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