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                         break;
1080                 case 17:
1081                         reg = task_pt_regs(target)->orig_x0;
1082                         break;
1083                 default:
1084                         reg = task_pt_regs(target)->regs[idx];
1085                 }
1086
1087                 if (kbuf) {
1088                         memcpy(kbuf, &reg, sizeof(reg));
1089                         kbuf += sizeof(reg);
1090                 } else {
1091                         ret = copy_to_user(ubuf, &reg, sizeof(reg));
1092                         if (ret) {
1093                                 ret = -EFAULT;
1094                                 break;
1095                         }
1096
1097                         ubuf += sizeof(reg);
1098                 }
1099         }
1100
1101         return ret;
1102 }
1103
1104 static int compat_gpr_set(struct task_struct *target,
1105                           const struct user_regset *regset,
1106                           unsigned int pos, unsigned int count,
1107                           const void *kbuf, const void __user *ubuf)
1108 {
1109         struct pt_regs newregs;
1110         int ret = 0;
1111         unsigned int i, start, num_regs;
1112
1113         /* Calculate the number of AArch32 registers contained in count */
1114         num_regs = count / regset->size;
1115
1116         /* Convert pos into an register number */
1117         start = pos / regset->size;
1118
1119         if (start + num_regs > regset->n)
1120                 return -EIO;
1121
1122         newregs = *task_pt_regs(target);
1123
1124         for (i = 0; i < num_regs; ++i) {
1125                 unsigned int idx = start + i;
1126                 compat_ulong_t reg;
1127
1128                 if (kbuf) {
1129                         memcpy(&reg, kbuf, sizeof(reg));
1130                         kbuf += sizeof(reg);
1131                 } else {
1132                         ret = copy_from_user(&reg, ubuf, sizeof(reg));
1133                         if (ret) {
1134                                 ret = -EFAULT;
1135                                 break;
1136                         }
1137
1138                         ubuf += sizeof(reg);
1139                 }
1140
1141                 switch (idx) {
1142                 case 15:
1143                         newregs.pc = reg;
1144                         break;
1145                 case 16:
1146                         newregs.pstate = reg;
1147                         break;
1148                 case 17:
1149                         newregs.orig_x0 = reg;
1150                         break;
1151                 default:
1152                         newregs.regs[idx] = reg;
1153                 }
1154
1155         }
1156
1157         if (valid_user_regs(&newregs.user_regs, target))
1158                 *task_pt_regs(target) = newregs;
1159         else
1160                 ret = -EINVAL;
1161
1162         return ret;
1163 }
1164
1165 static int compat_vfp_get(struct task_struct *target,
1166                           const struct user_regset *regset,
1167                           unsigned int pos, unsigned int count,
1168                           void *kbuf, void __user *ubuf)
1169 {
1170         struct user_fpsimd_state *uregs;
1171         compat_ulong_t fpscr;
1172         int ret, vregs_end_pos;
1173
1174         uregs = &target->thread.uw.fpsimd_state;
1175
1176         if (target == current)
1177                 fpsimd_preserve_current_state();
1178
1179         /*
1180          * The VFP registers are packed into the fpsimd_state, so they all sit
1181          * nicely together for us. We just need to create the fpscr separately.
1182          */
1183         vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t);
1184         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs,
1185                                   0, vregs_end_pos);
1186
1187         if (count && !ret) {
1188                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
1189                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
1190
1191                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &fpscr,
1192                                           vregs_end_pos, VFP_STATE_SIZE);
1193         }
1194
1195         return ret;
1196 }
1197
1198 static int compat_vfp_set(struct task_struct *target,
1199                           const struct user_regset *regset,
1200                           unsigned int pos, unsigned int count,
1201                           const void *kbuf, const void __user *ubuf)
1202 {
1203         struct user_fpsimd_state *uregs;
1204         compat_ulong_t fpscr;
1205         int ret, vregs_end_pos;
1206
1207         uregs = &target->thread.uw.fpsimd_state;
1208
1209         vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t);
1210         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
1211                                  vregs_end_pos);
1212
1213         if (count && !ret) {
1214                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpscr,
1215                                          vregs_end_pos, VFP_STATE_SIZE);
1216                 if (!ret) {
1217                         uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
1218                         uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
1219                 }
1220         }
1221
1222         fpsimd_flush_task_state(target);
1223         return ret;
1224 }
1225
1226 static int compat_tls_get(struct task_struct *target,
1227                           const struct user_regset *regset, unsigned int pos,
1228                           unsigned int count, void *kbuf, void __user *ubuf)
1229 {
1230         compat_ulong_t tls = (compat_ulong_t)target->thread.uw.tp_value;
1231         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
1232 }
1233
1234 static int compat_tls_set(struct task_struct *target,
1235                           const struct user_regset *regset, unsigned int pos,
1236                           unsigned int count, const void *kbuf,
1237                           const void __user *ubuf)
1238 {
1239         int ret;
1240         compat_ulong_t tls = target->thread.uw.tp_value;
1241
1242         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
1243         if (ret)
1244                 return ret;
1245
1246         target->thread.uw.tp_value = tls;
1247         return ret;
1248 }
1249
1250 static const struct user_regset aarch32_regsets[] = {
1251         [REGSET_COMPAT_GPR] = {
1252                 .core_note_type = NT_PRSTATUS,
1253                 .n = COMPAT_ELF_NGREG,
1254                 .size = sizeof(compat_elf_greg_t),
1255                 .align = sizeof(compat_elf_greg_t),
1256                 .get = compat_gpr_get,
1257                 .set = compat_gpr_set
1258         },
1259         [REGSET_COMPAT_VFP] = {
1260                 .core_note_type = NT_ARM_VFP,
1261                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
1262                 .size = sizeof(compat_ulong_t),
1263                 .align = sizeof(compat_ulong_t),
1264                 .get = compat_vfp_get,
1265                 .set = compat_vfp_set
1266         },
1267 };
1268
1269 static const struct user_regset_view user_aarch32_view = {
1270         .name = "aarch32", .e_machine = EM_ARM,
1271         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
1272 };
1273
1274 static const struct user_regset aarch32_ptrace_regsets[] = {
1275         [REGSET_GPR] = {
1276                 .core_note_type = NT_PRSTATUS,
1277                 .n = COMPAT_ELF_NGREG,
1278                 .size = sizeof(compat_elf_greg_t),
1279                 .align = sizeof(compat_elf_greg_t),
1280                 .get = compat_gpr_get,
1281                 .set = compat_gpr_set
1282         },
1283         [REGSET_FPR] = {
1284                 .core_note_type = NT_ARM_VFP,
1285                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
1286                 .size = sizeof(compat_ulong_t),
1287                 .align = sizeof(compat_ulong_t),
1288                 .get = compat_vfp_get,
1289                 .set = compat_vfp_set
1290         },
1291         [REGSET_TLS] = {
1292                 .core_note_type = NT_ARM_TLS,
1293                 .n = 1,
1294                 .size = sizeof(compat_ulong_t),
1295                 .align = sizeof(compat_ulong_t),
1296                 .get = compat_tls_get,
1297                 .set = compat_tls_set,
1298         },
1299 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1300         [REGSET_HW_BREAK] = {
1301                 .core_note_type = NT_ARM_HW_BREAK,
1302                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1303                 .size = sizeof(u32),
1304                 .align = sizeof(u32),
1305                 .get = hw_break_get,
1306                 .set = hw_break_set,
1307         },
1308         [REGSET_HW_WATCH] = {
1309                 .core_note_type = NT_ARM_HW_WATCH,
1310                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
1311                 .size = sizeof(u32),
1312                 .align = sizeof(u32),
1313                 .get = hw_break_get,
1314                 .set = hw_break_set,
1315         },
1316 #endif
1317         [REGSET_SYSTEM_CALL] = {
1318                 .core_note_type = NT_ARM_SYSTEM_CALL,
1319                 .n = 1,
1320                 .size = sizeof(int),
1321                 .align = sizeof(int),
1322                 .get = system_call_get,
1323                 .set = system_call_set,
1324         },
1325 };
1326
1327 static const struct user_regset_view user_aarch32_ptrace_view = {
1328         .name = "aarch32", .e_machine = EM_ARM,
1329         .regsets = aarch32_ptrace_regsets, .n = ARRAY_SIZE(aarch32_ptrace_regsets)
1330 };
1331
1332 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
1333                                    compat_ulong_t __user *ret)
1334 {
1335         compat_ulong_t tmp;
1336
1337         if (off & 3)
1338                 return -EIO;
1339
1340         if (off == COMPAT_PT_TEXT_ADDR)
1341                 tmp = tsk->mm->start_code;
1342         else if (off == COMPAT_PT_DATA_ADDR)
1343                 tmp = tsk->mm->start_data;
1344         else if (off == COMPAT_PT_TEXT_END_ADDR)
1345                 tmp = tsk->mm->end_code;
1346         else if (off < sizeof(compat_elf_gregset_t))
1347                 return copy_regset_to_user(tsk, &user_aarch32_view,
1348                                            REGSET_COMPAT_GPR, off,
1349                                            sizeof(compat_ulong_t), ret);
1350         else if (off >= COMPAT_USER_SZ)
1351                 return -EIO;
1352         else
1353                 tmp = 0;
1354
1355         return put_user(tmp, ret);
1356 }
1357
1358 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
1359                                     compat_ulong_t val)
1360 {
1361         int ret;
1362         mm_segment_t old_fs = get_fs();
1363
1364         if (off & 3 || off >= COMPAT_USER_SZ)
1365                 return -EIO;
1366
1367         if (off >= sizeof(compat_elf_gregset_t))
1368                 return 0;
1369
1370         set_fs(KERNEL_DS);
1371         ret = copy_regset_from_user(tsk, &user_aarch32_view,
1372                                     REGSET_COMPAT_GPR, off,
1373                                     sizeof(compat_ulong_t),
1374                                     &val);
1375         set_fs(old_fs);
1376
1377         return ret;
1378 }
1379
1380 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1381
1382 /*
1383  * Convert a virtual register number into an index for a thread_info
1384  * breakpoint array. Breakpoints are identified using positive numbers
1385  * whilst watchpoints are negative. The registers are laid out as pairs
1386  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
1387  * Register 0 is reserved for describing resource information.
1388  */
1389 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
1390 {
1391         return (abs(num) - 1) >> 1;
1392 }
1393
1394 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
1395 {
1396         u8 num_brps, num_wrps, debug_arch, wp_len;
1397         u32 reg = 0;
1398
1399         num_brps        = hw_breakpoint_slots(TYPE_INST);
1400         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
1401
1402         debug_arch      = debug_monitors_arch();
1403         wp_len          = 8;
1404         reg             |= debug_arch;
1405         reg             <<= 8;
1406         reg             |= wp_len;
1407         reg             <<= 8;
1408         reg             |= num_wrps;
1409         reg             <<= 8;
1410         reg             |= num_brps;
1411
1412         *kdata = reg;
1413         return 0;
1414 }
1415
1416 static int compat_ptrace_hbp_get(unsigned int note_type,
1417                                  struct task_struct *tsk,
1418                                  compat_long_t num,
1419                                  u32 *kdata)
1420 {
1421         u64 addr = 0;
1422         u32 ctrl = 0;
1423
1424         int err, idx = compat_ptrace_hbp_num_to_idx(num);
1425
1426         if (num & 1) {
1427                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
1428                 *kdata = (u32)addr;
1429         } else {
1430                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
1431                 *kdata = ctrl;
1432         }
1433
1434         return err;
1435 }
1436
1437 static int compat_ptrace_hbp_set(unsigned int note_type,
1438                                  struct task_struct *tsk,
1439                                  compat_long_t num,
1440                                  u32 *kdata)
1441 {
1442         u64 addr;
1443         u32 ctrl;
1444
1445         int err, idx = compat_ptrace_hbp_num_to_idx(num);
1446
1447         if (num & 1) {
1448                 addr = *kdata;
1449                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
1450         } else {
1451                 ctrl = *kdata;
1452                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
1453         }
1454
1455         return err;
1456 }
1457
1458 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
1459                                     compat_ulong_t __user *data)
1460 {
1461         int ret;
1462         u32 kdata;
1463
1464         /* Watchpoint */
1465         if (num < 0) {
1466                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
1467         /* Resource info */
1468         } else if (num == 0) {
1469                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
1470         /* Breakpoint */
1471         } else {
1472                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
1473         }
1474
1475         if (!ret)
1476                 ret = put_user(kdata, data);
1477
1478         return ret;
1479 }
1480
1481 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
1482                                     compat_ulong_t __user *data)
1483 {
1484         int ret;
1485         u32 kdata = 0;
1486
1487         if (num == 0)
1488                 return 0;
1489
1490         ret = get_user(kdata, data);
1491         if (ret)
1492                 return ret;
1493
1494         if (num < 0)
1495                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
1496         else
1497                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
1498
1499         return ret;
1500 }
1501 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
1502
1503 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1504                         compat_ulong_t caddr, compat_ulong_t cdata)
1505 {
1506         unsigned long addr = caddr;
1507         unsigned long data = cdata;
1508         void __user *datap = compat_ptr(data);
1509         int ret;
1510
1511         switch (request) {
1512                 case PTRACE_PEEKUSR:
1513                         ret = compat_ptrace_read_user(child, addr, datap);
1514                         break;
1515
1516                 case PTRACE_POKEUSR:
1517                         ret = compat_ptrace_write_user(child, addr, data);
1518                         break;
1519
1520                 case COMPAT_PTRACE_GETREGS:
1521                         ret = copy_regset_to_user(child,
1522                                                   &user_aarch32_view,
1523                                                   REGSET_COMPAT_GPR,
1524                                                   0, sizeof(compat_elf_gregset_t),
1525                                                   datap);
1526                         break;
1527
1528                 case COMPAT_PTRACE_SETREGS:
1529                         ret = copy_regset_from_user(child,
1530                                                     &user_aarch32_view,
1531                                                     REGSET_COMPAT_GPR,
1532                                                     0, sizeof(compat_elf_gregset_t),
1533                                                     datap);
1534                         break;
1535
1536                 case COMPAT_PTRACE_GET_THREAD_AREA:
1537                         ret = put_user((compat_ulong_t)child->thread.uw.tp_value,
1538                                        (compat_ulong_t __user *)datap);
1539                         break;
1540
1541                 case COMPAT_PTRACE_SET_SYSCALL:
1542                         task_pt_regs(child)->syscallno = data;
1543                         ret = 0;
1544                         break;
1545
1546                 case COMPAT_PTRACE_GETVFPREGS:
1547                         ret = copy_regset_to_user(child,
1548                                                   &user_aarch32_view,
1549                                                   REGSET_COMPAT_VFP,
1550                                                   0, VFP_STATE_SIZE,
1551                                                   datap);
1552                         break;
1553
1554                 case COMPAT_PTRACE_SETVFPREGS:
1555                         ret = copy_regset_from_user(child,
1556                                                     &user_aarch32_view,
1557                                                     REGSET_COMPAT_VFP,
1558                                                     0, VFP_STATE_SIZE,
1559                                                     datap);
1560                         break;
1561
1562 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1563                 case COMPAT_PTRACE_GETHBPREGS:
1564                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1565                         break;
1566
1567                 case COMPAT_PTRACE_SETHBPREGS:
1568                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1569                         break;
1570 #endif
1571
1572                 default:
1573                         ret = compat_ptrace_request(child, request, addr,
1574                                                     data);
1575                         break;
1576         }
1577
1578         return ret;
1579 }
1580 #endif /* CONFIG_COMPAT */
1581
1582 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1583 {
1584 #ifdef CONFIG_COMPAT
1585         /*
1586          * Core dumping of 32-bit tasks or compat ptrace requests must use the
1587          * user_aarch32_view compatible with arm32. Native ptrace requests on
1588          * 32-bit children use an extended user_aarch32_ptrace_view to allow
1589          * access to the TLS register.
1590          */
1591         if (is_compat_task())
1592                 return &user_aarch32_view;
1593         else if (is_compat_thread(task_thread_info(task)))
1594                 return &user_aarch32_ptrace_view;
1595 #endif
1596         return &user_aarch64_view;
1597 }
1598
1599 long arch_ptrace(struct task_struct *child, long request,
1600                  unsigned long addr, unsigned long data)
1601 {
1602         return ptrace_request(child, request, addr, data);
1603 }
1604
1605 enum ptrace_syscall_dir {
1606         PTRACE_SYSCALL_ENTER = 0,
1607         PTRACE_SYSCALL_EXIT,
1608 };
1609
1610 static void tracehook_report_syscall(struct pt_regs *regs,
1611                                      enum ptrace_syscall_dir dir)
1612 {
1613         int regno;
1614         unsigned long saved_reg;
1615
1616         /*
1617          * A scratch register (ip(r12) on AArch32, x7 on AArch64) is
1618          * used to denote syscall entry/exit:
1619          */
1620         regno = (is_compat_task() ? 12 : 7);
1621         saved_reg = regs->regs[regno];
1622         regs->regs[regno] = dir;
1623
1624         if (dir == PTRACE_SYSCALL_EXIT)
1625                 tracehook_report_syscall_exit(regs, 0);
1626         else if (tracehook_report_syscall_entry(regs))
1627                 forget_syscall(regs);
1628
1629         regs->regs[regno] = saved_reg;
1630 }
1631
1632 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
1633 {
1634         if (test_thread_flag(TIF_SYSCALL_TRACE))
1635                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1636
1637         /* Do the secure computing after ptrace; failures should be fast. */
1638         if (secure_computing(NULL) == -1)
1639                 return -1;
1640
1641         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1642                 trace_sys_enter(regs, regs->syscallno);
1643
1644         audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1],
1645                             regs->regs[2], regs->regs[3]);
1646
1647         return regs->syscallno;
1648 }
1649
1650 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
1651 {
1652         audit_syscall_exit(regs);
1653
1654         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1655                 trace_sys_exit(regs, regs_return_value(regs));
1656
1657         if (test_thread_flag(TIF_SYSCALL_TRACE))
1658                 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1659 }
1660
1661 /*
1662  * Bits which are always architecturally RES0 per ARM DDI 0487A.h
1663  * Userspace cannot use these until they have an architectural meaning.
1664  * We also reserve IL for the kernel; SS is handled dynamically.
1665  */
1666 #define SPSR_EL1_AARCH64_RES0_BITS \
1667         (GENMASK_ULL(63,32) | GENMASK_ULL(27, 22) | GENMASK_ULL(20, 10) | \
1668          GENMASK_ULL(5, 5))
1669 #define SPSR_EL1_AARCH32_RES0_BITS \
1670         (GENMASK_ULL(63,32) | GENMASK_ULL(24, 22) | GENMASK_ULL(20,20))
1671
1672 static int valid_compat_regs(struct user_pt_regs *regs)
1673 {
1674         regs->pstate &= ~SPSR_EL1_AARCH32_RES0_BITS;
1675
1676         if (!system_supports_mixed_endian_el0()) {
1677                 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
1678                         regs->pstate |= COMPAT_PSR_E_BIT;
1679                 else
1680                         regs->pstate &= ~COMPAT_PSR_E_BIT;
1681         }
1682
1683         if (user_mode(regs) && (regs->pstate & PSR_MODE32_BIT) &&
1684             (regs->pstate & COMPAT_PSR_A_BIT) == 0 &&
1685             (regs->pstate & COMPAT_PSR_I_BIT) == 0 &&
1686             (regs->pstate & COMPAT_PSR_F_BIT) == 0) {
1687                 return 1;
1688         }
1689
1690         /*
1691          * Force PSR to a valid 32-bit EL0t, preserving the same bits as
1692          * arch/arm.
1693          */
1694         regs->pstate &= COMPAT_PSR_N_BIT | COMPAT_PSR_Z_BIT |
1695                         COMPAT_PSR_C_BIT | COMPAT_PSR_V_BIT |
1696                         COMPAT_PSR_Q_BIT | COMPAT_PSR_IT_MASK |
1697                         COMPAT_PSR_GE_MASK | COMPAT_PSR_E_BIT |
1698                         COMPAT_PSR_T_BIT;
1699         regs->pstate |= PSR_MODE32_BIT;
1700
1701         return 0;
1702 }
1703
1704 static int valid_native_regs(struct user_pt_regs *regs)
1705 {
1706         regs->pstate &= ~SPSR_EL1_AARCH64_RES0_BITS;
1707
1708         if (user_mode(regs) && !(regs->pstate & PSR_MODE32_BIT) &&
1709             (regs->pstate & PSR_D_BIT) == 0 &&
1710             (regs->pstate & PSR_A_BIT) == 0 &&
1711             (regs->pstate & PSR_I_BIT) == 0 &&
1712             (regs->pstate & PSR_F_BIT) == 0) {
1713                 return 1;
1714         }
1715
1716         /* Force PSR to a valid 64-bit EL0t */
1717         regs->pstate &= PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT;
1718
1719         return 0;
1720 }
1721
1722 /*
1723  * Are the current registers suitable for user mode? (used to maintain
1724  * security in signal handlers)
1725  */
1726 int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task)
1727 {
1728         if (!test_tsk_thread_flag(task, TIF_SINGLESTEP))
1729                 regs->pstate &= ~DBG_SPSR_SS;
1730
1731         if (is_compat_thread(task_thread_info(task)))
1732                 return valid_compat_regs(regs);
1733         else
1734                 return valid_native_regs(regs);
1735 }