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         attr->disabled = disabled;
 218         if (disabled)
 219                 return 0;
 220
 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         attr->bp_len    = len;
 239         attr->bp_type   = type;
 240
 241         return 0;
 242 }
 243
 244 static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info)
 245 {
 246         u8 num;
 247         u32 reg = 0;
 248
 249         switch (note_type) {
 250         case NT_ARM_HW_BREAK:
 251                 num = hw_breakpoint_slots(TYPE_INST);
 252                 break;
 253         case NT_ARM_HW_WATCH:
 254                 num = hw_breakpoint_slots(TYPE_DATA);
 255                 break;
 256         default:
 257                 return -EINVAL;
 258         }
 259
 260         reg |= debug_monitors_arch();
 261         reg <<= 8;
 262         reg |= num;
 263
 264         *info = reg;
 265         return 0;
 266 }
 267
 268 static int ptrace_hbp_get_ctrl(unsigned int note_type,
 269                                struct task_struct *tsk,
 270                                unsigned long idx,
 271                                u32 *ctrl)
 272 {
 273         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 274
 275         if (IS_ERR(bp))
 276                 return PTR_ERR(bp);
 277
 278         *ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0;
 279         return 0;
 280 }
 281
 282 static int ptrace_hbp_get_addr(unsigned int note_type,
 283                                struct task_struct *tsk,
 284                                unsigned long idx,
 285                                u64 *addr)
 286 {
 287         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 288
 289         if (IS_ERR(bp))
 290                 return PTR_ERR(bp);
 291
 292         *addr = bp ? bp->attr.bp_addr : 0;
 293         return 0;
 294 }
 295
 296 static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type,
 297                                                         struct task_struct *tsk,
 298                                                         unsigned long idx)
 299 {
 300         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 301
 302         if (!bp)
 303                 bp = ptrace_hbp_create(note_type, tsk, idx);
 304
 305         return bp;
 306 }
 307
 308 static int ptrace_hbp_set_ctrl(unsigned int note_type,
 309                                struct task_struct *tsk,
 310                                unsigned long idx,
 311                                u32 uctrl)
 312 {
 313         int err;
 314         struct perf_event *bp;
 315         struct perf_event_attr attr;
 316         struct arch_hw_breakpoint_ctrl ctrl;
 317
 318         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 319         if (IS_ERR(bp)) {
 320                 err = PTR_ERR(bp);
 321                 return err;
 322         }
 323
 324         attr = bp->attr;
 325         decode_ctrl_reg(uctrl, &ctrl);
 326         err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
 327         if (err)
 328                 return err;
 329
 330         return modify_user_hw_breakpoint(bp, &attr);
 331 }
 332
 333 static int ptrace_hbp_set_addr(unsigned int note_type,
 334                                struct task_struct *tsk,
 335                                unsigned long idx,
 336                                u64 addr)
 337 {
 338         int err;
 339         struct perf_event *bp;
 340         struct perf_event_attr attr;
 341
 342         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 343         if (IS_ERR(bp)) {
 344                 err = PTR_ERR(bp);
 345                 return err;
 346         }
 347
 348         attr = bp->attr;
 349         attr.bp_addr = addr;
 350         err = modify_user_hw_breakpoint(bp, &attr);
 351         return err;
 352 }
 353
 354 #define PTRACE_HBP_ADDR_SZ      sizeof(u64)
 355 #define PTRACE_HBP_CTRL_SZ      sizeof(u32)
 356 #define PTRACE_HBP_PAD_SZ       sizeof(u32)
 357
 358 static int hw_break_get(struct task_struct *target,
 359                         const struct user_regset *regset,
 360                         unsigned int pos, unsigned int count,
 361                         void *kbuf, void __user *ubuf)
 362 {
 363         unsigned int note_type = regset->core_note_type;
 364         int ret, idx = 0, offset, limit;
 365         u32 info, ctrl;
 366         u64 addr;
 367
 368         /* Resource info */
 369         ret = ptrace_hbp_get_resource_info(note_type, &info);
 370         if (ret)
 371                 return ret;
 372
 373         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0,
 374                                   sizeof(info));
 375         if (ret)
 376                 return ret;
 377
 378         /* Pad */
 379         offset = offsetof(struct user_hwdebug_state, pad);
 380         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, offset,
 381                                        offset + PTRACE_HBP_PAD_SZ);
 382         if (ret)
 383                 return ret;
 384
 385         /* (address, ctrl) registers */
 386         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 387         limit = regset->n * regset->size;
 388         while (count && offset < limit) {
 389                 ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
 390                 if (ret)
 391                         return ret;
 392                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr,
 393                                           offset, offset + PTRACE_HBP_ADDR_SZ);
 394                 if (ret)
 395                         return ret;
 396                 offset += PTRACE_HBP_ADDR_SZ;
 397
 398                 ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
 399                 if (ret)
 400                         return ret;
 401                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl,
 402                                           offset, offset + PTRACE_HBP_CTRL_SZ);
 403                 if (ret)
 404                         return ret;
 405                 offset += PTRACE_HBP_CTRL_SZ;
 406
 407                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 408                                                offset,
 409                                                offset + PTRACE_HBP_PAD_SZ);
 410                 if (ret)
 411                         return ret;
 412                 offset += PTRACE_HBP_PAD_SZ;
 413                 idx++;
 414         }
 415
 416         return 0;
 417 }
 418
 419 static int hw_break_set(struct task_struct *target,
 420                         const struct user_regset *regset,
 421                         unsigned int pos, unsigned int count,
 422                         const void *kbuf, const void __user *ubuf)
 423 {
 424         unsigned int note_type = regset->core_note_type;
 425         int ret, idx = 0, offset, limit;
 426         u32 ctrl;
 427         u64 addr;
 428
 429         /* Resource info and pad */
 430         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 431         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset);
 432         if (ret)
 433                 return ret;
 434
 435         /* (address, ctrl) registers */
 436         limit = regset->n * regset->size;
 437         while (count && offset < limit) {
 438                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
 439                                          offset, offset + PTRACE_HBP_ADDR_SZ);
 440                 if (ret)
 441                         return ret;
 442                 ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
 443                 if (ret)
 444                         return ret;
 445                 offset += PTRACE_HBP_ADDR_SZ;
 446
 447                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
 448                                          offset, offset + PTRACE_HBP_CTRL_SZ);
 449                 if (ret)
 450                         return ret;
 451                 ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
 452                 if (ret)
 453                         return ret;
 454                 offset += PTRACE_HBP_CTRL_SZ;
 455
 456                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 457                                                 offset,
 458                                                 offset + PTRACE_HBP_PAD_SZ);
 459                 if (ret)
 460                         return ret;
 461                 offset += PTRACE_HBP_PAD_SZ;
 462                 idx++;
 463         }
 464
 465         return 0;
 466 }
 467 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 468
 469 static int gpr_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         struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
 475         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 476 }
 477
 478 static int gpr_set(struct task_struct *target, const struct user_regset *regset,
 479                    unsigned int pos, unsigned int count,
 480                    const void *kbuf, const void __user *ubuf)
 481 {
 482         int ret;
 483         struct user_pt_regs newregs;
 484
 485         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
 486         if (ret)
 487                 return ret;
 488
 489         if (!valid_user_regs(&newregs))
 490                 return -EINVAL;
 491
 492         task_pt_regs(target)->user_regs = newregs;
 493         return 0;
 494 }
 495
 496 /*
 497  * TODO: update fp accessors for lazy context switching (sync/flush hwstate)
 498  */
 499 static int fpr_get(struct task_struct *target, const struct user_regset *regset,
 500                    unsigned int pos, unsigned int count,
 501                    void *kbuf, void __user *ubuf)
 502 {
 503         struct user_fpsimd_state *uregs;
 504         uregs = &target->thread.fpsimd_state.user_fpsimd;
 505         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 506 }
 507
 508 static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 509                    unsigned int pos, unsigned int count,
 510                    const void *kbuf, const void __user *ubuf)
 511 {
 512         int ret;
 513         struct user_fpsimd_state newstate;
 514
 515         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1);
 516         if (ret)
 517                 return ret;
 518
 519         target->thread.fpsimd_state.user_fpsimd = newstate;
 520         return ret;
 521 }
 522
 523 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 524                    unsigned int pos, unsigned int count,
 525                    void *kbuf, void __user *ubuf)
 526 {
 527         unsigned long *tls = &target->thread.tp_value;
 528         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
 529 }
 530
 531 static int tls_set(struct task_struct *target, const struct user_regset *regset,
 532                    unsigned int pos, unsigned int count,
 533                    const void *kbuf, const void __user *ubuf)
 534 {
 535         int ret;
 536         unsigned long tls;
 537
 538         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 539         if (ret)
 540                 return ret;
 541
 542         target->thread.tp_value = tls;
 543         return ret;
 544 }
 545
 546 enum aarch64_regset {
 547         REGSET_GPR,
 548         REGSET_FPR,
 549         REGSET_TLS,
 550 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 551         REGSET_HW_BREAK,
 552         REGSET_HW_WATCH,
 553 #endif
 554 };
 555
 556 static const struct user_regset aarch64_regsets[] = {
 557         [REGSET_GPR] = {
 558                 .core_note_type = NT_PRSTATUS,
 559                 .n = sizeof(struct user_pt_regs) / sizeof(u64),
 560                 .size = sizeof(u64),
 561                 .align = sizeof(u64),
 562                 .get = gpr_get,
 563                 .set = gpr_set
 564         },
 565         [REGSET_FPR] = {
 566                 .core_note_type = NT_PRFPREG,
 567                 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
 568                 /*
 569                  * We pretend we have 32-bit registers because the fpsr and
 570                  * fpcr are 32-bits wide.
 571                  */
 572                 .size = sizeof(u32),
 573                 .align = sizeof(u32),
 574                 .get = fpr_get,
 575                 .set = fpr_set
 576         },
 577         [REGSET_TLS] = {
 578                 .core_note_type = NT_ARM_TLS,
 579                 .n = 1,
 580                 .size = sizeof(void *),
 581                 .align = sizeof(void *),
 582                 .get = tls_get,
 583                 .set = tls_set,
 584         },
 585 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 586         [REGSET_HW_BREAK] = {
 587                 .core_note_type = NT_ARM_HW_BREAK,
 588                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 589                 .size = sizeof(u32),
 590                 .align = sizeof(u32),
 591                 .get = hw_break_get,
 592                 .set = hw_break_set,
 593         },
 594         [REGSET_HW_WATCH] = {
 595                 .core_note_type = NT_ARM_HW_WATCH,
 596                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 597                 .size = sizeof(u32),
 598                 .align = sizeof(u32),
 599                 .get = hw_break_get,
 600                 .set = hw_break_set,
 601         },
 602 #endif
 603 };
 604
 605 static const struct user_regset_view user_aarch64_view = {
 606         .name = "aarch64", .e_machine = EM_AARCH64,
 607         .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
 608 };
 609
 610 #ifdef CONFIG_COMPAT
 611 #include <linux/compat.h>
 612
 613 enum compat_regset {
 614         REGSET_COMPAT_GPR,
 615         REGSET_COMPAT_VFP,
 616 };
 617
 618 static int compat_gpr_get(struct task_struct *target,
 619                           const struct user_regset *regset,
 620                           unsigned int pos, unsigned int count,
 621                           void *kbuf, void __user *ubuf)
 622 {
 623         int ret = 0;
 624         unsigned int i, start, num_regs;
 625
 626         /* Calculate the number of AArch32 registers contained in count */
 627         num_regs = count / regset->size;
 628
 629         /* Convert pos into an register number */
 630         start = pos / regset->size;
 631
 632         if (start + num_regs > regset->n)
 633                 return -EIO;
 634
 635         for (i = 0; i < num_regs; ++i) {
 636                 unsigned int idx = start + i;
 637                 compat_ulong_t reg;
 638
 639                 switch (idx) {
 640                 case 15:
 641                         reg = task_pt_regs(target)->pc;
 642                         break;
 643                 case 16:
 644                         reg = task_pt_regs(target)->pstate;
 645                         break;
 646                 case 17:
 647                         reg = task_pt_regs(target)->orig_x0;
 648                         break;
 649                 default:
 650                         reg = task_pt_regs(target)->regs[idx];
 651                 }
 652
 653                 ret = copy_to_user(ubuf, &reg, sizeof(reg));
 654                 if (ret)
 655                         break;
 656
 657                 ubuf += sizeof(reg);
 658         }
 659
 660         return ret;
 661 }
 662
 663 static int compat_gpr_set(struct task_struct *target,
 664                           const struct user_regset *regset,
 665                           unsigned int pos, unsigned int count,
 666                           const void *kbuf, const void __user *ubuf)
 667 {
 668         struct pt_regs newregs;
 669         int ret = 0;
 670         unsigned int i, start, num_regs;
 671
 672         /* Calculate the number of AArch32 registers contained in count */
 673         num_regs = count / regset->size;
 674
 675         /* Convert pos into an register number */
 676         start = pos / regset->size;
 677
 678         if (start + num_regs > regset->n)
 679                 return -EIO;
 680
 681         newregs = *task_pt_regs(target);
 682
 683         for (i = 0; i < num_regs; ++i) {
 684                 unsigned int idx = start + i;
 685                 compat_ulong_t reg;
 686
 687                 ret = copy_from_user(&reg, ubuf, sizeof(reg));
 688                 if (ret)
 689                         return ret;
 690
 691                 ubuf += sizeof(reg);
 692
 693                 switch (idx) {
 694                 case 15:
 695                         newregs.pc = reg;
 696                         break;
 697                 case 16:
 698                         newregs.pstate = reg;
 699                         break;
 700                 case 17:
 701                         newregs.orig_x0 = reg;
 702                         break;
 703                 default:
 704                         newregs.regs[idx] = reg;
 705                 }
 706
 707         }
 708
 709         if (valid_user_regs(&newregs.user_regs))
 710                 *task_pt_regs(target) = newregs;
 711         else
 712                 ret = -EINVAL;
 713
 714         return ret;
 715 }
 716
 717 static int compat_vfp_get(struct task_struct *target,
 718                           const struct user_regset *regset,
 719                           unsigned int pos, unsigned int count,
 720                           void *kbuf, void __user *ubuf)
 721 {
 722         struct user_fpsimd_state *uregs;
 723         compat_ulong_t fpscr;
 724         int ret;
 725
 726         uregs = &target->thread.fpsimd_state.user_fpsimd;
 727
 728         /*
 729          * The VFP registers are packed into the fpsimd_state, so they all sit
 730          * nicely together for us. We just need to create the fpscr separately.
 731          */
 732         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
 733                                   VFP_STATE_SIZE - sizeof(compat_ulong_t));
 734
 735         if (count && !ret) {
 736                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
 737                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
 738                 ret = put_user(fpscr, (compat_ulong_t *)ubuf);
 739         }
 740
 741         return ret;
 742 }
 743
 744 static int compat_vfp_set(struct task_struct *target,
 745                           const struct user_regset *regset,
 746                           unsigned int pos, unsigned int count,
 747                           const void *kbuf, const void __user *ubuf)
 748 {
 749         struct user_fpsimd_state *uregs;
 750         compat_ulong_t fpscr;
 751         int ret;
 752
 753         if (pos + count > VFP_STATE_SIZE)
 754                 return -EIO;
 755
 756         uregs = &target->thread.fpsimd_state.user_fpsimd;
 757
 758         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
 759                                  VFP_STATE_SIZE - sizeof(compat_ulong_t));
 760
 761         if (count && !ret) {
 762                 ret = get_user(fpscr, (compat_ulong_t *)ubuf);
 763                 uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
 764                 uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
 765         }
 766
 767         return ret;
 768 }
 769
 770 static const struct user_regset aarch32_regsets[] = {
 771         [REGSET_COMPAT_GPR] = {
 772                 .core_note_type = NT_PRSTATUS,
 773                 .n = COMPAT_ELF_NGREG,
 774                 .size = sizeof(compat_elf_greg_t),
 775                 .align = sizeof(compat_elf_greg_t),
 776                 .get = compat_gpr_get,
 777                 .set = compat_gpr_set
 778         },
 779         [REGSET_COMPAT_VFP] = {
 780                 .core_note_type = NT_ARM_VFP,
 781                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
 782                 .size = sizeof(compat_ulong_t),
 783                 .align = sizeof(compat_ulong_t),
 784                 .get = compat_vfp_get,
 785                 .set = compat_vfp_set
 786         },
 787 };
 788
 789 static const struct user_regset_view user_aarch32_view = {
 790         .name = "aarch32", .e_machine = EM_ARM,
 791         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
 792 };
 793
 794 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
 795                                    compat_ulong_t __user *ret)
 796 {
 797         compat_ulong_t tmp;
 798
 799         if (off & 3)
 800                 return -EIO;
 801
 802         if (off == COMPAT_PT_TEXT_ADDR)
 803                 tmp = tsk->mm->start_code;
 804         else if (off == COMPAT_PT_DATA_ADDR)
 805                 tmp = tsk->mm->start_data;
 806         else if (off == COMPAT_PT_TEXT_END_ADDR)
 807                 tmp = tsk->mm->end_code;
 808         else if (off < sizeof(compat_elf_gregset_t))
 809                 return copy_regset_to_user(tsk, &user_aarch32_view,
 810                                            REGSET_COMPAT_GPR, off,
 811                                            sizeof(compat_ulong_t), ret);
 812         else if (off >= COMPAT_USER_SZ)
 813                 return -EIO;
 814         else
 815                 tmp = 0;
 816
 817         return put_user(tmp, ret);
 818 }
 819
 820 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
 821                                     compat_ulong_t val)
 822 {
 823         int ret;
 824
 825         if (off & 3 || off >= COMPAT_USER_SZ)
 826                 return -EIO;
 827
 828         if (off >= sizeof(compat_elf_gregset_t))
 829                 return 0;
 830
 831         ret = copy_regset_from_user(tsk, &user_aarch32_view,
 832                                     REGSET_COMPAT_GPR, off,
 833                                     sizeof(compat_ulong_t),
 834                                     &val);
 835         return ret;
 836 }
 837
 838 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 839
 840 /*
 841  * Convert a virtual register number into an index for a thread_info
 842  * breakpoint array. Breakpoints are identified using positive numbers
 843  * whilst watchpoints are negative. The registers are laid out as pairs
 844  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
 845  * Register 0 is reserved for describing resource information.
 846  */
 847 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
 848 {
 849         return (abs(num) - 1) >> 1;
 850 }
 851
 852 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
 853 {
 854         u8 num_brps, num_wrps, debug_arch, wp_len;
 855         u32 reg = 0;
 856
 857         num_brps        = hw_breakpoint_slots(TYPE_INST);
 858         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
 859
 860         debug_arch      = debug_monitors_arch();
 861         wp_len          = 8;
 862         reg             |= debug_arch;
 863         reg             <<= 8;
 864         reg             |= wp_len;
 865         reg             <<= 8;
 866         reg             |= num_wrps;
 867         reg             <<= 8;
 868         reg             |= num_brps;
 869
 870         *kdata = reg;
 871         return 0;
 872 }
 873
 874 static int compat_ptrace_hbp_get(unsigned int note_type,
 875                                  struct task_struct *tsk,
 876                                  compat_long_t num,
 877                                  u32 *kdata)
 878 {
 879         u64 addr = 0;
 880         u32 ctrl = 0;
 881
 882         int err, idx = compat_ptrace_hbp_num_to_idx(num);;
 883
 884         if (num & 1) {
 885                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
 886                 *kdata = (u32)addr;
 887         } else {
 888                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
 889                 *kdata = ctrl;
 890         }
 891
 892         return err;
 893 }
 894
 895 static int compat_ptrace_hbp_set(unsigned int note_type,
 896                                  struct task_struct *tsk,
 897                                  compat_long_t num,
 898                                  u32 *kdata)
 899 {
 900         u64 addr;
 901         u32 ctrl;
 902
 903         int err, idx = compat_ptrace_hbp_num_to_idx(num);
 904
 905         if (num & 1) {
 906                 addr = *kdata;
 907                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
 908         } else {
 909                 ctrl = *kdata;
 910                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
 911         }
 912
 913         return err;
 914 }
 915
 916 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
 917                                     compat_ulong_t __user *data)
 918 {
 919         int ret;
 920         u32 kdata;
 921         mm_segment_t old_fs = get_fs();
 922
 923         set_fs(KERNEL_DS);
 924         /* Watchpoint */
 925         if (num < 0) {
 926                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
 927         /* Resource info */
 928         } else if (num == 0) {
 929                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
 930         /* Breakpoint */
 931         } else {
 932                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
 933         }
 934         set_fs(old_fs);
 935
 936         if (!ret)
 937                 ret = put_user(kdata, data);
 938
 939         return ret;
 940 }
 941
 942 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
 943                                     compat_ulong_t __user *data)
 944 {
 945         int ret;
 946         u32 kdata = 0;
 947         mm_segment_t old_fs = get_fs();
 948
 949         if (num == 0)
 950                 return 0;
 951
 952         ret = get_user(kdata, data);
 953         if (ret)
 954                 return ret;
 955
 956         set_fs(KERNEL_DS);
 957         if (num < 0)
 958                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
 959         else
 960                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
 961         set_fs(old_fs);
 962
 963         return ret;
 964 }
 965 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 966
 967 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 968                         compat_ulong_t caddr, compat_ulong_t cdata)
 969 {
 970         unsigned long addr = caddr;
 971         unsigned long data = cdata;
 972         void __user *datap = compat_ptr(data);
 973         int ret;
 974
 975         switch (request) {
 976                 case PTRACE_PEEKUSR:
 977                         ret = compat_ptrace_read_user(child, addr, datap);
 978                         break;
 979
 980                 case PTRACE_POKEUSR:
 981                         ret = compat_ptrace_write_user(child, addr, data);
 982                         break;
 983
 984                 case COMPAT_PTRACE_GETREGS:
 985                         ret = copy_regset_to_user(child,
 986                                                   &user_aarch32_view,
 987                                                   REGSET_COMPAT_GPR,
 988                                                   0, sizeof(compat_elf_gregset_t),
 989                                                   datap);
 990                         break;
 991
 992                 case COMPAT_PTRACE_SETREGS:
 993                         ret = copy_regset_from_user(child,
 994                                                     &user_aarch32_view,
 995                                                     REGSET_COMPAT_GPR,
 996                                                     0, sizeof(compat_elf_gregset_t),
 997                                                     datap);
 998                         break;
 999
1000                 case COMPAT_PTRACE_GET_THREAD_AREA:
1001                         ret = put_user((compat_ulong_t)child->thread.tp_value,
1002                                        (compat_ulong_t __user *)datap);
1003                         break;
1004
1005                 case COMPAT_PTRACE_SET_SYSCALL:
1006                         task_pt_regs(child)->syscallno = data;
1007                         ret = 0;
1008                         break;
1009
1010                 case COMPAT_PTRACE_GETVFPREGS:
1011                         ret = copy_regset_to_user(child,
1012                                                   &user_aarch32_view,
1013                                                   REGSET_COMPAT_VFP,
1014                                                   0, VFP_STATE_SIZE,
1015                                                   datap);
1016                         break;
1017
1018                 case COMPAT_PTRACE_SETVFPREGS:
1019                         ret = copy_regset_from_user(child,
1020                                                     &user_aarch32_view,
1021                                                     REGSET_COMPAT_VFP,
1022                                                     0, VFP_STATE_SIZE,
1023                                                     datap);
1024                         break;
1025
1026 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1027                 case COMPAT_PTRACE_GETHBPREGS:
1028                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1029                         break;
1030
1031                 case COMPAT_PTRACE_SETHBPREGS:
1032                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1033                         break;
1034 #endif
1035
1036                 default:
1037                         ret = compat_ptrace_request(child, request, addr,
1038                                                     data);
1039                         break;
1040         }
1041
1042         return ret;
1043 }
1044 #endif /* CONFIG_COMPAT */
1045
1046 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1047 {
1048 #ifdef CONFIG_COMPAT
1049         if (is_compat_thread(task_thread_info(task)))
1050                 return &user_aarch32_view;
1051 #endif
1052         return &user_aarch64_view;
1053 }
1054
1055 long arch_ptrace(struct task_struct *child, long request,
1056                  unsigned long addr, unsigned long data)
1057 {
1058         return ptrace_request(child, request, addr, data);
1059 }
1060
1061 asmlinkage int syscall_trace(int dir, struct pt_regs *regs)
1062 {
1063         unsigned long saved_reg;
1064
1065         if (!test_thread_flag(TIF_SYSCALL_TRACE))
1066                 return regs->syscallno;
1067
1068         if (is_compat_task()) {
1069                 /* AArch32 uses ip (r12) for scratch */
1070                 saved_reg = regs->regs[12];
1071                 regs->regs[12] = dir;
1072         } else {
1073                 /*
1074                  * Save X7. X7 is used to denote syscall entry/exit:
1075                  *   X7 = 0 -> entry, = 1 -> exit
1076                  */
1077                 saved_reg = regs->regs[7];
1078                 regs->regs[7] = dir;
1079         }
1080
1081         if (dir)
1082                 tracehook_report_syscall_exit(regs, 0);
1083         else if (tracehook_report_syscall_entry(regs))
1084                 regs->syscallno = ~0UL;
1085
1086         if (is_compat_task())
1087                 regs->regs[12] = saved_reg;
1088         else
1089                 regs->regs[7] = saved_reg;
1090
1091         return regs->syscallno;
1092 }