arch/arm64/kernel/ptrace.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Based on arch/arm/kernel/ptrace.c
   4  *
   5  * By Ross Biro 1/23/92
   6  * edited by Linus Torvalds
   7  * ARM modifications Copyright (C) 2000 Russell King
   8  * Copyright (C) 2012 ARM Ltd.
   9  */
  10
  11 #include <linux/audit.h>
  12 #include <linux/compat.h>
  13 #include <linux/kernel.h>
  14 #include <linux/sched/signal.h>
  15 #include <linux/sched/task_stack.h>
  16 #include <linux/mm.h>
  17 #include <linux/nospec.h>
  18 #include <linux/smp.h>
  19 #include <linux/ptrace.h>
  20 #include <linux/user.h>
  21 #include <linux/seccomp.h>
  22 #include <linux/security.h>
  23 #include <linux/init.h>
  24 #include <linux/signal.h>
  25 #include <linux/string.h>
  26 #include <linux/uaccess.h>
  27 #include <linux/perf_event.h>
  28 #include <linux/hw_breakpoint.h>
  29 #include <linux/regset.h>
  30 #include <linux/tracehook.h>
  31 #include <linux/elf.h>
  32
  33 #include <asm/compat.h>
  34 #include <asm/cpufeature.h>
  35 #include <asm/debug-monitors.h>
  36 #include <asm/fpsimd.h>
  37 #include <asm/mte.h>
  38 #include <asm/pointer_auth.h>
  39 #include <asm/stacktrace.h>
  40 #include <asm/syscall.h>
  41 #include <asm/traps.h>
  42 #include <asm/system_misc.h>
  43
  44 #define CREATE_TRACE_POINTS
  45 #include <trace/events/syscalls.h>
  46
  47 struct pt_regs_offset {
  48         const char *name;
  49         int offset;
  50 };
  51
  52 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  53 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  54 #define GPR_OFFSET_NAME(r) \
  55         {.name = "x" #r, .offset = offsetof(struct pt_regs, regs[r])}
  56
  57 static const struct pt_regs_offset regoffset_table[] = {
  58         GPR_OFFSET_NAME(0),
  59         GPR_OFFSET_NAME(1),
  60         GPR_OFFSET_NAME(2),
  61         GPR_OFFSET_NAME(3),
  62         GPR_OFFSET_NAME(4),
  63         GPR_OFFSET_NAME(5),
  64         GPR_OFFSET_NAME(6),
  65         GPR_OFFSET_NAME(7),
  66         GPR_OFFSET_NAME(8),
  67         GPR_OFFSET_NAME(9),
  68         GPR_OFFSET_NAME(10),
  69         GPR_OFFSET_NAME(11),
  70         GPR_OFFSET_NAME(12),
  71         GPR_OFFSET_NAME(13),
  72         GPR_OFFSET_NAME(14),
  73         GPR_OFFSET_NAME(15),
  74         GPR_OFFSET_NAME(16),
  75         GPR_OFFSET_NAME(17),
  76         GPR_OFFSET_NAME(18),
  77         GPR_OFFSET_NAME(19),
  78         GPR_OFFSET_NAME(20),
  79         GPR_OFFSET_NAME(21),
  80         GPR_OFFSET_NAME(22),
  81         GPR_OFFSET_NAME(23),
  82         GPR_OFFSET_NAME(24),
  83         GPR_OFFSET_NAME(25),
  84         GPR_OFFSET_NAME(26),
  85         GPR_OFFSET_NAME(27),
  86         GPR_OFFSET_NAME(28),
  87         GPR_OFFSET_NAME(29),
  88         GPR_OFFSET_NAME(30),
  89         {.name = "lr", .offset = offsetof(struct pt_regs, regs[30])},
  90         REG_OFFSET_NAME(sp),
  91         REG_OFFSET_NAME(pc),
  92         REG_OFFSET_NAME(pstate),
  93         REG_OFFSET_END,
  94 };
  95
  96 /**
  97  * regs_query_register_offset() - query register offset from its name
  98  * @name:       the name of a register
  99  *
 100  * regs_query_register_offset() returns the offset of a register in struct
 101  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 102  */
 103 int regs_query_register_offset(const char *name)
 104 {
 105         const struct pt_regs_offset *roff;
 106
 107         for (roff = regoffset_table; roff->name != NULL; roff++)
 108                 if (!strcmp(roff->name, name))
 109                         return roff->offset;
 110         return -EINVAL;
 111 }
 112
 113 /**
 114  * regs_within_kernel_stack() - check the address in the stack
 115  * @regs:      pt_regs which contains kernel stack pointer.
 116  * @addr:      address which is checked.
 117  *
 118  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 119  * If @addr is within the kernel stack, it returns true. If not, returns false.
 120  */
 121 static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 122 {
 123         return ((addr & ~(THREAD_SIZE - 1))  ==
 124                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))) ||
 125                 on_irq_stack(addr, NULL);
 126 }
 127
 128 /**
 129  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 130  * @regs:       pt_regs which contains kernel stack pointer.
 131  * @n:          stack entry number.
 132  *
 133  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 134  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 135  * this returns 0.
 136  */
 137 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 138 {
 139         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 140
 141         addr += n;
 142         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 143                 return *addr;
 144         else
 145                 return 0;
 146 }
 147
 148 /*
 149  * TODO: does not yet catch signals sent when the child dies.
 150  * in exit.c or in signal.c.
 151  */
 152
 153 /*
 154  * Called by kernel/ptrace.c when detaching..
 155  */
 156 void ptrace_disable(struct task_struct *child)
 157 {
 158         /*
 159          * This would be better off in core code, but PTRACE_DETACH has
 160          * grown its fair share of arch-specific worts and changing it
 161          * is likely to cause regressions on obscure architectures.
 162          */
 163         user_disable_single_step(child);
 164 }
 165
 166 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 167 /*
 168  * Handle hitting a HW-breakpoint.
 169  */
 170 static void ptrace_hbptriggered(struct perf_event *bp,
 171                                 struct perf_sample_data *data,
 172                                 struct pt_regs *regs)
 173 {
 174         struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
 175         const char *desc = "Hardware breakpoint trap (ptrace)";
 176
 177 #ifdef CONFIG_COMPAT
 178         if (is_compat_task()) {
 179                 int si_errno = 0;
 180                 int i;
 181
 182                 for (i = 0; i < ARM_MAX_BRP; ++i) {
 183                         if (current->thread.debug.hbp_break[i] == bp) {
 184                                 si_errno = (i << 1) + 1;
 185                                 break;
 186                         }
 187                 }
 188
 189                 for (i = 0; i < ARM_MAX_WRP; ++i) {
 190                         if (current->thread.debug.hbp_watch[i] == bp) {
 191                                 si_errno = -((i << 1) + 1);
 192                                 break;
 193                         }
 194                 }
 195                 arm64_force_sig_ptrace_errno_trap(si_errno, bkpt->trigger,
 196                                                   desc);
 197                 return;
 198         }
 199 #endif
 200         arm64_force_sig_fault(SIGTRAP, TRAP_HWBKPT, bkpt->trigger, desc);
 201 }
 202
 203 /*
 204  * Unregister breakpoints from this task and reset the pointers in
 205  * the thread_struct.
 206  */
 207 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 208 {
 209         int i;
 210         struct thread_struct *t = &tsk->thread;
 211
 212         for (i = 0; i < ARM_MAX_BRP; i++) {
 213                 if (t->debug.hbp_break[i]) {
 214                         unregister_hw_breakpoint(t->debug.hbp_break[i]);
 215                         t->debug.hbp_break[i] = NULL;
 216                 }
 217         }
 218
 219         for (i = 0; i < ARM_MAX_WRP; i++) {
 220                 if (t->debug.hbp_watch[i]) {
 221                         unregister_hw_breakpoint(t->debug.hbp_watch[i]);
 222                         t->debug.hbp_watch[i] = NULL;
 223                 }
 224         }
 225 }
 226
 227 void ptrace_hw_copy_thread(struct task_struct *tsk)
 228 {
 229         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 230 }
 231
 232 static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
 233                                                struct task_struct *tsk,
 234                                                unsigned long idx)
 235 {
 236         struct perf_event *bp = ERR_PTR(-EINVAL);
 237
 238         switch (note_type) {
 239         case NT_ARM_HW_BREAK:
 240                 if (idx >= ARM_MAX_BRP)
 241                         goto out;
 242                 idx = array_index_nospec(idx, ARM_MAX_BRP);
 243                 bp = tsk->thread.debug.hbp_break[idx];
 244                 break;
 245         case NT_ARM_HW_WATCH:
 246                 if (idx >= ARM_MAX_WRP)
 247                         goto out;
 248                 idx = array_index_nospec(idx, ARM_MAX_WRP);
 249                 bp = tsk->thread.debug.hbp_watch[idx];
 250                 break;
 251         }
 252
 253 out:
 254         return bp;
 255 }
 256
 257 static int ptrace_hbp_set_event(unsigned int note_type,
 258                                 struct task_struct *tsk,
 259                                 unsigned long idx,
 260                                 struct perf_event *bp)
 261 {
 262         int err = -EINVAL;
 263
 264         switch (note_type) {
 265         case NT_ARM_HW_BREAK:
 266                 if (idx >= ARM_MAX_BRP)
 267                         goto out;
 268                 idx = array_index_nospec(idx, ARM_MAX_BRP);
 269                 tsk->thread.debug.hbp_break[idx] = bp;
 270                 err = 0;
 271                 break;
 272         case NT_ARM_HW_WATCH:
 273                 if (idx >= ARM_MAX_WRP)
 274                         goto out;
 275                 idx = array_index_nospec(idx, ARM_MAX_WRP);
 276                 tsk->thread.debug.hbp_watch[idx] = bp;
 277                 err = 0;
 278                 break;
 279         }
 280
 281 out:
 282         return err;
 283 }
 284
 285 static struct perf_event *ptrace_hbp_create(unsigned int note_type,
 286                                             struct task_struct *tsk,
 287                                             unsigned long idx)
 288 {
 289         struct perf_event *bp;
 290         struct perf_event_attr attr;
 291         int err, type;
 292
 293         switch (note_type) {
 294         case NT_ARM_HW_BREAK:
 295                 type = HW_BREAKPOINT_X;
 296                 break;
 297         case NT_ARM_HW_WATCH:
 298                 type = HW_BREAKPOINT_RW;
 299                 break;
 300         default:
 301                 return ERR_PTR(-EINVAL);
 302         }
 303
 304         ptrace_breakpoint_init(&attr);
 305
 306         /*
 307          * Initialise fields to sane defaults
 308          * (i.e. values that will pass validation).
 309          */
 310         attr.bp_addr    = 0;
 311         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 312         attr.bp_type    = type;
 313         attr.disabled   = 1;
 314
 315         bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk);
 316         if (IS_ERR(bp))
 317                 return bp;
 318
 319         err = ptrace_hbp_set_event(note_type, tsk, idx, bp);
 320         if (err)
 321                 return ERR_PTR(err);
 322
 323         return bp;
 324 }
 325
 326 static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
 327                                      struct arch_hw_breakpoint_ctrl ctrl,
 328                                      struct perf_event_attr *attr)
 329 {
 330         int err, len, type, offset, disabled = !ctrl.enabled;
 331
 332         attr->disabled = disabled;
 333         if (disabled)
 334                 return 0;
 335
 336         err = arch_bp_generic_fields(ctrl, &len, &type, &offset);
 337         if (err)
 338                 return err;
 339
 340         switch (note_type) {
 341         case NT_ARM_HW_BREAK:
 342                 if ((type & HW_BREAKPOINT_X) != type)
 343                         return -EINVAL;
 344                 break;
 345         case NT_ARM_HW_WATCH:
 346                 if ((type & HW_BREAKPOINT_RW) != type)
 347                         return -EINVAL;
 348                 break;
 349         default:
 350                 return -EINVAL;
 351         }
 352
 353         attr->bp_len    = len;
 354         attr->bp_type   = type;
 355         attr->bp_addr   += offset;
 356
 357         return 0;
 358 }
 359
 360 static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info)
 361 {
 362         u8 num;
 363         u32 reg = 0;
 364
 365         switch (note_type) {
 366         case NT_ARM_HW_BREAK:
 367                 num = hw_breakpoint_slots(TYPE_INST);
 368                 break;
 369         case NT_ARM_HW_WATCH:
 370                 num = hw_breakpoint_slots(TYPE_DATA);
 371                 break;
 372         default:
 373                 return -EINVAL;
 374         }
 375
 376         reg |= debug_monitors_arch();
 377         reg <<= 8;
 378         reg |= num;
 379
 380         *info = reg;
 381         return 0;
 382 }
 383
 384 static int ptrace_hbp_get_ctrl(unsigned int note_type,
 385                                struct task_struct *tsk,
 386                                unsigned long idx,
 387                                u32 *ctrl)
 388 {
 389         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 390
 391         if (IS_ERR(bp))
 392                 return PTR_ERR(bp);
 393
 394         *ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0;
 395         return 0;
 396 }
 397
 398 static int ptrace_hbp_get_addr(unsigned int note_type,
 399                                struct task_struct *tsk,
 400                                unsigned long idx,
 401                                u64 *addr)
 402 {
 403         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 404
 405         if (IS_ERR(bp))
 406                 return PTR_ERR(bp);
 407
 408         *addr = bp ? counter_arch_bp(bp)->address : 0;
 409         return 0;
 410 }
 411
 412 static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type,
 413                                                         struct task_struct *tsk,
 414                                                         unsigned long idx)
 415 {
 416         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 417
 418         if (!bp)
 419                 bp = ptrace_hbp_create(note_type, tsk, idx);
 420
 421         return bp;
 422 }
 423
 424 static int ptrace_hbp_set_ctrl(unsigned int note_type,
 425                                struct task_struct *tsk,
 426                                unsigned long idx,
 427                                u32 uctrl)
 428 {
 429         int err;
 430         struct perf_event *bp;
 431         struct perf_event_attr attr;
 432         struct arch_hw_breakpoint_ctrl ctrl;
 433
 434         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 435         if (IS_ERR(bp)) {
 436                 err = PTR_ERR(bp);
 437                 return err;
 438         }
 439
 440         attr = bp->attr;
 441         decode_ctrl_reg(uctrl, &ctrl);
 442         err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
 443         if (err)
 444                 return err;
 445
 446         return modify_user_hw_breakpoint(bp, &attr);
 447 }
 448
 449 static int ptrace_hbp_set_addr(unsigned int note_type,
 450                                struct task_struct *tsk,
 451                                unsigned long idx,
 452                                u64 addr)
 453 {
 454         int err;
 455         struct perf_event *bp;
 456         struct perf_event_attr attr;
 457
 458         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 459         if (IS_ERR(bp)) {
 460                 err = PTR_ERR(bp);
 461                 return err;
 462         }
 463
 464         attr = bp->attr;
 465         attr.bp_addr = addr;
 466         err = modify_user_hw_breakpoint(bp, &attr);
 467         return err;
 468 }
 469
 470 #define PTRACE_HBP_ADDR_SZ      sizeof(u64)
 471 #define PTRACE_HBP_CTRL_SZ      sizeof(u32)
 472 #define PTRACE_HBP_PAD_SZ       sizeof(u32)
 473
 474 static int hw_break_get(struct task_struct *target,
 475                         const struct user_regset *regset,
 476                         struct membuf to)
 477 {
 478         unsigned int note_type = regset->core_note_type;
 479         int ret, idx = 0;
 480         u32 info, ctrl;
 481         u64 addr;
 482
 483         /* Resource info */
 484         ret = ptrace_hbp_get_resource_info(note_type, &info);
 485         if (ret)
 486                 return ret;
 487
 488         membuf_write(&to, &info, sizeof(info));
 489         membuf_zero(&to, sizeof(u32));
 490         /* (address, ctrl) registers */
 491         while (to.left) {
 492                 ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
 493                 if (ret)
 494                         return ret;
 495                 ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
 496                 if (ret)
 497                         return ret;
 498                 membuf_store(&to, addr);
 499                 membuf_store(&to, ctrl);
 500                 membuf_zero(&to, sizeof(u32));
 501                 idx++;
 502         }
 503         return 0;
 504 }
 505
 506 static int hw_break_set(struct task_struct *target,
 507                         const struct user_regset *regset,
 508                         unsigned int pos, unsigned int count,
 509                         const void *kbuf, const void __user *ubuf)
 510 {
 511         unsigned int note_type = regset->core_note_type;
 512         int ret, idx = 0, offset, limit;
 513         u32 ctrl;
 514         u64 addr;
 515
 516         /* Resource info and pad */
 517         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 518         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset);
 519         if (ret)
 520                 return ret;
 521
 522         /* (address, ctrl) registers */
 523         limit = regset->n * regset->size;
 524         while (count && offset < limit) {
 525                 if (count < PTRACE_HBP_ADDR_SZ)
 526                         return -EINVAL;
 527                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
 528                                          offset, offset + PTRACE_HBP_ADDR_SZ);
 529                 if (ret)
 530                         return ret;
 531                 ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
 532                 if (ret)
 533                         return ret;
 534                 offset += PTRACE_HBP_ADDR_SZ;
 535
 536                 if (!count)
 537                         break;
 538                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
 539                                          offset, offset + PTRACE_HBP_CTRL_SZ);
 540                 if (ret)
 541                         return ret;
 542                 ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
 543                 if (ret)
 544                         return ret;
 545                 offset += PTRACE_HBP_CTRL_SZ;
 546
 547                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 548                                                 offset,
 549                                                 offset + PTRACE_HBP_PAD_SZ);
 550                 if (ret)
 551                         return ret;
 552                 offset += PTRACE_HBP_PAD_SZ;
 553                 idx++;
 554         }
 555
 556         return 0;
 557 }
 558 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 559
 560 static int gpr_get(struct task_struct *target,
 561                    const struct user_regset *regset,
 562                    struct membuf to)
 563 {
 564         struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
 565         return membuf_write(&to, uregs, sizeof(*uregs));
 566 }
 567
 568 static int gpr_set(struct task_struct *target, const struct user_regset *regset,
 569                    unsigned int pos, unsigned int count,
 570                    const void *kbuf, const void __user *ubuf)
 571 {
 572         int ret;
 573         struct user_pt_regs newregs = task_pt_regs(target)->user_regs;
 574
 575         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
 576         if (ret)
 577                 return ret;
 578
 579         if (!valid_user_regs(&newregs, target))
 580                 return -EINVAL;
 581
 582         task_pt_regs(target)->user_regs = newregs;
 583         return 0;
 584 }
 585
 586 static int fpr_active(struct task_struct *target, const struct user_regset *regset)
 587 {
 588         if (!system_supports_fpsimd())
 589                 return -ENODEV;
 590         return regset->n;
 591 }
 592
 593 /*
 594  * TODO: update fp accessors for lazy context switching (sync/flush hwstate)
 595  */
 596 static int __fpr_get(struct task_struct *target,
 597                      const struct user_regset *regset,
 598                      struct membuf to)
 599 {
 600         struct user_fpsimd_state *uregs;
 601
 602         sve_sync_to_fpsimd(target);
 603
 604         uregs = &target->thread.uw.fpsimd_state;
 605
 606         return membuf_write(&to, uregs, sizeof(*uregs));
 607 }
 608
 609 static int fpr_get(struct task_struct *target, const struct user_regset *regset,
 610                    struct membuf to)
 611 {
 612         if (!system_supports_fpsimd())
 613                 return -EINVAL;
 614
 615         if (target == current)
 616                 fpsimd_preserve_current_state();
 617
 618         return __fpr_get(target, regset, to);
 619 }
 620
 621 static int __fpr_set(struct task_struct *target,
 622                      const struct user_regset *regset,
 623                      unsigned int pos, unsigned int count,
 624                      const void *kbuf, const void __user *ubuf,
 625                      unsigned int start_pos)
 626 {
 627         int ret;
 628         struct user_fpsimd_state newstate;
 629
 630         /*
 631          * Ensure target->thread.uw.fpsimd_state is up to date, so that a
 632          * short copyin can't resurrect stale data.
 633          */
 634         sve_sync_to_fpsimd(target);
 635
 636         newstate = target->thread.uw.fpsimd_state;
 637
 638         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate,
 639                                  start_pos, start_pos + sizeof(newstate));
 640         if (ret)
 641                 return ret;
 642
 643         target->thread.uw.fpsimd_state = newstate;
 644
 645         return ret;
 646 }
 647
 648 static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 649                    unsigned int pos, unsigned int count,
 650                    const void *kbuf, const void __user *ubuf)
 651 {
 652         int ret;
 653
 654         if (!system_supports_fpsimd())
 655                 return -EINVAL;
 656
 657         ret = __fpr_set(target, regset, pos, count, kbuf, ubuf, 0);
 658         if (ret)
 659                 return ret;
 660
 661         sve_sync_from_fpsimd_zeropad(target);
 662         fpsimd_flush_task_state(target);
 663
 664         return ret;
 665 }
 666
 667 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 668                    struct membuf to)
 669 {
 670         if (target == current)
 671                 tls_preserve_current_state();
 672
 673         return membuf_store(&to, target->thread.uw.tp_value);
 674 }
 675
 676 static int tls_set(struct task_struct *target, const struct user_regset *regset,
 677                    unsigned int pos, unsigned int count,
 678                    const void *kbuf, const void __user *ubuf)
 679 {
 680         int ret;
 681         unsigned long tls = target->thread.uw.tp_value;
 682
 683         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 684         if (ret)
 685                 return ret;
 686
 687         target->thread.uw.tp_value = tls;
 688         return ret;
 689 }
 690
 691 static int system_call_get(struct task_struct *target,
 692                            const struct user_regset *regset,
 693                            struct membuf to)
 694 {
 695         return membuf_store(&to, task_pt_regs(target)->syscallno);
 696 }
 697
 698 static int system_call_set(struct task_struct *target,
 699                            const struct user_regset *regset,
 700                            unsigned int pos, unsigned int count,
 701                            const void *kbuf, const void __user *ubuf)
 702 {
 703         int syscallno = task_pt_regs(target)->syscallno;
 704         int ret;
 705
 706         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &syscallno, 0, -1);
 707         if (ret)
 708                 return ret;
 709
 710         task_pt_regs(target)->syscallno = syscallno;
 711         return ret;
 712 }
 713
 714 #ifdef CONFIG_ARM64_SVE
 715
 716 static void sve_init_header_from_task(struct user_sve_header *header,
 717                                       struct task_struct *target)
 718 {
 719         unsigned int vq;
 720
 721         memset(header, 0, sizeof(*header));
 722
 723         header->flags = test_tsk_thread_flag(target, TIF_SVE) ?
 724                 SVE_PT_REGS_SVE : SVE_PT_REGS_FPSIMD;
 725         if (test_tsk_thread_flag(target, TIF_SVE_VL_INHERIT))
 726                 header->flags |= SVE_PT_VL_INHERIT;
 727
 728         header->vl = target->thread.sve_vl;
 729         vq = sve_vq_from_vl(header->vl);
 730
 731         header->max_vl = sve_max_vl;
 732         header->size = SVE_PT_SIZE(vq, header->flags);
 733         header->max_size = SVE_PT_SIZE(sve_vq_from_vl(header->max_vl),
 734                                       SVE_PT_REGS_SVE);
 735 }
 736
 737 static unsigned int sve_size_from_header(struct user_sve_header const *header)
 738 {
 739         return ALIGN(header->size, SVE_VQ_BYTES);
 740 }
 741
 742 static int sve_get(struct task_struct *target,
 743                    const struct user_regset *regset,
 744                    struct membuf to)
 745 {
 746         struct user_sve_header header;
 747         unsigned int vq;
 748         unsigned long start, end;
 749
 750         if (!system_supports_sve())
 751                 return -EINVAL;
 752
 753         /* Header */
 754         sve_init_header_from_task(&header, target);
 755         vq = sve_vq_from_vl(header.vl);
 756
 757         membuf_write(&to, &header, sizeof(header));
 758
 759         if (target == current)
 760                 fpsimd_preserve_current_state();
 761
 762         /* Registers: FPSIMD-only case */
 763
 764         BUILD_BUG_ON(SVE_PT_FPSIMD_OFFSET != sizeof(header));
 765         if ((header.flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD)
 766                 return __fpr_get(target, regset, to);
 767
 768         /* Otherwise: full SVE case */
 769
 770         BUILD_BUG_ON(SVE_PT_SVE_OFFSET != sizeof(header));
 771         start = SVE_PT_SVE_OFFSET;
 772         end = SVE_PT_SVE_FFR_OFFSET(vq) + SVE_PT_SVE_FFR_SIZE(vq);
 773         membuf_write(&to, target->thread.sve_state, end - start);
 774
 775         start = end;
 776         end = SVE_PT_SVE_FPSR_OFFSET(vq);
 777         membuf_zero(&to, end - start);
 778
 779         /*
 780          * Copy fpsr, and fpcr which must follow contiguously in
 781          * struct fpsimd_state:
 782          */
 783         start = end;
 784         end = SVE_PT_SVE_FPCR_OFFSET(vq) + SVE_PT_SVE_FPCR_SIZE;
 785         membuf_write(&to, &target->thread.uw.fpsimd_state.fpsr, end - start);
 786
 787         start = end;
 788         end = sve_size_from_header(&header);
 789         return membuf_zero(&to, end - start);
 790 }
 791
 792 static int sve_set(struct task_struct *target,
 793                    const struct user_regset *regset,
 794                    unsigned int pos, unsigned int count,
 795                    const void *kbuf, const void __user *ubuf)
 796 {
 797         int ret;
 798         struct user_sve_header header;
 799         unsigned int vq;
 800         unsigned long start, end;
 801
 802         if (!system_supports_sve())
 803                 return -EINVAL;
 804
 805         /* Header */
 806         if (count < sizeof(header))
 807                 return -EINVAL;
 808         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &header,
 809                                  0, sizeof(header));
 810         if (ret)
 811                 goto out;
 812
 813         /*
 814          * Apart from SVE_PT_REGS_MASK, all SVE_PT_* flags are consumed by
 815          * sve_set_vector_length(), which will also validate them for us:
 816          */
 817         ret = sve_set_vector_length(target, header.vl,
 818                 ((unsigned long)header.flags & ~SVE_PT_REGS_MASK) << 16);
 819         if (ret)
 820                 goto out;
 821
 822         /* Actual VL set may be less than the user asked for: */
 823         vq = sve_vq_from_vl(target->thread.sve_vl);
 824
 825         /* Registers: FPSIMD-only case */
 826
 827         BUILD_BUG_ON(SVE_PT_FPSIMD_OFFSET != sizeof(header));
 828         if ((header.flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD) {
 829                 ret = __fpr_set(target, regset, pos, count, kbuf, ubuf,
 830                                 SVE_PT_FPSIMD_OFFSET);
 831                 clear_tsk_thread_flag(target, TIF_SVE);
 832                 goto out;
 833         }
 834
 835         /* Otherwise: full SVE case */
 836
 837         /*
 838          * If setting a different VL from the requested VL and there is
 839          * register data, the data layout will be wrong: don't even
 840          * try to set the registers in this case.
 841          */
 842         if (count && vq != sve_vq_from_vl(header.vl)) {
 843                 ret = -EIO;
 844                 goto out;
 845         }
 846
 847         sve_alloc(target);
 848
 849         /*
 850          * Ensure target->thread.sve_state is up to date with target's
 851          * FPSIMD regs, so that a short copyin leaves trailing registers
 852          * unmodified.
 853          */
 854         fpsimd_sync_to_sve(target);
 855         set_tsk_thread_flag(target, TIF_SVE);
 856
 857         BUILD_BUG_ON(SVE_PT_SVE_OFFSET != sizeof(header));
 858         start = SVE_PT_SVE_OFFSET;
 859         end = SVE_PT_SVE_FFR_OFFSET(vq) + SVE_PT_SVE_FFR_SIZE(vq);
 860         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 861                                  target->thread.sve_state,
 862                                  start, end);
 863         if (ret)
 864                 goto out;
 865
 866         start = end;
 867         end = SVE_PT_SVE_FPSR_OFFSET(vq);
 868         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 869                                         start, end);
 870         if (ret)
 871                 goto out;
 872
 873         /*
 874          * Copy fpsr, and fpcr which must follow contiguously in
 875          * struct fpsimd_state:
 876          */
 877         start = end;
 878         end = SVE_PT_SVE_FPCR_OFFSET(vq) + SVE_PT_SVE_FPCR_SIZE;
 879         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 880                                  &target->thread.uw.fpsimd_state.fpsr,
 881                                  start, end);
 882
 883 out:
 884         fpsimd_flush_task_state(target);
 885         return ret;
 886 }
 887
 888 #endif /* CONFIG_ARM64_SVE */
 889
 890 #ifdef CONFIG_ARM64_PTR_AUTH
 891 static int pac_mask_get(struct task_struct *target,
 892                         const struct user_regset *regset,
 893                         struct membuf to)
 894 {
 895         /*
 896          * The PAC bits can differ across data and instruction pointers
 897          * depending on TCR_EL1.TBID*, which we may make use of in future, so
 898          * we expose separate masks.
 899          */
 900         unsigned long mask = ptrauth_user_pac_mask();
 901         struct user_pac_mask uregs = {
 902                 .data_mask = mask,
 903                 .insn_mask = mask,
 904         };
 905
 906         if (!system_supports_address_auth())
 907                 return -EINVAL;
 908
 909         return membuf_write(&to, &uregs, sizeof(uregs));
 910 }
 911
 912 #ifdef CONFIG_CHECKPOINT_RESTORE
 913 static __uint128_t pac_key_to_user(const struct ptrauth_key *key)
 914 {
 915         return (__uint128_t)key->hi << 64 | key->lo;
 916 }
 917
 918 static struct ptrauth_key pac_key_from_user(__uint128_t ukey)
 919 {
 920         struct ptrauth_key key = {
 921                 .lo = (unsigned long)ukey,
 922                 .hi = (unsigned long)(ukey >> 64),
 923         };
 924
 925         return key;
 926 }
 927
 928 static void pac_address_keys_to_user(struct user_pac_address_keys *ukeys,
 929                                      const struct ptrauth_keys_user *keys)
 930 {
 931         ukeys->apiakey = pac_key_to_user(&keys->apia);
 932         ukeys->apibkey = pac_key_to_user(&keys->apib);
 933         ukeys->apdakey = pac_key_to_user(&keys->apda);
 934         ukeys->apdbkey = pac_key_to_user(&keys->apdb);
 935 }
 936
 937 static void pac_address_keys_from_user(struct ptrauth_keys_user *keys,
 938                                        const struct user_pac_address_keys *ukeys)
 939 {
 940         keys->apia = pac_key_from_user(ukeys->apiakey);
 941         keys->apib = pac_key_from_user(ukeys->apibkey);
 942         keys->apda = pac_key_from_user(ukeys->apdakey);
 943         keys->apdb = pac_key_from_user(ukeys->apdbkey);
 944 }
 945
 946 static int pac_address_keys_get(struct task_struct *target,
 947                                 const struct user_regset *regset,
 948                                 struct membuf to)
 949 {
 950         struct ptrauth_keys_user *keys = &target->thread.keys_user;
 951         struct user_pac_address_keys user_keys;
 952
 953         if (!system_supports_address_auth())
 954                 return -EINVAL;
 955
 956         pac_address_keys_to_user(&user_keys, keys);
 957
 958         return membuf_write(&to, &user_keys, sizeof(user_keys));
 959 }
 960
 961 static int pac_address_keys_set(struct task_struct *target,
 962                                 const struct user_regset *regset,
 963                                 unsigned int pos, unsigned int count,
 964                                 const void *kbuf, const void __user *ubuf)
 965 {
 966         struct ptrauth_keys_user *keys = &target->thread.keys_user;
 967         struct user_pac_address_keys user_keys;
 968         int ret;
 969
 970         if (!system_supports_address_auth())
 971                 return -EINVAL;
 972
 973         pac_address_keys_to_user(&user_keys, keys);
 974         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 975                                  &user_keys, 0, -1);
 976         if (ret)
 977                 return ret;
 978         pac_address_keys_from_user(keys, &user_keys);
 979
 980         return 0;
 981 }
 982
 983 static void pac_generic_keys_to_user(struct user_pac_generic_keys *ukeys,
 984                                      const struct ptrauth_keys_user *keys)
 985 {
 986         ukeys->apgakey = pac_key_to_user(&keys->apga);
 987 }
 988
 989 static void pac_generic_keys_from_user(struct ptrauth_keys_user *keys,
 990                                        const struct user_pac_generic_keys *ukeys)
 991 {
 992         keys->apga = pac_key_from_user(ukeys->apgakey);
 993 }
 994
 995 static int pac_generic_keys_get(struct task_struct *target,
 996                                 const struct user_regset *regset,
 997                                 struct membuf to)
 998 {
 999         struct ptrauth_keys_user *keys = &target->thread.keys_user;
1000         struct user_pac_generic_keys user_keys;
1001
1002         if (!system_supports_generic_auth())
1003                 return -EINVAL;
1004
1005         pac_generic_keys_to_user(&user_keys, keys);
1006
1007         return membuf_write(&to, &user_keys, sizeof(user_keys));
1008 }
1009
1010 static int pac_generic_keys_set(struct task_struct *target,
1011                                 const struct user_regset *regset,
1012                                 unsigned int pos, unsigned int count,
1013                                 const void *kbuf, const void __user *ubuf)
1014 {
1015         struct ptrauth_keys_user *keys = &target->thread.keys_user;
1016         struct user_pac_generic_keys user_keys;
1017         int ret;
1018
1019         if (!system_supports_generic_auth())
1020                 return -EINVAL;
1021
1022         pac_generic_keys_to_user(&user_keys, keys);
1023         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1024                                  &user_keys, 0, -1);
1025         if (ret)
1026                 return ret;
1027         pac_generic_keys_from_user(keys, &user_keys);
1028
1029         return 0;
1030 }
1031 #endif /* CONFIG_CHECKPOINT_RESTORE */
1032 #endif /* CONFIG_ARM64_PTR_AUTH */
1033
1034 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
1035 static int tagged_addr_ctrl_get(struct task_struct *target,
1036                                 const struct user_regset *regset,
1037                                 struct membuf to)
1038 {
1039         long ctrl = get_tagged_addr_ctrl(target);
1040
1041         if (IS_ERR_VALUE(ctrl))
1042                 return ctrl;
1043
1044         return membuf_write(&to, &ctrl, sizeof(ctrl));
1045 }
1046
1047 static int tagged_addr_ctrl_set(struct task_struct *target, const struct
1048                                 user_regset *regset, unsigned int pos,
1049                                 unsigned int count, const void *kbuf, const
1050                                 void __user *ubuf)
1051 {
1052         int ret;
1053         long ctrl;
1054
1055         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl, 0, -1);
1056         if (ret)
1057                 return ret;
1058
1059         return set_tagged_addr_ctrl(target, ctrl);
1060 }
1061 #endif
1062
1063 enum aarch64_regset {
1064         REGSET_GPR,
1065         REGSET_FPR,
1066         REGSET_TLS,
1067 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1068         REGSET_HW_BREAK,
1069         REGSET_HW_WATCH,
1070 #endif
1071         REGSET_SYSTEM_CALL,
1072 #ifdef CONFIG_ARM64_SVE
1073         REGSET_SVE,
1074 #endif
1075 #ifdef CONFIG_ARM64_PTR_AUTH
1076         REGSET_PAC_MASK,
1077 #ifdef CONFIG_CHECKPOINT_RESTORE
1078         REGSET_PACA_KEYS,
1079         REGSET_PACG_KEYS,
1080 #endif
1081 #endif
1082 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
1083         REGSET_TAGGED_ADDR_CTRL,
1084 #endif
1085 };
1086
1087 static const struct user_regset aarch64_regsets[] = {
1088         [REGSET_GPR] = {
1089                 .core_note_type = NT_PRSTATUS,
1090                 .n = sizeof(struct user_pt_regs) / sizeof(u64),
1091                 .size = sizeof(u64),
1092                 .align = sizeof(u64),
1093                 .regset_get = gpr_get,
1094                 .set = gpr_set
1095         },
1096         [REGSET_FPR] = {
1097                 .core_note_type = NT_PRFPREG,
1098                 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
1099                 /*
1100                  * We pretend we have 32-bit registers because the fpsr and
1101                  * fpcr are 32-bits wide.
1102                  */
1103                 .size = sizeof(u32),
1104                 .align = sizeof(u32),
1105                 .active = fpr_active,
1106                 .regset_get = fpr_get,
1107                 .set = fpr_set
1108         },
1109         [REGSET_TLS] = {
1110                 .core_note_type = NT_ARM_TLS,
1111                 .n = 1,
1112                 .size = sizeof(void *),
1113                 .align = sizeof(void *),
1114                 .regset_get = tls_get,
1115                 .set = tls_set,
1116         },
1117 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1118         [REGSET_HW_BREAK] = {
1119                 .core_note_type = NT_ARM_HW_BREAK,
1120                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1121                 .size = sizeof(u32),
1122                 .align = sizeof(u32),
1123                 .regset_get = hw_break_get,
1124                 .set = hw_break_set,
1125         },
1126         [REGSET_HW_WATCH] = {
1127                 .core_note_type = NT_ARM_HW_WATCH,
1128                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1129                 .size = sizeof(u32),
1130                 .align = sizeof(u32),
1131                 .regset_get = hw_break_get,
1132                 .set = hw_break_set,
1133         },
1134 #endif
1135         [REGSET_SYSTEM_CALL] = {
1136                 .core_note_type = NT_ARM_SYSTEM_CALL,
1137                 .n = 1,
1138                 .size = sizeof(int),
1139                 .align = sizeof(int),
1140                 .regset_get = system_call_get,
1141                 .set = system_call_set,
1142         },
1143 #ifdef CONFIG_ARM64_SVE
1144         [REGSET_SVE] = { /* Scalable Vector Extension */
1145                 .core_note_type = NT_ARM_SVE,
1146                 .n = DIV_ROUND_UP(SVE_PT_SIZE(SVE_VQ_MAX, SVE_PT_REGS_SVE),
1147                                   SVE_VQ_BYTES),
1148                 .size = SVE_VQ_BYTES,
1149                 .align = SVE_VQ_BYTES,
1150                 .regset_get = sve_get,
1151                 .set = sve_set,
1152         },
1153 #endif
1154 #ifdef CONFIG_ARM64_PTR_AUTH
1155         [REGSET_PAC_MASK] = {
1156                 .core_note_type = NT_ARM_PAC_MASK,
1157                 .n = sizeof(struct user_pac_mask) / sizeof(u64),
1158                 .size = sizeof(u64),
1159                 .align = sizeof(u64),
1160                 .regset_get = pac_mask_get,
1161                 /* this cannot be set dynamically */
1162         },
1163 #ifdef CONFIG_CHECKPOINT_RESTORE
1164         [REGSET_PACA_KEYS] = {
1165                 .core_note_type = NT_ARM_PACA_KEYS,
1166                 .n = sizeof(struct user_pac_address_keys) / sizeof(__uint128_t),
1167                 .size = sizeof(__uint128_t),
1168                 .align = sizeof(__uint128_t),
1169                 .regset_get = pac_address_keys_get,
1170                 .set = pac_address_keys_set,
1171         },
1172         [REGSET_PACG_KEYS] = {
1173                 .core_note_type = NT_ARM_PACG_KEYS,
1174                 .n = sizeof(struct user_pac_generic_keys) / sizeof(__uint128_t),
1175                 .size = sizeof(__uint128_t),
1176                 .align = sizeof(__uint128_t),
1177                 .regset_get = pac_generic_keys_get,
1178                 .set = pac_generic_keys_set,
1179         },
1180 #endif
1181 #endif
1182 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
1183         [REGSET_TAGGED_ADDR_CTRL] = {
1184                 .core_note_type = NT_ARM_TAGGED_ADDR_CTRL,
1185                 .n = 1,
1186                 .size = sizeof(long),
1187                 .align = sizeof(long),
1188                 .regset_get = tagged_addr_ctrl_get,
1189                 .set = tagged_addr_ctrl_set,
1190         },
1191 #endif
1192 };
1193
1194 static const struct user_regset_view user_aarch64_view = {
1195         .name = "aarch64", .e_machine = EM_AARCH64,
1196         .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
1197 };
1198
1199 #ifdef CONFIG_COMPAT
1200 enum compat_regset {
1201         REGSET_COMPAT_GPR,
1202         REGSET_COMPAT_VFP,
1203 };
1204
1205 static inline compat_ulong_t compat_get_user_reg(struct task_struct *task, int idx)
1206 {
1207         struct pt_regs *regs = task_pt_regs(task);
1208
1209         switch (idx) {
1210         case 15:
1211                 return regs->pc;
1212         case 16:
1213                 return pstate_to_compat_psr(regs->pstate);
1214         case 17:
1215                 return regs->orig_x0;
1216         default:
1217                 return regs->regs[idx];
1218         }
1219 }
1220
1221 static int compat_gpr_get(struct task_struct *target,
1222                           const struct user_regset *regset,
1223                           struct membuf to)
1224 {
1225         int i = 0;
1226
1227         while (to.left)
1228                 membuf_store(&to, compat_get_user_reg(target, i++));
1229         return 0;
1230 }
1231
1232 static int compat_gpr_set(struct task_struct *target,
1233                           const struct user_regset *regset,
1234                           unsigned int pos, unsigned int count,
1235                           const void *kbuf, const void __user *ubuf)
1236 {
1237         struct pt_regs newregs;
1238         int ret = 0;
1239         unsigned int i, start, num_regs;
1240
1241         /* Calculate the number of AArch32 registers contained in count */
1242         num_regs = count / regset->size;
1243
1244         /* Convert pos into an register number */
1245         start = pos / regset->size;
1246
1247         if (start + num_regs > regset->n)
1248                 return -EIO;
1249
1250         newregs = *task_pt_regs(target);
1251
1252         for (i = 0; i < num_regs; ++i) {
1253                 unsigned int idx = start + i;
1254                 compat_ulong_t reg;
1255
1256                 if (kbuf) {
1257                         memcpy(&reg, kbuf, sizeof(reg));
1258                         kbuf += sizeof(reg);
1259                 } else {
1260                         ret = copy_from_user(&reg, ubuf, sizeof(reg));
1261                         if (ret) {
1262                                 ret = -EFAULT;
1263                                 break;
1264                         }
1265
1266                         ubuf += sizeof(reg);
1267                 }
1268
1269                 switch (idx) {
1270                 case 15:
1271                         newregs.pc = reg;
1272                         break;
1273                 case 16:
1274                         reg = compat_psr_to_pstate(reg);
1275                         newregs.pstate = reg;
1276                         break;
1277                 case 17:
1278                         newregs.orig_x0 = reg;
1279                         break;
1280                 default:
1281                         newregs.regs[idx] = reg;
1282                 }
1283
1284         }
1285
1286         if (valid_user_regs(&newregs.user_regs, target))
1287                 *task_pt_regs(target) = newregs;
1288         else
1289                 ret = -EINVAL;
1290
1291         return ret;
1292 }
1293
1294 static int compat_vfp_get(struct task_struct *target,
1295                           const struct user_regset *regset,
1296                           struct membuf to)
1297 {
1298         struct user_fpsimd_state *uregs;
1299         compat_ulong_t fpscr;
1300
1301         if (!system_supports_fpsimd())
1302                 return -EINVAL;
1303
1304         uregs = &target->thread.uw.fpsimd_state;
1305
1306         if (target == current)
1307                 fpsimd_preserve_current_state();
1308
1309         /*
1310          * The VFP registers are packed into the fpsimd_state, so they all sit
1311          * nicely together for us. We just need to create the fpscr separately.
1312          */
1313         membuf_write(&to, uregs, VFP_STATE_SIZE - sizeof(compat_ulong_t));
1314         fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
1315                 (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
1316         return membuf_store(&to, fpscr);
1317 }
1318
1319 static int compat_vfp_set(struct task_struct *target,
1320                           const struct user_regset *regset,
1321                           unsigned int pos, unsigned int count,
1322                           const void *kbuf, const void __user *ubuf)
1323 {
1324         struct user_fpsimd_state *uregs;
1325         compat_ulong_t fpscr;
1326         int ret, vregs_end_pos;
1327
1328         if (!system_supports_fpsimd())
1329                 return -EINVAL;
1330
1331         uregs = &target->thread.uw.fpsimd_state;
1332
1333         vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t);
1334         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
1335                                  vregs_end_pos);
1336
1337         if (count && !ret) {
1338                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpscr,
1339                                          vregs_end_pos, VFP_STATE_SIZE);
1340                 if (!ret) {
1341                         uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
1342                         uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
1343                 }
1344         }
1345
1346         fpsimd_flush_task_state(target);
1347         return ret;
1348 }
1349
1350 static int compat_tls_get(struct task_struct *target,
1351                           const struct user_regset *regset,
1352                           struct membuf to)
1353 {
1354         return membuf_store(&to, (compat_ulong_t)target->thread.uw.tp_value);
1355 }
1356
1357 static int compat_tls_set(struct task_struct *target,
1358                           const struct user_regset *regset, unsigned int pos,
1359                           unsigned int count, const void *kbuf,
1360                           const void __user *ubuf)
1361 {
1362         int ret;
1363         compat_ulong_t tls = target->thread.uw.tp_value;
1364
1365         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
1366         if (ret)
1367                 return ret;
1368
1369         target->thread.uw.tp_value = tls;
1370         return ret;
1371 }
1372
1373 static const struct user_regset aarch32_regsets[] = {
1374         [REGSET_COMPAT_GPR] = {
1375                 .core_note_type = NT_PRSTATUS,
1376                 .n = COMPAT_ELF_NGREG,
1377                 .size = sizeof(compat_elf_greg_t),
1378                 .align = sizeof(compat_elf_greg_t),
1379                 .regset_get = compat_gpr_get,
1380                 .set = compat_gpr_set
1381         },
1382         [REGSET_COMPAT_VFP] = {
1383                 .core_note_type = NT_ARM_VFP,
1384                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
1385                 .size = sizeof(compat_ulong_t),
1386                 .align = sizeof(compat_ulong_t),
1387                 .active = fpr_active,
1388                 .regset_get = compat_vfp_get,
1389                 .set = compat_vfp_set
1390         },
1391 };
1392
1393 static const struct user_regset_view user_aarch32_view = {
1394         .name = "aarch32", .e_machine = EM_ARM,
1395         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
1396 };
1397
1398 static const struct user_regset aarch32_ptrace_regsets[] = {
1399         [REGSET_GPR] = {
1400                 .core_note_type = NT_PRSTATUS,
1401                 .n = COMPAT_ELF_NGREG,
1402                 .size = sizeof(compat_elf_greg_t),
1403                 .align = sizeof(compat_elf_greg_t),
1404                 .regset_get = compat_gpr_get,
1405                 .set = compat_gpr_set
1406         },
1407         [REGSET_FPR] = {
1408                 .core_note_type = NT_ARM_VFP,
1409                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
1410                 .size = sizeof(compat_ulong_t),
1411                 .align = sizeof(compat_ulong_t),
1412                 .regset_get = compat_vfp_get,
1413                 .set = compat_vfp_set
1414         },
1415         [REGSET_TLS] = {
1416                 .core_note_type = NT_ARM_TLS,
1417                 .n = 1,
1418                 .size = sizeof(compat_ulong_t),
1419                 .align = sizeof(compat_ulong_t),
1420                 .regset_get = compat_tls_get,
1421                 .set = compat_tls_set,
1422         },
1423 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1424         [REGSET_HW_BREAK] = {
1425                 .core_note_type = NT_ARM_HW_BREAK,
1426                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1427                 .size = sizeof(u32),
1428                 .align = sizeof(u32),
1429                 .regset_get = hw_break_get,
1430                 .set = hw_break_set,
1431         },
1432         [REGSET_HW_WATCH] = {
1433                 .core_note_type = NT_ARM_HW_WATCH,
1434                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1435                 .size = sizeof(u32),
1436                 .align = sizeof(u32),
1437                 .regset_get = hw_break_get,
1438                 .set = hw_break_set,
1439         },
1440 #endif
1441         [REGSET_SYSTEM_CALL] = {
1442                 .core_note_type = NT_ARM_SYSTEM_CALL,
1443                 .n = 1,
1444                 .size = sizeof(int),
1445                 .align = sizeof(int),
1446                 .regset_get = system_call_get,
1447                 .set = system_call_set,
1448         },
1449 };
1450
1451 static const struct user_regset_view user_aarch32_ptrace_view = {
1452         .name = "aarch32", .e_machine = EM_ARM,
1453         .regsets = aarch32_ptrace_regsets, .n = ARRAY_SIZE(aarch32_ptrace_regsets)
1454 };
1455
1456 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
1457                                    compat_ulong_t __user *ret)
1458 {
1459         compat_ulong_t tmp;
1460
1461         if (off & 3)
1462                 return -EIO;
1463
1464         if (off == COMPAT_PT_TEXT_ADDR)
1465                 tmp = tsk->mm->start_code;
1466         else if (off == COMPAT_PT_DATA_ADDR)
1467                 tmp = tsk->mm->start_data;
1468         else if (off == COMPAT_PT_TEXT_END_ADDR)
1469                 tmp = tsk->mm->end_code;
1470         else if (off < sizeof(compat_elf_gregset_t))
1471                 tmp = compat_get_user_reg(tsk, off >> 2);
1472         else if (off >= COMPAT_USER_SZ)
1473                 return -EIO;
1474         else
1475                 tmp = 0;
1476
1477         return put_user(tmp, ret);
1478 }
1479
1480 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
1481                                     compat_ulong_t val)
1482 {
1483         struct pt_regs newregs = *task_pt_regs(tsk);
1484         unsigned int idx = off / 4;
1485
1486         if (off & 3 || off >= COMPAT_USER_SZ)
1487                 return -EIO;
1488
1489         if (off >= sizeof(compat_elf_gregset_t))
1490                 return 0;
1491
1492         switch (idx) {
1493         case 15:
1494                 newregs.pc = val;
1495                 break;
1496         case 16:
1497                 newregs.pstate = compat_psr_to_pstate(val);
1498                 break;
1499         case 17:
1500                 newregs.orig_x0 = val;
1501                 break;
1502         default:
1503                 newregs.regs[idx] = val;
1504         }
1505
1506         if (!valid_user_regs(&newregs.user_regs, tsk))
1507                 return -EINVAL;
1508
1509         *task_pt_regs(tsk) = newregs;
1510         return 0;
1511 }
1512
1513 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1514
1515 /*
1516  * Convert a virtual register number into an index for a thread_info
1517  * breakpoint array. Breakpoints are identified using positive numbers
1518  * whilst watchpoints are negative. The registers are laid out as pairs
1519  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
1520  * Register 0 is reserved for describing resource information.
1521  */
1522 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
1523 {
1524         return (abs(num) - 1) >> 1;
1525 }
1526
1527 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
1528 {
1529         u8 num_brps, num_wrps, debug_arch, wp_len;
1530         u32 reg = 0;
1531
1532         num_brps        = hw_breakpoint_slots(TYPE_INST);
1533         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
1534
1535         debug_arch      = debug_monitors_arch();
1536         wp_len          = 8;
1537         reg             |= debug_arch;
1538         reg             <<= 8;
1539         reg             |= wp_len;
1540         reg             <<= 8;
1541         reg             |= num_wrps;
1542         reg             <<= 8;
1543         reg             |= num_brps;
1544
1545         *kdata = reg;
1546         return 0;
1547 }
1548
1549 static int compat_ptrace_hbp_get(unsigned int note_type,
1550                                  struct task_struct *tsk,
1551                                  compat_long_t num,
1552                                  u32 *kdata)
1553 {
1554         u64 addr = 0;
1555         u32 ctrl = 0;
1556
1557         int err, idx = compat_ptrace_hbp_num_to_idx(num);
1558
1559         if (num & 1) {
1560                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
1561                 *kdata = (u32)addr;
1562         } else {
1563                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
1564                 *kdata = ctrl;
1565         }
1566
1567         return err;
1568 }
1569
1570 static int compat_ptrace_hbp_set(unsigned int note_type,
1571                                  struct task_struct *tsk,
1572                                  compat_long_t num,
1573                                  u32 *kdata)
1574 {
1575         u64 addr;
1576         u32 ctrl;
1577
1578         int err, idx = compat_ptrace_hbp_num_to_idx(num);
1579
1580         if (num & 1) {
1581                 addr = *kdata;
1582                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
1583         } else {
1584                 ctrl = *kdata;
1585                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
1586         }
1587
1588         return err;
1589 }
1590
1591 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
1592                                     compat_ulong_t __user *data)
1593 {
1594         int ret;
1595         u32 kdata;
1596
1597         /* Watchpoint */
1598         if (num < 0) {
1599                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
1600         /* Resource info */
1601         } else if (num == 0) {
1602                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
1603         /* Breakpoint */
1604         } else {
1605                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
1606         }
1607
1608         if (!ret)
1609                 ret = put_user(kdata, data);
1610
1611         return ret;
1612 }
1613
1614 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
1615                                     compat_ulong_t __user *data)
1616 {
1617         int ret;
1618         u32 kdata = 0;
1619
1620         if (num == 0)
1621                 return 0;
1622
1623         ret = get_user(kdata, data);
1624         if (ret)
1625                 return ret;
1626
1627         if (num < 0)
1628                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
1629         else
1630                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
1631
1632         return ret;
1633 }
1634 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
1635
1636 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1637                         compat_ulong_t caddr, compat_ulong_t cdata)
1638 {
1639         unsigned long addr = caddr;
1640         unsigned long data = cdata;
1641         void __user *datap = compat_ptr(data);
1642         int ret;
1643
1644         switch (request) {
1645                 case PTRACE_PEEKUSR:
1646                         ret = compat_ptrace_read_user(child, addr, datap);
1647                         break;
1648
1649                 case PTRACE_POKEUSR:
1650                         ret = compat_ptrace_write_user(child, addr, data);
1651                         break;
1652
1653                 case COMPAT_PTRACE_GETREGS:
1654                         ret = copy_regset_to_user(child,
1655                                                   &user_aarch32_view,
1656                                                   REGSET_COMPAT_GPR,
1657                                                   0, sizeof(compat_elf_gregset_t),
1658                                                   datap);
1659                         break;
1660
1661                 case COMPAT_PTRACE_SETREGS:
1662                         ret = copy_regset_from_user(child,
1663                                                     &user_aarch32_view,
1664                                                     REGSET_COMPAT_GPR,
1665                                                     0, sizeof(compat_elf_gregset_t),
1666                                                     datap);
1667                         break;
1668
1669                 case COMPAT_PTRACE_GET_THREAD_AREA:
1670                         ret = put_user((compat_ulong_t)child->thread.uw.tp_value,
1671                                        (compat_ulong_t __user *)datap);
1672                         break;
1673
1674                 case COMPAT_PTRACE_SET_SYSCALL:
1675                         task_pt_regs(child)->syscallno = data;
1676                         ret = 0;
1677                         break;
1678
1679                 case COMPAT_PTRACE_GETVFPREGS:
1680                         ret = copy_regset_to_user(child,
1681                                                   &user_aarch32_view,
1682                                                   REGSET_COMPAT_VFP,
1683                                                   0, VFP_STATE_SIZE,
1684                                                   datap);
1685                         break;
1686
1687                 case COMPAT_PTRACE_SETVFPREGS:
1688                         ret = copy_regset_from_user(child,
1689                                                     &user_aarch32_view,
1690                                                     REGSET_COMPAT_VFP,
1691                                                     0, VFP_STATE_SIZE,
1692                                                     datap);
1693                         break;
1694
1695 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1696                 case COMPAT_PTRACE_GETHBPREGS:
1697                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1698                         break;
1699
1700                 case COMPAT_PTRACE_SETHBPREGS:
1701                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1702                         break;
1703 #endif
1704
1705                 default:
1706                         ret = compat_ptrace_request(child, request, addr,
1707                                                     data);
1708                         break;
1709         }
1710
1711         return ret;
1712 }
1713 #endif /* CONFIG_COMPAT */
1714
1715 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1716 {
1717 #ifdef CONFIG_COMPAT
1718         /*
1719          * Core dumping of 32-bit tasks or compat ptrace requests must use the
1720          * user_aarch32_view compatible with arm32. Native ptrace requests on
1721          * 32-bit children use an extended user_aarch32_ptrace_view to allow
1722          * access to the TLS register.
1723          */
1724         if (is_compat_task())
1725                 return &user_aarch32_view;
1726         else if (is_compat_thread(task_thread_info(task)))
1727                 return &user_aarch32_ptrace_view;
1728 #endif
1729         return &user_aarch64_view;
1730 }
1731
1732 long arch_ptrace(struct task_struct *child, long request,
1733                  unsigned long addr, unsigned long data)
1734 {
1735         switch (request) {
1736         case PTRACE_PEEKMTETAGS:
1737         case PTRACE_POKEMTETAGS:
1738                 return mte_ptrace_copy_tags(child, request, addr, data);
1739         }
1740
1741         return ptrace_request(child, request, addr, data);
1742 }
1743
1744 enum ptrace_syscall_dir {
1745         PTRACE_SYSCALL_ENTER = 0,
1746         PTRACE_SYSCALL_EXIT,
1747 };
1748
1749 static void tracehook_report_syscall(struct pt_regs *regs,
1750                                      enum ptrace_syscall_dir dir)
1751 {
1752         int regno;
1753         unsigned long saved_reg;
1754
1755         /*
1756          * We have some ABI weirdness here in the way that we handle syscall
1757          * exit stops because we indicate whether or not the stop has been
1758          * signalled from syscall entry or syscall exit by clobbering a general
1759          * purpose register (ip/r12 for AArch32, x7 for AArch64) in the tracee
1760          * and restoring its old value after the stop. This means that:
1761          *
1762          * - Any writes by the tracer to this register during the stop are
1763          *   ignored/discarded.
1764          *
1765          * - The actual value of the register is not available during the stop,
1766          *   so the tracer cannot save it and restore it later.
1767          *
1768          * - Syscall stops behave differently to seccomp and pseudo-step traps
1769          *   (the latter do not nobble any registers).
1770          */
1771         regno = (is_compat_task() ? 12 : 7);
1772         saved_reg = regs->regs[regno];
1773         regs->regs[regno] = dir;
1774
1775         if (dir == PTRACE_SYSCALL_ENTER) {
1776                 if (tracehook_report_syscall_entry(regs))
1777                         forget_syscall(regs);
1778                 regs->regs[regno] = saved_reg;
1779         } else if (!test_thread_flag(TIF_SINGLESTEP)) {
1780                 tracehook_report_syscall_exit(regs, 0);
1781                 regs->regs[regno] = saved_reg;
1782         } else {
1783                 regs->regs[regno] = saved_reg;
1784
1785                 /*
1786                  * Signal a pseudo-step exception since we are stepping but
1787                  * tracer modifications to the registers may have rewound the
1788                  * state machine.
1789                  */
1790                 tracehook_report_syscall_exit(regs, 1);
1791         }
1792 }
1793
1794 int syscall_trace_enter(struct pt_regs *regs)
1795 {
1796         unsigned long flags = READ_ONCE(current_thread_info()->flags);
1797
1798         if (flags & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE)) {
1799                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1800                 if (!in_syscall(regs) || (flags & _TIF_SYSCALL_EMU))
1801                         return NO_SYSCALL;
1802         }
1803
1804         /* Do the secure computing after ptrace; failures should be fast. */
1805         if (secure_computing() == -1)
1806                 return NO_SYSCALL;
1807
1808         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1809                 trace_sys_enter(regs, regs->syscallno);
1810
1811         audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1],
1812                             regs->regs[2], regs->regs[3]);
1813
1814         return regs->syscallno;
1815 }
1816
1817 void syscall_trace_exit(struct pt_regs *regs)
1818 {
1819         unsigned long flags = READ_ONCE(current_thread_info()->flags);
1820
1821         audit_syscall_exit(regs);
1822
1823         if (flags & _TIF_SYSCALL_TRACEPOINT)
1824                 trace_sys_exit(regs, regs_return_value(regs));
1825
1826         if (flags & (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP))
1827                 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1828
1829         rseq_syscall(regs);
1830 }
1831
1832 /*
1833  * SPSR_ELx bits which are always architecturally RES0 per ARM DDI 0487D.a.
1834  * We permit userspace to set SSBS (AArch64 bit 12, AArch32 bit 23) which is
1835  * not described in ARM DDI 0487D.a.
1836  * We treat PAN and UAO as RES0 bits, as they are meaningless at EL0, and may
1837  * be allocated an EL0 meaning in future.
1838  * Userspace cannot use these until they have an architectural meaning.
1839  * Note that this follows the SPSR_ELx format, not the AArch32 PSR format.
1840  * We also reserve IL for the kernel; SS is handled dynamically.
1841  */
1842 #define SPSR_EL1_AARCH64_RES0_BITS \
1843         (GENMASK_ULL(63, 32) | GENMASK_ULL(27, 26) | GENMASK_ULL(23, 22) | \
1844          GENMASK_ULL(20, 13) | GENMASK_ULL(5, 5))
1845 #define SPSR_EL1_AARCH32_RES0_BITS \
1846         (GENMASK_ULL(63, 32) | GENMASK_ULL(22, 22) | GENMASK_ULL(20, 20))
1847
1848 static int valid_compat_regs(struct user_pt_regs *regs)
1849 {
1850         regs->pstate &= ~SPSR_EL1_AARCH32_RES0_BITS;
1851
1852         if (!system_supports_mixed_endian_el0()) {
1853                 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
1854                         regs->pstate |= PSR_AA32_E_BIT;
1855                 else
1856                         regs->pstate &= ~PSR_AA32_E_BIT;
1857         }
1858
1859         if (user_mode(regs) && (regs->pstate & PSR_MODE32_BIT) &&
1860             (regs->pstate & PSR_AA32_A_BIT) == 0 &&
1861             (regs->pstate & PSR_AA32_I_BIT) == 0 &&
1862             (regs->pstate & PSR_AA32_F_BIT) == 0) {
1863                 return 1;
1864         }
1865
1866         /*
1867          * Force PSR to a valid 32-bit EL0t, preserving the same bits as
1868          * arch/arm.
1869          */
1870         regs->pstate &= PSR_AA32_N_BIT | PSR_AA32_Z_BIT |
1871                         PSR_AA32_C_BIT | PSR_AA32_V_BIT |
1872                         PSR_AA32_Q_BIT | PSR_AA32_IT_MASK |
1873                         PSR_AA32_GE_MASK | PSR_AA32_E_BIT |
1874                         PSR_AA32_T_BIT;
1875         regs->pstate |= PSR_MODE32_BIT;
1876
1877         return 0;
1878 }
1879
1880 static int valid_native_regs(struct user_pt_regs *regs)
1881 {
1882         regs->pstate &= ~SPSR_EL1_AARCH64_RES0_BITS;
1883
1884         if (user_mode(regs) && !(regs->pstate & PSR_MODE32_BIT) &&
1885             (regs->pstate & PSR_D_BIT) == 0 &&
1886             (regs->pstate & PSR_A_BIT) == 0 &&
1887             (regs->pstate & PSR_I_BIT) == 0 &&
1888             (regs->pstate & PSR_F_BIT) == 0) {
1889                 return 1;
1890         }
1891
1892         /* Force PSR to a valid 64-bit EL0t */
1893         regs->pstate &= PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT;
1894
1895         return 0;
1896 }
1897
1898 /*
1899  * Are the current registers suitable for user mode? (used to maintain
1900  * security in signal handlers)
1901  */
1902 int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task)
1903 {
1904         /* https://lore.kernel.org/lkml/20191118131525.GA4180@willie-the-truck */
1905         user_regs_reset_single_step(regs, task);
1906
1907         if (is_compat_thread(task_thread_info(task)))
1908                 return valid_compat_regs(regs);
1909         else
1910                 return valid_native_regs(regs);
1911 }