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