arch/arm64/kernel/ptrace.c

   1 /*
   2  * Based on arch/arm/kernel/ptrace.c
   3  *
   4  * By Ross Biro 1/23/92
   5  * edited by Linus Torvalds
   6  * ARM modifications Copyright (C) 2000 Russell King
   7  * Copyright (C) 2012 ARM Ltd.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <linux/audit.h>
  23 #include <linux/compat.h>
  24 #include <linux/kernel.h>
  25 #include <linux/sched/signal.h>
  26 #include <linux/sched/task_stack.h>
  27 #include <linux/mm.h>
  28 #include <linux/nospec.h>
  29 #include <linux/smp.h>
  30 #include <linux/ptrace.h>
  31 #include <linux/user.h>
  32 #include <linux/seccomp.h>
  33 #include <linux/security.h>
  34 #include <linux/init.h>
  35 #include <linux/signal.h>
  36 #include <linux/string.h>
  37 #include <linux/uaccess.h>
  38 #include <linux/perf_event.h>
  39 #include <linux/hw_breakpoint.h>
  40 #include <linux/regset.h>
  41 #include <linux/tracehook.h>
  42 #include <linux/elf.h>
  43
  44 #include <asm/compat.h>
  45 #include <asm/cpufeature.h>
  46 #include <asm/debug-monitors.h>
  47 #include <asm/pgtable.h>
  48 #include <asm/stacktrace.h>
  49 #include <asm/syscall.h>
  50 #include <asm/traps.h>
  51 #include <asm/system_misc.h>
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/syscalls.h>
  55
  56 struct pt_regs_offset {
  57         const char *name;
  58         int offset;
  59 };
  60
  61 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  62 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  63 #define GPR_OFFSET_NAME(r) \
  64         {.name = "x" #r, .offset = offsetof(struct pt_regs, regs[r])}
  65
  66 static const struct pt_regs_offset regoffset_table[] = {
  67         GPR_OFFSET_NAME(0),
  68         GPR_OFFSET_NAME(1),
  69         GPR_OFFSET_NAME(2),
  70         GPR_OFFSET_NAME(3),
  71         GPR_OFFSET_NAME(4),
  72         GPR_OFFSET_NAME(5),
  73         GPR_OFFSET_NAME(6),
  74         GPR_OFFSET_NAME(7),
  75         GPR_OFFSET_NAME(8),
  76         GPR_OFFSET_NAME(9),
  77         GPR_OFFSET_NAME(10),
  78         GPR_OFFSET_NAME(11),
  79         GPR_OFFSET_NAME(12),
  80         GPR_OFFSET_NAME(13),
  81         GPR_OFFSET_NAME(14),
  82         GPR_OFFSET_NAME(15),
  83         GPR_OFFSET_NAME(16),
  84         GPR_OFFSET_NAME(17),
  85         GPR_OFFSET_NAME(18),
  86         GPR_OFFSET_NAME(19),
  87         GPR_OFFSET_NAME(20),
  88         GPR_OFFSET_NAME(21),
  89         GPR_OFFSET_NAME(22),
  90         GPR_OFFSET_NAME(23),
  91         GPR_OFFSET_NAME(24),
  92         GPR_OFFSET_NAME(25),
  93         GPR_OFFSET_NAME(26),
  94         GPR_OFFSET_NAME(27),
  95         GPR_OFFSET_NAME(28),
  96         GPR_OFFSET_NAME(29),
  97         GPR_OFFSET_NAME(30),
  98         {.name = "lr", .offset = offsetof(struct pt_regs, regs[30])},
  99         REG_OFFSET_NAME(sp),
 100         REG_OFFSET_NAME(pc),
 101         REG_OFFSET_NAME(pstate),
 102         REG_OFFSET_END,
 103 };
 104
 105 /**
 106  * regs_query_register_offset() - query register offset from its name
 107  * @name:       the name of a register
 108  *
 109  * regs_query_register_offset() returns the offset of a register in struct
 110  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 111  */
 112 int regs_query_register_offset(const char *name)
 113 {
 114         const struct pt_regs_offset *roff;
 115
 116         for (roff = regoffset_table; roff->name != NULL; roff++)
 117                 if (!strcmp(roff->name, name))
 118                         return roff->offset;
 119         return -EINVAL;
 120 }
 121
 122 /**
 123  * regs_within_kernel_stack() - check the address in the stack
 124  * @regs:      pt_regs which contains kernel stack pointer.
 125  * @addr:      address which is checked.
 126  *
 127  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 128  * If @addr is within the kernel stack, it returns true. If not, returns false.
 129  */
 130 static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 131 {
 132         return ((addr & ~(THREAD_SIZE - 1))  ==
 133                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))) ||
 134                 on_irq_stack(addr);
 135 }
 136
 137 /**
 138  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 139  * @regs:       pt_regs which contains kernel stack pointer.
 140  * @n:          stack entry number.
 141  *
 142  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 143  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 144  * this returns 0.
 145  */
 146 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 147 {
 148         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 149
 150         addr += n;
 151         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 152                 return *addr;
 153         else
 154                 return 0;
 155 }
 156
 157 /*
 158  * TODO: does not yet catch signals sent when the child dies.
 159  * in exit.c or in signal.c.
 160  */
 161
 162 /*
 163  * Called by kernel/ptrace.c when detaching..
 164  */
 165 void ptrace_disable(struct task_struct *child)
 166 {
 167         /*
 168          * This would be better off in core code, but PTRACE_DETACH has
 169          * grown its fair share of arch-specific worts and changing it
 170          * is likely to cause regressions on obscure architectures.
 171          */
 172         user_disable_single_step(child);
 173 }
 174
 175 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 176 /*
 177  * Handle hitting a HW-breakpoint.
 178  */
 179 static void ptrace_hbptriggered(struct perf_event *bp,
 180                                 struct perf_sample_data *data,
 181                                 struct pt_regs *regs)
 182 {
 183         struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
 184         siginfo_t info;
 185
 186         clear_siginfo(&info);
 187         info.si_signo   = SIGTRAP;
 188         info.si_errno   = 0;
 189         info.si_code    = TRAP_HWBKPT;
 190         info.si_addr    = (void __user *)(bkpt->trigger);
 191
 192 #ifdef CONFIG_COMPAT
 193         if (is_compat_task()) {
 194                 int si_errno = 0;
 195                 int i;
 196
 197                 for (i = 0; i < ARM_MAX_BRP; ++i) {
 198                         if (current->thread.debug.hbp_break[i] == bp) {
 199                                 si_errno = (i << 1) + 1;
 200                                 break;
 201                         }
 202                 }
 203
 204                 for (i = 0; i < ARM_MAX_WRP; ++i) {
 205                         if (current->thread.debug.hbp_watch[i] == bp) {
 206                                 si_errno = -((i << 1) + 1);
 207                                 break;
 208                         }
 209                 }
 210                 force_sig_ptrace_errno_trap(si_errno, (void __user *)bkpt->trigger);
 211         }
 212 #endif
 213         arm64_force_sig_info(&info, "Hardware breakpoint trap (ptrace)", current);
 214 }
 215
 216 /*
 217  * Unregister breakpoints from this task and reset the pointers in
 218  * the thread_struct.
 219  */
 220 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 221 {
 222         int i;
 223         struct thread_struct *t = &tsk->thread;
 224
 225         for (i = 0; i < ARM_MAX_BRP; i++) {
 226                 if (t->debug.hbp_break[i]) {
 227                         unregister_hw_breakpoint(t->debug.hbp_break[i]);
 228                         t->debug.hbp_break[i] = NULL;
 229                 }
 230         }
 231
 232         for (i = 0; i < ARM_MAX_WRP; i++) {
 233                 if (t->debug.hbp_watch[i]) {
 234                         unregister_hw_breakpoint(t->debug.hbp_watch[i]);
 235                         t->debug.hbp_watch[i] = NULL;
 236                 }
 237         }
 238 }
 239
 240 void ptrace_hw_copy_thread(struct task_struct *tsk)
 241 {
 242         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 243 }
 244
 245 static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
 246                                                struct task_struct *tsk,
 247                                                unsigned long idx)
 248 {
 249         struct perf_event *bp = ERR_PTR(-EINVAL);
 250
 251         switch (note_type) {
 252         case NT_ARM_HW_BREAK:
 253                 if (idx >= ARM_MAX_BRP)
 254                         goto out;
 255                 idx = array_index_nospec(idx, ARM_MAX_BRP);
 256                 bp = tsk->thread.debug.hbp_break[idx];
 257                 break;
 258         case NT_ARM_HW_WATCH:
 259                 if (idx >= ARM_MAX_WRP)
 260                         goto out;
 261                 idx = array_index_nospec(idx, ARM_MAX_WRP);
 262                 bp = tsk->thread.debug.hbp_watch[idx];
 263                 break;
 264         }
 265
 266 out:
 267         return bp;
 268 }
 269
 270 static int ptrace_hbp_set_event(unsigned int note_type,
 271                                 struct task_struct *tsk,
 272                                 unsigned long idx,
 273                                 struct perf_event *bp)
 274 {
 275         int err = -EINVAL;
 276
 277         switch (note_type) {
 278         case NT_ARM_HW_BREAK:
 279                 if (idx < ARM_MAX_BRP) {
 280                         tsk->thread.debug.hbp_break[idx] = bp;
 281                         err = 0;
 282                 }
 283                 break;
 284         case NT_ARM_HW_WATCH:
 285                 if (idx < ARM_MAX_WRP) {
 286                         tsk->thread.debug.hbp_watch[idx] = bp;
 287                         err = 0;
 288                 }
 289                 break;
 290         }
 291
 292         return err;
 293 }
 294
 295 static struct perf_event *ptrace_hbp_create(unsigned int note_type,
 296                                             struct task_struct *tsk,
 297                                             unsigned long idx)
 298 {
 299         struct perf_event *bp;
 300         struct perf_event_attr attr;
 301         int err, type;
 302
 303         switch (note_type) {
 304         case NT_ARM_HW_BREAK:
 305                 type = HW_BREAKPOINT_X;
 306                 break;
 307         case NT_ARM_HW_WATCH:
 308                 type = HW_BREAKPOINT_RW;
 309                 break;
 310         default:
 311                 return ERR_PTR(-EINVAL);
 312         }
 313
 314         ptrace_breakpoint_init(&attr);
 315
 316         /*
 317          * Initialise fields to sane defaults
 318          * (i.e. values that will pass validation).
 319          */
 320         attr.bp_addr    = 0;
 321         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 322         attr.bp_type    = type;
 323         attr.disabled   = 1;
 324
 325         bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk);
 326         if (IS_ERR(bp))
 327                 return bp;
 328
 329         err = ptrace_hbp_set_event(note_type, tsk, idx, bp);
 330         if (err)
 331                 return ERR_PTR(err);
 332
 333         return bp;
 334 }
 335
 336 static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
 337                                      struct arch_hw_breakpoint_ctrl ctrl,
 338                                      struct perf_event_attr *attr)
 339 {
 340         int err, len, type, offset, disabled = !ctrl.enabled;
 341
 342         attr->disabled = disabled;
 343         if (disabled)
 344                 return 0;
 345
 346         err = arch_bp_generic_fields(ctrl, &len, &type, &offset);
 347         if (err)
 348                 return err;
 349
 350         switch (note_type) {
 351         case NT_ARM_HW_BREAK:
 352                 if ((type & HW_BREAKPOINT_X) != type)
 353                         return -EINVAL;
 354                 break;
 355         case NT_ARM_HW_WATCH:
 356                 if ((type & HW_BREAKPOINT_RW) != type)
 357                         return -EINVAL;
 358                 break;
 359         default:
 360                 return -EINVAL;
 361         }
 362
 363         attr->bp_len    = len;
 364         attr->bp_type   = type;
 365         attr->bp_addr   += offset;
 366
 367         return 0;
 368 }
 369
 370 static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info)
 371 {
 372         u8 num;
 373         u32 reg = 0;
 374
 375         switch (note_type) {
 376         case NT_ARM_HW_BREAK:
 377                 num = hw_breakpoint_slots(TYPE_INST);
 378                 break;
 379         case NT_ARM_HW_WATCH:
 380                 num = hw_breakpoint_slots(TYPE_DATA);
 381                 break;
 382         default:
 383                 return -EINVAL;
 384         }
 385
 386         reg |= debug_monitors_arch();
 387         reg <<= 8;
 388         reg |= num;
 389
 390         *info = reg;
 391         return 0;
 392 }
 393
 394 static int ptrace_hbp_get_ctrl(unsigned int note_type,
 395                                struct task_struct *tsk,
 396                                unsigned long idx,
 397                                u32 *ctrl)
 398 {
 399         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 400
 401         if (IS_ERR(bp))
 402                 return PTR_ERR(bp);
 403
 404         *ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0;
 405         return 0;
 406 }
 407
 408 static int ptrace_hbp_get_addr(unsigned int note_type,
 409                                struct task_struct *tsk,
 410                                unsigned long idx,
 411                                u64 *addr)
 412 {
 413         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 414
 415         if (IS_ERR(bp))
 416                 return PTR_ERR(bp);
 417
 418         *addr = bp ? counter_arch_bp(bp)->address : 0;
 419         return 0;
 420 }
 421
 422 static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type,
 423                                                         struct task_struct *tsk,
 424                                                         unsigned long idx)
 425 {
 426         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 427
 428         if (!bp)
 429                 bp = ptrace_hbp_create(note_type, tsk, idx);
 430
 431         return bp;
 432 }
 433
 434 static int ptrace_hbp_set_ctrl(unsigned int note_type,
 435                                struct task_struct *tsk,
 436                                unsigned long idx,
 437                                u32 uctrl)
 438 {
 439         int err;
 440         struct perf_event *bp;
 441         struct perf_event_attr attr;
 442         struct arch_hw_breakpoint_ctrl ctrl;
 443
 444         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 445         if (IS_ERR(bp)) {
 446                 err = PTR_ERR(bp);
 447                 return err;
 448         }
 449
 450         attr = bp->attr;
 451         decode_ctrl_reg(uctrl, &ctrl);
 452         err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
 453         if (err)
 454                 return err;
 455
 456         return modify_user_hw_breakpoint(bp, &attr);
 457 }
 458
 459 static int ptrace_hbp_set_addr(unsigned int note_type,
 460                                struct task_struct *tsk,
 461                                unsigned long idx,
 462                                u64 addr)
 463 {
 464         int err;
 465         struct perf_event *bp;
 466         struct perf_event_attr attr;
 467
 468         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 469         if (IS_ERR(bp)) {
 470                 err = PTR_ERR(bp);
 471                 return err;
 472         }
 473
 474         attr = bp->attr;
 475         attr.bp_addr = addr;
 476         err = modify_user_hw_breakpoint(bp, &attr);
 477         return err;
 478 }
 479
 480 #define PTRACE_HBP_ADDR_SZ      sizeof(u64)
 481 #define PTRACE_HBP_CTRL_SZ      sizeof(u32)
 482 #define PTRACE_HBP_PAD_SZ       sizeof(u32)
 483
 484 static int hw_break_get(struct task_struct *target,
 485                         const struct user_regset *regset,
 486                         unsigned int pos, unsigned int count,
 487                         void *kbuf, void __user *ubuf)
 488 {
 489         unsigned int note_type = regset->core_note_type;
 490         int ret, idx = 0, offset, limit;
 491         u32 info, ctrl;
 492         u64 addr;
 493
 494         /* Resource info */
 495         ret = ptrace_hbp_get_resource_info(note_type, &info);
 496         if (ret)
 497                 return ret;
 498
 499         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0,
 500                                   sizeof(info));
 501         if (ret)
 502                 return ret;
 503
 504         /* Pad */
 505         offset = offsetof(struct user_hwdebug_state, pad);
 506         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, offset,
 507                                        offset + PTRACE_HBP_PAD_SZ);
 508         if (ret)
 509                 return ret;
 510
 511         /* (address, ctrl) registers */
 512         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 513         limit = regset->n * regset->size;
 514         while (count && offset < limit) {
 515                 ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
 516                 if (ret)
 517                         return ret;
 518                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr,
 519                                           offset, offset + PTRACE_HBP_ADDR_SZ);
 520                 if (ret)
 521                         return ret;
 522                 offset += PTRACE_HBP_ADDR_SZ;
 523
 524                 ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
 525                 if (ret)
 526                         return ret;
 527                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl,
 528                                           offset, offset + PTRACE_HBP_CTRL_SZ);
 529                 if (ret)
 530                         return ret;
 531                 offset += PTRACE_HBP_CTRL_SZ;
 532
 533                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 534                                                offset,
 535                                                offset + PTRACE_HBP_PAD_SZ);
 536                 if (ret)
 537                         return ret;
 538                 offset += PTRACE_HBP_PAD_SZ;
 539                 idx++;
 540         }
 541
 542         return 0;
 543 }
 544
 545 static int hw_break_set(struct task_struct *target,
 546                         const struct user_regset *regset,
 547                         unsigned int pos, unsigned int count,
 548                         const void *kbuf, const void __user *ubuf)
 549 {
 550         unsigned int note_type = regset->core_note_type;
 551         int ret, idx = 0, offset, limit;
 552         u32 ctrl;
 553         u64 addr;
 554
 555         /* Resource info and pad */
 556         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 557         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset);
 558         if (ret)
 559                 return ret;
 560
 561         /* (address, ctrl) registers */
 562         limit = regset->n * regset->size;
 563         while (count && offset < limit) {
 564                 if (count < PTRACE_HBP_ADDR_SZ)
 565                         return -EINVAL;
 566                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
 567                                          offset, offset + PTRACE_HBP_ADDR_SZ);
 568                 if (ret)
 569                         return ret;
 570                 ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
 571                 if (ret)
 572                         return ret;
 573                 offset += PTRACE_HBP_ADDR_SZ;
 574
 575                 if (!count)
 576                         break;
 577                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
 578                                          offset, offset + PTRACE_HBP_CTRL_SZ);
 579                 if (ret)
 580                         return ret;
 581                 ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
 582                 if (ret)
 583                         return ret;
 584                 offset += PTRACE_HBP_CTRL_SZ;
 585
 586                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 587                                                 offset,
 588                                                 offset + PTRACE_HBP_PAD_SZ);
 589                 if (ret)
 590                         return ret;
 591                 offset += PTRACE_HBP_PAD_SZ;
 592                 idx++;
 593         }
 594
 595         return 0;
 596 }
 597 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 598
 599 static int gpr_get(struct task_struct *target,
 600                    const struct user_regset *regset,
 601                    unsigned int pos, unsigned int count,
 602                    void *kbuf, void __user *ubuf)
 603 {
 604         struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
 605         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 606 }
 607
 608 static int gpr_set(struct task_struct *target, const struct user_regset *regset,
 609                    unsigned int pos, unsigned int count,
 610                    const void *kbuf, const void __user *ubuf)
 611 {
 612         int ret;
 613         struct user_pt_regs newregs = task_pt_regs(target)->user_regs;
 614
 615         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
 616         if (ret)
 617                 return ret;
 618
 619         if (!valid_user_regs(&newregs, target))
 620                 return -EINVAL;
 621
 622         task_pt_regs(target)->user_regs = newregs;
 623         return 0;
 624 }
 625
 626 /*
 627  * TODO: update fp accessors for lazy context switching (sync/flush hwstate)
 628  */
 629 static int __fpr_get(struct task_struct *target,
 630                      const struct user_regset *regset,
 631                      unsigned int pos, unsigned int count,
 632                      void *kbuf, void __user *ubuf, unsigned int start_pos)
 633 {
 634         struct user_fpsimd_state *uregs;
 635
 636         sve_sync_to_fpsimd(target);
 637
 638         uregs = &target->thread.uw.fpsimd_state;
 639
 640         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs,
 641                                    start_pos, start_pos + sizeof(*uregs));
 642 }
 643
 644 static int fpr_get(struct task_struct *target, const struct user_regset *regset,
 645                    unsigned int pos, unsigned int count,
 646                    void *kbuf, void __user *ubuf)
 647 {
 648         if (target == current)
 649                 fpsimd_preserve_current_state();
 650
 651         return __fpr_get(target, regset, pos, count, kbuf, ubuf, 0);
 652 }
 653
 654 static int __fpr_set(struct task_struct *target,
 655                      const struct user_regset *regset,
 656                      unsigned int pos, unsigned int count,
 657                      const void *kbuf, const void __user *ubuf,
 658                      unsigned int start_pos)
 659 {
 660         int ret;
 661         struct user_fpsimd_state newstate;
 662
 663         /*
 664          * Ensure target->thread.uw.fpsimd_state is up to date, so that a
 665          * short copyin can't resurrect stale data.
 666          */
 667         sve_sync_to_fpsimd(target);
 668
 669         newstate = target->thread.uw.fpsimd_state;
 670
 671         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate,
 672                                  start_pos, start_pos + sizeof(newstate));
 673         if (ret)
 674                 return ret;
 675
 676         target->thread.uw.fpsimd_state = newstate;
 677
 678         return ret;
 679 }
 680
 681 static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 682                    unsigned int pos, unsigned int count,
 683                    const void *kbuf, const void __user *ubuf)
 684 {
 685         int ret;
 686
 687         ret = __fpr_set(target, regset, pos, count, kbuf, ubuf, 0);
 688         if (ret)
 689                 return ret;
 690
 691         sve_sync_from_fpsimd_zeropad(target);
 692         fpsimd_flush_task_state(target);
 693
 694         return ret;
 695 }
 696
 697 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 698                    unsigned int pos, unsigned int count,
 699                    void *kbuf, void __user *ubuf)
 700 {
 701         unsigned long *tls = &target->thread.uw.tp_value;
 702
 703         if (target == current)
 704                 tls_preserve_current_state();
 705
 706         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
 707 }
 708
 709 static int tls_set(struct task_struct *target, const struct user_regset *regset,
 710                    unsigned int pos, unsigned int count,
 711                    const void *kbuf, const void __user *ubuf)
 712 {
 713         int ret;
 714         unsigned long tls = target->thread.uw.tp_value;
 715
 716         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 717         if (ret)
 718                 return ret;
 719
 720         target->thread.uw.tp_value = tls;
 721         return ret;
 722 }
 723
 724 static int system_call_get(struct task_struct *target,
 725                            const struct user_regset *regset,
 726                            unsigned int pos, unsigned int count,
 727                            void *kbuf, void __user *ubuf)
 728 {
 729         int syscallno = task_pt_regs(target)->syscallno;
 730
 731         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 732                                    &syscallno, 0, -1);
 733 }
 734
 735 static int system_call_set(struct task_struct *target,
 736                            const struct user_regset *regset,
 737                            unsigned int pos, unsigned int count,
 738                            const void *kbuf, const void __user *ubuf)
 739 {
 740         int syscallno = task_pt_regs(target)->syscallno;
 741         int ret;
 742
 743         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &syscallno, 0, -1);
 744         if (ret)
 745                 return ret;
 746
 747         task_pt_regs(target)->syscallno = syscallno;
 748         return ret;
 749 }
 750
 751 #ifdef CONFIG_ARM64_SVE
 752
 753 static void sve_init_header_from_task(struct user_sve_header *header,
 754                                       struct task_struct *target)
 755 {
 756         unsigned int vq;
 757
 758         memset(header, 0, sizeof(*header));
 759
 760         header->flags = test_tsk_thread_flag(target, TIF_SVE) ?
 761                 SVE_PT_REGS_SVE : SVE_PT_REGS_FPSIMD;
 762         if (test_tsk_thread_flag(target, TIF_SVE_VL_INHERIT))
 763                 header->flags |= SVE_PT_VL_INHERIT;
 764
 765         header->vl = target->thread.sve_vl;
 766         vq = sve_vq_from_vl(header->vl);
 767
 768         header->max_vl = sve_max_vl;
 769         if (WARN_ON(!sve_vl_valid(sve_max_vl)))
 770                 header->max_vl = header->vl;
 771
 772         header->size = SVE_PT_SIZE(vq, header->flags);
 773         header->max_size = SVE_PT_SIZE(sve_vq_from_vl(header->max_vl),
 774                                       SVE_PT_REGS_SVE);
 775 }
 776
 777 static unsigned int sve_size_from_header(struct user_sve_header const *header)
 778 {
 779         return ALIGN(header->size, SVE_VQ_BYTES);
 780 }
 781
 782 static unsigned int sve_get_size(struct task_struct *target,
 783                                  const struct user_regset *regset)
 784 {
 785         struct user_sve_header header;
 786
 787         if (!system_supports_sve())
 788                 return 0;
 789
 790         sve_init_header_from_task(&header, target);
 791         return sve_size_from_header(&header);
 792 }
 793
 794 static int sve_get(struct task_struct *target,
 795                    const struct user_regset *regset,
 796                    unsigned int pos, unsigned int count,
 797                    void *kbuf, void __user *ubuf)
 798 {
 799         int ret;
 800         struct user_sve_header header;
 801         unsigned int vq;
 802         unsigned long start, end;
 803
 804         if (!system_supports_sve())
 805                 return -EINVAL;
 806
 807         /* Header */
 808         sve_init_header_from_task(&header, target);
 809         vq = sve_vq_from_vl(header.vl);
 810
 811         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &header,
 812                                   0, sizeof(header));
 813         if (ret)
 814                 return ret;
 815
 816         if (target == current)
 817                 fpsimd_preserve_current_state();
 818
 819         /* Registers: FPSIMD-only case */
 820
 821         BUILD_BUG_ON(SVE_PT_FPSIMD_OFFSET != sizeof(header));
 822         if ((header.flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD)
 823                 return __fpr_get(target, regset, pos, count, kbuf, ubuf,
 824                                  SVE_PT_FPSIMD_OFFSET);
 825
 826         /* Otherwise: full SVE case */
 827
 828         BUILD_BUG_ON(SVE_PT_SVE_OFFSET != sizeof(header));
 829         start = SVE_PT_SVE_OFFSET;
 830         end = SVE_PT_SVE_FFR_OFFSET(vq) + SVE_PT_SVE_FFR_SIZE(vq);
 831         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 832                                   target->thread.sve_state,
 833                                   start, end);
 834         if (ret)
 835                 return ret;
 836
 837         start = end;
 838         end = SVE_PT_SVE_FPSR_OFFSET(vq);
 839         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 840                                        start, end);
 841         if (ret)
 842                 return ret;
 843
 844         /*
 845          * Copy fpsr, and fpcr which must follow contiguously in
 846          * struct fpsimd_state:
 847          */
 848         start = end;
 849         end = SVE_PT_SVE_FPCR_OFFSET(vq) + SVE_PT_SVE_FPCR_SIZE;
 850         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 851                                   &target->thread.uw.fpsimd_state.fpsr,
 852                                   start, end);
 853         if (ret)
 854                 return ret;
 855
 856         start = end;
 857         end = sve_size_from_header(&header);
 858         return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 859                                         start, end);
 860 }
 861
 862 static int sve_set(struct task_struct *target,
 863                    const struct user_regset *regset,
 864                    unsigned int pos, unsigned int count,
 865                    const void *kbuf, const void __user *ubuf)
 866 {
 867         int ret;
 868         struct user_sve_header header;
 869         unsigned int vq;
 870         unsigned long start, end;
 871
 872         if (!system_supports_sve())
 873                 return -EINVAL;
 874
 875         /* Header */
 876         if (count < sizeof(header))
 877                 return -EINVAL;
 878         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &header,
 879                                  0, sizeof(header));
 880         if (ret)
 881                 goto out;
 882
 883         /*
 884          * Apart from PT_SVE_REGS_MASK, all PT_SVE_* flags are consumed by
 885          * sve_set_vector_length(), which will also validate them for us:
 886          */
 887         ret = sve_set_vector_length(target, header.vl,
 888                 ((unsigned long)header.flags & ~SVE_PT_REGS_MASK) << 16);
 889         if (ret)
 890                 goto out;
 891
 892         /* Actual VL set may be less than the user asked for: */
 893         vq = sve_vq_from_vl(target->thread.sve_vl);
 894
 895         /* Registers: FPSIMD-only case */
 896
 897         BUILD_BUG_ON(SVE_PT_FPSIMD_OFFSET != sizeof(header));
 898         if ((header.flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD) {
 899                 ret = __fpr_set(target, regset, pos, count, kbuf, ubuf,
 900                                 SVE_PT_FPSIMD_OFFSET);
 901                 clear_tsk_thread_flag(target, TIF_SVE);
 902                 goto out;
 903         }
 904
 905         /* Otherwise: full SVE case */
 906
 907         /*
 908          * If setting a different VL from the requested VL and there is
 909          * register data, the data layout will be wrong: don't even
 910          * try to set the registers in this case.
 911          */
 912         if (count && vq != sve_vq_from_vl(header.vl)) {
 913                 ret = -EIO;
 914                 goto out;
 915         }
 916
 917         sve_alloc(target);
 918
 919         /*
 920          * Ensure target->thread.sve_state is up to date with target's
 921          * FPSIMD regs, so that a short copyin leaves trailing registers
 922          * unmodified.
 923          */
 924         fpsimd_sync_to_sve(target);
 925         set_tsk_thread_flag(target, TIF_SVE);
 926
 927         BUILD_BUG_ON(SVE_PT_SVE_OFFSET != sizeof(header));
 928         start = SVE_PT_SVE_OFFSET;
 929         end = SVE_PT_SVE_FFR_OFFSET(vq) + SVE_PT_SVE_FFR_SIZE(vq);
 930         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 931                                  target->thread.sve_state,
 932                                  start, end);
 933         if (ret)
 934                 goto out;
 935
 936         start = end;
 937         end = SVE_PT_SVE_FPSR_OFFSET(vq);
 938         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 939                                         start, end);
 940         if (ret)
 941                 goto out;
 942
 943         /*
 944          * Copy fpsr, and fpcr which must follow contiguously in
 945          * struct fpsimd_state:
 946          */
 947         start = end;
 948         end = SVE_PT_SVE_FPCR_OFFSET(vq) + SVE_PT_SVE_FPCR_SIZE;
 949         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 950                                  &target->thread.uw.fpsimd_state.fpsr,
 951                                  start, end);
 952
 953 out:
 954         fpsimd_flush_task_state(target);
 955         return ret;
 956 }
 957
 958 #endif /* CONFIG_ARM64_SVE */
 959
 960 enum aarch64_regset {
 961         REGSET_GPR,
 962         REGSET_FPR,
 963         REGSET_TLS,
 964 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 965         REGSET_HW_BREAK,
 966         REGSET_HW_WATCH,
 967 #endif
 968         REGSET_SYSTEM_CALL,
 969 #ifdef CONFIG_ARM64_SVE
 970         REGSET_SVE,
 971 #endif
 972 };
 973
 974 static const struct user_regset aarch64_regsets[] = {
 975         [REGSET_GPR] = {
 976                 .core_note_type = NT_PRSTATUS,
 977                 .n = sizeof(struct user_pt_regs) / sizeof(u64),
 978                 .size = sizeof(u64),
 979                 .align = sizeof(u64),
 980                 .get = gpr_get,
 981                 .set = gpr_set
 982         },
 983         [REGSET_FPR] = {
 984                 .core_note_type = NT_PRFPREG,
 985                 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
 986                 /*
 987                  * We pretend we have 32-bit registers because the fpsr and
 988                  * fpcr are 32-bits wide.
 989                  */
 990                 .size = sizeof(u32),
 991                 .align = sizeof(u32),
 992                 .get = fpr_get,
 993                 .set = fpr_set
 994         },
 995         [REGSET_TLS] = {
 996                 .core_note_type = NT_ARM_TLS,
 997                 .n = 1,
 998                 .size = sizeof(void *),
 999                 .align = sizeof(void *),
1000                 .get = tls_get,
1001                 .set = tls_set,
1002         },
1003 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1004         [REGSET_HW_BREAK] = {
1005                 .core_note_type = NT_ARM_HW_BREAK,
1006                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1007                 .size = sizeof(u32),
1008                 .align = sizeof(u32),
1009                 .get = hw_break_get,
1010                 .set = hw_break_set,
1011         },
1012         [REGSET_HW_WATCH] = {
1013                 .core_note_type = NT_ARM_HW_WATCH,
1014                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1015                 .size = sizeof(u32),
1016                 .align = sizeof(u32),
1017                 .get = hw_break_get,
1018                 .set = hw_break_set,
1019         },
1020 #endif
1021         [REGSET_SYSTEM_CALL] = {
1022                 .core_note_type = NT_ARM_SYSTEM_CALL,
1023                 .n = 1,
1024                 .size = sizeof(int),
1025                 .align = sizeof(int),
1026                 .get = system_call_get,
1027                 .set = system_call_set,
1028         },
1029 #ifdef CONFIG_ARM64_SVE
1030         [REGSET_SVE] = { /* Scalable Vector Extension */
1031                 .core_note_type = NT_ARM_SVE,
1032                 .n = DIV_ROUND_UP(SVE_PT_SIZE(SVE_VQ_MAX, SVE_PT_REGS_SVE),
1033                                   SVE_VQ_BYTES),
1034                 .size = SVE_VQ_BYTES,
1035                 .align = SVE_VQ_BYTES,
1036                 .get = sve_get,
1037                 .set = sve_set,
1038                 .get_size = sve_get_size,
1039         },
1040 #endif
1041 };
1042
1043 static const struct user_regset_view user_aarch64_view = {
1044         .name = "aarch64", .e_machine = EM_AARCH64,
1045         .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
1046 };
1047
1048 #ifdef CONFIG_COMPAT
1049 #include <linux/compat.h>
1050
1051 enum compat_regset {
1052         REGSET_COMPAT_GPR,
1053         REGSET_COMPAT_VFP,
1054 };
1055
1056 static int compat_gpr_get(struct task_struct *target,
1057                           const struct user_regset *regset,
1058                           unsigned int pos, unsigned int count,
1059                           void *kbuf, void __user *ubuf)
1060 {
1061         int ret = 0;
1062         unsigned int i, start, num_regs;
1063
1064         /* Calculate the number of AArch32 registers contained in count */
1065         num_regs = count / regset->size;
1066
1067         /* Convert pos into an register number */
1068         start = pos / regset->size;
1069
1070         if (start + num_regs > regset->n)
1071                 return -EIO;
1072
1073         for (i = 0; i < num_regs; ++i) {
1074                 unsigned int idx = start + i;
1075                 compat_ulong_t reg;
1076
1077                 switch (idx) {
1078                 case 15:
1079                         reg = task_pt_regs(target)->pc;
1080                         break;
1081                 case 16:
1082                         reg = task_pt_regs(target)->pstate;
1083                         break;
1084                 case 17:
1085                         reg = task_pt_regs(target)->orig_x0;
1086                         break;
1087                 default:
1088                         reg = task_pt_regs(target)->regs[idx];
1089                 }
1090
1091                 if (kbuf) {
1092                         memcpy(kbuf, &reg, sizeof(reg));
1093                         kbuf += sizeof(reg);
1094                 } else {
1095                         ret = copy_to_user(ubuf, &reg, sizeof(reg));
1096                         if (ret) {
1097                                 ret = -EFAULT;
1098                                 break;
1099                         }
1100
1101                         ubuf += sizeof(reg);
1102                 }
1103         }
1104
1105         return ret;
1106 }
1107
1108 static int compat_gpr_set(struct task_struct *target,
1109                           const struct user_regset *regset,
1110                           unsigned int pos, unsigned int count,
1111                           const void *kbuf, const void __user *ubuf)
1112 {
1113         struct pt_regs newregs;
1114         int ret = 0;
1115         unsigned int i, start, num_regs;
1116
1117         /* Calculate the number of AArch32 registers contained in count */
1118         num_regs = count / regset->size;
1119
1120         /* Convert pos into an register number */
1121         start = pos / regset->size;
1122
1123         if (start + num_regs > regset->n)
1124                 return -EIO;
1125
1126         newregs = *task_pt_regs(target);
1127
1128         for (i = 0; i < num_regs; ++i) {
1129                 unsigned int idx = start + i;
1130                 compat_ulong_t reg;
1131
1132                 if (kbuf) {
1133                         memcpy(&reg, kbuf, sizeof(reg));
1134                         kbuf += sizeof(reg);
1135                 } else {
1136                         ret = copy_from_user(&reg, ubuf, sizeof(reg));
1137                         if (ret) {
1138                                 ret = -EFAULT;
1139                                 break;
1140                         }
1141
1142                         ubuf += sizeof(reg);
1143                 }
1144
1145                 switch (idx) {
1146                 case 15:
1147                         newregs.pc = reg;
1148                         break;
1149                 case 16:
1150                         newregs.pstate = reg;
1151                         break;
1152                 case 17:
1153                         newregs.orig_x0 = reg;
1154                         break;
1155                 default:
1156                         newregs.regs[idx] = reg;
1157                 }
1158
1159         }
1160
1161         if (valid_user_regs(&newregs.user_regs, target))
1162                 *task_pt_regs(target) = newregs;
1163         else
1164                 ret = -EINVAL;
1165
1166         return ret;
1167 }
1168
1169 static int compat_vfp_get(struct task_struct *target,
1170                           const struct user_regset *regset,
1171                           unsigned int pos, unsigned int count,
1172                           void *kbuf, void __user *ubuf)
1173 {
1174         struct user_fpsimd_state *uregs;
1175         compat_ulong_t fpscr;
1176         int ret, vregs_end_pos;
1177
1178         uregs = &target->thread.uw.fpsimd_state;
1179
1180         if (target == current)
1181                 fpsimd_preserve_current_state();
1182
1183         /*
1184          * The VFP registers are packed into the fpsimd_state, so they all sit
1185          * nicely together for us. We just need to create the fpscr separately.
1186          */
1187         vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t);
1188         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs,
1189                                   0, vregs_end_pos);
1190
1191         if (count && !ret) {
1192                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
1193                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
1194
1195                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &fpscr,
1196                                           vregs_end_pos, VFP_STATE_SIZE);
1197         }
1198
1199         return ret;
1200 }
1201
1202 static int compat_vfp_set(struct task_struct *target,
1203                           const struct user_regset *regset,
1204                           unsigned int pos, unsigned int count,
1205                           const void *kbuf, const void __user *ubuf)
1206 {
1207         struct user_fpsimd_state *uregs;
1208         compat_ulong_t fpscr;
1209         int ret, vregs_end_pos;
1210
1211         uregs = &target->thread.uw.fpsimd_state;
1212
1213         vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t);
1214         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
1215                                  vregs_end_pos);
1216
1217         if (count && !ret) {
1218                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpscr,
1219                                          vregs_end_pos, VFP_STATE_SIZE);
1220                 if (!ret) {
1221                         uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
1222                         uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
1223                 }
1224         }
1225
1226         fpsimd_flush_task_state(target);
1227         return ret;
1228 }
1229
1230 static int compat_tls_get(struct task_struct *target,
1231                           const struct user_regset *regset, unsigned int pos,
1232                           unsigned int count, void *kbuf, void __user *ubuf)
1233 {
1234         compat_ulong_t tls = (compat_ulong_t)target->thread.uw.tp_value;
1235         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
1236 }
1237
1238 static int compat_tls_set(struct task_struct *target,
1239                           const struct user_regset *regset, unsigned int pos,
1240                           unsigned int count, const void *kbuf,
1241                           const void __user *ubuf)
1242 {
1243         int ret;
1244         compat_ulong_t tls = target->thread.uw.tp_value;
1245
1246         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
1247         if (ret)
1248                 return ret;
1249
1250         target->thread.uw.tp_value = tls;
1251         return ret;
1252 }
1253
1254 static const struct user_regset aarch32_regsets[] = {
1255         [REGSET_COMPAT_GPR] = {
1256                 .core_note_type = NT_PRSTATUS,
1257                 .n = COMPAT_ELF_NGREG,
1258                 .size = sizeof(compat_elf_greg_t),
1259                 .align = sizeof(compat_elf_greg_t),
1260                 .get = compat_gpr_get,
1261                 .set = compat_gpr_set
1262         },
1263         [REGSET_COMPAT_VFP] = {
1264                 .core_note_type = NT_ARM_VFP,
1265                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
1266                 .size = sizeof(compat_ulong_t),
1267                 .align = sizeof(compat_ulong_t),
1268                 .get = compat_vfp_get,
1269                 .set = compat_vfp_set
1270         },
1271 };
1272
1273 static const struct user_regset_view user_aarch32_view = {
1274         .name = "aarch32", .e_machine = EM_ARM,
1275         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
1276 };
1277
1278 static const struct user_regset aarch32_ptrace_regsets[] = {
1279         [REGSET_GPR] = {
1280                 .core_note_type = NT_PRSTATUS,
1281                 .n = COMPAT_ELF_NGREG,
1282                 .size = sizeof(compat_elf_greg_t),
1283                 .align = sizeof(compat_elf_greg_t),
1284                 .get = compat_gpr_get,
1285                 .set = compat_gpr_set
1286         },
1287         [REGSET_FPR] = {
1288                 .core_note_type = NT_ARM_VFP,
1289                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
1290                 .size = sizeof(compat_ulong_t),
1291                 .align = sizeof(compat_ulong_t),
1292                 .get = compat_vfp_get,
1293                 .set = compat_vfp_set
1294         },
1295         [REGSET_TLS] = {
1296                 .core_note_type = NT_ARM_TLS,
1297                 .n = 1,
1298                 .size = sizeof(compat_ulong_t),
1299                 .align = sizeof(compat_ulong_t),
1300                 .get = compat_tls_get,
1301                 .set = compat_tls_set,
1302         },
1303 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1304         [REGSET_HW_BREAK] = {
1305                 .core_note_type = NT_ARM_HW_BREAK,
1306                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1307                 .size = sizeof(u32),
1308                 .align = sizeof(u32),
1309                 .get = hw_break_get,
1310                 .set = hw_break_set,
1311         },
1312         [REGSET_HW_WATCH] = {
1313                 .core_note_type = NT_ARM_HW_WATCH,
1314                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1315                 .size = sizeof(u32),
1316                 .align = sizeof(u32),
1317                 .get = hw_break_get,
1318                 .set = hw_break_set,
1319         },
1320 #endif
1321         [REGSET_SYSTEM_CALL] = {
1322                 .core_note_type = NT_ARM_SYSTEM_CALL,
1323                 .n = 1,
1324                 .size = sizeof(int),
1325                 .align = sizeof(int),
1326                 .get = system_call_get,
1327                 .set = system_call_set,
1328         },
1329 };
1330
1331 static const struct user_regset_view user_aarch32_ptrace_view = {
1332         .name = "aarch32", .e_machine = EM_ARM,
1333         .regsets = aarch32_ptrace_regsets, .n = ARRAY_SIZE(aarch32_ptrace_regsets)
1334 };
1335
1336 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
1337                                    compat_ulong_t __user *ret)
1338 {
1339         compat_ulong_t tmp;
1340
1341         if (off & 3)
1342                 return -EIO;
1343
1344         if (off == COMPAT_PT_TEXT_ADDR)
1345                 tmp = tsk->mm->start_code;
1346         else if (off == COMPAT_PT_DATA_ADDR)
1347                 tmp = tsk->mm->start_data;
1348         else if (off == COMPAT_PT_TEXT_END_ADDR)
1349                 tmp = tsk->mm->end_code;
1350         else if (off < sizeof(compat_elf_gregset_t))
1351                 return copy_regset_to_user(tsk, &user_aarch32_view,
1352                                            REGSET_COMPAT_GPR, off,
1353                                            sizeof(compat_ulong_t), ret);
1354         else if (off >= COMPAT_USER_SZ)
1355                 return -EIO;
1356         else
1357                 tmp = 0;
1358
1359         return put_user(tmp, ret);
1360 }
1361
1362 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
1363                                     compat_ulong_t val)
1364 {
1365         int ret;
1366         mm_segment_t old_fs = get_fs();
1367
1368         if (off & 3 || off >= COMPAT_USER_SZ)
1369                 return -EIO;
1370
1371         if (off >= sizeof(compat_elf_gregset_t))
1372                 return 0;
1373
1374         set_fs(KERNEL_DS);
1375         ret = copy_regset_from_user(tsk, &user_aarch32_view,
1376                                     REGSET_COMPAT_GPR, off,
1377                                     sizeof(compat_ulong_t),
1378                                     &val);
1379         set_fs(old_fs);
1380
1381         return ret;
1382 }
1383
1384 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1385
1386 /*
1387  * Convert a virtual register number into an index for a thread_info
1388  * breakpoint array. Breakpoints are identified using positive numbers
1389  * whilst watchpoints are negative. The registers are laid out as pairs
1390  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
1391  * Register 0 is reserved for describing resource information.
1392  */
1393 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
1394 {
1395         return (abs(num) - 1) >> 1;
1396 }
1397
1398 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
1399 {
1400         u8 num_brps, num_wrps, debug_arch, wp_len;
1401         u32 reg = 0;
1402
1403         num_brps        = hw_breakpoint_slots(TYPE_INST);
1404         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
1405
1406         debug_arch      = debug_monitors_arch();
1407         wp_len          = 8;
1408         reg             |= debug_arch;
1409         reg             <<= 8;
1410         reg             |= wp_len;
1411         reg             <<= 8;
1412         reg             |= num_wrps;
1413         reg             <<= 8;
1414         reg             |= num_brps;
1415
1416         *kdata = reg;
1417         return 0;
1418 }
1419
1420 static int compat_ptrace_hbp_get(unsigned int note_type,
1421                                  struct task_struct *tsk,
1422                                  compat_long_t num,
1423                                  u32 *kdata)
1424 {
1425         u64 addr = 0;
1426         u32 ctrl = 0;
1427
1428         int err, idx = compat_ptrace_hbp_num_to_idx(num);
1429
1430         if (num & 1) {
1431                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
1432                 *kdata = (u32)addr;
1433         } else {
1434                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
1435                 *kdata = ctrl;
1436         }
1437
1438         return err;
1439 }
1440
1441 static int compat_ptrace_hbp_set(unsigned int note_type,
1442                                  struct task_struct *tsk,
1443                                  compat_long_t num,
1444                                  u32 *kdata)
1445 {
1446         u64 addr;
1447         u32 ctrl;
1448
1449         int err, idx = compat_ptrace_hbp_num_to_idx(num);
1450
1451         if (num & 1) {
1452                 addr = *kdata;
1453                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
1454         } else {
1455                 ctrl = *kdata;
1456                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
1457         }
1458
1459         return err;
1460 }
1461
1462 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
1463                                     compat_ulong_t __user *data)
1464 {
1465         int ret;
1466         u32 kdata;
1467
1468         /* Watchpoint */
1469         if (num < 0) {
1470                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
1471         /* Resource info */
1472         } else if (num == 0) {
1473                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
1474         /* Breakpoint */
1475         } else {
1476                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
1477         }
1478
1479         if (!ret)
1480                 ret = put_user(kdata, data);
1481
1482         return ret;
1483 }
1484
1485 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
1486                                     compat_ulong_t __user *data)
1487 {
1488         int ret;
1489         u32 kdata = 0;
1490
1491         if (num == 0)
1492                 return 0;
1493
1494         ret = get_user(kdata, data);
1495         if (ret)
1496                 return ret;
1497
1498         if (num < 0)
1499                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
1500         else
1501                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
1502
1503         return ret;
1504 }
1505 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
1506
1507 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1508                         compat_ulong_t caddr, compat_ulong_t cdata)
1509 {
1510         unsigned long addr = caddr;
1511         unsigned long data = cdata;
1512         void __user *datap = compat_ptr(data);
1513         int ret;
1514
1515         switch (request) {
1516                 case PTRACE_PEEKUSR:
1517                         ret = compat_ptrace_read_user(child, addr, datap);
1518                         break;
1519
1520                 case PTRACE_POKEUSR:
1521                         ret = compat_ptrace_write_user(child, addr, data);
1522                         break;
1523
1524                 case COMPAT_PTRACE_GETREGS:
1525                         ret = copy_regset_to_user(child,
1526                                                   &user_aarch32_view,
1527                                                   REGSET_COMPAT_GPR,
1528                                                   0, sizeof(compat_elf_gregset_t),
1529                                                   datap);
1530                         break;
1531
1532                 case COMPAT_PTRACE_SETREGS:
1533                         ret = copy_regset_from_user(child,
1534                                                     &user_aarch32_view,
1535                                                     REGSET_COMPAT_GPR,
1536                                                     0, sizeof(compat_elf_gregset_t),
1537                                                     datap);
1538                         break;
1539
1540                 case COMPAT_PTRACE_GET_THREAD_AREA:
1541                         ret = put_user((compat_ulong_t)child->thread.uw.tp_value,
1542                                        (compat_ulong_t __user *)datap);
1543                         break;
1544
1545                 case COMPAT_PTRACE_SET_SYSCALL:
1546                         task_pt_regs(child)->syscallno = data;
1547                         ret = 0;
1548                         break;
1549
1550                 case COMPAT_PTRACE_GETVFPREGS:
1551                         ret = copy_regset_to_user(child,
1552                                                   &user_aarch32_view,
1553                                                   REGSET_COMPAT_VFP,
1554                                                   0, VFP_STATE_SIZE,
1555                                                   datap);
1556                         break;
1557
1558                 case COMPAT_PTRACE_SETVFPREGS:
1559                         ret = copy_regset_from_user(child,
1560                                                     &user_aarch32_view,
1561                                                     REGSET_COMPAT_VFP,
1562                                                     0, VFP_STATE_SIZE,
1563                                                     datap);
1564                         break;
1565
1566 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1567                 case COMPAT_PTRACE_GETHBPREGS:
1568                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1569                         break;
1570
1571                 case COMPAT_PTRACE_SETHBPREGS:
1572                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1573                         break;
1574 #endif
1575
1576                 default:
1577                         ret = compat_ptrace_request(child, request, addr,
1578                                                     data);
1579                         break;
1580         }
1581
1582         return ret;
1583 }
1584 #endif /* CONFIG_COMPAT */
1585
1586 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1587 {
1588 #ifdef CONFIG_COMPAT
1589         /*
1590          * Core dumping of 32-bit tasks or compat ptrace requests must use the
1591          * user_aarch32_view compatible with arm32. Native ptrace requests on
1592          * 32-bit children use an extended user_aarch32_ptrace_view to allow
1593          * access to the TLS register.
1594          */
1595         if (is_compat_task())
1596                 return &user_aarch32_view;
1597         else if (is_compat_thread(task_thread_info(task)))
1598                 return &user_aarch32_ptrace_view;
1599 #endif
1600         return &user_aarch64_view;
1601 }
1602
1603 long arch_ptrace(struct task_struct *child, long request,
1604                  unsigned long addr, unsigned long data)
1605 {
1606         return ptrace_request(child, request, addr, data);
1607 }
1608
1609 enum ptrace_syscall_dir {
1610         PTRACE_SYSCALL_ENTER = 0,
1611         PTRACE_SYSCALL_EXIT,
1612 };
1613
1614 static void tracehook_report_syscall(struct pt_regs *regs,
1615                                      enum ptrace_syscall_dir dir)
1616 {
1617         int regno;
1618         unsigned long saved_reg;
1619
1620         /*
1621          * A scratch register (ip(r12) on AArch32, x7 on AArch64) is
1622          * used to denote syscall entry/exit:
1623          */
1624         regno = (is_compat_task() ? 12 : 7);
1625         saved_reg = regs->regs[regno];
1626         regs->regs[regno] = dir;
1627
1628         if (dir == PTRACE_SYSCALL_EXIT)
1629                 tracehook_report_syscall_exit(regs, 0);
1630         else if (tracehook_report_syscall_entry(regs))
1631                 forget_syscall(regs);
1632
1633         regs->regs[regno] = saved_reg;
1634 }
1635
1636 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
1637 {
1638         if (test_thread_flag(TIF_SYSCALL_TRACE))
1639                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1640
1641         /* Do the secure computing after ptrace; failures should be fast. */
1642         if (secure_computing(NULL) == -1)
1643                 return -1;
1644
1645         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1646                 trace_sys_enter(regs, regs->syscallno);
1647
1648         audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1],
1649                             regs->regs[2], regs->regs[3]);
1650
1651         return regs->syscallno;
1652 }
1653
1654 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
1655 {
1656         audit_syscall_exit(regs);
1657
1658         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1659                 trace_sys_exit(regs, regs_return_value(regs));
1660
1661         if (test_thread_flag(TIF_SYSCALL_TRACE))
1662                 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1663 }
1664
1665 /*
1666  * Bits which are always architecturally RES0 per ARM DDI 0487A.h
1667  * Userspace cannot use these until they have an architectural meaning.
1668  * We also reserve IL for the kernel; SS is handled dynamically.
1669  */
1670 #define SPSR_EL1_AARCH64_RES0_BITS \
1671         (GENMASK_ULL(63,32) | GENMASK_ULL(27, 22) | GENMASK_ULL(20, 10) | \
1672          GENMASK_ULL(5, 5))
1673 #define SPSR_EL1_AARCH32_RES0_BITS \
1674         (GENMASK_ULL(63,32) | GENMASK_ULL(24, 22) | GENMASK_ULL(20,20))
1675
1676 static int valid_compat_regs(struct user_pt_regs *regs)
1677 {
1678         regs->pstate &= ~SPSR_EL1_AARCH32_RES0_BITS;
1679
1680         if (!system_supports_mixed_endian_el0()) {
1681                 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
1682                         regs->pstate |= COMPAT_PSR_E_BIT;
1683                 else
1684                         regs->pstate &= ~COMPAT_PSR_E_BIT;
1685         }
1686
1687         if (user_mode(regs) && (regs->pstate & PSR_MODE32_BIT) &&
1688             (regs->pstate & COMPAT_PSR_A_BIT) == 0 &&
1689             (regs->pstate & COMPAT_PSR_I_BIT) == 0 &&
1690             (regs->pstate & COMPAT_PSR_F_BIT) == 0) {
1691                 return 1;
1692         }
1693
1694         /*
1695          * Force PSR to a valid 32-bit EL0t, preserving the same bits as
1696          * arch/arm.
1697          */
1698         regs->pstate &= COMPAT_PSR_N_BIT | COMPAT_PSR_Z_BIT |
1699                         COMPAT_PSR_C_BIT | COMPAT_PSR_V_BIT |
1700                         COMPAT_PSR_Q_BIT | COMPAT_PSR_IT_MASK |
1701                         COMPAT_PSR_GE_MASK | COMPAT_PSR_E_BIT |
1702                         COMPAT_PSR_T_BIT;
1703         regs->pstate |= PSR_MODE32_BIT;
1704
1705         return 0;
1706 }
1707
1708 static int valid_native_regs(struct user_pt_regs *regs)
1709 {
1710         regs->pstate &= ~SPSR_EL1_AARCH64_RES0_BITS;
1711
1712         if (user_mode(regs) && !(regs->pstate & PSR_MODE32_BIT) &&
1713             (regs->pstate & PSR_D_BIT) == 0 &&
1714             (regs->pstate & PSR_A_BIT) == 0 &&
1715             (regs->pstate & PSR_I_BIT) == 0 &&
1716             (regs->pstate & PSR_F_BIT) == 0) {
1717                 return 1;
1718         }
1719
1720         /* Force PSR to a valid 64-bit EL0t */
1721         regs->pstate &= PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT;
1722
1723         return 0;
1724 }
1725
1726 /*
1727  * Are the current registers suitable for user mode? (used to maintain
1728  * security in signal handlers)
1729  */
1730 int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task)
1731 {
1732         if (!test_tsk_thread_flag(task, TIF_SINGLESTEP))
1733                 regs->pstate &= ~DBG_SPSR_SS;
1734
1735         if (is_compat_thread(task_thread_info(task)))
1736                 return valid_compat_regs(regs);
1737         else
1738                 return valid_native_regs(regs);
1739 }