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