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
  89         for (i = 0; i < ARM_MAX_WRP; ++i) {
  90                 if (current->thread.debug.hbp_watch[i] == bp) {
  91                         info.si_errno = -((i << 1) + 1);
  92                         break;
  93                 }
  94         }
  95
  96 send_sig:
  97 #endif
  98         force_sig_info(SIGTRAP, &info, current);
  99 }
 100
 101 /*
 102  * Unregister breakpoints from this task and reset the pointers in
 103  * the thread_struct.
 104  */
 105 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 106 {
 107         int i;
 108         struct thread_struct *t = &tsk->thread;
 109
 110         for (i = 0; i < ARM_MAX_BRP; i++) {
 111                 if (t->debug.hbp_break[i]) {
 112                         unregister_hw_breakpoint(t->debug.hbp_break[i]);
 113                         t->debug.hbp_break[i] = NULL;
 114                 }
 115         }
 116
 117         for (i = 0; i < ARM_MAX_WRP; i++) {
 118                 if (t->debug.hbp_watch[i]) {
 119                         unregister_hw_breakpoint(t->debug.hbp_watch[i]);
 120                         t->debug.hbp_watch[i] = NULL;
 121                 }
 122         }
 123 }
 124
 125 void ptrace_hw_copy_thread(struct task_struct *tsk)
 126 {
 127         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 128 }
 129
 130 static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
 131                                                struct task_struct *tsk,
 132                                                unsigned long idx)
 133 {
 134         struct perf_event *bp = ERR_PTR(-EINVAL);
 135
 136         switch (note_type) {
 137         case NT_ARM_HW_BREAK:
 138                 if (idx < ARM_MAX_BRP)
 139                         bp = tsk->thread.debug.hbp_break[idx];
 140                 break;
 141         case NT_ARM_HW_WATCH:
 142                 if (idx < ARM_MAX_WRP)
 143                         bp = tsk->thread.debug.hbp_watch[idx];
 144                 break;
 145         }
 146
 147         return bp;
 148 }
 149
 150 static int ptrace_hbp_set_event(unsigned int note_type,
 151                                 struct task_struct *tsk,
 152                                 unsigned long idx,
 153                                 struct perf_event *bp)
 154 {
 155         int err = -EINVAL;
 156
 157         switch (note_type) {
 158         case NT_ARM_HW_BREAK:
 159                 if (idx < ARM_MAX_BRP) {
 160                         tsk->thread.debug.hbp_break[idx] = bp;
 161                         err = 0;
 162                 }
 163                 break;
 164         case NT_ARM_HW_WATCH:
 165                 if (idx < ARM_MAX_WRP) {
 166                         tsk->thread.debug.hbp_watch[idx] = bp;
 167                         err = 0;
 168                 }
 169                 break;
 170         }
 171
 172         return err;
 173 }
 174
 175 static struct perf_event *ptrace_hbp_create(unsigned int note_type,
 176                                             struct task_struct *tsk,
 177                                             unsigned long idx)
 178 {
 179         struct perf_event *bp;
 180         struct perf_event_attr attr;
 181         int err, type;
 182
 183         switch (note_type) {
 184         case NT_ARM_HW_BREAK:
 185                 type = HW_BREAKPOINT_X;
 186                 break;
 187         case NT_ARM_HW_WATCH:
 188                 type = HW_BREAKPOINT_RW;
 189                 break;
 190         default:
 191                 return ERR_PTR(-EINVAL);
 192         }
 193
 194         ptrace_breakpoint_init(&attr);
 195
 196         /*
 197          * Initialise fields to sane defaults
 198          * (i.e. values that will pass validation).
 199          */
 200         attr.bp_addr    = 0;
 201         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 202         attr.bp_type    = type;
 203         attr.disabled   = 1;
 204
 205         bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk);
 206         if (IS_ERR(bp))
 207                 return bp;
 208
 209         err = ptrace_hbp_set_event(note_type, tsk, idx, bp);
 210         if (err)
 211                 return ERR_PTR(err);
 212
 213         return bp;
 214 }
 215
 216 static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
 217                                      struct arch_hw_breakpoint_ctrl ctrl,
 218                                      struct perf_event_attr *attr)
 219 {
 220         int err, len, type, disabled = !ctrl.enabled;
 221
 222         attr->disabled = disabled;
 223         if (disabled)
 224                 return 0;
 225
 226         err = arch_bp_generic_fields(ctrl, &len, &type);
 227         if (err)
 228                 return err;
 229
 230         switch (note_type) {
 231         case NT_ARM_HW_BREAK:
 232                 if ((type & HW_BREAKPOINT_X) != type)
 233                         return -EINVAL;
 234                 break;
 235         case NT_ARM_HW_WATCH:
 236                 if ((type & HW_BREAKPOINT_RW) != type)
 237                         return -EINVAL;
 238                 break;
 239         default:
 240                 return -EINVAL;
 241         }
 242
 243         attr->bp_len    = len;
 244         attr->bp_type   = type;
 245
 246         return 0;
 247 }
 248
 249 static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info)
 250 {
 251         u8 num;
 252         u32 reg = 0;
 253
 254         switch (note_type) {
 255         case NT_ARM_HW_BREAK:
 256                 num = hw_breakpoint_slots(TYPE_INST);
 257                 break;
 258         case NT_ARM_HW_WATCH:
 259                 num = hw_breakpoint_slots(TYPE_DATA);
 260                 break;
 261         default:
 262                 return -EINVAL;
 263         }
 264
 265         reg |= debug_monitors_arch();
 266         reg <<= 8;
 267         reg |= num;
 268
 269         *info = reg;
 270         return 0;
 271 }
 272
 273 static int ptrace_hbp_get_ctrl(unsigned int note_type,
 274                                struct task_struct *tsk,
 275                                unsigned long idx,
 276                                u32 *ctrl)
 277 {
 278         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 279
 280         if (IS_ERR(bp))
 281                 return PTR_ERR(bp);
 282
 283         *ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0;
 284         return 0;
 285 }
 286
 287 static int ptrace_hbp_get_addr(unsigned int note_type,
 288                                struct task_struct *tsk,
 289                                unsigned long idx,
 290                                u64 *addr)
 291 {
 292         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 293
 294         if (IS_ERR(bp))
 295                 return PTR_ERR(bp);
 296
 297         *addr = bp ? bp->attr.bp_addr : 0;
 298         return 0;
 299 }
 300
 301 static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type,
 302                                                         struct task_struct *tsk,
 303                                                         unsigned long idx)
 304 {
 305         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 306
 307         if (!bp)
 308                 bp = ptrace_hbp_create(note_type, tsk, idx);
 309
 310         return bp;
 311 }
 312
 313 static int ptrace_hbp_set_ctrl(unsigned int note_type,
 314                                struct task_struct *tsk,
 315                                unsigned long idx,
 316                                u32 uctrl)
 317 {
 318         int err;
 319         struct perf_event *bp;
 320         struct perf_event_attr attr;
 321         struct arch_hw_breakpoint_ctrl ctrl;
 322
 323         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 324         if (IS_ERR(bp)) {
 325                 err = PTR_ERR(bp);
 326                 return err;
 327         }
 328
 329         attr = bp->attr;
 330         decode_ctrl_reg(uctrl, &ctrl);
 331         err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
 332         if (err)
 333                 return err;
 334
 335         return modify_user_hw_breakpoint(bp, &attr);
 336 }
 337
 338 static int ptrace_hbp_set_addr(unsigned int note_type,
 339                                struct task_struct *tsk,
 340                                unsigned long idx,
 341                                u64 addr)
 342 {
 343         int err;
 344         struct perf_event *bp;
 345         struct perf_event_attr attr;
 346
 347         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 348         if (IS_ERR(bp)) {
 349                 err = PTR_ERR(bp);
 350                 return err;
 351         }
 352
 353         attr = bp->attr;
 354         attr.bp_addr = addr;
 355         err = modify_user_hw_breakpoint(bp, &attr);
 356         return err;
 357 }
 358
 359 #define PTRACE_HBP_ADDR_SZ      sizeof(u64)
 360 #define PTRACE_HBP_CTRL_SZ      sizeof(u32)
 361 #define PTRACE_HBP_PAD_SZ       sizeof(u32)
 362
 363 static int hw_break_get(struct task_struct *target,
 364                         const struct user_regset *regset,
 365                         unsigned int pos, unsigned int count,
 366                         void *kbuf, void __user *ubuf)
 367 {
 368         unsigned int note_type = regset->core_note_type;
 369         int ret, idx = 0, offset, limit;
 370         u32 info, ctrl;
 371         u64 addr;
 372
 373         /* Resource info */
 374         ret = ptrace_hbp_get_resource_info(note_type, &info);
 375         if (ret)
 376                 return ret;
 377
 378         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0,
 379                                   sizeof(info));
 380         if (ret)
 381                 return ret;
 382
 383         /* Pad */
 384         offset = offsetof(struct user_hwdebug_state, pad);
 385         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, offset,
 386                                        offset + PTRACE_HBP_PAD_SZ);
 387         if (ret)
 388                 return ret;
 389
 390         /* (address, ctrl) registers */
 391         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 392         limit = regset->n * regset->size;
 393         while (count && offset < limit) {
 394                 ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
 395                 if (ret)
 396                         return ret;
 397                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr,
 398                                           offset, offset + PTRACE_HBP_ADDR_SZ);
 399                 if (ret)
 400                         return ret;
 401                 offset += PTRACE_HBP_ADDR_SZ;
 402
 403                 ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
 404                 if (ret)
 405                         return ret;
 406                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl,
 407                                           offset, offset + PTRACE_HBP_CTRL_SZ);
 408                 if (ret)
 409                         return ret;
 410                 offset += PTRACE_HBP_CTRL_SZ;
 411
 412                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 413                                                offset,
 414                                                offset + PTRACE_HBP_PAD_SZ);
 415                 if (ret)
 416                         return ret;
 417                 offset += PTRACE_HBP_PAD_SZ;
 418                 idx++;
 419         }
 420
 421         return 0;
 422 }
 423
 424 static int hw_break_set(struct task_struct *target,
 425                         const struct user_regset *regset,
 426                         unsigned int pos, unsigned int count,
 427                         const void *kbuf, const void __user *ubuf)
 428 {
 429         unsigned int note_type = regset->core_note_type;
 430         int ret, idx = 0, offset, limit;
 431         u32 ctrl;
 432         u64 addr;
 433
 434         /* Resource info and pad */
 435         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 436         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset);
 437         if (ret)
 438                 return ret;
 439
 440         /* (address, ctrl) registers */
 441         limit = regset->n * regset->size;
 442         while (count && offset < limit) {
 443                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
 444                                          offset, offset + PTRACE_HBP_ADDR_SZ);
 445                 if (ret)
 446                         return ret;
 447                 ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
 448                 if (ret)
 449                         return ret;
 450                 offset += PTRACE_HBP_ADDR_SZ;
 451
 452                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
 453                                          offset, offset + PTRACE_HBP_CTRL_SZ);
 454                 if (ret)
 455                         return ret;
 456                 ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
 457                 if (ret)
 458                         return ret;
 459                 offset += PTRACE_HBP_CTRL_SZ;
 460
 461                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 462                                                 offset,
 463                                                 offset + PTRACE_HBP_PAD_SZ);
 464                 if (ret)
 465                         return ret;
 466                 offset += PTRACE_HBP_PAD_SZ;
 467                 idx++;
 468         }
 469
 470         return 0;
 471 }
 472 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 473
 474 static int gpr_get(struct task_struct *target,
 475                    const struct user_regset *regset,
 476                    unsigned int pos, unsigned int count,
 477                    void *kbuf, void __user *ubuf)
 478 {
 479         struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
 480         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 481 }
 482
 483 static int gpr_set(struct task_struct *target, const struct user_regset *regset,
 484                    unsigned int pos, unsigned int count,
 485                    const void *kbuf, const void __user *ubuf)
 486 {
 487         int ret;
 488         struct user_pt_regs newregs;
 489
 490         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
 491         if (ret)
 492                 return ret;
 493
 494         if (!valid_user_regs(&newregs))
 495                 return -EINVAL;
 496
 497         task_pt_regs(target)->user_regs = newregs;
 498         return 0;
 499 }
 500
 501 /*
 502  * TODO: update fp accessors for lazy context switching (sync/flush hwstate)
 503  */
 504 static int fpr_get(struct task_struct *target, const struct user_regset *regset,
 505                    unsigned int pos, unsigned int count,
 506                    void *kbuf, void __user *ubuf)
 507 {
 508         struct user_fpsimd_state *uregs;
 509         uregs = &target->thread.fpsimd_state.user_fpsimd;
 510         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 511 }
 512
 513 static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 514                    unsigned int pos, unsigned int count,
 515                    const void *kbuf, const void __user *ubuf)
 516 {
 517         int ret;
 518         struct user_fpsimd_state newstate;
 519
 520         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1);
 521         if (ret)
 522                 return ret;
 523
 524         target->thread.fpsimd_state.user_fpsimd = newstate;
 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                                 ret = -EFAULT;
 665                                 break;
 666                         }
 667
 668                         ubuf += sizeof(reg);
 669                 }
 670         }
 671
 672         return ret;
 673 }
 674
 675 static int compat_gpr_set(struct task_struct *target,
 676                           const struct user_regset *regset,
 677                           unsigned int pos, unsigned int count,
 678                           const void *kbuf, const void __user *ubuf)
 679 {
 680         struct pt_regs newregs;
 681         int ret = 0;
 682         unsigned int i, start, num_regs;
 683
 684         /* Calculate the number of AArch32 registers contained in count */
 685         num_regs = count / regset->size;
 686
 687         /* Convert pos into an register number */
 688         start = pos / regset->size;
 689
 690         if (start + num_regs > regset->n)
 691                 return -EIO;
 692
 693         newregs = *task_pt_regs(target);
 694
 695         for (i = 0; i < num_regs; ++i) {
 696                 unsigned int idx = start + i;
 697                 compat_ulong_t reg;
 698
 699                 if (kbuf) {
 700                         memcpy(&reg, kbuf, sizeof(reg));
 701                         kbuf += sizeof(reg);
 702                 } else {
 703                         ret = copy_from_user(&reg, ubuf, sizeof(reg));
 704                         if (ret) {
 705                                 ret = -EFAULT;
 706                                 break;
 707                         }
 708
 709                         ubuf += sizeof(reg);
 710                 }
 711
 712                 switch (idx) {
 713                 case 15:
 714                         newregs.pc = reg;
 715                         break;
 716                 case 16:
 717                         newregs.pstate = reg;
 718                         break;
 719                 case 17:
 720                         newregs.orig_x0 = reg;
 721                         break;
 722                 default:
 723                         newregs.regs[idx] = reg;
 724                 }
 725
 726         }
 727
 728         if (valid_user_regs(&newregs.user_regs))
 729                 *task_pt_regs(target) = newregs;
 730         else
 731                 ret = -EINVAL;
 732
 733         return ret;
 734 }
 735
 736 static int compat_vfp_get(struct task_struct *target,
 737                           const struct user_regset *regset,
 738                           unsigned int pos, unsigned int count,
 739                           void *kbuf, void __user *ubuf)
 740 {
 741         struct user_fpsimd_state *uregs;
 742         compat_ulong_t fpscr;
 743         int ret;
 744
 745         uregs = &target->thread.fpsimd_state.user_fpsimd;
 746
 747         /*
 748          * The VFP registers are packed into the fpsimd_state, so they all sit
 749          * nicely together for us. We just need to create the fpscr separately.
 750          */
 751         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
 752                                   VFP_STATE_SIZE - sizeof(compat_ulong_t));
 753
 754         if (count && !ret) {
 755                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
 756                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
 757                 ret = put_user(fpscr, (compat_ulong_t *)ubuf);
 758         }
 759
 760         return ret;
 761 }
 762
 763 static int compat_vfp_set(struct task_struct *target,
 764                           const struct user_regset *regset,
 765                           unsigned int pos, unsigned int count,
 766                           const void *kbuf, const void __user *ubuf)
 767 {
 768         struct user_fpsimd_state *uregs;
 769         compat_ulong_t fpscr;
 770         int ret;
 771
 772         if (pos + count > VFP_STATE_SIZE)
 773                 return -EIO;
 774
 775         uregs = &target->thread.fpsimd_state.user_fpsimd;
 776
 777         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
 778                                  VFP_STATE_SIZE - sizeof(compat_ulong_t));
 779
 780         if (count && !ret) {
 781                 ret = get_user(fpscr, (compat_ulong_t *)ubuf);
 782                 uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
 783                 uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
 784         }
 785
 786         return ret;
 787 }
 788
 789 static const struct user_regset aarch32_regsets[] = {
 790         [REGSET_COMPAT_GPR] = {
 791                 .core_note_type = NT_PRSTATUS,
 792                 .n = COMPAT_ELF_NGREG,
 793                 .size = sizeof(compat_elf_greg_t),
 794                 .align = sizeof(compat_elf_greg_t),
 795                 .get = compat_gpr_get,
 796                 .set = compat_gpr_set
 797         },
 798         [REGSET_COMPAT_VFP] = {
 799                 .core_note_type = NT_ARM_VFP,
 800                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
 801                 .size = sizeof(compat_ulong_t),
 802                 .align = sizeof(compat_ulong_t),
 803                 .get = compat_vfp_get,
 804                 .set = compat_vfp_set
 805         },
 806 };
 807
 808 static const struct user_regset_view user_aarch32_view = {
 809         .name = "aarch32", .e_machine = EM_ARM,
 810         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
 811 };
 812
 813 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
 814                                    compat_ulong_t __user *ret)
 815 {
 816         compat_ulong_t tmp;
 817
 818         if (off & 3)
 819                 return -EIO;
 820
 821         if (off == COMPAT_PT_TEXT_ADDR)
 822                 tmp = tsk->mm->start_code;
 823         else if (off == COMPAT_PT_DATA_ADDR)
 824                 tmp = tsk->mm->start_data;
 825         else if (off == COMPAT_PT_TEXT_END_ADDR)
 826                 tmp = tsk->mm->end_code;
 827         else if (off < sizeof(compat_elf_gregset_t))
 828                 return copy_regset_to_user(tsk, &user_aarch32_view,
 829                                            REGSET_COMPAT_GPR, off,
 830                                            sizeof(compat_ulong_t), ret);
 831         else if (off >= COMPAT_USER_SZ)
 832                 return -EIO;
 833         else
 834                 tmp = 0;
 835
 836         return put_user(tmp, ret);
 837 }
 838
 839 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
 840                                     compat_ulong_t val)
 841 {
 842         int ret;
 843         mm_segment_t old_fs = get_fs();
 844
 845         if (off & 3 || off >= COMPAT_USER_SZ)
 846                 return -EIO;
 847
 848         if (off >= sizeof(compat_elf_gregset_t))
 849                 return 0;
 850
 851         set_fs(KERNEL_DS);
 852         ret = copy_regset_from_user(tsk, &user_aarch32_view,
 853                                     REGSET_COMPAT_GPR, off,
 854                                     sizeof(compat_ulong_t),
 855                                     &val);
 856         set_fs(old_fs);
 857
 858         return ret;
 859 }
 860
 861 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 862
 863 /*
 864  * Convert a virtual register number into an index for a thread_info
 865  * breakpoint array. Breakpoints are identified using positive numbers
 866  * whilst watchpoints are negative. The registers are laid out as pairs
 867  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
 868  * Register 0 is reserved for describing resource information.
 869  */
 870 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
 871 {
 872         return (abs(num) - 1) >> 1;
 873 }
 874
 875 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
 876 {
 877         u8 num_brps, num_wrps, debug_arch, wp_len;
 878         u32 reg = 0;
 879
 880         num_brps        = hw_breakpoint_slots(TYPE_INST);
 881         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
 882
 883         debug_arch      = debug_monitors_arch();
 884         wp_len          = 8;
 885         reg             |= debug_arch;
 886         reg             <<= 8;
 887         reg             |= wp_len;
 888         reg             <<= 8;
 889         reg             |= num_wrps;
 890         reg             <<= 8;
 891         reg             |= num_brps;
 892
 893         *kdata = reg;
 894         return 0;
 895 }
 896
 897 static int compat_ptrace_hbp_get(unsigned int note_type,
 898                                  struct task_struct *tsk,
 899                                  compat_long_t num,
 900                                  u32 *kdata)
 901 {
 902         u64 addr = 0;
 903         u32 ctrl = 0;
 904
 905         int err, idx = compat_ptrace_hbp_num_to_idx(num);;
 906
 907         if (num & 1) {
 908                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
 909                 *kdata = (u32)addr;
 910         } else {
 911                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
 912                 *kdata = ctrl;
 913         }
 914
 915         return err;
 916 }
 917
 918 static int compat_ptrace_hbp_set(unsigned int note_type,
 919                                  struct task_struct *tsk,
 920                                  compat_long_t num,
 921                                  u32 *kdata)
 922 {
 923         u64 addr;
 924         u32 ctrl;
 925
 926         int err, idx = compat_ptrace_hbp_num_to_idx(num);
 927
 928         if (num & 1) {
 929                 addr = *kdata;
 930                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
 931         } else {
 932                 ctrl = *kdata;
 933                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
 934         }
 935
 936         return err;
 937 }
 938
 939 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
 940                                     compat_ulong_t __user *data)
 941 {
 942         int ret;
 943         u32 kdata;
 944         mm_segment_t old_fs = get_fs();
 945
 946         set_fs(KERNEL_DS);
 947         /* Watchpoint */
 948         if (num < 0) {
 949                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
 950         /* Resource info */
 951         } else if (num == 0) {
 952                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
 953         /* Breakpoint */
 954         } else {
 955                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
 956         }
 957         set_fs(old_fs);
 958
 959         if (!ret)
 960                 ret = put_user(kdata, data);
 961
 962         return ret;
 963 }
 964
 965 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
 966                                     compat_ulong_t __user *data)
 967 {
 968         int ret;
 969         u32 kdata = 0;
 970         mm_segment_t old_fs = get_fs();
 971
 972         if (num == 0)
 973                 return 0;
 974
 975         ret = get_user(kdata, data);
 976         if (ret)
 977                 return ret;
 978
 979         set_fs(KERNEL_DS);
 980         if (num < 0)
 981                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
 982         else
 983                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
 984         set_fs(old_fs);
 985
 986         return ret;
 987 }
 988 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 989
 990 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 991                         compat_ulong_t caddr, compat_ulong_t cdata)
 992 {
 993         unsigned long addr = caddr;
 994         unsigned long data = cdata;
 995         void __user *datap = compat_ptr(data);
 996         int ret;
 997
 998         switch (request) {
 999                 case PTRACE_PEEKUSR:
1000                         ret = compat_ptrace_read_user(child, addr, datap);
1001                         break;
1002
1003                 case PTRACE_POKEUSR:
1004                         ret = compat_ptrace_write_user(child, addr, data);
1005                         break;
1006
1007                 case COMPAT_PTRACE_GETREGS:
1008                         ret = copy_regset_to_user(child,
1009                                                   &user_aarch32_view,
1010                                                   REGSET_COMPAT_GPR,
1011                                                   0, sizeof(compat_elf_gregset_t),
1012                                                   datap);
1013                         break;
1014
1015                 case COMPAT_PTRACE_SETREGS:
1016                         ret = copy_regset_from_user(child,
1017                                                     &user_aarch32_view,
1018                                                     REGSET_COMPAT_GPR,
1019                                                     0, sizeof(compat_elf_gregset_t),
1020                                                     datap);
1021                         break;
1022
1023                 case COMPAT_PTRACE_GET_THREAD_AREA:
1024                         ret = put_user((compat_ulong_t)child->thread.tp_value,
1025                                        (compat_ulong_t __user *)datap);
1026                         break;
1027
1028                 case COMPAT_PTRACE_SET_SYSCALL:
1029                         task_pt_regs(child)->syscallno = data;
1030                         ret = 0;
1031                         break;
1032
1033                 case COMPAT_PTRACE_GETVFPREGS:
1034                         ret = copy_regset_to_user(child,
1035                                                   &user_aarch32_view,
1036                                                   REGSET_COMPAT_VFP,
1037                                                   0, VFP_STATE_SIZE,
1038                                                   datap);
1039                         break;
1040
1041                 case COMPAT_PTRACE_SETVFPREGS:
1042                         ret = copy_regset_from_user(child,
1043                                                     &user_aarch32_view,
1044                                                     REGSET_COMPAT_VFP,
1045                                                     0, VFP_STATE_SIZE,
1046                                                     datap);
1047                         break;
1048
1049 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1050                 case COMPAT_PTRACE_GETHBPREGS:
1051                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1052                         break;
1053
1054                 case COMPAT_PTRACE_SETHBPREGS:
1055                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1056                         break;
1057 #endif
1058
1059                 default:
1060                         ret = compat_ptrace_request(child, request, addr,
1061                                                     data);
1062                         break;
1063         }
1064
1065         return ret;
1066 }
1067 #endif /* CONFIG_COMPAT */
1068
1069 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1070 {
1071 #ifdef CONFIG_COMPAT
1072         if (is_compat_thread(task_thread_info(task)))
1073                 return &user_aarch32_view;
1074 #endif
1075         return &user_aarch64_view;
1076 }
1077
1078 long arch_ptrace(struct task_struct *child, long request,
1079                  unsigned long addr, unsigned long data)
1080 {
1081         return ptrace_request(child, request, addr, data);
1082 }
1083
1084 enum ptrace_syscall_dir {
1085         PTRACE_SYSCALL_ENTER = 0,
1086         PTRACE_SYSCALL_EXIT,
1087 };
1088
1089 static void tracehook_report_syscall(struct pt_regs *regs,
1090                                      enum ptrace_syscall_dir dir)
1091 {
1092         int regno;
1093         unsigned long saved_reg;
1094
1095         /*
1096          * A scratch register (ip(r12) on AArch32, x7 on AArch64) is
1097          * used to denote syscall entry/exit:
1098          */
1099         regno = (is_compat_task() ? 12 : 7);
1100         saved_reg = regs->regs[regno];
1101         regs->regs[regno] = dir;
1102
1103         if (dir == PTRACE_SYSCALL_EXIT)
1104                 tracehook_report_syscall_exit(regs, 0);
1105         else if (tracehook_report_syscall_entry(regs))
1106                 regs->syscallno = ~0UL;
1107
1108         regs->regs[regno] = saved_reg;
1109 }
1110
1111 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
1112 {
1113         if (test_thread_flag(TIF_SYSCALL_TRACE))
1114                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1115
1116         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1117                 trace_sys_enter(regs, regs->syscallno);
1118
1119         return regs->syscallno;
1120 }
1121
1122 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
1123 {
1124         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1125                 trace_sys_exit(regs, regs_return_value(regs));
1126
1127         if (test_thread_flag(TIF_SYSCALL_TRACE))
1128                 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1129 }