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/kernel.h>
  23 #include <linux/sched.h>
  24 #include <linux/mm.h>
  25 #include <linux/smp.h>
  26 #include <linux/ptrace.h>
  27 #include <linux/user.h>
  28 #include <linux/security.h>
  29 #include <linux/init.h>
  30 #include <linux/signal.h>
  31 #include <linux/uaccess.h>
  32 #include <linux/perf_event.h>
  33 #include <linux/hw_breakpoint.h>
  34 #include <linux/regset.h>
  35 #include <linux/tracehook.h>
  36 #include <linux/elf.h>
  37
  38 #include <asm/compat.h>
  39 #include <asm/debug-monitors.h>
  40 #include <asm/pgtable.h>
  41 #include <asm/traps.h>
  42 #include <asm/system_misc.h>
  43
  44 /*
  45  * TODO: does not yet catch signals sent when the child dies.
  46  * in exit.c or in signal.c.
  47  */
  48
  49 /*
  50  * Called by kernel/ptrace.c when detaching..
  51  */
  52 void ptrace_disable(struct task_struct *child)
  53 {
  54 }
  55
  56 /*
  57  * Handle hitting a breakpoint.
  58  */
  59 static int ptrace_break(struct pt_regs *regs)
  60 {
  61         siginfo_t info = {
  62                 .si_signo = SIGTRAP,
  63                 .si_errno = 0,
  64                 .si_code  = TRAP_BRKPT,
  65                 .si_addr  = (void __user *)instruction_pointer(regs),
  66         };
  67
  68         force_sig_info(SIGTRAP, &info, current);
  69         return 0;
  70 }
  71
  72 static int arm64_break_trap(unsigned long addr, unsigned int esr,
  73                             struct pt_regs *regs)
  74 {
  75         return ptrace_break(regs);
  76 }
  77
  78 #ifdef CONFIG_HAVE_HW_BREAKPOINT
  79 /*
  80  * Handle hitting a HW-breakpoint.
  81  */
  82 static void ptrace_hbptriggered(struct perf_event *bp,
  83                                 struct perf_sample_data *data,
  84                                 struct pt_regs *regs)
  85 {
  86         struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
  87         siginfo_t info = {
  88                 .si_signo       = SIGTRAP,
  89                 .si_errno       = 0,
  90                 .si_code        = TRAP_HWBKPT,
  91                 .si_addr        = (void __user *)(bkpt->trigger),
  92         };
  93
  94 #ifdef CONFIG_COMPAT
  95         int i;
  96
  97         if (!is_compat_task())
  98                 goto send_sig;
  99
 100         for (i = 0; i < ARM_MAX_BRP; ++i) {
 101                 if (current->thread.debug.hbp_break[i] == bp) {
 102                         info.si_errno = (i << 1) + 1;
 103                         break;
 104                 }
 105         }
 106         for (i = ARM_MAX_BRP; i < ARM_MAX_HBP_SLOTS && !bp; ++i) {
 107                 if (current->thread.debug.hbp_watch[i] == bp) {
 108                         info.si_errno = -((i << 1) + 1);
 109                         break;
 110                 }
 111         }
 112
 113 send_sig:
 114 #endif
 115         force_sig_info(SIGTRAP, &info, current);
 116 }
 117
 118 /*
 119  * Unregister breakpoints from this task and reset the pointers in
 120  * the thread_struct.
 121  */
 122 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 123 {
 124         int i;
 125         struct thread_struct *t = &tsk->thread;
 126
 127         for (i = 0; i < ARM_MAX_BRP; i++) {
 128                 if (t->debug.hbp_break[i]) {
 129                         unregister_hw_breakpoint(t->debug.hbp_break[i]);
 130                         t->debug.hbp_break[i] = NULL;
 131                 }
 132         }
 133
 134         for (i = 0; i < ARM_MAX_WRP; i++) {
 135                 if (t->debug.hbp_watch[i]) {
 136                         unregister_hw_breakpoint(t->debug.hbp_watch[i]);
 137                         t->debug.hbp_watch[i] = NULL;
 138                 }
 139         }
 140 }
 141
 142 void ptrace_hw_copy_thread(struct task_struct *tsk)
 143 {
 144         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 145 }
 146
 147 static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
 148                                                struct task_struct *tsk,
 149                                                unsigned long idx)
 150 {
 151         struct perf_event *bp = ERR_PTR(-EINVAL);
 152
 153         switch (note_type) {
 154         case NT_ARM_HW_BREAK:
 155                 if (idx < ARM_MAX_BRP)
 156                         bp = tsk->thread.debug.hbp_break[idx];
 157                 break;
 158         case NT_ARM_HW_WATCH:
 159                 if (idx < ARM_MAX_WRP)
 160                         bp = tsk->thread.debug.hbp_watch[idx];
 161                 break;
 162         }
 163
 164         return bp;
 165 }
 166
 167 static int ptrace_hbp_set_event(unsigned int note_type,
 168                                 struct task_struct *tsk,
 169                                 unsigned long idx,
 170                                 struct perf_event *bp)
 171 {
 172         int err = -EINVAL;
 173
 174         switch (note_type) {
 175         case NT_ARM_HW_BREAK:
 176                 if (idx < ARM_MAX_BRP) {
 177                         tsk->thread.debug.hbp_break[idx] = bp;
 178                         err = 0;
 179                 }
 180                 break;
 181         case NT_ARM_HW_WATCH:
 182                 if (idx < ARM_MAX_WRP) {
 183                         tsk->thread.debug.hbp_watch[idx] = bp;
 184                         err = 0;
 185                 }
 186                 break;
 187         }
 188
 189         return err;
 190 }
 191
 192 static struct perf_event *ptrace_hbp_create(unsigned int note_type,
 193                                             struct task_struct *tsk,
 194                                             unsigned long idx)
 195 {
 196         struct perf_event *bp;
 197         struct perf_event_attr attr;
 198         int err, type;
 199
 200         switch (note_type) {
 201         case NT_ARM_HW_BREAK:
 202                 type = HW_BREAKPOINT_X;
 203                 break;
 204         case NT_ARM_HW_WATCH:
 205                 type = HW_BREAKPOINT_RW;
 206                 break;
 207         default:
 208                 return ERR_PTR(-EINVAL);
 209         }
 210
 211         ptrace_breakpoint_init(&attr);
 212
 213         /*
 214          * Initialise fields to sane defaults
 215          * (i.e. values that will pass validation).
 216          */
 217         attr.bp_addr    = 0;
 218         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 219         attr.bp_type    = type;
 220         attr.disabled   = 1;
 221
 222         bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk);
 223         if (IS_ERR(bp))
 224                 return bp;
 225
 226         err = ptrace_hbp_set_event(note_type, tsk, idx, bp);
 227         if (err)
 228                 return ERR_PTR(err);
 229
 230         return bp;
 231 }
 232
 233 static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
 234                                      struct arch_hw_breakpoint_ctrl ctrl,
 235                                      struct perf_event_attr *attr)
 236 {
 237         int err, len, type, disabled = !ctrl.enabled;
 238
 239         if (disabled) {
 240                 len = 0;
 241                 type = HW_BREAKPOINT_EMPTY;
 242         } else {
 243                 err = arch_bp_generic_fields(ctrl, &len, &type);
 244                 if (err)
 245                         return err;
 246
 247                 switch (note_type) {
 248                 case NT_ARM_HW_BREAK:
 249                         if ((type & HW_BREAKPOINT_X) != type)
 250                                 return -EINVAL;
 251                         break;
 252                 case NT_ARM_HW_WATCH:
 253                         if ((type & HW_BREAKPOINT_RW) != type)
 254                                 return -EINVAL;
 255                         break;
 256                 default:
 257                         return -EINVAL;
 258                 }
 259         }
 260
 261         attr->bp_len    = len;
 262         attr->bp_type   = type;
 263         attr->disabled  = disabled;
 264
 265         return 0;
 266 }
 267
 268 static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info)
 269 {
 270         u8 num;
 271         u32 reg = 0;
 272
 273         switch (note_type) {
 274         case NT_ARM_HW_BREAK:
 275                 num = hw_breakpoint_slots(TYPE_INST);
 276                 break;
 277         case NT_ARM_HW_WATCH:
 278                 num = hw_breakpoint_slots(TYPE_DATA);
 279                 break;
 280         default:
 281                 return -EINVAL;
 282         }
 283
 284         reg |= debug_monitors_arch();
 285         reg <<= 8;
 286         reg |= num;
 287
 288         *info = reg;
 289         return 0;
 290 }
 291
 292 static int ptrace_hbp_get_ctrl(unsigned int note_type,
 293                                struct task_struct *tsk,
 294                                unsigned long idx,
 295                                u32 *ctrl)
 296 {
 297         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 298
 299         if (IS_ERR(bp))
 300                 return PTR_ERR(bp);
 301
 302         *ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0;
 303         return 0;
 304 }
 305
 306 static int ptrace_hbp_get_addr(unsigned int note_type,
 307                                struct task_struct *tsk,
 308                                unsigned long idx,
 309                                u64 *addr)
 310 {
 311         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 312
 313         if (IS_ERR(bp))
 314                 return PTR_ERR(bp);
 315
 316         *addr = bp ? bp->attr.bp_addr : 0;
 317         return 0;
 318 }
 319
 320 static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type,
 321                                                         struct task_struct *tsk,
 322                                                         unsigned long idx)
 323 {
 324         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 325
 326         if (!bp)
 327                 bp = ptrace_hbp_create(note_type, tsk, idx);
 328
 329         return bp;
 330 }
 331
 332 static int ptrace_hbp_set_ctrl(unsigned int note_type,
 333                                struct task_struct *tsk,
 334                                unsigned long idx,
 335                                u32 uctrl)
 336 {
 337         int err;
 338         struct perf_event *bp;
 339         struct perf_event_attr attr;
 340         struct arch_hw_breakpoint_ctrl ctrl;
 341
 342         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 343         if (IS_ERR(bp)) {
 344                 err = PTR_ERR(bp);
 345                 return err;
 346         }
 347
 348         attr = bp->attr;
 349         decode_ctrl_reg(uctrl, &ctrl);
 350         err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
 351         if (err)
 352                 return err;
 353
 354         return modify_user_hw_breakpoint(bp, &attr);
 355 }
 356
 357 static int ptrace_hbp_set_addr(unsigned int note_type,
 358                                struct task_struct *tsk,
 359                                unsigned long idx,
 360                                u64 addr)
 361 {
 362         int err;
 363         struct perf_event *bp;
 364         struct perf_event_attr attr;
 365
 366         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 367         if (IS_ERR(bp)) {
 368                 err = PTR_ERR(bp);
 369                 return err;
 370         }
 371
 372         attr = bp->attr;
 373         attr.bp_addr = addr;
 374         err = modify_user_hw_breakpoint(bp, &attr);
 375         return err;
 376 }
 377
 378 #define PTRACE_HBP_ADDR_SZ      sizeof(u64)
 379 #define PTRACE_HBP_CTRL_SZ      sizeof(u32)
 380 #define PTRACE_HBP_PAD_SZ       sizeof(u32)
 381
 382 static int hw_break_get(struct task_struct *target,
 383                         const struct user_regset *regset,
 384                         unsigned int pos, unsigned int count,
 385                         void *kbuf, void __user *ubuf)
 386 {
 387         unsigned int note_type = regset->core_note_type;
 388         int ret, idx = 0, offset, limit;
 389         u32 info, ctrl;
 390         u64 addr;
 391
 392         /* Resource info */
 393         ret = ptrace_hbp_get_resource_info(note_type, &info);
 394         if (ret)
 395                 return ret;
 396
 397         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0,
 398                                   sizeof(info));
 399         if (ret)
 400                 return ret;
 401
 402         /* Pad */
 403         offset = offsetof(struct user_hwdebug_state, pad);
 404         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, offset,
 405                                        offset + PTRACE_HBP_PAD_SZ);
 406         if (ret)
 407                 return ret;
 408
 409         /* (address, ctrl) registers */
 410         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 411         limit = regset->n * regset->size;
 412         while (count && offset < limit) {
 413                 ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
 414                 if (ret)
 415                         return ret;
 416                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr,
 417                                           offset, offset + PTRACE_HBP_ADDR_SZ);
 418                 if (ret)
 419                         return ret;
 420                 offset += PTRACE_HBP_ADDR_SZ;
 421
 422                 ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
 423                 if (ret)
 424                         return ret;
 425                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl,
 426                                           offset, offset + PTRACE_HBP_CTRL_SZ);
 427                 if (ret)
 428                         return ret;
 429                 offset += PTRACE_HBP_CTRL_SZ;
 430
 431                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 432                                                offset,
 433                                                offset + PTRACE_HBP_PAD_SZ);
 434                 if (ret)
 435                         return ret;
 436                 offset += PTRACE_HBP_PAD_SZ;
 437                 idx++;
 438         }
 439
 440         return 0;
 441 }
 442
 443 static int hw_break_set(struct task_struct *target,
 444                         const struct user_regset *regset,
 445                         unsigned int pos, unsigned int count,
 446                         const void *kbuf, const void __user *ubuf)
 447 {
 448         unsigned int note_type = regset->core_note_type;
 449         int ret, idx = 0, offset, limit;
 450         u32 ctrl;
 451         u64 addr;
 452
 453         /* Resource info and pad */
 454         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 455         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset);
 456         if (ret)
 457                 return ret;
 458
 459         /* (address, ctrl) registers */
 460         limit = regset->n * regset->size;
 461         while (count && offset < limit) {
 462                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
 463                                          offset, offset + PTRACE_HBP_ADDR_SZ);
 464                 if (ret)
 465                         return ret;
 466                 ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
 467                 if (ret)
 468                         return ret;
 469                 offset += PTRACE_HBP_ADDR_SZ;
 470
 471                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
 472                                          offset, offset + PTRACE_HBP_CTRL_SZ);
 473                 if (ret)
 474                         return ret;
 475                 ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
 476                 if (ret)
 477                         return ret;
 478                 offset += PTRACE_HBP_CTRL_SZ;
 479
 480                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 481                                                 offset,
 482                                                 offset + PTRACE_HBP_PAD_SZ);
 483                 if (ret)
 484                         return ret;
 485                 offset += PTRACE_HBP_PAD_SZ;
 486                 idx++;
 487         }
 488
 489         return 0;
 490 }
 491 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 492
 493 static int gpr_get(struct task_struct *target,
 494                    const struct user_regset *regset,
 495                    unsigned int pos, unsigned int count,
 496                    void *kbuf, void __user *ubuf)
 497 {
 498         struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
 499         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 500 }
 501
 502 static int gpr_set(struct task_struct *target, const struct user_regset *regset,
 503                    unsigned int pos, unsigned int count,
 504                    const void *kbuf, const void __user *ubuf)
 505 {
 506         int ret;
 507         struct user_pt_regs newregs;
 508
 509         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
 510         if (ret)
 511                 return ret;
 512
 513         if (!valid_user_regs(&newregs))
 514                 return -EINVAL;
 515
 516         task_pt_regs(target)->user_regs = newregs;
 517         return 0;
 518 }
 519
 520 /*
 521  * TODO: update fp accessors for lazy context switching (sync/flush hwstate)
 522  */
 523 static int fpr_get(struct task_struct *target, const struct user_regset *regset,
 524                    unsigned int pos, unsigned int count,
 525                    void *kbuf, void __user *ubuf)
 526 {
 527         struct user_fpsimd_state *uregs;
 528         uregs = &target->thread.fpsimd_state.user_fpsimd;
 529         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 530 }
 531
 532 static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 533                    unsigned int pos, unsigned int count,
 534                    const void *kbuf, const void __user *ubuf)
 535 {
 536         int ret;
 537         struct user_fpsimd_state newstate;
 538
 539         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1);
 540         if (ret)
 541                 return ret;
 542
 543         target->thread.fpsimd_state.user_fpsimd = newstate;
 544         return ret;
 545 }
 546
 547 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 548                    unsigned int pos, unsigned int count,
 549                    void *kbuf, void __user *ubuf)
 550 {
 551         unsigned long *tls = &target->thread.tp_value;
 552         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
 553 }
 554
 555 static int tls_set(struct task_struct *target, const struct user_regset *regset,
 556                    unsigned int pos, unsigned int count,
 557                    const void *kbuf, const void __user *ubuf)
 558 {
 559         int ret;
 560         unsigned long tls;
 561
 562         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 563         if (ret)
 564                 return ret;
 565
 566         target->thread.tp_value = tls;
 567         return ret;
 568 }
 569
 570 enum aarch64_regset {
 571         REGSET_GPR,
 572         REGSET_FPR,
 573         REGSET_TLS,
 574 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 575         REGSET_HW_BREAK,
 576         REGSET_HW_WATCH,
 577 #endif
 578 };
 579
 580 static const struct user_regset aarch64_regsets[] = {
 581         [REGSET_GPR] = {
 582                 .core_note_type = NT_PRSTATUS,
 583                 .n = sizeof(struct user_pt_regs) / sizeof(u64),
 584                 .size = sizeof(u64),
 585                 .align = sizeof(u64),
 586                 .get = gpr_get,
 587                 .set = gpr_set
 588         },
 589         [REGSET_FPR] = {
 590                 .core_note_type = NT_PRFPREG,
 591                 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
 592                 /*
 593                  * We pretend we have 32-bit registers because the fpsr and
 594                  * fpcr are 32-bits wide.
 595                  */
 596                 .size = sizeof(u32),
 597                 .align = sizeof(u32),
 598                 .get = fpr_get,
 599                 .set = fpr_set
 600         },
 601         [REGSET_TLS] = {
 602                 .core_note_type = NT_ARM_TLS,
 603                 .n = 1,
 604                 .size = sizeof(void *),
 605                 .align = sizeof(void *),
 606                 .get = tls_get,
 607                 .set = tls_set,
 608         },
 609 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 610         [REGSET_HW_BREAK] = {
 611                 .core_note_type = NT_ARM_HW_BREAK,
 612                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 613                 .size = sizeof(u32),
 614                 .align = sizeof(u32),
 615                 .get = hw_break_get,
 616                 .set = hw_break_set,
 617         },
 618         [REGSET_HW_WATCH] = {
 619                 .core_note_type = NT_ARM_HW_WATCH,
 620                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 621                 .size = sizeof(u32),
 622                 .align = sizeof(u32),
 623                 .get = hw_break_get,
 624                 .set = hw_break_set,
 625         },
 626 #endif
 627 };
 628
 629 static const struct user_regset_view user_aarch64_view = {
 630         .name = "aarch64", .e_machine = EM_AARCH64,
 631         .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
 632 };
 633
 634 #ifdef CONFIG_COMPAT
 635 #include <linux/compat.h>
 636
 637 enum compat_regset {
 638         REGSET_COMPAT_GPR,
 639         REGSET_COMPAT_VFP,
 640 };
 641
 642 static int compat_gpr_get(struct task_struct *target,
 643                           const struct user_regset *regset,
 644                           unsigned int pos, unsigned int count,
 645                           void *kbuf, void __user *ubuf)
 646 {
 647         int ret = 0;
 648         unsigned int i, start, num_regs;
 649
 650         /* Calculate the number of AArch32 registers contained in count */
 651         num_regs = count / regset->size;
 652
 653         /* Convert pos into an register number */
 654         start = pos / regset->size;
 655
 656         if (start + num_regs > regset->n)
 657                 return -EIO;
 658
 659         for (i = 0; i < num_regs; ++i) {
 660                 unsigned int idx = start + i;
 661                 void *reg;
 662
 663                 switch (idx) {
 664                 case 15:
 665                         reg = (void *)&task_pt_regs(target)->pc;
 666                         break;
 667                 case 16:
 668                         reg = (void *)&task_pt_regs(target)->pstate;
 669                         break;
 670                 case 17:
 671                         reg = (void *)&task_pt_regs(target)->orig_x0;
 672                         break;
 673                 default:
 674                         reg = (void *)&task_pt_regs(target)->regs[idx];
 675                 }
 676
 677                 ret = copy_to_user(ubuf, reg, sizeof(compat_ulong_t));
 678
 679                 if (ret)
 680                         break;
 681                 else
 682                         ubuf += sizeof(compat_ulong_t);
 683         }
 684
 685         return ret;
 686 }
 687
 688 static int compat_gpr_set(struct task_struct *target,
 689                           const struct user_regset *regset,
 690                           unsigned int pos, unsigned int count,
 691                           const void *kbuf, const void __user *ubuf)
 692 {
 693         struct pt_regs newregs;
 694         int ret = 0;
 695         unsigned int i, start, num_regs;
 696
 697         /* Calculate the number of AArch32 registers contained in count */
 698         num_regs = count / regset->size;
 699
 700         /* Convert pos into an register number */
 701         start = pos / regset->size;
 702
 703         if (start + num_regs > regset->n)
 704                 return -EIO;
 705
 706         newregs = *task_pt_regs(target);
 707
 708         for (i = 0; i < num_regs; ++i) {
 709                 unsigned int idx = start + i;
 710                 void *reg;
 711
 712                 switch (idx) {
 713                 case 15:
 714                         reg = (void *)&newregs.pc;
 715                         break;
 716                 case 16:
 717                         reg = (void *)&newregs.pstate;
 718                         break;
 719                 case 17:
 720                         reg = (void *)&newregs.orig_x0;
 721                         break;
 722                 default:
 723                         reg = (void *)&newregs.regs[idx];
 724                 }
 725
 726                 ret = copy_from_user(reg, ubuf, sizeof(compat_ulong_t));
 727
 728                 if (ret)
 729                         goto out;
 730                 else
 731                         ubuf += sizeof(compat_ulong_t);
 732         }
 733
 734         if (valid_user_regs(&newregs.user_regs))
 735                 *task_pt_regs(target) = newregs;
 736         else
 737                 ret = -EINVAL;
 738
 739 out:
 740         return ret;
 741 }
 742
 743 static int compat_vfp_get(struct task_struct *target,
 744                           const struct user_regset *regset,
 745                           unsigned int pos, unsigned int count,
 746                           void *kbuf, void __user *ubuf)
 747 {
 748         struct user_fpsimd_state *uregs;
 749         compat_ulong_t fpscr;
 750         int ret;
 751
 752         uregs = &target->thread.fpsimd_state.user_fpsimd;
 753
 754         /*
 755          * The VFP registers are packed into the fpsimd_state, so they all sit
 756          * nicely together for us. We just need to create the fpscr separately.
 757          */
 758         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
 759                                   VFP_STATE_SIZE - sizeof(compat_ulong_t));
 760
 761         if (count && !ret) {
 762                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
 763                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
 764                 ret = put_user(fpscr, (compat_ulong_t *)ubuf);
 765         }
 766
 767         return ret;
 768 }
 769
 770 static int compat_vfp_set(struct task_struct *target,
 771                           const struct user_regset *regset,
 772                           unsigned int pos, unsigned int count,
 773                           const void *kbuf, const void __user *ubuf)
 774 {
 775         struct user_fpsimd_state *uregs;
 776         compat_ulong_t fpscr;
 777         int ret;
 778
 779         if (pos + count > VFP_STATE_SIZE)
 780                 return -EIO;
 781
 782         uregs = &target->thread.fpsimd_state.user_fpsimd;
 783
 784         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
 785                                  VFP_STATE_SIZE - sizeof(compat_ulong_t));
 786
 787         if (count && !ret) {
 788                 ret = get_user(fpscr, (compat_ulong_t *)ubuf);
 789                 uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
 790                 uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
 791         }
 792
 793         return ret;
 794 }
 795
 796 static const struct user_regset aarch32_regsets[] = {
 797         [REGSET_COMPAT_GPR] = {
 798                 .core_note_type = NT_PRSTATUS,
 799                 .n = COMPAT_ELF_NGREG,
 800                 .size = sizeof(compat_elf_greg_t),
 801                 .align = sizeof(compat_elf_greg_t),
 802                 .get = compat_gpr_get,
 803                 .set = compat_gpr_set
 804         },
 805         [REGSET_COMPAT_VFP] = {
 806                 .core_note_type = NT_ARM_VFP,
 807                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
 808                 .size = sizeof(compat_ulong_t),
 809                 .align = sizeof(compat_ulong_t),
 810                 .get = compat_vfp_get,
 811                 .set = compat_vfp_set
 812         },
 813 };
 814
 815 static const struct user_regset_view user_aarch32_view = {
 816         .name = "aarch32", .e_machine = EM_ARM,
 817         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
 818 };
 819
 820 int aarch32_break_trap(struct pt_regs *regs)
 821 {
 822         unsigned int instr;
 823         bool bp = false;
 824         void __user *pc = (void __user *)instruction_pointer(regs);
 825
 826         if (compat_thumb_mode(regs)) {
 827                 /* get 16-bit Thumb instruction */
 828                 get_user(instr, (u16 __user *)pc);
 829                 if (instr == AARCH32_BREAK_THUMB2_LO) {
 830                         /* get second half of 32-bit Thumb-2 instruction */
 831                         get_user(instr, (u16 __user *)(pc + 2));
 832                         bp = instr == AARCH32_BREAK_THUMB2_HI;
 833                 } else {
 834                         bp = instr == AARCH32_BREAK_THUMB;
 835                 }
 836         } else {
 837                 /* 32-bit ARM instruction */
 838                 get_user(instr, (u32 __user *)pc);
 839                 bp = (instr & ~0xf0000000) == AARCH32_BREAK_ARM;
 840         }
 841
 842         if (bp)
 843                 return ptrace_break(regs);
 844         return 1;
 845 }
 846
 847 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
 848                                    compat_ulong_t __user *ret)
 849 {
 850         compat_ulong_t tmp;
 851
 852         if (off & 3)
 853                 return -EIO;
 854
 855         if (off == COMPAT_PT_TEXT_ADDR)
 856                 tmp = tsk->mm->start_code;
 857         else if (off == COMPAT_PT_DATA_ADDR)
 858                 tmp = tsk->mm->start_data;
 859         else if (off == COMPAT_PT_TEXT_END_ADDR)
 860                 tmp = tsk->mm->end_code;
 861         else if (off < sizeof(compat_elf_gregset_t))
 862                 return copy_regset_to_user(tsk, &user_aarch32_view,
 863                                            REGSET_COMPAT_GPR, off,
 864                                            sizeof(compat_ulong_t), ret);
 865         else if (off >= COMPAT_USER_SZ)
 866                 return -EIO;
 867         else
 868                 tmp = 0;
 869
 870         return put_user(tmp, ret);
 871 }
 872
 873 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
 874                                     compat_ulong_t val)
 875 {
 876         int ret;
 877
 878         if (off & 3 || off >= COMPAT_USER_SZ)
 879                 return -EIO;
 880
 881         if (off >= sizeof(compat_elf_gregset_t))
 882                 return 0;
 883
 884         ret = copy_regset_from_user(tsk, &user_aarch32_view,
 885                                     REGSET_COMPAT_GPR, off,
 886                                     sizeof(compat_ulong_t),
 887                                     &val);
 888         return ret;
 889 }
 890
 891 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 892
 893 /*
 894  * Convert a virtual register number into an index for a thread_info
 895  * breakpoint array. Breakpoints are identified using positive numbers
 896  * whilst watchpoints are negative. The registers are laid out as pairs
 897  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
 898  * Register 0 is reserved for describing resource information.
 899  */
 900 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
 901 {
 902         return (abs(num) - 1) >> 1;
 903 }
 904
 905 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
 906 {
 907         u8 num_brps, num_wrps, debug_arch, wp_len;
 908         u32 reg = 0;
 909
 910         num_brps        = hw_breakpoint_slots(TYPE_INST);
 911         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
 912
 913         debug_arch      = debug_monitors_arch();
 914         wp_len          = 8;
 915         reg             |= debug_arch;
 916         reg             <<= 8;
 917         reg             |= wp_len;
 918         reg             <<= 8;
 919         reg             |= num_wrps;
 920         reg             <<= 8;
 921         reg             |= num_brps;
 922
 923         *kdata = reg;
 924         return 0;
 925 }
 926
 927 static int compat_ptrace_hbp_get(unsigned int note_type,
 928                                  struct task_struct *tsk,
 929                                  compat_long_t num,
 930                                  u32 *kdata)
 931 {
 932         u64 addr = 0;
 933         u32 ctrl = 0;
 934
 935         int err, idx = compat_ptrace_hbp_num_to_idx(num);;
 936
 937         if (num & 1) {
 938                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
 939                 *kdata = (u32)addr;
 940         } else {
 941                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
 942                 *kdata = ctrl;
 943         }
 944
 945         return err;
 946 }
 947
 948 static int compat_ptrace_hbp_set(unsigned int note_type,
 949                                  struct task_struct *tsk,
 950                                  compat_long_t num,
 951                                  u32 *kdata)
 952 {
 953         u64 addr;
 954         u32 ctrl;
 955
 956         int err, idx = compat_ptrace_hbp_num_to_idx(num);
 957
 958         if (num & 1) {
 959                 addr = *kdata;
 960                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
 961         } else {
 962                 ctrl = *kdata;
 963                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
 964         }
 965
 966         return err;
 967 }
 968
 969 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
 970                                     compat_ulong_t __user *data)
 971 {
 972         int ret;
 973         u32 kdata;
 974         mm_segment_t old_fs = get_fs();
 975
 976         set_fs(KERNEL_DS);
 977         /* Watchpoint */
 978         if (num < 0) {
 979                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
 980         /* Resource info */
 981         } else if (num == 0) {
 982                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
 983         /* Breakpoint */
 984         } else {
 985                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
 986         }
 987         set_fs(old_fs);
 988
 989         if (!ret)
 990                 ret = put_user(kdata, data);
 991
 992         return ret;
 993 }
 994
 995 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
 996                                     compat_ulong_t __user *data)
 997 {
 998         int ret;
 999         u32 kdata = 0;
1000         mm_segment_t old_fs = get_fs();
1001
1002         if (num == 0)
1003                 return 0;
1004
1005         ret = get_user(kdata, data);
1006         if (ret)
1007                 return ret;
1008
1009         set_fs(KERNEL_DS);
1010         if (num < 0)
1011                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
1012         else
1013                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
1014         set_fs(old_fs);
1015
1016         return ret;
1017 }
1018 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
1019
1020 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1021                         compat_ulong_t caddr, compat_ulong_t cdata)
1022 {
1023         unsigned long addr = caddr;
1024         unsigned long data = cdata;
1025         void __user *datap = compat_ptr(data);
1026         int ret;
1027
1028         switch (request) {
1029                 case PTRACE_PEEKUSR:
1030                         ret = compat_ptrace_read_user(child, addr, datap);
1031                         break;
1032
1033                 case PTRACE_POKEUSR:
1034                         ret = compat_ptrace_write_user(child, addr, data);
1035                         break;
1036
1037                 case COMPAT_PTRACE_GETREGS:
1038                         ret = copy_regset_to_user(child,
1039                                                   &user_aarch32_view,
1040                                                   REGSET_COMPAT_GPR,
1041                                                   0, sizeof(compat_elf_gregset_t),
1042                                                   datap);
1043                         break;
1044
1045                 case COMPAT_PTRACE_SETREGS:
1046                         ret = copy_regset_from_user(child,
1047                                                     &user_aarch32_view,
1048                                                     REGSET_COMPAT_GPR,
1049                                                     0, sizeof(compat_elf_gregset_t),
1050                                                     datap);
1051                         break;
1052
1053                 case COMPAT_PTRACE_GET_THREAD_AREA:
1054                         ret = put_user((compat_ulong_t)child->thread.tp_value,
1055                                        (compat_ulong_t __user *)datap);
1056                         break;
1057
1058                 case COMPAT_PTRACE_SET_SYSCALL:
1059                         task_pt_regs(child)->syscallno = data;
1060                         ret = 0;
1061                         break;
1062
1063                 case COMPAT_PTRACE_GETVFPREGS:
1064                         ret = copy_regset_to_user(child,
1065                                                   &user_aarch32_view,
1066                                                   REGSET_COMPAT_VFP,
1067                                                   0, VFP_STATE_SIZE,
1068                                                   datap);
1069                         break;
1070
1071                 case COMPAT_PTRACE_SETVFPREGS:
1072                         ret = copy_regset_from_user(child,
1073                                                     &user_aarch32_view,
1074                                                     REGSET_COMPAT_VFP,
1075                                                     0, VFP_STATE_SIZE,
1076                                                     datap);
1077                         break;
1078
1079 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1080                 case COMPAT_PTRACE_GETHBPREGS:
1081                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1082                         break;
1083
1084                 case COMPAT_PTRACE_SETHBPREGS:
1085                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1086                         break;
1087 #endif
1088
1089                 default:
1090                         ret = compat_ptrace_request(child, request, addr,
1091                                                     data);
1092                         break;
1093         }
1094
1095         return ret;
1096 }
1097 #endif /* CONFIG_COMPAT */
1098
1099 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1100 {
1101 #ifdef CONFIG_COMPAT
1102         if (is_compat_thread(task_thread_info(task)))
1103                 return &user_aarch32_view;
1104 #endif
1105         return &user_aarch64_view;
1106 }
1107
1108 long arch_ptrace(struct task_struct *child, long request,
1109                  unsigned long addr, unsigned long data)
1110 {
1111         return ptrace_request(child, request, addr, data);
1112 }
1113
1114
1115 static int __init ptrace_break_init(void)
1116 {
1117         hook_debug_fault_code(DBG_ESR_EVT_BRK, arm64_break_trap, SIGTRAP,
1118                               TRAP_BRKPT, "ptrace BRK handler");
1119         return 0;
1120 }
1121 core_initcall(ptrace_break_init);
1122
1123
1124 asmlinkage int syscall_trace(int dir, struct pt_regs *regs)
1125 {
1126         unsigned long saved_reg;
1127
1128         if (!test_thread_flag(TIF_SYSCALL_TRACE))
1129                 return regs->syscallno;
1130
1131         if (is_compat_task()) {
1132                 /* AArch32 uses ip (r12) for scratch */
1133                 saved_reg = regs->regs[12];
1134                 regs->regs[12] = dir;
1135         } else {
1136                 /*
1137                  * Save X7. X7 is used to denote syscall entry/exit:
1138                  *   X7 = 0 -> entry, = 1 -> exit
1139                  */
1140                 saved_reg = regs->regs[7];
1141                 regs->regs[7] = dir;
1142         }
1143
1144         if (dir)
1145                 tracehook_report_syscall_exit(regs, 0);
1146         else if (tracehook_report_syscall_entry(regs))
1147                 regs->syscallno = ~0UL;
1148
1149         if (is_compat_task())
1150                 regs->regs[12] = saved_reg;
1151         else
1152                 regs->regs[7] = saved_reg;
1153
1154         return regs->syscallno;
1155 }