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         return ret;
 525 }
 526
 527 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 528                    unsigned int pos, unsigned int count,
 529                    void *kbuf, void __user *ubuf)
 530 {
 531         unsigned long *tls = &target->thread.tp_value;
 532         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
 533 }
 534
 535 static int tls_set(struct task_struct *target, const struct user_regset *regset,
 536                    unsigned int pos, unsigned int count,
 537                    const void *kbuf, const void __user *ubuf)
 538 {
 539         int ret;
 540         unsigned long tls;
 541
 542         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 543         if (ret)
 544                 return ret;
 545
 546         target->thread.tp_value = tls;
 547         return ret;
 548 }
 549
 550 enum aarch64_regset {
 551         REGSET_GPR,
 552         REGSET_FPR,
 553         REGSET_TLS,
 554 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 555         REGSET_HW_BREAK,
 556         REGSET_HW_WATCH,
 557 #endif
 558 };
 559
 560 static const struct user_regset aarch64_regsets[] = {
 561         [REGSET_GPR] = {
 562                 .core_note_type = NT_PRSTATUS,
 563                 .n = sizeof(struct user_pt_regs) / sizeof(u64),
 564                 .size = sizeof(u64),
 565                 .align = sizeof(u64),
 566                 .get = gpr_get,
 567                 .set = gpr_set
 568         },
 569         [REGSET_FPR] = {
 570                 .core_note_type = NT_PRFPREG,
 571                 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
 572                 /*
 573                  * We pretend we have 32-bit registers because the fpsr and
 574                  * fpcr are 32-bits wide.
 575                  */
 576                 .size = sizeof(u32),
 577                 .align = sizeof(u32),
 578                 .get = fpr_get,
 579                 .set = fpr_set
 580         },
 581         [REGSET_TLS] = {
 582                 .core_note_type = NT_ARM_TLS,
 583                 .n = 1,
 584                 .size = sizeof(void *),
 585                 .align = sizeof(void *),
 586                 .get = tls_get,
 587                 .set = tls_set,
 588         },
 589 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 590         [REGSET_HW_BREAK] = {
 591                 .core_note_type = NT_ARM_HW_BREAK,
 592                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 593                 .size = sizeof(u32),
 594                 .align = sizeof(u32),
 595                 .get = hw_break_get,
 596                 .set = hw_break_set,
 597         },
 598         [REGSET_HW_WATCH] = {
 599                 .core_note_type = NT_ARM_HW_WATCH,
 600                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 601                 .size = sizeof(u32),
 602                 .align = sizeof(u32),
 603                 .get = hw_break_get,
 604                 .set = hw_break_set,
 605         },
 606 #endif
 607 };
 608
 609 static const struct user_regset_view user_aarch64_view = {
 610         .name = "aarch64", .e_machine = EM_AARCH64,
 611         .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
 612 };
 613
 614 #ifdef CONFIG_COMPAT
 615 #include <linux/compat.h>
 616
 617 enum compat_regset {
 618         REGSET_COMPAT_GPR,
 619         REGSET_COMPAT_VFP,
 620 };
 621
 622 static int compat_gpr_get(struct task_struct *target,
 623                           const struct user_regset *regset,
 624                           unsigned int pos, unsigned int count,
 625                           void *kbuf, void __user *ubuf)
 626 {
 627         int ret = 0;
 628         unsigned int i, start, num_regs;
 629
 630         /* Calculate the number of AArch32 registers contained in count */
 631         num_regs = count / regset->size;
 632
 633         /* Convert pos into an register number */
 634         start = pos / regset->size;
 635
 636         if (start + num_regs > regset->n)
 637                 return -EIO;
 638
 639         for (i = 0; i < num_regs; ++i) {
 640                 unsigned int idx = start + i;
 641                 compat_ulong_t reg;
 642
 643                 switch (idx) {
 644                 case 15:
 645                         reg = task_pt_regs(target)->pc;
 646                         break;
 647                 case 16:
 648                         reg = task_pt_regs(target)->pstate;
 649                         break;
 650                 case 17:
 651                         reg = task_pt_regs(target)->orig_x0;
 652                         break;
 653                 default:
 654                         reg = task_pt_regs(target)->regs[idx];
 655                 }
 656
 657                 ret = copy_to_user(ubuf, &reg, sizeof(reg));
 658                 if (ret)
 659                         break;
 660
 661                 ubuf += sizeof(reg);
 662         }
 663
 664         return ret;
 665 }
 666
 667 static int compat_gpr_set(struct task_struct *target,
 668                           const struct user_regset *regset,
 669                           unsigned int pos, unsigned int count,
 670                           const void *kbuf, const void __user *ubuf)
 671 {
 672         struct pt_regs newregs;
 673         int ret = 0;
 674         unsigned int i, start, num_regs;
 675
 676         /* Calculate the number of AArch32 registers contained in count */
 677         num_regs = count / regset->size;
 678
 679         /* Convert pos into an register number */
 680         start = pos / regset->size;
 681
 682         if (start + num_regs > regset->n)
 683                 return -EIO;
 684
 685         newregs = *task_pt_regs(target);
 686
 687         for (i = 0; i < num_regs; ++i) {
 688                 unsigned int idx = start + i;
 689                 compat_ulong_t reg;
 690
 691                 ret = copy_from_user(&reg, ubuf, sizeof(reg));
 692                 if (ret)
 693                         return ret;
 694
 695                 ubuf += sizeof(reg);
 696
 697                 switch (idx) {
 698                 case 15:
 699                         newregs.pc = reg;
 700                         break;
 701                 case 16:
 702                         newregs.pstate = reg;
 703                         break;
 704                 case 17:
 705                         newregs.orig_x0 = reg;
 706                         break;
 707                 default:
 708                         newregs.regs[idx] = reg;
 709                 }
 710
 711         }
 712
 713         if (valid_user_regs(&newregs.user_regs))
 714                 *task_pt_regs(target) = newregs;
 715         else
 716                 ret = -EINVAL;
 717
 718         return ret;
 719 }
 720
 721 static int compat_vfp_get(struct task_struct *target,
 722                           const struct user_regset *regset,
 723                           unsigned int pos, unsigned int count,
 724                           void *kbuf, void __user *ubuf)
 725 {
 726         struct user_fpsimd_state *uregs;
 727         compat_ulong_t fpscr;
 728         int ret;
 729
 730         uregs = &target->thread.fpsimd_state.user_fpsimd;
 731
 732         /*
 733          * The VFP registers are packed into the fpsimd_state, so they all sit
 734          * nicely together for us. We just need to create the fpscr separately.
 735          */
 736         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
 737                                   VFP_STATE_SIZE - sizeof(compat_ulong_t));
 738
 739         if (count && !ret) {
 740                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
 741                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
 742                 ret = put_user(fpscr, (compat_ulong_t *)ubuf);
 743         }
 744
 745         return ret;
 746 }
 747
 748 static int compat_vfp_set(struct task_struct *target,
 749                           const struct user_regset *regset,
 750                           unsigned int pos, unsigned int count,
 751                           const void *kbuf, const void __user *ubuf)
 752 {
 753         struct user_fpsimd_state *uregs;
 754         compat_ulong_t fpscr;
 755         int ret;
 756
 757         if (pos + count > VFP_STATE_SIZE)
 758                 return -EIO;
 759
 760         uregs = &target->thread.fpsimd_state.user_fpsimd;
 761
 762         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
 763                                  VFP_STATE_SIZE - sizeof(compat_ulong_t));
 764
 765         if (count && !ret) {
 766                 ret = get_user(fpscr, (compat_ulong_t *)ubuf);
 767                 uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
 768                 uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
 769         }
 770
 771         return ret;
 772 }
 773
 774 static const struct user_regset aarch32_regsets[] = {
 775         [REGSET_COMPAT_GPR] = {
 776                 .core_note_type = NT_PRSTATUS,
 777                 .n = COMPAT_ELF_NGREG,
 778                 .size = sizeof(compat_elf_greg_t),
 779                 .align = sizeof(compat_elf_greg_t),
 780                 .get = compat_gpr_get,
 781                 .set = compat_gpr_set
 782         },
 783         [REGSET_COMPAT_VFP] = {
 784                 .core_note_type = NT_ARM_VFP,
 785                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
 786                 .size = sizeof(compat_ulong_t),
 787                 .align = sizeof(compat_ulong_t),
 788                 .get = compat_vfp_get,
 789                 .set = compat_vfp_set
 790         },
 791 };
 792
 793 static const struct user_regset_view user_aarch32_view = {
 794         .name = "aarch32", .e_machine = EM_ARM,
 795         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
 796 };
 797
 798 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
 799                                    compat_ulong_t __user *ret)
 800 {
 801         compat_ulong_t tmp;
 802
 803         if (off & 3)
 804                 return -EIO;
 805
 806         if (off == COMPAT_PT_TEXT_ADDR)
 807                 tmp = tsk->mm->start_code;
 808         else if (off == COMPAT_PT_DATA_ADDR)
 809                 tmp = tsk->mm->start_data;
 810         else if (off == COMPAT_PT_TEXT_END_ADDR)
 811                 tmp = tsk->mm->end_code;
 812         else if (off < sizeof(compat_elf_gregset_t))
 813                 return copy_regset_to_user(tsk, &user_aarch32_view,
 814                                            REGSET_COMPAT_GPR, off,
 815                                            sizeof(compat_ulong_t), ret);
 816         else if (off >= COMPAT_USER_SZ)
 817                 return -EIO;
 818         else
 819                 tmp = 0;
 820
 821         return put_user(tmp, ret);
 822 }
 823
 824 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
 825                                     compat_ulong_t val)
 826 {
 827         int ret;
 828         mm_segment_t old_fs = get_fs();
 829
 830         if (off & 3 || off >= COMPAT_USER_SZ)
 831                 return -EIO;
 832
 833         if (off >= sizeof(compat_elf_gregset_t))
 834                 return 0;
 835
 836         set_fs(KERNEL_DS);
 837         ret = copy_regset_from_user(tsk, &user_aarch32_view,
 838                                     REGSET_COMPAT_GPR, off,
 839                                     sizeof(compat_ulong_t),
 840                                     &val);
 841         set_fs(old_fs);
 842
 843         return ret;
 844 }
 845
 846 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 847
 848 /*
 849  * Convert a virtual register number into an index for a thread_info
 850  * breakpoint array. Breakpoints are identified using positive numbers
 851  * whilst watchpoints are negative. The registers are laid out as pairs
 852  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
 853  * Register 0 is reserved for describing resource information.
 854  */
 855 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
 856 {
 857         return (abs(num) - 1) >> 1;
 858 }
 859
 860 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
 861 {
 862         u8 num_brps, num_wrps, debug_arch, wp_len;
 863         u32 reg = 0;
 864
 865         num_brps        = hw_breakpoint_slots(TYPE_INST);
 866         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
 867
 868         debug_arch      = debug_monitors_arch();
 869         wp_len          = 8;
 870         reg             |= debug_arch;
 871         reg             <<= 8;
 872         reg             |= wp_len;
 873         reg             <<= 8;
 874         reg             |= num_wrps;
 875         reg             <<= 8;
 876         reg             |= num_brps;
 877
 878         *kdata = reg;
 879         return 0;
 880 }
 881
 882 static int compat_ptrace_hbp_get(unsigned int note_type,
 883                                  struct task_struct *tsk,
 884                                  compat_long_t num,
 885                                  u32 *kdata)
 886 {
 887         u64 addr = 0;
 888         u32 ctrl = 0;
 889
 890         int err, idx = compat_ptrace_hbp_num_to_idx(num);;
 891
 892         if (num & 1) {
 893                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
 894                 *kdata = (u32)addr;
 895         } else {
 896                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
 897                 *kdata = ctrl;
 898         }
 899
 900         return err;
 901 }
 902
 903 static int compat_ptrace_hbp_set(unsigned int note_type,
 904                                  struct task_struct *tsk,
 905                                  compat_long_t num,
 906                                  u32 *kdata)
 907 {
 908         u64 addr;
 909         u32 ctrl;
 910
 911         int err, idx = compat_ptrace_hbp_num_to_idx(num);
 912
 913         if (num & 1) {
 914                 addr = *kdata;
 915                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
 916         } else {
 917                 ctrl = *kdata;
 918                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
 919         }
 920
 921         return err;
 922 }
 923
 924 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
 925                                     compat_ulong_t __user *data)
 926 {
 927         int ret;
 928         u32 kdata;
 929         mm_segment_t old_fs = get_fs();
 930
 931         set_fs(KERNEL_DS);
 932         /* Watchpoint */
 933         if (num < 0) {
 934                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
 935         /* Resource info */
 936         } else if (num == 0) {
 937                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
 938         /* Breakpoint */
 939         } else {
 940                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
 941         }
 942         set_fs(old_fs);
 943
 944         if (!ret)
 945                 ret = put_user(kdata, data);
 946
 947         return ret;
 948 }
 949
 950 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
 951                                     compat_ulong_t __user *data)
 952 {
 953         int ret;
 954         u32 kdata = 0;
 955         mm_segment_t old_fs = get_fs();
 956
 957         if (num == 0)
 958                 return 0;
 959
 960         ret = get_user(kdata, data);
 961         if (ret)
 962                 return ret;
 963
 964         set_fs(KERNEL_DS);
 965         if (num < 0)
 966                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
 967         else
 968                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
 969         set_fs(old_fs);
 970
 971         return ret;
 972 }
 973 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 974
 975 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 976                         compat_ulong_t caddr, compat_ulong_t cdata)
 977 {
 978         unsigned long addr = caddr;
 979         unsigned long data = cdata;
 980         void __user *datap = compat_ptr(data);
 981         int ret;
 982
 983         switch (request) {
 984                 case PTRACE_PEEKUSR:
 985                         ret = compat_ptrace_read_user(child, addr, datap);
 986                         break;
 987
 988                 case PTRACE_POKEUSR:
 989                         ret = compat_ptrace_write_user(child, addr, data);
 990                         break;
 991
 992                 case COMPAT_PTRACE_GETREGS:
 993                         ret = copy_regset_to_user(child,
 994                                                   &user_aarch32_view,
 995                                                   REGSET_COMPAT_GPR,
 996                                                   0, sizeof(compat_elf_gregset_t),
 997                                                   datap);
 998                         break;
 999
1000                 case COMPAT_PTRACE_SETREGS:
1001                         ret = copy_regset_from_user(child,
1002                                                     &user_aarch32_view,
1003                                                     REGSET_COMPAT_GPR,
1004                                                     0, sizeof(compat_elf_gregset_t),
1005                                                     datap);
1006                         break;
1007
1008                 case COMPAT_PTRACE_GET_THREAD_AREA:
1009                         ret = put_user((compat_ulong_t)child->thread.tp_value,
1010                                        (compat_ulong_t __user *)datap);
1011                         break;
1012
1013                 case COMPAT_PTRACE_SET_SYSCALL:
1014                         task_pt_regs(child)->syscallno = data;
1015                         ret = 0;
1016                         break;
1017
1018                 case COMPAT_PTRACE_GETVFPREGS:
1019                         ret = copy_regset_to_user(child,
1020                                                   &user_aarch32_view,
1021                                                   REGSET_COMPAT_VFP,
1022                                                   0, VFP_STATE_SIZE,
1023                                                   datap);
1024                         break;
1025
1026                 case COMPAT_PTRACE_SETVFPREGS:
1027                         ret = copy_regset_from_user(child,
1028                                                     &user_aarch32_view,
1029                                                     REGSET_COMPAT_VFP,
1030                                                     0, VFP_STATE_SIZE,
1031                                                     datap);
1032                         break;
1033
1034 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1035                 case COMPAT_PTRACE_GETHBPREGS:
1036                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1037                         break;
1038
1039                 case COMPAT_PTRACE_SETHBPREGS:
1040                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1041                         break;
1042 #endif
1043
1044                 default:
1045                         ret = compat_ptrace_request(child, request, addr,
1046                                                     data);
1047                         break;
1048         }
1049
1050         return ret;
1051 }
1052 #endif /* CONFIG_COMPAT */
1053
1054 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1055 {
1056 #ifdef CONFIG_COMPAT
1057         if (is_compat_thread(task_thread_info(task)))
1058                 return &user_aarch32_view;
1059 #endif
1060         return &user_aarch64_view;
1061 }
1062
1063 long arch_ptrace(struct task_struct *child, long request,
1064                  unsigned long addr, unsigned long data)
1065 {
1066         return ptrace_request(child, request, addr, data);
1067 }
1068
1069 enum ptrace_syscall_dir {
1070         PTRACE_SYSCALL_ENTER = 0,
1071         PTRACE_SYSCALL_EXIT,
1072 };
1073
1074 static void tracehook_report_syscall(struct pt_regs *regs,
1075                                      enum ptrace_syscall_dir dir)
1076 {
1077         int regno;
1078         unsigned long saved_reg;
1079
1080         /*
1081          * A scratch register (ip(r12) on AArch32, x7 on AArch64) is
1082          * used to denote syscall entry/exit:
1083          */
1084         regno = (is_compat_task() ? 12 : 7);
1085         saved_reg = regs->regs[regno];
1086         regs->regs[regno] = dir;
1087
1088         if (dir == PTRACE_SYSCALL_EXIT)
1089                 tracehook_report_syscall_exit(regs, 0);
1090         else if (tracehook_report_syscall_entry(regs))
1091                 regs->syscallno = ~0UL;
1092
1093         regs->regs[regno] = saved_reg;
1094 }
1095
1096 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
1097 {
1098         if (test_thread_flag(TIF_SYSCALL_TRACE))
1099                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1100
1101         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1102                 trace_sys_enter(regs, regs->syscallno);
1103
1104         return regs->syscallno;
1105 }
1106
1107 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
1108 {
1109         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1110                 trace_sys_exit(regs, regs_return_value(regs));
1111
1112         if (test_thread_flag(TIF_SYSCALL_TRACE))
1113                 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1114 }