arch/x86/kernel/ptrace.c

   1 /* By Ross Biro 1/23/92 */
   2 /*
   3  * Pentium III FXSR, SSE support
   4  *      Gareth Hughes <gareth@valinux.com>, May 2000
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/sched.h>
   9 #include <linux/mm.h>
  10 #include <linux/smp.h>
  11 #include <linux/errno.h>
  12 #include <linux/slab.h>
  13 #include <linux/ptrace.h>
  14 #include <linux/tracehook.h>
  15 #include <linux/user.h>
  16 #include <linux/elf.h>
  17 #include <linux/security.h>
  18 #include <linux/audit.h>
  19 #include <linux/seccomp.h>
  20 #include <linux/signal.h>
  21 #include <linux/perf_event.h>
  22 #include <linux/hw_breakpoint.h>
  23 #include <linux/rcupdate.h>
  24 #include <linux/export.h>
  25 #include <linux/context_tracking.h>
  26
  27 #include <asm/uaccess.h>
  28 #include <asm/pgtable.h>
  29 #include <asm/processor.h>
  30 #include <asm/fpu/internal.h>
  31 #include <asm/fpu/signal.h>
  32 #include <asm/fpu/regset.h>
  33 #include <asm/debugreg.h>
  34 #include <asm/ldt.h>
  35 #include <asm/desc.h>
  36 #include <asm/prctl.h>
  37 #include <asm/proto.h>
  38 #include <asm/hw_breakpoint.h>
  39 #include <asm/traps.h>
  40 #include <asm/syscall.h>
  41
  42 #include "tls.h"
  43
  44 enum x86_regset {
  45         REGSET_GENERAL,
  46         REGSET_FP,
  47         REGSET_XFP,
  48         REGSET_IOPERM64 = REGSET_XFP,
  49         REGSET_XSTATE,
  50         REGSET_TLS,
  51         REGSET_IOPERM32,
  52 };
  53
  54 struct pt_regs_offset {
  55         const char *name;
  56         int offset;
  57 };
  58
  59 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  60 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  61
  62 static const struct pt_regs_offset regoffset_table[] = {
  63 #ifdef CONFIG_X86_64
  64         REG_OFFSET_NAME(r15),
  65         REG_OFFSET_NAME(r14),
  66         REG_OFFSET_NAME(r13),
  67         REG_OFFSET_NAME(r12),
  68         REG_OFFSET_NAME(r11),
  69         REG_OFFSET_NAME(r10),
  70         REG_OFFSET_NAME(r9),
  71         REG_OFFSET_NAME(r8),
  72 #endif
  73         REG_OFFSET_NAME(bx),
  74         REG_OFFSET_NAME(cx),
  75         REG_OFFSET_NAME(dx),
  76         REG_OFFSET_NAME(si),
  77         REG_OFFSET_NAME(di),
  78         REG_OFFSET_NAME(bp),
  79         REG_OFFSET_NAME(ax),
  80 #ifdef CONFIG_X86_32
  81         REG_OFFSET_NAME(ds),
  82         REG_OFFSET_NAME(es),
  83         REG_OFFSET_NAME(fs),
  84         REG_OFFSET_NAME(gs),
  85 #endif
  86         REG_OFFSET_NAME(orig_ax),
  87         REG_OFFSET_NAME(ip),
  88         REG_OFFSET_NAME(cs),
  89         REG_OFFSET_NAME(flags),
  90         REG_OFFSET_NAME(sp),
  91         REG_OFFSET_NAME(ss),
  92         REG_OFFSET_END,
  93 };
  94
  95 /**
  96  * regs_query_register_offset() - query register offset from its name
  97  * @name:       the name of a register
  98  *
  99  * regs_query_register_offset() returns the offset of a register in struct
 100  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 101  */
 102 int regs_query_register_offset(const char *name)
 103 {
 104         const struct pt_regs_offset *roff;
 105         for (roff = regoffset_table; roff->name != NULL; roff++)
 106                 if (!strcmp(roff->name, name))
 107                         return roff->offset;
 108         return -EINVAL;
 109 }
 110
 111 /**
 112  * regs_query_register_name() - query register name from its offset
 113  * @offset:     the offset of a register in struct pt_regs.
 114  *
 115  * regs_query_register_name() returns the name of a register from its
 116  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 117  */
 118 const char *regs_query_register_name(unsigned int offset)
 119 {
 120         const struct pt_regs_offset *roff;
 121         for (roff = regoffset_table; roff->name != NULL; roff++)
 122                 if (roff->offset == offset)
 123                         return roff->name;
 124         return NULL;
 125 }
 126
 127 /*
 128  * does not yet catch signals sent when the child dies.
 129  * in exit.c or in signal.c.
 130  */
 131
 132 /*
 133  * Determines which flags the user has access to [1 = access, 0 = no access].
 134  */
 135 #define FLAG_MASK_32            ((unsigned long)                        \
 136                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
 137                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
 138                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
 139                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
 140                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
 141
 142 /*
 143  * Determines whether a value may be installed in a segment register.
 144  */
 145 static inline bool invalid_selector(u16 value)
 146 {
 147         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
 148 }
 149
 150 #ifdef CONFIG_X86_32
 151
 152 #define FLAG_MASK               FLAG_MASK_32
 153
 154 /*
 155  * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
 156  * when it traps.  The previous stack will be directly underneath the saved
 157  * registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
 158  *
 159  * Now, if the stack is empty, '&regs->sp' is out of range. In this
 160  * case we try to take the previous stack. To always return a non-null
 161  * stack pointer we fall back to regs as stack if no previous stack
 162  * exists.
 163  *
 164  * This is valid only for kernel mode traps.
 165  */
 166 unsigned long kernel_stack_pointer(struct pt_regs *regs)
 167 {
 168         unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
 169         unsigned long sp = (unsigned long)&regs->sp;
 170         u32 *prev_esp;
 171
 172         if (context == (sp & ~(THREAD_SIZE - 1)))
 173                 return sp;
 174
 175         prev_esp = (u32 *)(context);
 176         if (*prev_esp)
 177                 return (unsigned long)*prev_esp;
 178
 179         return (unsigned long)regs;
 180 }
 181 EXPORT_SYMBOL_GPL(kernel_stack_pointer);
 182
 183 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 184 {
 185         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 186         return &regs->bx + (regno >> 2);
 187 }
 188
 189 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 190 {
 191         /*
 192          * Returning the value truncates it to 16 bits.
 193          */
 194         unsigned int retval;
 195         if (offset != offsetof(struct user_regs_struct, gs))
 196                 retval = *pt_regs_access(task_pt_regs(task), offset);
 197         else {
 198                 if (task == current)
 199                         retval = get_user_gs(task_pt_regs(task));
 200                 else
 201                         retval = task_user_gs(task);
 202         }
 203         return retval;
 204 }
 205
 206 static int set_segment_reg(struct task_struct *task,
 207                            unsigned long offset, u16 value)
 208 {
 209         /*
 210          * The value argument was already truncated to 16 bits.
 211          */
 212         if (invalid_selector(value))
 213                 return -EIO;
 214
 215         /*
 216          * For %cs and %ss we cannot permit a null selector.
 217          * We can permit a bogus selector as long as it has USER_RPL.
 218          * Null selectors are fine for other segment registers, but
 219          * we will never get back to user mode with invalid %cs or %ss
 220          * and will take the trap in iret instead.  Much code relies
 221          * on user_mode() to distinguish a user trap frame (which can
 222          * safely use invalid selectors) from a kernel trap frame.
 223          */
 224         switch (offset) {
 225         case offsetof(struct user_regs_struct, cs):
 226         case offsetof(struct user_regs_struct, ss):
 227                 if (unlikely(value == 0))
 228                         return -EIO;
 229
 230         default:
 231                 *pt_regs_access(task_pt_regs(task), offset) = value;
 232                 break;
 233
 234         case offsetof(struct user_regs_struct, gs):
 235                 if (task == current)
 236                         set_user_gs(task_pt_regs(task), value);
 237                 else
 238                         task_user_gs(task) = value;
 239         }
 240
 241         return 0;
 242 }
 243
 244 #else  /* CONFIG_X86_64 */
 245
 246 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
 247
 248 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 249 {
 250         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 251         return &regs->r15 + (offset / sizeof(regs->r15));
 252 }
 253
 254 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 255 {
 256         /*
 257          * Returning the value truncates it to 16 bits.
 258          */
 259         unsigned int seg;
 260
 261         switch (offset) {
 262         case offsetof(struct user_regs_struct, fs):
 263                 if (task == current) {
 264                         /* Older gas can't assemble movq %?s,%r?? */
 265                         asm("movl %%fs,%0" : "=r" (seg));
 266                         return seg;
 267                 }
 268                 return task->thread.fsindex;
 269         case offsetof(struct user_regs_struct, gs):
 270                 if (task == current) {
 271                         asm("movl %%gs,%0" : "=r" (seg));
 272                         return seg;
 273                 }
 274                 return task->thread.gsindex;
 275         case offsetof(struct user_regs_struct, ds):
 276                 if (task == current) {
 277                         asm("movl %%ds,%0" : "=r" (seg));
 278                         return seg;
 279                 }
 280                 return task->thread.ds;
 281         case offsetof(struct user_regs_struct, es):
 282                 if (task == current) {
 283                         asm("movl %%es,%0" : "=r" (seg));
 284                         return seg;
 285                 }
 286                 return task->thread.es;
 287
 288         case offsetof(struct user_regs_struct, cs):
 289         case offsetof(struct user_regs_struct, ss):
 290                 break;
 291         }
 292         return *pt_regs_access(task_pt_regs(task), offset);
 293 }
 294
 295 static int set_segment_reg(struct task_struct *task,
 296                            unsigned long offset, u16 value)
 297 {
 298         /*
 299          * The value argument was already truncated to 16 bits.
 300          */
 301         if (invalid_selector(value))
 302                 return -EIO;
 303
 304         switch (offset) {
 305         case offsetof(struct user_regs_struct,fs):
 306                 task->thread.fsindex = value;
 307                 if (task == current)
 308                         loadsegment(fs, task->thread.fsindex);
 309                 break;
 310         case offsetof(struct user_regs_struct,gs):
 311                 task->thread.gsindex = value;
 312                 if (task == current)
 313                         load_gs_index(task->thread.gsindex);
 314                 break;
 315         case offsetof(struct user_regs_struct,ds):
 316                 task->thread.ds = value;
 317                 if (task == current)
 318                         loadsegment(ds, task->thread.ds);
 319                 break;
 320         case offsetof(struct user_regs_struct,es):
 321                 task->thread.es = value;
 322                 if (task == current)
 323                         loadsegment(es, task->thread.es);
 324                 break;
 325
 326                 /*
 327                  * Can't actually change these in 64-bit mode.
 328                  */
 329         case offsetof(struct user_regs_struct,cs):
 330                 if (unlikely(value == 0))
 331                         return -EIO;
 332                 task_pt_regs(task)->cs = value;
 333                 break;
 334         case offsetof(struct user_regs_struct,ss):
 335                 if (unlikely(value == 0))
 336                         return -EIO;
 337                 task_pt_regs(task)->ss = value;
 338                 break;
 339         }
 340
 341         return 0;
 342 }
 343
 344 #endif  /* CONFIG_X86_32 */
 345
 346 static unsigned long get_flags(struct task_struct *task)
 347 {
 348         unsigned long retval = task_pt_regs(task)->flags;
 349
 350         /*
 351          * If the debugger set TF, hide it from the readout.
 352          */
 353         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 354                 retval &= ~X86_EFLAGS_TF;
 355
 356         return retval;
 357 }
 358
 359 static int set_flags(struct task_struct *task, unsigned long value)
 360 {
 361         struct pt_regs *regs = task_pt_regs(task);
 362
 363         /*
 364          * If the user value contains TF, mark that
 365          * it was not "us" (the debugger) that set it.
 366          * If not, make sure it stays set if we had.
 367          */
 368         if (value & X86_EFLAGS_TF)
 369                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
 370         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 371                 value |= X86_EFLAGS_TF;
 372
 373         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 374
 375         return 0;
 376 }
 377
 378 static int putreg(struct task_struct *child,
 379                   unsigned long offset, unsigned long value)
 380 {
 381         switch (offset) {
 382         case offsetof(struct user_regs_struct, cs):
 383         case offsetof(struct user_regs_struct, ds):
 384         case offsetof(struct user_regs_struct, es):
 385         case offsetof(struct user_regs_struct, fs):
 386         case offsetof(struct user_regs_struct, gs):
 387         case offsetof(struct user_regs_struct, ss):
 388                 return set_segment_reg(child, offset, value);
 389
 390         case offsetof(struct user_regs_struct, flags):
 391                 return set_flags(child, value);
 392
 393 #ifdef CONFIG_X86_64
 394         case offsetof(struct user_regs_struct,fs_base):
 395                 if (value >= TASK_SIZE_MAX)
 396                         return -EIO;
 397                 /*
 398                  * When changing the segment base, use do_arch_prctl
 399                  * to set either thread.fs or thread.fsindex and the
 400                  * corresponding GDT slot.
 401                  */
 402                 if (child->thread.fsbase != value)
 403                         return do_arch_prctl(child, ARCH_SET_FS, value);
 404                 return 0;
 405         case offsetof(struct user_regs_struct,gs_base):
 406                 /*
 407                  * Exactly the same here as the %fs handling above.
 408                  */
 409                 if (value >= TASK_SIZE_MAX)
 410                         return -EIO;
 411                 if (child->thread.gsbase != value)
 412                         return do_arch_prctl(child, ARCH_SET_GS, value);
 413                 return 0;
 414 #endif
 415         }
 416
 417         *pt_regs_access(task_pt_regs(child), offset) = value;
 418         return 0;
 419 }
 420
 421 static unsigned long getreg(struct task_struct *task, unsigned long offset)
 422 {
 423         switch (offset) {
 424         case offsetof(struct user_regs_struct, cs):
 425         case offsetof(struct user_regs_struct, ds):
 426         case offsetof(struct user_regs_struct, es):
 427         case offsetof(struct user_regs_struct, fs):
 428         case offsetof(struct user_regs_struct, gs):
 429         case offsetof(struct user_regs_struct, ss):
 430                 return get_segment_reg(task, offset);
 431
 432         case offsetof(struct user_regs_struct, flags):
 433                 return get_flags(task);
 434
 435 #ifdef CONFIG_X86_64
 436         case offsetof(struct user_regs_struct, fs_base): {
 437                 /*
 438                  * XXX: This will not behave as expected if called on
 439                  * current or if fsindex != 0.
 440                  */
 441                 return task->thread.fsbase;
 442         }
 443         case offsetof(struct user_regs_struct, gs_base): {
 444                 /*
 445                  * XXX: This will not behave as expected if called on
 446                  * current or if fsindex != 0.
 447                  */
 448                 return task->thread.gsbase;
 449         }
 450 #endif
 451         }
 452
 453         return *pt_regs_access(task_pt_regs(task), offset);
 454 }
 455
 456 static int genregs_get(struct task_struct *target,
 457                        const struct user_regset *regset,
 458                        unsigned int pos, unsigned int count,
 459                        void *kbuf, void __user *ubuf)
 460 {
 461         if (kbuf) {
 462                 unsigned long *k = kbuf;
 463                 while (count >= sizeof(*k)) {
 464                         *k++ = getreg(target, pos);
 465                         count -= sizeof(*k);
 466                         pos += sizeof(*k);
 467                 }
 468         } else {
 469                 unsigned long __user *u = ubuf;
 470                 while (count >= sizeof(*u)) {
 471                         if (__put_user(getreg(target, pos), u++))
 472                                 return -EFAULT;
 473                         count -= sizeof(*u);
 474                         pos += sizeof(*u);
 475                 }
 476         }
 477
 478         return 0;
 479 }
 480
 481 static int genregs_set(struct task_struct *target,
 482                        const struct user_regset *regset,
 483                        unsigned int pos, unsigned int count,
 484                        const void *kbuf, const void __user *ubuf)
 485 {
 486         int ret = 0;
 487         if (kbuf) {
 488                 const unsigned long *k = kbuf;
 489                 while (count >= sizeof(*k) && !ret) {
 490                         ret = putreg(target, pos, *k++);
 491                         count -= sizeof(*k);
 492                         pos += sizeof(*k);
 493                 }
 494         } else {
 495                 const unsigned long  __user *u = ubuf;
 496                 while (count >= sizeof(*u) && !ret) {
 497                         unsigned long word;
 498                         ret = __get_user(word, u++);
 499                         if (ret)
 500                                 break;
 501                         ret = putreg(target, pos, word);
 502                         count -= sizeof(*u);
 503                         pos += sizeof(*u);
 504                 }
 505         }
 506         return ret;
 507 }
 508
 509 static void ptrace_triggered(struct perf_event *bp,
 510                              struct perf_sample_data *data,
 511                              struct pt_regs *regs)
 512 {
 513         int i;
 514         struct thread_struct *thread = &(current->thread);
 515
 516         /*
 517          * Store in the virtual DR6 register the fact that the breakpoint
 518          * was hit so the thread's debugger will see it.
 519          */
 520         for (i = 0; i < HBP_NUM; i++) {
 521                 if (thread->ptrace_bps[i] == bp)
 522                         break;
 523         }
 524
 525         thread->debugreg6 |= (DR_TRAP0 << i);
 526 }
 527
 528 /*
 529  * Walk through every ptrace breakpoints for this thread and
 530  * build the dr7 value on top of their attributes.
 531  *
 532  */
 533 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 534 {
 535         int i;
 536         int dr7 = 0;
 537         struct arch_hw_breakpoint *info;
 538
 539         for (i = 0; i < HBP_NUM; i++) {
 540                 if (bp[i] && !bp[i]->attr.disabled) {
 541                         info = counter_arch_bp(bp[i]);
 542                         dr7 |= encode_dr7(i, info->len, info->type);
 543                 }
 544         }
 545
 546         return dr7;
 547 }
 548
 549 static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
 550                                         int len, int type, bool disabled)
 551 {
 552         int err, bp_len, bp_type;
 553
 554         err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
 555         if (!err) {
 556                 attr->bp_len = bp_len;
 557                 attr->bp_type = bp_type;
 558                 attr->disabled = disabled;
 559         }
 560
 561         return err;
 562 }
 563
 564 static struct perf_event *
 565 ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
 566                                 unsigned long addr, bool disabled)
 567 {
 568         struct perf_event_attr attr;
 569         int err;
 570
 571         ptrace_breakpoint_init(&attr);
 572         attr.bp_addr = addr;
 573
 574         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 575         if (err)
 576                 return ERR_PTR(err);
 577
 578         return register_user_hw_breakpoint(&attr, ptrace_triggered,
 579                                                  NULL, tsk);
 580 }
 581
 582 static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 583                                         int disabled)
 584 {
 585         struct perf_event_attr attr = bp->attr;
 586         int err;
 587
 588         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 589         if (err)
 590                 return err;
 591
 592         return modify_user_hw_breakpoint(bp, &attr);
 593 }
 594
 595 /*
 596  * Handle ptrace writes to debug register 7.
 597  */
 598 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 599 {
 600         struct thread_struct *thread = &tsk->thread;
 601         unsigned long old_dr7;
 602         bool second_pass = false;
 603         int i, rc, ret = 0;
 604
 605         data &= ~DR_CONTROL_RESERVED;
 606         old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 607
 608 restore:
 609         rc = 0;
 610         for (i = 0; i < HBP_NUM; i++) {
 611                 unsigned len, type;
 612                 bool disabled = !decode_dr7(data, i, &len, &type);
 613                 struct perf_event *bp = thread->ptrace_bps[i];
 614
 615                 if (!bp) {
 616                         if (disabled)
 617                                 continue;
 618
 619                         bp = ptrace_register_breakpoint(tsk,
 620                                         len, type, 0, disabled);
 621                         if (IS_ERR(bp)) {
 622                                 rc = PTR_ERR(bp);
 623                                 break;
 624                         }
 625
 626                         thread->ptrace_bps[i] = bp;
 627                         continue;
 628                 }
 629
 630                 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
 631                 if (rc)
 632                         break;
 633         }
 634
 635         /* Restore if the first pass failed, second_pass shouldn't fail. */
 636         if (rc && !WARN_ON(second_pass)) {
 637                 ret = rc;
 638                 data = old_dr7;
 639                 second_pass = true;
 640                 goto restore;
 641         }
 642
 643         return ret;
 644 }
 645
 646 /*
 647  * Handle PTRACE_PEEKUSR calls for the debug register area.
 648  */
 649 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 650 {
 651         struct thread_struct *thread = &tsk->thread;
 652         unsigned long val = 0;
 653
 654         if (n < HBP_NUM) {
 655                 struct perf_event *bp = thread->ptrace_bps[n];
 656
 657                 if (bp)
 658                         val = bp->hw.info.address;
 659         } else if (n == 6) {
 660                 val = thread->debugreg6;
 661         } else if (n == 7) {
 662                 val = thread->ptrace_dr7;
 663         }
 664         return val;
 665 }
 666
 667 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 668                                       unsigned long addr)
 669 {
 670         struct thread_struct *t = &tsk->thread;
 671         struct perf_event *bp = t->ptrace_bps[nr];
 672         int err = 0;
 673
 674         if (!bp) {
 675                 /*
 676                  * Put stub len and type to create an inactive but correct bp.
 677                  *
 678                  * CHECKME: the previous code returned -EIO if the addr wasn't
 679                  * a valid task virtual addr. The new one will return -EINVAL in
 680                  *  this case.
 681                  * -EINVAL may be what we want for in-kernel breakpoints users,
 682                  * but -EIO looks better for ptrace, since we refuse a register
 683                  * writing for the user. And anyway this is the previous
 684                  * behaviour.
 685                  */
 686                 bp = ptrace_register_breakpoint(tsk,
 687                                 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
 688                                 addr, true);
 689                 if (IS_ERR(bp))
 690                         err = PTR_ERR(bp);
 691                 else
 692                         t->ptrace_bps[nr] = bp;
 693         } else {
 694                 struct perf_event_attr attr = bp->attr;
 695
 696                 attr.bp_addr = addr;
 697                 err = modify_user_hw_breakpoint(bp, &attr);
 698         }
 699
 700         return err;
 701 }
 702
 703 /*
 704  * Handle PTRACE_POKEUSR calls for the debug register area.
 705  */
 706 static int ptrace_set_debugreg(struct task_struct *tsk, int n,
 707                                unsigned long val)
 708 {
 709         struct thread_struct *thread = &tsk->thread;
 710         /* There are no DR4 or DR5 registers */
 711         int rc = -EIO;
 712
 713         if (n < HBP_NUM) {
 714                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
 715         } else if (n == 6) {
 716                 thread->debugreg6 = val;
 717                 rc = 0;
 718         } else if (n == 7) {
 719                 rc = ptrace_write_dr7(tsk, val);
 720                 if (!rc)
 721                         thread->ptrace_dr7 = val;
 722         }
 723         return rc;
 724 }
 725
 726 /*
 727  * These access the current or another (stopped) task's io permission
 728  * bitmap for debugging or core dump.
 729  */
 730 static int ioperm_active(struct task_struct *target,
 731                          const struct user_regset *regset)
 732 {
 733         return target->thread.io_bitmap_max / regset->size;
 734 }
 735
 736 static int ioperm_get(struct task_struct *target,
 737                       const struct user_regset *regset,
 738                       unsigned int pos, unsigned int count,
 739                       void *kbuf, void __user *ubuf)
 740 {
 741         if (!target->thread.io_bitmap_ptr)
 742                 return -ENXIO;
 743
 744         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 745                                    target->thread.io_bitmap_ptr,
 746                                    0, IO_BITMAP_BYTES);
 747 }
 748
 749 /*
 750  * Called by kernel/ptrace.c when detaching..
 751  *
 752  * Make sure the single step bit is not set.
 753  */
 754 void ptrace_disable(struct task_struct *child)
 755 {
 756         user_disable_single_step(child);
 757 #ifdef TIF_SYSCALL_EMU
 758         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 759 #endif
 760 }
 761
 762 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 763 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 764 #endif
 765
 766 long arch_ptrace(struct task_struct *child, long request,
 767                  unsigned long addr, unsigned long data)
 768 {
 769         int ret;
 770         unsigned long __user *datap = (unsigned long __user *)data;
 771
 772         switch (request) {
 773         /* read the word at location addr in the USER area. */
 774         case PTRACE_PEEKUSR: {
 775                 unsigned long tmp;
 776
 777                 ret = -EIO;
 778                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 779                         break;
 780
 781                 tmp = 0;  /* Default return condition */
 782                 if (addr < sizeof(struct user_regs_struct))
 783                         tmp = getreg(child, addr);
 784                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 785                          addr <= offsetof(struct user, u_debugreg[7])) {
 786                         addr -= offsetof(struct user, u_debugreg[0]);
 787                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 788                 }
 789                 ret = put_user(tmp, datap);
 790                 break;
 791         }
 792
 793         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 794                 ret = -EIO;
 795                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 796                         break;
 797
 798                 if (addr < sizeof(struct user_regs_struct))
 799                         ret = putreg(child, addr, data);
 800                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 801                          addr <= offsetof(struct user, u_debugreg[7])) {
 802                         addr -= offsetof(struct user, u_debugreg[0]);
 803                         ret = ptrace_set_debugreg(child,
 804                                                   addr / sizeof(data), data);
 805                 }
 806                 break;
 807
 808         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 809                 return copy_regset_to_user(child,
 810                                            task_user_regset_view(current),
 811                                            REGSET_GENERAL,
 812                                            0, sizeof(struct user_regs_struct),
 813                                            datap);
 814
 815         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 816                 return copy_regset_from_user(child,
 817                                              task_user_regset_view(current),
 818                                              REGSET_GENERAL,
 819                                              0, sizeof(struct user_regs_struct),
 820                                              datap);
 821
 822         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 823                 return copy_regset_to_user(child,
 824                                            task_user_regset_view(current),
 825                                            REGSET_FP,
 826                                            0, sizeof(struct user_i387_struct),
 827                                            datap);
 828
 829         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 830                 return copy_regset_from_user(child,
 831                                              task_user_regset_view(current),
 832                                              REGSET_FP,
 833                                              0, sizeof(struct user_i387_struct),
 834                                              datap);
 835
 836 #ifdef CONFIG_X86_32
 837         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
 838                 return copy_regset_to_user(child, &user_x86_32_view,
 839                                            REGSET_XFP,
 840                                            0, sizeof(struct user_fxsr_struct),
 841                                            datap) ? -EIO : 0;
 842
 843         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
 844                 return copy_regset_from_user(child, &user_x86_32_view,
 845                                              REGSET_XFP,
 846                                              0, sizeof(struct user_fxsr_struct),
 847                                              datap) ? -EIO : 0;
 848 #endif
 849
 850 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 851         case PTRACE_GET_THREAD_AREA:
 852                 if ((int) addr < 0)
 853                         return -EIO;
 854                 ret = do_get_thread_area(child, addr,
 855                                         (struct user_desc __user *)data);
 856                 break;
 857
 858         case PTRACE_SET_THREAD_AREA:
 859                 if ((int) addr < 0)
 860                         return -EIO;
 861                 ret = do_set_thread_area(child, addr,
 862                                         (struct user_desc __user *)data, 0);
 863                 break;
 864 #endif
 865
 866 #ifdef CONFIG_X86_64
 867                 /* normal 64bit interface to access TLS data.
 868                    Works just like arch_prctl, except that the arguments
 869                    are reversed. */
 870         case PTRACE_ARCH_PRCTL:
 871                 ret = do_arch_prctl(child, data, addr);
 872                 break;
 873 #endif
 874
 875         default:
 876                 ret = ptrace_request(child, request, addr, data);
 877                 break;
 878         }
 879
 880         return ret;
 881 }
 882
 883 #ifdef CONFIG_IA32_EMULATION
 884
 885 #include <linux/compat.h>
 886 #include <linux/syscalls.h>
 887 #include <asm/ia32.h>
 888 #include <asm/user32.h>
 889
 890 #define R32(l,q)                                                        \
 891         case offsetof(struct user32, regs.l):                           \
 892                 regs->q = value; break
 893
 894 #define SEG32(rs)                                                       \
 895         case offsetof(struct user32, regs.rs):                          \
 896                 return set_segment_reg(child,                           \
 897                                        offsetof(struct user_regs_struct, rs), \
 898                                        value);                          \
 899                 break
 900
 901 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 902 {
 903         struct pt_regs *regs = task_pt_regs(child);
 904
 905         switch (regno) {
 906
 907         SEG32(cs);
 908         SEG32(ds);
 909         SEG32(es);
 910         SEG32(fs);
 911         SEG32(gs);
 912         SEG32(ss);
 913
 914         R32(ebx, bx);
 915         R32(ecx, cx);
 916         R32(edx, dx);
 917         R32(edi, di);
 918         R32(esi, si);
 919         R32(ebp, bp);
 920         R32(eax, ax);
 921         R32(eip, ip);
 922         R32(esp, sp);
 923
 924         case offsetof(struct user32, regs.orig_eax):
 925                 /*
 926                  * Warning: bizarre corner case fixup here.  A 32-bit
 927                  * debugger setting orig_eax to -1 wants to disable
 928                  * syscall restart.  Make sure that the syscall
 929                  * restart code sign-extends orig_ax.  Also make sure
 930                  * we interpret the -ERESTART* codes correctly if
 931                  * loaded into regs->ax in case the task is not
 932                  * actually still sitting at the exit from a 32-bit
 933                  * syscall with TS_COMPAT still set.
 934                  */
 935                 regs->orig_ax = value;
 936                 if (syscall_get_nr(child, regs) >= 0)
 937                         task_thread_info(child)->status |= TS_I386_REGS_POKED;
 938                 break;
 939
 940         case offsetof(struct user32, regs.eflags):
 941                 return set_flags(child, value);
 942
 943         case offsetof(struct user32, u_debugreg[0]) ...
 944                 offsetof(struct user32, u_debugreg[7]):
 945                 regno -= offsetof(struct user32, u_debugreg[0]);
 946                 return ptrace_set_debugreg(child, regno / 4, value);
 947
 948         default:
 949                 if (regno > sizeof(struct user32) || (regno & 3))
 950                         return -EIO;
 951
 952                 /*
 953                  * Other dummy fields in the virtual user structure
 954                  * are ignored
 955                  */
 956                 break;
 957         }
 958         return 0;
 959 }
 960
 961 #undef R32
 962 #undef SEG32
 963
 964 #define R32(l,q)                                                        \
 965         case offsetof(struct user32, regs.l):                           \
 966                 *val = regs->q; break
 967
 968 #define SEG32(rs)                                                       \
 969         case offsetof(struct user32, regs.rs):                          \
 970                 *val = get_segment_reg(child,                           \
 971                                        offsetof(struct user_regs_struct, rs)); \
 972                 break
 973
 974 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 975 {
 976         struct pt_regs *regs = task_pt_regs(child);
 977
 978         switch (regno) {
 979
 980         SEG32(ds);
 981         SEG32(es);
 982         SEG32(fs);
 983         SEG32(gs);
 984
 985         R32(cs, cs);
 986         R32(ss, ss);
 987         R32(ebx, bx);
 988         R32(ecx, cx);
 989         R32(edx, dx);
 990         R32(edi, di);
 991         R32(esi, si);
 992         R32(ebp, bp);
 993         R32(eax, ax);
 994         R32(orig_eax, orig_ax);
 995         R32(eip, ip);
 996         R32(esp, sp);
 997
 998         case offsetof(struct user32, regs.eflags):
 999                 *val = get_flags(child);
1000                 break;
1001
1002         case offsetof(struct user32, u_debugreg[0]) ...
1003                 offsetof(struct user32, u_debugreg[7]):
1004                 regno -= offsetof(struct user32, u_debugreg[0]);
1005                 *val = ptrace_get_debugreg(child, regno / 4);
1006                 break;
1007
1008         default:
1009                 if (regno > sizeof(struct user32) || (regno & 3))
1010                         return -EIO;
1011
1012                 /*
1013                  * Other dummy fields in the virtual user structure
1014                  * are ignored
1015                  */
1016                 *val = 0;
1017                 break;
1018         }
1019         return 0;
1020 }
1021
1022 #undef R32
1023 #undef SEG32
1024
1025 static int genregs32_get(struct task_struct *target,
1026                          const struct user_regset *regset,
1027                          unsigned int pos, unsigned int count,
1028                          void *kbuf, void __user *ubuf)
1029 {
1030         if (kbuf) {
1031                 compat_ulong_t *k = kbuf;
1032                 while (count >= sizeof(*k)) {
1033                         getreg32(target, pos, k++);
1034                         count -= sizeof(*k);
1035                         pos += sizeof(*k);
1036                 }
1037         } else {
1038                 compat_ulong_t __user *u = ubuf;
1039                 while (count >= sizeof(*u)) {
1040                         compat_ulong_t word;
1041                         getreg32(target, pos, &word);
1042                         if (__put_user(word, u++))
1043                                 return -EFAULT;
1044                         count -= sizeof(*u);
1045                         pos += sizeof(*u);
1046                 }
1047         }
1048
1049         return 0;
1050 }
1051
1052 static int genregs32_set(struct task_struct *target,
1053                          const struct user_regset *regset,
1054                          unsigned int pos, unsigned int count,
1055                          const void *kbuf, const void __user *ubuf)
1056 {
1057         int ret = 0;
1058         if (kbuf) {
1059                 const compat_ulong_t *k = kbuf;
1060                 while (count >= sizeof(*k) && !ret) {
1061                         ret = putreg32(target, pos, *k++);
1062                         count -= sizeof(*k);
1063                         pos += sizeof(*k);
1064                 }
1065         } else {
1066                 const compat_ulong_t __user *u = ubuf;
1067                 while (count >= sizeof(*u) && !ret) {
1068                         compat_ulong_t word;
1069                         ret = __get_user(word, u++);
1070                         if (ret)
1071                                 break;
1072                         ret = putreg32(target, pos, word);
1073                         count -= sizeof(*u);
1074                         pos += sizeof(*u);
1075                 }
1076         }
1077         return ret;
1078 }
1079
1080 static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1081                              compat_ulong_t caddr, compat_ulong_t cdata)
1082 {
1083         unsigned long addr = caddr;
1084         unsigned long data = cdata;
1085         void __user *datap = compat_ptr(data);
1086         int ret;
1087         __u32 val;
1088
1089         switch (request) {
1090         case PTRACE_PEEKUSR:
1091                 ret = getreg32(child, addr, &val);
1092                 if (ret == 0)
1093                         ret = put_user(val, (__u32 __user *)datap);
1094                 break;
1095
1096         case PTRACE_POKEUSR:
1097                 ret = putreg32(child, addr, data);
1098                 break;
1099
1100         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1101                 return copy_regset_to_user(child, &user_x86_32_view,
1102                                            REGSET_GENERAL,
1103                                            0, sizeof(struct user_regs_struct32),
1104                                            datap);
1105
1106         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1107                 return copy_regset_from_user(child, &user_x86_32_view,
1108                                              REGSET_GENERAL, 0,
1109                                              sizeof(struct user_regs_struct32),
1110                                              datap);
1111
1112         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1113                 return copy_regset_to_user(child, &user_x86_32_view,
1114                                            REGSET_FP, 0,
1115                                            sizeof(struct user_i387_ia32_struct),
1116                                            datap);
1117
1118         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1119                 return copy_regset_from_user(
1120                         child, &user_x86_32_view, REGSET_FP,
1121                         0, sizeof(struct user_i387_ia32_struct), datap);
1122
1123         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1124                 return copy_regset_to_user(child, &user_x86_32_view,
1125                                            REGSET_XFP, 0,
1126                                            sizeof(struct user32_fxsr_struct),
1127                                            datap);
1128
1129         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1130                 return copy_regset_from_user(child, &user_x86_32_view,
1131                                              REGSET_XFP, 0,
1132                                              sizeof(struct user32_fxsr_struct),
1133                                              datap);
1134
1135         case PTRACE_GET_THREAD_AREA:
1136         case PTRACE_SET_THREAD_AREA:
1137                 return arch_ptrace(child, request, addr, data);
1138
1139         default:
1140                 return compat_ptrace_request(child, request, addr, data);
1141         }
1142
1143         return ret;
1144 }
1145 #endif /* CONFIG_IA32_EMULATION */
1146
1147 #ifdef CONFIG_X86_X32_ABI
1148 static long x32_arch_ptrace(struct task_struct *child,
1149                             compat_long_t request, compat_ulong_t caddr,
1150                             compat_ulong_t cdata)
1151 {
1152         unsigned long addr = caddr;
1153         unsigned long data = cdata;
1154         void __user *datap = compat_ptr(data);
1155         int ret;
1156
1157         switch (request) {
1158         /* Read 32bits at location addr in the USER area.  Only allow
1159            to return the lower 32bits of segment and debug registers.  */
1160         case PTRACE_PEEKUSR: {
1161                 u32 tmp;
1162
1163                 ret = -EIO;
1164                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1165                     addr < offsetof(struct user_regs_struct, cs))
1166                         break;
1167
1168                 tmp = 0;  /* Default return condition */
1169                 if (addr < sizeof(struct user_regs_struct))
1170                         tmp = getreg(child, addr);
1171                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1172                          addr <= offsetof(struct user, u_debugreg[7])) {
1173                         addr -= offsetof(struct user, u_debugreg[0]);
1174                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1175                 }
1176                 ret = put_user(tmp, (__u32 __user *)datap);
1177                 break;
1178         }
1179
1180         /* Write the word at location addr in the USER area.  Only allow
1181            to update segment and debug registers with the upper 32bits
1182            zero-extended. */
1183         case PTRACE_POKEUSR:
1184                 ret = -EIO;
1185                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1186                     addr < offsetof(struct user_regs_struct, cs))
1187                         break;
1188
1189                 if (addr < sizeof(struct user_regs_struct))
1190                         ret = putreg(child, addr, data);
1191                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1192                          addr <= offsetof(struct user, u_debugreg[7])) {
1193                         addr -= offsetof(struct user, u_debugreg[0]);
1194                         ret = ptrace_set_debugreg(child,
1195                                                   addr / sizeof(data), data);
1196                 }
1197                 break;
1198
1199         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1200                 return copy_regset_to_user(child,
1201                                            task_user_regset_view(current),
1202                                            REGSET_GENERAL,
1203                                            0, sizeof(struct user_regs_struct),
1204                                            datap);
1205
1206         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1207                 return copy_regset_from_user(child,
1208                                              task_user_regset_view(current),
1209                                              REGSET_GENERAL,
1210                                              0, sizeof(struct user_regs_struct),
1211                                              datap);
1212
1213         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1214                 return copy_regset_to_user(child,
1215                                            task_user_regset_view(current),
1216                                            REGSET_FP,
1217                                            0, sizeof(struct user_i387_struct),
1218                                            datap);
1219
1220         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1221                 return copy_regset_from_user(child,
1222                                              task_user_regset_view(current),
1223                                              REGSET_FP,
1224                                              0, sizeof(struct user_i387_struct),
1225                                              datap);
1226
1227         default:
1228                 return compat_ptrace_request(child, request, addr, data);
1229         }
1230
1231         return ret;
1232 }
1233 #endif
1234
1235 #ifdef CONFIG_COMPAT
1236 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1237                         compat_ulong_t caddr, compat_ulong_t cdata)
1238 {
1239 #ifdef CONFIG_X86_X32_ABI
1240         if (!in_ia32_syscall())
1241                 return x32_arch_ptrace(child, request, caddr, cdata);
1242 #endif
1243 #ifdef CONFIG_IA32_EMULATION
1244         return ia32_arch_ptrace(child, request, caddr, cdata);
1245 #else
1246         return 0;
1247 #endif
1248 }
1249 #endif  /* CONFIG_COMPAT */
1250
1251 #ifdef CONFIG_X86_64
1252
1253 static struct user_regset x86_64_regsets[] __read_mostly = {
1254         [REGSET_GENERAL] = {
1255                 .core_note_type = NT_PRSTATUS,
1256                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1257                 .size = sizeof(long), .align = sizeof(long),
1258                 .get = genregs_get, .set = genregs_set
1259         },
1260         [REGSET_FP] = {
1261                 .core_note_type = NT_PRFPREG,
1262                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1263                 .size = sizeof(long), .align = sizeof(long),
1264                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1265         },
1266         [REGSET_XSTATE] = {
1267                 .core_note_type = NT_X86_XSTATE,
1268                 .size = sizeof(u64), .align = sizeof(u64),
1269                 .active = xstateregs_active, .get = xstateregs_get,
1270                 .set = xstateregs_set
1271         },
1272         [REGSET_IOPERM64] = {
1273                 .core_note_type = NT_386_IOPERM,
1274                 .n = IO_BITMAP_LONGS,
1275                 .size = sizeof(long), .align = sizeof(long),
1276                 .active = ioperm_active, .get = ioperm_get
1277         },
1278 };
1279
1280 static const struct user_regset_view user_x86_64_view = {
1281         .name = "x86_64", .e_machine = EM_X86_64,
1282         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1283 };
1284
1285 #else  /* CONFIG_X86_32 */
1286
1287 #define user_regs_struct32      user_regs_struct
1288 #define genregs32_get           genregs_get
1289 #define genregs32_set           genregs_set
1290
1291 #endif  /* CONFIG_X86_64 */
1292
1293 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1294 static struct user_regset x86_32_regsets[] __read_mostly = {
1295         [REGSET_GENERAL] = {
1296                 .core_note_type = NT_PRSTATUS,
1297                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1298                 .size = sizeof(u32), .align = sizeof(u32),
1299                 .get = genregs32_get, .set = genregs32_set
1300         },
1301         [REGSET_FP] = {
1302                 .core_note_type = NT_PRFPREG,
1303                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1304                 .size = sizeof(u32), .align = sizeof(u32),
1305                 .active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1306         },
1307         [REGSET_XFP] = {
1308                 .core_note_type = NT_PRXFPREG,
1309                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1310                 .size = sizeof(u32), .align = sizeof(u32),
1311                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1312         },
1313         [REGSET_XSTATE] = {
1314                 .core_note_type = NT_X86_XSTATE,
1315                 .size = sizeof(u64), .align = sizeof(u64),
1316                 .active = xstateregs_active, .get = xstateregs_get,
1317                 .set = xstateregs_set
1318         },
1319         [REGSET_TLS] = {
1320                 .core_note_type = NT_386_TLS,
1321                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1322                 .size = sizeof(struct user_desc),
1323                 .align = sizeof(struct user_desc),
1324                 .active = regset_tls_active,
1325                 .get = regset_tls_get, .set = regset_tls_set
1326         },
1327         [REGSET_IOPERM32] = {
1328                 .core_note_type = NT_386_IOPERM,
1329                 .n = IO_BITMAP_BYTES / sizeof(u32),
1330                 .size = sizeof(u32), .align = sizeof(u32),
1331                 .active = ioperm_active, .get = ioperm_get
1332         },
1333 };
1334
1335 static const struct user_regset_view user_x86_32_view = {
1336         .name = "i386", .e_machine = EM_386,
1337         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1338 };
1339 #endif
1340
1341 /*
1342  * This represents bytes 464..511 in the memory layout exported through
1343  * the REGSET_XSTATE interface.
1344  */
1345 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1346
1347 void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1348 {
1349 #ifdef CONFIG_X86_64
1350         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1351 #endif
1352 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1353         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1354 #endif
1355         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1356 }
1357
1358 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1359 {
1360 #ifdef CONFIG_IA32_EMULATION
1361         if (test_tsk_thread_flag(task, TIF_IA32))
1362 #endif
1363 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1364                 return &user_x86_32_view;
1365 #endif
1366 #ifdef CONFIG_X86_64
1367         return &user_x86_64_view;
1368 #endif
1369 }
1370
1371 static void fill_sigtrap_info(struct task_struct *tsk,
1372                                 struct pt_regs *regs,
1373                                 int error_code, int si_code,
1374                                 struct siginfo *info)
1375 {
1376         tsk->thread.trap_nr = X86_TRAP_DB;
1377         tsk->thread.error_code = error_code;
1378
1379         memset(info, 0, sizeof(*info));
1380         info->si_signo = SIGTRAP;
1381         info->si_code = si_code;
1382         info->si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
1383 }
1384
1385 void user_single_step_siginfo(struct task_struct *tsk,
1386                                 struct pt_regs *regs,
1387                                 struct siginfo *info)
1388 {
1389         fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1390 }
1391
1392 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1393                                          int error_code, int si_code)
1394 {
1395         struct siginfo info;
1396
1397         fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1398         /* Send us the fake SIGTRAP */
1399         force_sig_info(SIGTRAP, &info, tsk);
1400 }