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/audit.h>
  23 #include <linux/compat.h>
  24 #include <linux/kernel.h>
  25 #include <linux/sched.h>
  26 #include <linux/mm.h>
  27 #include <linux/smp.h>
  28 #include <linux/ptrace.h>
  29 #include <linux/user.h>
  30 #include <linux/seccomp.h>
  31 #include <linux/security.h>
  32 #include <linux/init.h>
  33 #include <linux/signal.h>
  34 #include <linux/uaccess.h>
  35 #include <linux/perf_event.h>
  36 #include <linux/hw_breakpoint.h>
  37 #include <linux/regset.h>
  38 #include <linux/tracehook.h>
  39 #include <linux/elf.h>
  40
  41 #include <asm/compat.h>
  42 #include <asm/debug-monitors.h>
  43 #include <asm/pgtable.h>
  44 #include <asm/syscall.h>
  45 #include <asm/traps.h>
  46 #include <asm/system_misc.h>
  47
  48 #define CREATE_TRACE_POINTS
  49 #include <trace/events/syscalls.h>
  50
  51 /*
  52  * TODO: does not yet catch signals sent when the child dies.
  53  * in exit.c or in signal.c.
  54  */
  55
  56 /*
  57  * Called by kernel/ptrace.c when detaching..
  58  */
  59 void ptrace_disable(struct task_struct *child)
  60 {
  61 }
  62
  63 #ifdef CONFIG_HAVE_HW_BREAKPOINT
  64 /*
  65  * Handle hitting a HW-breakpoint.
  66  */
  67 static void ptrace_hbptriggered(struct perf_event *bp,
  68                                 struct perf_sample_data *data,
  69                                 struct pt_regs *regs)
  70 {
  71         struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
  72         siginfo_t info = {
  73                 .si_signo       = SIGTRAP,
  74                 .si_errno       = 0,
  75                 .si_code        = TRAP_HWBKPT,
  76                 .si_addr        = (void __user *)(bkpt->trigger),
  77         };
  78
  79 #ifdef CONFIG_COMPAT
  80         int i;
  81
  82         if (!is_compat_task())
  83                 goto send_sig;
  84
  85         for (i = 0; i < ARM_MAX_BRP; ++i) {
  86                 if (current->thread.debug.hbp_break[i] == bp) {
  87                         info.si_errno = (i << 1) + 1;
  88                         break;
  89                 }
  90         }
  91
  92         for (i = 0; i < ARM_MAX_WRP; ++i) {
  93                 if (current->thread.debug.hbp_watch[i] == bp) {
  94                         info.si_errno = -((i << 1) + 1);
  95                         break;
  96                 }
  97         }
  98
  99 send_sig:
 100 #endif
 101         force_sig_info(SIGTRAP, &info, current);
 102 }
 103
 104 /*
 105  * Unregister breakpoints from this task and reset the pointers in
 106  * the thread_struct.
 107  */
 108 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 109 {
 110         int i;
 111         struct thread_struct *t = &tsk->thread;
 112
 113         for (i = 0; i < ARM_MAX_BRP; i++) {
 114                 if (t->debug.hbp_break[i]) {
 115                         unregister_hw_breakpoint(t->debug.hbp_break[i]);
 116                         t->debug.hbp_break[i] = NULL;
 117                 }
 118         }
 119
 120         for (i = 0; i < ARM_MAX_WRP; i++) {
 121                 if (t->debug.hbp_watch[i]) {
 122                         unregister_hw_breakpoint(t->debug.hbp_watch[i]);
 123                         t->debug.hbp_watch[i] = NULL;
 124                 }
 125         }
 126 }
 127
 128 void ptrace_hw_copy_thread(struct task_struct *tsk)
 129 {
 130         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 131 }
 132
 133 static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
 134                                                struct task_struct *tsk,
 135                                                unsigned long idx)
 136 {
 137         struct perf_event *bp = ERR_PTR(-EINVAL);
 138
 139         switch (note_type) {
 140         case NT_ARM_HW_BREAK:
 141                 if (idx < ARM_MAX_BRP)
 142                         bp = tsk->thread.debug.hbp_break[idx];
 143                 break;
 144         case NT_ARM_HW_WATCH:
 145                 if (idx < ARM_MAX_WRP)
 146                         bp = tsk->thread.debug.hbp_watch[idx];
 147                 break;
 148         }
 149
 150         return bp;
 151 }
 152
 153 static int ptrace_hbp_set_event(unsigned int note_type,
 154                                 struct task_struct *tsk,
 155                                 unsigned long idx,
 156                                 struct perf_event *bp)
 157 {
 158         int err = -EINVAL;
 159
 160         switch (note_type) {
 161         case NT_ARM_HW_BREAK:
 162                 if (idx < ARM_MAX_BRP) {
 163                         tsk->thread.debug.hbp_break[idx] = bp;
 164                         err = 0;
 165                 }
 166                 break;
 167         case NT_ARM_HW_WATCH:
 168                 if (idx < ARM_MAX_WRP) {
 169                         tsk->thread.debug.hbp_watch[idx] = bp;
 170                         err = 0;
 171                 }
 172                 break;
 173         }
 174
 175         return err;
 176 }
 177
 178 static struct perf_event *ptrace_hbp_create(unsigned int note_type,
 179                                             struct task_struct *tsk,
 180                                             unsigned long idx)
 181 {
 182         struct perf_event *bp;
 183         struct perf_event_attr attr;
 184         int err, type;
 185
 186         switch (note_type) {
 187         case NT_ARM_HW_BREAK:
 188                 type = HW_BREAKPOINT_X;
 189                 break;
 190         case NT_ARM_HW_WATCH:
 191                 type = HW_BREAKPOINT_RW;
 192                 break;
 193         default:
 194                 return ERR_PTR(-EINVAL);
 195         }
 196
 197         ptrace_breakpoint_init(&attr);
 198
 199         /*
 200          * Initialise fields to sane defaults
 201          * (i.e. values that will pass validation).
 202          */
 203         attr.bp_addr    = 0;
 204         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 205         attr.bp_type    = type;
 206         attr.disabled   = 1;
 207
 208         bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk);
 209         if (IS_ERR(bp))
 210                 return bp;
 211
 212         err = ptrace_hbp_set_event(note_type, tsk, idx, bp);
 213         if (err)
 214                 return ERR_PTR(err);
 215
 216         return bp;
 217 }
 218
 219 static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
 220                                      struct arch_hw_breakpoint_ctrl ctrl,
 221                                      struct perf_event_attr *attr)
 222 {
 223         int err, len, type, disabled = !ctrl.enabled;
 224
 225         attr->disabled = disabled;
 226         if (disabled)
 227                 return 0;
 228
 229         err = arch_bp_generic_fields(ctrl, &len, &type);
 230         if (err)
 231                 return err;
 232
 233         switch (note_type) {
 234         case NT_ARM_HW_BREAK:
 235                 if ((type & HW_BREAKPOINT_X) != type)
 236                         return -EINVAL;
 237                 break;
 238         case NT_ARM_HW_WATCH:
 239                 if ((type & HW_BREAKPOINT_RW) != type)
 240                         return -EINVAL;
 241                 break;
 242         default:
 243                 return -EINVAL;
 244         }
 245
 246         attr->bp_len    = len;
 247         attr->bp_type   = type;
 248
 249         return 0;
 250 }
 251
 252 static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info)
 253 {
 254         u8 num;
 255         u32 reg = 0;
 256
 257         switch (note_type) {
 258         case NT_ARM_HW_BREAK:
 259                 num = hw_breakpoint_slots(TYPE_INST);
 260                 break;
 261         case NT_ARM_HW_WATCH:
 262                 num = hw_breakpoint_slots(TYPE_DATA);
 263                 break;
 264         default:
 265                 return -EINVAL;
 266         }
 267
 268         reg |= debug_monitors_arch();
 269         reg <<= 8;
 270         reg |= num;
 271
 272         *info = reg;
 273         return 0;
 274 }
 275
 276 static int ptrace_hbp_get_ctrl(unsigned int note_type,
 277                                struct task_struct *tsk,
 278                                unsigned long idx,
 279                                u32 *ctrl)
 280 {
 281         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 282
 283         if (IS_ERR(bp))
 284                 return PTR_ERR(bp);
 285
 286         *ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0;
 287         return 0;
 288 }
 289
 290 static int ptrace_hbp_get_addr(unsigned int note_type,
 291                                struct task_struct *tsk,
 292                                unsigned long idx,
 293                                u64 *addr)
 294 {
 295         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 296
 297         if (IS_ERR(bp))
 298                 return PTR_ERR(bp);
 299
 300         *addr = bp ? bp->attr.bp_addr : 0;
 301         return 0;
 302 }
 303
 304 static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type,
 305                                                         struct task_struct *tsk,
 306                                                         unsigned long idx)
 307 {
 308         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 309
 310         if (!bp)
 311                 bp = ptrace_hbp_create(note_type, tsk, idx);
 312
 313         return bp;
 314 }
 315
 316 static int ptrace_hbp_set_ctrl(unsigned int note_type,
 317                                struct task_struct *tsk,
 318                                unsigned long idx,
 319                                u32 uctrl)
 320 {
 321         int err;
 322         struct perf_event *bp;
 323         struct perf_event_attr attr;
 324         struct arch_hw_breakpoint_ctrl ctrl;
 325
 326         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 327         if (IS_ERR(bp)) {
 328                 err = PTR_ERR(bp);
 329                 return err;
 330         }
 331
 332         attr = bp->attr;
 333         decode_ctrl_reg(uctrl, &ctrl);
 334         err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
 335         if (err)
 336                 return err;
 337
 338         return modify_user_hw_breakpoint(bp, &attr);
 339 }
 340
 341 static int ptrace_hbp_set_addr(unsigned int note_type,
 342                                struct task_struct *tsk,
 343                                unsigned long idx,
 344                                u64 addr)
 345 {
 346         int err;
 347         struct perf_event *bp;
 348         struct perf_event_attr attr;
 349
 350         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 351         if (IS_ERR(bp)) {
 352                 err = PTR_ERR(bp);
 353                 return err;
 354         }
 355
 356         attr = bp->attr;
 357         attr.bp_addr = addr;
 358         err = modify_user_hw_breakpoint(bp, &attr);
 359         return err;
 360 }
 361
 362 #define PTRACE_HBP_ADDR_SZ      sizeof(u64)
 363 #define PTRACE_HBP_CTRL_SZ      sizeof(u32)
 364 #define PTRACE_HBP_PAD_SZ       sizeof(u32)
 365
 366 static int hw_break_get(struct task_struct *target,
 367                         const struct user_regset *regset,
 368                         unsigned int pos, unsigned int count,
 369                         void *kbuf, void __user *ubuf)
 370 {
 371         unsigned int note_type = regset->core_note_type;
 372         int ret, idx = 0, offset, limit;
 373         u32 info, ctrl;
 374         u64 addr;
 375
 376         /* Resource info */
 377         ret = ptrace_hbp_get_resource_info(note_type, &info);
 378         if (ret)
 379                 return ret;
 380
 381         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0,
 382                                   sizeof(info));
 383         if (ret)
 384                 return ret;
 385
 386         /* Pad */
 387         offset = offsetof(struct user_hwdebug_state, pad);
 388         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, offset,
 389                                        offset + PTRACE_HBP_PAD_SZ);
 390         if (ret)
 391                 return ret;
 392
 393         /* (address, ctrl) registers */
 394         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 395         limit = regset->n * regset->size;
 396         while (count && offset < limit) {
 397                 ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
 398                 if (ret)
 399                         return ret;
 400                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr,
 401                                           offset, offset + PTRACE_HBP_ADDR_SZ);
 402                 if (ret)
 403                         return ret;
 404                 offset += PTRACE_HBP_ADDR_SZ;
 405
 406                 ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
 407                 if (ret)
 408                         return ret;
 409                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl,
 410                                           offset, offset + PTRACE_HBP_CTRL_SZ);
 411                 if (ret)
 412                         return ret;
 413                 offset += PTRACE_HBP_CTRL_SZ;
 414
 415                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 416                                                offset,
 417                                                offset + PTRACE_HBP_PAD_SZ);
 418                 if (ret)
 419                         return ret;
 420                 offset += PTRACE_HBP_PAD_SZ;
 421                 idx++;
 422         }
 423
 424         return 0;
 425 }
 426
 427 static int hw_break_set(struct task_struct *target,
 428                         const struct user_regset *regset,
 429                         unsigned int pos, unsigned int count,
 430                         const void *kbuf, const void __user *ubuf)
 431 {
 432         unsigned int note_type = regset->core_note_type;
 433         int ret, idx = 0, offset, limit;
 434         u32 ctrl;
 435         u64 addr;
 436
 437         /* Resource info and pad */
 438         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 439         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset);
 440         if (ret)
 441                 return ret;
 442
 443         /* (address, ctrl) registers */
 444         limit = regset->n * regset->size;
 445         while (count && offset < limit) {
 446                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
 447                                          offset, offset + PTRACE_HBP_ADDR_SZ);
 448                 if (ret)
 449                         return ret;
 450                 ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
 451                 if (ret)
 452                         return ret;
 453                 offset += PTRACE_HBP_ADDR_SZ;
 454
 455                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
 456                                          offset, offset + PTRACE_HBP_CTRL_SZ);
 457                 if (ret)
 458                         return ret;
 459                 ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
 460                 if (ret)
 461                         return ret;
 462                 offset += PTRACE_HBP_CTRL_SZ;
 463
 464                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 465                                                 offset,
 466                                                 offset + PTRACE_HBP_PAD_SZ);
 467                 if (ret)
 468                         return ret;
 469                 offset += PTRACE_HBP_PAD_SZ;
 470                 idx++;
 471         }
 472
 473         return 0;
 474 }
 475 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 476
 477 static int gpr_get(struct task_struct *target,
 478                    const struct user_regset *regset,
 479                    unsigned int pos, unsigned int count,
 480                    void *kbuf, void __user *ubuf)
 481 {
 482         struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
 483         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 484 }
 485
 486 static int gpr_set(struct task_struct *target, const struct user_regset *regset,
 487                    unsigned int pos, unsigned int count,
 488                    const void *kbuf, const void __user *ubuf)
 489 {
 490         int ret;
 491         struct user_pt_regs newregs;
 492
 493         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
 494         if (ret)
 495                 return ret;
 496
 497         if (!valid_user_regs(&newregs))
 498                 return -EINVAL;
 499
 500         task_pt_regs(target)->user_regs = newregs;
 501         return 0;
 502 }
 503
 504 /*
 505  * TODO: update fp accessors for lazy context switching (sync/flush hwstate)
 506  */
 507 static int fpr_get(struct task_struct *target, const struct user_regset *regset,
 508                    unsigned int pos, unsigned int count,
 509                    void *kbuf, void __user *ubuf)
 510 {
 511         struct user_fpsimd_state *uregs;
 512         uregs = &target->thread.fpsimd_state.user_fpsimd;
 513         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 514 }
 515
 516 static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 517                    unsigned int pos, unsigned int count,
 518                    const void *kbuf, const void __user *ubuf)
 519 {
 520         int ret;
 521         struct user_fpsimd_state newstate;
 522
 523         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1);
 524         if (ret)
 525                 return ret;
 526
 527         target->thread.fpsimd_state.user_fpsimd = newstate;
 528         fpsimd_flush_task_state(target);
 529         return ret;
 530 }
 531
 532 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 533                    unsigned int pos, unsigned int count,
 534                    void *kbuf, void __user *ubuf)
 535 {
 536         unsigned long *tls = &target->thread.tp_value;
 537         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
 538 }
 539
 540 static int tls_set(struct task_struct *target, const struct user_regset *regset,
 541                    unsigned int pos, unsigned int count,
 542                    const void *kbuf, const void __user *ubuf)
 543 {
 544         int ret;
 545         unsigned long tls;
 546
 547         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 548         if (ret)
 549                 return ret;
 550
 551         target->thread.tp_value = tls;
 552         return ret;
 553 }
 554
 555 static int system_call_get(struct task_struct *target,
 556                            const struct user_regset *regset,
 557                            unsigned int pos, unsigned int count,
 558                            void *kbuf, void __user *ubuf)
 559 {
 560         int syscallno = task_pt_regs(target)->syscallno;
 561
 562         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 563                                    &syscallno, 0, -1);
 564 }
 565
 566 static int system_call_set(struct task_struct *target,
 567                            const struct user_regset *regset,
 568                            unsigned int pos, unsigned int count,
 569                            const void *kbuf, const void __user *ubuf)
 570 {
 571         int syscallno, ret;
 572
 573         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &syscallno, 0, -1);
 574         if (ret)
 575                 return ret;
 576
 577         task_pt_regs(target)->syscallno = syscallno;
 578         return ret;
 579 }
 580
 581 enum aarch64_regset {
 582         REGSET_GPR,
 583         REGSET_FPR,
 584         REGSET_TLS,
 585 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 586         REGSET_HW_BREAK,
 587         REGSET_HW_WATCH,
 588 #endif
 589         REGSET_SYSTEM_CALL,
 590 };
 591
 592 static const struct user_regset aarch64_regsets[] = {
 593         [REGSET_GPR] = {
 594                 .core_note_type = NT_PRSTATUS,
 595                 .n = sizeof(struct user_pt_regs) / sizeof(u64),
 596                 .size = sizeof(u64),
 597                 .align = sizeof(u64),
 598                 .get = gpr_get,
 599                 .set = gpr_set
 600         },
 601         [REGSET_FPR] = {
 602                 .core_note_type = NT_PRFPREG,
 603                 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
 604                 /*
 605                  * We pretend we have 32-bit registers because the fpsr and
 606                  * fpcr are 32-bits wide.
 607                  */
 608                 .size = sizeof(u32),
 609                 .align = sizeof(u32),
 610                 .get = fpr_get,
 611                 .set = fpr_set
 612         },
 613         [REGSET_TLS] = {
 614                 .core_note_type = NT_ARM_TLS,
 615                 .n = 1,
 616                 .size = sizeof(void *),
 617                 .align = sizeof(void *),
 618                 .get = tls_get,
 619                 .set = tls_set,
 620         },
 621 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 622         [REGSET_HW_BREAK] = {
 623                 .core_note_type = NT_ARM_HW_BREAK,
 624                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 625                 .size = sizeof(u32),
 626                 .align = sizeof(u32),
 627                 .get = hw_break_get,
 628                 .set = hw_break_set,
 629         },
 630         [REGSET_HW_WATCH] = {
 631                 .core_note_type = NT_ARM_HW_WATCH,
 632                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 633                 .size = sizeof(u32),
 634                 .align = sizeof(u32),
 635                 .get = hw_break_get,
 636                 .set = hw_break_set,
 637         },
 638 #endif
 639         [REGSET_SYSTEM_CALL] = {
 640                 .core_note_type = NT_ARM_SYSTEM_CALL,
 641                 .n = 1,
 642                 .size = sizeof(int),
 643                 .align = sizeof(int),
 644                 .get = system_call_get,
 645                 .set = system_call_set,
 646         },
 647 };
 648
 649 static const struct user_regset_view user_aarch64_view = {
 650         .name = "aarch64", .e_machine = EM_AARCH64,
 651         .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
 652 };
 653
 654 #ifdef CONFIG_COMPAT
 655 #include <linux/compat.h>
 656
 657 enum compat_regset {
 658         REGSET_COMPAT_GPR,
 659         REGSET_COMPAT_VFP,
 660 };
 661
 662 static int compat_gpr_get(struct task_struct *target,
 663                           const struct user_regset *regset,
 664                           unsigned int pos, unsigned int count,
 665                           void *kbuf, void __user *ubuf)
 666 {
 667         int ret = 0;
 668         unsigned int i, start, num_regs;
 669
 670         /* Calculate the number of AArch32 registers contained in count */
 671         num_regs = count / regset->size;
 672
 673         /* Convert pos into an register number */
 674         start = pos / regset->size;
 675
 676         if (start + num_regs > regset->n)
 677                 return -EIO;
 678
 679         for (i = 0; i < num_regs; ++i) {
 680                 unsigned int idx = start + i;
 681                 compat_ulong_t reg;
 682
 683                 switch (idx) {
 684                 case 15:
 685                         reg = task_pt_regs(target)->pc;
 686                         break;
 687                 case 16:
 688                         reg = task_pt_regs(target)->pstate;
 689                         break;
 690                 case 17:
 691                         reg = task_pt_regs(target)->orig_x0;
 692                         break;
 693                 default:
 694                         reg = task_pt_regs(target)->regs[idx];
 695                 }
 696
 697                 if (kbuf) {
 698                         memcpy(kbuf, &reg, sizeof(reg));
 699                         kbuf += sizeof(reg);
 700                 } else {
 701                         ret = copy_to_user(ubuf, &reg, sizeof(reg));
 702                         if (ret) {
 703                                 ret = -EFAULT;
 704                                 break;
 705                         }
 706
 707                         ubuf += sizeof(reg);
 708                 }
 709         }
 710
 711         return ret;
 712 }
 713
 714 static int compat_gpr_set(struct task_struct *target,
 715                           const struct user_regset *regset,
 716                           unsigned int pos, unsigned int count,
 717                           const void *kbuf, const void __user *ubuf)
 718 {
 719         struct pt_regs newregs;
 720         int ret = 0;
 721         unsigned int i, start, num_regs;
 722
 723         /* Calculate the number of AArch32 registers contained in count */
 724         num_regs = count / regset->size;
 725
 726         /* Convert pos into an register number */
 727         start = pos / regset->size;
 728
 729         if (start + num_regs > regset->n)
 730                 return -EIO;
 731
 732         newregs = *task_pt_regs(target);
 733
 734         for (i = 0; i < num_regs; ++i) {
 735                 unsigned int idx = start + i;
 736                 compat_ulong_t reg;
 737
 738                 if (kbuf) {
 739                         memcpy(&reg, kbuf, sizeof(reg));
 740                         kbuf += sizeof(reg);
 741                 } else {
 742                         ret = copy_from_user(&reg, ubuf, sizeof(reg));
 743                         if (ret) {
 744                                 ret = -EFAULT;
 745                                 break;
 746                         }
 747
 748                         ubuf += sizeof(reg);
 749                 }
 750
 751                 switch (idx) {
 752                 case 15:
 753                         newregs.pc = reg;
 754                         break;
 755                 case 16:
 756                         newregs.pstate = reg;
 757                         break;
 758                 case 17:
 759                         newregs.orig_x0 = reg;
 760                         break;
 761                 default:
 762                         newregs.regs[idx] = reg;
 763                 }
 764
 765         }
 766
 767         if (valid_user_regs(&newregs.user_regs))
 768                 *task_pt_regs(target) = newregs;
 769         else
 770                 ret = -EINVAL;
 771
 772         return ret;
 773 }
 774
 775 static int compat_vfp_get(struct task_struct *target,
 776                           const struct user_regset *regset,
 777                           unsigned int pos, unsigned int count,
 778                           void *kbuf, void __user *ubuf)
 779 {
 780         struct user_fpsimd_state *uregs;
 781         compat_ulong_t fpscr;
 782         int ret;
 783
 784         uregs = &target->thread.fpsimd_state.user_fpsimd;
 785
 786         /*
 787          * The VFP registers are packed into the fpsimd_state, so they all sit
 788          * nicely together for us. We just need to create the fpscr separately.
 789          */
 790         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
 791                                   VFP_STATE_SIZE - sizeof(compat_ulong_t));
 792
 793         if (count && !ret) {
 794                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
 795                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
 796                 ret = put_user(fpscr, (compat_ulong_t *)ubuf);
 797         }
 798
 799         return ret;
 800 }
 801
 802 static int compat_vfp_set(struct task_struct *target,
 803                           const struct user_regset *regset,
 804                           unsigned int pos, unsigned int count,
 805                           const void *kbuf, const void __user *ubuf)
 806 {
 807         struct user_fpsimd_state *uregs;
 808         compat_ulong_t fpscr;
 809         int ret;
 810
 811         if (pos + count > VFP_STATE_SIZE)
 812                 return -EIO;
 813
 814         uregs = &target->thread.fpsimd_state.user_fpsimd;
 815
 816         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
 817                                  VFP_STATE_SIZE - sizeof(compat_ulong_t));
 818
 819         if (count && !ret) {
 820                 ret = get_user(fpscr, (compat_ulong_t *)ubuf);
 821                 uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
 822                 uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
 823         }
 824
 825         fpsimd_flush_task_state(target);
 826         return ret;
 827 }
 828
 829 static int compat_tls_get(struct task_struct *target,
 830                           const struct user_regset *regset, unsigned int pos,
 831                           unsigned int count, void *kbuf, void __user *ubuf)
 832 {
 833         compat_ulong_t tls = (compat_ulong_t)target->thread.tp_value;
 834         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 835 }
 836
 837 static int compat_tls_set(struct task_struct *target,
 838                           const struct user_regset *regset, unsigned int pos,
 839                           unsigned int count, const void *kbuf,
 840                           const void __user *ubuf)
 841 {
 842         int ret;
 843         compat_ulong_t tls;
 844
 845         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 846         if (ret)
 847                 return ret;
 848
 849         target->thread.tp_value = tls;
 850         return ret;
 851 }
 852
 853 static const struct user_regset aarch32_regsets[] = {
 854         [REGSET_COMPAT_GPR] = {
 855                 .core_note_type = NT_PRSTATUS,
 856                 .n = COMPAT_ELF_NGREG,
 857                 .size = sizeof(compat_elf_greg_t),
 858                 .align = sizeof(compat_elf_greg_t),
 859                 .get = compat_gpr_get,
 860                 .set = compat_gpr_set
 861         },
 862         [REGSET_COMPAT_VFP] = {
 863                 .core_note_type = NT_ARM_VFP,
 864                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
 865                 .size = sizeof(compat_ulong_t),
 866                 .align = sizeof(compat_ulong_t),
 867                 .get = compat_vfp_get,
 868                 .set = compat_vfp_set
 869         },
 870 };
 871
 872 static const struct user_regset_view user_aarch32_view = {
 873         .name = "aarch32", .e_machine = EM_ARM,
 874         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
 875 };
 876
 877 static const struct user_regset aarch32_ptrace_regsets[] = {
 878         [REGSET_GPR] = {
 879                 .core_note_type = NT_PRSTATUS,
 880                 .n = COMPAT_ELF_NGREG,
 881                 .size = sizeof(compat_elf_greg_t),
 882                 .align = sizeof(compat_elf_greg_t),
 883                 .get = compat_gpr_get,
 884                 .set = compat_gpr_set
 885         },
 886         [REGSET_FPR] = {
 887                 .core_note_type = NT_ARM_VFP,
 888                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
 889                 .size = sizeof(compat_ulong_t),
 890                 .align = sizeof(compat_ulong_t),
 891                 .get = compat_vfp_get,
 892                 .set = compat_vfp_set
 893         },
 894         [REGSET_TLS] = {
 895                 .core_note_type = NT_ARM_TLS,
 896                 .n = 1,
 897                 .size = sizeof(compat_ulong_t),
 898                 .align = sizeof(compat_ulong_t),
 899                 .get = compat_tls_get,
 900                 .set = compat_tls_set,
 901         },
 902 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 903         [REGSET_HW_BREAK] = {
 904                 .core_note_type = NT_ARM_HW_BREAK,
 905                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 906                 .size = sizeof(u32),
 907                 .align = sizeof(u32),
 908                 .get = hw_break_get,
 909                 .set = hw_break_set,
 910         },
 911         [REGSET_HW_WATCH] = {
 912                 .core_note_type = NT_ARM_HW_WATCH,
 913                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 914                 .size = sizeof(u32),
 915                 .align = sizeof(u32),
 916                 .get = hw_break_get,
 917                 .set = hw_break_set,
 918         },
 919 #endif
 920         [REGSET_SYSTEM_CALL] = {
 921                 .core_note_type = NT_ARM_SYSTEM_CALL,
 922                 .n = 1,
 923                 .size = sizeof(int),
 924                 .align = sizeof(int),
 925                 .get = system_call_get,
 926                 .set = system_call_set,
 927         },
 928 };
 929
 930 static const struct user_regset_view user_aarch32_ptrace_view = {
 931         .name = "aarch32", .e_machine = EM_ARM,
 932         .regsets = aarch32_ptrace_regsets, .n = ARRAY_SIZE(aarch32_ptrace_regsets)
 933 };
 934
 935 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
 936                                    compat_ulong_t __user *ret)
 937 {
 938         compat_ulong_t tmp;
 939
 940         if (off & 3)
 941                 return -EIO;
 942
 943         if (off == COMPAT_PT_TEXT_ADDR)
 944                 tmp = tsk->mm->start_code;
 945         else if (off == COMPAT_PT_DATA_ADDR)
 946                 tmp = tsk->mm->start_data;
 947         else if (off == COMPAT_PT_TEXT_END_ADDR)
 948                 tmp = tsk->mm->end_code;
 949         else if (off < sizeof(compat_elf_gregset_t))
 950                 return copy_regset_to_user(tsk, &user_aarch32_view,
 951                                            REGSET_COMPAT_GPR, off,
 952                                            sizeof(compat_ulong_t), ret);
 953         else if (off >= COMPAT_USER_SZ)
 954                 return -EIO;
 955         else
 956                 tmp = 0;
 957
 958         return put_user(tmp, ret);
 959 }
 960
 961 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
 962                                     compat_ulong_t val)
 963 {
 964         int ret;
 965         mm_segment_t old_fs = get_fs();
 966
 967         if (off & 3 || off >= COMPAT_USER_SZ)
 968                 return -EIO;
 969
 970         if (off >= sizeof(compat_elf_gregset_t))
 971                 return 0;
 972
 973         set_fs(KERNEL_DS);
 974         ret = copy_regset_from_user(tsk, &user_aarch32_view,
 975                                     REGSET_COMPAT_GPR, off,
 976                                     sizeof(compat_ulong_t),
 977                                     &val);
 978         set_fs(old_fs);
 979
 980         return ret;
 981 }
 982
 983 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 984
 985 /*
 986  * Convert a virtual register number into an index for a thread_info
 987  * breakpoint array. Breakpoints are identified using positive numbers
 988  * whilst watchpoints are negative. The registers are laid out as pairs
 989  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
 990  * Register 0 is reserved for describing resource information.
 991  */
 992 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
 993 {
 994         return (abs(num) - 1) >> 1;
 995 }
 996
 997 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
 998 {
 999         u8 num_brps, num_wrps, debug_arch, wp_len;
1000         u32 reg = 0;
1001
1002         num_brps        = hw_breakpoint_slots(TYPE_INST);
1003         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
1004
1005         debug_arch      = debug_monitors_arch();
1006         wp_len          = 8;
1007         reg             |= debug_arch;
1008         reg             <<= 8;
1009         reg             |= wp_len;
1010         reg             <<= 8;
1011         reg             |= num_wrps;
1012         reg             <<= 8;
1013         reg             |= num_brps;
1014
1015         *kdata = reg;
1016         return 0;
1017 }
1018
1019 static int compat_ptrace_hbp_get(unsigned int note_type,
1020                                  struct task_struct *tsk,
1021                                  compat_long_t num,
1022                                  u32 *kdata)
1023 {
1024         u64 addr = 0;
1025         u32 ctrl = 0;
1026
1027         int err, idx = compat_ptrace_hbp_num_to_idx(num);;
1028
1029         if (num & 1) {
1030                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
1031                 *kdata = (u32)addr;
1032         } else {
1033                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
1034                 *kdata = ctrl;
1035         }
1036
1037         return err;
1038 }
1039
1040 static int compat_ptrace_hbp_set(unsigned int note_type,
1041                                  struct task_struct *tsk,
1042                                  compat_long_t num,
1043                                  u32 *kdata)
1044 {
1045         u64 addr;
1046         u32 ctrl;
1047
1048         int err, idx = compat_ptrace_hbp_num_to_idx(num);
1049
1050         if (num & 1) {
1051                 addr = *kdata;
1052                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
1053         } else {
1054                 ctrl = *kdata;
1055                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
1056         }
1057
1058         return err;
1059 }
1060
1061 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
1062                                     compat_ulong_t __user *data)
1063 {
1064         int ret;
1065         u32 kdata;
1066         mm_segment_t old_fs = get_fs();
1067
1068         set_fs(KERNEL_DS);
1069         /* Watchpoint */
1070         if (num < 0) {
1071                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
1072         /* Resource info */
1073         } else if (num == 0) {
1074                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
1075         /* Breakpoint */
1076         } else {
1077                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
1078         }
1079         set_fs(old_fs);
1080
1081         if (!ret)
1082                 ret = put_user(kdata, data);
1083
1084         return ret;
1085 }
1086
1087 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
1088                                     compat_ulong_t __user *data)
1089 {
1090         int ret;
1091         u32 kdata = 0;
1092         mm_segment_t old_fs = get_fs();
1093
1094         if (num == 0)
1095                 return 0;
1096
1097         ret = get_user(kdata, data);
1098         if (ret)
1099                 return ret;
1100
1101         set_fs(KERNEL_DS);
1102         if (num < 0)
1103                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
1104         else
1105                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
1106         set_fs(old_fs);
1107
1108         return ret;
1109 }
1110 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
1111
1112 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1113                         compat_ulong_t caddr, compat_ulong_t cdata)
1114 {
1115         unsigned long addr = caddr;
1116         unsigned long data = cdata;
1117         void __user *datap = compat_ptr(data);
1118         int ret;
1119
1120         switch (request) {
1121                 case PTRACE_PEEKUSR:
1122                         ret = compat_ptrace_read_user(child, addr, datap);
1123                         break;
1124
1125                 case PTRACE_POKEUSR:
1126                         ret = compat_ptrace_write_user(child, addr, data);
1127                         break;
1128
1129                 case COMPAT_PTRACE_GETREGS:
1130                         ret = copy_regset_to_user(child,
1131                                                   &user_aarch32_view,
1132                                                   REGSET_COMPAT_GPR,
1133                                                   0, sizeof(compat_elf_gregset_t),
1134                                                   datap);
1135                         break;
1136
1137                 case COMPAT_PTRACE_SETREGS:
1138                         ret = copy_regset_from_user(child,
1139                                                     &user_aarch32_view,
1140                                                     REGSET_COMPAT_GPR,
1141                                                     0, sizeof(compat_elf_gregset_t),
1142                                                     datap);
1143                         break;
1144
1145                 case COMPAT_PTRACE_GET_THREAD_AREA:
1146                         ret = put_user((compat_ulong_t)child->thread.tp_value,
1147                                        (compat_ulong_t __user *)datap);
1148                         break;
1149
1150                 case COMPAT_PTRACE_SET_SYSCALL:
1151                         task_pt_regs(child)->syscallno = data;
1152                         ret = 0;
1153                         break;
1154
1155                 case COMPAT_PTRACE_GETVFPREGS:
1156                         ret = copy_regset_to_user(child,
1157                                                   &user_aarch32_view,
1158                                                   REGSET_COMPAT_VFP,
1159                                                   0, VFP_STATE_SIZE,
1160                                                   datap);
1161                         break;
1162
1163                 case COMPAT_PTRACE_SETVFPREGS:
1164                         ret = copy_regset_from_user(child,
1165                                                     &user_aarch32_view,
1166                                                     REGSET_COMPAT_VFP,
1167                                                     0, VFP_STATE_SIZE,
1168                                                     datap);
1169                         break;
1170
1171 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1172                 case COMPAT_PTRACE_GETHBPREGS:
1173                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1174                         break;
1175
1176                 case COMPAT_PTRACE_SETHBPREGS:
1177                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1178                         break;
1179 #endif
1180
1181                 default:
1182                         ret = compat_ptrace_request(child, request, addr,
1183                                                     data);
1184                         break;
1185         }
1186
1187         return ret;
1188 }
1189 #endif /* CONFIG_COMPAT */
1190
1191 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1192 {
1193 #ifdef CONFIG_COMPAT
1194         /*
1195          * Core dumping of 32-bit tasks or compat ptrace requests must use the
1196          * user_aarch32_view compatible with arm32. Native ptrace requests on
1197          * 32-bit children use an extended user_aarch32_ptrace_view to allow
1198          * access to the TLS register.
1199          */
1200         if (is_compat_task())
1201                 return &user_aarch32_view;
1202         else if (is_compat_thread(task_thread_info(task)))
1203                 return &user_aarch32_ptrace_view;
1204 #endif
1205         return &user_aarch64_view;
1206 }
1207
1208 long arch_ptrace(struct task_struct *child, long request,
1209                  unsigned long addr, unsigned long data)
1210 {
1211         return ptrace_request(child, request, addr, data);
1212 }
1213
1214 enum ptrace_syscall_dir {
1215         PTRACE_SYSCALL_ENTER = 0,
1216         PTRACE_SYSCALL_EXIT,
1217 };
1218
1219 static void tracehook_report_syscall(struct pt_regs *regs,
1220                                      enum ptrace_syscall_dir dir)
1221 {
1222         int regno;
1223         unsigned long saved_reg;
1224
1225         /*
1226          * A scratch register (ip(r12) on AArch32, x7 on AArch64) is
1227          * used to denote syscall entry/exit:
1228          */
1229         regno = (is_compat_task() ? 12 : 7);
1230         saved_reg = regs->regs[regno];
1231         regs->regs[regno] = dir;
1232
1233         if (dir == PTRACE_SYSCALL_EXIT)
1234                 tracehook_report_syscall_exit(regs, 0);
1235         else if (tracehook_report_syscall_entry(regs))
1236                 regs->syscallno = ~0UL;
1237
1238         regs->regs[regno] = saved_reg;
1239 }
1240
1241 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
1242 {
1243         /* Do the secure computing check first; failures should be fast. */
1244         if (secure_computing() == -1)
1245                 return -1;
1246
1247         if (test_thread_flag(TIF_SYSCALL_TRACE))
1248                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1249
1250         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1251                 trace_sys_enter(regs, regs->syscallno);
1252
1253         audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1],
1254                             regs->regs[2], regs->regs[3]);
1255
1256         return regs->syscallno;
1257 }
1258
1259 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
1260 {
1261         audit_syscall_exit(regs);
1262
1263         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1264                 trace_sys_exit(regs, regs_return_value(regs));
1265
1266         if (test_thread_flag(TIF_SYSCALL_TRACE))
1267                 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1268 }