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/signal.h>
  26 #include <linux/sched/task_stack.h>
  27 #include <linux/mm.h>
  28 #include <linux/nospec.h>
  29 #include <linux/smp.h>
  30 #include <linux/ptrace.h>
  31 #include <linux/user.h>
  32 #include <linux/seccomp.h>
  33 #include <linux/security.h>
  34 #include <linux/init.h>
  35 #include <linux/signal.h>
  36 #include <linux/uaccess.h>
  37 #include <linux/perf_event.h>
  38 #include <linux/hw_breakpoint.h>
  39 #include <linux/regset.h>
  40 #include <linux/tracehook.h>
  41 #include <linux/elf.h>
  42
  43 #include <asm/compat.h>
  44 #include <asm/debug-monitors.h>
  45 #include <asm/pgtable.h>
  46 #include <asm/stacktrace.h>
  47 #include <asm/syscall.h>
  48 #include <asm/traps.h>
  49 #include <asm/system_misc.h>
  50
  51 #define CREATE_TRACE_POINTS
  52 #include <trace/events/syscalls.h>
  53
  54 struct pt_regs_offset {
  55         const char *name;
  56         int offset;
  57 };
  58
  59 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  60 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  61 #define GPR_OFFSET_NAME(r) \
  62         {.name = "x" #r, .offset = offsetof(struct pt_regs, regs[r])}
  63
  64 static const struct pt_regs_offset regoffset_table[] = {
  65         GPR_OFFSET_NAME(0),
  66         GPR_OFFSET_NAME(1),
  67         GPR_OFFSET_NAME(2),
  68         GPR_OFFSET_NAME(3),
  69         GPR_OFFSET_NAME(4),
  70         GPR_OFFSET_NAME(5),
  71         GPR_OFFSET_NAME(6),
  72         GPR_OFFSET_NAME(7),
  73         GPR_OFFSET_NAME(8),
  74         GPR_OFFSET_NAME(9),
  75         GPR_OFFSET_NAME(10),
  76         GPR_OFFSET_NAME(11),
  77         GPR_OFFSET_NAME(12),
  78         GPR_OFFSET_NAME(13),
  79         GPR_OFFSET_NAME(14),
  80         GPR_OFFSET_NAME(15),
  81         GPR_OFFSET_NAME(16),
  82         GPR_OFFSET_NAME(17),
  83         GPR_OFFSET_NAME(18),
  84         GPR_OFFSET_NAME(19),
  85         GPR_OFFSET_NAME(20),
  86         GPR_OFFSET_NAME(21),
  87         GPR_OFFSET_NAME(22),
  88         GPR_OFFSET_NAME(23),
  89         GPR_OFFSET_NAME(24),
  90         GPR_OFFSET_NAME(25),
  91         GPR_OFFSET_NAME(26),
  92         GPR_OFFSET_NAME(27),
  93         GPR_OFFSET_NAME(28),
  94         GPR_OFFSET_NAME(29),
  95         GPR_OFFSET_NAME(30),
  96         {.name = "lr", .offset = offsetof(struct pt_regs, regs[30])},
  97         REG_OFFSET_NAME(sp),
  98         REG_OFFSET_NAME(pc),
  99         REG_OFFSET_NAME(pstate),
 100         REG_OFFSET_END,
 101 };
 102
 103 /**
 104  * regs_query_register_offset() - query register offset from its name
 105  * @name:       the name of a register
 106  *
 107  * regs_query_register_offset() returns the offset of a register in struct
 108  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 109  */
 110 int regs_query_register_offset(const char *name)
 111 {
 112         const struct pt_regs_offset *roff;
 113
 114         for (roff = regoffset_table; roff->name != NULL; roff++)
 115                 if (!strcmp(roff->name, name))
 116                         return roff->offset;
 117         return -EINVAL;
 118 }
 119
 120 /**
 121  * regs_within_kernel_stack() - check the address in the stack
 122  * @regs:      pt_regs which contains kernel stack pointer.
 123  * @addr:      address which is checked.
 124  *
 125  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 126  * If @addr is within the kernel stack, it returns true. If not, returns false.
 127  */
 128 static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 129 {
 130         return ((addr & ~(THREAD_SIZE - 1))  ==
 131                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))) ||
 132                 on_irq_stack(addr);
 133 }
 134
 135 /**
 136  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 137  * @regs:       pt_regs which contains kernel stack pointer.
 138  * @n:          stack entry number.
 139  *
 140  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 141  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 142  * this returns 0.
 143  */
 144 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 145 {
 146         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 147
 148         addr += n;
 149         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 150                 return *addr;
 151         else
 152                 return 0;
 153 }
 154
 155 /*
 156  * TODO: does not yet catch signals sent when the child dies.
 157  * in exit.c or in signal.c.
 158  */
 159
 160 /*
 161  * Called by kernel/ptrace.c when detaching..
 162  */
 163 void ptrace_disable(struct task_struct *child)
 164 {
 165         /*
 166          * This would be better off in core code, but PTRACE_DETACH has
 167          * grown its fair share of arch-specific worts and changing it
 168          * is likely to cause regressions on obscure architectures.
 169          */
 170         user_disable_single_step(child);
 171 }
 172
 173 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 174 /*
 175  * Handle hitting a HW-breakpoint.
 176  */
 177 static void ptrace_hbptriggered(struct perf_event *bp,
 178                                 struct perf_sample_data *data,
 179                                 struct pt_regs *regs)
 180 {
 181         struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
 182         siginfo_t info = {
 183                 .si_signo       = SIGTRAP,
 184                 .si_errno       = 0,
 185                 .si_code        = TRAP_HWBKPT,
 186                 .si_addr        = (void __user *)(bkpt->trigger),
 187         };
 188
 189 #ifdef CONFIG_COMPAT
 190         int i;
 191
 192         if (!is_compat_task())
 193                 goto send_sig;
 194
 195         for (i = 0; i < ARM_MAX_BRP; ++i) {
 196                 if (current->thread.debug.hbp_break[i] == bp) {
 197                         info.si_errno = (i << 1) + 1;
 198                         break;
 199                 }
 200         }
 201
 202         for (i = 0; i < ARM_MAX_WRP; ++i) {
 203                 if (current->thread.debug.hbp_watch[i] == bp) {
 204                         info.si_errno = -((i << 1) + 1);
 205                         break;
 206                 }
 207         }
 208
 209 send_sig:
 210 #endif
 211         force_sig_info(SIGTRAP, &info, current);
 212 }
 213
 214 /*
 215  * Unregister breakpoints from this task and reset the pointers in
 216  * the thread_struct.
 217  */
 218 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 219 {
 220         int i;
 221         struct thread_struct *t = &tsk->thread;
 222
 223         for (i = 0; i < ARM_MAX_BRP; i++) {
 224                 if (t->debug.hbp_break[i]) {
 225                         unregister_hw_breakpoint(t->debug.hbp_break[i]);
 226                         t->debug.hbp_break[i] = NULL;
 227                 }
 228         }
 229
 230         for (i = 0; i < ARM_MAX_WRP; i++) {
 231                 if (t->debug.hbp_watch[i]) {
 232                         unregister_hw_breakpoint(t->debug.hbp_watch[i]);
 233                         t->debug.hbp_watch[i] = NULL;
 234                 }
 235         }
 236 }
 237
 238 void ptrace_hw_copy_thread(struct task_struct *tsk)
 239 {
 240         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 241 }
 242
 243 static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
 244                                                struct task_struct *tsk,
 245                                                unsigned long idx)
 246 {
 247         struct perf_event *bp = ERR_PTR(-EINVAL);
 248
 249         switch (note_type) {
 250         case NT_ARM_HW_BREAK:
 251                 if (idx >= ARM_MAX_BRP)
 252                         goto out;
 253                 idx = array_index_nospec(idx, ARM_MAX_BRP);
 254                 bp = tsk->thread.debug.hbp_break[idx];
 255                 break;
 256         case NT_ARM_HW_WATCH:
 257                 if (idx >= ARM_MAX_WRP)
 258                         goto out;
 259                 idx = array_index_nospec(idx, ARM_MAX_WRP);
 260                 bp = tsk->thread.debug.hbp_watch[idx];
 261                 break;
 262         }
 263
 264 out:
 265         return bp;
 266 }
 267
 268 static int ptrace_hbp_set_event(unsigned int note_type,
 269                                 struct task_struct *tsk,
 270                                 unsigned long idx,
 271                                 struct perf_event *bp)
 272 {
 273         int err = -EINVAL;
 274
 275         switch (note_type) {
 276         case NT_ARM_HW_BREAK:
 277                 if (idx >= ARM_MAX_BRP)
 278                         goto out;
 279                 idx = array_index_nospec(idx, ARM_MAX_BRP);
 280                 tsk->thread.debug.hbp_break[idx] = bp;
 281                 err = 0;
 282                 break;
 283         case NT_ARM_HW_WATCH:
 284                 if (idx >= ARM_MAX_WRP)
 285                         goto out;
 286                 idx = array_index_nospec(idx, ARM_MAX_WRP);
 287                 tsk->thread.debug.hbp_watch[idx] = bp;
 288                 err = 0;
 289                 break;
 290         }
 291
 292 out:
 293         return err;
 294 }
 295
 296 static struct perf_event *ptrace_hbp_create(unsigned int note_type,
 297                                             struct task_struct *tsk,
 298                                             unsigned long idx)
 299 {
 300         struct perf_event *bp;
 301         struct perf_event_attr attr;
 302         int err, type;
 303
 304         switch (note_type) {
 305         case NT_ARM_HW_BREAK:
 306                 type = HW_BREAKPOINT_X;
 307                 break;
 308         case NT_ARM_HW_WATCH:
 309                 type = HW_BREAKPOINT_RW;
 310                 break;
 311         default:
 312                 return ERR_PTR(-EINVAL);
 313         }
 314
 315         ptrace_breakpoint_init(&attr);
 316
 317         /*
 318          * Initialise fields to sane defaults
 319          * (i.e. values that will pass validation).
 320          */
 321         attr.bp_addr    = 0;
 322         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 323         attr.bp_type    = type;
 324         attr.disabled   = 1;
 325
 326         bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk);
 327         if (IS_ERR(bp))
 328                 return bp;
 329
 330         err = ptrace_hbp_set_event(note_type, tsk, idx, bp);
 331         if (err)
 332                 return ERR_PTR(err);
 333
 334         return bp;
 335 }
 336
 337 static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
 338                                      struct arch_hw_breakpoint_ctrl ctrl,
 339                                      struct perf_event_attr *attr)
 340 {
 341         int err, len, type, offset, disabled = !ctrl.enabled;
 342
 343         attr->disabled = disabled;
 344         if (disabled)
 345                 return 0;
 346
 347         err = arch_bp_generic_fields(ctrl, &len, &type, &offset);
 348         if (err)
 349                 return err;
 350
 351         switch (note_type) {
 352         case NT_ARM_HW_BREAK:
 353                 if ((type & HW_BREAKPOINT_X) != type)
 354                         return -EINVAL;
 355                 break;
 356         case NT_ARM_HW_WATCH:
 357                 if ((type & HW_BREAKPOINT_RW) != type)
 358                         return -EINVAL;
 359                 break;
 360         default:
 361                 return -EINVAL;
 362         }
 363
 364         attr->bp_len    = len;
 365         attr->bp_type   = type;
 366         attr->bp_addr   += offset;
 367
 368         return 0;
 369 }
 370
 371 static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info)
 372 {
 373         u8 num;
 374         u32 reg = 0;
 375
 376         switch (note_type) {
 377         case NT_ARM_HW_BREAK:
 378                 num = hw_breakpoint_slots(TYPE_INST);
 379                 break;
 380         case NT_ARM_HW_WATCH:
 381                 num = hw_breakpoint_slots(TYPE_DATA);
 382                 break;
 383         default:
 384                 return -EINVAL;
 385         }
 386
 387         reg |= debug_monitors_arch();
 388         reg <<= 8;
 389         reg |= num;
 390
 391         *info = reg;
 392         return 0;
 393 }
 394
 395 static int ptrace_hbp_get_ctrl(unsigned int note_type,
 396                                struct task_struct *tsk,
 397                                unsigned long idx,
 398                                u32 *ctrl)
 399 {
 400         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 401
 402         if (IS_ERR(bp))
 403                 return PTR_ERR(bp);
 404
 405         *ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0;
 406         return 0;
 407 }
 408
 409 static int ptrace_hbp_get_addr(unsigned int note_type,
 410                                struct task_struct *tsk,
 411                                unsigned long idx,
 412                                u64 *addr)
 413 {
 414         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 415
 416         if (IS_ERR(bp))
 417                 return PTR_ERR(bp);
 418
 419         *addr = bp ? counter_arch_bp(bp)->address : 0;
 420         return 0;
 421 }
 422
 423 static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type,
 424                                                         struct task_struct *tsk,
 425                                                         unsigned long idx)
 426 {
 427         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 428
 429         if (!bp)
 430                 bp = ptrace_hbp_create(note_type, tsk, idx);
 431
 432         return bp;
 433 }
 434
 435 static int ptrace_hbp_set_ctrl(unsigned int note_type,
 436                                struct task_struct *tsk,
 437                                unsigned long idx,
 438                                u32 uctrl)
 439 {
 440         int err;
 441         struct perf_event *bp;
 442         struct perf_event_attr attr;
 443         struct arch_hw_breakpoint_ctrl ctrl;
 444
 445         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 446         if (IS_ERR(bp)) {
 447                 err = PTR_ERR(bp);
 448                 return err;
 449         }
 450
 451         attr = bp->attr;
 452         decode_ctrl_reg(uctrl, &ctrl);
 453         err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
 454         if (err)
 455                 return err;
 456
 457         return modify_user_hw_breakpoint(bp, &attr);
 458 }
 459
 460 static int ptrace_hbp_set_addr(unsigned int note_type,
 461                                struct task_struct *tsk,
 462                                unsigned long idx,
 463                                u64 addr)
 464 {
 465         int err;
 466         struct perf_event *bp;
 467         struct perf_event_attr attr;
 468
 469         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 470         if (IS_ERR(bp)) {
 471                 err = PTR_ERR(bp);
 472                 return err;
 473         }
 474
 475         attr = bp->attr;
 476         attr.bp_addr = addr;
 477         err = modify_user_hw_breakpoint(bp, &attr);
 478         return err;
 479 }
 480
 481 #define PTRACE_HBP_ADDR_SZ      sizeof(u64)
 482 #define PTRACE_HBP_CTRL_SZ      sizeof(u32)
 483 #define PTRACE_HBP_PAD_SZ       sizeof(u32)
 484
 485 static int hw_break_get(struct task_struct *target,
 486                         const struct user_regset *regset,
 487                         unsigned int pos, unsigned int count,
 488                         void *kbuf, void __user *ubuf)
 489 {
 490         unsigned int note_type = regset->core_note_type;
 491         int ret, idx = 0, offset, limit;
 492         u32 info, ctrl;
 493         u64 addr;
 494
 495         /* Resource info */
 496         ret = ptrace_hbp_get_resource_info(note_type, &info);
 497         if (ret)
 498                 return ret;
 499
 500         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0,
 501                                   sizeof(info));
 502         if (ret)
 503                 return ret;
 504
 505         /* Pad */
 506         offset = offsetof(struct user_hwdebug_state, pad);
 507         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, offset,
 508                                        offset + PTRACE_HBP_PAD_SZ);
 509         if (ret)
 510                 return ret;
 511
 512         /* (address, ctrl) registers */
 513         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 514         limit = regset->n * regset->size;
 515         while (count && offset < limit) {
 516                 ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
 517                 if (ret)
 518                         return ret;
 519                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr,
 520                                           offset, offset + PTRACE_HBP_ADDR_SZ);
 521                 if (ret)
 522                         return ret;
 523                 offset += PTRACE_HBP_ADDR_SZ;
 524
 525                 ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
 526                 if (ret)
 527                         return ret;
 528                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl,
 529                                           offset, offset + PTRACE_HBP_CTRL_SZ);
 530                 if (ret)
 531                         return ret;
 532                 offset += PTRACE_HBP_CTRL_SZ;
 533
 534                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 535                                                offset,
 536                                                offset + PTRACE_HBP_PAD_SZ);
 537                 if (ret)
 538                         return ret;
 539                 offset += PTRACE_HBP_PAD_SZ;
 540                 idx++;
 541         }
 542
 543         return 0;
 544 }
 545
 546 static int hw_break_set(struct task_struct *target,
 547                         const struct user_regset *regset,
 548                         unsigned int pos, unsigned int count,
 549                         const void *kbuf, const void __user *ubuf)
 550 {
 551         unsigned int note_type = regset->core_note_type;
 552         int ret, idx = 0, offset, limit;
 553         u32 ctrl;
 554         u64 addr;
 555
 556         /* Resource info and pad */
 557         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 558         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset);
 559         if (ret)
 560                 return ret;
 561
 562         /* (address, ctrl) registers */
 563         limit = regset->n * regset->size;
 564         while (count && offset < limit) {
 565                 if (count < PTRACE_HBP_ADDR_SZ)
 566                         return -EINVAL;
 567                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
 568                                          offset, offset + PTRACE_HBP_ADDR_SZ);
 569                 if (ret)
 570                         return ret;
 571                 ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
 572                 if (ret)
 573                         return ret;
 574                 offset += PTRACE_HBP_ADDR_SZ;
 575
 576                 if (!count)
 577                         break;
 578                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
 579                                          offset, offset + PTRACE_HBP_CTRL_SZ);
 580                 if (ret)
 581                         return ret;
 582                 ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
 583                 if (ret)
 584                         return ret;
 585                 offset += PTRACE_HBP_CTRL_SZ;
 586
 587                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 588                                                 offset,
 589                                                 offset + PTRACE_HBP_PAD_SZ);
 590                 if (ret)
 591                         return ret;
 592                 offset += PTRACE_HBP_PAD_SZ;
 593                 idx++;
 594         }
 595
 596         return 0;
 597 }
 598 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 599
 600 static int gpr_get(struct task_struct *target,
 601                    const struct user_regset *regset,
 602                    unsigned int pos, unsigned int count,
 603                    void *kbuf, void __user *ubuf)
 604 {
 605         struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
 606         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 607 }
 608
 609 static int gpr_set(struct task_struct *target, const struct user_regset *regset,
 610                    unsigned int pos, unsigned int count,
 611                    const void *kbuf, const void __user *ubuf)
 612 {
 613         int ret;
 614         struct user_pt_regs newregs = task_pt_regs(target)->user_regs;
 615
 616         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
 617         if (ret)
 618                 return ret;
 619
 620         if (!valid_user_regs(&newregs, target))
 621                 return -EINVAL;
 622
 623         task_pt_regs(target)->user_regs = newregs;
 624         return 0;
 625 }
 626
 627 static int fpr_active(struct task_struct *target, const struct user_regset *regset)
 628 {
 629         if (!system_supports_fpsimd())
 630                 return -ENODEV;
 631         return regset->n;
 632 }
 633
 634 /*
 635  * TODO: update fp accessors for lazy context switching (sync/flush hwstate)
 636  */
 637 static int fpr_get(struct task_struct *target, const struct user_regset *regset,
 638                    unsigned int pos, unsigned int count,
 639                    void *kbuf, void __user *ubuf)
 640 {
 641         struct user_fpsimd_state *uregs;
 642         uregs = &target->thread.fpsimd_state.user_fpsimd;
 643
 644         if (!system_supports_fpsimd())
 645                 return -EINVAL;
 646
 647         if (target == current)
 648                 fpsimd_preserve_current_state();
 649
 650         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 651 }
 652
 653 static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 654                    unsigned int pos, unsigned int count,
 655                    const void *kbuf, const void __user *ubuf)
 656 {
 657         int ret;
 658         struct user_fpsimd_state newstate =
 659                 target->thread.fpsimd_state.user_fpsimd;
 660
 661         if (!system_supports_fpsimd())
 662                 return -EINVAL;
 663
 664         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1);
 665         if (ret)
 666                 return ret;
 667
 668         target->thread.fpsimd_state.user_fpsimd = newstate;
 669         fpsimd_flush_task_state(target);
 670         return ret;
 671 }
 672
 673 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 674                    unsigned int pos, unsigned int count,
 675                    void *kbuf, void __user *ubuf)
 676 {
 677         unsigned long *tls = &target->thread.tp_value;
 678
 679         if (target == current)
 680                 tls_preserve_current_state();
 681
 682         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
 683 }
 684
 685 static int tls_set(struct task_struct *target, const struct user_regset *regset,
 686                    unsigned int pos, unsigned int count,
 687                    const void *kbuf, const void __user *ubuf)
 688 {
 689         int ret;
 690         unsigned long tls = target->thread.tp_value;
 691
 692         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 693         if (ret)
 694                 return ret;
 695
 696         target->thread.tp_value = tls;
 697         return ret;
 698 }
 699
 700 static int system_call_get(struct task_struct *target,
 701                            const struct user_regset *regset,
 702                            unsigned int pos, unsigned int count,
 703                            void *kbuf, void __user *ubuf)
 704 {
 705         int syscallno = task_pt_regs(target)->syscallno;
 706
 707         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 708                                    &syscallno, 0, -1);
 709 }
 710
 711 static int system_call_set(struct task_struct *target,
 712                            const struct user_regset *regset,
 713                            unsigned int pos, unsigned int count,
 714                            const void *kbuf, const void __user *ubuf)
 715 {
 716         int syscallno = task_pt_regs(target)->syscallno;
 717         int ret;
 718
 719         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &syscallno, 0, -1);
 720         if (ret)
 721                 return ret;
 722
 723         task_pt_regs(target)->syscallno = syscallno;
 724         return ret;
 725 }
 726
 727 enum aarch64_regset {
 728         REGSET_GPR,
 729         REGSET_FPR,
 730         REGSET_TLS,
 731 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 732         REGSET_HW_BREAK,
 733         REGSET_HW_WATCH,
 734 #endif
 735         REGSET_SYSTEM_CALL,
 736 };
 737
 738 static const struct user_regset aarch64_regsets[] = {
 739         [REGSET_GPR] = {
 740                 .core_note_type = NT_PRSTATUS,
 741                 .n = sizeof(struct user_pt_regs) / sizeof(u64),
 742                 .size = sizeof(u64),
 743                 .align = sizeof(u64),
 744                 .get = gpr_get,
 745                 .set = gpr_set
 746         },
 747         [REGSET_FPR] = {
 748                 .core_note_type = NT_PRFPREG,
 749                 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
 750                 /*
 751                  * We pretend we have 32-bit registers because the fpsr and
 752                  * fpcr are 32-bits wide.
 753                  */
 754                 .size = sizeof(u32),
 755                 .align = sizeof(u32),
 756                 .active = fpr_active,
 757                 .get = fpr_get,
 758                 .set = fpr_set
 759         },
 760         [REGSET_TLS] = {
 761                 .core_note_type = NT_ARM_TLS,
 762                 .n = 1,
 763                 .size = sizeof(void *),
 764                 .align = sizeof(void *),
 765                 .get = tls_get,
 766                 .set = tls_set,
 767         },
 768 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 769         [REGSET_HW_BREAK] = {
 770                 .core_note_type = NT_ARM_HW_BREAK,
 771                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 772                 .size = sizeof(u32),
 773                 .align = sizeof(u32),
 774                 .get = hw_break_get,
 775                 .set = hw_break_set,
 776         },
 777         [REGSET_HW_WATCH] = {
 778                 .core_note_type = NT_ARM_HW_WATCH,
 779                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 780                 .size = sizeof(u32),
 781                 .align = sizeof(u32),
 782                 .get = hw_break_get,
 783                 .set = hw_break_set,
 784         },
 785 #endif
 786         [REGSET_SYSTEM_CALL] = {
 787                 .core_note_type = NT_ARM_SYSTEM_CALL,
 788                 .n = 1,
 789                 .size = sizeof(int),
 790                 .align = sizeof(int),
 791                 .get = system_call_get,
 792                 .set = system_call_set,
 793         },
 794 };
 795
 796 static const struct user_regset_view user_aarch64_view = {
 797         .name = "aarch64", .e_machine = EM_AARCH64,
 798         .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
 799 };
 800
 801 #ifdef CONFIG_COMPAT
 802 #include <linux/compat.h>
 803
 804 enum compat_regset {
 805         REGSET_COMPAT_GPR,
 806         REGSET_COMPAT_VFP,
 807 };
 808
 809 static int compat_gpr_get(struct task_struct *target,
 810                           const struct user_regset *regset,
 811                           unsigned int pos, unsigned int count,
 812                           void *kbuf, void __user *ubuf)
 813 {
 814         int ret = 0;
 815         unsigned int i, start, num_regs;
 816
 817         /* Calculate the number of AArch32 registers contained in count */
 818         num_regs = count / regset->size;
 819
 820         /* Convert pos into an register number */
 821         start = pos / regset->size;
 822
 823         if (start + num_regs > regset->n)
 824                 return -EIO;
 825
 826         for (i = 0; i < num_regs; ++i) {
 827                 unsigned int idx = start + i;
 828                 compat_ulong_t reg;
 829
 830                 switch (idx) {
 831                 case 15:
 832                         reg = task_pt_regs(target)->pc;
 833                         break;
 834                 case 16:
 835                         reg = task_pt_regs(target)->pstate;
 836                         reg = pstate_to_compat_psr(reg);
 837                         break;
 838                 case 17:
 839                         reg = task_pt_regs(target)->orig_x0;
 840                         break;
 841                 default:
 842                         reg = task_pt_regs(target)->regs[idx];
 843                 }
 844
 845                 if (kbuf) {
 846                         memcpy(kbuf, &reg, sizeof(reg));
 847                         kbuf += sizeof(reg);
 848                 } else {
 849                         ret = copy_to_user(ubuf, &reg, sizeof(reg));
 850                         if (ret) {
 851                                 ret = -EFAULT;
 852                                 break;
 853                         }
 854
 855                         ubuf += sizeof(reg);
 856                 }
 857         }
 858
 859         return ret;
 860 }
 861
 862 static int compat_gpr_set(struct task_struct *target,
 863                           const struct user_regset *regset,
 864                           unsigned int pos, unsigned int count,
 865                           const void *kbuf, const void __user *ubuf)
 866 {
 867         struct pt_regs newregs;
 868         int ret = 0;
 869         unsigned int i, start, num_regs;
 870
 871         /* Calculate the number of AArch32 registers contained in count */
 872         num_regs = count / regset->size;
 873
 874         /* Convert pos into an register number */
 875         start = pos / regset->size;
 876
 877         if (start + num_regs > regset->n)
 878                 return -EIO;
 879
 880         newregs = *task_pt_regs(target);
 881
 882         for (i = 0; i < num_regs; ++i) {
 883                 unsigned int idx = start + i;
 884                 compat_ulong_t reg;
 885
 886                 if (kbuf) {
 887                         memcpy(&reg, kbuf, sizeof(reg));
 888                         kbuf += sizeof(reg);
 889                 } else {
 890                         ret = copy_from_user(&reg, ubuf, sizeof(reg));
 891                         if (ret) {
 892                                 ret = -EFAULT;
 893                                 break;
 894                         }
 895
 896                         ubuf += sizeof(reg);
 897                 }
 898
 899                 switch (idx) {
 900                 case 15:
 901                         newregs.pc = reg;
 902                         break;
 903                 case 16:
 904                         reg = compat_psr_to_pstate(reg);
 905                         newregs.pstate = reg;
 906                         break;
 907                 case 17:
 908                         newregs.orig_x0 = reg;
 909                         break;
 910                 default:
 911                         newregs.regs[idx] = reg;
 912                 }
 913
 914         }
 915
 916         if (valid_user_regs(&newregs.user_regs, target))
 917                 *task_pt_regs(target) = newregs;
 918         else
 919                 ret = -EINVAL;
 920
 921         return ret;
 922 }
 923
 924 static int compat_vfp_get(struct task_struct *target,
 925                           const struct user_regset *regset,
 926                           unsigned int pos, unsigned int count,
 927                           void *kbuf, void __user *ubuf)
 928 {
 929         struct user_fpsimd_state *uregs;
 930         compat_ulong_t fpscr;
 931         int ret, vregs_end_pos;
 932
 933         if (!system_supports_fpsimd())
 934                 return -EINVAL;
 935
 936         uregs = &target->thread.fpsimd_state.user_fpsimd;
 937
 938         if (target == current)
 939                 fpsimd_preserve_current_state();
 940
 941         /*
 942          * The VFP registers are packed into the fpsimd_state, so they all sit
 943          * nicely together for us. We just need to create the fpscr separately.
 944          */
 945         vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t);
 946         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs,
 947                                   0, vregs_end_pos);
 948
 949         if (count && !ret) {
 950                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
 951                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
 952
 953                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &fpscr,
 954                                           vregs_end_pos, VFP_STATE_SIZE);
 955         }
 956
 957         return ret;
 958 }
 959
 960 static int compat_vfp_set(struct task_struct *target,
 961                           const struct user_regset *regset,
 962                           unsigned int pos, unsigned int count,
 963                           const void *kbuf, const void __user *ubuf)
 964 {
 965         struct user_fpsimd_state *uregs;
 966         compat_ulong_t fpscr;
 967         int ret, vregs_end_pos;
 968
 969         if (!system_supports_fpsimd())
 970                 return -EINVAL;
 971
 972         uregs = &target->thread.fpsimd_state.user_fpsimd;
 973
 974         vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t);
 975         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
 976                                  vregs_end_pos);
 977
 978         if (count && !ret) {
 979                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpscr,
 980                                          vregs_end_pos, VFP_STATE_SIZE);
 981                 if (!ret) {
 982                         uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
 983                         uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
 984                 }
 985         }
 986
 987         fpsimd_flush_task_state(target);
 988         return ret;
 989 }
 990
 991 static int compat_tls_get(struct task_struct *target,
 992                           const struct user_regset *regset, unsigned int pos,
 993                           unsigned int count, void *kbuf, void __user *ubuf)
 994 {
 995         compat_ulong_t tls = (compat_ulong_t)target->thread.tp_value;
 996         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 997 }
 998
 999 static int compat_tls_set(struct task_struct *target,
1000                           const struct user_regset *regset, unsigned int pos,
1001                           unsigned int count, const void *kbuf,
1002                           const void __user *ubuf)
1003 {
1004         int ret;
1005         compat_ulong_t tls = target->thread.tp_value;
1006
1007         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
1008         if (ret)
1009                 return ret;
1010
1011         target->thread.tp_value = tls;
1012         return ret;
1013 }
1014
1015 static const struct user_regset aarch32_regsets[] = {
1016         [REGSET_COMPAT_GPR] = {
1017                 .core_note_type = NT_PRSTATUS,
1018                 .n = COMPAT_ELF_NGREG,
1019                 .size = sizeof(compat_elf_greg_t),
1020                 .align = sizeof(compat_elf_greg_t),
1021                 .get = compat_gpr_get,
1022                 .set = compat_gpr_set
1023         },
1024         [REGSET_COMPAT_VFP] = {
1025                 .core_note_type = NT_ARM_VFP,
1026                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
1027                 .size = sizeof(compat_ulong_t),
1028                 .align = sizeof(compat_ulong_t),
1029                 .active = fpr_active,
1030                 .get = compat_vfp_get,
1031                 .set = compat_vfp_set
1032         },
1033 };
1034
1035 static const struct user_regset_view user_aarch32_view = {
1036         .name = "aarch32", .e_machine = EM_ARM,
1037         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
1038 };
1039
1040 static const struct user_regset aarch32_ptrace_regsets[] = {
1041         [REGSET_GPR] = {
1042                 .core_note_type = NT_PRSTATUS,
1043                 .n = COMPAT_ELF_NGREG,
1044                 .size = sizeof(compat_elf_greg_t),
1045                 .align = sizeof(compat_elf_greg_t),
1046                 .get = compat_gpr_get,
1047                 .set = compat_gpr_set
1048         },
1049         [REGSET_FPR] = {
1050                 .core_note_type = NT_ARM_VFP,
1051                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
1052                 .size = sizeof(compat_ulong_t),
1053                 .align = sizeof(compat_ulong_t),
1054                 .get = compat_vfp_get,
1055                 .set = compat_vfp_set
1056         },
1057         [REGSET_TLS] = {
1058                 .core_note_type = NT_ARM_TLS,
1059                 .n = 1,
1060                 .size = sizeof(compat_ulong_t),
1061                 .align = sizeof(compat_ulong_t),
1062                 .get = compat_tls_get,
1063                 .set = compat_tls_set,
1064         },
1065 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1066         [REGSET_HW_BREAK] = {
1067                 .core_note_type = NT_ARM_HW_BREAK,
1068                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1069                 .size = sizeof(u32),
1070                 .align = sizeof(u32),
1071                 .get = hw_break_get,
1072                 .set = hw_break_set,
1073         },
1074         [REGSET_HW_WATCH] = {
1075                 .core_note_type = NT_ARM_HW_WATCH,
1076                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1077                 .size = sizeof(u32),
1078                 .align = sizeof(u32),
1079                 .get = hw_break_get,
1080                 .set = hw_break_set,
1081         },
1082 #endif
1083         [REGSET_SYSTEM_CALL] = {
1084                 .core_note_type = NT_ARM_SYSTEM_CALL,
1085                 .n = 1,
1086                 .size = sizeof(int),
1087                 .align = sizeof(int),
1088                 .get = system_call_get,
1089                 .set = system_call_set,
1090         },
1091 };
1092
1093 static const struct user_regset_view user_aarch32_ptrace_view = {
1094         .name = "aarch32", .e_machine = EM_ARM,
1095         .regsets = aarch32_ptrace_regsets, .n = ARRAY_SIZE(aarch32_ptrace_regsets)
1096 };
1097
1098 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
1099                                    compat_ulong_t __user *ret)
1100 {
1101         compat_ulong_t tmp;
1102
1103         if (off & 3)
1104                 return -EIO;
1105
1106         if (off == COMPAT_PT_TEXT_ADDR)
1107                 tmp = tsk->mm->start_code;
1108         else if (off == COMPAT_PT_DATA_ADDR)
1109                 tmp = tsk->mm->start_data;
1110         else if (off == COMPAT_PT_TEXT_END_ADDR)
1111                 tmp = tsk->mm->end_code;
1112         else if (off < sizeof(compat_elf_gregset_t))
1113                 return copy_regset_to_user(tsk, &user_aarch32_view,
1114                                            REGSET_COMPAT_GPR, off,
1115                                            sizeof(compat_ulong_t), ret);
1116         else if (off >= COMPAT_USER_SZ)
1117                 return -EIO;
1118         else
1119                 tmp = 0;
1120
1121         return put_user(tmp, ret);
1122 }
1123
1124 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
1125                                     compat_ulong_t val)
1126 {
1127         int ret;
1128         mm_segment_t old_fs = get_fs();
1129
1130         if (off & 3 || off >= COMPAT_USER_SZ)
1131                 return -EIO;
1132
1133         if (off >= sizeof(compat_elf_gregset_t))
1134                 return 0;
1135
1136         set_fs(KERNEL_DS);
1137         ret = copy_regset_from_user(tsk, &user_aarch32_view,
1138                                     REGSET_COMPAT_GPR, off,
1139                                     sizeof(compat_ulong_t),
1140                                     &val);
1141         set_fs(old_fs);
1142
1143         return ret;
1144 }
1145
1146 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1147
1148 /*
1149  * Convert a virtual register number into an index for a thread_info
1150  * breakpoint array. Breakpoints are identified using positive numbers
1151  * whilst watchpoints are negative. The registers are laid out as pairs
1152  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
1153  * Register 0 is reserved for describing resource information.
1154  */
1155 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
1156 {
1157         return (abs(num) - 1) >> 1;
1158 }
1159
1160 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
1161 {
1162         u8 num_brps, num_wrps, debug_arch, wp_len;
1163         u32 reg = 0;
1164
1165         num_brps        = hw_breakpoint_slots(TYPE_INST);
1166         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
1167
1168         debug_arch      = debug_monitors_arch();
1169         wp_len          = 8;
1170         reg             |= debug_arch;
1171         reg             <<= 8;
1172         reg             |= wp_len;
1173         reg             <<= 8;
1174         reg             |= num_wrps;
1175         reg             <<= 8;
1176         reg             |= num_brps;
1177
1178         *kdata = reg;
1179         return 0;
1180 }
1181
1182 static int compat_ptrace_hbp_get(unsigned int note_type,
1183                                  struct task_struct *tsk,
1184                                  compat_long_t num,
1185                                  u32 *kdata)
1186 {
1187         u64 addr = 0;
1188         u32 ctrl = 0;
1189
1190         int err, idx = compat_ptrace_hbp_num_to_idx(num);;
1191
1192         if (num & 1) {
1193                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
1194                 *kdata = (u32)addr;
1195         } else {
1196                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
1197                 *kdata = ctrl;
1198         }
1199
1200         return err;
1201 }
1202
1203 static int compat_ptrace_hbp_set(unsigned int note_type,
1204                                  struct task_struct *tsk,
1205                                  compat_long_t num,
1206                                  u32 *kdata)
1207 {
1208         u64 addr;
1209         u32 ctrl;
1210
1211         int err, idx = compat_ptrace_hbp_num_to_idx(num);
1212
1213         if (num & 1) {
1214                 addr = *kdata;
1215                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
1216         } else {
1217                 ctrl = *kdata;
1218                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
1219         }
1220
1221         return err;
1222 }
1223
1224 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
1225                                     compat_ulong_t __user *data)
1226 {
1227         int ret;
1228         u32 kdata;
1229
1230         /* Watchpoint */
1231         if (num < 0) {
1232                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
1233         /* Resource info */
1234         } else if (num == 0) {
1235                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
1236         /* Breakpoint */
1237         } else {
1238                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
1239         }
1240
1241         if (!ret)
1242                 ret = put_user(kdata, data);
1243
1244         return ret;
1245 }
1246
1247 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
1248                                     compat_ulong_t __user *data)
1249 {
1250         int ret;
1251         u32 kdata = 0;
1252
1253         if (num == 0)
1254                 return 0;
1255
1256         ret = get_user(kdata, data);
1257         if (ret)
1258                 return ret;
1259
1260         if (num < 0)
1261                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
1262         else
1263                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
1264
1265         return ret;
1266 }
1267 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
1268
1269 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1270                         compat_ulong_t caddr, compat_ulong_t cdata)
1271 {
1272         unsigned long addr = caddr;
1273         unsigned long data = cdata;
1274         void __user *datap = compat_ptr(data);
1275         int ret;
1276
1277         switch (request) {
1278                 case PTRACE_PEEKUSR:
1279                         ret = compat_ptrace_read_user(child, addr, datap);
1280                         break;
1281
1282                 case PTRACE_POKEUSR:
1283                         ret = compat_ptrace_write_user(child, addr, data);
1284                         break;
1285
1286                 case COMPAT_PTRACE_GETREGS:
1287                         ret = copy_regset_to_user(child,
1288                                                   &user_aarch32_view,
1289                                                   REGSET_COMPAT_GPR,
1290                                                   0, sizeof(compat_elf_gregset_t),
1291                                                   datap);
1292                         break;
1293
1294                 case COMPAT_PTRACE_SETREGS:
1295                         ret = copy_regset_from_user(child,
1296                                                     &user_aarch32_view,
1297                                                     REGSET_COMPAT_GPR,
1298                                                     0, sizeof(compat_elf_gregset_t),
1299                                                     datap);
1300                         break;
1301
1302                 case COMPAT_PTRACE_GET_THREAD_AREA:
1303                         ret = put_user((compat_ulong_t)child->thread.tp_value,
1304                                        (compat_ulong_t __user *)datap);
1305                         break;
1306
1307                 case COMPAT_PTRACE_SET_SYSCALL:
1308                         task_pt_regs(child)->syscallno = data;
1309                         ret = 0;
1310                         break;
1311
1312                 case COMPAT_PTRACE_GETVFPREGS:
1313                         ret = copy_regset_to_user(child,
1314                                                   &user_aarch32_view,
1315                                                   REGSET_COMPAT_VFP,
1316                                                   0, VFP_STATE_SIZE,
1317                                                   datap);
1318                         break;
1319
1320                 case COMPAT_PTRACE_SETVFPREGS:
1321                         ret = copy_regset_from_user(child,
1322                                                     &user_aarch32_view,
1323                                                     REGSET_COMPAT_VFP,
1324                                                     0, VFP_STATE_SIZE,
1325                                                     datap);
1326                         break;
1327
1328 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1329                 case COMPAT_PTRACE_GETHBPREGS:
1330                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1331                         break;
1332
1333                 case COMPAT_PTRACE_SETHBPREGS:
1334                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1335                         break;
1336 #endif
1337
1338                 default:
1339                         ret = compat_ptrace_request(child, request, addr,
1340                                                     data);
1341                         break;
1342         }
1343
1344         return ret;
1345 }
1346 #endif /* CONFIG_COMPAT */
1347
1348 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1349 {
1350 #ifdef CONFIG_COMPAT
1351         /*
1352          * Core dumping of 32-bit tasks or compat ptrace requests must use the
1353          * user_aarch32_view compatible with arm32. Native ptrace requests on
1354          * 32-bit children use an extended user_aarch32_ptrace_view to allow
1355          * access to the TLS register.
1356          */
1357         if (is_compat_task())
1358                 return &user_aarch32_view;
1359         else if (is_compat_thread(task_thread_info(task)))
1360                 return &user_aarch32_ptrace_view;
1361 #endif
1362         return &user_aarch64_view;
1363 }
1364
1365 long arch_ptrace(struct task_struct *child, long request,
1366                  unsigned long addr, unsigned long data)
1367 {
1368         return ptrace_request(child, request, addr, data);
1369 }
1370
1371 enum ptrace_syscall_dir {
1372         PTRACE_SYSCALL_ENTER = 0,
1373         PTRACE_SYSCALL_EXIT,
1374 };
1375
1376 static void tracehook_report_syscall(struct pt_regs *regs,
1377                                      enum ptrace_syscall_dir dir)
1378 {
1379         int regno;
1380         unsigned long saved_reg;
1381
1382         /*
1383          * A scratch register (ip(r12) on AArch32, x7 on AArch64) is
1384          * used to denote syscall entry/exit:
1385          */
1386         regno = (is_compat_task() ? 12 : 7);
1387         saved_reg = regs->regs[regno];
1388         regs->regs[regno] = dir;
1389
1390         if (dir == PTRACE_SYSCALL_EXIT)
1391                 tracehook_report_syscall_exit(regs, 0);
1392         else if (tracehook_report_syscall_entry(regs))
1393                 forget_syscall(regs);
1394
1395         regs->regs[regno] = saved_reg;
1396 }
1397
1398 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
1399 {
1400         if (test_thread_flag(TIF_SYSCALL_TRACE))
1401                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1402
1403         /* Do the secure computing after ptrace; failures should be fast. */
1404         if (secure_computing(NULL) == -1)
1405                 return -1;
1406
1407         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1408                 trace_sys_enter(regs, regs->syscallno);
1409
1410         audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1],
1411                             regs->regs[2], regs->regs[3]);
1412
1413         return regs->syscallno;
1414 }
1415
1416 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
1417 {
1418         audit_syscall_exit(regs);
1419
1420         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1421                 trace_sys_exit(regs, regs_return_value(regs));
1422
1423         if (test_thread_flag(TIF_SYSCALL_TRACE))
1424                 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1425 }
1426
1427 /*
1428  * SPSR_ELx bits which are always architecturally RES0 per ARM DDI 0487D.a.
1429  * We permit userspace to set SSBS (AArch64 bit 12, AArch32 bit 23) which is
1430  * not described in ARM DDI 0487D.a.
1431  * We treat PAN and UAO as RES0 bits, as they are meaningless at EL0, and may
1432  * be allocated an EL0 meaning in future.
1433  * Userspace cannot use these until they have an architectural meaning.
1434  * Note that this follows the SPSR_ELx format, not the AArch32 PSR format.
1435  * We also reserve IL for the kernel; SS is handled dynamically.
1436  */
1437 #define SPSR_EL1_AARCH64_RES0_BITS \
1438         (GENMASK_ULL(63, 32) | GENMASK_ULL(27, 25) | GENMASK_ULL(23, 22) | \
1439          GENMASK_ULL(20, 13) | GENMASK_ULL(11, 10) | GENMASK_ULL(5, 5))
1440 #define SPSR_EL1_AARCH32_RES0_BITS \
1441         (GENMASK_ULL(63, 32) | GENMASK_ULL(22, 22) | GENMASK_ULL(20, 20))
1442
1443 static int valid_compat_regs(struct user_pt_regs *regs)
1444 {
1445         regs->pstate &= ~SPSR_EL1_AARCH32_RES0_BITS;
1446
1447         if (!system_supports_mixed_endian_el0()) {
1448                 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
1449                         regs->pstate |= COMPAT_PSR_E_BIT;
1450                 else
1451                         regs->pstate &= ~COMPAT_PSR_E_BIT;
1452         }
1453
1454         if (user_mode(regs) && (regs->pstate & PSR_MODE32_BIT) &&
1455             (regs->pstate & COMPAT_PSR_A_BIT) == 0 &&
1456             (regs->pstate & COMPAT_PSR_I_BIT) == 0 &&
1457             (regs->pstate & COMPAT_PSR_F_BIT) == 0) {
1458                 return 1;
1459         }
1460
1461         /*
1462          * Force PSR to a valid 32-bit EL0t, preserving the same bits as
1463          * arch/arm.
1464          */
1465         regs->pstate &= COMPAT_PSR_N_BIT | COMPAT_PSR_Z_BIT |
1466                         COMPAT_PSR_C_BIT | COMPAT_PSR_V_BIT |
1467                         COMPAT_PSR_Q_BIT | COMPAT_PSR_IT_MASK |
1468                         COMPAT_PSR_GE_MASK | COMPAT_PSR_E_BIT |
1469                         COMPAT_PSR_T_BIT;
1470         regs->pstate |= PSR_MODE32_BIT;
1471
1472         return 0;
1473 }
1474
1475 static int valid_native_regs(struct user_pt_regs *regs)
1476 {
1477         regs->pstate &= ~SPSR_EL1_AARCH64_RES0_BITS;
1478
1479         if (user_mode(regs) && !(regs->pstate & PSR_MODE32_BIT) &&
1480             (regs->pstate & PSR_D_BIT) == 0 &&
1481             (regs->pstate & PSR_A_BIT) == 0 &&
1482             (regs->pstate & PSR_I_BIT) == 0 &&
1483             (regs->pstate & PSR_F_BIT) == 0) {
1484                 return 1;
1485         }
1486
1487         /* Force PSR to a valid 64-bit EL0t */
1488         regs->pstate &= PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT;
1489
1490         return 0;
1491 }
1492
1493 /*
1494  * Are the current registers suitable for user mode? (used to maintain
1495  * security in signal handlers)
1496  */
1497 int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task)
1498 {
1499         /* https://lore.kernel.org/lkml/20191118131525.GA4180@willie-the-truck */
1500         user_regs_reset_single_step(regs, task);
1501
1502         if (is_compat_thread(task_thread_info(task)))
1503                 return valid_compat_regs(regs);
1504         else
1505                 return valid_native_regs(regs);
1506 }