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/pgtable.h>
  32 #include <asm/processor.h>
  33 #include <asm/fpu/internal.h>
  34 #include <asm/fpu/signal.h>
  35 #include <asm/fpu/regset.h>
  36 #include <asm/debugreg.h>
  37 #include <asm/ldt.h>
  38 #include <asm/desc.h>
  39 #include <asm/prctl.h>
  40 #include <asm/proto.h>
  41 #include <asm/hw_breakpoint.h>
  42 #include <asm/traps.h>
  43 #include <asm/syscall.h>
  44 #include <asm/fsgsbase.h>
  45 #include <asm/io_bitmap.h>
  46
  47 #include "tls.h"
  48
  49 enum x86_regset {
  50         REGSET_GENERAL,
  51         REGSET_FP,
  52         REGSET_XFP,
  53         REGSET_IOPERM64 = REGSET_XFP,
  54         REGSET_XSTATE,
  55         REGSET_TLS,
  56         REGSET_IOPERM32,
  57 };
  58
  59 struct pt_regs_offset {
  60         const char *name;
  61         int offset;
  62 };
  63
  64 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  65 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  66
  67 static const struct pt_regs_offset regoffset_table[] = {
  68 #ifdef CONFIG_X86_64
  69         REG_OFFSET_NAME(r15),
  70         REG_OFFSET_NAME(r14),
  71         REG_OFFSET_NAME(r13),
  72         REG_OFFSET_NAME(r12),
  73         REG_OFFSET_NAME(r11),
  74         REG_OFFSET_NAME(r10),
  75         REG_OFFSET_NAME(r9),
  76         REG_OFFSET_NAME(r8),
  77 #endif
  78         REG_OFFSET_NAME(bx),
  79         REG_OFFSET_NAME(cx),
  80         REG_OFFSET_NAME(dx),
  81         REG_OFFSET_NAME(si),
  82         REG_OFFSET_NAME(di),
  83         REG_OFFSET_NAME(bp),
  84         REG_OFFSET_NAME(ax),
  85 #ifdef CONFIG_X86_32
  86         REG_OFFSET_NAME(ds),
  87         REG_OFFSET_NAME(es),
  88         REG_OFFSET_NAME(fs),
  89         REG_OFFSET_NAME(gs),
  90 #endif
  91         REG_OFFSET_NAME(orig_ax),
  92         REG_OFFSET_NAME(ip),
  93         REG_OFFSET_NAME(cs),
  94         REG_OFFSET_NAME(flags),
  95         REG_OFFSET_NAME(sp),
  96         REG_OFFSET_NAME(ss),
  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         for (roff = regoffset_table; roff->name != NULL; roff++)
 111                 if (!strcmp(roff->name, name))
 112                         return roff->offset;
 113         return -EINVAL;
 114 }
 115
 116 /**
 117  * regs_query_register_name() - query register name from its offset
 118  * @offset:     the offset of a register in struct pt_regs.
 119  *
 120  * regs_query_register_name() returns the name of a register from its
 121  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 122  */
 123 const char *regs_query_register_name(unsigned int offset)
 124 {
 125         const struct pt_regs_offset *roff;
 126         for (roff = regoffset_table; roff->name != NULL; roff++)
 127                 if (roff->offset == offset)
 128                         return roff->name;
 129         return NULL;
 130 }
 131
 132 /*
 133  * does not yet catch signals sent when the child dies.
 134  * in exit.c or in signal.c.
 135  */
 136
 137 /*
 138  * Determines which flags the user has access to [1 = access, 0 = no access].
 139  */
 140 #define FLAG_MASK_32            ((unsigned long)                        \
 141                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
 142                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
 143                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
 144                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
 145                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
 146
 147 /*
 148  * Determines whether a value may be installed in a segment register.
 149  */
 150 static inline bool invalid_selector(u16 value)
 151 {
 152         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
 153 }
 154
 155 #ifdef CONFIG_X86_32
 156
 157 #define FLAG_MASK               FLAG_MASK_32
 158
 159 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 160 {
 161         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 162         return &regs->bx + (regno >> 2);
 163 }
 164
 165 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 166 {
 167         /*
 168          * Returning the value truncates it to 16 bits.
 169          */
 170         unsigned int retval;
 171         if (offset != offsetof(struct user_regs_struct, gs))
 172                 retval = *pt_regs_access(task_pt_regs(task), offset);
 173         else {
 174                 if (task == current)
 175                         retval = get_user_gs(task_pt_regs(task));
 176                 else
 177                         retval = task_user_gs(task);
 178         }
 179         return retval;
 180 }
 181
 182 static int set_segment_reg(struct task_struct *task,
 183                            unsigned long offset, u16 value)
 184 {
 185         if (WARN_ON_ONCE(task == current))
 186                 return -EIO;
 187
 188         /*
 189          * The value argument was already truncated to 16 bits.
 190          */
 191         if (invalid_selector(value))
 192                 return -EIO;
 193
 194         /*
 195          * For %cs and %ss we cannot permit a null selector.
 196          * We can permit a bogus selector as long as it has USER_RPL.
 197          * Null selectors are fine for other segment registers, but
 198          * we will never get back to user mode with invalid %cs or %ss
 199          * and will take the trap in iret instead.  Much code relies
 200          * on user_mode() to distinguish a user trap frame (which can
 201          * safely use invalid selectors) from a kernel trap frame.
 202          */
 203         switch (offset) {
 204         case offsetof(struct user_regs_struct, cs):
 205         case offsetof(struct user_regs_struct, ss):
 206                 if (unlikely(value == 0))
 207                         return -EIO;
 208                 /* Else, fall through */
 209
 210         default:
 211                 *pt_regs_access(task_pt_regs(task), offset) = value;
 212                 break;
 213
 214         case offsetof(struct user_regs_struct, gs):
 215                 task_user_gs(task) = value;
 216         }
 217
 218         return 0;
 219 }
 220
 221 #else  /* CONFIG_X86_64 */
 222
 223 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
 224
 225 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 226 {
 227         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 228         return &regs->r15 + (offset / sizeof(regs->r15));
 229 }
 230
 231 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 232 {
 233         /*
 234          * Returning the value truncates it to 16 bits.
 235          */
 236         unsigned int seg;
 237
 238         switch (offset) {
 239         case offsetof(struct user_regs_struct, fs):
 240                 if (task == current) {
 241                         /* Older gas can't assemble movq %?s,%r?? */
 242                         asm("movl %%fs,%0" : "=r" (seg));
 243                         return seg;
 244                 }
 245                 return task->thread.fsindex;
 246         case offsetof(struct user_regs_struct, gs):
 247                 if (task == current) {
 248                         asm("movl %%gs,%0" : "=r" (seg));
 249                         return seg;
 250                 }
 251                 return task->thread.gsindex;
 252         case offsetof(struct user_regs_struct, ds):
 253                 if (task == current) {
 254                         asm("movl %%ds,%0" : "=r" (seg));
 255                         return seg;
 256                 }
 257                 return task->thread.ds;
 258         case offsetof(struct user_regs_struct, es):
 259                 if (task == current) {
 260                         asm("movl %%es,%0" : "=r" (seg));
 261                         return seg;
 262                 }
 263                 return task->thread.es;
 264
 265         case offsetof(struct user_regs_struct, cs):
 266         case offsetof(struct user_regs_struct, ss):
 267                 break;
 268         }
 269         return *pt_regs_access(task_pt_regs(task), offset);
 270 }
 271
 272 static int set_segment_reg(struct task_struct *task,
 273                            unsigned long offset, u16 value)
 274 {
 275         if (WARN_ON_ONCE(task == current))
 276                 return -EIO;
 277
 278         /*
 279          * The value argument was already truncated to 16 bits.
 280          */
 281         if (invalid_selector(value))
 282                 return -EIO;
 283
 284         /*
 285          * This function has some ABI oddities.
 286          *
 287          * A 32-bit ptracer probably expects that writing FS or GS will change
 288          * FSBASE or GSBASE respectively.  In the absence of FSGSBASE support,
 289          * this code indeed has that effect.  When FSGSBASE is added, this
 290          * will require a special case.
 291          *
 292          * For existing 64-bit ptracers, writing FS or GS *also* currently
 293          * changes the base if the selector is nonzero the next time the task
 294          * is run.  This behavior may not be needed, and trying to preserve it
 295          * when FSGSBASE is added would be complicated at best.
 296          */
 297
 298         switch (offset) {
 299         case offsetof(struct user_regs_struct,fs):
 300                 task->thread.fsindex = value;
 301                 break;
 302         case offsetof(struct user_regs_struct,gs):
 303                 task->thread.gsindex = value;
 304                 break;
 305         case offsetof(struct user_regs_struct,ds):
 306                 task->thread.ds = value;
 307                 break;
 308         case offsetof(struct user_regs_struct,es):
 309                 task->thread.es = value;
 310                 break;
 311
 312                 /*
 313                  * Can't actually change these in 64-bit mode.
 314                  */
 315         case offsetof(struct user_regs_struct,cs):
 316                 if (unlikely(value == 0))
 317                         return -EIO;
 318                 task_pt_regs(task)->cs = value;
 319                 break;
 320         case offsetof(struct user_regs_struct,ss):
 321                 if (unlikely(value == 0))
 322                         return -EIO;
 323                 task_pt_regs(task)->ss = value;
 324                 break;
 325         }
 326
 327         return 0;
 328 }
 329
 330 #endif  /* CONFIG_X86_32 */
 331
 332 static unsigned long get_flags(struct task_struct *task)
 333 {
 334         unsigned long retval = task_pt_regs(task)->flags;
 335
 336         /*
 337          * If the debugger set TF, hide it from the readout.
 338          */
 339         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 340                 retval &= ~X86_EFLAGS_TF;
 341
 342         return retval;
 343 }
 344
 345 static int set_flags(struct task_struct *task, unsigned long value)
 346 {
 347         struct pt_regs *regs = task_pt_regs(task);
 348
 349         /*
 350          * If the user value contains TF, mark that
 351          * it was not "us" (the debugger) that set it.
 352          * If not, make sure it stays set if we had.
 353          */
 354         if (value & X86_EFLAGS_TF)
 355                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
 356         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 357                 value |= X86_EFLAGS_TF;
 358
 359         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 360
 361         return 0;
 362 }
 363
 364 static int putreg(struct task_struct *child,
 365                   unsigned long offset, unsigned long value)
 366 {
 367         switch (offset) {
 368         case offsetof(struct user_regs_struct, cs):
 369         case offsetof(struct user_regs_struct, ds):
 370         case offsetof(struct user_regs_struct, es):
 371         case offsetof(struct user_regs_struct, fs):
 372         case offsetof(struct user_regs_struct, gs):
 373         case offsetof(struct user_regs_struct, ss):
 374                 return set_segment_reg(child, offset, value);
 375
 376         case offsetof(struct user_regs_struct, flags):
 377                 return set_flags(child, value);
 378
 379 #ifdef CONFIG_X86_64
 380         case offsetof(struct user_regs_struct,fs_base):
 381                 if (value >= TASK_SIZE_MAX)
 382                         return -EIO;
 383                 /*
 384                  * When changing the FS base, use do_arch_prctl_64()
 385                  * to set the index to zero and to set the base
 386                  * as requested.
 387                  *
 388                  * NB: This behavior is nonsensical and likely needs to
 389                  * change when FSGSBASE support is added.
 390                  */
 391                 if (child->thread.fsbase != value)
 392                         return do_arch_prctl_64(child, ARCH_SET_FS, value);
 393                 return 0;
 394         case offsetof(struct user_regs_struct,gs_base):
 395                 /*
 396                  * Exactly the same here as the %fs handling above.
 397                  */
 398                 if (value >= TASK_SIZE_MAX)
 399                         return -EIO;
 400                 if (child->thread.gsbase != value)
 401                         return do_arch_prctl_64(child, ARCH_SET_GS, value);
 402                 return 0;
 403 #endif
 404         }
 405
 406         *pt_regs_access(task_pt_regs(child), offset) = value;
 407         return 0;
 408 }
 409
 410 static unsigned long getreg(struct task_struct *task, unsigned long offset)
 411 {
 412         switch (offset) {
 413         case offsetof(struct user_regs_struct, cs):
 414         case offsetof(struct user_regs_struct, ds):
 415         case offsetof(struct user_regs_struct, es):
 416         case offsetof(struct user_regs_struct, fs):
 417         case offsetof(struct user_regs_struct, gs):
 418         case offsetof(struct user_regs_struct, ss):
 419                 return get_segment_reg(task, offset);
 420
 421         case offsetof(struct user_regs_struct, flags):
 422                 return get_flags(task);
 423
 424 #ifdef CONFIG_X86_64
 425         case offsetof(struct user_regs_struct, fs_base):
 426                 return x86_fsbase_read_task(task);
 427         case offsetof(struct user_regs_struct, gs_base):
 428                 return x86_gsbase_read_task(task);
 429 #endif
 430         }
 431
 432         return *pt_regs_access(task_pt_regs(task), offset);
 433 }
 434
 435 static int genregs_get(struct task_struct *target,
 436                        const struct user_regset *regset,
 437                        unsigned int pos, unsigned int count,
 438                        void *kbuf, void __user *ubuf)
 439 {
 440         if (kbuf) {
 441                 unsigned long *k = kbuf;
 442                 while (count >= sizeof(*k)) {
 443                         *k++ = getreg(target, pos);
 444                         count -= sizeof(*k);
 445                         pos += sizeof(*k);
 446                 }
 447         } else {
 448                 unsigned long __user *u = ubuf;
 449                 while (count >= sizeof(*u)) {
 450                         if (__put_user(getreg(target, pos), u++))
 451                                 return -EFAULT;
 452                         count -= sizeof(*u);
 453                         pos += sizeof(*u);
 454                 }
 455         }
 456
 457         return 0;
 458 }
 459
 460 static int genregs_set(struct task_struct *target,
 461                        const struct user_regset *regset,
 462                        unsigned int pos, unsigned int count,
 463                        const void *kbuf, const void __user *ubuf)
 464 {
 465         int ret = 0;
 466         if (kbuf) {
 467                 const unsigned long *k = kbuf;
 468                 while (count >= sizeof(*k) && !ret) {
 469                         ret = putreg(target, pos, *k++);
 470                         count -= sizeof(*k);
 471                         pos += sizeof(*k);
 472                 }
 473         } else {
 474                 const unsigned long  __user *u = ubuf;
 475                 while (count >= sizeof(*u) && !ret) {
 476                         unsigned long word;
 477                         ret = __get_user(word, u++);
 478                         if (ret)
 479                                 break;
 480                         ret = putreg(target, pos, word);
 481                         count -= sizeof(*u);
 482                         pos += sizeof(*u);
 483                 }
 484         }
 485         return ret;
 486 }
 487
 488 static void ptrace_triggered(struct perf_event *bp,
 489                              struct perf_sample_data *data,
 490                              struct pt_regs *regs)
 491 {
 492         int i;
 493         struct thread_struct *thread = &(current->thread);
 494
 495         /*
 496          * Store in the virtual DR6 register the fact that the breakpoint
 497          * was hit so the thread's debugger will see it.
 498          */
 499         for (i = 0; i < HBP_NUM; i++) {
 500                 if (thread->ptrace_bps[i] == bp)
 501                         break;
 502         }
 503
 504         thread->debugreg6 |= (DR_TRAP0 << i);
 505 }
 506
 507 /*
 508  * Walk through every ptrace breakpoints for this thread and
 509  * build the dr7 value on top of their attributes.
 510  *
 511  */
 512 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 513 {
 514         int i;
 515         int dr7 = 0;
 516         struct arch_hw_breakpoint *info;
 517
 518         for (i = 0; i < HBP_NUM; i++) {
 519                 if (bp[i] && !bp[i]->attr.disabled) {
 520                         info = counter_arch_bp(bp[i]);
 521                         dr7 |= encode_dr7(i, info->len, info->type);
 522                 }
 523         }
 524
 525         return dr7;
 526 }
 527
 528 static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
 529                                         int len, int type, bool disabled)
 530 {
 531         int err, bp_len, bp_type;
 532
 533         err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
 534         if (!err) {
 535                 attr->bp_len = bp_len;
 536                 attr->bp_type = bp_type;
 537                 attr->disabled = disabled;
 538         }
 539
 540         return err;
 541 }
 542
 543 static struct perf_event *
 544 ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
 545                                 unsigned long addr, bool disabled)
 546 {
 547         struct perf_event_attr attr;
 548         int err;
 549
 550         ptrace_breakpoint_init(&attr);
 551         attr.bp_addr = addr;
 552
 553         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 554         if (err)
 555                 return ERR_PTR(err);
 556
 557         return register_user_hw_breakpoint(&attr, ptrace_triggered,
 558                                                  NULL, tsk);
 559 }
 560
 561 static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 562                                         int disabled)
 563 {
 564         struct perf_event_attr attr = bp->attr;
 565         int err;
 566
 567         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 568         if (err)
 569                 return err;
 570
 571         return modify_user_hw_breakpoint(bp, &attr);
 572 }
 573
 574 /*
 575  * Handle ptrace writes to debug register 7.
 576  */
 577 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 578 {
 579         struct thread_struct *thread = &tsk->thread;
 580         unsigned long old_dr7;
 581         bool second_pass = false;
 582         int i, rc, ret = 0;
 583
 584         data &= ~DR_CONTROL_RESERVED;
 585         old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 586
 587 restore:
 588         rc = 0;
 589         for (i = 0; i < HBP_NUM; i++) {
 590                 unsigned len, type;
 591                 bool disabled = !decode_dr7(data, i, &len, &type);
 592                 struct perf_event *bp = thread->ptrace_bps[i];
 593
 594                 if (!bp) {
 595                         if (disabled)
 596                                 continue;
 597
 598                         bp = ptrace_register_breakpoint(tsk,
 599                                         len, type, 0, disabled);
 600                         if (IS_ERR(bp)) {
 601                                 rc = PTR_ERR(bp);
 602                                 break;
 603                         }
 604
 605                         thread->ptrace_bps[i] = bp;
 606                         continue;
 607                 }
 608
 609                 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
 610                 if (rc)
 611                         break;
 612         }
 613
 614         /* Restore if the first pass failed, second_pass shouldn't fail. */
 615         if (rc && !WARN_ON(second_pass)) {
 616                 ret = rc;
 617                 data = old_dr7;
 618                 second_pass = true;
 619                 goto restore;
 620         }
 621
 622         return ret;
 623 }
 624
 625 /*
 626  * Handle PTRACE_PEEKUSR calls for the debug register area.
 627  */
 628 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 629 {
 630         struct thread_struct *thread = &tsk->thread;
 631         unsigned long val = 0;
 632
 633         if (n < HBP_NUM) {
 634                 int index = array_index_nospec(n, HBP_NUM);
 635                 struct perf_event *bp = thread->ptrace_bps[index];
 636
 637                 if (bp)
 638                         val = bp->hw.info.address;
 639         } else if (n == 6) {
 640                 val = thread->debugreg6;
 641         } else if (n == 7) {
 642                 val = thread->ptrace_dr7;
 643         }
 644         return val;
 645 }
 646
 647 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 648                                       unsigned long addr)
 649 {
 650         struct thread_struct *t = &tsk->thread;
 651         struct perf_event *bp = t->ptrace_bps[nr];
 652         int err = 0;
 653
 654         if (!bp) {
 655                 /*
 656                  * Put stub len and type to create an inactive but correct bp.
 657                  *
 658                  * CHECKME: the previous code returned -EIO if the addr wasn't
 659                  * a valid task virtual addr. The new one will return -EINVAL in
 660                  *  this case.
 661                  * -EINVAL may be what we want for in-kernel breakpoints users,
 662                  * but -EIO looks better for ptrace, since we refuse a register
 663                  * writing for the user. And anyway this is the previous
 664                  * behaviour.
 665                  */
 666                 bp = ptrace_register_breakpoint(tsk,
 667                                 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
 668                                 addr, true);
 669                 if (IS_ERR(bp))
 670                         err = PTR_ERR(bp);
 671                 else
 672                         t->ptrace_bps[nr] = bp;
 673         } else {
 674                 struct perf_event_attr attr = bp->attr;
 675
 676                 attr.bp_addr = addr;
 677                 err = modify_user_hw_breakpoint(bp, &attr);
 678         }
 679
 680         return err;
 681 }
 682
 683 /*
 684  * Handle PTRACE_POKEUSR calls for the debug register area.
 685  */
 686 static int ptrace_set_debugreg(struct task_struct *tsk, int n,
 687                                unsigned long val)
 688 {
 689         struct thread_struct *thread = &tsk->thread;
 690         /* There are no DR4 or DR5 registers */
 691         int rc = -EIO;
 692
 693         if (n < HBP_NUM) {
 694                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
 695         } else if (n == 6) {
 696                 thread->debugreg6 = val;
 697                 rc = 0;
 698         } else if (n == 7) {
 699                 rc = ptrace_write_dr7(tsk, val);
 700                 if (!rc)
 701                         thread->ptrace_dr7 = val;
 702         }
 703         return rc;
 704 }
 705
 706 /*
 707  * These access the current or another (stopped) task's io permission
 708  * bitmap for debugging or core dump.
 709  */
 710 static int ioperm_active(struct task_struct *target,
 711                          const struct user_regset *regset)
 712 {
 713         struct io_bitmap *iobm = target->thread.io_bitmap;
 714
 715         return iobm ? DIV_ROUND_UP(iobm->max, regset->size) : 0;
 716 }
 717
 718 static int ioperm_get(struct task_struct *target,
 719                       const struct user_regset *regset,
 720                       unsigned int pos, unsigned int count,
 721                       void *kbuf, void __user *ubuf)
 722 {
 723         struct io_bitmap *iobm = target->thread.io_bitmap;
 724
 725         if (!iobm)
 726                 return -ENXIO;
 727
 728         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 729                                    iobm->bitmap, 0, IO_BITMAP_BYTES);
 730 }
 731
 732 /*
 733  * Called by kernel/ptrace.c when detaching..
 734  *
 735  * Make sure the single step bit is not set.
 736  */
 737 void ptrace_disable(struct task_struct *child)
 738 {
 739         user_disable_single_step(child);
 740 }
 741
 742 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 743 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 744 #endif
 745
 746 long arch_ptrace(struct task_struct *child, long request,
 747                  unsigned long addr, unsigned long data)
 748 {
 749         int ret;
 750         unsigned long __user *datap = (unsigned long __user *)data;
 751
 752         switch (request) {
 753         /* read the word at location addr in the USER area. */
 754         case PTRACE_PEEKUSR: {
 755                 unsigned long tmp;
 756
 757                 ret = -EIO;
 758                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 759                         break;
 760
 761                 tmp = 0;  /* Default return condition */
 762                 if (addr < sizeof(struct user_regs_struct))
 763                         tmp = getreg(child, addr);
 764                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 765                          addr <= offsetof(struct user, u_debugreg[7])) {
 766                         addr -= offsetof(struct user, u_debugreg[0]);
 767                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 768                 }
 769                 ret = put_user(tmp, datap);
 770                 break;
 771         }
 772
 773         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 774                 ret = -EIO;
 775                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 776                         break;
 777
 778                 if (addr < sizeof(struct user_regs_struct))
 779                         ret = putreg(child, addr, data);
 780                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 781                          addr <= offsetof(struct user, u_debugreg[7])) {
 782                         addr -= offsetof(struct user, u_debugreg[0]);
 783                         ret = ptrace_set_debugreg(child,
 784                                                   addr / sizeof(data), data);
 785                 }
 786                 break;
 787
 788         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 789                 return copy_regset_to_user(child,
 790                                            task_user_regset_view(current),
 791                                            REGSET_GENERAL,
 792                                            0, sizeof(struct user_regs_struct),
 793                                            datap);
 794
 795         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 796                 return copy_regset_from_user(child,
 797                                              task_user_regset_view(current),
 798                                              REGSET_GENERAL,
 799                                              0, sizeof(struct user_regs_struct),
 800                                              datap);
 801
 802         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 803                 return copy_regset_to_user(child,
 804                                            task_user_regset_view(current),
 805                                            REGSET_FP,
 806                                            0, sizeof(struct user_i387_struct),
 807                                            datap);
 808
 809         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 810                 return copy_regset_from_user(child,
 811                                              task_user_regset_view(current),
 812                                              REGSET_FP,
 813                                              0, sizeof(struct user_i387_struct),
 814                                              datap);
 815
 816 #ifdef CONFIG_X86_32
 817         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
 818                 return copy_regset_to_user(child, &user_x86_32_view,
 819                                            REGSET_XFP,
 820                                            0, sizeof(struct user_fxsr_struct),
 821                                            datap) ? -EIO : 0;
 822
 823         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
 824                 return copy_regset_from_user(child, &user_x86_32_view,
 825                                              REGSET_XFP,
 826                                              0, sizeof(struct user_fxsr_struct),
 827                                              datap) ? -EIO : 0;
 828 #endif
 829
 830 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 831         case PTRACE_GET_THREAD_AREA:
 832                 if ((int) addr < 0)
 833                         return -EIO;
 834                 ret = do_get_thread_area(child, addr,
 835                                         (struct user_desc __user *)data);
 836                 break;
 837
 838         case PTRACE_SET_THREAD_AREA:
 839                 if ((int) addr < 0)
 840                         return -EIO;
 841                 ret = do_set_thread_area(child, addr,
 842                                         (struct user_desc __user *)data, 0);
 843                 break;
 844 #endif
 845
 846 #ifdef CONFIG_X86_64
 847                 /* normal 64bit interface to access TLS data.
 848                    Works just like arch_prctl, except that the arguments
 849                    are reversed. */
 850         case PTRACE_ARCH_PRCTL:
 851                 ret = do_arch_prctl_64(child, data, addr);
 852                 break;
 853 #endif
 854
 855         default:
 856                 ret = ptrace_request(child, request, addr, data);
 857                 break;
 858         }
 859
 860         return ret;
 861 }
 862
 863 #ifdef CONFIG_IA32_EMULATION
 864
 865 #include <linux/compat.h>
 866 #include <linux/syscalls.h>
 867 #include <asm/ia32.h>
 868 #include <asm/user32.h>
 869
 870 #define R32(l,q)                                                        \
 871         case offsetof(struct user32, regs.l):                           \
 872                 regs->q = value; break
 873
 874 #define SEG32(rs)                                                       \
 875         case offsetof(struct user32, regs.rs):                          \
 876                 return set_segment_reg(child,                           \
 877                                        offsetof(struct user_regs_struct, rs), \
 878                                        value);                          \
 879                 break
 880
 881 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 882 {
 883         struct pt_regs *regs = task_pt_regs(child);
 884
 885         switch (regno) {
 886
 887         SEG32(cs);
 888         SEG32(ds);
 889         SEG32(es);
 890         SEG32(fs);
 891         SEG32(gs);
 892         SEG32(ss);
 893
 894         R32(ebx, bx);
 895         R32(ecx, cx);
 896         R32(edx, dx);
 897         R32(edi, di);
 898         R32(esi, si);
 899         R32(ebp, bp);
 900         R32(eax, ax);
 901         R32(eip, ip);
 902         R32(esp, sp);
 903
 904         case offsetof(struct user32, regs.orig_eax):
 905                 /*
 906                  * Warning: bizarre corner case fixup here.  A 32-bit
 907                  * debugger setting orig_eax to -1 wants to disable
 908                  * syscall restart.  Make sure that the syscall
 909                  * restart code sign-extends orig_ax.  Also make sure
 910                  * we interpret the -ERESTART* codes correctly if
 911                  * loaded into regs->ax in case the task is not
 912                  * actually still sitting at the exit from a 32-bit
 913                  * syscall with TS_COMPAT still set.
 914                  */
 915                 regs->orig_ax = value;
 916                 if (syscall_get_nr(child, regs) >= 0)
 917                         child->thread_info.status |= TS_I386_REGS_POKED;
 918                 break;
 919
 920         case offsetof(struct user32, regs.eflags):
 921                 return set_flags(child, value);
 922
 923         case offsetof(struct user32, u_debugreg[0]) ...
 924                 offsetof(struct user32, u_debugreg[7]):
 925                 regno -= offsetof(struct user32, u_debugreg[0]);
 926                 return ptrace_set_debugreg(child, regno / 4, value);
 927
 928         default:
 929                 if (regno > sizeof(struct user32) || (regno & 3))
 930                         return -EIO;
 931
 932                 /*
 933                  * Other dummy fields in the virtual user structure
 934                  * are ignored
 935                  */
 936                 break;
 937         }
 938         return 0;
 939 }
 940
 941 #undef R32
 942 #undef SEG32
 943
 944 #define R32(l,q)                                                        \
 945         case offsetof(struct user32, regs.l):                           \
 946                 *val = regs->q; break
 947
 948 #define SEG32(rs)                                                       \
 949         case offsetof(struct user32, regs.rs):                          \
 950                 *val = get_segment_reg(child,                           \
 951                                        offsetof(struct user_regs_struct, rs)); \
 952                 break
 953
 954 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 955 {
 956         struct pt_regs *regs = task_pt_regs(child);
 957
 958         switch (regno) {
 959
 960         SEG32(ds);
 961         SEG32(es);
 962         SEG32(fs);
 963         SEG32(gs);
 964
 965         R32(cs, cs);
 966         R32(ss, ss);
 967         R32(ebx, bx);
 968         R32(ecx, cx);
 969         R32(edx, dx);
 970         R32(edi, di);
 971         R32(esi, si);
 972         R32(ebp, bp);
 973         R32(eax, ax);
 974         R32(orig_eax, orig_ax);
 975         R32(eip, ip);
 976         R32(esp, sp);
 977
 978         case offsetof(struct user32, regs.eflags):
 979                 *val = get_flags(child);
 980                 break;
 981
 982         case offsetof(struct user32, u_debugreg[0]) ...
 983                 offsetof(struct user32, u_debugreg[7]):
 984                 regno -= offsetof(struct user32, u_debugreg[0]);
 985                 *val = ptrace_get_debugreg(child, regno / 4);
 986                 break;
 987
 988         default:
 989                 if (regno > sizeof(struct user32) || (regno & 3))
 990                         return -EIO;
 991
 992                 /*
 993                  * Other dummy fields in the virtual user structure
 994                  * are ignored
 995                  */
 996                 *val = 0;
 997                 break;
 998         }
 999         return 0;
1000 }
1001
1002 #undef R32
1003 #undef SEG32
1004
1005 static int genregs32_get(struct task_struct *target,
1006                          const struct user_regset *regset,
1007                          unsigned int pos, unsigned int count,
1008                          void *kbuf, void __user *ubuf)
1009 {
1010         if (kbuf) {
1011                 compat_ulong_t *k = kbuf;
1012                 while (count >= sizeof(*k)) {
1013                         getreg32(target, pos, k++);
1014                         count -= sizeof(*k);
1015                         pos += sizeof(*k);
1016                 }
1017         } else {
1018                 compat_ulong_t __user *u = ubuf;
1019                 while (count >= sizeof(*u)) {
1020                         compat_ulong_t word;
1021                         getreg32(target, pos, &word);
1022                         if (__put_user(word, u++))
1023                                 return -EFAULT;
1024                         count -= sizeof(*u);
1025                         pos += sizeof(*u);
1026                 }
1027         }
1028
1029         return 0;
1030 }
1031
1032 static int genregs32_set(struct task_struct *target,
1033                          const struct user_regset *regset,
1034                          unsigned int pos, unsigned int count,
1035                          const void *kbuf, const void __user *ubuf)
1036 {
1037         int ret = 0;
1038         if (kbuf) {
1039                 const compat_ulong_t *k = kbuf;
1040                 while (count >= sizeof(*k) && !ret) {
1041                         ret = putreg32(target, pos, *k++);
1042                         count -= sizeof(*k);
1043                         pos += sizeof(*k);
1044                 }
1045         } else {
1046                 const compat_ulong_t __user *u = ubuf;
1047                 while (count >= sizeof(*u) && !ret) {
1048                         compat_ulong_t word;
1049                         ret = __get_user(word, u++);
1050                         if (ret)
1051                                 break;
1052                         ret = putreg32(target, pos, word);
1053                         count -= sizeof(*u);
1054                         pos += sizeof(*u);
1055                 }
1056         }
1057         return ret;
1058 }
1059
1060 static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1061                              compat_ulong_t caddr, compat_ulong_t cdata)
1062 {
1063         unsigned long addr = caddr;
1064         unsigned long data = cdata;
1065         void __user *datap = compat_ptr(data);
1066         int ret;
1067         __u32 val;
1068
1069         switch (request) {
1070         case PTRACE_PEEKUSR:
1071                 ret = getreg32(child, addr, &val);
1072                 if (ret == 0)
1073                         ret = put_user(val, (__u32 __user *)datap);
1074                 break;
1075
1076         case PTRACE_POKEUSR:
1077                 ret = putreg32(child, addr, data);
1078                 break;
1079
1080         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1081                 return copy_regset_to_user(child, &user_x86_32_view,
1082                                            REGSET_GENERAL,
1083                                            0, sizeof(struct user_regs_struct32),
1084                                            datap);
1085
1086         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1087                 return copy_regset_from_user(child, &user_x86_32_view,
1088                                              REGSET_GENERAL, 0,
1089                                              sizeof(struct user_regs_struct32),
1090                                              datap);
1091
1092         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1093                 return copy_regset_to_user(child, &user_x86_32_view,
1094                                            REGSET_FP, 0,
1095                                            sizeof(struct user_i387_ia32_struct),
1096                                            datap);
1097
1098         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1099                 return copy_regset_from_user(
1100                         child, &user_x86_32_view, REGSET_FP,
1101                         0, sizeof(struct user_i387_ia32_struct), datap);
1102
1103         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1104                 return copy_regset_to_user(child, &user_x86_32_view,
1105                                            REGSET_XFP, 0,
1106                                            sizeof(struct user32_fxsr_struct),
1107                                            datap);
1108
1109         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1110                 return copy_regset_from_user(child, &user_x86_32_view,
1111                                              REGSET_XFP, 0,
1112                                              sizeof(struct user32_fxsr_struct),
1113                                              datap);
1114
1115         case PTRACE_GET_THREAD_AREA:
1116         case PTRACE_SET_THREAD_AREA:
1117                 return arch_ptrace(child, request, addr, data);
1118
1119         default:
1120                 return compat_ptrace_request(child, request, addr, data);
1121         }
1122
1123         return ret;
1124 }
1125 #endif /* CONFIG_IA32_EMULATION */
1126
1127 #ifdef CONFIG_X86_X32_ABI
1128 static long x32_arch_ptrace(struct task_struct *child,
1129                             compat_long_t request, compat_ulong_t caddr,
1130                             compat_ulong_t cdata)
1131 {
1132         unsigned long addr = caddr;
1133         unsigned long data = cdata;
1134         void __user *datap = compat_ptr(data);
1135         int ret;
1136
1137         switch (request) {
1138         /* Read 32bits at location addr in the USER area.  Only allow
1139            to return the lower 32bits of segment and debug registers.  */
1140         case PTRACE_PEEKUSR: {
1141                 u32 tmp;
1142
1143                 ret = -EIO;
1144                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1145                     addr < offsetof(struct user_regs_struct, cs))
1146                         break;
1147
1148                 tmp = 0;  /* Default return condition */
1149                 if (addr < sizeof(struct user_regs_struct))
1150                         tmp = getreg(child, addr);
1151                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1152                          addr <= offsetof(struct user, u_debugreg[7])) {
1153                         addr -= offsetof(struct user, u_debugreg[0]);
1154                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1155                 }
1156                 ret = put_user(tmp, (__u32 __user *)datap);
1157                 break;
1158         }
1159
1160         /* Write the word at location addr in the USER area.  Only allow
1161            to update segment and debug registers with the upper 32bits
1162            zero-extended. */
1163         case PTRACE_POKEUSR:
1164                 ret = -EIO;
1165                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1166                     addr < offsetof(struct user_regs_struct, cs))
1167                         break;
1168
1169                 if (addr < sizeof(struct user_regs_struct))
1170                         ret = putreg(child, addr, data);
1171                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1172                          addr <= offsetof(struct user, u_debugreg[7])) {
1173                         addr -= offsetof(struct user, u_debugreg[0]);
1174                         ret = ptrace_set_debugreg(child,
1175                                                   addr / sizeof(data), data);
1176                 }
1177                 break;
1178
1179         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1180                 return copy_regset_to_user(child,
1181                                            task_user_regset_view(current),
1182                                            REGSET_GENERAL,
1183                                            0, sizeof(struct user_regs_struct),
1184                                            datap);
1185
1186         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1187                 return copy_regset_from_user(child,
1188                                              task_user_regset_view(current),
1189                                              REGSET_GENERAL,
1190                                              0, sizeof(struct user_regs_struct),
1191                                              datap);
1192
1193         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1194                 return copy_regset_to_user(child,
1195                                            task_user_regset_view(current),
1196                                            REGSET_FP,
1197                                            0, sizeof(struct user_i387_struct),
1198                                            datap);
1199
1200         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1201                 return copy_regset_from_user(child,
1202                                              task_user_regset_view(current),
1203                                              REGSET_FP,
1204                                              0, sizeof(struct user_i387_struct),
1205                                              datap);
1206
1207         default:
1208                 return compat_ptrace_request(child, request, addr, data);
1209         }
1210
1211         return ret;
1212 }
1213 #endif
1214
1215 #ifdef CONFIG_COMPAT
1216 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1217                         compat_ulong_t caddr, compat_ulong_t cdata)
1218 {
1219 #ifdef CONFIG_X86_X32_ABI
1220         if (!in_ia32_syscall())
1221                 return x32_arch_ptrace(child, request, caddr, cdata);
1222 #endif
1223 #ifdef CONFIG_IA32_EMULATION
1224         return ia32_arch_ptrace(child, request, caddr, cdata);
1225 #else
1226         return 0;
1227 #endif
1228 }
1229 #endif  /* CONFIG_COMPAT */
1230
1231 #ifdef CONFIG_X86_64
1232
1233 static struct user_regset x86_64_regsets[] __ro_after_init = {
1234         [REGSET_GENERAL] = {
1235                 .core_note_type = NT_PRSTATUS,
1236                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1237                 .size = sizeof(long), .align = sizeof(long),
1238                 .get = genregs_get, .set = genregs_set
1239         },
1240         [REGSET_FP] = {
1241                 .core_note_type = NT_PRFPREG,
1242                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1243                 .size = sizeof(long), .align = sizeof(long),
1244                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1245         },
1246         [REGSET_XSTATE] = {
1247                 .core_note_type = NT_X86_XSTATE,
1248                 .size = sizeof(u64), .align = sizeof(u64),
1249                 .active = xstateregs_active, .get = xstateregs_get,
1250                 .set = xstateregs_set
1251         },
1252         [REGSET_IOPERM64] = {
1253                 .core_note_type = NT_386_IOPERM,
1254                 .n = IO_BITMAP_LONGS,
1255                 .size = sizeof(long), .align = sizeof(long),
1256                 .active = ioperm_active, .get = ioperm_get
1257         },
1258 };
1259
1260 static const struct user_regset_view user_x86_64_view = {
1261         .name = "x86_64", .e_machine = EM_X86_64,
1262         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1263 };
1264
1265 #else  /* CONFIG_X86_32 */
1266
1267 #define user_regs_struct32      user_regs_struct
1268 #define genregs32_get           genregs_get
1269 #define genregs32_set           genregs_set
1270
1271 #endif  /* CONFIG_X86_64 */
1272
1273 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1274 static struct user_regset x86_32_regsets[] __ro_after_init = {
1275         [REGSET_GENERAL] = {
1276                 .core_note_type = NT_PRSTATUS,
1277                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1278                 .size = sizeof(u32), .align = sizeof(u32),
1279                 .get = genregs32_get, .set = genregs32_set
1280         },
1281         [REGSET_FP] = {
1282                 .core_note_type = NT_PRFPREG,
1283                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1284                 .size = sizeof(u32), .align = sizeof(u32),
1285                 .active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1286         },
1287         [REGSET_XFP] = {
1288                 .core_note_type = NT_PRXFPREG,
1289                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1290                 .size = sizeof(u32), .align = sizeof(u32),
1291                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1292         },
1293         [REGSET_XSTATE] = {
1294                 .core_note_type = NT_X86_XSTATE,
1295                 .size = sizeof(u64), .align = sizeof(u64),
1296                 .active = xstateregs_active, .get = xstateregs_get,
1297                 .set = xstateregs_set
1298         },
1299         [REGSET_TLS] = {
1300                 .core_note_type = NT_386_TLS,
1301                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1302                 .size = sizeof(struct user_desc),
1303                 .align = sizeof(struct user_desc),
1304                 .active = regset_tls_active,
1305                 .get = regset_tls_get, .set = regset_tls_set
1306         },
1307         [REGSET_IOPERM32] = {
1308                 .core_note_type = NT_386_IOPERM,
1309                 .n = IO_BITMAP_BYTES / sizeof(u32),
1310                 .size = sizeof(u32), .align = sizeof(u32),
1311                 .active = ioperm_active, .get = ioperm_get
1312         },
1313 };
1314
1315 static const struct user_regset_view user_x86_32_view = {
1316         .name = "i386", .e_machine = EM_386,
1317         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1318 };
1319 #endif
1320
1321 /*
1322  * This represents bytes 464..511 in the memory layout exported through
1323  * the REGSET_XSTATE interface.
1324  */
1325 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1326
1327 void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1328 {
1329 #ifdef CONFIG_X86_64
1330         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1331 #endif
1332 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1333         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1334 #endif
1335         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1336 }
1337
1338 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1339 {
1340 #ifdef CONFIG_IA32_EMULATION
1341         if (!user_64bit_mode(task_pt_regs(task)))
1342 #endif
1343 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1344                 return &user_x86_32_view;
1345 #endif
1346 #ifdef CONFIG_X86_64
1347         return &user_x86_64_view;
1348 #endif
1349 }
1350
1351 void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
1352 {
1353         struct task_struct *tsk = current;
1354
1355         tsk->thread.trap_nr = X86_TRAP_DB;
1356         tsk->thread.error_code = error_code;
1357
1358         /* Send us the fake SIGTRAP */
1359         force_sig_fault(SIGTRAP, si_code,
1360                         user_mode(regs) ? (void __user *)regs->ip : NULL);
1361 }
1362
1363 void user_single_step_report(struct pt_regs *regs)
1364 {
1365         send_sigtrap(regs, 0, TRAP_BRKPT);
1366 }