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 #define CREATE_TRACE_POINTS
  48 #include <trace/events/syscalls.h>
  49
  50 /*
  51  * TODO: does not yet catch signals sent when the child dies.
  52  * in exit.c or in signal.c.
  53  */
  54
  55 /*
  56  * Called by kernel/ptrace.c when detaching..
  57  */
  58 void ptrace_disable(struct task_struct *child)
  59 {
  60 }
  61
  62 #ifdef CONFIG_HAVE_HW_BREAKPOINT
  63 /*
  64  * Handle hitting a HW-breakpoint.
  65  */
  66 static void ptrace_hbptriggered(struct perf_event *bp,
  67                                 struct perf_sample_data *data,
  68                                 struct pt_regs *regs)
  69 {
  70         struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
  71         siginfo_t info = {
  72                 .si_signo       = SIGTRAP,
  73                 .si_errno       = 0,
  74                 .si_code        = TRAP_HWBKPT,
  75                 .si_addr        = (void __user *)(bkpt->trigger),
  76         };
  77
  78 #ifdef CONFIG_COMPAT
  79         int i;
  80
  81         if (!is_compat_task())
  82                 goto send_sig;
  83
  84         for (i = 0; i < ARM_MAX_BRP; ++i) {
  85                 if (current->thread.debug.hbp_break[i] == bp) {
  86                         info.si_errno = (i << 1) + 1;
  87                         break;
  88                 }
  89         }
  90
  91         for (i = 0; i < ARM_MAX_WRP; ++i) {
  92                 if (current->thread.debug.hbp_watch[i] == bp) {
  93                         info.si_errno = -((i << 1) + 1);
  94                         break;
  95                 }
  96         }
  97
  98 send_sig:
  99 #endif
 100         force_sig_info(SIGTRAP, &info, current);
 101 }
 102
 103 /*
 104  * Unregister breakpoints from this task and reset the pointers in
 105  * the thread_struct.
 106  */
 107 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 108 {
 109         int i;
 110         struct thread_struct *t = &tsk->thread;
 111
 112         for (i = 0; i < ARM_MAX_BRP; i++) {
 113                 if (t->debug.hbp_break[i]) {
 114                         unregister_hw_breakpoint(t->debug.hbp_break[i]);
 115                         t->debug.hbp_break[i] = NULL;
 116                 }
 117         }
 118
 119         for (i = 0; i < ARM_MAX_WRP; i++) {
 120                 if (t->debug.hbp_watch[i]) {
 121                         unregister_hw_breakpoint(t->debug.hbp_watch[i]);
 122                         t->debug.hbp_watch[i] = NULL;
 123                 }
 124         }
 125 }
 126
 127 void ptrace_hw_copy_thread(struct task_struct *tsk)
 128 {
 129         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 130 }
 131
 132 static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
 133                                                struct task_struct *tsk,
 134                                                unsigned long idx)
 135 {
 136         struct perf_event *bp = ERR_PTR(-EINVAL);
 137
 138         switch (note_type) {
 139         case NT_ARM_HW_BREAK:
 140                 if (idx < ARM_MAX_BRP)
 141                         bp = tsk->thread.debug.hbp_break[idx];
 142                 break;
 143         case NT_ARM_HW_WATCH:
 144                 if (idx < ARM_MAX_WRP)
 145                         bp = tsk->thread.debug.hbp_watch[idx];
 146                 break;
 147         }
 148
 149         return bp;
 150 }
 151
 152 static int ptrace_hbp_set_event(unsigned int note_type,
 153                                 struct task_struct *tsk,
 154                                 unsigned long idx,
 155                                 struct perf_event *bp)
 156 {
 157         int err = -EINVAL;
 158
 159         switch (note_type) {
 160         case NT_ARM_HW_BREAK:
 161                 if (idx < ARM_MAX_BRP) {
 162                         tsk->thread.debug.hbp_break[idx] = bp;
 163                         err = 0;
 164                 }
 165                 break;
 166         case NT_ARM_HW_WATCH:
 167                 if (idx < ARM_MAX_WRP) {
 168                         tsk->thread.debug.hbp_watch[idx] = bp;
 169                         err = 0;
 170                 }
 171                 break;
 172         }
 173
 174         return err;
 175 }
 176
 177 static struct perf_event *ptrace_hbp_create(unsigned int note_type,
 178                                             struct task_struct *tsk,
 179                                             unsigned long idx)
 180 {
 181         struct perf_event *bp;
 182         struct perf_event_attr attr;
 183         int err, type;
 184
 185         switch (note_type) {
 186         case NT_ARM_HW_BREAK:
 187                 type = HW_BREAKPOINT_X;
 188                 break;
 189         case NT_ARM_HW_WATCH:
 190                 type = HW_BREAKPOINT_RW;
 191                 break;
 192         default:
 193                 return ERR_PTR(-EINVAL);
 194         }
 195
 196         ptrace_breakpoint_init(&attr);
 197
 198         /*
 199          * Initialise fields to sane defaults
 200          * (i.e. values that will pass validation).
 201          */
 202         attr.bp_addr    = 0;
 203         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 204         attr.bp_type    = type;
 205         attr.disabled   = 1;
 206
 207         bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk);
 208         if (IS_ERR(bp))
 209                 return bp;
 210
 211         err = ptrace_hbp_set_event(note_type, tsk, idx, bp);
 212         if (err)
 213                 return ERR_PTR(err);
 214
 215         return bp;
 216 }
 217
 218 static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
 219                                      struct arch_hw_breakpoint_ctrl ctrl,
 220                                      struct perf_event_attr *attr)
 221 {
 222         int err, len, type, disabled = !ctrl.enabled;
 223
 224         attr->disabled = disabled;
 225         if (disabled)
 226                 return 0;
 227
 228         err = arch_bp_generic_fields(ctrl, &len, &type);
 229         if (err)
 230                 return err;
 231
 232         switch (note_type) {
 233         case NT_ARM_HW_BREAK:
 234                 if ((type & HW_BREAKPOINT_X) != type)
 235                         return -EINVAL;
 236                 break;
 237         case NT_ARM_HW_WATCH:
 238                 if ((type & HW_BREAKPOINT_RW) != type)
 239                         return -EINVAL;
 240                 break;
 241         default:
 242                 return -EINVAL;
 243         }
 244
 245         attr->bp_len    = len;
 246         attr->bp_type   = type;
 247
 248         return 0;
 249 }
 250
 251 static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info)
 252 {
 253         u8 num;
 254         u32 reg = 0;
 255
 256         switch (note_type) {
 257         case NT_ARM_HW_BREAK:
 258                 num = hw_breakpoint_slots(TYPE_INST);
 259                 break;
 260         case NT_ARM_HW_WATCH:
 261                 num = hw_breakpoint_slots(TYPE_DATA);
 262                 break;
 263         default:
 264                 return -EINVAL;
 265         }
 266
 267         reg |= debug_monitors_arch();
 268         reg <<= 8;
 269         reg |= num;
 270
 271         *info = reg;
 272         return 0;
 273 }
 274
 275 static int ptrace_hbp_get_ctrl(unsigned int note_type,
 276                                struct task_struct *tsk,
 277                                unsigned long idx,
 278                                u32 *ctrl)
 279 {
 280         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 281
 282         if (IS_ERR(bp))
 283                 return PTR_ERR(bp);
 284
 285         *ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0;
 286         return 0;
 287 }
 288
 289 static int ptrace_hbp_get_addr(unsigned int note_type,
 290                                struct task_struct *tsk,
 291                                unsigned long idx,
 292                                u64 *addr)
 293 {
 294         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 295
 296         if (IS_ERR(bp))
 297                 return PTR_ERR(bp);
 298
 299         *addr = bp ? bp->attr.bp_addr : 0;
 300         return 0;
 301 }
 302
 303 static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type,
 304                                                         struct task_struct *tsk,
 305                                                         unsigned long idx)
 306 {
 307         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 308
 309         if (!bp)
 310                 bp = ptrace_hbp_create(note_type, tsk, idx);
 311
 312         return bp;
 313 }
 314
 315 static int ptrace_hbp_set_ctrl(unsigned int note_type,
 316                                struct task_struct *tsk,
 317                                unsigned long idx,
 318                                u32 uctrl)
 319 {
 320         int err;
 321         struct perf_event *bp;
 322         struct perf_event_attr attr;
 323         struct arch_hw_breakpoint_ctrl ctrl;
 324
 325         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 326         if (IS_ERR(bp)) {
 327                 err = PTR_ERR(bp);
 328                 return err;
 329         }
 330
 331         attr = bp->attr;
 332         decode_ctrl_reg(uctrl, &ctrl);
 333         err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
 334         if (err)
 335                 return err;
 336
 337         return modify_user_hw_breakpoint(bp, &attr);
 338 }
 339
 340 static int ptrace_hbp_set_addr(unsigned int note_type,
 341                                struct task_struct *tsk,
 342                                unsigned long idx,
 343                                u64 addr)
 344 {
 345         int err;
 346         struct perf_event *bp;
 347         struct perf_event_attr attr;
 348
 349         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 350         if (IS_ERR(bp)) {
 351                 err = PTR_ERR(bp);
 352                 return err;
 353         }
 354
 355         attr = bp->attr;
 356         attr.bp_addr = addr;
 357         err = modify_user_hw_breakpoint(bp, &attr);
 358         return err;
 359 }
 360
 361 #define PTRACE_HBP_ADDR_SZ      sizeof(u64)
 362 #define PTRACE_HBP_CTRL_SZ      sizeof(u32)
 363 #define PTRACE_HBP_PAD_SZ       sizeof(u32)
 364
 365 static int hw_break_get(struct task_struct *target,
 366                         const struct user_regset *regset,
 367                         unsigned int pos, unsigned int count,
 368                         void *kbuf, void __user *ubuf)
 369 {
 370         unsigned int note_type = regset->core_note_type;
 371         int ret, idx = 0, offset, limit;
 372         u32 info, ctrl;
 373         u64 addr;
 374
 375         /* Resource info */
 376         ret = ptrace_hbp_get_resource_info(note_type, &info);
 377         if (ret)
 378                 return ret;
 379
 380         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0,
 381                                   sizeof(info));
 382         if (ret)
 383                 return ret;
 384
 385         /* Pad */
 386         offset = offsetof(struct user_hwdebug_state, pad);
 387         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, offset,
 388                                        offset + PTRACE_HBP_PAD_SZ);
 389         if (ret)
 390                 return ret;
 391
 392         /* (address, ctrl) registers */
 393         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 394         limit = regset->n * regset->size;
 395         while (count && offset < limit) {
 396                 ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
 397                 if (ret)
 398                         return ret;
 399                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr,
 400                                           offset, offset + PTRACE_HBP_ADDR_SZ);
 401                 if (ret)
 402                         return ret;
 403                 offset += PTRACE_HBP_ADDR_SZ;
 404
 405                 ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
 406                 if (ret)
 407                         return ret;
 408                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl,
 409                                           offset, offset + PTRACE_HBP_CTRL_SZ);
 410                 if (ret)
 411                         return ret;
 412                 offset += PTRACE_HBP_CTRL_SZ;
 413
 414                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 415                                                offset,
 416                                                offset + PTRACE_HBP_PAD_SZ);
 417                 if (ret)
 418                         return ret;
 419                 offset += PTRACE_HBP_PAD_SZ;
 420                 idx++;
 421         }
 422
 423         return 0;
 424 }
 425
 426 static int hw_break_set(struct task_struct *target,
 427                         const struct user_regset *regset,
 428                         unsigned int pos, unsigned int count,
 429                         const void *kbuf, const void __user *ubuf)
 430 {
 431         unsigned int note_type = regset->core_note_type;
 432         int ret, idx = 0, offset, limit;
 433         u32 ctrl;
 434         u64 addr;
 435
 436         /* Resource info and pad */
 437         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 438         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset);
 439         if (ret)
 440                 return ret;
 441
 442         /* (address, ctrl) registers */
 443         limit = regset->n * regset->size;
 444         while (count && offset < limit) {
 445                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
 446                                          offset, offset + PTRACE_HBP_ADDR_SZ);
 447                 if (ret)
 448                         return ret;
 449                 ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
 450                 if (ret)
 451                         return ret;
 452                 offset += PTRACE_HBP_ADDR_SZ;
 453
 454                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
 455                                          offset, offset + PTRACE_HBP_CTRL_SZ);
 456                 if (ret)
 457                         return ret;
 458                 ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
 459                 if (ret)
 460                         return ret;
 461                 offset += PTRACE_HBP_CTRL_SZ;
 462
 463                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 464                                                 offset,
 465                                                 offset + PTRACE_HBP_PAD_SZ);
 466                 if (ret)
 467                         return ret;
 468                 offset += PTRACE_HBP_PAD_SZ;
 469                 idx++;
 470         }
 471
 472         return 0;
 473 }
 474 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 475
 476 static int gpr_get(struct task_struct *target,
 477                    const struct user_regset *regset,
 478                    unsigned int pos, unsigned int count,
 479                    void *kbuf, void __user *ubuf)
 480 {
 481         struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
 482         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 483 }
 484
 485 static int gpr_set(struct task_struct *target, const struct user_regset *regset,
 486                    unsigned int pos, unsigned int count,
 487                    const void *kbuf, const void __user *ubuf)
 488 {
 489         int ret;
 490         struct user_pt_regs newregs;
 491
 492         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
 493         if (ret)
 494                 return ret;
 495
 496         if (!valid_user_regs(&newregs))
 497                 return -EINVAL;
 498
 499         task_pt_regs(target)->user_regs = newregs;
 500         return 0;
 501 }
 502
 503 /*
 504  * TODO: update fp accessors for lazy context switching (sync/flush hwstate)
 505  */
 506 static int fpr_get(struct task_struct *target, const struct user_regset *regset,
 507                    unsigned int pos, unsigned int count,
 508                    void *kbuf, void __user *ubuf)
 509 {
 510         struct user_fpsimd_state *uregs;
 511         uregs = &target->thread.fpsimd_state.user_fpsimd;
 512         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 513 }
 514
 515 static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 516                    unsigned int pos, unsigned int count,
 517                    const void *kbuf, const void __user *ubuf)
 518 {
 519         int ret;
 520         struct user_fpsimd_state newstate;
 521
 522         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1);
 523         if (ret)
 524                 return ret;
 525
 526         target->thread.fpsimd_state.user_fpsimd = newstate;
 527         fpsimd_flush_task_state(target);
 528         return ret;
 529 }
 530
 531 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 532                    unsigned int pos, unsigned int count,
 533                    void *kbuf, void __user *ubuf)
 534 {
 535         unsigned long *tls = &target->thread.tp_value;
 536         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
 537 }
 538
 539 static int tls_set(struct task_struct *target, const struct user_regset *regset,
 540                    unsigned int pos, unsigned int count,
 541                    const void *kbuf, const void __user *ubuf)
 542 {
 543         int ret;
 544         unsigned long tls;
 545
 546         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 547         if (ret)
 548                 return ret;
 549
 550         target->thread.tp_value = tls;
 551         return ret;
 552 }
 553
 554 enum aarch64_regset {
 555         REGSET_GPR,
 556         REGSET_FPR,
 557         REGSET_TLS,
 558 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 559         REGSET_HW_BREAK,
 560         REGSET_HW_WATCH,
 561 #endif
 562 };
 563
 564 static const struct user_regset aarch64_regsets[] = {
 565         [REGSET_GPR] = {
 566                 .core_note_type = NT_PRSTATUS,
 567                 .n = sizeof(struct user_pt_regs) / sizeof(u64),
 568                 .size = sizeof(u64),
 569                 .align = sizeof(u64),
 570                 .get = gpr_get,
 571                 .set = gpr_set
 572         },
 573         [REGSET_FPR] = {
 574                 .core_note_type = NT_PRFPREG,
 575                 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
 576                 /*
 577                  * We pretend we have 32-bit registers because the fpsr and
 578                  * fpcr are 32-bits wide.
 579                  */
 580                 .size = sizeof(u32),
 581                 .align = sizeof(u32),
 582                 .get = fpr_get,
 583                 .set = fpr_set
 584         },
 585         [REGSET_TLS] = {
 586                 .core_note_type = NT_ARM_TLS,
 587                 .n = 1,
 588                 .size = sizeof(void *),
 589                 .align = sizeof(void *),
 590                 .get = tls_get,
 591                 .set = tls_set,
 592         },
 593 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 594         [REGSET_HW_BREAK] = {
 595                 .core_note_type = NT_ARM_HW_BREAK,
 596                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 597                 .size = sizeof(u32),
 598                 .align = sizeof(u32),
 599                 .get = hw_break_get,
 600                 .set = hw_break_set,
 601         },
 602         [REGSET_HW_WATCH] = {
 603                 .core_note_type = NT_ARM_HW_WATCH,
 604                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 605                 .size = sizeof(u32),
 606                 .align = sizeof(u32),
 607                 .get = hw_break_get,
 608                 .set = hw_break_set,
 609         },
 610 #endif
 611 };
 612
 613 static const struct user_regset_view user_aarch64_view = {
 614         .name = "aarch64", .e_machine = EM_AARCH64,
 615         .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
 616 };
 617
 618 #ifdef CONFIG_COMPAT
 619 #include <linux/compat.h>
 620
 621 enum compat_regset {
 622         REGSET_COMPAT_GPR,
 623         REGSET_COMPAT_VFP,
 624 };
 625
 626 static int compat_gpr_get(struct task_struct *target,
 627                           const struct user_regset *regset,
 628                           unsigned int pos, unsigned int count,
 629                           void *kbuf, void __user *ubuf)
 630 {
 631         int ret = 0;
 632         unsigned int i, start, num_regs;
 633
 634         /* Calculate the number of AArch32 registers contained in count */
 635         num_regs = count / regset->size;
 636
 637         /* Convert pos into an register number */
 638         start = pos / regset->size;
 639
 640         if (start + num_regs > regset->n)
 641                 return -EIO;
 642
 643         for (i = 0; i < num_regs; ++i) {
 644                 unsigned int idx = start + i;
 645                 compat_ulong_t reg;
 646
 647                 switch (idx) {
 648                 case 15:
 649                         reg = task_pt_regs(target)->pc;
 650                         break;
 651                 case 16:
 652                         reg = task_pt_regs(target)->pstate;
 653                         break;
 654                 case 17:
 655                         reg = task_pt_regs(target)->orig_x0;
 656                         break;
 657                 default:
 658                         reg = task_pt_regs(target)->regs[idx];
 659                 }
 660
 661                 if (kbuf) {
 662                         memcpy(kbuf, &reg, sizeof(reg));
 663                         kbuf += sizeof(reg);
 664                 } else {
 665                         ret = copy_to_user(ubuf, &reg, sizeof(reg));
 666                         if (ret) {
 667                                 ret = -EFAULT;
 668                                 break;
 669                         }
 670
 671                         ubuf += sizeof(reg);
 672                 }
 673         }
 674
 675         return ret;
 676 }
 677
 678 static int compat_gpr_set(struct task_struct *target,
 679                           const struct user_regset *regset,
 680                           unsigned int pos, unsigned int count,
 681                           const void *kbuf, const void __user *ubuf)
 682 {
 683         struct pt_regs newregs;
 684         int ret = 0;
 685         unsigned int i, start, num_regs;
 686
 687         /* Calculate the number of AArch32 registers contained in count */
 688         num_regs = count / regset->size;
 689
 690         /* Convert pos into an register number */
 691         start = pos / regset->size;
 692
 693         if (start + num_regs > regset->n)
 694                 return -EIO;
 695
 696         newregs = *task_pt_regs(target);
 697
 698         for (i = 0; i < num_regs; ++i) {
 699                 unsigned int idx = start + i;
 700                 compat_ulong_t reg;
 701
 702                 if (kbuf) {
 703                         memcpy(&reg, kbuf, sizeof(reg));
 704                         kbuf += sizeof(reg);
 705                 } else {
 706                         ret = copy_from_user(&reg, ubuf, sizeof(reg));
 707                         if (ret) {
 708                                 ret = -EFAULT;
 709                                 break;
 710                         }
 711
 712                         ubuf += sizeof(reg);
 713                 }
 714
 715                 switch (idx) {
 716                 case 15:
 717                         newregs.pc = reg;
 718                         break;
 719                 case 16:
 720                         newregs.pstate = reg;
 721                         break;
 722                 case 17:
 723                         newregs.orig_x0 = reg;
 724                         break;
 725                 default:
 726                         newregs.regs[idx] = reg;
 727                 }
 728
 729         }
 730
 731         if (valid_user_regs(&newregs.user_regs))
 732                 *task_pt_regs(target) = newregs;
 733         else
 734                 ret = -EINVAL;
 735
 736         return ret;
 737 }
 738
 739 static int compat_vfp_get(struct task_struct *target,
 740                           const struct user_regset *regset,
 741                           unsigned int pos, unsigned int count,
 742                           void *kbuf, void __user *ubuf)
 743 {
 744         struct user_fpsimd_state *uregs;
 745         compat_ulong_t fpscr;
 746         int ret;
 747
 748         uregs = &target->thread.fpsimd_state.user_fpsimd;
 749
 750         /*
 751          * The VFP registers are packed into the fpsimd_state, so they all sit
 752          * nicely together for us. We just need to create the fpscr separately.
 753          */
 754         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
 755                                   VFP_STATE_SIZE - sizeof(compat_ulong_t));
 756
 757         if (count && !ret) {
 758                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
 759                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
 760                 ret = put_user(fpscr, (compat_ulong_t *)ubuf);
 761         }
 762
 763         return ret;
 764 }
 765
 766 static int compat_vfp_set(struct task_struct *target,
 767                           const struct user_regset *regset,
 768                           unsigned int pos, unsigned int count,
 769                           const void *kbuf, const void __user *ubuf)
 770 {
 771         struct user_fpsimd_state *uregs;
 772         compat_ulong_t fpscr;
 773         int ret;
 774
 775         if (pos + count > VFP_STATE_SIZE)
 776                 return -EIO;
 777
 778         uregs = &target->thread.fpsimd_state.user_fpsimd;
 779
 780         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
 781                                  VFP_STATE_SIZE - sizeof(compat_ulong_t));
 782
 783         if (count && !ret) {
 784                 ret = get_user(fpscr, (compat_ulong_t *)ubuf);
 785                 uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
 786                 uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
 787         }
 788
 789         fpsimd_flush_task_state(target);
 790         return ret;
 791 }
 792
 793 static const struct user_regset aarch32_regsets[] = {
 794         [REGSET_COMPAT_GPR] = {
 795                 .core_note_type = NT_PRSTATUS,
 796                 .n = COMPAT_ELF_NGREG,
 797                 .size = sizeof(compat_elf_greg_t),
 798                 .align = sizeof(compat_elf_greg_t),
 799                 .get = compat_gpr_get,
 800                 .set = compat_gpr_set
 801         },
 802         [REGSET_COMPAT_VFP] = {
 803                 .core_note_type = NT_ARM_VFP,
 804                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
 805                 .size = sizeof(compat_ulong_t),
 806                 .align = sizeof(compat_ulong_t),
 807                 .get = compat_vfp_get,
 808                 .set = compat_vfp_set
 809         },
 810 };
 811
 812 static const struct user_regset_view user_aarch32_view = {
 813         .name = "aarch32", .e_machine = EM_ARM,
 814         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
 815 };
 816
 817 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
 818                                    compat_ulong_t __user *ret)
 819 {
 820         compat_ulong_t tmp;
 821
 822         if (off & 3)
 823                 return -EIO;
 824
 825         if (off == COMPAT_PT_TEXT_ADDR)
 826                 tmp = tsk->mm->start_code;
 827         else if (off == COMPAT_PT_DATA_ADDR)
 828                 tmp = tsk->mm->start_data;
 829         else if (off == COMPAT_PT_TEXT_END_ADDR)
 830                 tmp = tsk->mm->end_code;
 831         else if (off < sizeof(compat_elf_gregset_t))
 832                 return copy_regset_to_user(tsk, &user_aarch32_view,
 833                                            REGSET_COMPAT_GPR, off,
 834                                            sizeof(compat_ulong_t), ret);
 835         else if (off >= COMPAT_USER_SZ)
 836                 return -EIO;
 837         else
 838                 tmp = 0;
 839
 840         return put_user(tmp, ret);
 841 }
 842
 843 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
 844                                     compat_ulong_t val)
 845 {
 846         int ret;
 847         mm_segment_t old_fs = get_fs();
 848
 849         if (off & 3 || off >= COMPAT_USER_SZ)
 850                 return -EIO;
 851
 852         if (off >= sizeof(compat_elf_gregset_t))
 853                 return 0;
 854
 855         set_fs(KERNEL_DS);
 856         ret = copy_regset_from_user(tsk, &user_aarch32_view,
 857                                     REGSET_COMPAT_GPR, off,
 858                                     sizeof(compat_ulong_t),
 859                                     &val);
 860         set_fs(old_fs);
 861
 862         return ret;
 863 }
 864
 865 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 866
 867 /*
 868  * Convert a virtual register number into an index for a thread_info
 869  * breakpoint array. Breakpoints are identified using positive numbers
 870  * whilst watchpoints are negative. The registers are laid out as pairs
 871  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
 872  * Register 0 is reserved for describing resource information.
 873  */
 874 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
 875 {
 876         return (abs(num) - 1) >> 1;
 877 }
 878
 879 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
 880 {
 881         u8 num_brps, num_wrps, debug_arch, wp_len;
 882         u32 reg = 0;
 883
 884         num_brps        = hw_breakpoint_slots(TYPE_INST);
 885         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
 886
 887         debug_arch      = debug_monitors_arch();
 888         wp_len          = 8;
 889         reg             |= debug_arch;
 890         reg             <<= 8;
 891         reg             |= wp_len;
 892         reg             <<= 8;
 893         reg             |= num_wrps;
 894         reg             <<= 8;
 895         reg             |= num_brps;
 896
 897         *kdata = reg;
 898         return 0;
 899 }
 900
 901 static int compat_ptrace_hbp_get(unsigned int note_type,
 902                                  struct task_struct *tsk,
 903                                  compat_long_t num,
 904                                  u32 *kdata)
 905 {
 906         u64 addr = 0;
 907         u32 ctrl = 0;
 908
 909         int err, idx = compat_ptrace_hbp_num_to_idx(num);;
 910
 911         if (num & 1) {
 912                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
 913                 *kdata = (u32)addr;
 914         } else {
 915                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
 916                 *kdata = ctrl;
 917         }
 918
 919         return err;
 920 }
 921
 922 static int compat_ptrace_hbp_set(unsigned int note_type,
 923                                  struct task_struct *tsk,
 924                                  compat_long_t num,
 925                                  u32 *kdata)
 926 {
 927         u64 addr;
 928         u32 ctrl;
 929
 930         int err, idx = compat_ptrace_hbp_num_to_idx(num);
 931
 932         if (num & 1) {
 933                 addr = *kdata;
 934                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
 935         } else {
 936                 ctrl = *kdata;
 937                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
 938         }
 939
 940         return err;
 941 }
 942
 943 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
 944                                     compat_ulong_t __user *data)
 945 {
 946         int ret;
 947         u32 kdata;
 948         mm_segment_t old_fs = get_fs();
 949
 950         set_fs(KERNEL_DS);
 951         /* Watchpoint */
 952         if (num < 0) {
 953                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
 954         /* Resource info */
 955         } else if (num == 0) {
 956                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
 957         /* Breakpoint */
 958         } else {
 959                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
 960         }
 961         set_fs(old_fs);
 962
 963         if (!ret)
 964                 ret = put_user(kdata, data);
 965
 966         return ret;
 967 }
 968
 969 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
 970                                     compat_ulong_t __user *data)
 971 {
 972         int ret;
 973         u32 kdata = 0;
 974         mm_segment_t old_fs = get_fs();
 975
 976         if (num == 0)
 977                 return 0;
 978
 979         ret = get_user(kdata, data);
 980         if (ret)
 981                 return ret;
 982
 983         set_fs(KERNEL_DS);
 984         if (num < 0)
 985                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
 986         else
 987                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
 988         set_fs(old_fs);
 989
 990         return ret;
 991 }
 992 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 993
 994 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 995                         compat_ulong_t caddr, compat_ulong_t cdata)
 996 {
 997         unsigned long addr = caddr;
 998         unsigned long data = cdata;
 999         void __user *datap = compat_ptr(data);
1000         int ret;
1001
1002         switch (request) {
1003                 case PTRACE_PEEKUSR:
1004                         ret = compat_ptrace_read_user(child, addr, datap);
1005                         break;
1006
1007                 case PTRACE_POKEUSR:
1008                         ret = compat_ptrace_write_user(child, addr, data);
1009                         break;
1010
1011                 case COMPAT_PTRACE_GETREGS:
1012                         ret = copy_regset_to_user(child,
1013                                                   &user_aarch32_view,
1014                                                   REGSET_COMPAT_GPR,
1015                                                   0, sizeof(compat_elf_gregset_t),
1016                                                   datap);
1017                         break;
1018
1019                 case COMPAT_PTRACE_SETREGS:
1020                         ret = copy_regset_from_user(child,
1021                                                     &user_aarch32_view,
1022                                                     REGSET_COMPAT_GPR,
1023                                                     0, sizeof(compat_elf_gregset_t),
1024                                                     datap);
1025                         break;
1026
1027                 case COMPAT_PTRACE_GET_THREAD_AREA:
1028                         ret = put_user((compat_ulong_t)child->thread.tp_value,
1029                                        (compat_ulong_t __user *)datap);
1030                         break;
1031
1032                 case COMPAT_PTRACE_SET_SYSCALL:
1033                         task_pt_regs(child)->syscallno = data;
1034                         ret = 0;
1035                         break;
1036
1037                 case COMPAT_PTRACE_GETVFPREGS:
1038                         ret = copy_regset_to_user(child,
1039                                                   &user_aarch32_view,
1040                                                   REGSET_COMPAT_VFP,
1041                                                   0, VFP_STATE_SIZE,
1042                                                   datap);
1043                         break;
1044
1045                 case COMPAT_PTRACE_SETVFPREGS:
1046                         ret = copy_regset_from_user(child,
1047                                                     &user_aarch32_view,
1048                                                     REGSET_COMPAT_VFP,
1049                                                     0, VFP_STATE_SIZE,
1050                                                     datap);
1051                         break;
1052
1053 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1054                 case COMPAT_PTRACE_GETHBPREGS:
1055                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1056                         break;
1057
1058                 case COMPAT_PTRACE_SETHBPREGS:
1059                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1060                         break;
1061 #endif
1062
1063                 default:
1064                         ret = compat_ptrace_request(child, request, addr,
1065                                                     data);
1066                         break;
1067         }
1068
1069         return ret;
1070 }
1071 #endif /* CONFIG_COMPAT */
1072
1073 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1074 {
1075 #ifdef CONFIG_COMPAT
1076         if (is_compat_thread(task_thread_info(task)))
1077                 return &user_aarch32_view;
1078 #endif
1079         return &user_aarch64_view;
1080 }
1081
1082 long arch_ptrace(struct task_struct *child, long request,
1083                  unsigned long addr, unsigned long data)
1084 {
1085         return ptrace_request(child, request, addr, data);
1086 }
1087
1088 enum ptrace_syscall_dir {
1089         PTRACE_SYSCALL_ENTER = 0,
1090         PTRACE_SYSCALL_EXIT,
1091 };
1092
1093 static void tracehook_report_syscall(struct pt_regs *regs,
1094                                      enum ptrace_syscall_dir dir)
1095 {
1096         int regno;
1097         unsigned long saved_reg;
1098
1099         /*
1100          * A scratch register (ip(r12) on AArch32, x7 on AArch64) is
1101          * used to denote syscall entry/exit:
1102          */
1103         regno = (is_compat_task() ? 12 : 7);
1104         saved_reg = regs->regs[regno];
1105         regs->regs[regno] = dir;
1106
1107         if (dir == PTRACE_SYSCALL_EXIT)
1108                 tracehook_report_syscall_exit(regs, 0);
1109         else if (tracehook_report_syscall_entry(regs))
1110                 regs->syscallno = ~0UL;
1111
1112         regs->regs[regno] = saved_reg;
1113 }
1114
1115 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
1116 {
1117         if (test_thread_flag(TIF_SYSCALL_TRACE))
1118                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1119
1120         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1121                 trace_sys_enter(regs, regs->syscallno);
1122
1123         audit_syscall_entry(syscall_get_arch(), regs->syscallno,
1124                 regs->orig_x0, regs->regs[1], regs->regs[2], regs->regs[3]);
1125
1126         return regs->syscallno;
1127 }
1128
1129 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
1130 {
1131         audit_syscall_exit(regs);
1132
1133         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1134                 trace_sys_exit(regs, regs_return_value(regs));
1135
1136         if (test_thread_flag(TIF_SYSCALL_TRACE))
1137                 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1138 }