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/smp.h>
  29 #include <linux/ptrace.h>
  30 #include <linux/user.h>
  31 #include <linux/seccomp.h>
  32 #include <linux/security.h>
  33 #include <linux/init.h>
  34 #include <linux/signal.h>
  35 #include <linux/string.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/cpufeature.h>
  45 #include <asm/debug-monitors.h>
  46 #include <asm/pgtable.h>
  47 #include <asm/stacktrace.h>
  48 #include <asm/syscall.h>
  49 #include <asm/traps.h>
  50 #include <asm/system_misc.h>
  51
  52 #define CREATE_TRACE_POINTS
  53 #include <trace/events/syscalls.h>
  54
  55 struct pt_regs_offset {
  56         const char *name;
  57         int offset;
  58 };
  59
  60 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  61 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  62 #define GPR_OFFSET_NAME(r) \
  63         {.name = "x" #r, .offset = offsetof(struct pt_regs, regs[r])}
  64
  65 static const struct pt_regs_offset regoffset_table[] = {
  66         GPR_OFFSET_NAME(0),
  67         GPR_OFFSET_NAME(1),
  68         GPR_OFFSET_NAME(2),
  69         GPR_OFFSET_NAME(3),
  70         GPR_OFFSET_NAME(4),
  71         GPR_OFFSET_NAME(5),
  72         GPR_OFFSET_NAME(6),
  73         GPR_OFFSET_NAME(7),
  74         GPR_OFFSET_NAME(8),
  75         GPR_OFFSET_NAME(9),
  76         GPR_OFFSET_NAME(10),
  77         GPR_OFFSET_NAME(11),
  78         GPR_OFFSET_NAME(12),
  79         GPR_OFFSET_NAME(13),
  80         GPR_OFFSET_NAME(14),
  81         GPR_OFFSET_NAME(15),
  82         GPR_OFFSET_NAME(16),
  83         GPR_OFFSET_NAME(17),
  84         GPR_OFFSET_NAME(18),
  85         GPR_OFFSET_NAME(19),
  86         GPR_OFFSET_NAME(20),
  87         GPR_OFFSET_NAME(21),
  88         GPR_OFFSET_NAME(22),
  89         GPR_OFFSET_NAME(23),
  90         GPR_OFFSET_NAME(24),
  91         GPR_OFFSET_NAME(25),
  92         GPR_OFFSET_NAME(26),
  93         GPR_OFFSET_NAME(27),
  94         GPR_OFFSET_NAME(28),
  95         GPR_OFFSET_NAME(29),
  96         GPR_OFFSET_NAME(30),
  97         {.name = "lr", .offset = offsetof(struct pt_regs, regs[30])},
  98         REG_OFFSET_NAME(sp),
  99         REG_OFFSET_NAME(pc),
 100         REG_OFFSET_NAME(pstate),
 101         REG_OFFSET_END,
 102 };
 103
 104 /**
 105  * regs_query_register_offset() - query register offset from its name
 106  * @name:       the name of a register
 107  *
 108  * regs_query_register_offset() returns the offset of a register in struct
 109  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 110  */
 111 int regs_query_register_offset(const char *name)
 112 {
 113         const struct pt_regs_offset *roff;
 114
 115         for (roff = regoffset_table; roff->name != NULL; roff++)
 116                 if (!strcmp(roff->name, name))
 117                         return roff->offset;
 118         return -EINVAL;
 119 }
 120
 121 /**
 122  * regs_within_kernel_stack() - check the address in the stack
 123  * @regs:      pt_regs which contains kernel stack pointer.
 124  * @addr:      address which is checked.
 125  *
 126  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 127  * If @addr is within the kernel stack, it returns true. If not, returns false.
 128  */
 129 static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 130 {
 131         return ((addr & ~(THREAD_SIZE - 1))  ==
 132                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))) ||
 133                 on_irq_stack(addr);
 134 }
 135
 136 /**
 137  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 138  * @regs:       pt_regs which contains kernel stack pointer.
 139  * @n:          stack entry number.
 140  *
 141  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 142  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 143  * this returns 0.
 144  */
 145 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 146 {
 147         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 148
 149         addr += n;
 150         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 151                 return *addr;
 152         else
 153                 return 0;
 154 }
 155
 156 /*
 157  * TODO: does not yet catch signals sent when the child dies.
 158  * in exit.c or in signal.c.
 159  */
 160
 161 /*
 162  * Called by kernel/ptrace.c when detaching..
 163  */
 164 void ptrace_disable(struct task_struct *child)
 165 {
 166         /*
 167          * This would be better off in core code, but PTRACE_DETACH has
 168          * grown its fair share of arch-specific worts and changing it
 169          * is likely to cause regressions on obscure architectures.
 170          */
 171         user_disable_single_step(child);
 172 }
 173
 174 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 175 /*
 176  * Handle hitting a HW-breakpoint.
 177  */
 178 static void ptrace_hbptriggered(struct perf_event *bp,
 179                                 struct perf_sample_data *data,
 180                                 struct pt_regs *regs)
 181 {
 182         struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
 183         siginfo_t info = {
 184                 .si_signo       = SIGTRAP,
 185                 .si_errno       = 0,
 186                 .si_code        = TRAP_HWBKPT,
 187                 .si_addr        = (void __user *)(bkpt->trigger),
 188         };
 189
 190 #ifdef CONFIG_COMPAT
 191         int i;
 192
 193         if (!is_compat_task())
 194                 goto send_sig;
 195
 196         for (i = 0; i < ARM_MAX_BRP; ++i) {
 197                 if (current->thread.debug.hbp_break[i] == bp) {
 198                         info.si_errno = (i << 1) + 1;
 199                         break;
 200                 }
 201         }
 202
 203         for (i = 0; i < ARM_MAX_WRP; ++i) {
 204                 if (current->thread.debug.hbp_watch[i] == bp) {
 205                         info.si_errno = -((i << 1) + 1);
 206                         break;
 207                 }
 208         }
 209
 210 send_sig:
 211 #endif
 212         force_sig_info(SIGTRAP, &info, current);
 213 }
 214
 215 /*
 216  * Unregister breakpoints from this task and reset the pointers in
 217  * the thread_struct.
 218  */
 219 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 220 {
 221         int i;
 222         struct thread_struct *t = &tsk->thread;
 223
 224         for (i = 0; i < ARM_MAX_BRP; i++) {
 225                 if (t->debug.hbp_break[i]) {
 226                         unregister_hw_breakpoint(t->debug.hbp_break[i]);
 227                         t->debug.hbp_break[i] = NULL;
 228                 }
 229         }
 230
 231         for (i = 0; i < ARM_MAX_WRP; i++) {
 232                 if (t->debug.hbp_watch[i]) {
 233                         unregister_hw_breakpoint(t->debug.hbp_watch[i]);
 234                         t->debug.hbp_watch[i] = NULL;
 235                 }
 236         }
 237 }
 238
 239 void ptrace_hw_copy_thread(struct task_struct *tsk)
 240 {
 241         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 242 }
 243
 244 static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
 245                                                struct task_struct *tsk,
 246                                                unsigned long idx)
 247 {
 248         struct perf_event *bp = ERR_PTR(-EINVAL);
 249
 250         switch (note_type) {
 251         case NT_ARM_HW_BREAK:
 252                 if (idx < ARM_MAX_BRP)
 253                         bp = tsk->thread.debug.hbp_break[idx];
 254                 break;
 255         case NT_ARM_HW_WATCH:
 256                 if (idx < ARM_MAX_WRP)
 257                         bp = tsk->thread.debug.hbp_watch[idx];
 258                 break;
 259         }
 260
 261         return bp;
 262 }
 263
 264 static int ptrace_hbp_set_event(unsigned int note_type,
 265                                 struct task_struct *tsk,
 266                                 unsigned long idx,
 267                                 struct perf_event *bp)
 268 {
 269         int err = -EINVAL;
 270
 271         switch (note_type) {
 272         case NT_ARM_HW_BREAK:
 273                 if (idx < ARM_MAX_BRP) {
 274                         tsk->thread.debug.hbp_break[idx] = bp;
 275                         err = 0;
 276                 }
 277                 break;
 278         case NT_ARM_HW_WATCH:
 279                 if (idx < ARM_MAX_WRP) {
 280                         tsk->thread.debug.hbp_watch[idx] = bp;
 281                         err = 0;
 282                 }
 283                 break;
 284         }
 285
 286         return err;
 287 }
 288
 289 static struct perf_event *ptrace_hbp_create(unsigned int note_type,
 290                                             struct task_struct *tsk,
 291                                             unsigned long idx)
 292 {
 293         struct perf_event *bp;
 294         struct perf_event_attr attr;
 295         int err, type;
 296
 297         switch (note_type) {
 298         case NT_ARM_HW_BREAK:
 299                 type = HW_BREAKPOINT_X;
 300                 break;
 301         case NT_ARM_HW_WATCH:
 302                 type = HW_BREAKPOINT_RW;
 303                 break;
 304         default:
 305                 return ERR_PTR(-EINVAL);
 306         }
 307
 308         ptrace_breakpoint_init(&attr);
 309
 310         /*
 311          * Initialise fields to sane defaults
 312          * (i.e. values that will pass validation).
 313          */
 314         attr.bp_addr    = 0;
 315         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 316         attr.bp_type    = type;
 317         attr.disabled   = 1;
 318
 319         bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk);
 320         if (IS_ERR(bp))
 321                 return bp;
 322
 323         err = ptrace_hbp_set_event(note_type, tsk, idx, bp);
 324         if (err)
 325                 return ERR_PTR(err);
 326
 327         return bp;
 328 }
 329
 330 static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
 331                                      struct arch_hw_breakpoint_ctrl ctrl,
 332                                      struct perf_event_attr *attr)
 333 {
 334         int err, len, type, offset, disabled = !ctrl.enabled;
 335
 336         attr->disabled = disabled;
 337         if (disabled)
 338                 return 0;
 339
 340         err = arch_bp_generic_fields(ctrl, &len, &type, &offset);
 341         if (err)
 342                 return err;
 343
 344         switch (note_type) {
 345         case NT_ARM_HW_BREAK:
 346                 if ((type & HW_BREAKPOINT_X) != type)
 347                         return -EINVAL;
 348                 break;
 349         case NT_ARM_HW_WATCH:
 350                 if ((type & HW_BREAKPOINT_RW) != type)
 351                         return -EINVAL;
 352                 break;
 353         default:
 354                 return -EINVAL;
 355         }
 356
 357         attr->bp_len    = len;
 358         attr->bp_type   = type;
 359         attr->bp_addr   += offset;
 360
 361         return 0;
 362 }
 363
 364 static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info)
 365 {
 366         u8 num;
 367         u32 reg = 0;
 368
 369         switch (note_type) {
 370         case NT_ARM_HW_BREAK:
 371                 num = hw_breakpoint_slots(TYPE_INST);
 372                 break;
 373         case NT_ARM_HW_WATCH:
 374                 num = hw_breakpoint_slots(TYPE_DATA);
 375                 break;
 376         default:
 377                 return -EINVAL;
 378         }
 379
 380         reg |= debug_monitors_arch();
 381         reg <<= 8;
 382         reg |= num;
 383
 384         *info = reg;
 385         return 0;
 386 }
 387
 388 static int ptrace_hbp_get_ctrl(unsigned int note_type,
 389                                struct task_struct *tsk,
 390                                unsigned long idx,
 391                                u32 *ctrl)
 392 {
 393         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 394
 395         if (IS_ERR(bp))
 396                 return PTR_ERR(bp);
 397
 398         *ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0;
 399         return 0;
 400 }
 401
 402 static int ptrace_hbp_get_addr(unsigned int note_type,
 403                                struct task_struct *tsk,
 404                                unsigned long idx,
 405                                u64 *addr)
 406 {
 407         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 408
 409         if (IS_ERR(bp))
 410                 return PTR_ERR(bp);
 411
 412         *addr = bp ? counter_arch_bp(bp)->address : 0;
 413         return 0;
 414 }
 415
 416 static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type,
 417                                                         struct task_struct *tsk,
 418                                                         unsigned long idx)
 419 {
 420         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 421
 422         if (!bp)
 423                 bp = ptrace_hbp_create(note_type, tsk, idx);
 424
 425         return bp;
 426 }
 427
 428 static int ptrace_hbp_set_ctrl(unsigned int note_type,
 429                                struct task_struct *tsk,
 430                                unsigned long idx,
 431                                u32 uctrl)
 432 {
 433         int err;
 434         struct perf_event *bp;
 435         struct perf_event_attr attr;
 436         struct arch_hw_breakpoint_ctrl ctrl;
 437
 438         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 439         if (IS_ERR(bp)) {
 440                 err = PTR_ERR(bp);
 441                 return err;
 442         }
 443
 444         attr = bp->attr;
 445         decode_ctrl_reg(uctrl, &ctrl);
 446         err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
 447         if (err)
 448                 return err;
 449
 450         return modify_user_hw_breakpoint(bp, &attr);
 451 }
 452
 453 static int ptrace_hbp_set_addr(unsigned int note_type,
 454                                struct task_struct *tsk,
 455                                unsigned long idx,
 456                                u64 addr)
 457 {
 458         int err;
 459         struct perf_event *bp;
 460         struct perf_event_attr attr;
 461
 462         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 463         if (IS_ERR(bp)) {
 464                 err = PTR_ERR(bp);
 465                 return err;
 466         }
 467
 468         attr = bp->attr;
 469         attr.bp_addr = addr;
 470         err = modify_user_hw_breakpoint(bp, &attr);
 471         return err;
 472 }
 473
 474 #define PTRACE_HBP_ADDR_SZ      sizeof(u64)
 475 #define PTRACE_HBP_CTRL_SZ      sizeof(u32)
 476 #define PTRACE_HBP_PAD_SZ       sizeof(u32)
 477
 478 static int hw_break_get(struct task_struct *target,
 479                         const struct user_regset *regset,
 480                         unsigned int pos, unsigned int count,
 481                         void *kbuf, void __user *ubuf)
 482 {
 483         unsigned int note_type = regset->core_note_type;
 484         int ret, idx = 0, offset, limit;
 485         u32 info, ctrl;
 486         u64 addr;
 487
 488         /* Resource info */
 489         ret = ptrace_hbp_get_resource_info(note_type, &info);
 490         if (ret)
 491                 return ret;
 492
 493         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0,
 494                                   sizeof(info));
 495         if (ret)
 496                 return ret;
 497
 498         /* Pad */
 499         offset = offsetof(struct user_hwdebug_state, pad);
 500         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, offset,
 501                                        offset + PTRACE_HBP_PAD_SZ);
 502         if (ret)
 503                 return ret;
 504
 505         /* (address, ctrl) registers */
 506         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 507         limit = regset->n * regset->size;
 508         while (count && offset < limit) {
 509                 ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
 510                 if (ret)
 511                         return ret;
 512                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr,
 513                                           offset, offset + PTRACE_HBP_ADDR_SZ);
 514                 if (ret)
 515                         return ret;
 516                 offset += PTRACE_HBP_ADDR_SZ;
 517
 518                 ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
 519                 if (ret)
 520                         return ret;
 521                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl,
 522                                           offset, offset + PTRACE_HBP_CTRL_SZ);
 523                 if (ret)
 524                         return ret;
 525                 offset += PTRACE_HBP_CTRL_SZ;
 526
 527                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 528                                                offset,
 529                                                offset + PTRACE_HBP_PAD_SZ);
 530                 if (ret)
 531                         return ret;
 532                 offset += PTRACE_HBP_PAD_SZ;
 533                 idx++;
 534         }
 535
 536         return 0;
 537 }
 538
 539 static int hw_break_set(struct task_struct *target,
 540                         const struct user_regset *regset,
 541                         unsigned int pos, unsigned int count,
 542                         const void *kbuf, const void __user *ubuf)
 543 {
 544         unsigned int note_type = regset->core_note_type;
 545         int ret, idx = 0, offset, limit;
 546         u32 ctrl;
 547         u64 addr;
 548
 549         /* Resource info and pad */
 550         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 551         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset);
 552         if (ret)
 553                 return ret;
 554
 555         /* (address, ctrl) registers */
 556         limit = regset->n * regset->size;
 557         while (count && offset < limit) {
 558                 if (count < PTRACE_HBP_ADDR_SZ)
 559                         return -EINVAL;
 560                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
 561                                          offset, offset + PTRACE_HBP_ADDR_SZ);
 562                 if (ret)
 563                         return ret;
 564                 ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
 565                 if (ret)
 566                         return ret;
 567                 offset += PTRACE_HBP_ADDR_SZ;
 568
 569                 if (!count)
 570                         break;
 571                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
 572                                          offset, offset + PTRACE_HBP_CTRL_SZ);
 573                 if (ret)
 574                         return ret;
 575                 ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
 576                 if (ret)
 577                         return ret;
 578                 offset += PTRACE_HBP_CTRL_SZ;
 579
 580                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 581                                                 offset,
 582                                                 offset + PTRACE_HBP_PAD_SZ);
 583                 if (ret)
 584                         return ret;
 585                 offset += PTRACE_HBP_PAD_SZ;
 586                 idx++;
 587         }
 588
 589         return 0;
 590 }
 591 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 592
 593 static int gpr_get(struct task_struct *target,
 594                    const struct user_regset *regset,
 595                    unsigned int pos, unsigned int count,
 596                    void *kbuf, void __user *ubuf)
 597 {
 598         struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
 599         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 600 }
 601
 602 static int gpr_set(struct task_struct *target, const struct user_regset *regset,
 603                    unsigned int pos, unsigned int count,
 604                    const void *kbuf, const void __user *ubuf)
 605 {
 606         int ret;
 607         struct user_pt_regs newregs = task_pt_regs(target)->user_regs;
 608
 609         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
 610         if (ret)
 611                 return ret;
 612
 613         if (!valid_user_regs(&newregs, target))
 614                 return -EINVAL;
 615
 616         task_pt_regs(target)->user_regs = newregs;
 617         return 0;
 618 }
 619
 620 /*
 621  * TODO: update fp accessors for lazy context switching (sync/flush hwstate)
 622  */
 623 static int __fpr_get(struct task_struct *target,
 624                      const struct user_regset *regset,
 625                      unsigned int pos, unsigned int count,
 626                      void *kbuf, void __user *ubuf, unsigned int start_pos)
 627 {
 628         struct user_fpsimd_state *uregs;
 629
 630         sve_sync_to_fpsimd(target);
 631
 632         uregs = &target->thread.fpsimd_state.user_fpsimd;
 633
 634         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs,
 635                                    start_pos, start_pos + sizeof(*uregs));
 636 }
 637
 638 static int fpr_get(struct task_struct *target, const struct user_regset *regset,
 639                    unsigned int pos, unsigned int count,
 640                    void *kbuf, void __user *ubuf)
 641 {
 642         if (target == current)
 643                 fpsimd_preserve_current_state();
 644
 645         return __fpr_get(target, regset, pos, count, kbuf, ubuf, 0);
 646 }
 647
 648 static int __fpr_set(struct task_struct *target,
 649                      const struct user_regset *regset,
 650                      unsigned int pos, unsigned int count,
 651                      const void *kbuf, const void __user *ubuf,
 652                      unsigned int start_pos)
 653 {
 654         int ret;
 655         struct user_fpsimd_state newstate;
 656
 657         /*
 658          * Ensure target->thread.fpsimd_state is up to date, so that a
 659          * short copyin can't resurrect stale data.
 660          */
 661         sve_sync_to_fpsimd(target);
 662
 663         newstate = target->thread.fpsimd_state.user_fpsimd;
 664
 665         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate,
 666                                  start_pos, start_pos + sizeof(newstate));
 667         if (ret)
 668                 return ret;
 669
 670         target->thread.fpsimd_state.user_fpsimd = newstate;
 671
 672         return ret;
 673 }
 674
 675 static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 676                    unsigned int pos, unsigned int count,
 677                    const void *kbuf, const void __user *ubuf)
 678 {
 679         int ret;
 680
 681         ret = __fpr_set(target, regset, pos, count, kbuf, ubuf, 0);
 682         if (ret)
 683                 return ret;
 684
 685         sve_sync_from_fpsimd_zeropad(target);
 686         fpsimd_flush_task_state(target);
 687
 688         return ret;
 689 }
 690
 691 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 692                    unsigned int pos, unsigned int count,
 693                    void *kbuf, void __user *ubuf)
 694 {
 695         unsigned long *tls = &target->thread.tp_value;
 696
 697         if (target == current)
 698                 tls_preserve_current_state();
 699
 700         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
 701 }
 702
 703 static int tls_set(struct task_struct *target, const struct user_regset *regset,
 704                    unsigned int pos, unsigned int count,
 705                    const void *kbuf, const void __user *ubuf)
 706 {
 707         int ret;
 708         unsigned long tls = target->thread.tp_value;
 709
 710         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 711         if (ret)
 712                 return ret;
 713
 714         target->thread.tp_value = tls;
 715         return ret;
 716 }
 717
 718 static int system_call_get(struct task_struct *target,
 719                            const struct user_regset *regset,
 720                            unsigned int pos, unsigned int count,
 721                            void *kbuf, void __user *ubuf)
 722 {
 723         int syscallno = task_pt_regs(target)->syscallno;
 724
 725         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 726                                    &syscallno, 0, -1);
 727 }
 728
 729 static int system_call_set(struct task_struct *target,
 730                            const struct user_regset *regset,
 731                            unsigned int pos, unsigned int count,
 732                            const void *kbuf, const void __user *ubuf)
 733 {
 734         int syscallno = task_pt_regs(target)->syscallno;
 735         int ret;
 736
 737         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &syscallno, 0, -1);
 738         if (ret)
 739                 return ret;
 740
 741         task_pt_regs(target)->syscallno = syscallno;
 742         return ret;
 743 }
 744
 745 #ifdef CONFIG_ARM64_SVE
 746
 747 static void sve_init_header_from_task(struct user_sve_header *header,
 748                                       struct task_struct *target)
 749 {
 750         unsigned int vq;
 751
 752         memset(header, 0, sizeof(*header));
 753
 754         header->flags = test_tsk_thread_flag(target, TIF_SVE) ?
 755                 SVE_PT_REGS_SVE : SVE_PT_REGS_FPSIMD;
 756         if (test_tsk_thread_flag(target, TIF_SVE_VL_INHERIT))
 757                 header->flags |= SVE_PT_VL_INHERIT;
 758
 759         header->vl = target->thread.sve_vl;
 760         vq = sve_vq_from_vl(header->vl);
 761
 762         header->max_vl = sve_max_vl;
 763         if (WARN_ON(!sve_vl_valid(sve_max_vl)))
 764                 header->max_vl = header->vl;
 765
 766         header->size = SVE_PT_SIZE(vq, header->flags);
 767         header->max_size = SVE_PT_SIZE(sve_vq_from_vl(header->max_vl),
 768                                       SVE_PT_REGS_SVE);
 769 }
 770
 771 static unsigned int sve_size_from_header(struct user_sve_header const *header)
 772 {
 773         return ALIGN(header->size, SVE_VQ_BYTES);
 774 }
 775
 776 static unsigned int sve_get_size(struct task_struct *target,
 777                                  const struct user_regset *regset)
 778 {
 779         struct user_sve_header header;
 780
 781         if (!system_supports_sve())
 782                 return 0;
 783
 784         sve_init_header_from_task(&header, target);
 785         return sve_size_from_header(&header);
 786 }
 787
 788 static int sve_get(struct task_struct *target,
 789                    const struct user_regset *regset,
 790                    unsigned int pos, unsigned int count,
 791                    void *kbuf, void __user *ubuf)
 792 {
 793         int ret;
 794         struct user_sve_header header;
 795         unsigned int vq;
 796         unsigned long start, end;
 797
 798         if (!system_supports_sve())
 799                 return -EINVAL;
 800
 801         /* Header */
 802         sve_init_header_from_task(&header, target);
 803         vq = sve_vq_from_vl(header.vl);
 804
 805         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &header,
 806                                   0, sizeof(header));
 807         if (ret)
 808                 return ret;
 809
 810         if (target == current)
 811                 fpsimd_preserve_current_state();
 812
 813         /* Registers: FPSIMD-only case */
 814
 815         BUILD_BUG_ON(SVE_PT_FPSIMD_OFFSET != sizeof(header));
 816         if ((header.flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD)
 817                 return __fpr_get(target, regset, pos, count, kbuf, ubuf,
 818                                  SVE_PT_FPSIMD_OFFSET);
 819
 820         /* Otherwise: full SVE case */
 821
 822         BUILD_BUG_ON(SVE_PT_SVE_OFFSET != sizeof(header));
 823         start = SVE_PT_SVE_OFFSET;
 824         end = SVE_PT_SVE_FFR_OFFSET(vq) + SVE_PT_SVE_FFR_SIZE(vq);
 825         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 826                                   target->thread.sve_state,
 827                                   start, end);
 828         if (ret)
 829                 return ret;
 830
 831         start = end;
 832         end = SVE_PT_SVE_FPSR_OFFSET(vq);
 833         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 834                                        start, end);
 835         if (ret)
 836                 return ret;
 837
 838         /*
 839          * Copy fpsr, and fpcr which must follow contiguously in
 840          * struct fpsimd_state:
 841          */
 842         start = end;
 843         end = SVE_PT_SVE_FPCR_OFFSET(vq) + SVE_PT_SVE_FPCR_SIZE;
 844         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 845                                   &target->thread.fpsimd_state.fpsr,
 846                                   start, end);
 847         if (ret)
 848                 return ret;
 849
 850         start = end;
 851         end = sve_size_from_header(&header);
 852         return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 853                                         start, end);
 854 }
 855
 856 static int sve_set(struct task_struct *target,
 857                    const struct user_regset *regset,
 858                    unsigned int pos, unsigned int count,
 859                    const void *kbuf, const void __user *ubuf)
 860 {
 861         int ret;
 862         struct user_sve_header header;
 863         unsigned int vq;
 864         unsigned long start, end;
 865
 866         if (!system_supports_sve())
 867                 return -EINVAL;
 868
 869         /* Header */
 870         if (count < sizeof(header))
 871                 return -EINVAL;
 872         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &header,
 873                                  0, sizeof(header));
 874         if (ret)
 875                 goto out;
 876
 877         /*
 878          * Apart from PT_SVE_REGS_MASK, all PT_SVE_* flags are consumed by
 879          * sve_set_vector_length(), which will also validate them for us:
 880          */
 881         ret = sve_set_vector_length(target, header.vl,
 882                 ((unsigned long)header.flags & ~SVE_PT_REGS_MASK) << 16);
 883         if (ret)
 884                 goto out;
 885
 886         /* Actual VL set may be less than the user asked for: */
 887         vq = sve_vq_from_vl(target->thread.sve_vl);
 888
 889         /* Registers: FPSIMD-only case */
 890
 891         BUILD_BUG_ON(SVE_PT_FPSIMD_OFFSET != sizeof(header));
 892         if ((header.flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD) {
 893                 ret = __fpr_set(target, regset, pos, count, kbuf, ubuf,
 894                                 SVE_PT_FPSIMD_OFFSET);
 895                 clear_tsk_thread_flag(target, TIF_SVE);
 896                 goto out;
 897         }
 898
 899         /* Otherwise: full SVE case */
 900
 901         /*
 902          * If setting a different VL from the requested VL and there is
 903          * register data, the data layout will be wrong: don't even
 904          * try to set the registers in this case.
 905          */
 906         if (count && vq != sve_vq_from_vl(header.vl)) {
 907                 ret = -EIO;
 908                 goto out;
 909         }
 910
 911         sve_alloc(target);
 912
 913         /*
 914          * Ensure target->thread.sve_state is up to date with target's
 915          * FPSIMD regs, so that a short copyin leaves trailing registers
 916          * unmodified.
 917          */
 918         fpsimd_sync_to_sve(target);
 919         set_tsk_thread_flag(target, TIF_SVE);
 920
 921         BUILD_BUG_ON(SVE_PT_SVE_OFFSET != sizeof(header));
 922         start = SVE_PT_SVE_OFFSET;
 923         end = SVE_PT_SVE_FFR_OFFSET(vq) + SVE_PT_SVE_FFR_SIZE(vq);
 924         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 925                                  target->thread.sve_state,
 926                                  start, end);
 927         if (ret)
 928                 goto out;
 929
 930         start = end;
 931         end = SVE_PT_SVE_FPSR_OFFSET(vq);
 932         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 933                                         start, end);
 934         if (ret)
 935                 goto out;
 936
 937         /*
 938          * Copy fpsr, and fpcr which must follow contiguously in
 939          * struct fpsimd_state:
 940          */
 941         start = end;
 942         end = SVE_PT_SVE_FPCR_OFFSET(vq) + SVE_PT_SVE_FPCR_SIZE;
 943         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 944                                  &target->thread.fpsimd_state.fpsr,
 945                                  start, end);
 946
 947 out:
 948         fpsimd_flush_task_state(target);
 949         return ret;
 950 }
 951
 952 #endif /* CONFIG_ARM64_SVE */
 953
 954 enum aarch64_regset {
 955         REGSET_GPR,
 956         REGSET_FPR,
 957         REGSET_TLS,
 958 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 959         REGSET_HW_BREAK,
 960         REGSET_HW_WATCH,
 961 #endif
 962         REGSET_SYSTEM_CALL,
 963 #ifdef CONFIG_ARM64_SVE
 964         REGSET_SVE,
 965 #endif
 966 };
 967
 968 static const struct user_regset aarch64_regsets[] = {
 969         [REGSET_GPR] = {
 970                 .core_note_type = NT_PRSTATUS,
 971                 .n = sizeof(struct user_pt_regs) / sizeof(u64),
 972                 .size = sizeof(u64),
 973                 .align = sizeof(u64),
 974                 .get = gpr_get,
 975                 .set = gpr_set
 976         },
 977         [REGSET_FPR] = {
 978                 .core_note_type = NT_PRFPREG,
 979                 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
 980                 /*
 981                  * We pretend we have 32-bit registers because the fpsr and
 982                  * fpcr are 32-bits wide.
 983                  */
 984                 .size = sizeof(u32),
 985                 .align = sizeof(u32),
 986                 .get = fpr_get,
 987                 .set = fpr_set
 988         },
 989         [REGSET_TLS] = {
 990                 .core_note_type = NT_ARM_TLS,
 991                 .n = 1,
 992                 .size = sizeof(void *),
 993                 .align = sizeof(void *),
 994                 .get = tls_get,
 995                 .set = tls_set,
 996         },
 997 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 998         [REGSET_HW_BREAK] = {
 999                 .core_note_type = NT_ARM_HW_BREAK,
1000                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1001                 .size = sizeof(u32),
1002                 .align = sizeof(u32),
1003                 .get = hw_break_get,
1004                 .set = hw_break_set,
1005         },
1006         [REGSET_HW_WATCH] = {
1007                 .core_note_type = NT_ARM_HW_WATCH,
1008                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1009                 .size = sizeof(u32),
1010                 .align = sizeof(u32),
1011                 .get = hw_break_get,
1012                 .set = hw_break_set,
1013         },
1014 #endif
1015         [REGSET_SYSTEM_CALL] = {
1016                 .core_note_type = NT_ARM_SYSTEM_CALL,
1017                 .n = 1,
1018                 .size = sizeof(int),
1019                 .align = sizeof(int),
1020                 .get = system_call_get,
1021                 .set = system_call_set,
1022         },
1023 #ifdef CONFIG_ARM64_SVE
1024         [REGSET_SVE] = { /* Scalable Vector Extension */
1025                 .core_note_type = NT_ARM_SVE,
1026                 .n = DIV_ROUND_UP(SVE_PT_SIZE(SVE_VQ_MAX, SVE_PT_REGS_SVE),
1027                                   SVE_VQ_BYTES),
1028                 .size = SVE_VQ_BYTES,
1029                 .align = SVE_VQ_BYTES,
1030                 .get = sve_get,
1031                 .set = sve_set,
1032                 .get_size = sve_get_size,
1033         },
1034 #endif
1035 };
1036
1037 static const struct user_regset_view user_aarch64_view = {
1038         .name = "aarch64", .e_machine = EM_AARCH64,
1039         .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
1040 };
1041
1042 #ifdef CONFIG_COMPAT
1043 #include <linux/compat.h>
1044
1045 enum compat_regset {
1046         REGSET_COMPAT_GPR,
1047         REGSET_COMPAT_VFP,
1048 };
1049
1050 static int compat_gpr_get(struct task_struct *target,
1051                           const struct user_regset *regset,
1052                           unsigned int pos, unsigned int count,
1053                           void *kbuf, void __user *ubuf)
1054 {
1055         int ret = 0;
1056         unsigned int i, start, num_regs;
1057
1058         /* Calculate the number of AArch32 registers contained in count */
1059         num_regs = count / regset->size;
1060
1061         /* Convert pos into an register number */
1062         start = pos / regset->size;
1063
1064         if (start + num_regs > regset->n)
1065                 return -EIO;
1066
1067         for (i = 0; i < num_regs; ++i) {
1068                 unsigned int idx = start + i;
1069                 compat_ulong_t reg;
1070
1071                 switch (idx) {
1072                 case 15:
1073                         reg = task_pt_regs(target)->pc;
1074                         break;
1075                 case 16:
1076                         reg = task_pt_regs(target)->pstate;
1077                         break;
1078                 case 17:
1079                         reg = task_pt_regs(target)->orig_x0;
1080                         break;
1081                 default:
1082                         reg = task_pt_regs(target)->regs[idx];
1083                 }
1084
1085                 if (kbuf) {
1086                         memcpy(kbuf, &reg, sizeof(reg));
1087                         kbuf += sizeof(reg);
1088                 } else {
1089                         ret = copy_to_user(ubuf, &reg, sizeof(reg));
1090                         if (ret) {
1091                                 ret = -EFAULT;
1092                                 break;
1093                         }
1094
1095                         ubuf += sizeof(reg);
1096                 }
1097         }
1098
1099         return ret;
1100 }
1101
1102 static int compat_gpr_set(struct task_struct *target,
1103                           const struct user_regset *regset,
1104                           unsigned int pos, unsigned int count,
1105                           const void *kbuf, const void __user *ubuf)
1106 {
1107         struct pt_regs newregs;
1108         int ret = 0;
1109         unsigned int i, start, num_regs;
1110
1111         /* Calculate the number of AArch32 registers contained in count */
1112         num_regs = count / regset->size;
1113
1114         /* Convert pos into an register number */
1115         start = pos / regset->size;
1116
1117         if (start + num_regs > regset->n)
1118                 return -EIO;
1119
1120         newregs = *task_pt_regs(target);
1121
1122         for (i = 0; i < num_regs; ++i) {
1123                 unsigned int idx = start + i;
1124                 compat_ulong_t reg;
1125
1126                 if (kbuf) {
1127                         memcpy(&reg, kbuf, sizeof(reg));
1128                         kbuf += sizeof(reg);
1129                 } else {
1130                         ret = copy_from_user(&reg, ubuf, sizeof(reg));
1131                         if (ret) {
1132                                 ret = -EFAULT;
1133                                 break;
1134                         }
1135
1136                         ubuf += sizeof(reg);
1137                 }
1138
1139                 switch (idx) {
1140                 case 15:
1141                         newregs.pc = reg;
1142                         break;
1143                 case 16:
1144                         newregs.pstate = reg;
1145                         break;
1146                 case 17:
1147                         newregs.orig_x0 = reg;
1148                         break;
1149                 default:
1150                         newregs.regs[idx] = reg;
1151                 }
1152
1153         }
1154
1155         if (valid_user_regs(&newregs.user_regs, target))
1156                 *task_pt_regs(target) = newregs;
1157         else
1158                 ret = -EINVAL;
1159
1160         return ret;
1161 }
1162
1163 static int compat_vfp_get(struct task_struct *target,
1164                           const struct user_regset *regset,
1165                           unsigned int pos, unsigned int count,
1166                           void *kbuf, void __user *ubuf)
1167 {
1168         struct user_fpsimd_state *uregs;
1169         compat_ulong_t fpscr;
1170         int ret, vregs_end_pos;
1171
1172         uregs = &target->thread.fpsimd_state.user_fpsimd;
1173
1174         if (target == current)
1175                 fpsimd_preserve_current_state();
1176
1177         /*
1178          * The VFP registers are packed into the fpsimd_state, so they all sit
1179          * nicely together for us. We just need to create the fpscr separately.
1180          */
1181         vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t);
1182         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs,
1183                                   0, vregs_end_pos);
1184
1185         if (count && !ret) {
1186                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
1187                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
1188
1189                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &fpscr,
1190                                           vregs_end_pos, VFP_STATE_SIZE);
1191         }
1192
1193         return ret;
1194 }
1195
1196 static int compat_vfp_set(struct task_struct *target,
1197                           const struct user_regset *regset,
1198                           unsigned int pos, unsigned int count,
1199                           const void *kbuf, const void __user *ubuf)
1200 {
1201         struct user_fpsimd_state *uregs;
1202         compat_ulong_t fpscr;
1203         int ret, vregs_end_pos;
1204
1205         uregs = &target->thread.fpsimd_state.user_fpsimd;
1206
1207         vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t);
1208         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
1209                                  vregs_end_pos);
1210
1211         if (count && !ret) {
1212                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpscr,
1213                                          vregs_end_pos, VFP_STATE_SIZE);
1214                 if (!ret) {
1215                         uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
1216                         uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
1217                 }
1218         }
1219
1220         fpsimd_flush_task_state(target);
1221         return ret;
1222 }
1223
1224 static int compat_tls_get(struct task_struct *target,
1225                           const struct user_regset *regset, unsigned int pos,
1226                           unsigned int count, void *kbuf, void __user *ubuf)
1227 {
1228         compat_ulong_t tls = (compat_ulong_t)target->thread.tp_value;
1229         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
1230 }
1231
1232 static int compat_tls_set(struct task_struct *target,
1233                           const struct user_regset *regset, unsigned int pos,
1234                           unsigned int count, const void *kbuf,
1235                           const void __user *ubuf)
1236 {
1237         int ret;
1238         compat_ulong_t tls = target->thread.tp_value;
1239
1240         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
1241         if (ret)
1242                 return ret;
1243
1244         target->thread.tp_value = tls;
1245         return ret;
1246 }
1247
1248 static const struct user_regset aarch32_regsets[] = {
1249         [REGSET_COMPAT_GPR] = {
1250                 .core_note_type = NT_PRSTATUS,
1251                 .n = COMPAT_ELF_NGREG,
1252                 .size = sizeof(compat_elf_greg_t),
1253                 .align = sizeof(compat_elf_greg_t),
1254                 .get = compat_gpr_get,
1255                 .set = compat_gpr_set
1256         },
1257         [REGSET_COMPAT_VFP] = {
1258                 .core_note_type = NT_ARM_VFP,
1259                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
1260                 .size = sizeof(compat_ulong_t),
1261                 .align = sizeof(compat_ulong_t),
1262                 .get = compat_vfp_get,
1263                 .set = compat_vfp_set
1264         },
1265 };
1266
1267 static const struct user_regset_view user_aarch32_view = {
1268         .name = "aarch32", .e_machine = EM_ARM,
1269         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
1270 };
1271
1272 static const struct user_regset aarch32_ptrace_regsets[] = {
1273         [REGSET_GPR] = {
1274                 .core_note_type = NT_PRSTATUS,
1275                 .n = COMPAT_ELF_NGREG,
1276                 .size = sizeof(compat_elf_greg_t),
1277                 .align = sizeof(compat_elf_greg_t),
1278                 .get = compat_gpr_get,
1279                 .set = compat_gpr_set
1280         },
1281         [REGSET_FPR] = {
1282                 .core_note_type = NT_ARM_VFP,
1283                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
1284                 .size = sizeof(compat_ulong_t),
1285                 .align = sizeof(compat_ulong_t),
1286                 .get = compat_vfp_get,
1287                 .set = compat_vfp_set
1288         },
1289         [REGSET_TLS] = {
1290                 .core_note_type = NT_ARM_TLS,
1291                 .n = 1,
1292                 .size = sizeof(compat_ulong_t),
1293                 .align = sizeof(compat_ulong_t),
1294                 .get = compat_tls_get,
1295                 .set = compat_tls_set,
1296         },
1297 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1298         [REGSET_HW_BREAK] = {
1299                 .core_note_type = NT_ARM_HW_BREAK,
1300                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1301                 .size = sizeof(u32),
1302                 .align = sizeof(u32),
1303                 .get = hw_break_get,
1304                 .set = hw_break_set,
1305         },
1306         [REGSET_HW_WATCH] = {
1307                 .core_note_type = NT_ARM_HW_WATCH,
1308                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1309                 .size = sizeof(u32),
1310                 .align = sizeof(u32),
1311                 .get = hw_break_get,
1312                 .set = hw_break_set,
1313         },
1314 #endif
1315         [REGSET_SYSTEM_CALL] = {
1316                 .core_note_type = NT_ARM_SYSTEM_CALL,
1317                 .n = 1,
1318                 .size = sizeof(int),
1319                 .align = sizeof(int),
1320                 .get = system_call_get,
1321                 .set = system_call_set,
1322         },
1323 };
1324
1325 static const struct user_regset_view user_aarch32_ptrace_view = {
1326         .name = "aarch32", .e_machine = EM_ARM,
1327         .regsets = aarch32_ptrace_regsets, .n = ARRAY_SIZE(aarch32_ptrace_regsets)
1328 };
1329
1330 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
1331                                    compat_ulong_t __user *ret)
1332 {
1333         compat_ulong_t tmp;
1334
1335         if (off & 3)
1336                 return -EIO;
1337
1338         if (off == COMPAT_PT_TEXT_ADDR)
1339                 tmp = tsk->mm->start_code;
1340         else if (off == COMPAT_PT_DATA_ADDR)
1341                 tmp = tsk->mm->start_data;
1342         else if (off == COMPAT_PT_TEXT_END_ADDR)
1343                 tmp = tsk->mm->end_code;
1344         else if (off < sizeof(compat_elf_gregset_t))
1345                 return copy_regset_to_user(tsk, &user_aarch32_view,
1346                                            REGSET_COMPAT_GPR, off,
1347                                            sizeof(compat_ulong_t), ret);
1348         else if (off >= COMPAT_USER_SZ)
1349                 return -EIO;
1350         else
1351                 tmp = 0;
1352
1353         return put_user(tmp, ret);
1354 }
1355
1356 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
1357                                     compat_ulong_t val)
1358 {
1359         int ret;
1360         mm_segment_t old_fs = get_fs();
1361
1362         if (off & 3 || off >= COMPAT_USER_SZ)
1363                 return -EIO;
1364
1365         if (off >= sizeof(compat_elf_gregset_t))
1366                 return 0;
1367
1368         set_fs(KERNEL_DS);
1369         ret = copy_regset_from_user(tsk, &user_aarch32_view,
1370                                     REGSET_COMPAT_GPR, off,
1371                                     sizeof(compat_ulong_t),
1372                                     &val);
1373         set_fs(old_fs);
1374
1375         return ret;
1376 }
1377
1378 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1379
1380 /*
1381  * Convert a virtual register number into an index for a thread_info
1382  * breakpoint array. Breakpoints are identified using positive numbers
1383  * whilst watchpoints are negative. The registers are laid out as pairs
1384  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
1385  * Register 0 is reserved for describing resource information.
1386  */
1387 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
1388 {
1389         return (abs(num) - 1) >> 1;
1390 }
1391
1392 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
1393 {
1394         u8 num_brps, num_wrps, debug_arch, wp_len;
1395         u32 reg = 0;
1396
1397         num_brps        = hw_breakpoint_slots(TYPE_INST);
1398         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
1399
1400         debug_arch      = debug_monitors_arch();
1401         wp_len          = 8;
1402         reg             |= debug_arch;
1403         reg             <<= 8;
1404         reg             |= wp_len;
1405         reg             <<= 8;
1406         reg             |= num_wrps;
1407         reg             <<= 8;
1408         reg             |= num_brps;
1409
1410         *kdata = reg;
1411         return 0;
1412 }
1413
1414 static int compat_ptrace_hbp_get(unsigned int note_type,
1415                                  struct task_struct *tsk,
1416                                  compat_long_t num,
1417                                  u32 *kdata)
1418 {
1419         u64 addr = 0;
1420         u32 ctrl = 0;
1421
1422         int err, idx = compat_ptrace_hbp_num_to_idx(num);;
1423
1424         if (num & 1) {
1425                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
1426                 *kdata = (u32)addr;
1427         } else {
1428                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
1429                 *kdata = ctrl;
1430         }
1431
1432         return err;
1433 }
1434
1435 static int compat_ptrace_hbp_set(unsigned int note_type,
1436                                  struct task_struct *tsk,
1437                                  compat_long_t num,
1438                                  u32 *kdata)
1439 {
1440         u64 addr;
1441         u32 ctrl;
1442
1443         int err, idx = compat_ptrace_hbp_num_to_idx(num);
1444
1445         if (num & 1) {
1446                 addr = *kdata;
1447                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
1448         } else {
1449                 ctrl = *kdata;
1450                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
1451         }
1452
1453         return err;
1454 }
1455
1456 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
1457                                     compat_ulong_t __user *data)
1458 {
1459         int ret;
1460         u32 kdata;
1461         mm_segment_t old_fs = get_fs();
1462
1463         set_fs(KERNEL_DS);
1464         /* Watchpoint */
1465         if (num < 0) {
1466                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
1467         /* Resource info */
1468         } else if (num == 0) {
1469                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
1470         /* Breakpoint */
1471         } else {
1472                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
1473         }
1474         set_fs(old_fs);
1475
1476         if (!ret)
1477                 ret = put_user(kdata, data);
1478
1479         return ret;
1480 }
1481
1482 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
1483                                     compat_ulong_t __user *data)
1484 {
1485         int ret;
1486         u32 kdata = 0;
1487         mm_segment_t old_fs = get_fs();
1488
1489         if (num == 0)
1490                 return 0;
1491
1492         ret = get_user(kdata, data);
1493         if (ret)
1494                 return ret;
1495
1496         set_fs(KERNEL_DS);
1497         if (num < 0)
1498                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
1499         else
1500                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
1501         set_fs(old_fs);
1502
1503         return ret;
1504 }
1505 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
1506
1507 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1508                         compat_ulong_t caddr, compat_ulong_t cdata)
1509 {
1510         unsigned long addr = caddr;
1511         unsigned long data = cdata;
1512         void __user *datap = compat_ptr(data);
1513         int ret;
1514
1515         switch (request) {
1516                 case PTRACE_PEEKUSR:
1517                         ret = compat_ptrace_read_user(child, addr, datap);
1518                         break;
1519
1520                 case PTRACE_POKEUSR:
1521                         ret = compat_ptrace_write_user(child, addr, data);
1522                         break;
1523
1524                 case COMPAT_PTRACE_GETREGS:
1525                         ret = copy_regset_to_user(child,
1526                                                   &user_aarch32_view,
1527                                                   REGSET_COMPAT_GPR,
1528                                                   0, sizeof(compat_elf_gregset_t),
1529                                                   datap);
1530                         break;
1531
1532                 case COMPAT_PTRACE_SETREGS:
1533                         ret = copy_regset_from_user(child,
1534                                                     &user_aarch32_view,
1535                                                     REGSET_COMPAT_GPR,
1536                                                     0, sizeof(compat_elf_gregset_t),
1537                                                     datap);
1538                         break;
1539
1540                 case COMPAT_PTRACE_GET_THREAD_AREA:
1541                         ret = put_user((compat_ulong_t)child->thread.tp_value,
1542                                        (compat_ulong_t __user *)datap);
1543                         break;
1544
1545                 case COMPAT_PTRACE_SET_SYSCALL:
1546                         task_pt_regs(child)->syscallno = data;
1547                         ret = 0;
1548                         break;
1549
1550                 case COMPAT_PTRACE_GETVFPREGS:
1551                         ret = copy_regset_to_user(child,
1552                                                   &user_aarch32_view,
1553                                                   REGSET_COMPAT_VFP,
1554                                                   0, VFP_STATE_SIZE,
1555                                                   datap);
1556                         break;
1557
1558                 case COMPAT_PTRACE_SETVFPREGS:
1559                         ret = copy_regset_from_user(child,
1560                                                     &user_aarch32_view,
1561                                                     REGSET_COMPAT_VFP,
1562                                                     0, VFP_STATE_SIZE,
1563                                                     datap);
1564                         break;
1565
1566 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1567                 case COMPAT_PTRACE_GETHBPREGS:
1568                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1569                         break;
1570
1571                 case COMPAT_PTRACE_SETHBPREGS:
1572                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1573                         break;
1574 #endif
1575
1576                 default:
1577                         ret = compat_ptrace_request(child, request, addr,
1578                                                     data);
1579                         break;
1580         }
1581
1582         return ret;
1583 }
1584 #endif /* CONFIG_COMPAT */
1585
1586 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1587 {
1588 #ifdef CONFIG_COMPAT
1589         /*
1590          * Core dumping of 32-bit tasks or compat ptrace requests must use the
1591          * user_aarch32_view compatible with arm32. Native ptrace requests on
1592          * 32-bit children use an extended user_aarch32_ptrace_view to allow
1593          * access to the TLS register.
1594          */
1595         if (is_compat_task())
1596                 return &user_aarch32_view;
1597         else if (is_compat_thread(task_thread_info(task)))
1598                 return &user_aarch32_ptrace_view;
1599 #endif
1600         return &user_aarch64_view;
1601 }
1602
1603 long arch_ptrace(struct task_struct *child, long request,
1604                  unsigned long addr, unsigned long data)
1605 {
1606         return ptrace_request(child, request, addr, data);
1607 }
1608
1609 enum ptrace_syscall_dir {
1610         PTRACE_SYSCALL_ENTER = 0,
1611         PTRACE_SYSCALL_EXIT,
1612 };
1613
1614 static void tracehook_report_syscall(struct pt_regs *regs,
1615                                      enum ptrace_syscall_dir dir)
1616 {
1617         int regno;
1618         unsigned long saved_reg;
1619
1620         /*
1621          * A scratch register (ip(r12) on AArch32, x7 on AArch64) is
1622          * used to denote syscall entry/exit:
1623          */
1624         regno = (is_compat_task() ? 12 : 7);
1625         saved_reg = regs->regs[regno];
1626         regs->regs[regno] = dir;
1627
1628         if (dir == PTRACE_SYSCALL_EXIT)
1629                 tracehook_report_syscall_exit(regs, 0);
1630         else if (tracehook_report_syscall_entry(regs))
1631                 forget_syscall(regs);
1632
1633         regs->regs[regno] = saved_reg;
1634 }
1635
1636 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
1637 {
1638         if (test_thread_flag(TIF_SYSCALL_TRACE))
1639                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1640
1641         /* Do the secure computing after ptrace; failures should be fast. */
1642         if (secure_computing(NULL) == -1)
1643                 return -1;
1644
1645         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1646                 trace_sys_enter(regs, regs->syscallno);
1647
1648         audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1],
1649                             regs->regs[2], regs->regs[3]);
1650
1651         return regs->syscallno;
1652 }
1653
1654 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
1655 {
1656         audit_syscall_exit(regs);
1657
1658         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1659                 trace_sys_exit(regs, regs_return_value(regs));
1660
1661         if (test_thread_flag(TIF_SYSCALL_TRACE))
1662                 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1663 }
1664
1665 /*
1666  * Bits which are always architecturally RES0 per ARM DDI 0487A.h
1667  * Userspace cannot use these until they have an architectural meaning.
1668  * We also reserve IL for the kernel; SS is handled dynamically.
1669  */
1670 #define SPSR_EL1_AARCH64_RES0_BITS \
1671         (GENMASK_ULL(63,32) | GENMASK_ULL(27, 22) | GENMASK_ULL(20, 10) | \
1672          GENMASK_ULL(5, 5))
1673 #define SPSR_EL1_AARCH32_RES0_BITS \
1674         (GENMASK_ULL(63,32) | GENMASK_ULL(24, 22) | GENMASK_ULL(20,20))
1675
1676 static int valid_compat_regs(struct user_pt_regs *regs)
1677 {
1678         regs->pstate &= ~SPSR_EL1_AARCH32_RES0_BITS;
1679
1680         if (!system_supports_mixed_endian_el0()) {
1681                 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
1682                         regs->pstate |= COMPAT_PSR_E_BIT;
1683                 else
1684                         regs->pstate &= ~COMPAT_PSR_E_BIT;
1685         }
1686
1687         if (user_mode(regs) && (regs->pstate & PSR_MODE32_BIT) &&
1688             (regs->pstate & COMPAT_PSR_A_BIT) == 0 &&
1689             (regs->pstate & COMPAT_PSR_I_BIT) == 0 &&
1690             (regs->pstate & COMPAT_PSR_F_BIT) == 0) {
1691                 return 1;
1692         }
1693
1694         /*
1695          * Force PSR to a valid 32-bit EL0t, preserving the same bits as
1696          * arch/arm.
1697          */
1698         regs->pstate &= COMPAT_PSR_N_BIT | COMPAT_PSR_Z_BIT |
1699                         COMPAT_PSR_C_BIT | COMPAT_PSR_V_BIT |
1700                         COMPAT_PSR_Q_BIT | COMPAT_PSR_IT_MASK |
1701                         COMPAT_PSR_GE_MASK | COMPAT_PSR_E_BIT |
1702                         COMPAT_PSR_T_BIT;
1703         regs->pstate |= PSR_MODE32_BIT;
1704
1705         return 0;
1706 }
1707
1708 static int valid_native_regs(struct user_pt_regs *regs)
1709 {
1710         regs->pstate &= ~SPSR_EL1_AARCH64_RES0_BITS;
1711
1712         if (user_mode(regs) && !(regs->pstate & PSR_MODE32_BIT) &&
1713             (regs->pstate & PSR_D_BIT) == 0 &&
1714             (regs->pstate & PSR_A_BIT) == 0 &&
1715             (regs->pstate & PSR_I_BIT) == 0 &&
1716             (regs->pstate & PSR_F_BIT) == 0) {
1717                 return 1;
1718         }
1719
1720         /* Force PSR to a valid 64-bit EL0t */
1721         regs->pstate &= PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT;
1722
1723         return 0;
1724 }
1725
1726 /*
1727  * Are the current registers suitable for user mode? (used to maintain
1728  * security in signal handlers)
1729  */
1730 int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task)
1731 {
1732         if (!test_tsk_thread_flag(task, TIF_SINGLESTEP))
1733                 regs->pstate &= ~DBG_SPSR_SS;
1734
1735         if (is_compat_thread(task_thread_info(task)))
1736                 return valid_compat_regs(regs);
1737         else
1738                 return valid_native_regs(regs);
1739 }