arch/x86/kernel/ptrace.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* By Ross Biro 1/23/92 */
   3 /*
   4  * Pentium III FXSR, SSE support
   5  *      Gareth Hughes <gareth@valinux.com>, May 2000
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/sched.h>
  10 #include <linux/sched/task_stack.h>
  11 #include <linux/mm.h>
  12 #include <linux/smp.h>
  13 #include <linux/errno.h>
  14 #include <linux/slab.h>
  15 #include <linux/ptrace.h>
  16 #include <linux/tracehook.h>
  17 #include <linux/user.h>
  18 #include <linux/elf.h>
  19 #include <linux/security.h>
  20 #include <linux/audit.h>
  21 #include <linux/seccomp.h>
  22 #include <linux/signal.h>
  23 #include <linux/perf_event.h>
  24 #include <linux/hw_breakpoint.h>
  25 #include <linux/rcupdate.h>
  26 #include <linux/export.h>
  27 #include <linux/context_tracking.h>
  28 #include <linux/nospec.h>
  29
  30 #include <linux/uaccess.h>
  31 #include <asm/processor.h>
  32 #include <asm/fpu/internal.h>
  33 #include <asm/fpu/signal.h>
  34 #include <asm/fpu/regset.h>
  35 #include <asm/debugreg.h>
  36 #include <asm/ldt.h>
  37 #include <asm/desc.h>
  38 #include <asm/prctl.h>
  39 #include <asm/proto.h>
  40 #include <asm/hw_breakpoint.h>
  41 #include <asm/traps.h>
  42 #include <asm/syscall.h>
  43 #include <asm/fsgsbase.h>
  44 #include <asm/io_bitmap.h>
  45
  46 #include "tls.h"
  47
  48 enum x86_regset {
  49         REGSET_GENERAL,
  50         REGSET_FP,
  51         REGSET_XFP,
  52         REGSET_IOPERM64 = REGSET_XFP,
  53         REGSET_XSTATE,
  54         REGSET_TLS,
  55         REGSET_IOPERM32,
  56 };
  57
  58 struct pt_regs_offset {
  59         const char *name;
  60         int offset;
  61 };
  62
  63 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  64 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  65
  66 static const struct pt_regs_offset regoffset_table[] = {
  67 #ifdef CONFIG_X86_64
  68         REG_OFFSET_NAME(r15),
  69         REG_OFFSET_NAME(r14),
  70         REG_OFFSET_NAME(r13),
  71         REG_OFFSET_NAME(r12),
  72         REG_OFFSET_NAME(r11),
  73         REG_OFFSET_NAME(r10),
  74         REG_OFFSET_NAME(r9),
  75         REG_OFFSET_NAME(r8),
  76 #endif
  77         REG_OFFSET_NAME(bx),
  78         REG_OFFSET_NAME(cx),
  79         REG_OFFSET_NAME(dx),
  80         REG_OFFSET_NAME(si),
  81         REG_OFFSET_NAME(di),
  82         REG_OFFSET_NAME(bp),
  83         REG_OFFSET_NAME(ax),
  84 #ifdef CONFIG_X86_32
  85         REG_OFFSET_NAME(ds),
  86         REG_OFFSET_NAME(es),
  87         REG_OFFSET_NAME(fs),
  88         REG_OFFSET_NAME(gs),
  89 #endif
  90         REG_OFFSET_NAME(orig_ax),
  91         REG_OFFSET_NAME(ip),
  92         REG_OFFSET_NAME(cs),
  93         REG_OFFSET_NAME(flags),
  94         REG_OFFSET_NAME(sp),
  95         REG_OFFSET_NAME(ss),
  96         REG_OFFSET_END,
  97 };
  98
  99 /**
 100  * regs_query_register_offset() - query register offset from its name
 101  * @name:       the name of a register
 102  *
 103  * regs_query_register_offset() returns the offset of a register in struct
 104  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 105  */
 106 int regs_query_register_offset(const char *name)
 107 {
 108         const struct pt_regs_offset *roff;
 109         for (roff = regoffset_table; roff->name != NULL; roff++)
 110                 if (!strcmp(roff->name, name))
 111                         return roff->offset;
 112         return -EINVAL;
 113 }
 114
 115 /**
 116  * regs_query_register_name() - query register name from its offset
 117  * @offset:     the offset of a register in struct pt_regs.
 118  *
 119  * regs_query_register_name() returns the name of a register from its
 120  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 121  */
 122 const char *regs_query_register_name(unsigned int offset)
 123 {
 124         const struct pt_regs_offset *roff;
 125         for (roff = regoffset_table; roff->name != NULL; roff++)
 126                 if (roff->offset == offset)
 127                         return roff->name;
 128         return NULL;
 129 }
 130
 131 /*
 132  * does not yet catch signals sent when the child dies.
 133  * in exit.c or in signal.c.
 134  */
 135
 136 /*
 137  * Determines which flags the user has access to [1 = access, 0 = no access].
 138  */
 139 #define FLAG_MASK_32            ((unsigned long)                        \
 140                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
 141                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
 142                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
 143                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
 144                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
 145
 146 /*
 147  * Determines whether a value may be installed in a segment register.
 148  */
 149 static inline bool invalid_selector(u16 value)
 150 {
 151         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
 152 }
 153
 154 #ifdef CONFIG_X86_32
 155
 156 #define FLAG_MASK               FLAG_MASK_32
 157
 158 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 159 {
 160         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 161         return &regs->bx + (regno >> 2);
 162 }
 163
 164 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 165 {
 166         /*
 167          * Returning the value truncates it to 16 bits.
 168          */
 169         unsigned int retval;
 170         if (offset != offsetof(struct user_regs_struct, gs))
 171                 retval = *pt_regs_access(task_pt_regs(task), offset);
 172         else {
 173                 if (task == current)
 174                         retval = get_user_gs(task_pt_regs(task));
 175                 else
 176                         retval = task_user_gs(task);
 177         }
 178         return retval;
 179 }
 180
 181 static int set_segment_reg(struct task_struct *task,
 182                            unsigned long offset, u16 value)
 183 {
 184         if (WARN_ON_ONCE(task == current))
 185                 return -EIO;
 186
 187         /*
 188          * The value argument was already truncated to 16 bits.
 189          */
 190         if (invalid_selector(value))
 191                 return -EIO;
 192
 193         /*
 194          * For %cs and %ss we cannot permit a null selector.
 195          * We can permit a bogus selector as long as it has USER_RPL.
 196          * Null selectors are fine for other segment registers, but
 197          * we will never get back to user mode with invalid %cs or %ss
 198          * and will take the trap in iret instead.  Much code relies
 199          * on user_mode() to distinguish a user trap frame (which can
 200          * safely use invalid selectors) from a kernel trap frame.
 201          */
 202         switch (offset) {
 203         case offsetof(struct user_regs_struct, cs):
 204         case offsetof(struct user_regs_struct, ss):
 205                 if (unlikely(value == 0))
 206                         return -EIO;
 207                 /* Else, fall through */
 208
 209         default:
 210                 *pt_regs_access(task_pt_regs(task), offset) = value;
 211                 break;
 212
 213         case offsetof(struct user_regs_struct, gs):
 214                 task_user_gs(task) = value;
 215         }
 216
 217         return 0;
 218 }
 219
 220 #else  /* CONFIG_X86_64 */
 221
 222 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
 223
 224 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 225 {
 226         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 227         return &regs->r15 + (offset / sizeof(regs->r15));
 228 }
 229
 230 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 231 {
 232         /*
 233          * Returning the value truncates it to 16 bits.
 234          */
 235         unsigned int seg;
 236
 237         switch (offset) {
 238         case offsetof(struct user_regs_struct, fs):
 239                 if (task == current) {
 240                         /* Older gas can't assemble movq %?s,%r?? */
 241                         asm("movl %%fs,%0" : "=r" (seg));
 242                         return seg;
 243                 }
 244                 return task->thread.fsindex;
 245         case offsetof(struct user_regs_struct, gs):
 246                 if (task == current) {
 247                         asm("movl %%gs,%0" : "=r" (seg));
 248                         return seg;
 249                 }
 250                 return task->thread.gsindex;
 251         case offsetof(struct user_regs_struct, ds):
 252                 if (task == current) {
 253                         asm("movl %%ds,%0" : "=r" (seg));
 254                         return seg;
 255                 }
 256                 return task->thread.ds;
 257         case offsetof(struct user_regs_struct, es):
 258                 if (task == current) {
 259                         asm("movl %%es,%0" : "=r" (seg));
 260                         return seg;
 261                 }
 262                 return task->thread.es;
 263
 264         case offsetof(struct user_regs_struct, cs):
 265         case offsetof(struct user_regs_struct, ss):
 266                 break;
 267         }
 268         return *pt_regs_access(task_pt_regs(task), offset);
 269 }
 270
 271 static int set_segment_reg(struct task_struct *task,
 272                            unsigned long offset, u16 value)
 273 {
 274         if (WARN_ON_ONCE(task == current))
 275                 return -EIO;
 276
 277         /*
 278          * The value argument was already truncated to 16 bits.
 279          */
 280         if (invalid_selector(value))
 281                 return -EIO;
 282
 283         /*
 284          * This function has some ABI oddities.
 285          *
 286          * A 32-bit ptracer probably expects that writing FS or GS will change
 287          * FSBASE or GSBASE respectively.  In the absence of FSGSBASE support,
 288          * this code indeed has that effect.  When FSGSBASE is added, this
 289          * will require a special case.
 290          *
 291          * For existing 64-bit ptracers, writing FS or GS *also* currently
 292          * changes the base if the selector is nonzero the next time the task
 293          * is run.  This behavior may not be needed, and trying to preserve it
 294          * when FSGSBASE is added would be complicated at best.
 295          */
 296
 297         switch (offset) {
 298         case offsetof(struct user_regs_struct,fs):
 299                 task->thread.fsindex = value;
 300                 break;
 301         case offsetof(struct user_regs_struct,gs):
 302                 task->thread.gsindex = value;
 303                 break;
 304         case offsetof(struct user_regs_struct,ds):
 305                 task->thread.ds = value;
 306                 break;
 307         case offsetof(struct user_regs_struct,es):
 308                 task->thread.es = value;
 309                 break;
 310
 311                 /*
 312                  * Can't actually change these in 64-bit mode.
 313                  */
 314         case offsetof(struct user_regs_struct,cs):
 315                 if (unlikely(value == 0))
 316                         return -EIO;
 317                 task_pt_regs(task)->cs = value;
 318                 break;
 319         case offsetof(struct user_regs_struct,ss):
 320                 if (unlikely(value == 0))
 321                         return -EIO;
 322                 task_pt_regs(task)->ss = value;
 323                 break;
 324         }
 325
 326         return 0;
 327 }
 328
 329 #endif  /* CONFIG_X86_32 */
 330
 331 static unsigned long get_flags(struct task_struct *task)
 332 {
 333         unsigned long retval = task_pt_regs(task)->flags;
 334
 335         /*
 336          * If the debugger set TF, hide it from the readout.
 337          */
 338         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 339                 retval &= ~X86_EFLAGS_TF;
 340
 341         return retval;
 342 }
 343
 344 static int set_flags(struct task_struct *task, unsigned long value)
 345 {
 346         struct pt_regs *regs = task_pt_regs(task);
 347
 348         /*
 349          * If the user value contains TF, mark that
 350          * it was not "us" (the debugger) that set it.
 351          * If not, make sure it stays set if we had.
 352          */
 353         if (value & X86_EFLAGS_TF)
 354                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
 355         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 356                 value |= X86_EFLAGS_TF;
 357
 358         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 359
 360         return 0;
 361 }
 362
 363 static int putreg(struct task_struct *child,
 364                   unsigned long offset, unsigned long value)
 365 {
 366         switch (offset) {
 367         case offsetof(struct user_regs_struct, cs):
 368         case offsetof(struct user_regs_struct, ds):
 369         case offsetof(struct user_regs_struct, es):
 370         case offsetof(struct user_regs_struct, fs):
 371         case offsetof(struct user_regs_struct, gs):
 372         case offsetof(struct user_regs_struct, ss):
 373                 return set_segment_reg(child, offset, value);
 374
 375         case offsetof(struct user_regs_struct, flags):
 376                 return set_flags(child, value);
 377
 378 #ifdef CONFIG_X86_64
 379         case offsetof(struct user_regs_struct,fs_base):
 380                 if (value >= TASK_SIZE_MAX)
 381                         return -EIO;
 382                 /*
 383                  * When changing the FS base, use do_arch_prctl_64()
 384                  * to set the index to zero and to set the base
 385                  * as requested.
 386                  *
 387                  * NB: This behavior is nonsensical and likely needs to
 388                  * change when FSGSBASE support is added.
 389                  */
 390                 if (child->thread.fsbase != value)
 391                         return do_arch_prctl_64(child, ARCH_SET_FS, value);
 392                 return 0;
 393         case offsetof(struct user_regs_struct,gs_base):
 394                 /*
 395                  * Exactly the same here as the %fs handling above.
 396                  */
 397                 if (value >= TASK_SIZE_MAX)
 398                         return -EIO;
 399                 if (child->thread.gsbase != value)
 400                         return do_arch_prctl_64(child, ARCH_SET_GS, value);
 401                 return 0;
 402 #endif
 403         }
 404
 405         *pt_regs_access(task_pt_regs(child), offset) = value;
 406         return 0;
 407 }
 408
 409 static unsigned long getreg(struct task_struct *task, unsigned long offset)
 410 {
 411         switch (offset) {
 412         case offsetof(struct user_regs_struct, cs):
 413         case offsetof(struct user_regs_struct, ds):
 414         case offsetof(struct user_regs_struct, es):
 415         case offsetof(struct user_regs_struct, fs):
 416         case offsetof(struct user_regs_struct, gs):
 417         case offsetof(struct user_regs_struct, ss):
 418                 return get_segment_reg(task, offset);
 419
 420         case offsetof(struct user_regs_struct, flags):
 421                 return get_flags(task);
 422
 423 #ifdef CONFIG_X86_64
 424         case offsetof(struct user_regs_struct, fs_base):
 425                 return x86_fsbase_read_task(task);
 426         case offsetof(struct user_regs_struct, gs_base):
 427                 return x86_gsbase_read_task(task);
 428 #endif
 429         }
 430
 431         return *pt_regs_access(task_pt_regs(task), offset);
 432 }
 433
 434 static int genregs_get(struct task_struct *target,
 435                        const struct user_regset *regset,
 436                        unsigned int pos, unsigned int count,
 437                        void *kbuf, void __user *ubuf)
 438 {
 439         if (kbuf) {
 440                 unsigned long *k = kbuf;
 441                 while (count >= sizeof(*k)) {
 442                         *k++ = getreg(target, pos);
 443                         count -= sizeof(*k);
 444                         pos += sizeof(*k);
 445                 }
 446         } else {
 447                 unsigned long __user *u = ubuf;
 448                 while (count >= sizeof(*u)) {
 449                         if (__put_user(getreg(target, pos), u++))
 450                                 return -EFAULT;
 451                         count -= sizeof(*u);
 452                         pos += sizeof(*u);
 453                 }
 454         }
 455
 456         return 0;
 457 }
 458
 459 static int genregs_set(struct task_struct *target,
 460                        const struct user_regset *regset,
 461                        unsigned int pos, unsigned int count,
 462                        const void *kbuf, const void __user *ubuf)
 463 {
 464         int ret = 0;
 465         if (kbuf) {
 466                 const unsigned long *k = kbuf;
 467                 while (count >= sizeof(*k) && !ret) {
 468                         ret = putreg(target, pos, *k++);
 469                         count -= sizeof(*k);
 470                         pos += sizeof(*k);
 471                 }
 472         } else {
 473                 const unsigned long  __user *u = ubuf;
 474                 while (count >= sizeof(*u) && !ret) {
 475                         unsigned long word;
 476                         ret = __get_user(word, u++);
 477                         if (ret)
 478                                 break;
 479                         ret = putreg(target, pos, word);
 480                         count -= sizeof(*u);
 481                         pos += sizeof(*u);
 482                 }
 483         }
 484         return ret;
 485 }
 486
 487 static void ptrace_triggered(struct perf_event *bp,
 488                              struct perf_sample_data *data,
 489                              struct pt_regs *regs)
 490 {
 491         int i;
 492         struct thread_struct *thread = &(current->thread);
 493
 494         /*
 495          * Store in the virtual DR6 register the fact that the breakpoint
 496          * was hit so the thread's debugger will see it.
 497          */
 498         for (i = 0; i < HBP_NUM; i++) {
 499                 if (thread->ptrace_bps[i] == bp)
 500                         break;
 501         }
 502
 503         thread->debugreg6 |= (DR_TRAP0 << i);
 504 }
 505
 506 /*
 507  * Walk through every ptrace breakpoints for this thread and
 508  * build the dr7 value on top of their attributes.
 509  *
 510  */
 511 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 512 {
 513         int i;
 514         int dr7 = 0;
 515         struct arch_hw_breakpoint *info;
 516
 517         for (i = 0; i < HBP_NUM; i++) {
 518                 if (bp[i] && !bp[i]->attr.disabled) {
 519                         info = counter_arch_bp(bp[i]);
 520                         dr7 |= encode_dr7(i, info->len, info->type);
 521                 }
 522         }
 523
 524         return dr7;
 525 }
 526
 527 static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
 528                                         int len, int type, bool disabled)
 529 {
 530         int err, bp_len, bp_type;
 531
 532         err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
 533         if (!err) {
 534                 attr->bp_len = bp_len;
 535                 attr->bp_type = bp_type;
 536                 attr->disabled = disabled;
 537         }
 538
 539         return err;
 540 }
 541
 542 static struct perf_event *
 543 ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
 544                                 unsigned long addr, bool disabled)
 545 {
 546         struct perf_event_attr attr;
 547         int err;
 548
 549         ptrace_breakpoint_init(&attr);
 550         attr.bp_addr = addr;
 551
 552         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 553         if (err)
 554                 return ERR_PTR(err);
 555
 556         return register_user_hw_breakpoint(&attr, ptrace_triggered,
 557                                                  NULL, tsk);
 558 }
 559
 560 static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 561                                         int disabled)
 562 {
 563         struct perf_event_attr attr = bp->attr;
 564         int err;
 565
 566         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 567         if (err)
 568                 return err;
 569
 570         return modify_user_hw_breakpoint(bp, &attr);
 571 }
 572
 573 /*
 574  * Handle ptrace writes to debug register 7.
 575  */
 576 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 577 {
 578         struct thread_struct *thread = &tsk->thread;
 579         unsigned long old_dr7;
 580         bool second_pass = false;
 581         int i, rc, ret = 0;
 582
 583         data &= ~DR_CONTROL_RESERVED;
 584         old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 585
 586 restore:
 587         rc = 0;
 588         for (i = 0; i < HBP_NUM; i++) {
 589                 unsigned len, type;
 590                 bool disabled = !decode_dr7(data, i, &len, &type);
 591                 struct perf_event *bp = thread->ptrace_bps[i];
 592
 593                 if (!bp) {
 594                         if (disabled)
 595                                 continue;
 596
 597                         bp = ptrace_register_breakpoint(tsk,
 598                                         len, type, 0, disabled);
 599                         if (IS_ERR(bp)) {
 600                                 rc = PTR_ERR(bp);
 601                                 break;
 602                         }
 603
 604                         thread->ptrace_bps[i] = bp;
 605                         continue;
 606                 }
 607
 608                 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
 609                 if (rc)
 610                         break;
 611         }
 612
 613         /* Restore if the first pass failed, second_pass shouldn't fail. */
 614         if (rc && !WARN_ON(second_pass)) {
 615                 ret = rc;
 616                 data = old_dr7;
 617                 second_pass = true;
 618                 goto restore;
 619         }
 620
 621         return ret;
 622 }
 623
 624 /*
 625  * Handle PTRACE_PEEKUSR calls for the debug register area.
 626  */
 627 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 628 {
 629         struct thread_struct *thread = &tsk->thread;
 630         unsigned long val = 0;
 631
 632         if (n < HBP_NUM) {
 633                 int index = array_index_nospec(n, HBP_NUM);
 634                 struct perf_event *bp = thread->ptrace_bps[index];
 635
 636                 if (bp)
 637                         val = bp->hw.info.address;
 638         } else if (n == 6) {
 639                 val = thread->debugreg6;
 640         } else if (n == 7) {
 641                 val = thread->ptrace_dr7;
 642         }
 643         return val;
 644 }
 645
 646 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 647                                       unsigned long addr)
 648 {
 649         struct thread_struct *t = &tsk->thread;
 650         struct perf_event *bp = t->ptrace_bps[nr];
 651         int err = 0;
 652
 653         if (!bp) {
 654                 /*
 655                  * Put stub len and type to create an inactive but correct bp.
 656                  *
 657                  * CHECKME: the previous code returned -EIO if the addr wasn't
 658                  * a valid task virtual addr. The new one will return -EINVAL in
 659                  *  this case.
 660                  * -EINVAL may be what we want for in-kernel breakpoints users,
 661                  * but -EIO looks better for ptrace, since we refuse a register
 662                  * writing for the user. And anyway this is the previous
 663                  * behaviour.
 664                  */
 665                 bp = ptrace_register_breakpoint(tsk,
 666                                 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
 667                                 addr, true);
 668                 if (IS_ERR(bp))
 669                         err = PTR_ERR(bp);
 670                 else
 671                         t->ptrace_bps[nr] = bp;
 672         } else {
 673                 struct perf_event_attr attr = bp->attr;
 674
 675                 attr.bp_addr = addr;
 676                 err = modify_user_hw_breakpoint(bp, &attr);
 677         }
 678
 679         return err;
 680 }
 681
 682 /*
 683  * Handle PTRACE_POKEUSR calls for the debug register area.
 684  */
 685 static int ptrace_set_debugreg(struct task_struct *tsk, int n,
 686                                unsigned long val)
 687 {
 688         struct thread_struct *thread = &tsk->thread;
 689         /* There are no DR4 or DR5 registers */
 690         int rc = -EIO;
 691
 692         if (n < HBP_NUM) {
 693                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
 694         } else if (n == 6) {
 695                 thread->debugreg6 = val;
 696                 rc = 0;
 697         } else if (n == 7) {
 698                 rc = ptrace_write_dr7(tsk, val);
 699                 if (!rc)
 700                         thread->ptrace_dr7 = val;
 701         }
 702         return rc;
 703 }
 704
 705 /*
 706  * These access the current or another (stopped) task's io permission
 707  * bitmap for debugging or core dump.
 708  */
 709 static int ioperm_active(struct task_struct *target,
 710                          const struct user_regset *regset)
 711 {
 712         struct io_bitmap *iobm = target->thread.io_bitmap;
 713
 714         return iobm ? DIV_ROUND_UP(iobm->max, regset->size) : 0;
 715 }
 716
 717 static int ioperm_get(struct task_struct *target,
 718                       const struct user_regset *regset,
 719                       unsigned int pos, unsigned int count,
 720                       void *kbuf, void __user *ubuf)
 721 {
 722         struct io_bitmap *iobm = target->thread.io_bitmap;
 723
 724         if (!iobm)
 725                 return -ENXIO;
 726
 727         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 728                                    iobm->bitmap, 0, IO_BITMAP_BYTES);
 729 }
 730
 731 /*
 732  * Called by kernel/ptrace.c when detaching..
 733  *
 734  * Make sure the single step bit is not set.
 735  */
 736 void ptrace_disable(struct task_struct *child)
 737 {
 738         user_disable_single_step(child);
 739 }
 740
 741 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 742 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 743 #endif
 744
 745 long arch_ptrace(struct task_struct *child, long request,
 746                  unsigned long addr, unsigned long data)
 747 {
 748         int ret;
 749         unsigned long __user *datap = (unsigned long __user *)data;
 750
 751         switch (request) {
 752         /* read the word at location addr in the USER area. */
 753         case PTRACE_PEEKUSR: {
 754                 unsigned long tmp;
 755
 756                 ret = -EIO;
 757                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 758                         break;
 759
 760                 tmp = 0;  /* Default return condition */
 761                 if (addr < sizeof(struct user_regs_struct))
 762                         tmp = getreg(child, addr);
 763                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 764                          addr <= offsetof(struct user, u_debugreg[7])) {
 765                         addr -= offsetof(struct user, u_debugreg[0]);
 766                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 767                 }
 768                 ret = put_user(tmp, datap);
 769                 break;
 770         }
 771
 772         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 773                 ret = -EIO;
 774                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 775                         break;
 776
 777                 if (addr < sizeof(struct user_regs_struct))
 778                         ret = putreg(child, addr, data);
 779                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 780                          addr <= offsetof(struct user, u_debugreg[7])) {
 781                         addr -= offsetof(struct user, u_debugreg[0]);
 782                         ret = ptrace_set_debugreg(child,
 783                                                   addr / sizeof(data), data);
 784                 }
 785                 break;
 786
 787         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 788                 return copy_regset_to_user(child,
 789                                            task_user_regset_view(current),
 790                                            REGSET_GENERAL,
 791                                            0, sizeof(struct user_regs_struct),
 792                                            datap);
 793
 794         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 795                 return copy_regset_from_user(child,
 796                                              task_user_regset_view(current),
 797                                              REGSET_GENERAL,
 798                                              0, sizeof(struct user_regs_struct),
 799                                              datap);
 800
 801         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 802                 return copy_regset_to_user(child,
 803                                            task_user_regset_view(current),
 804                                            REGSET_FP,
 805                                            0, sizeof(struct user_i387_struct),
 806                                            datap);
 807
 808         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 809                 return copy_regset_from_user(child,
 810                                              task_user_regset_view(current),
 811                                              REGSET_FP,
 812                                              0, sizeof(struct user_i387_struct),
 813                                              datap);
 814
 815 #ifdef CONFIG_X86_32
 816         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
 817                 return copy_regset_to_user(child, &user_x86_32_view,
 818                                            REGSET_XFP,
 819                                            0, sizeof(struct user_fxsr_struct),
 820                                            datap) ? -EIO : 0;
 821
 822         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
 823                 return copy_regset_from_user(child, &user_x86_32_view,
 824                                              REGSET_XFP,
 825                                              0, sizeof(struct user_fxsr_struct),
 826                                              datap) ? -EIO : 0;
 827 #endif
 828
 829 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 830         case PTRACE_GET_THREAD_AREA:
 831                 if ((int) addr < 0)
 832                         return -EIO;
 833                 ret = do_get_thread_area(child, addr,
 834                                         (struct user_desc __user *)data);
 835                 break;
 836
 837         case PTRACE_SET_THREAD_AREA:
 838                 if ((int) addr < 0)
 839                         return -EIO;
 840                 ret = do_set_thread_area(child, addr,
 841                                         (struct user_desc __user *)data, 0);
 842                 break;
 843 #endif
 844
 845 #ifdef CONFIG_X86_64
 846                 /* normal 64bit interface to access TLS data.
 847                    Works just like arch_prctl, except that the arguments
 848                    are reversed. */
 849         case PTRACE_ARCH_PRCTL:
 850                 ret = do_arch_prctl_64(child, data, addr);
 851                 break;
 852 #endif
 853
 854         default:
 855                 ret = ptrace_request(child, request, addr, data);
 856                 break;
 857         }
 858
 859         return ret;
 860 }
 861
 862 #ifdef CONFIG_IA32_EMULATION
 863
 864 #include <linux/compat.h>
 865 #include <linux/syscalls.h>
 866 #include <asm/ia32.h>
 867 #include <asm/user32.h>
 868
 869 #define R32(l,q)                                                        \
 870         case offsetof(struct user32, regs.l):                           \
 871                 regs->q = value; break
 872
 873 #define SEG32(rs)                                                       \
 874         case offsetof(struct user32, regs.rs):                          \
 875                 return set_segment_reg(child,                           \
 876                                        offsetof(struct user_regs_struct, rs), \
 877                                        value);                          \
 878                 break
 879
 880 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 881 {
 882         struct pt_regs *regs = task_pt_regs(child);
 883
 884         switch (regno) {
 885
 886         SEG32(cs);
 887         SEG32(ds);
 888         SEG32(es);
 889         SEG32(fs);
 890         SEG32(gs);
 891         SEG32(ss);
 892
 893         R32(ebx, bx);
 894         R32(ecx, cx);
 895         R32(edx, dx);
 896         R32(edi, di);
 897         R32(esi, si);
 898         R32(ebp, bp);
 899         R32(eax, ax);
 900         R32(eip, ip);
 901         R32(esp, sp);
 902
 903         case offsetof(struct user32, regs.orig_eax):
 904                 /*
 905                  * Warning: bizarre corner case fixup here.  A 32-bit
 906                  * debugger setting orig_eax to -1 wants to disable
 907                  * syscall restart.  Make sure that the syscall
 908                  * restart code sign-extends orig_ax.  Also make sure
 909                  * we interpret the -ERESTART* codes correctly if
 910                  * loaded into regs->ax in case the task is not
 911                  * actually still sitting at the exit from a 32-bit
 912                  * syscall with TS_COMPAT still set.
 913                  */
 914                 regs->orig_ax = value;
 915                 if (syscall_get_nr(child, regs) >= 0)
 916                         child->thread_info.status |= TS_I386_REGS_POKED;
 917                 break;
 918
 919         case offsetof(struct user32, regs.eflags):
 920                 return set_flags(child, value);
 921
 922         case offsetof(struct user32, u_debugreg[0]) ...
 923                 offsetof(struct user32, u_debugreg[7]):
 924                 regno -= offsetof(struct user32, u_debugreg[0]);
 925                 return ptrace_set_debugreg(child, regno / 4, value);
 926
 927         default:
 928                 if (regno > sizeof(struct user32) || (regno & 3))
 929                         return -EIO;
 930
 931                 /*
 932                  * Other dummy fields in the virtual user structure
 933                  * are ignored
 934                  */
 935                 break;
 936         }
 937         return 0;
 938 }
 939
 940 #undef R32
 941 #undef SEG32
 942
 943 #define R32(l,q)                                                        \
 944         case offsetof(struct user32, regs.l):                           \
 945                 *val = regs->q; break
 946
 947 #define SEG32(rs)                                                       \
 948         case offsetof(struct user32, regs.rs):                          \
 949                 *val = get_segment_reg(child,                           \
 950                                        offsetof(struct user_regs_struct, rs)); \
 951                 break
 952
 953 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 954 {
 955         struct pt_regs *regs = task_pt_regs(child);
 956
 957         switch (regno) {
 958
 959         SEG32(ds);
 960         SEG32(es);
 961         SEG32(fs);
 962         SEG32(gs);
 963
 964         R32(cs, cs);
 965         R32(ss, ss);
 966         R32(ebx, bx);
 967         R32(ecx, cx);
 968         R32(edx, dx);
 969         R32(edi, di);
 970         R32(esi, si);
 971         R32(ebp, bp);
 972         R32(eax, ax);
 973         R32(orig_eax, orig_ax);
 974         R32(eip, ip);
 975         R32(esp, sp);
 976
 977         case offsetof(struct user32, regs.eflags):
 978                 *val = get_flags(child);
 979                 break;
 980
 981         case offsetof(struct user32, u_debugreg[0]) ...
 982                 offsetof(struct user32, u_debugreg[7]):
 983                 regno -= offsetof(struct user32, u_debugreg[0]);
 984                 *val = ptrace_get_debugreg(child, regno / 4);
 985                 break;
 986
 987         default:
 988                 if (regno > sizeof(struct user32) || (regno & 3))
 989                         return -EIO;
 990
 991                 /*
 992                  * Other dummy fields in the virtual user structure
 993                  * are ignored
 994                  */
 995                 *val = 0;
 996                 break;
 997         }
 998         return 0;
 999 }
1000
1001 #undef R32
1002 #undef SEG32
1003
1004 static int genregs32_get(struct task_struct *target,
1005                          const struct user_regset *regset,
1006                          unsigned int pos, unsigned int count,
1007                          void *kbuf, void __user *ubuf)
1008 {
1009         if (kbuf) {
1010                 compat_ulong_t *k = kbuf;
1011                 while (count >= sizeof(*k)) {
1012                         getreg32(target, pos, k++);
1013                         count -= sizeof(*k);
1014                         pos += sizeof(*k);
1015                 }
1016         } else {
1017                 compat_ulong_t __user *u = ubuf;
1018                 while (count >= sizeof(*u)) {
1019                         compat_ulong_t word;
1020                         getreg32(target, pos, &word);
1021                         if (__put_user(word, u++))
1022                                 return -EFAULT;
1023                         count -= sizeof(*u);
1024                         pos += sizeof(*u);
1025                 }
1026         }
1027
1028         return 0;
1029 }
1030
1031 static int genregs32_set(struct task_struct *target,
1032                          const struct user_regset *regset,
1033                          unsigned int pos, unsigned int count,
1034                          const void *kbuf, const void __user *ubuf)
1035 {
1036         int ret = 0;
1037         if (kbuf) {
1038                 const compat_ulong_t *k = kbuf;
1039                 while (count >= sizeof(*k) && !ret) {
1040                         ret = putreg32(target, pos, *k++);
1041                         count -= sizeof(*k);
1042                         pos += sizeof(*k);
1043                 }
1044         } else {
1045                 const compat_ulong_t __user *u = ubuf;
1046                 while (count >= sizeof(*u) && !ret) {
1047                         compat_ulong_t word;
1048                         ret = __get_user(word, u++);
1049                         if (ret)
1050                                 break;
1051                         ret = putreg32(target, pos, word);
1052                         count -= sizeof(*u);
1053                         pos += sizeof(*u);
1054                 }
1055         }
1056         return ret;
1057 }
1058
1059 static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1060                              compat_ulong_t caddr, compat_ulong_t cdata)
1061 {
1062         unsigned long addr = caddr;
1063         unsigned long data = cdata;
1064         void __user *datap = compat_ptr(data);
1065         int ret;
1066         __u32 val;
1067
1068         switch (request) {
1069         case PTRACE_PEEKUSR:
1070                 ret = getreg32(child, addr, &val);
1071                 if (ret == 0)
1072                         ret = put_user(val, (__u32 __user *)datap);
1073                 break;
1074
1075         case PTRACE_POKEUSR:
1076                 ret = putreg32(child, addr, data);
1077                 break;
1078
1079         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1080                 return copy_regset_to_user(child, &user_x86_32_view,
1081                                            REGSET_GENERAL,
1082                                            0, sizeof(struct user_regs_struct32),
1083                                            datap);
1084
1085         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1086                 return copy_regset_from_user(child, &user_x86_32_view,
1087                                              REGSET_GENERAL, 0,
1088                                              sizeof(struct user_regs_struct32),
1089                                              datap);
1090
1091         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1092                 return copy_regset_to_user(child, &user_x86_32_view,
1093                                            REGSET_FP, 0,
1094                                            sizeof(struct user_i387_ia32_struct),
1095                                            datap);
1096
1097         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1098                 return copy_regset_from_user(
1099                         child, &user_x86_32_view, REGSET_FP,
1100                         0, sizeof(struct user_i387_ia32_struct), datap);
1101
1102         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1103                 return copy_regset_to_user(child, &user_x86_32_view,
1104                                            REGSET_XFP, 0,
1105                                            sizeof(struct user32_fxsr_struct),
1106                                            datap);
1107
1108         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1109                 return copy_regset_from_user(child, &user_x86_32_view,
1110                                              REGSET_XFP, 0,
1111                                              sizeof(struct user32_fxsr_struct),
1112                                              datap);
1113
1114         case PTRACE_GET_THREAD_AREA:
1115         case PTRACE_SET_THREAD_AREA:
1116                 return arch_ptrace(child, request, addr, data);
1117
1118         default:
1119                 return compat_ptrace_request(child, request, addr, data);
1120         }
1121
1122         return ret;
1123 }
1124 #endif /* CONFIG_IA32_EMULATION */
1125
1126 #ifdef CONFIG_X86_X32_ABI
1127 static long x32_arch_ptrace(struct task_struct *child,
1128                             compat_long_t request, compat_ulong_t caddr,
1129                             compat_ulong_t cdata)
1130 {
1131         unsigned long addr = caddr;
1132         unsigned long data = cdata;
1133         void __user *datap = compat_ptr(data);
1134         int ret;
1135
1136         switch (request) {
1137         /* Read 32bits at location addr in the USER area.  Only allow
1138            to return the lower 32bits of segment and debug registers.  */
1139         case PTRACE_PEEKUSR: {
1140                 u32 tmp;
1141
1142                 ret = -EIO;
1143                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1144                     addr < offsetof(struct user_regs_struct, cs))
1145                         break;
1146
1147                 tmp = 0;  /* Default return condition */
1148                 if (addr < sizeof(struct user_regs_struct))
1149                         tmp = getreg(child, addr);
1150                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1151                          addr <= offsetof(struct user, u_debugreg[7])) {
1152                         addr -= offsetof(struct user, u_debugreg[0]);
1153                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1154                 }
1155                 ret = put_user(tmp, (__u32 __user *)datap);
1156                 break;
1157         }
1158
1159         /* Write the word at location addr in the USER area.  Only allow
1160            to update segment and debug registers with the upper 32bits
1161            zero-extended. */
1162         case PTRACE_POKEUSR:
1163                 ret = -EIO;
1164                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1165                     addr < offsetof(struct user_regs_struct, cs))
1166                         break;
1167
1168                 if (addr < sizeof(struct user_regs_struct))
1169                         ret = putreg(child, addr, data);
1170                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1171                          addr <= offsetof(struct user, u_debugreg[7])) {
1172                         addr -= offsetof(struct user, u_debugreg[0]);
1173                         ret = ptrace_set_debugreg(child,
1174                                                   addr / sizeof(data), data);
1175                 }
1176                 break;
1177
1178         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1179                 return copy_regset_to_user(child,
1180                                            task_user_regset_view(current),
1181                                            REGSET_GENERAL,
1182                                            0, sizeof(struct user_regs_struct),
1183                                            datap);
1184
1185         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1186                 return copy_regset_from_user(child,
1187                                              task_user_regset_view(current),
1188                                              REGSET_GENERAL,
1189                                              0, sizeof(struct user_regs_struct),
1190                                              datap);
1191
1192         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1193                 return copy_regset_to_user(child,
1194                                            task_user_regset_view(current),
1195                                            REGSET_FP,
1196                                            0, sizeof(struct user_i387_struct),
1197                                            datap);
1198
1199         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1200                 return copy_regset_from_user(child,
1201                                              task_user_regset_view(current),
1202                                              REGSET_FP,
1203                                              0, sizeof(struct user_i387_struct),
1204                                              datap);
1205
1206         default:
1207                 return compat_ptrace_request(child, request, addr, data);
1208         }
1209
1210         return ret;
1211 }
1212 #endif
1213
1214 #ifdef CONFIG_COMPAT
1215 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1216                         compat_ulong_t caddr, compat_ulong_t cdata)
1217 {
1218 #ifdef CONFIG_X86_X32_ABI
1219         if (!in_ia32_syscall())
1220                 return x32_arch_ptrace(child, request, caddr, cdata);
1221 #endif
1222 #ifdef CONFIG_IA32_EMULATION
1223         return ia32_arch_ptrace(child, request, caddr, cdata);
1224 #else
1225         return 0;
1226 #endif
1227 }
1228 #endif  /* CONFIG_COMPAT */
1229
1230 #ifdef CONFIG_X86_64
1231
1232 static struct user_regset x86_64_regsets[] __ro_after_init = {
1233         [REGSET_GENERAL] = {
1234                 .core_note_type = NT_PRSTATUS,
1235                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1236                 .size = sizeof(long), .align = sizeof(long),
1237                 .get = genregs_get, .set = genregs_set
1238         },
1239         [REGSET_FP] = {
1240                 .core_note_type = NT_PRFPREG,
1241                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1242                 .size = sizeof(long), .align = sizeof(long),
1243                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1244         },
1245         [REGSET_XSTATE] = {
1246                 .core_note_type = NT_X86_XSTATE,
1247                 .size = sizeof(u64), .align = sizeof(u64),
1248                 .active = xstateregs_active, .get = xstateregs_get,
1249                 .set = xstateregs_set
1250         },
1251         [REGSET_IOPERM64] = {
1252                 .core_note_type = NT_386_IOPERM,
1253                 .n = IO_BITMAP_LONGS,
1254                 .size = sizeof(long), .align = sizeof(long),
1255                 .active = ioperm_active, .get = ioperm_get
1256         },
1257 };
1258
1259 static const struct user_regset_view user_x86_64_view = {
1260         .name = "x86_64", .e_machine = EM_X86_64,
1261         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1262 };
1263
1264 #else  /* CONFIG_X86_32 */
1265
1266 #define user_regs_struct32      user_regs_struct
1267 #define genregs32_get           genregs_get
1268 #define genregs32_set           genregs_set
1269
1270 #endif  /* CONFIG_X86_64 */
1271
1272 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1273 static struct user_regset x86_32_regsets[] __ro_after_init = {
1274         [REGSET_GENERAL] = {
1275                 .core_note_type = NT_PRSTATUS,
1276                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1277                 .size = sizeof(u32), .align = sizeof(u32),
1278                 .get = genregs32_get, .set = genregs32_set
1279         },
1280         [REGSET_FP] = {
1281                 .core_note_type = NT_PRFPREG,
1282                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1283                 .size = sizeof(u32), .align = sizeof(u32),
1284                 .active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1285         },
1286         [REGSET_XFP] = {
1287                 .core_note_type = NT_PRXFPREG,
1288                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1289                 .size = sizeof(u32), .align = sizeof(u32),
1290                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1291         },
1292         [REGSET_XSTATE] = {
1293                 .core_note_type = NT_X86_XSTATE,
1294                 .size = sizeof(u64), .align = sizeof(u64),
1295                 .active = xstateregs_active, .get = xstateregs_get,
1296                 .set = xstateregs_set
1297         },
1298         [REGSET_TLS] = {
1299                 .core_note_type = NT_386_TLS,
1300                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1301                 .size = sizeof(struct user_desc),
1302                 .align = sizeof(struct user_desc),
1303                 .active = regset_tls_active,
1304                 .get = regset_tls_get, .set = regset_tls_set
1305         },
1306         [REGSET_IOPERM32] = {
1307                 .core_note_type = NT_386_IOPERM,
1308                 .n = IO_BITMAP_BYTES / sizeof(u32),
1309                 .size = sizeof(u32), .align = sizeof(u32),
1310                 .active = ioperm_active, .get = ioperm_get
1311         },
1312 };
1313
1314 static const struct user_regset_view user_x86_32_view = {
1315         .name = "i386", .e_machine = EM_386,
1316         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1317 };
1318 #endif
1319
1320 /*
1321  * This represents bytes 464..511 in the memory layout exported through
1322  * the REGSET_XSTATE interface.
1323  */
1324 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1325
1326 void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1327 {
1328 #ifdef CONFIG_X86_64
1329         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1330 #endif
1331 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1332         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1333 #endif
1334         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1335 }
1336
1337 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1338 {
1339 #ifdef CONFIG_IA32_EMULATION
1340         if (!user_64bit_mode(task_pt_regs(task)))
1341 #endif
1342 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1343                 return &user_x86_32_view;
1344 #endif
1345 #ifdef CONFIG_X86_64
1346         return &user_x86_64_view;
1347 #endif
1348 }
1349
1350 void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
1351 {
1352         struct task_struct *tsk = current;
1353
1354         tsk->thread.trap_nr = X86_TRAP_DB;
1355         tsk->thread.error_code = error_code;
1356
1357         /* Send us the fake SIGTRAP */
1358         force_sig_fault(SIGTRAP, si_code,
1359                         user_mode(regs) ? (void __user *)regs->ip : NULL);
1360 }
1361
1362 void user_single_step_report(struct pt_regs *regs)
1363 {
1364         send_sigtrap(regs, 0, TRAP_BRKPT);
1365 }