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/fpsimd.h>
  48 #include <asm/pgtable.h>
  49 #include <asm/stacktrace.h>
  50 #include <asm/syscall.h>
  51 #include <asm/traps.h>
  52 #include <asm/system_misc.h>
  53
  54 #define CREATE_TRACE_POINTS
  55 #include <trace/events/syscalls.h>
  56
  57 struct pt_regs_offset {
  58         const char *name;
  59         int offset;
  60 };
  61
  62 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  63 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  64 #define GPR_OFFSET_NAME(r) \
  65         {.name = "x" #r, .offset = offsetof(struct pt_regs, regs[r])}
  66
  67 static const struct pt_regs_offset regoffset_table[] = {
  68         GPR_OFFSET_NAME(0),
  69         GPR_OFFSET_NAME(1),
  70         GPR_OFFSET_NAME(2),
  71         GPR_OFFSET_NAME(3),
  72         GPR_OFFSET_NAME(4),
  73         GPR_OFFSET_NAME(5),
  74         GPR_OFFSET_NAME(6),
  75         GPR_OFFSET_NAME(7),
  76         GPR_OFFSET_NAME(8),
  77         GPR_OFFSET_NAME(9),
  78         GPR_OFFSET_NAME(10),
  79         GPR_OFFSET_NAME(11),
  80         GPR_OFFSET_NAME(12),
  81         GPR_OFFSET_NAME(13),
  82         GPR_OFFSET_NAME(14),
  83         GPR_OFFSET_NAME(15),
  84         GPR_OFFSET_NAME(16),
  85         GPR_OFFSET_NAME(17),
  86         GPR_OFFSET_NAME(18),
  87         GPR_OFFSET_NAME(19),
  88         GPR_OFFSET_NAME(20),
  89         GPR_OFFSET_NAME(21),
  90         GPR_OFFSET_NAME(22),
  91         GPR_OFFSET_NAME(23),
  92         GPR_OFFSET_NAME(24),
  93         GPR_OFFSET_NAME(25),
  94         GPR_OFFSET_NAME(26),
  95         GPR_OFFSET_NAME(27),
  96         GPR_OFFSET_NAME(28),
  97         GPR_OFFSET_NAME(29),
  98         GPR_OFFSET_NAME(30),
  99         {.name = "lr", .offset = offsetof(struct pt_regs, regs[30])},
 100         REG_OFFSET_NAME(sp),
 101         REG_OFFSET_NAME(pc),
 102         REG_OFFSET_NAME(pstate),
 103         REG_OFFSET_END,
 104 };
 105
 106 /**
 107  * regs_query_register_offset() - query register offset from its name
 108  * @name:       the name of a register
 109  *
 110  * regs_query_register_offset() returns the offset of a register in struct
 111  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 112  */
 113 int regs_query_register_offset(const char *name)
 114 {
 115         const struct pt_regs_offset *roff;
 116
 117         for (roff = regoffset_table; roff->name != NULL; roff++)
 118                 if (!strcmp(roff->name, name))
 119                         return roff->offset;
 120         return -EINVAL;
 121 }
 122
 123 /**
 124  * regs_within_kernel_stack() - check the address in the stack
 125  * @regs:      pt_regs which contains kernel stack pointer.
 126  * @addr:      address which is checked.
 127  *
 128  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 129  * If @addr is within the kernel stack, it returns true. If not, returns false.
 130  */
 131 static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 132 {
 133         return ((addr & ~(THREAD_SIZE - 1))  ==
 134                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))) ||
 135                 on_irq_stack(addr);
 136 }
 137
 138 /**
 139  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 140  * @regs:       pt_regs which contains kernel stack pointer.
 141  * @n:          stack entry number.
 142  *
 143  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 144  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 145  * this returns 0.
 146  */
 147 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 148 {
 149         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 150
 151         addr += n;
 152         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 153                 return *addr;
 154         else
 155                 return 0;
 156 }
 157
 158 /*
 159  * TODO: does not yet catch signals sent when the child dies.
 160  * in exit.c or in signal.c.
 161  */
 162
 163 /*
 164  * Called by kernel/ptrace.c when detaching..
 165  */
 166 void ptrace_disable(struct task_struct *child)
 167 {
 168         /*
 169          * This would be better off in core code, but PTRACE_DETACH has
 170          * grown its fair share of arch-specific worts and changing it
 171          * is likely to cause regressions on obscure architectures.
 172          */
 173         user_disable_single_step(child);
 174 }
 175
 176 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 177 /*
 178  * Handle hitting a HW-breakpoint.
 179  */
 180 static void ptrace_hbptriggered(struct perf_event *bp,
 181                                 struct perf_sample_data *data,
 182                                 struct pt_regs *regs)
 183 {
 184         struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
 185         siginfo_t info;
 186
 187         clear_siginfo(&info);
 188         info.si_signo   = SIGTRAP;
 189         info.si_errno   = 0;
 190         info.si_code    = TRAP_HWBKPT;
 191         info.si_addr    = (void __user *)(bkpt->trigger);
 192
 193 #ifdef CONFIG_COMPAT
 194         if (is_compat_task()) {
 195                 int si_errno = 0;
 196                 int i;
 197
 198                 for (i = 0; i < ARM_MAX_BRP; ++i) {
 199                         if (current->thread.debug.hbp_break[i] == bp) {
 200                                 si_errno = (i << 1) + 1;
 201                                 break;
 202                         }
 203                 }
 204
 205                 for (i = 0; i < ARM_MAX_WRP; ++i) {
 206                         if (current->thread.debug.hbp_watch[i] == bp) {
 207                                 si_errno = -((i << 1) + 1);
 208                                 break;
 209                         }
 210                 }
 211                 force_sig_ptrace_errno_trap(si_errno, (void __user *)bkpt->trigger);
 212         }
 213 #endif
 214         arm64_force_sig_info(&info, "Hardware breakpoint trap (ptrace)", current);
 215 }
 216
 217 /*
 218  * Unregister breakpoints from this task and reset the pointers in
 219  * the thread_struct.
 220  */
 221 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 222 {
 223         int i;
 224         struct thread_struct *t = &tsk->thread;
 225
 226         for (i = 0; i < ARM_MAX_BRP; i++) {
 227                 if (t->debug.hbp_break[i]) {
 228                         unregister_hw_breakpoint(t->debug.hbp_break[i]);
 229                         t->debug.hbp_break[i] = NULL;
 230                 }
 231         }
 232
 233         for (i = 0; i < ARM_MAX_WRP; i++) {
 234                 if (t->debug.hbp_watch[i]) {
 235                         unregister_hw_breakpoint(t->debug.hbp_watch[i]);
 236                         t->debug.hbp_watch[i] = NULL;
 237                 }
 238         }
 239 }
 240
 241 void ptrace_hw_copy_thread(struct task_struct *tsk)
 242 {
 243         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 244 }
 245
 246 static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
 247                                                struct task_struct *tsk,
 248                                                unsigned long idx)
 249 {
 250         struct perf_event *bp = ERR_PTR(-EINVAL);
 251
 252         switch (note_type) {
 253         case NT_ARM_HW_BREAK:
 254                 if (idx >= ARM_MAX_BRP)
 255                         goto out;
 256                 idx = array_index_nospec(idx, ARM_MAX_BRP);
 257                 bp = tsk->thread.debug.hbp_break[idx];
 258                 break;
 259         case NT_ARM_HW_WATCH:
 260                 if (idx >= ARM_MAX_WRP)
 261                         goto out;
 262                 idx = array_index_nospec(idx, ARM_MAX_WRP);
 263                 bp = tsk->thread.debug.hbp_watch[idx];
 264                 break;
 265         }
 266
 267 out:
 268         return bp;
 269 }
 270
 271 static int ptrace_hbp_set_event(unsigned int note_type,
 272                                 struct task_struct *tsk,
 273                                 unsigned long idx,
 274                                 struct perf_event *bp)
 275 {
 276         int err = -EINVAL;
 277
 278         switch (note_type) {
 279         case NT_ARM_HW_BREAK:
 280                 if (idx < ARM_MAX_BRP) {
 281                         tsk->thread.debug.hbp_break[idx] = bp;
 282                         err = 0;
 283                 }
 284                 break;
 285         case NT_ARM_HW_WATCH:
 286                 if (idx < ARM_MAX_WRP) {
 287                         tsk->thread.debug.hbp_watch[idx] = bp;
 288                         err = 0;
 289                 }
 290                 break;
 291         }
 292
 293         return err;
 294 }
 295
 296 static struct perf_event *ptrace_hbp_create(unsigned int note_type,
 297                                             struct task_struct *tsk,
 298                                             unsigned long idx)
 299 {
 300         struct perf_event *bp;
 301         struct perf_event_attr attr;
 302         int err, type;
 303
 304         switch (note_type) {
 305         case NT_ARM_HW_BREAK:
 306                 type = HW_BREAKPOINT_X;
 307                 break;
 308         case NT_ARM_HW_WATCH:
 309                 type = HW_BREAKPOINT_RW;
 310                 break;
 311         default:
 312                 return ERR_PTR(-EINVAL);
 313         }
 314
 315         ptrace_breakpoint_init(&attr);
 316
 317         /*
 318          * Initialise fields to sane defaults
 319          * (i.e. values that will pass validation).
 320          */
 321         attr.bp_addr    = 0;
 322         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 323         attr.bp_type    = type;
 324         attr.disabled   = 1;
 325
 326         bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk);
 327         if (IS_ERR(bp))
 328                 return bp;
 329
 330         err = ptrace_hbp_set_event(note_type, tsk, idx, bp);
 331         if (err)
 332                 return ERR_PTR(err);
 333
 334         return bp;
 335 }
 336
 337 static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
 338                                      struct arch_hw_breakpoint_ctrl ctrl,
 339                                      struct perf_event_attr *attr)
 340 {
 341         int err, len, type, offset, disabled = !ctrl.enabled;
 342
 343         attr->disabled = disabled;
 344         if (disabled)
 345                 return 0;
 346
 347         err = arch_bp_generic_fields(ctrl, &len, &type, &offset);
 348         if (err)
 349                 return err;
 350
 351         switch (note_type) {
 352         case NT_ARM_HW_BREAK:
 353                 if ((type & HW_BREAKPOINT_X) != type)
 354                         return -EINVAL;
 355                 break;
 356         case NT_ARM_HW_WATCH:
 357                 if ((type & HW_BREAKPOINT_RW) != type)
 358                         return -EINVAL;
 359                 break;
 360         default:
 361                 return -EINVAL;
 362         }
 363
 364         attr->bp_len    = len;
 365         attr->bp_type   = type;
 366         attr->bp_addr   += offset;
 367
 368         return 0;
 369 }
 370
 371 static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info)
 372 {
 373         u8 num;
 374         u32 reg = 0;
 375
 376         switch (note_type) {
 377         case NT_ARM_HW_BREAK:
 378                 num = hw_breakpoint_slots(TYPE_INST);
 379                 break;
 380         case NT_ARM_HW_WATCH:
 381                 num = hw_breakpoint_slots(TYPE_DATA);
 382                 break;
 383         default:
 384                 return -EINVAL;
 385         }
 386
 387         reg |= debug_monitors_arch();
 388         reg <<= 8;
 389         reg |= num;
 390
 391         *info = reg;
 392         return 0;
 393 }
 394
 395 static int ptrace_hbp_get_ctrl(unsigned int note_type,
 396                                struct task_struct *tsk,
 397                                unsigned long idx,
 398                                u32 *ctrl)
 399 {
 400         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 401
 402         if (IS_ERR(bp))
 403                 return PTR_ERR(bp);
 404
 405         *ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0;
 406         return 0;
 407 }
 408
 409 static int ptrace_hbp_get_addr(unsigned int note_type,
 410                                struct task_struct *tsk,
 411                                unsigned long idx,
 412                                u64 *addr)
 413 {
 414         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 415
 416         if (IS_ERR(bp))
 417                 return PTR_ERR(bp);
 418
 419         *addr = bp ? counter_arch_bp(bp)->address : 0;
 420         return 0;
 421 }
 422
 423 static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type,
 424                                                         struct task_struct *tsk,
 425                                                         unsigned long idx)
 426 {
 427         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 428
 429         if (!bp)
 430                 bp = ptrace_hbp_create(note_type, tsk, idx);
 431
 432         return bp;
 433 }
 434
 435 static int ptrace_hbp_set_ctrl(unsigned int note_type,
 436                                struct task_struct *tsk,
 437                                unsigned long idx,
 438                                u32 uctrl)
 439 {
 440         int err;
 441         struct perf_event *bp;
 442         struct perf_event_attr attr;
 443         struct arch_hw_breakpoint_ctrl ctrl;
 444
 445         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 446         if (IS_ERR(bp)) {
 447                 err = PTR_ERR(bp);
 448                 return err;
 449         }
 450
 451         attr = bp->attr;
 452         decode_ctrl_reg(uctrl, &ctrl);
 453         err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
 454         if (err)
 455                 return err;
 456
 457         return modify_user_hw_breakpoint(bp, &attr);
 458 }
 459
 460 static int ptrace_hbp_set_addr(unsigned int note_type,
 461                                struct task_struct *tsk,
 462                                unsigned long idx,
 463                                u64 addr)
 464 {
 465         int err;
 466         struct perf_event *bp;
 467         struct perf_event_attr attr;
 468
 469         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 470         if (IS_ERR(bp)) {
 471                 err = PTR_ERR(bp);
 472                 return err;
 473         }
 474
 475         attr = bp->attr;
 476         attr.bp_addr = addr;
 477         err = modify_user_hw_breakpoint(bp, &attr);
 478         return err;
 479 }
 480
 481 #define PTRACE_HBP_ADDR_SZ      sizeof(u64)
 482 #define PTRACE_HBP_CTRL_SZ      sizeof(u32)
 483 #define PTRACE_HBP_PAD_SZ       sizeof(u32)
 484
 485 static int hw_break_get(struct task_struct *target,
 486                         const struct user_regset *regset,
 487                         unsigned int pos, unsigned int count,
 488                         void *kbuf, void __user *ubuf)
 489 {
 490         unsigned int note_type = regset->core_note_type;
 491         int ret, idx = 0, offset, limit;
 492         u32 info, ctrl;
 493         u64 addr;
 494
 495         /* Resource info */
 496         ret = ptrace_hbp_get_resource_info(note_type, &info);
 497         if (ret)
 498                 return ret;
 499
 500         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0,
 501                                   sizeof(info));
 502         if (ret)
 503                 return ret;
 504
 505         /* Pad */
 506         offset = offsetof(struct user_hwdebug_state, pad);
 507         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, offset,
 508                                        offset + PTRACE_HBP_PAD_SZ);
 509         if (ret)
 510                 return ret;
 511
 512         /* (address, ctrl) registers */
 513         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 514         limit = regset->n * regset->size;
 515         while (count && offset < limit) {
 516                 ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
 517                 if (ret)
 518                         return ret;
 519                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr,
 520                                           offset, offset + PTRACE_HBP_ADDR_SZ);
 521                 if (ret)
 522                         return ret;
 523                 offset += PTRACE_HBP_ADDR_SZ;
 524
 525                 ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
 526                 if (ret)
 527                         return ret;
 528                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl,
 529                                           offset, offset + PTRACE_HBP_CTRL_SZ);
 530                 if (ret)
 531                         return ret;
 532                 offset += PTRACE_HBP_CTRL_SZ;
 533
 534                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 535                                                offset,
 536                                                offset + PTRACE_HBP_PAD_SZ);
 537                 if (ret)
 538                         return ret;
 539                 offset += PTRACE_HBP_PAD_SZ;
 540                 idx++;
 541         }
 542
 543         return 0;
 544 }
 545
 546 static int hw_break_set(struct task_struct *target,
 547                         const struct user_regset *regset,
 548                         unsigned int pos, unsigned int count,
 549                         const void *kbuf, const void __user *ubuf)
 550 {
 551         unsigned int note_type = regset->core_note_type;
 552         int ret, idx = 0, offset, limit;
 553         u32 ctrl;
 554         u64 addr;
 555
 556         /* Resource info and pad */
 557         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 558         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset);
 559         if (ret)
 560                 return ret;
 561
 562         /* (address, ctrl) registers */
 563         limit = regset->n * regset->size;
 564         while (count && offset < limit) {
 565                 if (count < PTRACE_HBP_ADDR_SZ)
 566                         return -EINVAL;
 567                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
 568                                          offset, offset + PTRACE_HBP_ADDR_SZ);
 569                 if (ret)
 570                         return ret;
 571                 ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
 572                 if (ret)
 573                         return ret;
 574                 offset += PTRACE_HBP_ADDR_SZ;
 575
 576                 if (!count)
 577                         break;
 578                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
 579                                          offset, offset + PTRACE_HBP_CTRL_SZ);
 580                 if (ret)
 581                         return ret;
 582                 ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
 583                 if (ret)
 584                         return ret;
 585                 offset += PTRACE_HBP_CTRL_SZ;
 586
 587                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 588                                                 offset,
 589                                                 offset + PTRACE_HBP_PAD_SZ);
 590                 if (ret)
 591                         return ret;
 592                 offset += PTRACE_HBP_PAD_SZ;
 593                 idx++;
 594         }
 595
 596         return 0;
 597 }
 598 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 599
 600 static int gpr_get(struct task_struct *target,
 601                    const struct user_regset *regset,
 602                    unsigned int pos, unsigned int count,
 603                    void *kbuf, void __user *ubuf)
 604 {
 605         struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
 606         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 607 }
 608
 609 static int gpr_set(struct task_struct *target, const struct user_regset *regset,
 610                    unsigned int pos, unsigned int count,
 611                    const void *kbuf, const void __user *ubuf)
 612 {
 613         int ret;
 614         struct user_pt_regs newregs = task_pt_regs(target)->user_regs;
 615
 616         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
 617         if (ret)
 618                 return ret;
 619
 620         if (!valid_user_regs(&newregs, target))
 621                 return -EINVAL;
 622
 623         task_pt_regs(target)->user_regs = newregs;
 624         return 0;
 625 }
 626
 627 /*
 628  * TODO: update fp accessors for lazy context switching (sync/flush hwstate)
 629  */
 630 static int __fpr_get(struct task_struct *target,
 631                      const struct user_regset *regset,
 632                      unsigned int pos, unsigned int count,
 633                      void *kbuf, void __user *ubuf, unsigned int start_pos)
 634 {
 635         struct user_fpsimd_state *uregs;
 636
 637         sve_sync_to_fpsimd(target);
 638
 639         uregs = &target->thread.uw.fpsimd_state;
 640
 641         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs,
 642                                    start_pos, start_pos + sizeof(*uregs));
 643 }
 644
 645 static int fpr_get(struct task_struct *target, const struct user_regset *regset,
 646                    unsigned int pos, unsigned int count,
 647                    void *kbuf, void __user *ubuf)
 648 {
 649         if (target == current)
 650                 fpsimd_preserve_current_state();
 651
 652         return __fpr_get(target, regset, pos, count, kbuf, ubuf, 0);
 653 }
 654
 655 static int __fpr_set(struct task_struct *target,
 656                      const struct user_regset *regset,
 657                      unsigned int pos, unsigned int count,
 658                      const void *kbuf, const void __user *ubuf,
 659                      unsigned int start_pos)
 660 {
 661         int ret;
 662         struct user_fpsimd_state newstate;
 663
 664         /*
 665          * Ensure target->thread.uw.fpsimd_state is up to date, so that a
 666          * short copyin can't resurrect stale data.
 667          */
 668         sve_sync_to_fpsimd(target);
 669
 670         newstate = target->thread.uw.fpsimd_state;
 671
 672         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate,
 673                                  start_pos, start_pos + sizeof(newstate));
 674         if (ret)
 675                 return ret;
 676
 677         target->thread.uw.fpsimd_state = newstate;
 678
 679         return ret;
 680 }
 681
 682 static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 683                    unsigned int pos, unsigned int count,
 684                    const void *kbuf, const void __user *ubuf)
 685 {
 686         int ret;
 687
 688         ret = __fpr_set(target, regset, pos, count, kbuf, ubuf, 0);
 689         if (ret)
 690                 return ret;
 691
 692         sve_sync_from_fpsimd_zeropad(target);
 693         fpsimd_flush_task_state(target);
 694
 695         return ret;
 696 }
 697
 698 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 699                    unsigned int pos, unsigned int count,
 700                    void *kbuf, void __user *ubuf)
 701 {
 702         unsigned long *tls = &target->thread.uw.tp_value;
 703
 704         if (target == current)
 705                 tls_preserve_current_state();
 706
 707         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
 708 }
 709
 710 static int tls_set(struct task_struct *target, const struct user_regset *regset,
 711                    unsigned int pos, unsigned int count,
 712                    const void *kbuf, const void __user *ubuf)
 713 {
 714         int ret;
 715         unsigned long tls = target->thread.uw.tp_value;
 716
 717         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 718         if (ret)
 719                 return ret;
 720
 721         target->thread.uw.tp_value = tls;
 722         return ret;
 723 }
 724
 725 static int system_call_get(struct task_struct *target,
 726                            const struct user_regset *regset,
 727                            unsigned int pos, unsigned int count,
 728                            void *kbuf, void __user *ubuf)
 729 {
 730         int syscallno = task_pt_regs(target)->syscallno;
 731
 732         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 733                                    &syscallno, 0, -1);
 734 }
 735
 736 static int system_call_set(struct task_struct *target,
 737                            const struct user_regset *regset,
 738                            unsigned int pos, unsigned int count,
 739                            const void *kbuf, const void __user *ubuf)
 740 {
 741         int syscallno = task_pt_regs(target)->syscallno;
 742         int ret;
 743
 744         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &syscallno, 0, -1);
 745         if (ret)
 746                 return ret;
 747
 748         task_pt_regs(target)->syscallno = syscallno;
 749         return ret;
 750 }
 751
 752 #ifdef CONFIG_ARM64_SVE
 753
 754 static void sve_init_header_from_task(struct user_sve_header *header,
 755                                       struct task_struct *target)
 756 {
 757         unsigned int vq;
 758
 759         memset(header, 0, sizeof(*header));
 760
 761         header->flags = test_tsk_thread_flag(target, TIF_SVE) ?
 762                 SVE_PT_REGS_SVE : SVE_PT_REGS_FPSIMD;
 763         if (test_tsk_thread_flag(target, TIF_SVE_VL_INHERIT))
 764                 header->flags |= SVE_PT_VL_INHERIT;
 765
 766         header->vl = target->thread.sve_vl;
 767         vq = sve_vq_from_vl(header->vl);
 768
 769         header->max_vl = sve_max_vl;
 770         header->size = SVE_PT_SIZE(vq, header->flags);
 771         header->max_size = SVE_PT_SIZE(sve_vq_from_vl(header->max_vl),
 772                                       SVE_PT_REGS_SVE);
 773 }
 774
 775 static unsigned int sve_size_from_header(struct user_sve_header const *header)
 776 {
 777         return ALIGN(header->size, SVE_VQ_BYTES);
 778 }
 779
 780 static unsigned int sve_get_size(struct task_struct *target,
 781                                  const struct user_regset *regset)
 782 {
 783         struct user_sve_header header;
 784
 785         if (!system_supports_sve())
 786                 return 0;
 787
 788         sve_init_header_from_task(&header, target);
 789         return sve_size_from_header(&header);
 790 }
 791
 792 static int sve_get(struct task_struct *target,
 793                    const struct user_regset *regset,
 794                    unsigned int pos, unsigned int count,
 795                    void *kbuf, 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         sve_init_header_from_task(&header, target);
 807         vq = sve_vq_from_vl(header.vl);
 808
 809         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &header,
 810                                   0, sizeof(header));
 811         if (ret)
 812                 return ret;
 813
 814         if (target == current)
 815                 fpsimd_preserve_current_state();
 816
 817         /* Registers: FPSIMD-only case */
 818
 819         BUILD_BUG_ON(SVE_PT_FPSIMD_OFFSET != sizeof(header));
 820         if ((header.flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD)
 821                 return __fpr_get(target, regset, pos, count, kbuf, ubuf,
 822                                  SVE_PT_FPSIMD_OFFSET);
 823
 824         /* Otherwise: full SVE case */
 825
 826         BUILD_BUG_ON(SVE_PT_SVE_OFFSET != sizeof(header));
 827         start = SVE_PT_SVE_OFFSET;
 828         end = SVE_PT_SVE_FFR_OFFSET(vq) + SVE_PT_SVE_FFR_SIZE(vq);
 829         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 830                                   target->thread.sve_state,
 831                                   start, end);
 832         if (ret)
 833                 return ret;
 834
 835         start = end;
 836         end = SVE_PT_SVE_FPSR_OFFSET(vq);
 837         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 838                                        start, end);
 839         if (ret)
 840                 return ret;
 841
 842         /*
 843          * Copy fpsr, and fpcr which must follow contiguously in
 844          * struct fpsimd_state:
 845          */
 846         start = end;
 847         end = SVE_PT_SVE_FPCR_OFFSET(vq) + SVE_PT_SVE_FPCR_SIZE;
 848         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 849                                   &target->thread.uw.fpsimd_state.fpsr,
 850                                   start, end);
 851         if (ret)
 852                 return ret;
 853
 854         start = end;
 855         end = sve_size_from_header(&header);
 856         return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 857                                         start, end);
 858 }
 859
 860 static int sve_set(struct task_struct *target,
 861                    const struct user_regset *regset,
 862                    unsigned int pos, unsigned int count,
 863                    const void *kbuf, const void __user *ubuf)
 864 {
 865         int ret;
 866         struct user_sve_header header;
 867         unsigned int vq;
 868         unsigned long start, end;
 869
 870         if (!system_supports_sve())
 871                 return -EINVAL;
 872
 873         /* Header */
 874         if (count < sizeof(header))
 875                 return -EINVAL;
 876         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &header,
 877                                  0, sizeof(header));
 878         if (ret)
 879                 goto out;
 880
 881         /*
 882          * Apart from PT_SVE_REGS_MASK, all PT_SVE_* flags are consumed by
 883          * sve_set_vector_length(), which will also validate them for us:
 884          */
 885         ret = sve_set_vector_length(target, header.vl,
 886                 ((unsigned long)header.flags & ~SVE_PT_REGS_MASK) << 16);
 887         if (ret)
 888                 goto out;
 889
 890         /* Actual VL set may be less than the user asked for: */
 891         vq = sve_vq_from_vl(target->thread.sve_vl);
 892
 893         /* Registers: FPSIMD-only case */
 894
 895         BUILD_BUG_ON(SVE_PT_FPSIMD_OFFSET != sizeof(header));
 896         if ((header.flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD) {
 897                 ret = __fpr_set(target, regset, pos, count, kbuf, ubuf,
 898                                 SVE_PT_FPSIMD_OFFSET);
 899                 clear_tsk_thread_flag(target, TIF_SVE);
 900                 goto out;
 901         }
 902
 903         /* Otherwise: full SVE case */
 904
 905         /*
 906          * If setting a different VL from the requested VL and there is
 907          * register data, the data layout will be wrong: don't even
 908          * try to set the registers in this case.
 909          */
 910         if (count && vq != sve_vq_from_vl(header.vl)) {
 911                 ret = -EIO;
 912                 goto out;
 913         }
 914
 915         sve_alloc(target);
 916
 917         /*
 918          * Ensure target->thread.sve_state is up to date with target's
 919          * FPSIMD regs, so that a short copyin leaves trailing registers
 920          * unmodified.
 921          */
 922         fpsimd_sync_to_sve(target);
 923         set_tsk_thread_flag(target, TIF_SVE);
 924
 925         BUILD_BUG_ON(SVE_PT_SVE_OFFSET != sizeof(header));
 926         start = SVE_PT_SVE_OFFSET;
 927         end = SVE_PT_SVE_FFR_OFFSET(vq) + SVE_PT_SVE_FFR_SIZE(vq);
 928         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 929                                  target->thread.sve_state,
 930                                  start, end);
 931         if (ret)
 932                 goto out;
 933
 934         start = end;
 935         end = SVE_PT_SVE_FPSR_OFFSET(vq);
 936         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 937                                         start, end);
 938         if (ret)
 939                 goto out;
 940
 941         /*
 942          * Copy fpsr, and fpcr which must follow contiguously in
 943          * struct fpsimd_state:
 944          */
 945         start = end;
 946         end = SVE_PT_SVE_FPCR_OFFSET(vq) + SVE_PT_SVE_FPCR_SIZE;
 947         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 948                                  &target->thread.uw.fpsimd_state.fpsr,
 949                                  start, end);
 950
 951 out:
 952         fpsimd_flush_task_state(target);
 953         return ret;
 954 }
 955
 956 #endif /* CONFIG_ARM64_SVE */
 957
 958 enum aarch64_regset {
 959         REGSET_GPR,
 960         REGSET_FPR,
 961         REGSET_TLS,
 962 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 963         REGSET_HW_BREAK,
 964         REGSET_HW_WATCH,
 965 #endif
 966         REGSET_SYSTEM_CALL,
 967 #ifdef CONFIG_ARM64_SVE
 968         REGSET_SVE,
 969 #endif
 970 };
 971
 972 static const struct user_regset aarch64_regsets[] = {
 973         [REGSET_GPR] = {
 974                 .core_note_type = NT_PRSTATUS,
 975                 .n = sizeof(struct user_pt_regs) / sizeof(u64),
 976                 .size = sizeof(u64),
 977                 .align = sizeof(u64),
 978                 .get = gpr_get,
 979                 .set = gpr_set
 980         },
 981         [REGSET_FPR] = {
 982                 .core_note_type = NT_PRFPREG,
 983                 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
 984                 /*
 985                  * We pretend we have 32-bit registers because the fpsr and
 986                  * fpcr are 32-bits wide.
 987                  */
 988                 .size = sizeof(u32),
 989                 .align = sizeof(u32),
 990                 .get = fpr_get,
 991                 .set = fpr_set
 992         },
 993         [REGSET_TLS] = {
 994                 .core_note_type = NT_ARM_TLS,
 995                 .n = 1,
 996                 .size = sizeof(void *),
 997                 .align = sizeof(void *),
 998                 .get = tls_get,
 999                 .set = tls_set,
1000         },
1001 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1002         [REGSET_HW_BREAK] = {
1003                 .core_note_type = NT_ARM_HW_BREAK,
1004                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1005                 .size = sizeof(u32),
1006                 .align = sizeof(u32),
1007                 .get = hw_break_get,
1008                 .set = hw_break_set,
1009         },
1010         [REGSET_HW_WATCH] = {
1011                 .core_note_type = NT_ARM_HW_WATCH,
1012                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1013                 .size = sizeof(u32),
1014                 .align = sizeof(u32),
1015                 .get = hw_break_get,
1016                 .set = hw_break_set,
1017         },
1018 #endif
1019         [REGSET_SYSTEM_CALL] = {
1020                 .core_note_type = NT_ARM_SYSTEM_CALL,
1021                 .n = 1,
1022                 .size = sizeof(int),
1023                 .align = sizeof(int),
1024                 .get = system_call_get,
1025                 .set = system_call_set,
1026         },
1027 #ifdef CONFIG_ARM64_SVE
1028         [REGSET_SVE] = { /* Scalable Vector Extension */
1029                 .core_note_type = NT_ARM_SVE,
1030                 .n = DIV_ROUND_UP(SVE_PT_SIZE(SVE_VQ_MAX, SVE_PT_REGS_SVE),
1031                                   SVE_VQ_BYTES),
1032                 .size = SVE_VQ_BYTES,
1033                 .align = SVE_VQ_BYTES,
1034                 .get = sve_get,
1035                 .set = sve_set,
1036                 .get_size = sve_get_size,
1037         },
1038 #endif
1039 };
1040
1041 static const struct user_regset_view user_aarch64_view = {
1042         .name = "aarch64", .e_machine = EM_AARCH64,
1043         .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
1044 };
1045
1046 #ifdef CONFIG_COMPAT
1047 enum compat_regset {
1048         REGSET_COMPAT_GPR,
1049         REGSET_COMPAT_VFP,
1050 };
1051
1052 static int compat_gpr_get(struct task_struct *target,
1053                           const struct user_regset *regset,
1054                           unsigned int pos, unsigned int count,
1055                           void *kbuf, void __user *ubuf)
1056 {
1057         int ret = 0;
1058         unsigned int i, start, num_regs;
1059
1060         /* Calculate the number of AArch32 registers contained in count */
1061         num_regs = count / regset->size;
1062
1063         /* Convert pos into an register number */
1064         start = pos / regset->size;
1065
1066         if (start + num_regs > regset->n)
1067                 return -EIO;
1068
1069         for (i = 0; i < num_regs; ++i) {
1070                 unsigned int idx = start + i;
1071                 compat_ulong_t reg;
1072
1073                 switch (idx) {
1074                 case 15:
1075                         reg = task_pt_regs(target)->pc;
1076                         break;
1077                 case 16:
1078                         reg = task_pt_regs(target)->pstate;
1079                         reg = pstate_to_compat_psr(reg);
1080                         break;
1081                 case 17:
1082                         reg = task_pt_regs(target)->orig_x0;
1083                         break;
1084                 default:
1085                         reg = task_pt_regs(target)->regs[idx];
1086                 }
1087
1088                 if (kbuf) {
1089                         memcpy(kbuf, &reg, sizeof(reg));
1090                         kbuf += sizeof(reg);
1091                 } else {
1092                         ret = copy_to_user(ubuf, &reg, sizeof(reg));
1093                         if (ret) {
1094                                 ret = -EFAULT;
1095                                 break;
1096                         }
1097
1098                         ubuf += sizeof(reg);
1099                 }
1100         }
1101
1102         return ret;
1103 }
1104
1105 static int compat_gpr_set(struct task_struct *target,
1106                           const struct user_regset *regset,
1107                           unsigned int pos, unsigned int count,
1108                           const void *kbuf, const void __user *ubuf)
1109 {
1110         struct pt_regs newregs;
1111         int ret = 0;
1112         unsigned int i, start, num_regs;
1113
1114         /* Calculate the number of AArch32 registers contained in count */
1115         num_regs = count / regset->size;
1116
1117         /* Convert pos into an register number */
1118         start = pos / regset->size;
1119
1120         if (start + num_regs > regset->n)
1121                 return -EIO;
1122
1123         newregs = *task_pt_regs(target);
1124
1125         for (i = 0; i < num_regs; ++i) {
1126                 unsigned int idx = start + i;
1127                 compat_ulong_t reg;
1128
1129                 if (kbuf) {
1130                         memcpy(&reg, kbuf, sizeof(reg));
1131                         kbuf += sizeof(reg);
1132                 } else {
1133                         ret = copy_from_user(&reg, ubuf, sizeof(reg));
1134                         if (ret) {
1135                                 ret = -EFAULT;
1136                                 break;
1137                         }
1138
1139                         ubuf += sizeof(reg);
1140                 }
1141
1142                 switch (idx) {
1143                 case 15:
1144                         newregs.pc = reg;
1145                         break;
1146                 case 16:
1147                         reg = compat_psr_to_pstate(reg);
1148                         newregs.pstate = reg;
1149                         break;
1150                 case 17:
1151                         newregs.orig_x0 = reg;
1152                         break;
1153                 default:
1154                         newregs.regs[idx] = reg;
1155                 }
1156
1157         }
1158
1159         if (valid_user_regs(&newregs.user_regs, target))
1160                 *task_pt_regs(target) = newregs;
1161         else
1162                 ret = -EINVAL;
1163
1164         return ret;
1165 }
1166
1167 static int compat_vfp_get(struct task_struct *target,
1168                           const struct user_regset *regset,
1169                           unsigned int pos, unsigned int count,
1170                           void *kbuf, void __user *ubuf)
1171 {
1172         struct user_fpsimd_state *uregs;
1173         compat_ulong_t fpscr;
1174         int ret, vregs_end_pos;
1175
1176         uregs = &target->thread.uw.fpsimd_state;
1177
1178         if (target == current)
1179                 fpsimd_preserve_current_state();
1180
1181         /*
1182          * The VFP registers are packed into the fpsimd_state, so they all sit
1183          * nicely together for us. We just need to create the fpscr separately.
1184          */
1185         vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t);
1186         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs,
1187                                   0, vregs_end_pos);
1188
1189         if (count && !ret) {
1190                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
1191                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
1192
1193                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &fpscr,
1194                                           vregs_end_pos, VFP_STATE_SIZE);
1195         }
1196
1197         return ret;
1198 }
1199
1200 static int compat_vfp_set(struct task_struct *target,
1201                           const struct user_regset *regset,
1202                           unsigned int pos, unsigned int count,
1203                           const void *kbuf, const void __user *ubuf)
1204 {
1205         struct user_fpsimd_state *uregs;
1206         compat_ulong_t fpscr;
1207         int ret, vregs_end_pos;
1208
1209         uregs = &target->thread.uw.fpsimd_state;
1210
1211         vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t);
1212         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
1213                                  vregs_end_pos);
1214
1215         if (count && !ret) {
1216                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpscr,
1217                                          vregs_end_pos, VFP_STATE_SIZE);
1218                 if (!ret) {
1219                         uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
1220                         uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
1221                 }
1222         }
1223
1224         fpsimd_flush_task_state(target);
1225         return ret;
1226 }
1227
1228 static int compat_tls_get(struct task_struct *target,
1229                           const struct user_regset *regset, unsigned int pos,
1230                           unsigned int count, void *kbuf, void __user *ubuf)
1231 {
1232         compat_ulong_t tls = (compat_ulong_t)target->thread.uw.tp_value;
1233         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
1234 }
1235
1236 static int compat_tls_set(struct task_struct *target,
1237                           const struct user_regset *regset, unsigned int pos,
1238                           unsigned int count, const void *kbuf,
1239                           const void __user *ubuf)
1240 {
1241         int ret;
1242         compat_ulong_t tls = target->thread.uw.tp_value;
1243
1244         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
1245         if (ret)
1246                 return ret;
1247
1248         target->thread.uw.tp_value = tls;
1249         return ret;
1250 }
1251
1252 static const struct user_regset aarch32_regsets[] = {
1253         [REGSET_COMPAT_GPR] = {
1254                 .core_note_type = NT_PRSTATUS,
1255                 .n = COMPAT_ELF_NGREG,
1256                 .size = sizeof(compat_elf_greg_t),
1257                 .align = sizeof(compat_elf_greg_t),
1258                 .get = compat_gpr_get,
1259                 .set = compat_gpr_set
1260         },
1261         [REGSET_COMPAT_VFP] = {
1262                 .core_note_type = NT_ARM_VFP,
1263                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
1264                 .size = sizeof(compat_ulong_t),
1265                 .align = sizeof(compat_ulong_t),
1266                 .get = compat_vfp_get,
1267                 .set = compat_vfp_set
1268         },
1269 };
1270
1271 static const struct user_regset_view user_aarch32_view = {
1272         .name = "aarch32", .e_machine = EM_ARM,
1273         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
1274 };
1275
1276 static const struct user_regset aarch32_ptrace_regsets[] = {
1277         [REGSET_GPR] = {
1278                 .core_note_type = NT_PRSTATUS,
1279                 .n = COMPAT_ELF_NGREG,
1280                 .size = sizeof(compat_elf_greg_t),
1281                 .align = sizeof(compat_elf_greg_t),
1282                 .get = compat_gpr_get,
1283                 .set = compat_gpr_set
1284         },
1285         [REGSET_FPR] = {
1286                 .core_note_type = NT_ARM_VFP,
1287                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
1288                 .size = sizeof(compat_ulong_t),
1289                 .align = sizeof(compat_ulong_t),
1290                 .get = compat_vfp_get,
1291                 .set = compat_vfp_set
1292         },
1293         [REGSET_TLS] = {
1294                 .core_note_type = NT_ARM_TLS,
1295                 .n = 1,
1296                 .size = sizeof(compat_ulong_t),
1297                 .align = sizeof(compat_ulong_t),
1298                 .get = compat_tls_get,
1299                 .set = compat_tls_set,
1300         },
1301 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1302         [REGSET_HW_BREAK] = {
1303                 .core_note_type = NT_ARM_HW_BREAK,
1304                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1305                 .size = sizeof(u32),
1306                 .align = sizeof(u32),
1307                 .get = hw_break_get,
1308                 .set = hw_break_set,
1309         },
1310         [REGSET_HW_WATCH] = {
1311                 .core_note_type = NT_ARM_HW_WATCH,
1312                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1313                 .size = sizeof(u32),
1314                 .align = sizeof(u32),
1315                 .get = hw_break_get,
1316                 .set = hw_break_set,
1317         },
1318 #endif
1319         [REGSET_SYSTEM_CALL] = {
1320                 .core_note_type = NT_ARM_SYSTEM_CALL,
1321                 .n = 1,
1322                 .size = sizeof(int),
1323                 .align = sizeof(int),
1324                 .get = system_call_get,
1325                 .set = system_call_set,
1326         },
1327 };
1328
1329 static const struct user_regset_view user_aarch32_ptrace_view = {
1330         .name = "aarch32", .e_machine = EM_ARM,
1331         .regsets = aarch32_ptrace_regsets, .n = ARRAY_SIZE(aarch32_ptrace_regsets)
1332 };
1333
1334 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
1335                                    compat_ulong_t __user *ret)
1336 {
1337         compat_ulong_t tmp;
1338
1339         if (off & 3)
1340                 return -EIO;
1341
1342         if (off == COMPAT_PT_TEXT_ADDR)
1343                 tmp = tsk->mm->start_code;
1344         else if (off == COMPAT_PT_DATA_ADDR)
1345                 tmp = tsk->mm->start_data;
1346         else if (off == COMPAT_PT_TEXT_END_ADDR)
1347                 tmp = tsk->mm->end_code;
1348         else if (off < sizeof(compat_elf_gregset_t))
1349                 return copy_regset_to_user(tsk, &user_aarch32_view,
1350                                            REGSET_COMPAT_GPR, off,
1351                                            sizeof(compat_ulong_t), ret);
1352         else if (off >= COMPAT_USER_SZ)
1353                 return -EIO;
1354         else
1355                 tmp = 0;
1356
1357         return put_user(tmp, ret);
1358 }
1359
1360 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
1361                                     compat_ulong_t val)
1362 {
1363         int ret;
1364         mm_segment_t old_fs = get_fs();
1365
1366         if (off & 3 || off >= COMPAT_USER_SZ)
1367                 return -EIO;
1368
1369         if (off >= sizeof(compat_elf_gregset_t))
1370                 return 0;
1371
1372         set_fs(KERNEL_DS);
1373         ret = copy_regset_from_user(tsk, &user_aarch32_view,
1374                                     REGSET_COMPAT_GPR, off,
1375                                     sizeof(compat_ulong_t),
1376                                     &val);
1377         set_fs(old_fs);
1378
1379         return ret;
1380 }
1381
1382 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1383
1384 /*
1385  * Convert a virtual register number into an index for a thread_info
1386  * breakpoint array. Breakpoints are identified using positive numbers
1387  * whilst watchpoints are negative. The registers are laid out as pairs
1388  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
1389  * Register 0 is reserved for describing resource information.
1390  */
1391 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
1392 {
1393         return (abs(num) - 1) >> 1;
1394 }
1395
1396 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
1397 {
1398         u8 num_brps, num_wrps, debug_arch, wp_len;
1399         u32 reg = 0;
1400
1401         num_brps        = hw_breakpoint_slots(TYPE_INST);
1402         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
1403
1404         debug_arch      = debug_monitors_arch();
1405         wp_len          = 8;
1406         reg             |= debug_arch;
1407         reg             <<= 8;
1408         reg             |= wp_len;
1409         reg             <<= 8;
1410         reg             |= num_wrps;
1411         reg             <<= 8;
1412         reg             |= num_brps;
1413
1414         *kdata = reg;
1415         return 0;
1416 }
1417
1418 static int compat_ptrace_hbp_get(unsigned int note_type,
1419                                  struct task_struct *tsk,
1420                                  compat_long_t num,
1421                                  u32 *kdata)
1422 {
1423         u64 addr = 0;
1424         u32 ctrl = 0;
1425
1426         int err, idx = compat_ptrace_hbp_num_to_idx(num);
1427
1428         if (num & 1) {
1429                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
1430                 *kdata = (u32)addr;
1431         } else {
1432                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
1433                 *kdata = ctrl;
1434         }
1435
1436         return err;
1437 }
1438
1439 static int compat_ptrace_hbp_set(unsigned int note_type,
1440                                  struct task_struct *tsk,
1441                                  compat_long_t num,
1442                                  u32 *kdata)
1443 {
1444         u64 addr;
1445         u32 ctrl;
1446
1447         int err, idx = compat_ptrace_hbp_num_to_idx(num);
1448
1449         if (num & 1) {
1450                 addr = *kdata;
1451                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
1452         } else {
1453                 ctrl = *kdata;
1454                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
1455         }
1456
1457         return err;
1458 }
1459
1460 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
1461                                     compat_ulong_t __user *data)
1462 {
1463         int ret;
1464         u32 kdata;
1465
1466         /* Watchpoint */
1467         if (num < 0) {
1468                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
1469         /* Resource info */
1470         } else if (num == 0) {
1471                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
1472         /* Breakpoint */
1473         } else {
1474                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
1475         }
1476
1477         if (!ret)
1478                 ret = put_user(kdata, data);
1479
1480         return ret;
1481 }
1482
1483 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
1484                                     compat_ulong_t __user *data)
1485 {
1486         int ret;
1487         u32 kdata = 0;
1488
1489         if (num == 0)
1490                 return 0;
1491
1492         ret = get_user(kdata, data);
1493         if (ret)
1494                 return ret;
1495
1496         if (num < 0)
1497                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
1498         else
1499                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
1500
1501         return ret;
1502 }
1503 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
1504
1505 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1506                         compat_ulong_t caddr, compat_ulong_t cdata)
1507 {
1508         unsigned long addr = caddr;
1509         unsigned long data = cdata;
1510         void __user *datap = compat_ptr(data);
1511         int ret;
1512
1513         switch (request) {
1514                 case PTRACE_PEEKUSR:
1515                         ret = compat_ptrace_read_user(child, addr, datap);
1516                         break;
1517
1518                 case PTRACE_POKEUSR:
1519                         ret = compat_ptrace_write_user(child, addr, data);
1520                         break;
1521
1522                 case COMPAT_PTRACE_GETREGS:
1523                         ret = copy_regset_to_user(child,
1524                                                   &user_aarch32_view,
1525                                                   REGSET_COMPAT_GPR,
1526                                                   0, sizeof(compat_elf_gregset_t),
1527                                                   datap);
1528                         break;
1529
1530                 case COMPAT_PTRACE_SETREGS:
1531                         ret = copy_regset_from_user(child,
1532                                                     &user_aarch32_view,
1533                                                     REGSET_COMPAT_GPR,
1534                                                     0, sizeof(compat_elf_gregset_t),
1535                                                     datap);
1536                         break;
1537
1538                 case COMPAT_PTRACE_GET_THREAD_AREA:
1539                         ret = put_user((compat_ulong_t)child->thread.uw.tp_value,
1540                                        (compat_ulong_t __user *)datap);
1541                         break;
1542
1543                 case COMPAT_PTRACE_SET_SYSCALL:
1544                         task_pt_regs(child)->syscallno = data;
1545                         ret = 0;
1546                         break;
1547
1548                 case COMPAT_PTRACE_GETVFPREGS:
1549                         ret = copy_regset_to_user(child,
1550                                                   &user_aarch32_view,
1551                                                   REGSET_COMPAT_VFP,
1552                                                   0, VFP_STATE_SIZE,
1553                                                   datap);
1554                         break;
1555
1556                 case COMPAT_PTRACE_SETVFPREGS:
1557                         ret = copy_regset_from_user(child,
1558                                                     &user_aarch32_view,
1559                                                     REGSET_COMPAT_VFP,
1560                                                     0, VFP_STATE_SIZE,
1561                                                     datap);
1562                         break;
1563
1564 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1565                 case COMPAT_PTRACE_GETHBPREGS:
1566                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1567                         break;
1568
1569                 case COMPAT_PTRACE_SETHBPREGS:
1570                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1571                         break;
1572 #endif
1573
1574                 default:
1575                         ret = compat_ptrace_request(child, request, addr,
1576                                                     data);
1577                         break;
1578         }
1579
1580         return ret;
1581 }
1582 #endif /* CONFIG_COMPAT */
1583
1584 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1585 {
1586 #ifdef CONFIG_COMPAT
1587         /*
1588          * Core dumping of 32-bit tasks or compat ptrace requests must use the
1589          * user_aarch32_view compatible with arm32. Native ptrace requests on
1590          * 32-bit children use an extended user_aarch32_ptrace_view to allow
1591          * access to the TLS register.
1592          */
1593         if (is_compat_task())
1594                 return &user_aarch32_view;
1595         else if (is_compat_thread(task_thread_info(task)))
1596                 return &user_aarch32_ptrace_view;
1597 #endif
1598         return &user_aarch64_view;
1599 }
1600
1601 long arch_ptrace(struct task_struct *child, long request,
1602                  unsigned long addr, unsigned long data)
1603 {
1604         return ptrace_request(child, request, addr, data);
1605 }
1606
1607 enum ptrace_syscall_dir {
1608         PTRACE_SYSCALL_ENTER = 0,
1609         PTRACE_SYSCALL_EXIT,
1610 };
1611
1612 static void tracehook_report_syscall(struct pt_regs *regs,
1613                                      enum ptrace_syscall_dir dir)
1614 {
1615         int regno;
1616         unsigned long saved_reg;
1617
1618         /*
1619          * A scratch register (ip(r12) on AArch32, x7 on AArch64) is
1620          * used to denote syscall entry/exit:
1621          */
1622         regno = (is_compat_task() ? 12 : 7);
1623         saved_reg = regs->regs[regno];
1624         regs->regs[regno] = dir;
1625
1626         if (dir == PTRACE_SYSCALL_EXIT)
1627                 tracehook_report_syscall_exit(regs, 0);
1628         else if (tracehook_report_syscall_entry(regs))
1629                 forget_syscall(regs);
1630
1631         regs->regs[regno] = saved_reg;
1632 }
1633
1634 int syscall_trace_enter(struct pt_regs *regs)
1635 {
1636         if (test_thread_flag(TIF_SYSCALL_TRACE))
1637                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1638
1639         /* Do the secure computing after ptrace; failures should be fast. */
1640         if (secure_computing(NULL) == -1)
1641                 return -1;
1642
1643         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1644                 trace_sys_enter(regs, regs->syscallno);
1645
1646         audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1],
1647                             regs->regs[2], regs->regs[3]);
1648
1649         return regs->syscallno;
1650 }
1651
1652 void syscall_trace_exit(struct pt_regs *regs)
1653 {
1654         audit_syscall_exit(regs);
1655
1656         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1657                 trace_sys_exit(regs, regs_return_value(regs));
1658
1659         if (test_thread_flag(TIF_SYSCALL_TRACE))
1660                 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1661
1662         rseq_syscall(regs);
1663 }
1664
1665 /*
1666  * SPSR_ELx bits which are always architecturally RES0 per ARM DDI 0487C.a
1667  * We also take into account DIT (bit 24), which is not yet documented, and
1668  * treat PAN and UAO as RES0 bits, as they are meaningless at EL0, and may be
1669  * allocated an EL0 meaning in future.
1670  * Userspace cannot use these until they have an architectural meaning.
1671  * Note that this follows the SPSR_ELx format, not the AArch32 PSR format.
1672  * We also reserve IL for the kernel; SS is handled dynamically.
1673  */
1674 #define SPSR_EL1_AARCH64_RES0_BITS \
1675         (GENMASK_ULL(63,32) | GENMASK_ULL(27, 25) | GENMASK_ULL(23, 22) | \
1676          GENMASK_ULL(20, 10) | GENMASK_ULL(5, 5))
1677 #define SPSR_EL1_AARCH32_RES0_BITS \
1678         (GENMASK_ULL(63,32) | GENMASK_ULL(23, 22) | GENMASK_ULL(20,20))
1679
1680 static int valid_compat_regs(struct user_pt_regs *regs)
1681 {
1682         regs->pstate &= ~SPSR_EL1_AARCH32_RES0_BITS;
1683
1684         if (!system_supports_mixed_endian_el0()) {
1685                 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
1686                         regs->pstate |= PSR_AA32_E_BIT;
1687                 else
1688                         regs->pstate &= ~PSR_AA32_E_BIT;
1689         }
1690
1691         if (user_mode(regs) && (regs->pstate & PSR_MODE32_BIT) &&
1692             (regs->pstate & PSR_AA32_A_BIT) == 0 &&
1693             (regs->pstate & PSR_AA32_I_BIT) == 0 &&
1694             (regs->pstate & PSR_AA32_F_BIT) == 0) {
1695                 return 1;
1696         }
1697
1698         /*
1699          * Force PSR to a valid 32-bit EL0t, preserving the same bits as
1700          * arch/arm.
1701          */
1702         regs->pstate &= PSR_AA32_N_BIT | PSR_AA32_Z_BIT |
1703                         PSR_AA32_C_BIT | PSR_AA32_V_BIT |
1704                         PSR_AA32_Q_BIT | PSR_AA32_IT_MASK |
1705                         PSR_AA32_GE_MASK | PSR_AA32_E_BIT |
1706                         PSR_AA32_T_BIT;
1707         regs->pstate |= PSR_MODE32_BIT;
1708
1709         return 0;
1710 }
1711
1712 static int valid_native_regs(struct user_pt_regs *regs)
1713 {
1714         regs->pstate &= ~SPSR_EL1_AARCH64_RES0_BITS;
1715
1716         if (user_mode(regs) && !(regs->pstate & PSR_MODE32_BIT) &&
1717             (regs->pstate & PSR_D_BIT) == 0 &&
1718             (regs->pstate & PSR_A_BIT) == 0 &&
1719             (regs->pstate & PSR_I_BIT) == 0 &&
1720             (regs->pstate & PSR_F_BIT) == 0) {
1721                 return 1;
1722         }
1723
1724         /* Force PSR to a valid 64-bit EL0t */
1725         regs->pstate &= PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT;
1726
1727         return 0;
1728 }
1729
1730 /*
1731  * Are the current registers suitable for user mode? (used to maintain
1732  * security in signal handlers)
1733  */
1734 int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task)
1735 {
1736         if (!test_tsk_thread_flag(task, TIF_SINGLESTEP))
1737                 regs->pstate &= ~DBG_SPSR_SS;
1738
1739         if (is_compat_thread(task_thread_info(task)))
1740                 return valid_compat_regs(regs);
1741         else
1742                 return valid_native_regs(regs);
1743 }