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                 void *reg;
 638
 639                 switch (idx) {
 640                 case 15:
 641                         reg = (void *)&task_pt_regs(target)->pc;
 642                         break;
 643                 case 16:
 644                         reg = (void *)&task_pt_regs(target)->pstate;
 645                         break;
 646                 case 17:
 647                         reg = (void *)&task_pt_regs(target)->orig_x0;
 648                         break;
 649                 default:
 650                         reg = (void *)&task_pt_regs(target)->regs[idx];
 651                 }
 652
 653                 if (kbuf) {
 654                         memcpy(kbuf, &reg, sizeof(reg));
 655                         kbuf += sizeof(reg);
 656                 } else {
 657                         ret = copy_to_user(ubuf, &reg, sizeof(reg));
 658                         if (ret)
 659                                 break;
 660
 661                         ubuf += sizeof(reg);
 662                 }
 663         }
 664
 665         return ret;
 666 }
 667
 668 static int compat_gpr_set(struct task_struct *target,
 669                           const struct user_regset *regset,
 670                           unsigned int pos, unsigned int count,
 671                           const void *kbuf, const void __user *ubuf)
 672 {
 673         struct pt_regs newregs;
 674         int ret = 0;
 675         unsigned int i, start, num_regs;
 676
 677         /* Calculate the number of AArch32 registers contained in count */
 678         num_regs = count / regset->size;
 679
 680         /* Convert pos into an register number */
 681         start = pos / regset->size;
 682
 683         if (start + num_regs > regset->n)
 684                 return -EIO;
 685
 686         newregs = *task_pt_regs(target);
 687
 688         for (i = 0; i < num_regs; ++i) {
 689                 unsigned int idx = start + i;
 690                 compat_ulong_t reg;
 691
 692                 if (kbuf) {
 693                         memcpy(&reg, kbuf, sizeof(reg));
 694                         kbuf += sizeof(reg);
 695                 } else {
 696                         ret = copy_from_user(&reg, ubuf, sizeof(reg));
 697                         if (ret)
 698                                 return ret;
 699
 700                         ubuf += sizeof(reg);
 701                 }
 702
 703                 switch (idx) {
 704                 case 15:
 705                         reg = (void *)&newregs.pc;
 706                         break;
 707                 case 16:
 708                         reg = (void *)&newregs.pstate;
 709                         break;
 710                 case 17:
 711                         reg = (void *)&newregs.orig_x0;
 712                         break;
 713                 default:
 714                         reg = (void *)&newregs.regs[idx];
 715                 }
 716
 717                 ret = copy_from_user(reg, ubuf, sizeof(compat_ulong_t));
 718
 719                 if (ret)
 720                         goto out;
 721                 else
 722                         ubuf += sizeof(compat_ulong_t);
 723         }
 724
 725         if (valid_user_regs(&newregs.user_regs))
 726                 *task_pt_regs(target) = newregs;
 727         else
 728                 ret = -EINVAL;
 729
 730 out:
 731         return ret;
 732 }
 733
 734 static int compat_vfp_get(struct task_struct *target,
 735                           const struct user_regset *regset,
 736                           unsigned int pos, unsigned int count,
 737                           void *kbuf, void __user *ubuf)
 738 {
 739         struct user_fpsimd_state *uregs;
 740         compat_ulong_t fpscr;
 741         int ret;
 742
 743         uregs = &target->thread.fpsimd_state.user_fpsimd;
 744
 745         /*
 746          * The VFP registers are packed into the fpsimd_state, so they all sit
 747          * nicely together for us. We just need to create the fpscr separately.
 748          */
 749         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
 750                                   VFP_STATE_SIZE - sizeof(compat_ulong_t));
 751
 752         if (count && !ret) {
 753                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
 754                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
 755                 ret = put_user(fpscr, (compat_ulong_t *)ubuf);
 756         }
 757
 758         return ret;
 759 }
 760
 761 static int compat_vfp_set(struct task_struct *target,
 762                           const struct user_regset *regset,
 763                           unsigned int pos, unsigned int count,
 764                           const void *kbuf, const void __user *ubuf)
 765 {
 766         struct user_fpsimd_state *uregs;
 767         compat_ulong_t fpscr;
 768         int ret;
 769
 770         if (pos + count > VFP_STATE_SIZE)
 771                 return -EIO;
 772
 773         uregs = &target->thread.fpsimd_state.user_fpsimd;
 774
 775         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
 776                                  VFP_STATE_SIZE - sizeof(compat_ulong_t));
 777
 778         if (count && !ret) {
 779                 ret = get_user(fpscr, (compat_ulong_t *)ubuf);
 780                 uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
 781                 uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
 782         }
 783
 784         return ret;
 785 }
 786
 787 static const struct user_regset aarch32_regsets[] = {
 788         [REGSET_COMPAT_GPR] = {
 789                 .core_note_type = NT_PRSTATUS,
 790                 .n = COMPAT_ELF_NGREG,
 791                 .size = sizeof(compat_elf_greg_t),
 792                 .align = sizeof(compat_elf_greg_t),
 793                 .get = compat_gpr_get,
 794                 .set = compat_gpr_set
 795         },
 796         [REGSET_COMPAT_VFP] = {
 797                 .core_note_type = NT_ARM_VFP,
 798                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
 799                 .size = sizeof(compat_ulong_t),
 800                 .align = sizeof(compat_ulong_t),
 801                 .get = compat_vfp_get,
 802                 .set = compat_vfp_set
 803         },
 804 };
 805
 806 static const struct user_regset_view user_aarch32_view = {
 807         .name = "aarch32", .e_machine = EM_ARM,
 808         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
 809 };
 810
 811 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
 812                                    compat_ulong_t __user *ret)
 813 {
 814         compat_ulong_t tmp;
 815
 816         if (off & 3)
 817                 return -EIO;
 818
 819         if (off == COMPAT_PT_TEXT_ADDR)
 820                 tmp = tsk->mm->start_code;
 821         else if (off == COMPAT_PT_DATA_ADDR)
 822                 tmp = tsk->mm->start_data;
 823         else if (off == COMPAT_PT_TEXT_END_ADDR)
 824                 tmp = tsk->mm->end_code;
 825         else if (off < sizeof(compat_elf_gregset_t))
 826                 return copy_regset_to_user(tsk, &user_aarch32_view,
 827                                            REGSET_COMPAT_GPR, off,
 828                                            sizeof(compat_ulong_t), ret);
 829         else if (off >= COMPAT_USER_SZ)
 830                 return -EIO;
 831         else
 832                 tmp = 0;
 833
 834         return put_user(tmp, ret);
 835 }
 836
 837 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
 838                                     compat_ulong_t val)
 839 {
 840         int ret;
 841         mm_segment_t old_fs = get_fs();
 842
 843         if (off & 3 || off >= COMPAT_USER_SZ)
 844                 return -EIO;
 845
 846         if (off >= sizeof(compat_elf_gregset_t))
 847                 return 0;
 848
 849         set_fs(KERNEL_DS);
 850         ret = copy_regset_from_user(tsk, &user_aarch32_view,
 851                                     REGSET_COMPAT_GPR, off,
 852                                     sizeof(compat_ulong_t),
 853                                     &val);
 854         set_fs(old_fs);
 855
 856         return ret;
 857 }
 858
 859 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 860
 861 /*
 862  * Convert a virtual register number into an index for a thread_info
 863  * breakpoint array. Breakpoints are identified using positive numbers
 864  * whilst watchpoints are negative. The registers are laid out as pairs
 865  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
 866  * Register 0 is reserved for describing resource information.
 867  */
 868 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
 869 {
 870         return (abs(num) - 1) >> 1;
 871 }
 872
 873 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
 874 {
 875         u8 num_brps, num_wrps, debug_arch, wp_len;
 876         u32 reg = 0;
 877
 878         num_brps        = hw_breakpoint_slots(TYPE_INST);
 879         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
 880
 881         debug_arch      = debug_monitors_arch();
 882         wp_len          = 8;
 883         reg             |= debug_arch;
 884         reg             <<= 8;
 885         reg             |= wp_len;
 886         reg             <<= 8;
 887         reg             |= num_wrps;
 888         reg             <<= 8;
 889         reg             |= num_brps;
 890
 891         *kdata = reg;
 892         return 0;
 893 }
 894
 895 static int compat_ptrace_hbp_get(unsigned int note_type,
 896                                  struct task_struct *tsk,
 897                                  compat_long_t num,
 898                                  u32 *kdata)
 899 {
 900         u64 addr = 0;
 901         u32 ctrl = 0;
 902
 903         int err, idx = compat_ptrace_hbp_num_to_idx(num);;
 904
 905         if (num & 1) {
 906                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
 907                 *kdata = (u32)addr;
 908         } else {
 909                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
 910                 *kdata = ctrl;
 911         }
 912
 913         return err;
 914 }
 915
 916 static int compat_ptrace_hbp_set(unsigned int note_type,
 917                                  struct task_struct *tsk,
 918                                  compat_long_t num,
 919                                  u32 *kdata)
 920 {
 921         u64 addr;
 922         u32 ctrl;
 923
 924         int err, idx = compat_ptrace_hbp_num_to_idx(num);
 925
 926         if (num & 1) {
 927                 addr = *kdata;
 928                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
 929         } else {
 930                 ctrl = *kdata;
 931                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
 932         }
 933
 934         return err;
 935 }
 936
 937 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
 938                                     compat_ulong_t __user *data)
 939 {
 940         int ret;
 941         u32 kdata;
 942         mm_segment_t old_fs = get_fs();
 943
 944         set_fs(KERNEL_DS);
 945         /* Watchpoint */
 946         if (num < 0) {
 947                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
 948         /* Resource info */
 949         } else if (num == 0) {
 950                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
 951         /* Breakpoint */
 952         } else {
 953                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
 954         }
 955         set_fs(old_fs);
 956
 957         if (!ret)
 958                 ret = put_user(kdata, data);
 959
 960         return ret;
 961 }
 962
 963 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
 964                                     compat_ulong_t __user *data)
 965 {
 966         int ret;
 967         u32 kdata = 0;
 968         mm_segment_t old_fs = get_fs();
 969
 970         if (num == 0)
 971                 return 0;
 972
 973         ret = get_user(kdata, data);
 974         if (ret)
 975                 return ret;
 976
 977         set_fs(KERNEL_DS);
 978         if (num < 0)
 979                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
 980         else
 981                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
 982         set_fs(old_fs);
 983
 984         return ret;
 985 }
 986 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 987
 988 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 989                         compat_ulong_t caddr, compat_ulong_t cdata)
 990 {
 991         unsigned long addr = caddr;
 992         unsigned long data = cdata;
 993         void __user *datap = compat_ptr(data);
 994         int ret;
 995
 996         switch (request) {
 997                 case PTRACE_PEEKUSR:
 998                         ret = compat_ptrace_read_user(child, addr, datap);
 999                         break;
1000
1001                 case PTRACE_POKEUSR:
1002                         ret = compat_ptrace_write_user(child, addr, data);
1003                         break;
1004
1005                 case COMPAT_PTRACE_GETREGS:
1006                         ret = copy_regset_to_user(child,
1007                                                   &user_aarch32_view,
1008                                                   REGSET_COMPAT_GPR,
1009                                                   0, sizeof(compat_elf_gregset_t),
1010                                                   datap);
1011                         break;
1012
1013                 case COMPAT_PTRACE_SETREGS:
1014                         ret = copy_regset_from_user(child,
1015                                                     &user_aarch32_view,
1016                                                     REGSET_COMPAT_GPR,
1017                                                     0, sizeof(compat_elf_gregset_t),
1018                                                     datap);
1019                         break;
1020
1021                 case COMPAT_PTRACE_GET_THREAD_AREA:
1022                         ret = put_user((compat_ulong_t)child->thread.tp_value,
1023                                        (compat_ulong_t __user *)datap);
1024                         break;
1025
1026                 case COMPAT_PTRACE_SET_SYSCALL:
1027                         task_pt_regs(child)->syscallno = data;
1028                         ret = 0;
1029                         break;
1030
1031                 case COMPAT_PTRACE_GETVFPREGS:
1032                         ret = copy_regset_to_user(child,
1033                                                   &user_aarch32_view,
1034                                                   REGSET_COMPAT_VFP,
1035                                                   0, VFP_STATE_SIZE,
1036                                                   datap);
1037                         break;
1038
1039                 case COMPAT_PTRACE_SETVFPREGS:
1040                         ret = copy_regset_from_user(child,
1041                                                     &user_aarch32_view,
1042                                                     REGSET_COMPAT_VFP,
1043                                                     0, VFP_STATE_SIZE,
1044                                                     datap);
1045                         break;
1046
1047 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1048                 case COMPAT_PTRACE_GETHBPREGS:
1049                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1050                         break;
1051
1052                 case COMPAT_PTRACE_SETHBPREGS:
1053                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1054                         break;
1055 #endif
1056
1057                 default:
1058                         ret = compat_ptrace_request(child, request, addr,
1059                                                     data);
1060                         break;
1061         }
1062
1063         return ret;
1064 }
1065 #endif /* CONFIG_COMPAT */
1066
1067 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1068 {
1069 #ifdef CONFIG_COMPAT
1070         if (is_compat_thread(task_thread_info(task)))
1071                 return &user_aarch32_view;
1072 #endif
1073         return &user_aarch64_view;
1074 }
1075
1076 long arch_ptrace(struct task_struct *child, long request,
1077                  unsigned long addr, unsigned long data)
1078 {
1079         return ptrace_request(child, request, addr, data);
1080 }
1081
1082 asmlinkage int syscall_trace(int dir, struct pt_regs *regs)
1083 {
1084         unsigned long saved_reg;
1085
1086         if (!test_thread_flag(TIF_SYSCALL_TRACE))
1087                 return regs->syscallno;
1088
1089         if (is_compat_task()) {
1090                 /* AArch32 uses ip (r12) for scratch */
1091                 saved_reg = regs->regs[12];
1092                 regs->regs[12] = dir;
1093         } else {
1094                 /*
1095                  * Save X7. X7 is used to denote syscall entry/exit:
1096                  *   X7 = 0 -> entry, = 1 -> exit
1097                  */
1098                 saved_reg = regs->regs[7];
1099                 regs->regs[7] = dir;
1100         }
1101
1102         if (dir)
1103                 tracehook_report_syscall_exit(regs, 0);
1104         else if (tracehook_report_syscall_entry(regs))
1105                 regs->syscallno = ~0UL;
1106
1107         if (is_compat_task())
1108                 regs->regs[12] = saved_reg;
1109         else
1110                 regs->regs[7] = saved_reg;
1111
1112         return regs->syscallno;
1113 }