arch/arm64/kernel/ptrace.c

   1 /*
   2  * Based on arch/arm/kernel/ptrace.c
   3  *
   4  * By Ross Biro 1/23/92
   5  * edited by Linus Torvalds
   6  * ARM modifications Copyright (C) 2000 Russell King
   7  * Copyright (C) 2012 ARM Ltd.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <linux/audit.h>
  23 #include <linux/compat.h>
  24 #include <linux/kernel.h>
  25 #include <linux/sched.h>
  26 #include <linux/mm.h>
  27 #include <linux/smp.h>
  28 #include <linux/ptrace.h>
  29 #include <linux/user.h>
  30 #include <linux/security.h>
  31 #include <linux/init.h>
  32 #include <linux/signal.h>
  33 #include <linux/uaccess.h>
  34 #include <linux/perf_event.h>
  35 #include <linux/hw_breakpoint.h>
  36 #include <linux/regset.h>
  37 #include <linux/tracehook.h>
  38 #include <linux/elf.h>
  39
  40 #include <asm/compat.h>
  41 #include <asm/debug-monitors.h>
  42 #include <asm/pgtable.h>
  43 #include <asm/syscall.h>
  44 #include <asm/traps.h>
  45 #include <asm/system_misc.h>
  46
  47 /*
  48  * TODO: does not yet catch signals sent when the child dies.
  49  * in exit.c or in signal.c.
  50  */
  51
  52 /*
  53  * Called by kernel/ptrace.c when detaching..
  54  */
  55 void ptrace_disable(struct task_struct *child)
  56 {
  57 }
  58
  59 #ifdef CONFIG_HAVE_HW_BREAKPOINT
  60 /*
  61  * Handle hitting a HW-breakpoint.
  62  */
  63 static void ptrace_hbptriggered(struct perf_event *bp,
  64                                 struct perf_sample_data *data,
  65                                 struct pt_regs *regs)
  66 {
  67         struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
  68         siginfo_t info = {
  69                 .si_signo       = SIGTRAP,
  70                 .si_errno       = 0,
  71                 .si_code        = TRAP_HWBKPT,
  72                 .si_addr        = (void __user *)(bkpt->trigger),
  73         };
  74
  75 #ifdef CONFIG_COMPAT
  76         int i;
  77
  78         if (!is_compat_task())
  79                 goto send_sig;
  80
  81         for (i = 0; i < ARM_MAX_BRP; ++i) {
  82                 if (current->thread.debug.hbp_break[i] == bp) {
  83                         info.si_errno = (i << 1) + 1;
  84                         break;
  85                 }
  86         }
  87         for (i = ARM_MAX_BRP; i < ARM_MAX_HBP_SLOTS && !bp; ++i) {
  88                 if (current->thread.debug.hbp_watch[i] == bp) {
  89                         info.si_errno = -((i << 1) + 1);
  90                         break;
  91                 }
  92         }
  93
  94 send_sig:
  95 #endif
  96         force_sig_info(SIGTRAP, &info, current);
  97 }
  98
  99 /*
 100  * Unregister breakpoints from this task and reset the pointers in
 101  * the thread_struct.
 102  */
 103 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 104 {
 105         int i;
 106         struct thread_struct *t = &tsk->thread;
 107
 108         for (i = 0; i < ARM_MAX_BRP; i++) {
 109                 if (t->debug.hbp_break[i]) {
 110                         unregister_hw_breakpoint(t->debug.hbp_break[i]);
 111                         t->debug.hbp_break[i] = NULL;
 112                 }
 113         }
 114
 115         for (i = 0; i < ARM_MAX_WRP; i++) {
 116                 if (t->debug.hbp_watch[i]) {
 117                         unregister_hw_breakpoint(t->debug.hbp_watch[i]);
 118                         t->debug.hbp_watch[i] = NULL;
 119                 }
 120         }
 121 }
 122
 123 void ptrace_hw_copy_thread(struct task_struct *tsk)
 124 {
 125         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 126 }
 127
 128 static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
 129                                                struct task_struct *tsk,
 130                                                unsigned long idx)
 131 {
 132         struct perf_event *bp = ERR_PTR(-EINVAL);
 133
 134         switch (note_type) {
 135         case NT_ARM_HW_BREAK:
 136                 if (idx < ARM_MAX_BRP)
 137                         bp = tsk->thread.debug.hbp_break[idx];
 138                 break;
 139         case NT_ARM_HW_WATCH:
 140                 if (idx < ARM_MAX_WRP)
 141                         bp = tsk->thread.debug.hbp_watch[idx];
 142                 break;
 143         }
 144
 145         return bp;
 146 }
 147
 148 static int ptrace_hbp_set_event(unsigned int note_type,
 149                                 struct task_struct *tsk,
 150                                 unsigned long idx,
 151                                 struct perf_event *bp)
 152 {
 153         int err = -EINVAL;
 154
 155         switch (note_type) {
 156         case NT_ARM_HW_BREAK:
 157                 if (idx < ARM_MAX_BRP) {
 158                         tsk->thread.debug.hbp_break[idx] = bp;
 159                         err = 0;
 160                 }
 161                 break;
 162         case NT_ARM_HW_WATCH:
 163                 if (idx < ARM_MAX_WRP) {
 164                         tsk->thread.debug.hbp_watch[idx] = bp;
 165                         err = 0;
 166                 }
 167                 break;
 168         }
 169
 170         return err;
 171 }
 172
 173 static struct perf_event *ptrace_hbp_create(unsigned int note_type,
 174                                             struct task_struct *tsk,
 175                                             unsigned long idx)
 176 {
 177         struct perf_event *bp;
 178         struct perf_event_attr attr;
 179         int err, type;
 180
 181         switch (note_type) {
 182         case NT_ARM_HW_BREAK:
 183                 type = HW_BREAKPOINT_X;
 184                 break;
 185         case NT_ARM_HW_WATCH:
 186                 type = HW_BREAKPOINT_RW;
 187                 break;
 188         default:
 189                 return ERR_PTR(-EINVAL);
 190         }
 191
 192         ptrace_breakpoint_init(&attr);
 193
 194         /*
 195          * Initialise fields to sane defaults
 196          * (i.e. values that will pass validation).
 197          */
 198         attr.bp_addr    = 0;
 199         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 200         attr.bp_type    = type;
 201         attr.disabled   = 1;
 202
 203         bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk);
 204         if (IS_ERR(bp))
 205                 return bp;
 206
 207         err = ptrace_hbp_set_event(note_type, tsk, idx, bp);
 208         if (err)
 209                 return ERR_PTR(err);
 210
 211         return bp;
 212 }
 213
 214 static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
 215                                      struct arch_hw_breakpoint_ctrl ctrl,
 216                                      struct perf_event_attr *attr)
 217 {
 218         int err, len, type, disabled = !ctrl.enabled;
 219
 220         if (disabled) {
 221                 len = 0;
 222                 type = HW_BREAKPOINT_EMPTY;
 223         } else {
 224                 err = arch_bp_generic_fields(ctrl, &len, &type);
 225                 if (err)
 226                         return err;
 227
 228                 switch (note_type) {
 229                 case NT_ARM_HW_BREAK:
 230                         if ((type & HW_BREAKPOINT_X) != type)
 231                                 return -EINVAL;
 232                         break;
 233                 case NT_ARM_HW_WATCH:
 234                         if ((type & HW_BREAKPOINT_RW) != type)
 235                                 return -EINVAL;
 236                         break;
 237                 default:
 238                         return -EINVAL;
 239                 }
 240         }
 241
 242         attr->bp_len    = len;
 243         attr->bp_type   = type;
 244         attr->disabled  = disabled;
 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         fpsimd_flush_task_state(target);
 526         return ret;
 527 }
 528
 529 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 530                    unsigned int pos, unsigned int count,
 531                    void *kbuf, void __user *ubuf)
 532 {
 533         unsigned long *tls = &target->thread.tp_value;
 534         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
 535 }
 536
 537 static int tls_set(struct task_struct *target, const struct user_regset *regset,
 538                    unsigned int pos, unsigned int count,
 539                    const void *kbuf, const void __user *ubuf)
 540 {
 541         int ret;
 542         unsigned long tls;
 543
 544         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 545         if (ret)
 546                 return ret;
 547
 548         target->thread.tp_value = tls;
 549         return ret;
 550 }
 551
 552 enum aarch64_regset {
 553         REGSET_GPR,
 554         REGSET_FPR,
 555         REGSET_TLS,
 556 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 557         REGSET_HW_BREAK,
 558         REGSET_HW_WATCH,
 559 #endif
 560 };
 561
 562 static const struct user_regset aarch64_regsets[] = {
 563         [REGSET_GPR] = {
 564                 .core_note_type = NT_PRSTATUS,
 565                 .n = sizeof(struct user_pt_regs) / sizeof(u64),
 566                 .size = sizeof(u64),
 567                 .align = sizeof(u64),
 568                 .get = gpr_get,
 569                 .set = gpr_set
 570         },
 571         [REGSET_FPR] = {
 572                 .core_note_type = NT_PRFPREG,
 573                 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
 574                 /*
 575                  * We pretend we have 32-bit registers because the fpsr and
 576                  * fpcr are 32-bits wide.
 577                  */
 578                 .size = sizeof(u32),
 579                 .align = sizeof(u32),
 580                 .get = fpr_get,
 581                 .set = fpr_set
 582         },
 583         [REGSET_TLS] = {
 584                 .core_note_type = NT_ARM_TLS,
 585                 .n = 1,
 586                 .size = sizeof(void *),
 587                 .align = sizeof(void *),
 588                 .get = tls_get,
 589                 .set = tls_set,
 590         },
 591 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 592         [REGSET_HW_BREAK] = {
 593                 .core_note_type = NT_ARM_HW_BREAK,
 594                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 595                 .size = sizeof(u32),
 596                 .align = sizeof(u32),
 597                 .get = hw_break_get,
 598                 .set = hw_break_set,
 599         },
 600         [REGSET_HW_WATCH] = {
 601                 .core_note_type = NT_ARM_HW_WATCH,
 602                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 603                 .size = sizeof(u32),
 604                 .align = sizeof(u32),
 605                 .get = hw_break_get,
 606                 .set = hw_break_set,
 607         },
 608 #endif
 609 };
 610
 611 static const struct user_regset_view user_aarch64_view = {
 612         .name = "aarch64", .e_machine = EM_AARCH64,
 613         .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
 614 };
 615
 616 #ifdef CONFIG_COMPAT
 617 #include <linux/compat.h>
 618
 619 enum compat_regset {
 620         REGSET_COMPAT_GPR,
 621         REGSET_COMPAT_VFP,
 622 };
 623
 624 static int compat_gpr_get(struct task_struct *target,
 625                           const struct user_regset *regset,
 626                           unsigned int pos, unsigned int count,
 627                           void *kbuf, void __user *ubuf)
 628 {
 629         int ret = 0;
 630         unsigned int i, start, num_regs;
 631
 632         /* Calculate the number of AArch32 registers contained in count */
 633         num_regs = count / regset->size;
 634
 635         /* Convert pos into an register number */
 636         start = pos / regset->size;
 637
 638         if (start + num_regs > regset->n)
 639                 return -EIO;
 640
 641         for (i = 0; i < num_regs; ++i) {
 642                 unsigned int idx = start + i;
 643                 void *reg;
 644
 645                 switch (idx) {
 646                 case 15:
 647                         reg = (void *)&task_pt_regs(target)->pc;
 648                         break;
 649                 case 16:
 650                         reg = (void *)&task_pt_regs(target)->pstate;
 651                         break;
 652                 case 17:
 653                         reg = (void *)&task_pt_regs(target)->orig_x0;
 654                         break;
 655                 default:
 656                         reg = (void *)&task_pt_regs(target)->regs[idx];
 657                 }
 658
 659                 ret = copy_to_user(ubuf, reg, sizeof(compat_ulong_t));
 660
 661                 if (ret)
 662                         break;
 663                 else
 664                         ubuf += sizeof(compat_ulong_t);
 665         }
 666
 667         return ret;
 668 }
 669
 670 static int compat_gpr_set(struct task_struct *target,
 671                           const struct user_regset *regset,
 672                           unsigned int pos, unsigned int count,
 673                           const void *kbuf, const void __user *ubuf)
 674 {
 675         struct pt_regs newregs;
 676         int ret = 0;
 677         unsigned int i, start, num_regs;
 678
 679         /* Calculate the number of AArch32 registers contained in count */
 680         num_regs = count / regset->size;
 681
 682         /* Convert pos into an register number */
 683         start = pos / regset->size;
 684
 685         if (start + num_regs > regset->n)
 686                 return -EIO;
 687
 688         newregs = *task_pt_regs(target);
 689
 690         for (i = 0; i < num_regs; ++i) {
 691                 unsigned int idx = start + i;
 692                 void *reg;
 693
 694                 switch (idx) {
 695                 case 15:
 696                         reg = (void *)&newregs.pc;
 697                         break;
 698                 case 16:
 699                         reg = (void *)&newregs.pstate;
 700                         break;
 701                 case 17:
 702                         reg = (void *)&newregs.orig_x0;
 703                         break;
 704                 default:
 705                         reg = (void *)&newregs.regs[idx];
 706                 }
 707
 708                 ret = copy_from_user(reg, ubuf, sizeof(compat_ulong_t));
 709
 710                 if (ret)
 711                         goto out;
 712                 else
 713                         ubuf += sizeof(compat_ulong_t);
 714         }
 715
 716         if (valid_user_regs(&newregs.user_regs))
 717                 *task_pt_regs(target) = newregs;
 718         else
 719                 ret = -EINVAL;
 720
 721 out:
 722         return ret;
 723 }
 724
 725 static int compat_vfp_get(struct task_struct *target,
 726                           const struct user_regset *regset,
 727                           unsigned int pos, unsigned int count,
 728                           void *kbuf, void __user *ubuf)
 729 {
 730         struct user_fpsimd_state *uregs;
 731         compat_ulong_t fpscr;
 732         int ret;
 733
 734         uregs = &target->thread.fpsimd_state.user_fpsimd;
 735
 736         /*
 737          * The VFP registers are packed into the fpsimd_state, so they all sit
 738          * nicely together for us. We just need to create the fpscr separately.
 739          */
 740         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
 741                                   VFP_STATE_SIZE - sizeof(compat_ulong_t));
 742
 743         if (count && !ret) {
 744                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
 745                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
 746                 ret = put_user(fpscr, (compat_ulong_t *)ubuf);
 747         }
 748
 749         return ret;
 750 }
 751
 752 static int compat_vfp_set(struct task_struct *target,
 753                           const struct user_regset *regset,
 754                           unsigned int pos, unsigned int count,
 755                           const void *kbuf, const void __user *ubuf)
 756 {
 757         struct user_fpsimd_state *uregs;
 758         compat_ulong_t fpscr;
 759         int ret;
 760
 761         if (pos + count > VFP_STATE_SIZE)
 762                 return -EIO;
 763
 764         uregs = &target->thread.fpsimd_state.user_fpsimd;
 765
 766         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
 767                                  VFP_STATE_SIZE - sizeof(compat_ulong_t));
 768
 769         if (count && !ret) {
 770                 ret = get_user(fpscr, (compat_ulong_t *)ubuf);
 771                 uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
 772                 uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
 773         }
 774
 775         fpsimd_flush_task_state(target);
 776         return ret;
 777 }
 778
 779 static const struct user_regset aarch32_regsets[] = {
 780         [REGSET_COMPAT_GPR] = {
 781                 .core_note_type = NT_PRSTATUS,
 782                 .n = COMPAT_ELF_NGREG,
 783                 .size = sizeof(compat_elf_greg_t),
 784                 .align = sizeof(compat_elf_greg_t),
 785                 .get = compat_gpr_get,
 786                 .set = compat_gpr_set
 787         },
 788         [REGSET_COMPAT_VFP] = {
 789                 .core_note_type = NT_ARM_VFP,
 790                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
 791                 .size = sizeof(compat_ulong_t),
 792                 .align = sizeof(compat_ulong_t),
 793                 .get = compat_vfp_get,
 794                 .set = compat_vfp_set
 795         },
 796 };
 797
 798 static const struct user_regset_view user_aarch32_view = {
 799         .name = "aarch32", .e_machine = EM_ARM,
 800         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
 801 };
 802
 803 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
 804                                    compat_ulong_t __user *ret)
 805 {
 806         compat_ulong_t tmp;
 807
 808         if (off & 3)
 809                 return -EIO;
 810
 811         if (off == COMPAT_PT_TEXT_ADDR)
 812                 tmp = tsk->mm->start_code;
 813         else if (off == COMPAT_PT_DATA_ADDR)
 814                 tmp = tsk->mm->start_data;
 815         else if (off == COMPAT_PT_TEXT_END_ADDR)
 816                 tmp = tsk->mm->end_code;
 817         else if (off < sizeof(compat_elf_gregset_t))
 818                 return copy_regset_to_user(tsk, &user_aarch32_view,
 819                                            REGSET_COMPAT_GPR, off,
 820                                            sizeof(compat_ulong_t), ret);
 821         else if (off >= COMPAT_USER_SZ)
 822                 return -EIO;
 823         else
 824                 tmp = 0;
 825
 826         return put_user(tmp, ret);
 827 }
 828
 829 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
 830                                     compat_ulong_t val)
 831 {
 832         int ret;
 833
 834         if (off & 3 || off >= COMPAT_USER_SZ)
 835                 return -EIO;
 836
 837         if (off >= sizeof(compat_elf_gregset_t))
 838                 return 0;
 839
 840         ret = copy_regset_from_user(tsk, &user_aarch32_view,
 841                                     REGSET_COMPAT_GPR, off,
 842                                     sizeof(compat_ulong_t),
 843                                     &val);
 844         return ret;
 845 }
 846
 847 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 848
 849 /*
 850  * Convert a virtual register number into an index for a thread_info
 851  * breakpoint array. Breakpoints are identified using positive numbers
 852  * whilst watchpoints are negative. The registers are laid out as pairs
 853  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
 854  * Register 0 is reserved for describing resource information.
 855  */
 856 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
 857 {
 858         return (abs(num) - 1) >> 1;
 859 }
 860
 861 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
 862 {
 863         u8 num_brps, num_wrps, debug_arch, wp_len;
 864         u32 reg = 0;
 865
 866         num_brps        = hw_breakpoint_slots(TYPE_INST);
 867         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
 868
 869         debug_arch      = debug_monitors_arch();
 870         wp_len          = 8;
 871         reg             |= debug_arch;
 872         reg             <<= 8;
 873         reg             |= wp_len;
 874         reg             <<= 8;
 875         reg             |= num_wrps;
 876         reg             <<= 8;
 877         reg             |= num_brps;
 878
 879         *kdata = reg;
 880         return 0;
 881 }
 882
 883 static int compat_ptrace_hbp_get(unsigned int note_type,
 884                                  struct task_struct *tsk,
 885                                  compat_long_t num,
 886                                  u32 *kdata)
 887 {
 888         u64 addr = 0;
 889         u32 ctrl = 0;
 890
 891         int err, idx = compat_ptrace_hbp_num_to_idx(num);;
 892
 893         if (num & 1) {
 894                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
 895                 *kdata = (u32)addr;
 896         } else {
 897                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
 898                 *kdata = ctrl;
 899         }
 900
 901         return err;
 902 }
 903
 904 static int compat_ptrace_hbp_set(unsigned int note_type,
 905                                  struct task_struct *tsk,
 906                                  compat_long_t num,
 907                                  u32 *kdata)
 908 {
 909         u64 addr;
 910         u32 ctrl;
 911
 912         int err, idx = compat_ptrace_hbp_num_to_idx(num);
 913
 914         if (num & 1) {
 915                 addr = *kdata;
 916                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
 917         } else {
 918                 ctrl = *kdata;
 919                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
 920         }
 921
 922         return err;
 923 }
 924
 925 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
 926                                     compat_ulong_t __user *data)
 927 {
 928         int ret;
 929         u32 kdata;
 930         mm_segment_t old_fs = get_fs();
 931
 932         set_fs(KERNEL_DS);
 933         /* Watchpoint */
 934         if (num < 0) {
 935                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
 936         /* Resource info */
 937         } else if (num == 0) {
 938                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
 939         /* Breakpoint */
 940         } else {
 941                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
 942         }
 943         set_fs(old_fs);
 944
 945         if (!ret)
 946                 ret = put_user(kdata, data);
 947
 948         return ret;
 949 }
 950
 951 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
 952                                     compat_ulong_t __user *data)
 953 {
 954         int ret;
 955         u32 kdata = 0;
 956         mm_segment_t old_fs = get_fs();
 957
 958         if (num == 0)
 959                 return 0;
 960
 961         ret = get_user(kdata, data);
 962         if (ret)
 963                 return ret;
 964
 965         set_fs(KERNEL_DS);
 966         if (num < 0)
 967                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
 968         else
 969                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
 970         set_fs(old_fs);
 971
 972         return ret;
 973 }
 974 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 975
 976 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 977                         compat_ulong_t caddr, compat_ulong_t cdata)
 978 {
 979         unsigned long addr = caddr;
 980         unsigned long data = cdata;
 981         void __user *datap = compat_ptr(data);
 982         int ret;
 983
 984         switch (request) {
 985                 case PTRACE_PEEKUSR:
 986                         ret = compat_ptrace_read_user(child, addr, datap);
 987                         break;
 988
 989                 case PTRACE_POKEUSR:
 990                         ret = compat_ptrace_write_user(child, addr, data);
 991                         break;
 992
 993                 case COMPAT_PTRACE_GETREGS:
 994                         ret = copy_regset_to_user(child,
 995                                                   &user_aarch32_view,
 996                                                   REGSET_COMPAT_GPR,
 997                                                   0, sizeof(compat_elf_gregset_t),
 998                                                   datap);
 999                         break;
1000
1001                 case COMPAT_PTRACE_SETREGS:
1002                         ret = copy_regset_from_user(child,
1003                                                     &user_aarch32_view,
1004                                                     REGSET_COMPAT_GPR,
1005                                                     0, sizeof(compat_elf_gregset_t),
1006                                                     datap);
1007                         break;
1008
1009                 case COMPAT_PTRACE_GET_THREAD_AREA:
1010                         ret = put_user((compat_ulong_t)child->thread.tp_value,
1011                                        (compat_ulong_t __user *)datap);
1012                         break;
1013
1014                 case COMPAT_PTRACE_SET_SYSCALL:
1015                         task_pt_regs(child)->syscallno = data;
1016                         ret = 0;
1017                         break;
1018
1019                 case COMPAT_PTRACE_GETVFPREGS:
1020                         ret = copy_regset_to_user(child,
1021                                                   &user_aarch32_view,
1022                                                   REGSET_COMPAT_VFP,
1023                                                   0, VFP_STATE_SIZE,
1024                                                   datap);
1025                         break;
1026
1027                 case COMPAT_PTRACE_SETVFPREGS:
1028                         ret = copy_regset_from_user(child,
1029                                                     &user_aarch32_view,
1030                                                     REGSET_COMPAT_VFP,
1031                                                     0, VFP_STATE_SIZE,
1032                                                     datap);
1033                         break;
1034
1035 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1036                 case COMPAT_PTRACE_GETHBPREGS:
1037                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1038                         break;
1039
1040                 case COMPAT_PTRACE_SETHBPREGS:
1041                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1042                         break;
1043 #endif
1044
1045                 default:
1046                         ret = compat_ptrace_request(child, request, addr,
1047                                                     data);
1048                         break;
1049         }
1050
1051         return ret;
1052 }
1053 #endif /* CONFIG_COMPAT */
1054
1055 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1056 {
1057 #ifdef CONFIG_COMPAT
1058         if (is_compat_thread(task_thread_info(task)))
1059                 return &user_aarch32_view;
1060 #endif
1061         return &user_aarch64_view;
1062 }
1063
1064 long arch_ptrace(struct task_struct *child, long request,
1065                  unsigned long addr, unsigned long data)
1066 {
1067         return ptrace_request(child, request, addr, data);
1068 }
1069
1070 enum ptrace_syscall_dir {
1071         PTRACE_SYSCALL_ENTER = 0,
1072         PTRACE_SYSCALL_EXIT,
1073 };
1074
1075 static void tracehook_report_syscall(struct pt_regs *regs,
1076                                      enum ptrace_syscall_dir dir)
1077 {
1078         int regno;
1079         unsigned long saved_reg;
1080
1081         /*
1082          * A scratch register (ip(r12) on AArch32, x7 on AArch64) is
1083          * used to denote syscall entry/exit:
1084          */
1085         regno = (is_compat_task() ? 12 : 7);
1086         saved_reg = regs->regs[regno];
1087         regs->regs[regno] = dir;
1088
1089         if (dir == PTRACE_SYSCALL_EXIT)
1090                 tracehook_report_syscall_exit(regs, 0);
1091         else if (tracehook_report_syscall_entry(regs))
1092                 regs->syscallno = ~0UL;
1093
1094         regs->regs[regno] = saved_reg;
1095 }
1096
1097 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
1098 {
1099         if (test_thread_flag(TIF_SYSCALL_TRACE))
1100                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1101
1102         audit_syscall_entry(syscall_get_arch(), regs->syscallno,
1103                 regs->orig_x0, regs->regs[1], regs->regs[2], regs->regs[3]);
1104
1105         return regs->syscallno;
1106 }
1107
1108 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
1109 {
1110         audit_syscall_exit(regs);
1111
1112         if (test_thread_flag(TIF_SYSCALL_TRACE))
1113                 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1114 }