linux/arch/x86/kernel/ptrace.c
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   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/sched/task_stack.h>
  10#include <linux/mm.h>
  11#include <linux/smp.h>
  12#include <linux/errno.h>
  13#include <linux/slab.h>
  14#include <linux/ptrace.h>
  15#include <linux/tracehook.h>
  16#include <linux/user.h>
  17#include <linux/elf.h>
  18#include <linux/security.h>
  19#include <linux/audit.h>
  20#include <linux/seccomp.h>
  21#include <linux/signal.h>
  22#include <linux/perf_event.h>
  23#include <linux/hw_breakpoint.h>
  24#include <linux/rcupdate.h>
  25#include <linux/export.h>
  26#include <linux/context_tracking.h>
  27
  28#include <linux/uaccess.h>
  29#include <asm/pgtable.h>
  30#include <asm/processor.h>
  31#include <asm/fpu/internal.h>
  32#include <asm/fpu/signal.h>
  33#include <asm/fpu/regset.h>
  34#include <asm/debugreg.h>
  35#include <asm/ldt.h>
  36#include <asm/desc.h>
  37#include <asm/prctl.h>
  38#include <asm/proto.h>
  39#include <asm/hw_breakpoint.h>
  40#include <asm/traps.h>
  41#include <asm/syscall.h>
  42
  43#include "tls.h"
  44
  45enum x86_regset {
  46        REGSET_GENERAL,
  47        REGSET_FP,
  48        REGSET_XFP,
  49        REGSET_IOPERM64 = REGSET_XFP,
  50        REGSET_XSTATE,
  51        REGSET_TLS,
  52        REGSET_IOPERM32,
  53};
  54
  55struct pt_regs_offset {
  56        const char *name;
  57        int offset;
  58};
  59
  60#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  61#define REG_OFFSET_END {.name = NULL, .offset = 0}
  62
  63static const struct pt_regs_offset regoffset_table[] = {
  64#ifdef CONFIG_X86_64
  65        REG_OFFSET_NAME(r15),
  66        REG_OFFSET_NAME(r14),
  67        REG_OFFSET_NAME(r13),
  68        REG_OFFSET_NAME(r12),
  69        REG_OFFSET_NAME(r11),
  70        REG_OFFSET_NAME(r10),
  71        REG_OFFSET_NAME(r9),
  72        REG_OFFSET_NAME(r8),
  73#endif
  74        REG_OFFSET_NAME(bx),
  75        REG_OFFSET_NAME(cx),
  76        REG_OFFSET_NAME(dx),
  77        REG_OFFSET_NAME(si),
  78        REG_OFFSET_NAME(di),
  79        REG_OFFSET_NAME(bp),
  80        REG_OFFSET_NAME(ax),
  81#ifdef CONFIG_X86_32
  82        REG_OFFSET_NAME(ds),
  83        REG_OFFSET_NAME(es),
  84        REG_OFFSET_NAME(fs),
  85        REG_OFFSET_NAME(gs),
  86#endif
  87        REG_OFFSET_NAME(orig_ax),
  88        REG_OFFSET_NAME(ip),
  89        REG_OFFSET_NAME(cs),
  90        REG_OFFSET_NAME(flags),
  91        REG_OFFSET_NAME(sp),
  92        REG_OFFSET_NAME(ss),
  93        REG_OFFSET_END,
  94};
  95
  96/**
  97 * regs_query_register_offset() - query register offset from its name
  98 * @name:       the name of a register
  99 *
 100 * regs_query_register_offset() returns the offset of a register in struct
 101 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 102 */
 103int regs_query_register_offset(const char *name)
 104{
 105        const struct pt_regs_offset *roff;
 106        for (roff = regoffset_table; roff->name != NULL; roff++)
 107                if (!strcmp(roff->name, name))
 108                        return roff->offset;
 109        return -EINVAL;
 110}
 111
 112/**
 113 * regs_query_register_name() - query register name from its offset
 114 * @offset:     the offset of a register in struct pt_regs.
 115 *
 116 * regs_query_register_name() returns the name of a register from its
 117 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 118 */
 119const char *regs_query_register_name(unsigned int offset)
 120{
 121        const struct pt_regs_offset *roff;
 122        for (roff = regoffset_table; roff->name != NULL; roff++)
 123                if (roff->offset == offset)
 124                        return roff->name;
 125        return NULL;
 126}
 127
 128/*
 129 * does not yet catch signals sent when the child dies.
 130 * in exit.c or in signal.c.
 131 */
 132
 133/*
 134 * Determines which flags the user has access to [1 = access, 0 = no access].
 135 */
 136#define FLAG_MASK_32            ((unsigned long)                        \
 137                                 (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
 138                                  X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
 139                                  X86_EFLAGS_SF | X86_EFLAGS_TF |       \
 140                                  X86_EFLAGS_DF | X86_EFLAGS_OF |       \
 141                                  X86_EFLAGS_RF | X86_EFLAGS_AC))
 142
 143/*
 144 * Determines whether a value may be installed in a segment register.
 145 */
 146static inline bool invalid_selector(u16 value)
 147{
 148        return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
 149}
 150
 151#ifdef CONFIG_X86_32
 152
 153#define FLAG_MASK               FLAG_MASK_32
 154
 155/*
 156 * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
 157 * when it traps.  The previous stack will be directly underneath the saved
 158 * registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
 159 *
 160 * Now, if the stack is empty, '&regs->sp' is out of range. In this
 161 * case we try to take the previous stack. To always return a non-null
 162 * stack pointer we fall back to regs as stack if no previous stack
 163 * exists.
 164 *
 165 * This is valid only for kernel mode traps.
 166 */
 167unsigned long kernel_stack_pointer(struct pt_regs *regs)
 168{
 169        unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
 170        unsigned long sp = (unsigned long)&regs->sp;
 171        u32 *prev_esp;
 172
 173        if (context == (sp & ~(THREAD_SIZE - 1)))
 174                return sp;
 175
 176        prev_esp = (u32 *)(context);
 177        if (*prev_esp)
 178                return (unsigned long)*prev_esp;
 179
 180        return (unsigned long)regs;
 181}
 182EXPORT_SYMBOL_GPL(kernel_stack_pointer);
 183
 184static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 185{
 186        BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 187        return &regs->bx + (regno >> 2);
 188}
 189
 190static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 191{
 192        /*
 193         * Returning the value truncates it to 16 bits.
 194         */
 195        unsigned int retval;
 196        if (offset != offsetof(struct user_regs_struct, gs))
 197                retval = *pt_regs_access(task_pt_regs(task), offset);
 198        else {
 199                if (task == current)
 200                        retval = get_user_gs(task_pt_regs(task));
 201                else
 202                        retval = task_user_gs(task);
 203        }
 204        return retval;
 205}
 206
 207static int set_segment_reg(struct task_struct *task,
 208                           unsigned long offset, u16 value)
 209{
 210        /*
 211         * The value argument was already truncated to 16 bits.
 212         */
 213        if (invalid_selector(value))
 214                return -EIO;
 215
 216        /*
 217         * For %cs and %ss we cannot permit a null selector.
 218         * We can permit a bogus selector as long as it has USER_RPL.
 219         * Null selectors are fine for other segment registers, but
 220         * we will never get back to user mode with invalid %cs or %ss
 221         * and will take the trap in iret instead.  Much code relies
 222         * on user_mode() to distinguish a user trap frame (which can
 223         * safely use invalid selectors) from a kernel trap frame.
 224         */
 225        switch (offset) {
 226        case offsetof(struct user_regs_struct, cs):
 227        case offsetof(struct user_regs_struct, ss):
 228                if (unlikely(value == 0))
 229                        return -EIO;
 230
 231        default:
 232                *pt_regs_access(task_pt_regs(task), offset) = value;
 233                break;
 234
 235        case offsetof(struct user_regs_struct, gs):
 236                if (task == current)
 237                        set_user_gs(task_pt_regs(task), value);
 238                else
 239                        task_user_gs(task) = value;
 240        }
 241
 242        return 0;
 243}
 244
 245#else  /* CONFIG_X86_64 */
 246
 247#define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
 248
 249static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 250{
 251        BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 252        return &regs->r15 + (offset / sizeof(regs->r15));
 253}
 254
 255static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 256{
 257        /*
 258         * Returning the value truncates it to 16 bits.
 259         */
 260        unsigned int seg;
 261
 262        switch (offset) {
 263        case offsetof(struct user_regs_struct, fs):
 264                if (task == current) {
 265                        /* Older gas can't assemble movq %?s,%r?? */
 266                        asm("movl %%fs,%0" : "=r" (seg));
 267                        return seg;
 268                }
 269                return task->thread.fsindex;
 270        case offsetof(struct user_regs_struct, gs):
 271                if (task == current) {
 272                        asm("movl %%gs,%0" : "=r" (seg));
 273                        return seg;
 274                }
 275                return task->thread.gsindex;
 276        case offsetof(struct user_regs_struct, ds):
 277                if (task == current) {
 278                        asm("movl %%ds,%0" : "=r" (seg));
 279                        return seg;
 280                }
 281                return task->thread.ds;
 282        case offsetof(struct user_regs_struct, es):
 283                if (task == current) {
 284                        asm("movl %%es,%0" : "=r" (seg));
 285                        return seg;
 286                }
 287                return task->thread.es;
 288
 289        case offsetof(struct user_regs_struct, cs):
 290        case offsetof(struct user_regs_struct, ss):
 291                break;
 292        }
 293        return *pt_regs_access(task_pt_regs(task), offset);
 294}
 295
 296static int set_segment_reg(struct task_struct *task,
 297                           unsigned long offset, u16 value)
 298{
 299        /*
 300         * The value argument was already truncated to 16 bits.
 301         */
 302        if (invalid_selector(value))
 303                return -EIO;
 304
 305        switch (offset) {
 306        case offsetof(struct user_regs_struct,fs):
 307                task->thread.fsindex = value;
 308                if (task == current)
 309                        loadsegment(fs, task->thread.fsindex);
 310                break;
 311        case offsetof(struct user_regs_struct,gs):
 312                task->thread.gsindex = value;
 313                if (task == current)
 314                        load_gs_index(task->thread.gsindex);
 315                break;
 316        case offsetof(struct user_regs_struct,ds):
 317                task->thread.ds = value;
 318                if (task == current)
 319                        loadsegment(ds, task->thread.ds);
 320                break;
 321        case offsetof(struct user_regs_struct,es):
 322                task->thread.es = value;
 323                if (task == current)
 324                        loadsegment(es, task->thread.es);
 325                break;
 326
 327                /*
 328                 * Can't actually change these in 64-bit mode.
 329                 */
 330        case offsetof(struct user_regs_struct,cs):
 331                if (unlikely(value == 0))
 332                        return -EIO;
 333                task_pt_regs(task)->cs = value;
 334                break;
 335        case offsetof(struct user_regs_struct,ss):
 336                if (unlikely(value == 0))
 337                        return -EIO;
 338                task_pt_regs(task)->ss = value;
 339                break;
 340        }
 341
 342        return 0;
 343}
 344
 345#endif  /* CONFIG_X86_32 */
 346
 347static unsigned long get_flags(struct task_struct *task)
 348{
 349        unsigned long retval = task_pt_regs(task)->flags;
 350
 351        /*
 352         * If the debugger set TF, hide it from the readout.
 353         */
 354        if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 355                retval &= ~X86_EFLAGS_TF;
 356
 357        return retval;
 358}
 359
 360static int set_flags(struct task_struct *task, unsigned long value)
 361{
 362        struct pt_regs *regs = task_pt_regs(task);
 363
 364        /*
 365         * If the user value contains TF, mark that
 366         * it was not "us" (the debugger) that set it.
 367         * If not, make sure it stays set if we had.
 368         */
 369        if (value & X86_EFLAGS_TF)
 370                clear_tsk_thread_flag(task, TIF_FORCED_TF);
 371        else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 372                value |= X86_EFLAGS_TF;
 373
 374        regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 375
 376        return 0;
 377}
 378
 379static int putreg(struct task_struct *child,
 380                  unsigned long offset, unsigned long value)
 381{
 382        switch (offset) {
 383        case offsetof(struct user_regs_struct, cs):
 384        case offsetof(struct user_regs_struct, ds):
 385        case offsetof(struct user_regs_struct, es):
 386        case offsetof(struct user_regs_struct, fs):
 387        case offsetof(struct user_regs_struct, gs):
 388        case offsetof(struct user_regs_struct, ss):
 389                return set_segment_reg(child, offset, value);
 390
 391        case offsetof(struct user_regs_struct, flags):
 392                return set_flags(child, value);
 393
 394#ifdef CONFIG_X86_64
 395        case offsetof(struct user_regs_struct,fs_base):
 396                if (value >= TASK_SIZE_MAX)
 397                        return -EIO;
 398                /*
 399                 * When changing the segment base, use do_arch_prctl_64
 400                 * to set either thread.fs or thread.fsindex and the
 401                 * corresponding GDT slot.
 402                 */
 403                if (child->thread.fsbase != value)
 404                        return do_arch_prctl_64(child, ARCH_SET_FS, value);
 405                return 0;
 406        case offsetof(struct user_regs_struct,gs_base):
 407                /*
 408                 * Exactly the same here as the %fs handling above.
 409                 */
 410                if (value >= TASK_SIZE_MAX)
 411                        return -EIO;
 412                if (child->thread.gsbase != value)
 413                        return do_arch_prctl_64(child, ARCH_SET_GS, value);
 414                return 0;
 415#endif
 416        }
 417
 418        *pt_regs_access(task_pt_regs(child), offset) = value;
 419        return 0;
 420}
 421
 422static unsigned long getreg(struct task_struct *task, unsigned long offset)
 423{
 424        switch (offset) {
 425        case offsetof(struct user_regs_struct, cs):
 426        case offsetof(struct user_regs_struct, ds):
 427        case offsetof(struct user_regs_struct, es):
 428        case offsetof(struct user_regs_struct, fs):
 429        case offsetof(struct user_regs_struct, gs):
 430        case offsetof(struct user_regs_struct, ss):
 431                return get_segment_reg(task, offset);
 432
 433        case offsetof(struct user_regs_struct, flags):
 434                return get_flags(task);
 435
 436#ifdef CONFIG_X86_64
 437        case offsetof(struct user_regs_struct, fs_base): {
 438                /*
 439                 * XXX: This will not behave as expected if called on
 440                 * current or if fsindex != 0.
 441                 */
 442                return task->thread.fsbase;
 443        }
 444        case offsetof(struct user_regs_struct, gs_base): {
 445                /*
 446                 * XXX: This will not behave as expected if called on
 447                 * current or if fsindex != 0.
 448                 */
 449                return task->thread.gsbase;
 450        }
 451#endif
 452        }
 453
 454        return *pt_regs_access(task_pt_regs(task), offset);
 455}
 456
 457static int genregs_get(struct task_struct *target,
 458                       const struct user_regset *regset,
 459                       unsigned int pos, unsigned int count,
 460                       void *kbuf, void __user *ubuf)
 461{
 462        if (kbuf) {
 463                unsigned long *k = kbuf;
 464                while (count >= sizeof(*k)) {
 465                        *k++ = getreg(target, pos);
 466                        count -= sizeof(*k);
 467                        pos += sizeof(*k);
 468                }
 469        } else {
 470                unsigned long __user *u = ubuf;
 471                while (count >= sizeof(*u)) {
 472                        if (__put_user(getreg(target, pos), u++))
 473                                return -EFAULT;
 474                        count -= sizeof(*u);
 475                        pos += sizeof(*u);
 476                }
 477        }
 478
 479        return 0;
 480}
 481
 482static int genregs_set(struct task_struct *target,
 483                       const struct user_regset *regset,
 484                       unsigned int pos, unsigned int count,
 485                       const void *kbuf, const void __user *ubuf)
 486{
 487        int ret = 0;
 488        if (kbuf) {
 489                const unsigned long *k = kbuf;
 490                while (count >= sizeof(*k) && !ret) {
 491                        ret = putreg(target, pos, *k++);
 492                        count -= sizeof(*k);
 493                        pos += sizeof(*k);
 494                }
 495        } else {
 496                const unsigned long  __user *u = ubuf;
 497                while (count >= sizeof(*u) && !ret) {
 498                        unsigned long word;
 499                        ret = __get_user(word, u++);
 500                        if (ret)
 501                                break;
 502                        ret = putreg(target, pos, word);
 503                        count -= sizeof(*u);
 504                        pos += sizeof(*u);
 505                }
 506        }
 507        return ret;
 508}
 509
 510static void ptrace_triggered(struct perf_event *bp,
 511                             struct perf_sample_data *data,
 512                             struct pt_regs *regs)
 513{
 514        int i;
 515        struct thread_struct *thread = &(current->thread);
 516
 517        /*
 518         * Store in the virtual DR6 register the fact that the breakpoint
 519         * was hit so the thread's debugger will see it.
 520         */
 521        for (i = 0; i < HBP_NUM; i++) {
 522                if (thread->ptrace_bps[i] == bp)
 523                        break;
 524        }
 525
 526        thread->debugreg6 |= (DR_TRAP0 << i);
 527}
 528
 529/*
 530 * Walk through every ptrace breakpoints for this thread and
 531 * build the dr7 value on top of their attributes.
 532 *
 533 */
 534static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 535{
 536        int i;
 537        int dr7 = 0;
 538        struct arch_hw_breakpoint *info;
 539
 540        for (i = 0; i < HBP_NUM; i++) {
 541                if (bp[i] && !bp[i]->attr.disabled) {
 542                        info = counter_arch_bp(bp[i]);
 543                        dr7 |= encode_dr7(i, info->len, info->type);
 544                }
 545        }
 546
 547        return dr7;
 548}
 549
 550static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
 551                                        int len, int type, bool disabled)
 552{
 553        int err, bp_len, bp_type;
 554
 555        err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
 556        if (!err) {
 557                attr->bp_len = bp_len;
 558                attr->bp_type = bp_type;
 559                attr->disabled = disabled;
 560        }
 561
 562        return err;
 563}
 564
 565static struct perf_event *
 566ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
 567                                unsigned long addr, bool disabled)
 568{
 569        struct perf_event_attr attr;
 570        int err;
 571
 572        ptrace_breakpoint_init(&attr);
 573        attr.bp_addr = addr;
 574
 575        err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 576        if (err)
 577                return ERR_PTR(err);
 578
 579        return register_user_hw_breakpoint(&attr, ptrace_triggered,
 580                                                 NULL, tsk);
 581}
 582
 583static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 584                                        int disabled)
 585{
 586        struct perf_event_attr attr = bp->attr;
 587        int err;
 588
 589        err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 590        if (err)
 591                return err;
 592
 593        return modify_user_hw_breakpoint(bp, &attr);
 594}
 595
 596/*
 597 * Handle ptrace writes to debug register 7.
 598 */
 599static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 600{
 601        struct thread_struct *thread = &tsk->thread;
 602        unsigned long old_dr7;
 603        bool second_pass = false;
 604        int i, rc, ret = 0;
 605
 606        data &= ~DR_CONTROL_RESERVED;
 607        old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 608
 609restore:
 610        rc = 0;
 611        for (i = 0; i < HBP_NUM; i++) {
 612                unsigned len, type;
 613                bool disabled = !decode_dr7(data, i, &len, &type);
 614                struct perf_event *bp = thread->ptrace_bps[i];
 615
 616                if (!bp) {
 617                        if (disabled)
 618                                continue;
 619
 620                        bp = ptrace_register_breakpoint(tsk,
 621                                        len, type, 0, disabled);
 622                        if (IS_ERR(bp)) {
 623                                rc = PTR_ERR(bp);
 624                                break;
 625                        }
 626
 627                        thread->ptrace_bps[i] = bp;
 628                        continue;
 629                }
 630
 631                rc = ptrace_modify_breakpoint(bp, len, type, disabled);
 632                if (rc)
 633                        break;
 634        }
 635
 636        /* Restore if the first pass failed, second_pass shouldn't fail. */
 637        if (rc && !WARN_ON(second_pass)) {
 638                ret = rc;
 639                data = old_dr7;
 640                second_pass = true;
 641                goto restore;
 642        }
 643
 644        return ret;
 645}
 646
 647/*
 648 * Handle PTRACE_PEEKUSR calls for the debug register area.
 649 */
 650static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 651{
 652        struct thread_struct *thread = &tsk->thread;
 653        unsigned long val = 0;
 654
 655        if (n < HBP_NUM) {
 656                struct perf_event *bp = thread->ptrace_bps[n];
 657
 658                if (bp)
 659                        val = bp->hw.info.address;
 660        } else if (n == 6) {
 661                val = thread->debugreg6;
 662        } else if (n == 7) {
 663                val = thread->ptrace_dr7;
 664        }
 665        return val;
 666}
 667
 668static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 669                                      unsigned long addr)
 670{
 671        struct thread_struct *t = &tsk->thread;
 672        struct perf_event *bp = t->ptrace_bps[nr];
 673        int err = 0;
 674
 675        if (!bp) {
 676                /*
 677                 * Put stub len and type to create an inactive but correct bp.
 678                 *
 679                 * CHECKME: the previous code returned -EIO if the addr wasn't
 680                 * a valid task virtual addr. The new one will return -EINVAL in
 681                 *  this case.
 682                 * -EINVAL may be what we want for in-kernel breakpoints users,
 683                 * but -EIO looks better for ptrace, since we refuse a register
 684                 * writing for the user. And anyway this is the previous
 685                 * behaviour.
 686                 */
 687                bp = ptrace_register_breakpoint(tsk,
 688                                X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
 689                                addr, true);
 690                if (IS_ERR(bp))
 691                        err = PTR_ERR(bp);
 692                else
 693                        t->ptrace_bps[nr] = bp;
 694        } else {
 695                struct perf_event_attr attr = bp->attr;
 696
 697                attr.bp_addr = addr;
 698                err = modify_user_hw_breakpoint(bp, &attr);
 699        }
 700
 701        return err;
 702}
 703
 704/*
 705 * Handle PTRACE_POKEUSR calls for the debug register area.
 706 */
 707static int ptrace_set_debugreg(struct task_struct *tsk, int n,
 708                               unsigned long val)
 709{
 710        struct thread_struct *thread = &tsk->thread;
 711        /* There are no DR4 or DR5 registers */
 712        int rc = -EIO;
 713
 714        if (n < HBP_NUM) {
 715                rc = ptrace_set_breakpoint_addr(tsk, n, val);
 716        } else if (n == 6) {
 717                thread->debugreg6 = val;
 718                rc = 0;
 719        } else if (n == 7) {
 720                rc = ptrace_write_dr7(tsk, val);
 721                if (!rc)
 722                        thread->ptrace_dr7 = val;
 723        }
 724        return rc;
 725}
 726
 727/*
 728 * These access the current or another (stopped) task's io permission
 729 * bitmap for debugging or core dump.
 730 */
 731static int ioperm_active(struct task_struct *target,
 732                         const struct user_regset *regset)
 733{
 734        return target->thread.io_bitmap_max / regset->size;
 735}
 736
 737static int ioperm_get(struct task_struct *target,
 738                      const struct user_regset *regset,
 739                      unsigned int pos, unsigned int count,
 740                      void *kbuf, void __user *ubuf)
 741{
 742        if (!target->thread.io_bitmap_ptr)
 743                return -ENXIO;
 744
 745        return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 746                                   target->thread.io_bitmap_ptr,
 747                                   0, IO_BITMAP_BYTES);
 748}
 749
 750/*
 751 * Called by kernel/ptrace.c when detaching..
 752 *
 753 * Make sure the single step bit is not set.
 754 */
 755void ptrace_disable(struct task_struct *child)
 756{
 757        user_disable_single_step(child);
 758#ifdef TIF_SYSCALL_EMU
 759        clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 760#endif
 761}
 762
 763#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 764static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 765#endif
 766
 767long arch_ptrace(struct task_struct *child, long request,
 768                 unsigned long addr, unsigned long data)
 769{
 770        int ret;
 771        unsigned long __user *datap = (unsigned long __user *)data;
 772
 773        switch (request) {
 774        /* read the word at location addr in the USER area. */
 775        case PTRACE_PEEKUSR: {
 776                unsigned long tmp;
 777
 778                ret = -EIO;
 779                if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 780                        break;
 781
 782                tmp = 0;  /* Default return condition */
 783                if (addr < sizeof(struct user_regs_struct))
 784                        tmp = getreg(child, addr);
 785                else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 786                         addr <= offsetof(struct user, u_debugreg[7])) {
 787                        addr -= offsetof(struct user, u_debugreg[0]);
 788                        tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 789                }
 790                ret = put_user(tmp, datap);
 791                break;
 792        }
 793
 794        case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 795                ret = -EIO;
 796                if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 797                        break;
 798
 799                if (addr < sizeof(struct user_regs_struct))
 800                        ret = putreg(child, addr, data);
 801                else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 802                         addr <= offsetof(struct user, u_debugreg[7])) {
 803                        addr -= offsetof(struct user, u_debugreg[0]);
 804                        ret = ptrace_set_debugreg(child,
 805                                                  addr / sizeof(data), data);
 806                }
 807                break;
 808
 809        case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 810                return copy_regset_to_user(child,
 811                                           task_user_regset_view(current),
 812                                           REGSET_GENERAL,
 813                                           0, sizeof(struct user_regs_struct),
 814                                           datap);
 815
 816        case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 817                return copy_regset_from_user(child,
 818                                             task_user_regset_view(current),
 819                                             REGSET_GENERAL,
 820                                             0, sizeof(struct user_regs_struct),
 821                                             datap);
 822
 823        case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 824                return copy_regset_to_user(child,
 825                                           task_user_regset_view(current),
 826                                           REGSET_FP,
 827                                           0, sizeof(struct user_i387_struct),
 828                                           datap);
 829
 830        case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 831                return copy_regset_from_user(child,
 832                                             task_user_regset_view(current),
 833                                             REGSET_FP,
 834                                             0, sizeof(struct user_i387_struct),
 835                                             datap);
 836
 837#ifdef CONFIG_X86_32
 838        case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
 839                return copy_regset_to_user(child, &user_x86_32_view,
 840                                           REGSET_XFP,
 841                                           0, sizeof(struct user_fxsr_struct),
 842                                           datap) ? -EIO : 0;
 843
 844        case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
 845                return copy_regset_from_user(child, &user_x86_32_view,
 846                                             REGSET_XFP,
 847                                             0, sizeof(struct user_fxsr_struct),
 848                                             datap) ? -EIO : 0;
 849#endif
 850
 851#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 852        case PTRACE_GET_THREAD_AREA:
 853                if ((int) addr < 0)
 854                        return -EIO;
 855                ret = do_get_thread_area(child, addr,
 856                                        (struct user_desc __user *)data);
 857                break;
 858
 859        case PTRACE_SET_THREAD_AREA:
 860                if ((int) addr < 0)
 861                        return -EIO;
 862                ret = do_set_thread_area(child, addr,
 863                                        (struct user_desc __user *)data, 0);
 864                break;
 865#endif
 866
 867#ifdef CONFIG_X86_64
 868                /* normal 64bit interface to access TLS data.
 869                   Works just like arch_prctl, except that the arguments
 870                   are reversed. */
 871        case PTRACE_ARCH_PRCTL:
 872                ret = do_arch_prctl_64(child, data, addr);
 873                break;
 874#endif
 875
 876        default:
 877                ret = ptrace_request(child, request, addr, data);
 878                break;
 879        }
 880
 881        return ret;
 882}
 883
 884#ifdef CONFIG_IA32_EMULATION
 885
 886#include <linux/compat.h>
 887#include <linux/syscalls.h>
 888#include <asm/ia32.h>
 889#include <asm/user32.h>
 890
 891#define R32(l,q)                                                        \
 892        case offsetof(struct user32, regs.l):                           \
 893                regs->q = value; break
 894
 895#define SEG32(rs)                                                       \
 896        case offsetof(struct user32, regs.rs):                          \
 897                return set_segment_reg(child,                           \
 898                                       offsetof(struct user_regs_struct, rs), \
 899                                       value);                          \
 900                break
 901
 902static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 903{
 904        struct pt_regs *regs = task_pt_regs(child);
 905
 906        switch (regno) {
 907
 908        SEG32(cs);
 909        SEG32(ds);
 910        SEG32(es);
 911        SEG32(fs);
 912        SEG32(gs);
 913        SEG32(ss);
 914
 915        R32(ebx, bx);
 916        R32(ecx, cx);
 917        R32(edx, dx);
 918        R32(edi, di);
 919        R32(esi, si);
 920        R32(ebp, bp);
 921        R32(eax, ax);
 922        R32(eip, ip);
 923        R32(esp, sp);
 924
 925        case offsetof(struct user32, regs.orig_eax):
 926                /*
 927                 * Warning: bizarre corner case fixup here.  A 32-bit
 928                 * debugger setting orig_eax to -1 wants to disable
 929                 * syscall restart.  Make sure that the syscall
 930                 * restart code sign-extends orig_ax.  Also make sure
 931                 * we interpret the -ERESTART* codes correctly if
 932                 * loaded into regs->ax in case the task is not
 933                 * actually still sitting at the exit from a 32-bit
 934                 * syscall with TS_COMPAT still set.
 935                 */
 936                regs->orig_ax = value;
 937                if (syscall_get_nr(child, regs) >= 0)
 938                        child->thread.status |= TS_I386_REGS_POKED;
 939                break;
 940
 941        case offsetof(struct user32, regs.eflags):
 942                return set_flags(child, value);
 943
 944        case offsetof(struct user32, u_debugreg[0]) ...
 945                offsetof(struct user32, u_debugreg[7]):
 946                regno -= offsetof(struct user32, u_debugreg[0]);
 947                return ptrace_set_debugreg(child, regno / 4, value);
 948
 949        default:
 950                if (regno > sizeof(struct user32) || (regno & 3))
 951                        return -EIO;
 952
 953                /*
 954                 * Other dummy fields in the virtual user structure
 955                 * are ignored
 956                 */
 957                break;
 958        }
 959        return 0;
 960}
 961
 962#undef R32
 963#undef SEG32
 964
 965#define R32(l,q)                                                        \
 966        case offsetof(struct user32, regs.l):                           \
 967                *val = regs->q; break
 968
 969#define SEG32(rs)                                                       \
 970        case offsetof(struct user32, regs.rs):                          \
 971                *val = get_segment_reg(child,                           \
 972                                       offsetof(struct user_regs_struct, rs)); \
 973                break
 974
 975static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 976{
 977        struct pt_regs *regs = task_pt_regs(child);
 978
 979        switch (regno) {
 980
 981        SEG32(ds);
 982        SEG32(es);
 983        SEG32(fs);
 984        SEG32(gs);
 985
 986        R32(cs, cs);
 987        R32(ss, ss);
 988        R32(ebx, bx);
 989        R32(ecx, cx);
 990        R32(edx, dx);
 991        R32(edi, di);
 992        R32(esi, si);
 993        R32(ebp, bp);
 994        R32(eax, ax);
 995        R32(orig_eax, orig_ax);
 996        R32(eip, ip);
 997        R32(esp, sp);
 998
 999        case offsetof(struct user32, regs.eflags):
1000                *val = get_flags(child);
1001                break;
1002
1003        case offsetof(struct user32, u_debugreg[0]) ...
1004                offsetof(struct user32, u_debugreg[7]):
1005                regno -= offsetof(struct user32, u_debugreg[0]);
1006                *val = ptrace_get_debugreg(child, regno / 4);
1007                break;
1008
1009        default:
1010                if (regno > sizeof(struct user32) || (regno & 3))
1011                        return -EIO;
1012
1013                /*
1014                 * Other dummy fields in the virtual user structure
1015                 * are ignored
1016                 */
1017                *val = 0;
1018                break;
1019        }
1020        return 0;
1021}
1022
1023#undef R32
1024#undef SEG32
1025
1026static int genregs32_get(struct task_struct *target,
1027                         const struct user_regset *regset,
1028                         unsigned int pos, unsigned int count,
1029                         void *kbuf, void __user *ubuf)
1030{
1031        if (kbuf) {
1032                compat_ulong_t *k = kbuf;
1033                while (count >= sizeof(*k)) {
1034                        getreg32(target, pos, k++);
1035                        count -= sizeof(*k);
1036                        pos += sizeof(*k);
1037                }
1038        } else {
1039                compat_ulong_t __user *u = ubuf;
1040                while (count >= sizeof(*u)) {
1041                        compat_ulong_t word;
1042                        getreg32(target, pos, &word);
1043                        if (__put_user(word, u++))
1044                                return -EFAULT;
1045                        count -= sizeof(*u);
1046                        pos += sizeof(*u);
1047                }
1048        }
1049
1050        return 0;
1051}
1052
1053static int genregs32_set(struct task_struct *target,
1054                         const struct user_regset *regset,
1055                         unsigned int pos, unsigned int count,
1056                         const void *kbuf, const void __user *ubuf)
1057{
1058        int ret = 0;
1059        if (kbuf) {
1060                const compat_ulong_t *k = kbuf;
1061                while (count >= sizeof(*k) && !ret) {
1062                        ret = putreg32(target, pos, *k++);
1063                        count -= sizeof(*k);
1064                        pos += sizeof(*k);
1065                }
1066        } else {
1067                const compat_ulong_t __user *u = ubuf;
1068                while (count >= sizeof(*u) && !ret) {
1069                        compat_ulong_t word;
1070                        ret = __get_user(word, u++);
1071                        if (ret)
1072                                break;
1073                        ret = putreg32(target, pos, word);
1074                        count -= sizeof(*u);
1075                        pos += sizeof(*u);
1076                }
1077        }
1078        return ret;
1079}
1080
1081static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1082                             compat_ulong_t caddr, compat_ulong_t cdata)
1083{
1084        unsigned long addr = caddr;
1085        unsigned long data = cdata;
1086        void __user *datap = compat_ptr(data);
1087        int ret;
1088        __u32 val;
1089
1090        switch (request) {
1091        case PTRACE_PEEKUSR:
1092                ret = getreg32(child, addr, &val);
1093                if (ret == 0)
1094                        ret = put_user(val, (__u32 __user *)datap);
1095                break;
1096
1097        case PTRACE_POKEUSR:
1098                ret = putreg32(child, addr, data);
1099                break;
1100
1101        case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1102                return copy_regset_to_user(child, &user_x86_32_view,
1103                                           REGSET_GENERAL,
1104                                           0, sizeof(struct user_regs_struct32),
1105                                           datap);
1106
1107        case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1108                return copy_regset_from_user(child, &user_x86_32_view,
1109                                             REGSET_GENERAL, 0,
1110                                             sizeof(struct user_regs_struct32),
1111                                             datap);
1112
1113        case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1114                return copy_regset_to_user(child, &user_x86_32_view,
1115                                           REGSET_FP, 0,
1116                                           sizeof(struct user_i387_ia32_struct),
1117                                           datap);
1118
1119        case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1120                return copy_regset_from_user(
1121                        child, &user_x86_32_view, REGSET_FP,
1122                        0, sizeof(struct user_i387_ia32_struct), datap);
1123
1124        case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1125                return copy_regset_to_user(child, &user_x86_32_view,
1126                                           REGSET_XFP, 0,
1127                                           sizeof(struct user32_fxsr_struct),
1128                                           datap);
1129
1130        case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1131                return copy_regset_from_user(child, &user_x86_32_view,
1132                                             REGSET_XFP, 0,
1133                                             sizeof(struct user32_fxsr_struct),
1134                                             datap);
1135
1136        case PTRACE_GET_THREAD_AREA:
1137        case PTRACE_SET_THREAD_AREA:
1138                return arch_ptrace(child, request, addr, data);
1139
1140        default:
1141                return compat_ptrace_request(child, request, addr, data);
1142        }
1143
1144        return ret;
1145}
1146#endif /* CONFIG_IA32_EMULATION */
1147
1148#ifdef CONFIG_X86_X32_ABI
1149static long x32_arch_ptrace(struct task_struct *child,
1150                            compat_long_t request, compat_ulong_t caddr,
1151                            compat_ulong_t cdata)
1152{
1153        unsigned long addr = caddr;
1154        unsigned long data = cdata;
1155        void __user *datap = compat_ptr(data);
1156        int ret;
1157
1158        switch (request) {
1159        /* Read 32bits at location addr in the USER area.  Only allow
1160           to return the lower 32bits of segment and debug registers.  */
1161        case PTRACE_PEEKUSR: {
1162                u32 tmp;
1163
1164                ret = -EIO;
1165                if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1166                    addr < offsetof(struct user_regs_struct, cs))
1167                        break;
1168
1169                tmp = 0;  /* Default return condition */
1170                if (addr < sizeof(struct user_regs_struct))
1171                        tmp = getreg(child, addr);
1172                else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1173                         addr <= offsetof(struct user, u_debugreg[7])) {
1174                        addr -= offsetof(struct user, u_debugreg[0]);
1175                        tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1176                }
1177                ret = put_user(tmp, (__u32 __user *)datap);
1178                break;
1179        }
1180
1181        /* Write the word at location addr in the USER area.  Only allow
1182           to update segment and debug registers with the upper 32bits
1183           zero-extended. */
1184        case PTRACE_POKEUSR:
1185                ret = -EIO;
1186                if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1187                    addr < offsetof(struct user_regs_struct, cs))
1188                        break;
1189
1190                if (addr < sizeof(struct user_regs_struct))
1191                        ret = putreg(child, addr, data);
1192                else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1193                         addr <= offsetof(struct user, u_debugreg[7])) {
1194                        addr -= offsetof(struct user, u_debugreg[0]);
1195                        ret = ptrace_set_debugreg(child,
1196                                                  addr / sizeof(data), data);
1197                }
1198                break;
1199
1200        case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1201                return copy_regset_to_user(child,
1202                                           task_user_regset_view(current),
1203                                           REGSET_GENERAL,
1204                                           0, sizeof(struct user_regs_struct),
1205                                           datap);
1206
1207        case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1208                return copy_regset_from_user(child,
1209                                             task_user_regset_view(current),
1210                                             REGSET_GENERAL,
1211                                             0, sizeof(struct user_regs_struct),
1212                                             datap);
1213
1214        case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1215                return copy_regset_to_user(child,
1216                                           task_user_regset_view(current),
1217                                           REGSET_FP,
1218                                           0, sizeof(struct user_i387_struct),
1219                                           datap);
1220
1221        case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1222                return copy_regset_from_user(child,
1223                                             task_user_regset_view(current),
1224                                             REGSET_FP,
1225                                             0, sizeof(struct user_i387_struct),
1226                                             datap);
1227
1228        default:
1229                return compat_ptrace_request(child, request, addr, data);
1230        }
1231
1232        return ret;
1233}
1234#endif
1235
1236#ifdef CONFIG_COMPAT
1237long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1238                        compat_ulong_t caddr, compat_ulong_t cdata)
1239{
1240#ifdef CONFIG_X86_X32_ABI
1241        if (!in_ia32_syscall())
1242                return x32_arch_ptrace(child, request, caddr, cdata);
1243#endif
1244#ifdef CONFIG_IA32_EMULATION
1245        return ia32_arch_ptrace(child, request, caddr, cdata);
1246#else
1247        return 0;
1248#endif
1249}
1250#endif  /* CONFIG_COMPAT */
1251
1252#ifdef CONFIG_X86_64
1253
1254static struct user_regset x86_64_regsets[] __ro_after_init = {
1255        [REGSET_GENERAL] = {
1256                .core_note_type = NT_PRSTATUS,
1257                .n = sizeof(struct user_regs_struct) / sizeof(long),
1258                .size = sizeof(long), .align = sizeof(long),
1259                .get = genregs_get, .set = genregs_set
1260        },
1261        [REGSET_FP] = {
1262                .core_note_type = NT_PRFPREG,
1263                .n = sizeof(struct user_i387_struct) / sizeof(long),
1264                .size = sizeof(long), .align = sizeof(long),
1265                .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1266        },
1267        [REGSET_XSTATE] = {
1268                .core_note_type = NT_X86_XSTATE,
1269                .size = sizeof(u64), .align = sizeof(u64),
1270                .active = xstateregs_active, .get = xstateregs_get,
1271                .set = xstateregs_set
1272        },
1273        [REGSET_IOPERM64] = {
1274                .core_note_type = NT_386_IOPERM,
1275                .n = IO_BITMAP_LONGS,
1276                .size = sizeof(long), .align = sizeof(long),
1277                .active = ioperm_active, .get = ioperm_get
1278        },
1279};
1280
1281static const struct user_regset_view user_x86_64_view = {
1282        .name = "x86_64", .e_machine = EM_X86_64,
1283        .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1284};
1285
1286#else  /* CONFIG_X86_32 */
1287
1288#define user_regs_struct32      user_regs_struct
1289#define genregs32_get           genregs_get
1290#define genregs32_set           genregs_set
1291
1292#endif  /* CONFIG_X86_64 */
1293
1294#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1295static struct user_regset x86_32_regsets[] __ro_after_init = {
1296        [REGSET_GENERAL] = {
1297                .core_note_type = NT_PRSTATUS,
1298                .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1299                .size = sizeof(u32), .align = sizeof(u32),
1300                .get = genregs32_get, .set = genregs32_set
1301        },
1302        [REGSET_FP] = {
1303                .core_note_type = NT_PRFPREG,
1304                .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1305                .size = sizeof(u32), .align = sizeof(u32),
1306                .active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1307        },
1308        [REGSET_XFP] = {
1309                .core_note_type = NT_PRXFPREG,
1310                .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1311                .size = sizeof(u32), .align = sizeof(u32),
1312                .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1313        },
1314        [REGSET_XSTATE] = {
1315                .core_note_type = NT_X86_XSTATE,
1316                .size = sizeof(u64), .align = sizeof(u64),
1317                .active = xstateregs_active, .get = xstateregs_get,
1318                .set = xstateregs_set
1319        },
1320        [REGSET_TLS] = {
1321                .core_note_type = NT_386_TLS,
1322                .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1323                .size = sizeof(struct user_desc),
1324                .align = sizeof(struct user_desc),
1325                .active = regset_tls_active,
1326                .get = regset_tls_get, .set = regset_tls_set
1327        },
1328        [REGSET_IOPERM32] = {
1329                .core_note_type = NT_386_IOPERM,
1330                .n = IO_BITMAP_BYTES / sizeof(u32),
1331                .size = sizeof(u32), .align = sizeof(u32),
1332                .active = ioperm_active, .get = ioperm_get
1333        },
1334};
1335
1336static const struct user_regset_view user_x86_32_view = {
1337        .name = "i386", .e_machine = EM_386,
1338        .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1339};
1340#endif
1341
1342/*
1343 * This represents bytes 464..511 in the memory layout exported through
1344 * the REGSET_XSTATE interface.
1345 */
1346u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1347
1348void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1349{
1350#ifdef CONFIG_X86_64
1351        x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1352#endif
1353#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1354        x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1355#endif
1356        xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1357}
1358
1359const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1360{
1361#ifdef CONFIG_IA32_EMULATION
1362        if (!user_64bit_mode(task_pt_regs(task)))
1363#endif
1364#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1365                return &user_x86_32_view;
1366#endif
1367#ifdef CONFIG_X86_64
1368        return &user_x86_64_view;
1369#endif
1370}
1371
1372static void fill_sigtrap_info(struct task_struct *tsk,
1373                                struct pt_regs *regs,
1374                                int error_code, int si_code,
1375                                struct siginfo *info)
1376{
1377        tsk->thread.trap_nr = X86_TRAP_DB;
1378        tsk->thread.error_code = error_code;
1379
1380        memset(info, 0, sizeof(*info));
1381        info->si_signo = SIGTRAP;
1382        info->si_code = si_code;
1383        info->si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
1384}
1385
1386void user_single_step_siginfo(struct task_struct *tsk,
1387                                struct pt_regs *regs,
1388                                struct siginfo *info)
1389{
1390        fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1391}
1392
1393void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1394                                         int error_code, int si_code)
1395{
1396        struct siginfo info;
1397
1398        fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1399        /* Send us the fake SIGTRAP */
1400        force_sig_info(SIGTRAP, &info, tsk);
1401}
1402