 /*
1076                  * Save X7. X7 is used to denote syscall entry/exit:
1077                  *   X7 = 0 -> entry, = 1 -> exit
1078                  */
1079                 saved_reg = regs->regs[7];
1080                 regs->regs[7] = dir;
1081         }
1082
1083         if (dir)
1084                 tracehook_report_syscall_exit(regs, 0);
1085         else if (tracehook_report_syscall_entry(regs))
1086                 regs->syscallno = ~0UL;
1087
1088         if (is_compat_task())
1089                 regs->regs[12] = saved_reg;
1090         else
1091                 regs->regs[7] = saved_reg;
1092
1093         return regs->syscallno;
1094 }