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                 if (kbuf) {
 659                         memcpy(kbuf, &reg, sizeof(reg));
 660                         kbuf += sizeof(reg);
 661                 } else {
 662                         ret = copy_to_user(ubuf, &reg, sizeof(reg));
 663                         if (ret)
 664                                 break;
 665
 666                         ubuf += sizeof(reg);
 667                 }
 668         }
 669
 670         return ret;
 671 }
 672
 673 static int compat_gpr_set(struct task_struct *target,
 674                           const struct user_regset *regset,
 675                           unsigned int pos, unsigned int count,
 676                           const void *kbuf, const void __user *ubuf)
 677 {
 678         struct pt_regs newregs;
 679         int ret = 0;
 680         unsigned int i, start, num_regs;
 681
 682         /* Calculate the number of AArch32 registers contained in count */
 683         num_regs = count / regset->size;
 684
 685         /* Convert pos into an register number */
 686         start = pos / regset->size;
 687
 688         if (start + num_regs > regset->n)
 689                 return -EIO;
 690
 691         newregs = *task_pt_regs(target);
 692
 693         for (i = 0; i < num_regs; ++i) {
 694                 unsigned int idx = start + i;
 695                 compat_ulong_t reg;
 696
 697                 if (kbuf) {
 698                         memcpy(&reg, kbuf, sizeof(reg));
 699                         kbuf += sizeof(reg);
 700                 } else {
 701                         ret = copy_from_user(&reg, ubuf, sizeof(reg));
 702                         if (ret)
 703                                 return ret;
 704
 705                         ubuf += sizeof(reg);
 706                 }
 707
 708                 switch (idx) {
 709                 case 15:
 710                         newregs.pc = reg;
 711                         break;
 712                 case 16:
 713                         newregs.pstate = reg;
 714                         break;
 715                 case 17:
 716                         newregs.orig_x0 = reg;
 717                         break;
 718                 default:
 719                         newregs.regs[idx] = reg;
 720                 }
 721
 722         }
 723
 724         if (valid_user_regs(&newregs.user_regs))
 725                 *task_pt_regs(target) = newregs;
 726         else
 727                 ret = -EINVAL;
 728
 729         return ret;
 730 }
 731
 732 static int compat_vfp_get(struct task_struct *target,
 733                           const struct user_regset *regset,
 734                           unsigned int pos, unsigned int count,
 735                           void *kbuf, void __user *ubuf)
 736 {
 737         struct user_fpsimd_state *uregs;
 738         compat_ulong_t fpscr;
 739         int ret;
 740
 741         uregs = &target->thread.fpsimd_state.user_fpsimd;
 742
 743         /*
 744          * The VFP registers are packed into the fpsimd_state, so they all sit
 745          * nicely together for us. We just need to create the fpscr separately.
 746          */
 747         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
 748                                   VFP_STATE_SIZE - sizeof(compat_ulong_t));
 749
 750         if (count && !ret) {
 751                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
 752                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
 753                 ret = put_user(fpscr, (compat_ulong_t *)ubuf);
 754         }
 755
 756         return ret;
 757 }
 758
 759 static int compat_vfp_set(struct task_struct *target,
 760                           const struct user_regset *regset,
 761                           unsigned int pos, unsigned int count,
 762                           const void *kbuf, const void __user *ubuf)
 763 {
 764         struct user_fpsimd_state *uregs;
 765         compat_ulong_t fpscr;
 766         int ret;
 767
 768         if (pos + count > VFP_STATE_SIZE)
 769                 return -EIO;
 770
 771         uregs = &target->thread.fpsimd_state.user_fpsimd;
 772
 773         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
 774                                  VFP_STATE_SIZE - sizeof(compat_ulong_t));
 775
 776         if (count && !ret) {
 777                 ret = get_user(fpscr, (compat_ulong_t *)ubuf);
 778                 uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
 779                 uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
 780         }
 781
 782         fpsimd_flush_task_state(target);
 783         return ret;
 784 }
 785
 786 static const struct user_regset aarch32_regsets[] = {
 787         [REGSET_COMPAT_GPR] = {
 788                 .core_note_type = NT_PRSTATUS,
 789                 .n = COMPAT_ELF_NGREG,
 790                 .size = sizeof(compat_elf_greg_t),
 791                 .align = sizeof(compat_elf_greg_t),
 792                 .get = compat_gpr_get,
 793                 .set = compat_gpr_set
 794         },
 795         [REGSET_COMPAT_VFP] = {
 796                 .core_note_type = NT_ARM_VFP,
 797                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
 798                 .size = sizeof(compat_ulong_t),
 799                 .align = sizeof(compat_ulong_t),
 800                 .get = compat_vfp_get,
 801                 .set = compat_vfp_set
 802         },
 803 };
 804
 805 static const struct user_regset_view user_aarch32_view = {
 806         .name = "aarch32", .e_machine = EM_ARM,
 807         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
 808 };
 809
 810 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
 811                                    compat_ulong_t __user *ret)
 812 {
 813         compat_ulong_t tmp;
 814
 815         if (off & 3)
 816                 return -EIO;
 817
 818         if (off == COMPAT_PT_TEXT_ADDR)
 819                 tmp = tsk->mm->start_code;
 820         else if (off == COMPAT_PT_DATA_ADDR)
 821                 tmp = tsk->mm->start_data;
 822         else if (off == COMPAT_PT_TEXT_END_ADDR)
 823                 tmp = tsk->mm->end_code;
 824         else if (off < sizeof(compat_elf_gregset_t))
 825                 return copy_regset_to_user(tsk, &user_aarch32_view,
 826                                            REGSET_COMPAT_GPR, off,
 827                                            sizeof(compat_ulong_t), ret);
 828         else if (off >= COMPAT_USER_SZ)
 829                 return -EIO;
 830         else
 831                 tmp = 0;
 832
 833         return put_user(tmp, ret);
 834 }
 835
 836 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
 837                                     compat_ulong_t val)
 838 {
 839         int ret;
 840         mm_segment_t old_fs = get_fs();
 841
 842         if (off & 3 || off >= COMPAT_USER_SZ)
 843                 return -EIO;
 844
 845         if (off >= sizeof(compat_elf_gregset_t))
 846                 return 0;
 847
 848         set_fs(KERNEL_DS);
 849         ret = copy_regset_from_user(tsk, &user_aarch32_view,
 850                                     REGSET_COMPAT_GPR, off,
 851                                     sizeof(compat_ulong_t),
 852                                     &val);
 853         set_fs(old_fs);
 854
 855         return ret;
 856 }
 857
 858 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 859
 860 /*
 861  * Convert a virtual register number into an index for a thread_info
 862  * breakpoint array. Breakpoints are identified using positive numbers
 863  * whilst watchpoints are negative. The registers are laid out as pairs
 864  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
 865  * Register 0 is reserved for describing resource information.
 866  */
 867 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
 868 {
 869         return (abs(num) - 1) >> 1;
 870 }
 871
 872 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
 873 {
 874         u8 num_brps, num_wrps, debug_arch, wp_len;
 875         u32 reg = 0;
 876
 877         num_brps        = hw_breakpoint_slots(TYPE_INST);
 878         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
 879
 880         debug_arch      = debug_monitors_arch();
 881         wp_len          = 8;
 882         reg             |= debug_arch;
 883         reg             <<= 8;
 884         reg             |= wp_len;
 885         reg             <<= 8;
 886         reg             |= num_wrps;
 887         reg             <<= 8;
 888         reg             |= num_brps;
 889
 890         *kdata = reg;
 891         return 0;
 892 }
 893
 894 static int compat_ptrace_hbp_get(unsigned int note_type,
 895                                  struct task_struct *tsk,
 896                                  compat_long_t num,
 897                                  u32 *kdata)
 898 {
 899         u64 addr = 0;
 900         u32 ctrl = 0;
 901
 902         int err, idx = compat_ptrace_hbp_num_to_idx(num);;
 903
 904         if (num & 1) {
 905                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
 906                 *kdata = (u32)addr;
 907         } else {
 908                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
 909                 *kdata = ctrl;
 910         }
 911
 912         return err;
 913 }
 914
 915 static int compat_ptrace_hbp_set(unsigned int note_type,
 916                                  struct task_struct *tsk,
 917                                  compat_long_t num,
 918                                  u32 *kdata)
 919 {
 920         u64 addr;
 921         u32 ctrl;
 922
 923         int err, idx = compat_ptrace_hbp_num_to_idx(num);
 924
 925         if (num & 1) {
 926                 addr = *kdata;
 927                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
 928         } else {
 929                 ctrl = *kdata;
 930                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
 931         }
 932
 933         return err;
 934 }
 935
 936 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
 937                                     compat_ulong_t __user *data)
 938 {
 939         int ret;
 940         u32 kdata;
 941         mm_segment_t old_fs = get_fs();
 942
 943         set_fs(KERNEL_DS);
 944         /* Watchpoint */
 945         if (num < 0) {
 946                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
 947         /* Resource info */
 948         } else if (num == 0) {
 949                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
 950         /* Breakpoint */
 951         } else {
 952                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
 953         }
 954         set_fs(old_fs);
 955
 956         if (!ret)
 957                 ret = put_user(kdata, data);
 958
 959         return ret;
 960 }
 961
 962 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
 963                                     compat_ulong_t __user *data)
 964 {
 965         int ret;
 966         u32 kdata = 0;
 967         mm_segment_t old_fs = get_fs();
 968
 969         if (num == 0)
 970                 return 0;
 971
 972         ret = get_user(kdata, data);
 973         if (ret)
 974                 return ret;
 975
 976         set_fs(KERNEL_DS);
 977         if (num < 0)
 978                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
 979         else
 980                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
 981         set_fs(old_fs);
 982
 983         return ret;
 984 }
 985 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 986
 987 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 988                         compat_ulong_t caddr, compat_ulong_t cdata)
 989 {
 990         unsigned long addr = caddr;
 991         unsigned long data = cdata;
 992         void __user *datap = compat_ptr(data);
 993         int ret;
 994
 995         switch (request) {
 996                 case PTRACE_PEEKUSR:
 997                         ret = compat_ptrace_read_user(child, addr, datap);
 998                         break;
 999
1000                 case PTRACE_POKEUSR:
1001                         ret = compat_ptrace_write_user(child, addr, data);
1002                         break;
1003
1004                 case COMPAT_PTRACE_GETREGS:
1005                         ret = copy_regset_to_user(child,
1006                                                   &user_aarch32_view,
1007                                                   REGSET_COMPAT_GPR,
1008                                                   0, sizeof(compat_elf_gregset_t),
1009                                                   datap);
1010                         break;
1011
1012                 case COMPAT_PTRACE_SETREGS:
1013                         ret = copy_regset_from_user(child,
1014                                                     &user_aarch32_view,
1015                                                     REGSET_COMPAT_GPR,
1016                                                     0, sizeof(compat_elf_gregset_t),
1017                                                     datap);
1018                         break;
1019
1020                 case COMPAT_PTRACE_GET_THREAD_AREA:
1021                         ret = put_user((compat_ulong_t)child->thread.tp_value,
1022                                        (compat_ulong_t __user *)datap);
1023                         break;
1024
1025                 case COMPAT_PTRACE_SET_SYSCALL:
1026                         task_pt_regs(child)->syscallno = data;
1027                         ret = 0;
1028                         break;
1029
1030                 case COMPAT_PTRACE_GETVFPREGS:
1031                         ret = copy_regset_to_user(child,
1032                                                   &user_aarch32_view,
1033                                                   REGSET_COMPAT_VFP,
1034                                                   0, VFP_STATE_SIZE,
1035                                                   datap);
1036                         break;
1037
1038                 case COMPAT_PTRACE_SETVFPREGS:
1039                         ret = copy_regset_from_user(child,
1040                                                     &user_aarch32_view,
1041                                                     REGSET_COMPAT_VFP,
1042                                                     0, VFP_STATE_SIZE,
1043                                                     datap);
1044                         break;
1045
1046 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1047                 case COMPAT_PTRACE_GETHBPREGS:
1048                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1049                         break;
1050
1051                 case COMPAT_PTRACE_SETHBPREGS:
1052                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1053                         break;
1054 #endif
1055
1056                 default:
1057                         ret = compat_ptrace_request(child, request, addr,
1058                                                     data);
1059                         break;
1060         }
1061
1062         return ret;
1063 }
1064 #endif /* CONFIG_COMPAT */
1065
1066 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1067 {
1068 #ifdef CONFIG_COMPAT
1069         if (is_compat_thread(task_thread_info(task)))
1070                 return &user_aarch32_view;
1071 #endif
1072         return &user_aarch64_view;
1073 }
1074
1075 long arch_ptrace(struct task_struct *child, long request,
1076                  unsigned long addr, unsigned long data)
1077 {
1078         return ptrace_request(child, request, addr, data);
1079 }
1080
1081 enum ptrace_syscall_dir {
1082         PTRACE_SYSCALL_ENTER = 0,
1083         PTRACE_SYSCALL_EXIT,
1084 };
1085
1086 static void tracehook_report_syscall(struct pt_regs *regs,
1087                                      enum ptrace_syscall_dir dir)
1088 {
1089         int regno;
1090         unsigned long saved_reg;
1091
1092         /*
1093          * A scratch register (ip(r12) on AArch32, x7 on AArch64) is
1094          * used to denote syscall entry/exit:
1095          */
1096         regno = (is_compat_task() ? 12 : 7);
1097         saved_reg = regs->regs[regno];
1098         regs->regs[regno] = dir;
1099
1100         if (dir == PTRACE_SYSCALL_EXIT)
1101                 tracehook_report_syscall_exit(regs, 0);
1102         else if (tracehook_report_syscall_entry(regs))
1103                 regs->syscallno = ~0UL;
1104
1105         regs->regs[regno] = saved_reg;
1106 }
1107
1108 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
1109 {
1110         if (test_thread_flag(TIF_SYSCALL_TRACE))
1111                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1112
1113         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1114                 trace_sys_enter(regs, regs->syscallno);
1115
1116         return regs->syscallno;
1117 }
1118
1119 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
1120 {
1121         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1122                 trace_sys_exit(regs, regs_return_value(regs));
1123
1124         if (test_thread_flag(TIF_SYSCALL_TRACE))
1125                 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1126 }