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