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, sizeof(unsigned long), 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 static int pac_enabled_keys_get(struct task_struct *target,
 913                                 const struct user_regset *regset,
 914                                 struct membuf to)
 915 {
 916         long enabled_keys = ptrauth_get_enabled_keys(target);
 917
 918         if (IS_ERR_VALUE(enabled_keys))
 919                 return enabled_keys;
 920
 921         return membuf_write(&to, &enabled_keys, sizeof(enabled_keys));
 922 }
 923
 924 static int pac_enabled_keys_set(struct task_struct *target,
 925                                 const struct user_regset *regset,
 926                                 unsigned int pos, unsigned int count,
 927                                 const void *kbuf, const void __user *ubuf)
 928 {
 929         int ret;
 930         long enabled_keys = ptrauth_get_enabled_keys(target);
 931
 932         if (IS_ERR_VALUE(enabled_keys))
 933                 return enabled_keys;
 934
 935         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &enabled_keys, 0,
 936                                  sizeof(long));
 937         if (ret)
 938                 return ret;
 939
 940         return ptrauth_set_enabled_keys(target, PR_PAC_ENABLED_KEYS_MASK,
 941                                         enabled_keys);
 942 }
 943
 944 #ifdef CONFIG_CHECKPOINT_RESTORE
 945 static __uint128_t pac_key_to_user(const struct ptrauth_key *key)
 946 {
 947         return (__uint128_t)key->hi << 64 | key->lo;
 948 }
 949
 950 static struct ptrauth_key pac_key_from_user(__uint128_t ukey)
 951 {
 952         struct ptrauth_key key = {
 953                 .lo = (unsigned long)ukey,
 954                 .hi = (unsigned long)(ukey >> 64),
 955         };
 956
 957         return key;
 958 }
 959
 960 static void pac_address_keys_to_user(struct user_pac_address_keys *ukeys,
 961                                      const struct ptrauth_keys_user *keys)
 962 {
 963         ukeys->apiakey = pac_key_to_user(&keys->apia);
 964         ukeys->apibkey = pac_key_to_user(&keys->apib);
 965         ukeys->apdakey = pac_key_to_user(&keys->apda);
 966         ukeys->apdbkey = pac_key_to_user(&keys->apdb);
 967 }
 968
 969 static void pac_address_keys_from_user(struct ptrauth_keys_user *keys,
 970                                        const struct user_pac_address_keys *ukeys)
 971 {
 972         keys->apia = pac_key_from_user(ukeys->apiakey);
 973         keys->apib = pac_key_from_user(ukeys->apibkey);
 974         keys->apda = pac_key_from_user(ukeys->apdakey);
 975         keys->apdb = pac_key_from_user(ukeys->apdbkey);
 976 }
 977
 978 static int pac_address_keys_get(struct task_struct *target,
 979                                 const struct user_regset *regset,
 980                                 struct membuf to)
 981 {
 982         struct ptrauth_keys_user *keys = &target->thread.keys_user;
 983         struct user_pac_address_keys user_keys;
 984
 985         if (!system_supports_address_auth())
 986                 return -EINVAL;
 987
 988         pac_address_keys_to_user(&user_keys, keys);
 989
 990         return membuf_write(&to, &user_keys, sizeof(user_keys));
 991 }
 992
 993 static int pac_address_keys_set(struct task_struct *target,
 994                                 const struct user_regset *regset,
 995                                 unsigned int pos, unsigned int count,
 996                                 const void *kbuf, const void __user *ubuf)
 997 {
 998         struct ptrauth_keys_user *keys = &target->thread.keys_user;
 999         struct user_pac_address_keys user_keys;
1000         int ret;
1001
1002         if (!system_supports_address_auth())
1003                 return -EINVAL;
1004
1005         pac_address_keys_to_user(&user_keys, keys);
1006         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1007                                  &user_keys, 0, -1);
1008         if (ret)
1009                 return ret;
1010         pac_address_keys_from_user(keys, &user_keys);
1011
1012         return 0;
1013 }
1014
1015 static void pac_generic_keys_to_user(struct user_pac_generic_keys *ukeys,
1016                                      const struct ptrauth_keys_user *keys)
1017 {
1018         ukeys->apgakey = pac_key_to_user(&keys->apga);
1019 }
1020
1021 static void pac_generic_keys_from_user(struct ptrauth_keys_user *keys,
1022                                        const struct user_pac_generic_keys *ukeys)
1023 {
1024         keys->apga = pac_key_from_user(ukeys->apgakey);
1025 }
1026
1027 static int pac_generic_keys_get(struct task_struct *target,
1028                                 const struct user_regset *regset,
1029                                 struct membuf to)
1030 {
1031         struct ptrauth_keys_user *keys = &target->thread.keys_user;
1032         struct user_pac_generic_keys user_keys;
1033
1034         if (!system_supports_generic_auth())
1035                 return -EINVAL;
1036
1037         pac_generic_keys_to_user(&user_keys, keys);
1038
1039         return membuf_write(&to, &user_keys, sizeof(user_keys));
1040 }
1041
1042 static int pac_generic_keys_set(struct task_struct *target,
1043                                 const struct user_regset *regset,
1044                                 unsigned int pos, unsigned int count,
1045                                 const void *kbuf, const void __user *ubuf)
1046 {
1047         struct ptrauth_keys_user *keys = &target->thread.keys_user;
1048         struct user_pac_generic_keys user_keys;
1049         int ret;
1050
1051         if (!system_supports_generic_auth())
1052                 return -EINVAL;
1053
1054         pac_generic_keys_to_user(&user_keys, keys);
1055         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1056                                  &user_keys, 0, -1);
1057         if (ret)
1058                 return ret;
1059         pac_generic_keys_from_user(keys, &user_keys);
1060
1061         return 0;
1062 }
1063 #endif /* CONFIG_CHECKPOINT_RESTORE */
1064 #endif /* CONFIG_ARM64_PTR_AUTH */
1065
1066 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
1067 static int tagged_addr_ctrl_get(struct task_struct *target,
1068                                 const struct user_regset *regset,
1069                                 struct membuf to)
1070 {
1071         long ctrl = get_tagged_addr_ctrl(target);
1072
1073         if (IS_ERR_VALUE(ctrl))
1074                 return ctrl;
1075
1076         return membuf_write(&to, &ctrl, sizeof(ctrl));
1077 }
1078
1079 static int tagged_addr_ctrl_set(struct task_struct *target, const struct
1080                                 user_regset *regset, unsigned int pos,
1081                                 unsigned int count, const void *kbuf, const
1082                                 void __user *ubuf)
1083 {
1084         int ret;
1085         long ctrl;
1086
1087         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl, 0, -1);
1088         if (ret)
1089                 return ret;
1090
1091         return set_tagged_addr_ctrl(target, ctrl);
1092 }
1093 #endif
1094
1095 enum aarch64_regset {
1096         REGSET_GPR,
1097         REGSET_FPR,
1098         REGSET_TLS,
1099 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1100         REGSET_HW_BREAK,
1101         REGSET_HW_WATCH,
1102 #endif
1103         REGSET_SYSTEM_CALL,
1104 #ifdef CONFIG_ARM64_SVE
1105         REGSET_SVE,
1106 #endif
1107 #ifdef CONFIG_ARM64_PTR_AUTH
1108         REGSET_PAC_MASK,
1109         REGSET_PAC_ENABLED_KEYS,
1110 #ifdef CONFIG_CHECKPOINT_RESTORE
1111         REGSET_PACA_KEYS,
1112         REGSET_PACG_KEYS,
1113 #endif
1114 #endif
1115 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
1116         REGSET_TAGGED_ADDR_CTRL,
1117 #endif
1118 };
1119
1120 static const struct user_regset aarch64_regsets[] = {
1121         [REGSET_GPR] = {
1122                 .core_note_type = NT_PRSTATUS,
1123                 .n = sizeof(struct user_pt_regs) / sizeof(u64),
1124                 .size = sizeof(u64),
1125                 .align = sizeof(u64),
1126                 .regset_get = gpr_get,
1127                 .set = gpr_set
1128         },
1129         [REGSET_FPR] = {
1130                 .core_note_type = NT_PRFPREG,
1131                 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
1132                 /*
1133                  * We pretend we have 32-bit registers because the fpsr and
1134                  * fpcr are 32-bits wide.
1135                  */
1136                 .size = sizeof(u32),
1137                 .align = sizeof(u32),
1138                 .active = fpr_active,
1139                 .regset_get = fpr_get,
1140                 .set = fpr_set
1141         },
1142         [REGSET_TLS] = {
1143                 .core_note_type = NT_ARM_TLS,
1144                 .n = 1,
1145                 .size = sizeof(void *),
1146                 .align = sizeof(void *),
1147                 .regset_get = tls_get,
1148                 .set = tls_set,
1149         },
1150 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1151         [REGSET_HW_BREAK] = {
1152                 .core_note_type = NT_ARM_HW_BREAK,
1153                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1154                 .size = sizeof(u32),
1155                 .align = sizeof(u32),
1156                 .regset_get = hw_break_get,
1157                 .set = hw_break_set,
1158         },
1159         [REGSET_HW_WATCH] = {
1160                 .core_note_type = NT_ARM_HW_WATCH,
1161                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1162                 .size = sizeof(u32),
1163                 .align = sizeof(u32),
1164                 .regset_get = hw_break_get,
1165                 .set = hw_break_set,
1166         },
1167 #endif
1168         [REGSET_SYSTEM_CALL] = {
1169                 .core_note_type = NT_ARM_SYSTEM_CALL,
1170                 .n = 1,
1171                 .size = sizeof(int),
1172                 .align = sizeof(int),
1173                 .regset_get = system_call_get,
1174                 .set = system_call_set,
1175         },
1176 #ifdef CONFIG_ARM64_SVE
1177         [REGSET_SVE] = { /* Scalable Vector Extension */
1178                 .core_note_type = NT_ARM_SVE,
1179                 .n = DIV_ROUND_UP(SVE_PT_SIZE(SVE_VQ_MAX, SVE_PT_REGS_SVE),
1180                                   SVE_VQ_BYTES),
1181                 .size = SVE_VQ_BYTES,
1182                 .align = SVE_VQ_BYTES,
1183                 .regset_get = sve_get,
1184                 .set = sve_set,
1185         },
1186 #endif
1187 #ifdef CONFIG_ARM64_PTR_AUTH
1188         [REGSET_PAC_MASK] = {
1189                 .core_note_type = NT_ARM_PAC_MASK,
1190                 .n = sizeof(struct user_pac_mask) / sizeof(u64),
1191                 .size = sizeof(u64),
1192                 .align = sizeof(u64),
1193                 .regset_get = pac_mask_get,
1194                 /* this cannot be set dynamically */
1195         },
1196         [REGSET_PAC_ENABLED_KEYS] = {
1197                 .core_note_type = NT_ARM_PAC_ENABLED_KEYS,
1198                 .n = 1,
1199                 .size = sizeof(long),
1200                 .align = sizeof(long),
1201                 .regset_get = pac_enabled_keys_get,
1202                 .set = pac_enabled_keys_set,
1203         },
1204 #ifdef CONFIG_CHECKPOINT_RESTORE
1205         [REGSET_PACA_KEYS] = {
1206                 .core_note_type = NT_ARM_PACA_KEYS,
1207                 .n = sizeof(struct user_pac_address_keys) / sizeof(__uint128_t),
1208                 .size = sizeof(__uint128_t),
1209                 .align = sizeof(__uint128_t),
1210                 .regset_get = pac_address_keys_get,
1211                 .set = pac_address_keys_set,
1212         },
1213         [REGSET_PACG_KEYS] = {
1214                 .core_note_type = NT_ARM_PACG_KEYS,
1215                 .n = sizeof(struct user_pac_generic_keys) / sizeof(__uint128_t),
1216                 .size = sizeof(__uint128_t),
1217                 .align = sizeof(__uint128_t),
1218                 .regset_get = pac_generic_keys_get,
1219                 .set = pac_generic_keys_set,
1220         },
1221 #endif
1222 #endif
1223 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
1224         [REGSET_TAGGED_ADDR_CTRL] = {
1225                 .core_note_type = NT_ARM_TAGGED_ADDR_CTRL,
1226                 .n = 1,
1227                 .size = sizeof(long),
1228                 .align = sizeof(long),
1229                 .regset_get = tagged_addr_ctrl_get,
1230                 .set = tagged_addr_ctrl_set,
1231         },
1232 #endif
1233 };
1234
1235 static const struct user_regset_view user_aarch64_view = {
1236         .name = "aarch64", .e_machine = EM_AARCH64,
1237         .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
1238 };
1239
1240 #ifdef CONFIG_COMPAT
1241 enum compat_regset {
1242         REGSET_COMPAT_GPR,
1243         REGSET_COMPAT_VFP,
1244 };
1245
1246 static inline compat_ulong_t compat_get_user_reg(struct task_struct *task, int idx)
1247 {
1248         struct pt_regs *regs = task_pt_regs(task);
1249
1250         switch (idx) {
1251         case 15:
1252                 return regs->pc;
1253         case 16:
1254                 return pstate_to_compat_psr(regs->pstate);
1255         case 17:
1256                 return regs->orig_x0;
1257         default:
1258                 return regs->regs[idx];
1259         }
1260 }
1261
1262 static int compat_gpr_get(struct task_struct *target,
1263                           const struct user_regset *regset,
1264                           struct membuf to)
1265 {
1266         int i = 0;
1267
1268         while (to.left)
1269                 membuf_store(&to, compat_get_user_reg(target, i++));
1270         return 0;
1271 }
1272
1273 static int compat_gpr_set(struct task_struct *target,
1274                           const struct user_regset *regset,
1275                           unsigned int pos, unsigned int count,
1276                           const void *kbuf, const void __user *ubuf)
1277 {
1278         struct pt_regs newregs;
1279         int ret = 0;
1280         unsigned int i, start, num_regs;
1281
1282         /* Calculate the number of AArch32 registers contained in count */
1283         num_regs = count / regset->size;
1284
1285         /* Convert pos into an register number */
1286         start = pos / regset->size;
1287
1288         if (start + num_regs > regset->n)
1289                 return -EIO;
1290
1291         newregs = *task_pt_regs(target);
1292
1293         for (i = 0; i < num_regs; ++i) {
1294                 unsigned int idx = start + i;
1295                 compat_ulong_t reg;
1296
1297                 if (kbuf) {
1298                         memcpy(&reg, kbuf, sizeof(reg));
1299                         kbuf += sizeof(reg);
1300                 } else {
1301                         ret = copy_from_user(&reg, ubuf, sizeof(reg));
1302                         if (ret) {
1303                                 ret = -EFAULT;
1304                                 break;
1305                         }
1306
1307                         ubuf += sizeof(reg);
1308                 }
1309
1310                 switch (idx) {
1311                 case 15:
1312                         newregs.pc = reg;
1313                         break;
1314                 case 16:
1315                         reg = compat_psr_to_pstate(reg);
1316                         newregs.pstate = reg;
1317                         break;
1318                 case 17:
1319                         newregs.orig_x0 = reg;
1320                         break;
1321                 default:
1322                         newregs.regs[idx] = reg;
1323                 }
1324
1325         }
1326
1327         if (valid_user_regs(&newregs.user_regs, target))
1328                 *task_pt_regs(target) = newregs;
1329         else
1330                 ret = -EINVAL;
1331
1332         return ret;
1333 }
1334
1335 static int compat_vfp_get(struct task_struct *target,
1336                           const struct user_regset *regset,
1337                           struct membuf to)
1338 {
1339         struct user_fpsimd_state *uregs;
1340         compat_ulong_t fpscr;
1341
1342         if (!system_supports_fpsimd())
1343                 return -EINVAL;
1344
1345         uregs = &target->thread.uw.fpsimd_state;
1346
1347         if (target == current)
1348                 fpsimd_preserve_current_state();
1349
1350         /*
1351          * The VFP registers are packed into the fpsimd_state, so they all sit
1352          * nicely together for us. We just need to create the fpscr separately.
1353          */
1354         membuf_write(&to, uregs, VFP_STATE_SIZE - sizeof(compat_ulong_t));
1355         fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
1356                 (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
1357         return membuf_store(&to, fpscr);
1358 }
1359
1360 static int compat_vfp_set(struct task_struct *target,
1361                           const struct user_regset *regset,
1362                           unsigned int pos, unsigned int count,
1363                           const void *kbuf, const void __user *ubuf)
1364 {
1365         struct user_fpsimd_state *uregs;
1366         compat_ulong_t fpscr;
1367         int ret, vregs_end_pos;
1368
1369         if (!system_supports_fpsimd())
1370                 return -EINVAL;
1371
1372         uregs = &target->thread.uw.fpsimd_state;
1373
1374         vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t);
1375         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
1376                                  vregs_end_pos);
1377
1378         if (count && !ret) {
1379                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpscr,
1380                                          vregs_end_pos, VFP_STATE_SIZE);
1381                 if (!ret) {
1382                         uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
1383                         uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
1384                 }
1385         }
1386
1387         fpsimd_flush_task_state(target);
1388         return ret;
1389 }
1390
1391 static int compat_tls_get(struct task_struct *target,
1392                           const struct user_regset *regset,
1393                           struct membuf to)
1394 {
1395         return membuf_store(&to, (compat_ulong_t)target->thread.uw.tp_value);
1396 }
1397
1398 static int compat_tls_set(struct task_struct *target,
1399                           const struct user_regset *regset, unsigned int pos,
1400                           unsigned int count, const void *kbuf,
1401                           const void __user *ubuf)
1402 {
1403         int ret;
1404         compat_ulong_t tls = target->thread.uw.tp_value;
1405
1406         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
1407         if (ret)
1408                 return ret;
1409
1410         target->thread.uw.tp_value = tls;
1411         return ret;
1412 }
1413
1414 static const struct user_regset aarch32_regsets[] = {
1415         [REGSET_COMPAT_GPR] = {
1416                 .core_note_type = NT_PRSTATUS,
1417                 .n = COMPAT_ELF_NGREG,
1418                 .size = sizeof(compat_elf_greg_t),
1419                 .align = sizeof(compat_elf_greg_t),
1420                 .regset_get = compat_gpr_get,
1421                 .set = compat_gpr_set
1422         },
1423         [REGSET_COMPAT_VFP] = {
1424                 .core_note_type = NT_ARM_VFP,
1425                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
1426                 .size = sizeof(compat_ulong_t),
1427                 .align = sizeof(compat_ulong_t),
1428                 .active = fpr_active,
1429                 .regset_get = compat_vfp_get,
1430                 .set = compat_vfp_set
1431         },
1432 };
1433
1434 static const struct user_regset_view user_aarch32_view = {
1435         .name = "aarch32", .e_machine = EM_ARM,
1436         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
1437 };
1438
1439 static const struct user_regset aarch32_ptrace_regsets[] = {
1440         [REGSET_GPR] = {
1441                 .core_note_type = NT_PRSTATUS,
1442                 .n = COMPAT_ELF_NGREG,
1443                 .size = sizeof(compat_elf_greg_t),
1444                 .align = sizeof(compat_elf_greg_t),
1445                 .regset_get = compat_gpr_get,
1446                 .set = compat_gpr_set
1447         },
1448         [REGSET_FPR] = {
1449                 .core_note_type = NT_ARM_VFP,
1450                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
1451                 .size = sizeof(compat_ulong_t),
1452                 .align = sizeof(compat_ulong_t),
1453                 .regset_get = compat_vfp_get,
1454                 .set = compat_vfp_set
1455         },
1456         [REGSET_TLS] = {
1457                 .core_note_type = NT_ARM_TLS,
1458                 .n = 1,
1459                 .size = sizeof(compat_ulong_t),
1460                 .align = sizeof(compat_ulong_t),
1461                 .regset_get = compat_tls_get,
1462                 .set = compat_tls_set,
1463         },
1464 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1465         [REGSET_HW_BREAK] = {
1466                 .core_note_type = NT_ARM_HW_BREAK,
1467                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1468                 .size = sizeof(u32),
1469                 .align = sizeof(u32),
1470                 .regset_get = hw_break_get,
1471                 .set = hw_break_set,
1472         },
1473         [REGSET_HW_WATCH] = {
1474                 .core_note_type = NT_ARM_HW_WATCH,
1475                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1476                 .size = sizeof(u32),
1477                 .align = sizeof(u32),
1478                 .regset_get = hw_break_get,
1479                 .set = hw_break_set,
1480         },
1481 #endif
1482         [REGSET_SYSTEM_CALL] = {
1483                 .core_note_type = NT_ARM_SYSTEM_CALL,
1484                 .n = 1,
1485                 .size = sizeof(int),
1486                 .align = sizeof(int),
1487                 .regset_get = system_call_get,
1488                 .set = system_call_set,
1489         },
1490 };
1491
1492 static const struct user_regset_view user_aarch32_ptrace_view = {
1493         .name = "aarch32", .e_machine = EM_ARM,
1494         .regsets = aarch32_ptrace_regsets, .n = ARRAY_SIZE(aarch32_ptrace_regsets)
1495 };
1496
1497 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
1498                                    compat_ulong_t __user *ret)
1499 {
1500         compat_ulong_t tmp;
1501
1502         if (off & 3)
1503                 return -EIO;
1504
1505         if (off == COMPAT_PT_TEXT_ADDR)
1506                 tmp = tsk->mm->start_code;
1507         else if (off == COMPAT_PT_DATA_ADDR)
1508                 tmp = tsk->mm->start_data;
1509         else if (off == COMPAT_PT_TEXT_END_ADDR)
1510                 tmp = tsk->mm->end_code;
1511         else if (off < sizeof(compat_elf_gregset_t))
1512                 tmp = compat_get_user_reg(tsk, off >> 2);
1513         else if (off >= COMPAT_USER_SZ)
1514                 return -EIO;
1515         else
1516                 tmp = 0;
1517
1518         return put_user(tmp, ret);
1519 }
1520
1521 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
1522                                     compat_ulong_t val)
1523 {
1524         struct pt_regs newregs = *task_pt_regs(tsk);
1525         unsigned int idx = off / 4;
1526
1527         if (off & 3 || off >= COMPAT_USER_SZ)
1528                 return -EIO;
1529
1530         if (off >= sizeof(compat_elf_gregset_t))
1531                 return 0;
1532
1533         switch (idx) {
1534         case 15:
1535                 newregs.pc = val;
1536                 break;
1537         case 16:
1538                 newregs.pstate = compat_psr_to_pstate(val);
1539                 break;
1540         case 17:
1541                 newregs.orig_x0 = val;
1542                 break;
1543         default:
1544                 newregs.regs[idx] = val;
1545         }
1546
1547         if (!valid_user_regs(&newregs.user_regs, tsk))
1548                 return -EINVAL;
1549
1550         *task_pt_regs(tsk) = newregs;
1551         return 0;
1552 }
1553
1554 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1555
1556 /*
1557  * Convert a virtual register number into an index for a thread_info
1558  * breakpoint array. Breakpoints are identified using positive numbers
1559  * whilst watchpoints are negative. The registers are laid out as pairs
1560  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
1561  * Register 0 is reserved for describing resource information.
1562  */
1563 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
1564 {
1565         return (abs(num) - 1) >> 1;
1566 }
1567
1568 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
1569 {
1570         u8 num_brps, num_wrps, debug_arch, wp_len;
1571         u32 reg = 0;
1572
1573         num_brps        = hw_breakpoint_slots(TYPE_INST);
1574         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
1575
1576         debug_arch      = debug_monitors_arch();
1577         wp_len          = 8;
1578         reg             |= debug_arch;
1579         reg             <<= 8;
1580         reg             |= wp_len;
1581         reg             <<= 8;
1582         reg             |= num_wrps;
1583         reg             <<= 8;
1584         reg             |= num_brps;
1585
1586         *kdata = reg;
1587         return 0;
1588 }
1589
1590 static int compat_ptrace_hbp_get(unsigned int note_type,
1591                                  struct task_struct *tsk,
1592                                  compat_long_t num,
1593                                  u32 *kdata)
1594 {
1595         u64 addr = 0;
1596         u32 ctrl = 0;
1597
1598         int err, idx = compat_ptrace_hbp_num_to_idx(num);
1599
1600         if (num & 1) {
1601                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
1602                 *kdata = (u32)addr;
1603         } else {
1604                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
1605                 *kdata = ctrl;
1606         }
1607
1608         return err;
1609 }
1610
1611 static int compat_ptrace_hbp_set(unsigned int note_type,
1612                                  struct task_struct *tsk,
1613                                  compat_long_t num,
1614                                  u32 *kdata)
1615 {
1616         u64 addr;
1617         u32 ctrl;
1618
1619         int err, idx = compat_ptrace_hbp_num_to_idx(num);
1620
1621         if (num & 1) {
1622                 addr = *kdata;
1623                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
1624         } else {
1625                 ctrl = *kdata;
1626                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
1627         }
1628
1629         return err;
1630 }
1631
1632 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
1633                                     compat_ulong_t __user *data)
1634 {
1635         int ret;
1636         u32 kdata;
1637
1638         /* Watchpoint */
1639         if (num < 0) {
1640                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
1641         /* Resource info */
1642         } else if (num == 0) {
1643                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
1644         /* Breakpoint */
1645         } else {
1646                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
1647         }
1648
1649         if (!ret)
1650                 ret = put_user(kdata, data);
1651
1652         return ret;
1653 }
1654
1655 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
1656                                     compat_ulong_t __user *data)
1657 {
1658         int ret;
1659         u32 kdata = 0;
1660
1661         if (num == 0)
1662                 return 0;
1663
1664         ret = get_user(kdata, data);
1665         if (ret)
1666                 return ret;
1667
1668         if (num < 0)
1669                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
1670         else
1671                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
1672
1673         return ret;
1674 }
1675 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
1676
1677 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1678                         compat_ulong_t caddr, compat_ulong_t cdata)
1679 {
1680         unsigned long addr = caddr;
1681         unsigned long data = cdata;
1682         void __user *datap = compat_ptr(data);
1683         int ret;
1684
1685         switch (request) {
1686                 case PTRACE_PEEKUSR:
1687                         ret = compat_ptrace_read_user(child, addr, datap);
1688                         break;
1689
1690                 case PTRACE_POKEUSR:
1691                         ret = compat_ptrace_write_user(child, addr, data);
1692                         break;
1693
1694                 case COMPAT_PTRACE_GETREGS:
1695                         ret = copy_regset_to_user(child,
1696                                                   &user_aarch32_view,
1697                                                   REGSET_COMPAT_GPR,
1698                                                   0, sizeof(compat_elf_gregset_t),
1699                                                   datap);
1700                         break;
1701
1702                 case COMPAT_PTRACE_SETREGS:
1703                         ret = copy_regset_from_user(child,
1704                                                     &user_aarch32_view,
1705                                                     REGSET_COMPAT_GPR,
1706                                                     0, sizeof(compat_elf_gregset_t),
1707                                                     datap);
1708                         break;
1709
1710                 case COMPAT_PTRACE_GET_THREAD_AREA:
1711                         ret = put_user((compat_ulong_t)child->thread.uw.tp_value,
1712                                        (compat_ulong_t __user *)datap);
1713                         break;
1714
1715                 case COMPAT_PTRACE_SET_SYSCALL:
1716                         task_pt_regs(child)->syscallno = data;
1717                         ret = 0;
1718                         break;
1719
1720                 case COMPAT_PTRACE_GETVFPREGS:
1721                         ret = copy_regset_to_user(child,
1722                                                   &user_aarch32_view,
1723                                                   REGSET_COMPAT_VFP,
1724                                                   0, VFP_STATE_SIZE,
1725                                                   datap);
1726                         break;
1727
1728                 case COMPAT_PTRACE_SETVFPREGS:
1729                         ret = copy_regset_from_user(child,
1730                                                     &user_aarch32_view,
1731                                                     REGSET_COMPAT_VFP,
1732                                                     0, VFP_STATE_SIZE,
1733                                                     datap);
1734                         break;
1735
1736 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1737                 case COMPAT_PTRACE_GETHBPREGS:
1738                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1739                         break;
1740
1741                 case COMPAT_PTRACE_SETHBPREGS:
1742                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1743                         break;
1744 #endif
1745
1746                 default:
1747                         ret = compat_ptrace_request(child, request, addr,
1748                                                     data);
1749                         break;
1750         }
1751
1752         return ret;
1753 }
1754 #endif /* CONFIG_COMPAT */
1755
1756 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1757 {
1758 #ifdef CONFIG_COMPAT
1759         /*
1760          * Core dumping of 32-bit tasks or compat ptrace requests must use the
1761          * user_aarch32_view compatible with arm32. Native ptrace requests on
1762          * 32-bit children use an extended user_aarch32_ptrace_view to allow
1763          * access to the TLS register.
1764          */
1765         if (is_compat_task())
1766                 return &user_aarch32_view;
1767         else if (is_compat_thread(task_thread_info(task)))
1768                 return &user_aarch32_ptrace_view;
1769 #endif
1770         return &user_aarch64_view;
1771 }
1772
1773 long arch_ptrace(struct task_struct *child, long request,
1774                  unsigned long addr, unsigned long data)
1775 {
1776         switch (request) {
1777         case PTRACE_PEEKMTETAGS:
1778         case PTRACE_POKEMTETAGS:
1779                 return mte_ptrace_copy_tags(child, request, addr, data);
1780         }
1781
1782         return ptrace_request(child, request, addr, data);
1783 }
1784
1785 enum ptrace_syscall_dir {
1786         PTRACE_SYSCALL_ENTER = 0,
1787         PTRACE_SYSCALL_EXIT,
1788 };
1789
1790 static void tracehook_report_syscall(struct pt_regs *regs,
1791                                      enum ptrace_syscall_dir dir)
1792 {
1793         int regno;
1794         unsigned long saved_reg;
1795
1796         /*
1797          * We have some ABI weirdness here in the way that we handle syscall
1798          * exit stops because we indicate whether or not the stop has been
1799          * signalled from syscall entry or syscall exit by clobbering a general
1800          * purpose register (ip/r12 for AArch32, x7 for AArch64) in the tracee
1801          * and restoring its old value after the stop. This means that:
1802          *
1803          * - Any writes by the tracer to this register during the stop are
1804          *   ignored/discarded.
1805          *
1806          * - The actual value of the register is not available during the stop,
1807          *   so the tracer cannot save it and restore it later.
1808          *
1809          * - Syscall stops behave differently to seccomp and pseudo-step traps
1810          *   (the latter do not nobble any registers).
1811          */
1812         regno = (is_compat_task() ? 12 : 7);
1813         saved_reg = regs->regs[regno];
1814         regs->regs[regno] = dir;
1815
1816         if (dir == PTRACE_SYSCALL_ENTER) {
1817                 if (tracehook_report_syscall_entry(regs))
1818                         forget_syscall(regs);
1819                 regs->regs[regno] = saved_reg;
1820         } else if (!test_thread_flag(TIF_SINGLESTEP)) {
1821                 tracehook_report_syscall_exit(regs, 0);
1822                 regs->regs[regno] = saved_reg;
1823         } else {
1824                 regs->regs[regno] = saved_reg;
1825
1826                 /*
1827                  * Signal a pseudo-step exception since we are stepping but
1828                  * tracer modifications to the registers may have rewound the
1829                  * state machine.
1830                  */
1831                 tracehook_report_syscall_exit(regs, 1);
1832         }
1833 }
1834
1835 int syscall_trace_enter(struct pt_regs *regs)
1836 {
1837         unsigned long flags = READ_ONCE(current_thread_info()->flags);
1838
1839         if (flags & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE)) {
1840                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1841                 if (flags & _TIF_SYSCALL_EMU)
1842                         return NO_SYSCALL;
1843         }
1844
1845         /* Do the secure computing after ptrace; failures should be fast. */
1846         if (secure_computing() == -1)
1847                 return NO_SYSCALL;
1848
1849         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1850                 trace_sys_enter(regs, regs->syscallno);
1851
1852         audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1],
1853                             regs->regs[2], regs->regs[3]);
1854
1855         return regs->syscallno;
1856 }
1857
1858 void syscall_trace_exit(struct pt_regs *regs)
1859 {
1860         unsigned long flags = READ_ONCE(current_thread_info()->flags);
1861
1862         audit_syscall_exit(regs);
1863
1864         if (flags & _TIF_SYSCALL_TRACEPOINT)
1865                 trace_sys_exit(regs, regs_return_value(regs));
1866
1867         if (flags & (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP))
1868                 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1869
1870         rseq_syscall(regs);
1871 }
1872
1873 /*
1874  * SPSR_ELx bits which are always architecturally RES0 per ARM DDI 0487D.a.
1875  * We permit userspace to set SSBS (AArch64 bit 12, AArch32 bit 23) which is
1876  * not described in ARM DDI 0487D.a.
1877  * We treat PAN and UAO as RES0 bits, as they are meaningless at EL0, and may
1878  * be allocated an EL0 meaning in future.
1879  * Userspace cannot use these until they have an architectural meaning.
1880  * Note that this follows the SPSR_ELx format, not the AArch32 PSR format.
1881  * We also reserve IL for the kernel; SS is handled dynamically.
1882  */
1883 #define SPSR_EL1_AARCH64_RES0_BITS \
1884         (GENMASK_ULL(63, 32) | GENMASK_ULL(27, 26) | GENMASK_ULL(23, 22) | \
1885          GENMASK_ULL(20, 13) | GENMASK_ULL(5, 5))
1886 #define SPSR_EL1_AARCH32_RES0_BITS \
1887         (GENMASK_ULL(63, 32) | GENMASK_ULL(22, 22) | GENMASK_ULL(20, 20))
1888
1889 static int valid_compat_regs(struct user_pt_regs *regs)
1890 {
1891         regs->pstate &= ~SPSR_EL1_AARCH32_RES0_BITS;
1892
1893         if (!system_supports_mixed_endian_el0()) {
1894                 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
1895                         regs->pstate |= PSR_AA32_E_BIT;
1896                 else
1897                         regs->pstate &= ~PSR_AA32_E_BIT;
1898         }
1899
1900         if (user_mode(regs) && (regs->pstate & PSR_MODE32_BIT) &&
1901             (regs->pstate & PSR_AA32_A_BIT) == 0 &&
1902             (regs->pstate & PSR_AA32_I_BIT) == 0 &&
1903             (regs->pstate & PSR_AA32_F_BIT) == 0) {
1904                 return 1;
1905         }
1906
1907         /*
1908          * Force PSR to a valid 32-bit EL0t, preserving the same bits as
1909          * arch/arm.
1910          */
1911         regs->pstate &= PSR_AA32_N_BIT | PSR_AA32_Z_BIT |
1912                         PSR_AA32_C_BIT | PSR_AA32_V_BIT |
1913                         PSR_AA32_Q_BIT | PSR_AA32_IT_MASK |
1914                         PSR_AA32_GE_MASK | PSR_AA32_E_BIT |
1915                         PSR_AA32_T_BIT;
1916         regs->pstate |= PSR_MODE32_BIT;
1917
1918         return 0;
1919 }
1920
1921 static int valid_native_regs(struct user_pt_regs *regs)
1922 {
1923         regs->pstate &= ~SPSR_EL1_AARCH64_RES0_BITS;
1924
1925         if (user_mode(regs) && !(regs->pstate & PSR_MODE32_BIT) &&
1926             (regs->pstate & PSR_D_BIT) == 0 &&
1927             (regs->pstate & PSR_A_BIT) == 0 &&
1928             (regs->pstate & PSR_I_BIT) == 0 &&
1929             (regs->pstate & PSR_F_BIT) == 0) {
1930                 return 1;
1931         }
1932
1933         /* Force PSR to a valid 64-bit EL0t */
1934         regs->pstate &= PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT;
1935
1936         return 0;
1937 }
1938
1939 /*
1940  * Are the current registers suitable for user mode? (used to maintain
1941  * security in signal handlers)
1942  */
1943 int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task)
1944 {
1945         /* https://lore.kernel.org/lkml/20191118131525.GA4180@willie-the-truck */
1946         user_regs_reset_single_step(regs, task);
1947
1948         if (is_compat_thread(task_thread_info(task)))
1949                 return valid_compat_regs(regs);
1950         else
1951                 return valid_native_regs(regs);
1952 }