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/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 #include <asm/fsgsbase.h>
  43
  44 #include "tls.h"
  45
  46 enum x86_regset {
  47         REGSET_GENERAL,
  48         REGSET_FP,
  49         REGSET_XFP,
  50         REGSET_IOPERM64 = REGSET_XFP,
  51         REGSET_XSTATE,
  52         REGSET_TLS,
  53         REGSET_IOPERM32,
  54 };
  55
  56 struct pt_regs_offset {
  57         const char *name;
  58         int offset;
  59 };
  60
  61 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  62 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  63
  64 static const struct pt_regs_offset regoffset_table[] = {
  65 #ifdef CONFIG_X86_64
  66         REG_OFFSET_NAME(r15),
  67         REG_OFFSET_NAME(r14),
  68         REG_OFFSET_NAME(r13),
  69         REG_OFFSET_NAME(r12),
  70         REG_OFFSET_NAME(r11),
  71         REG_OFFSET_NAME(r10),
  72         REG_OFFSET_NAME(r9),
  73         REG_OFFSET_NAME(r8),
  74 #endif
  75         REG_OFFSET_NAME(bx),
  76         REG_OFFSET_NAME(cx),
  77         REG_OFFSET_NAME(dx),
  78         REG_OFFSET_NAME(si),
  79         REG_OFFSET_NAME(di),
  80         REG_OFFSET_NAME(bp),
  81         REG_OFFSET_NAME(ax),
  82 #ifdef CONFIG_X86_32
  83         REG_OFFSET_NAME(ds),
  84         REG_OFFSET_NAME(es),
  85         REG_OFFSET_NAME(fs),
  86         REG_OFFSET_NAME(gs),
  87 #endif
  88         REG_OFFSET_NAME(orig_ax),
  89         REG_OFFSET_NAME(ip),
  90         REG_OFFSET_NAME(cs),
  91         REG_OFFSET_NAME(flags),
  92         REG_OFFSET_NAME(sp),
  93         REG_OFFSET_NAME(ss),
  94         REG_OFFSET_END,
  95 };
  96
  97 /**
  98  * regs_query_register_offset() - query register offset from its name
  99  * @name:       the name of a register
 100  *
 101  * regs_query_register_offset() returns the offset of a register in struct
 102  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 103  */
 104 int regs_query_register_offset(const char *name)
 105 {
 106         const struct pt_regs_offset *roff;
 107         for (roff = regoffset_table; roff->name != NULL; roff++)
 108                 if (!strcmp(roff->name, name))
 109                         return roff->offset;
 110         return -EINVAL;
 111 }
 112
 113 /**
 114  * regs_query_register_name() - query register name from its offset
 115  * @offset:     the offset of a register in struct pt_regs.
 116  *
 117  * regs_query_register_name() returns the name of a register from its
 118  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 119  */
 120 const char *regs_query_register_name(unsigned int offset)
 121 {
 122         const struct pt_regs_offset *roff;
 123         for (roff = regoffset_table; roff->name != NULL; roff++)
 124                 if (roff->offset == offset)
 125                         return roff->name;
 126         return NULL;
 127 }
 128
 129 /*
 130  * does not yet catch signals sent when the child dies.
 131  * in exit.c or in signal.c.
 132  */
 133
 134 /*
 135  * Determines which flags the user has access to [1 = access, 0 = no access].
 136  */
 137 #define FLAG_MASK_32            ((unsigned long)                        \
 138                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
 139                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
 140                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
 141                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
 142                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
 143
 144 /*
 145  * Determines whether a value may be installed in a segment register.
 146  */
 147 static inline bool invalid_selector(u16 value)
 148 {
 149         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
 150 }
 151
 152 #ifdef CONFIG_X86_32
 153
 154 #define FLAG_MASK               FLAG_MASK_32
 155
 156 /*
 157  * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
 158  * when it traps.  The previous stack will be directly underneath the saved
 159  * registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
 160  *
 161  * Now, if the stack is empty, '&regs->sp' is out of range. In this
 162  * case we try to take the previous stack. To always return a non-null
 163  * stack pointer we fall back to regs as stack if no previous stack
 164  * exists.
 165  *
 166  * This is valid only for kernel mode traps.
 167  */
 168 unsigned long kernel_stack_pointer(struct pt_regs *regs)
 169 {
 170         unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
 171         unsigned long sp = (unsigned long)&regs->sp;
 172         u32 *prev_esp;
 173
 174         if (context == (sp & ~(THREAD_SIZE - 1)))
 175                 return sp;
 176
 177         prev_esp = (u32 *)(context);
 178         if (*prev_esp)
 179                 return (unsigned long)*prev_esp;
 180
 181         return (unsigned long)regs;
 182 }
 183 EXPORT_SYMBOL_GPL(kernel_stack_pointer);
 184
 185 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 186 {
 187         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 188         return &regs->bx + (regno >> 2);
 189 }
 190
 191 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 192 {
 193         /*
 194          * Returning the value truncates it to 16 bits.
 195          */
 196         unsigned int retval;
 197         if (offset != offsetof(struct user_regs_struct, gs))
 198                 retval = *pt_regs_access(task_pt_regs(task), offset);
 199         else {
 200                 if (task == current)
 201                         retval = get_user_gs(task_pt_regs(task));
 202                 else
 203                         retval = task_user_gs(task);
 204         }
 205         return retval;
 206 }
 207
 208 static int set_segment_reg(struct task_struct *task,
 209                            unsigned long offset, u16 value)
 210 {
 211         /*
 212          * The value argument was already truncated to 16 bits.
 213          */
 214         if (invalid_selector(value))
 215                 return -EIO;
 216
 217         /*
 218          * For %cs and %ss we cannot permit a null selector.
 219          * We can permit a bogus selector as long as it has USER_RPL.
 220          * Null selectors are fine for other segment registers, but
 221          * we will never get back to user mode with invalid %cs or %ss
 222          * and will take the trap in iret instead.  Much code relies
 223          * on user_mode() to distinguish a user trap frame (which can
 224          * safely use invalid selectors) from a kernel trap frame.
 225          */
 226         switch (offset) {
 227         case offsetof(struct user_regs_struct, cs):
 228         case offsetof(struct user_regs_struct, ss):
 229                 if (unlikely(value == 0))
 230                         return -EIO;
 231
 232         default:
 233                 *pt_regs_access(task_pt_regs(task), offset) = value;
 234                 break;
 235
 236         case offsetof(struct user_regs_struct, gs):
 237                 if (task == current)
 238                         set_user_gs(task_pt_regs(task), value);
 239                 else
 240                         task_user_gs(task) = value;
 241         }
 242
 243         return 0;
 244 }
 245
 246 #else  /* CONFIG_X86_64 */
 247
 248 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
 249
 250 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 251 {
 252         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 253         return &regs->r15 + (offset / sizeof(regs->r15));
 254 }
 255
 256 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 257 {
 258         /*
 259          * Returning the value truncates it to 16 bits.
 260          */
 261         unsigned int seg;
 262
 263         switch (offset) {
 264         case offsetof(struct user_regs_struct, fs):
 265                 if (task == current) {
 266                         /* Older gas can't assemble movq %?s,%r?? */
 267                         asm("movl %%fs,%0" : "=r" (seg));
 268                         return seg;
 269                 }
 270                 return task->thread.fsindex;
 271         case offsetof(struct user_regs_struct, gs):
 272                 if (task == current) {
 273                         asm("movl %%gs,%0" : "=r" (seg));
 274                         return seg;
 275                 }
 276                 return task->thread.gsindex;
 277         case offsetof(struct user_regs_struct, ds):
 278                 if (task == current) {
 279                         asm("movl %%ds,%0" : "=r" (seg));
 280                         return seg;
 281                 }
 282                 return task->thread.ds;
 283         case offsetof(struct user_regs_struct, es):
 284                 if (task == current) {
 285                         asm("movl %%es,%0" : "=r" (seg));
 286                         return seg;
 287                 }
 288                 return task->thread.es;
 289
 290         case offsetof(struct user_regs_struct, cs):
 291         case offsetof(struct user_regs_struct, ss):
 292                 break;
 293         }
 294         return *pt_regs_access(task_pt_regs(task), offset);
 295 }
 296
 297 static int set_segment_reg(struct task_struct *task,
 298                            unsigned long offset, u16 value)
 299 {
 300         /*
 301          * The value argument was already truncated to 16 bits.
 302          */
 303         if (invalid_selector(value))
 304                 return -EIO;
 305
 306         switch (offset) {
 307         case offsetof(struct user_regs_struct,fs):
 308                 task->thread.fsindex = value;
 309                 if (task == current)
 310                         loadsegment(fs, task->thread.fsindex);
 311                 break;
 312         case offsetof(struct user_regs_struct,gs):
 313                 task->thread.gsindex = value;
 314                 if (task == current)
 315                         load_gs_index(task->thread.gsindex);
 316                 break;
 317         case offsetof(struct user_regs_struct,ds):
 318                 task->thread.ds = value;
 319                 if (task == current)
 320                         loadsegment(ds, task->thread.ds);
 321                 break;
 322         case offsetof(struct user_regs_struct,es):
 323                 task->thread.es = value;
 324                 if (task == current)
 325                         loadsegment(es, task->thread.es);
 326                 break;
 327
 328                 /*
 329                  * Can't actually change these in 64-bit mode.
 330                  */
 331         case offsetof(struct user_regs_struct,cs):
 332                 if (unlikely(value == 0))
 333                         return -EIO;
 334                 task_pt_regs(task)->cs = value;
 335                 break;
 336         case offsetof(struct user_regs_struct,ss):
 337                 if (unlikely(value == 0))
 338                         return -EIO;
 339                 task_pt_regs(task)->ss = value;
 340                 break;
 341         }
 342
 343         return 0;
 344 }
 345
 346 #endif  /* CONFIG_X86_32 */
 347
 348 static unsigned long get_flags(struct task_struct *task)
 349 {
 350         unsigned long retval = task_pt_regs(task)->flags;
 351
 352         /*
 353          * If the debugger set TF, hide it from the readout.
 354          */
 355         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 356                 retval &= ~X86_EFLAGS_TF;
 357
 358         return retval;
 359 }
 360
 361 static int set_flags(struct task_struct *task, unsigned long value)
 362 {
 363         struct pt_regs *regs = task_pt_regs(task);
 364
 365         /*
 366          * If the user value contains TF, mark that
 367          * it was not "us" (the debugger) that set it.
 368          * If not, make sure it stays set if we had.
 369          */
 370         if (value & X86_EFLAGS_TF)
 371                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
 372         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 373                 value |= X86_EFLAGS_TF;
 374
 375         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 376
 377         return 0;
 378 }
 379
 380 static int putreg(struct task_struct *child,
 381                   unsigned long offset, unsigned long value)
 382 {
 383         switch (offset) {
 384         case offsetof(struct user_regs_struct, cs):
 385         case offsetof(struct user_regs_struct, ds):
 386         case offsetof(struct user_regs_struct, es):
 387         case offsetof(struct user_regs_struct, fs):
 388         case offsetof(struct user_regs_struct, gs):
 389         case offsetof(struct user_regs_struct, ss):
 390                 return set_segment_reg(child, offset, value);
 391
 392         case offsetof(struct user_regs_struct, flags):
 393                 return set_flags(child, value);
 394
 395 #ifdef CONFIG_X86_64
 396         case offsetof(struct user_regs_struct,fs_base):
 397                 if (value >= TASK_SIZE_MAX)
 398                         return -EIO;
 399                 /*
 400                  * When changing the FS base, use do_arch_prctl_64()
 401                  * to set the index to zero and to set the base
 402                  * as requested.
 403                  */
 404                 if (child->thread.fsbase != value)
 405                         return do_arch_prctl_64(child, ARCH_SET_FS, value);
 406                 return 0;
 407         case offsetof(struct user_regs_struct,gs_base):
 408                 /*
 409                  * Exactly the same here as the %fs handling above.
 410                  */
 411                 if (value >= TASK_SIZE_MAX)
 412                         return -EIO;
 413                 if (child->thread.gsbase != value)
 414                         return do_arch_prctl_64(child, ARCH_SET_GS, value);
 415                 return 0;
 416 #endif
 417         }
 418
 419         *pt_regs_access(task_pt_regs(child), offset) = value;
 420         return 0;
 421 }
 422
 423 static unsigned long getreg(struct task_struct *task, unsigned long offset)
 424 {
 425         switch (offset) {
 426         case offsetof(struct user_regs_struct, cs):
 427         case offsetof(struct user_regs_struct, ds):
 428         case offsetof(struct user_regs_struct, es):
 429         case offsetof(struct user_regs_struct, fs):
 430         case offsetof(struct user_regs_struct, gs):
 431         case offsetof(struct user_regs_struct, ss):
 432                 return get_segment_reg(task, offset);
 433
 434         case offsetof(struct user_regs_struct, flags):
 435                 return get_flags(task);
 436
 437 #ifdef CONFIG_X86_64
 438         case offsetof(struct user_regs_struct, fs_base):
 439                 return x86_fsbase_read_task(task);
 440         case offsetof(struct user_regs_struct, gs_base):
 441                 return x86_gsbase_read_task(task);
 442 #endif
 443         }
 444
 445         return *pt_regs_access(task_pt_regs(task), offset);
 446 }
 447
 448 static int genregs_get(struct task_struct *target,
 449                        const struct user_regset *regset,
 450                        unsigned int pos, unsigned int count,
 451                        void *kbuf, void __user *ubuf)
 452 {
 453         if (kbuf) {
 454                 unsigned long *k = kbuf;
 455                 while (count >= sizeof(*k)) {
 456                         *k++ = getreg(target, pos);
 457                         count -= sizeof(*k);
 458                         pos += sizeof(*k);
 459                 }
 460         } else {
 461                 unsigned long __user *u = ubuf;
 462                 while (count >= sizeof(*u)) {
 463                         if (__put_user(getreg(target, pos), u++))
 464                                 return -EFAULT;
 465                         count -= sizeof(*u);
 466                         pos += sizeof(*u);
 467                 }
 468         }
 469
 470         return 0;
 471 }
 472
 473 static int genregs_set(struct task_struct *target,
 474                        const struct user_regset *regset,
 475                        unsigned int pos, unsigned int count,
 476                        const void *kbuf, const void __user *ubuf)
 477 {
 478         int ret = 0;
 479         if (kbuf) {
 480                 const unsigned long *k = kbuf;
 481                 while (count >= sizeof(*k) && !ret) {
 482                         ret = putreg(target, pos, *k++);
 483                         count -= sizeof(*k);
 484                         pos += sizeof(*k);
 485                 }
 486         } else {
 487                 const unsigned long  __user *u = ubuf;
 488                 while (count >= sizeof(*u) && !ret) {
 489                         unsigned long word;
 490                         ret = __get_user(word, u++);
 491                         if (ret)
 492                                 break;
 493                         ret = putreg(target, pos, word);
 494                         count -= sizeof(*u);
 495                         pos += sizeof(*u);
 496                 }
 497         }
 498         return ret;
 499 }
 500
 501 static void ptrace_triggered(struct perf_event *bp,
 502                              struct perf_sample_data *data,
 503                              struct pt_regs *regs)
 504 {
 505         int i;
 506         struct thread_struct *thread = &(current->thread);
 507
 508         /*
 509          * Store in the virtual DR6 register the fact that the breakpoint
 510          * was hit so the thread's debugger will see it.
 511          */
 512         for (i = 0; i < HBP_NUM; i++) {
 513                 if (thread->ptrace_bps[i] == bp)
 514                         break;
 515         }
 516
 517         thread->debugreg6 |= (DR_TRAP0 << i);
 518 }
 519
 520 /*
 521  * Walk through every ptrace breakpoints for this thread and
 522  * build the dr7 value on top of their attributes.
 523  *
 524  */
 525 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 526 {
 527         int i;
 528         int dr7 = 0;
 529         struct arch_hw_breakpoint *info;
 530
 531         for (i = 0; i < HBP_NUM; i++) {
 532                 if (bp[i] && !bp[i]->attr.disabled) {
 533                         info = counter_arch_bp(bp[i]);
 534                         dr7 |= encode_dr7(i, info->len, info->type);
 535                 }
 536         }
 537
 538         return dr7;
 539 }
 540
 541 static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
 542                                         int len, int type, bool disabled)
 543 {
 544         int err, bp_len, bp_type;
 545
 546         err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
 547         if (!err) {
 548                 attr->bp_len = bp_len;
 549                 attr->bp_type = bp_type;
 550                 attr->disabled = disabled;
 551         }
 552
 553         return err;
 554 }
 555
 556 static struct perf_event *
 557 ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
 558                                 unsigned long addr, bool disabled)
 559 {
 560         struct perf_event_attr attr;
 561         int err;
 562
 563         ptrace_breakpoint_init(&attr);
 564         attr.bp_addr = addr;
 565
 566         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 567         if (err)
 568                 return ERR_PTR(err);
 569
 570         return register_user_hw_breakpoint(&attr, ptrace_triggered,
 571                                                  NULL, tsk);
 572 }
 573
 574 static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 575                                         int disabled)
 576 {
 577         struct perf_event_attr attr = bp->attr;
 578         int err;
 579
 580         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 581         if (err)
 582                 return err;
 583
 584         return modify_user_hw_breakpoint(bp, &attr);
 585 }
 586
 587 /*
 588  * Handle ptrace writes to debug register 7.
 589  */
 590 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 591 {
 592         struct thread_struct *thread = &tsk->thread;
 593         unsigned long old_dr7;
 594         bool second_pass = false;
 595         int i, rc, ret = 0;
 596
 597         data &= ~DR_CONTROL_RESERVED;
 598         old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 599
 600 restore:
 601         rc = 0;
 602         for (i = 0; i < HBP_NUM; i++) {
 603                 unsigned len, type;
 604                 bool disabled = !decode_dr7(data, i, &len, &type);
 605                 struct perf_event *bp = thread->ptrace_bps[i];
 606
 607                 if (!bp) {
 608                         if (disabled)
 609                                 continue;
 610
 611                         bp = ptrace_register_breakpoint(tsk,
 612                                         len, type, 0, disabled);
 613                         if (IS_ERR(bp)) {
 614                                 rc = PTR_ERR(bp);
 615                                 break;
 616                         }
 617
 618                         thread->ptrace_bps[i] = bp;
 619                         continue;
 620                 }
 621
 622                 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
 623                 if (rc)
 624                         break;
 625         }
 626
 627         /* Restore if the first pass failed, second_pass shouldn't fail. */
 628         if (rc && !WARN_ON(second_pass)) {
 629                 ret = rc;
 630                 data = old_dr7;
 631                 second_pass = true;
 632                 goto restore;
 633         }
 634
 635         return ret;
 636 }
 637
 638 /*
 639  * Handle PTRACE_PEEKUSR calls for the debug register area.
 640  */
 641 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 642 {
 643         struct thread_struct *thread = &tsk->thread;
 644         unsigned long val = 0;
 645
 646         if (n < HBP_NUM) {
 647                 struct perf_event *bp = thread->ptrace_bps[n];
 648
 649                 if (bp)
 650                         val = bp->hw.info.address;
 651         } else if (n == 6) {
 652                 val = thread->debugreg6;
 653         } else if (n == 7) {
 654                 val = thread->ptrace_dr7;
 655         }
 656         return val;
 657 }
 658
 659 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 660                                       unsigned long addr)
 661 {
 662         struct thread_struct *t = &tsk->thread;
 663         struct perf_event *bp = t->ptrace_bps[nr];
 664         int err = 0;
 665
 666         if (!bp) {
 667                 /*
 668                  * Put stub len and type to create an inactive but correct bp.
 669                  *
 670                  * CHECKME: the previous code returned -EIO if the addr wasn't
 671                  * a valid task virtual addr. The new one will return -EINVAL in
 672                  *  this case.
 673                  * -EINVAL may be what we want for in-kernel breakpoints users,
 674                  * but -EIO looks better for ptrace, since we refuse a register
 675                  * writing for the user. And anyway this is the previous
 676                  * behaviour.
 677                  */
 678                 bp = ptrace_register_breakpoint(tsk,
 679                                 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
 680                                 addr, true);
 681                 if (IS_ERR(bp))
 682                         err = PTR_ERR(bp);
 683                 else
 684                         t->ptrace_bps[nr] = bp;
 685         } else {
 686                 struct perf_event_attr attr = bp->attr;
 687
 688                 attr.bp_addr = addr;
 689                 err = modify_user_hw_breakpoint(bp, &attr);
 690         }
 691
 692         return err;
 693 }
 694
 695 /*
 696  * Handle PTRACE_POKEUSR calls for the debug register area.
 697  */
 698 static int ptrace_set_debugreg(struct task_struct *tsk, int n,
 699                                unsigned long val)
 700 {
 701         struct thread_struct *thread = &tsk->thread;
 702         /* There are no DR4 or DR5 registers */
 703         int rc = -EIO;
 704
 705         if (n < HBP_NUM) {
 706                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
 707         } else if (n == 6) {
 708                 thread->debugreg6 = val;
 709                 rc = 0;
 710         } else if (n == 7) {
 711                 rc = ptrace_write_dr7(tsk, val);
 712                 if (!rc)
 713                         thread->ptrace_dr7 = val;
 714         }
 715         return rc;
 716 }
 717
 718 /*
 719  * These access the current or another (stopped) task's io permission
 720  * bitmap for debugging or core dump.
 721  */
 722 static int ioperm_active(struct task_struct *target,
 723                          const struct user_regset *regset)
 724 {
 725         return target->thread.io_bitmap_max / regset->size;
 726 }
 727
 728 static int ioperm_get(struct task_struct *target,
 729                       const struct user_regset *regset,
 730                       unsigned int pos, unsigned int count,
 731                       void *kbuf, void __user *ubuf)
 732 {
 733         if (!target->thread.io_bitmap_ptr)
 734                 return -ENXIO;
 735
 736         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 737                                    target->thread.io_bitmap_ptr,
 738                                    0, IO_BITMAP_BYTES);
 739 }
 740
 741 /*
 742  * Called by kernel/ptrace.c when detaching..
 743  *
 744  * Make sure the single step bit is not set.
 745  */
 746 void ptrace_disable(struct task_struct *child)
 747 {
 748         user_disable_single_step(child);
 749 #ifdef TIF_SYSCALL_EMU
 750         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 751 #endif
 752 }
 753
 754 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 755 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 756 #endif
 757
 758 long arch_ptrace(struct task_struct *child, long request,
 759                  unsigned long addr, unsigned long data)
 760 {
 761         int ret;
 762         unsigned long __user *datap = (unsigned long __user *)data;
 763
 764         switch (request) {
 765         /* read the word at location addr in the USER area. */
 766         case PTRACE_PEEKUSR: {
 767                 unsigned long tmp;
 768
 769                 ret = -EIO;
 770                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 771                         break;
 772
 773                 tmp = 0;  /* Default return condition */
 774                 if (addr < sizeof(struct user_regs_struct))
 775                         tmp = getreg(child, addr);
 776                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 777                          addr <= offsetof(struct user, u_debugreg[7])) {
 778                         addr -= offsetof(struct user, u_debugreg[0]);
 779                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 780                 }
 781                 ret = put_user(tmp, datap);
 782                 break;
 783         }
 784
 785         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 786                 ret = -EIO;
 787                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 788                         break;
 789
 790                 if (addr < sizeof(struct user_regs_struct))
 791                         ret = putreg(child, addr, data);
 792                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 793                          addr <= offsetof(struct user, u_debugreg[7])) {
 794                         addr -= offsetof(struct user, u_debugreg[0]);
 795                         ret = ptrace_set_debugreg(child,
 796                                                   addr / sizeof(data), data);
 797                 }
 798                 break;
 799
 800         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 801                 return copy_regset_to_user(child,
 802                                            task_user_regset_view(current),
 803                                            REGSET_GENERAL,
 804                                            0, sizeof(struct user_regs_struct),
 805                                            datap);
 806
 807         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 808                 return copy_regset_from_user(child,
 809                                              task_user_regset_view(current),
 810                                              REGSET_GENERAL,
 811                                              0, sizeof(struct user_regs_struct),
 812                                              datap);
 813
 814         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 815                 return copy_regset_to_user(child,
 816                                            task_user_regset_view(current),
 817                                            REGSET_FP,
 818                                            0, sizeof(struct user_i387_struct),
 819                                            datap);
 820
 821         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 822                 return copy_regset_from_user(child,
 823                                              task_user_regset_view(current),
 824                                              REGSET_FP,
 825                                              0, sizeof(struct user_i387_struct),
 826                                              datap);
 827
 828 #ifdef CONFIG_X86_32
 829         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
 830                 return copy_regset_to_user(child, &user_x86_32_view,
 831                                            REGSET_XFP,
 832                                            0, sizeof(struct user_fxsr_struct),
 833                                            datap) ? -EIO : 0;
 834
 835         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
 836                 return copy_regset_from_user(child, &user_x86_32_view,
 837                                              REGSET_XFP,
 838                                              0, sizeof(struct user_fxsr_struct),
 839                                              datap) ? -EIO : 0;
 840 #endif
 841
 842 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 843         case PTRACE_GET_THREAD_AREA:
 844                 if ((int) addr < 0)
 845                         return -EIO;
 846                 ret = do_get_thread_area(child, addr,
 847                                         (struct user_desc __user *)data);
 848                 break;
 849
 850         case PTRACE_SET_THREAD_AREA:
 851                 if ((int) addr < 0)
 852                         return -EIO;
 853                 ret = do_set_thread_area(child, addr,
 854                                         (struct user_desc __user *)data, 0);
 855                 break;
 856 #endif
 857
 858 #ifdef CONFIG_X86_64
 859                 /* normal 64bit interface to access TLS data.
 860                    Works just like arch_prctl, except that the arguments
 861                    are reversed. */
 862         case PTRACE_ARCH_PRCTL:
 863                 ret = do_arch_prctl_64(child, data, addr);
 864                 break;
 865 #endif
 866
 867         default:
 868                 ret = ptrace_request(child, request, addr, data);
 869                 break;
 870         }
 871
 872         return ret;
 873 }
 874
 875 #ifdef CONFIG_IA32_EMULATION
 876
 877 #include <linux/compat.h>
 878 #include <linux/syscalls.h>
 879 #include <asm/ia32.h>
 880 #include <asm/user32.h>
 881
 882 #define R32(l,q)                                                        \
 883         case offsetof(struct user32, regs.l):                           \
 884                 regs->q = value; break
 885
 886 #define SEG32(rs)                                                       \
 887         case offsetof(struct user32, regs.rs):                          \
 888                 return set_segment_reg(child,                           \
 889                                        offsetof(struct user_regs_struct, rs), \
 890                                        value);                          \
 891                 break
 892
 893 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 894 {
 895         struct pt_regs *regs = task_pt_regs(child);
 896
 897         switch (regno) {
 898
 899         SEG32(cs);
 900         SEG32(ds);
 901         SEG32(es);
 902         SEG32(fs);
 903         SEG32(gs);
 904         SEG32(ss);
 905
 906         R32(ebx, bx);
 907         R32(ecx, cx);
 908         R32(edx, dx);
 909         R32(edi, di);
 910         R32(esi, si);
 911         R32(ebp, bp);
 912         R32(eax, ax);
 913         R32(eip, ip);
 914         R32(esp, sp);
 915
 916         case offsetof(struct user32, regs.orig_eax):
 917                 /*
 918                  * Warning: bizarre corner case fixup here.  A 32-bit
 919                  * debugger setting orig_eax to -1 wants to disable
 920                  * syscall restart.  Make sure that the syscall
 921                  * restart code sign-extends orig_ax.  Also make sure
 922                  * we interpret the -ERESTART* codes correctly if
 923                  * loaded into regs->ax in case the task is not
 924                  * actually still sitting at the exit from a 32-bit
 925                  * syscall with TS_COMPAT still set.
 926                  */
 927                 regs->orig_ax = value;
 928                 if (syscall_get_nr(child, regs) >= 0)
 929                         child->thread_info.status |= TS_I386_REGS_POKED;
 930                 break;
 931
 932         case offsetof(struct user32, regs.eflags):
 933                 return set_flags(child, value);
 934
 935         case offsetof(struct user32, u_debugreg[0]) ...
 936                 offsetof(struct user32, u_debugreg[7]):
 937                 regno -= offsetof(struct user32, u_debugreg[0]);
 938                 return ptrace_set_debugreg(child, regno / 4, value);
 939
 940         default:
 941                 if (regno > sizeof(struct user32) || (regno & 3))
 942                         return -EIO;
 943
 944                 /*
 945                  * Other dummy fields in the virtual user structure
 946                  * are ignored
 947                  */
 948                 break;
 949         }
 950         return 0;
 951 }
 952
 953 #undef R32
 954 #undef SEG32
 955
 956 #define R32(l,q)                                                        \
 957         case offsetof(struct user32, regs.l):                           \
 958                 *val = regs->q; break
 959
 960 #define SEG32(rs)                                                       \
 961         case offsetof(struct user32, regs.rs):                          \
 962                 *val = get_segment_reg(child,                           \
 963                                        offsetof(struct user_regs_struct, rs)); \
 964                 break
 965
 966 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 967 {
 968         struct pt_regs *regs = task_pt_regs(child);
 969
 970         switch (regno) {
 971
 972         SEG32(ds);
 973         SEG32(es);
 974         SEG32(fs);
 975         SEG32(gs);
 976
 977         R32(cs, cs);
 978         R32(ss, ss);
 979         R32(ebx, bx);
 980         R32(ecx, cx);
 981         R32(edx, dx);
 982         R32(edi, di);
 983         R32(esi, si);
 984         R32(ebp, bp);
 985         R32(eax, ax);
 986         R32(orig_eax, orig_ax);
 987         R32(eip, ip);
 988         R32(esp, sp);
 989
 990         case offsetof(struct user32, regs.eflags):
 991                 *val = get_flags(child);
 992                 break;
 993
 994         case offsetof(struct user32, u_debugreg[0]) ...
 995                 offsetof(struct user32, u_debugreg[7]):
 996                 regno -= offsetof(struct user32, u_debugreg[0]);
 997                 *val = ptrace_get_debugreg(child, regno / 4);
 998                 break;
 999
1000         default:
1001                 if (regno > sizeof(struct user32) || (regno & 3))
1002                         return -EIO;
1003
1004                 /*
1005                  * Other dummy fields in the virtual user structure
1006                  * are ignored
1007                  */
1008                 *val = 0;
1009                 break;
1010         }
1011         return 0;
1012 }
1013
1014 #undef R32
1015 #undef SEG32
1016
1017 static int genregs32_get(struct task_struct *target,
1018                          const struct user_regset *regset,
1019                          unsigned int pos, unsigned int count,
1020                          void *kbuf, void __user *ubuf)
1021 {
1022         if (kbuf) {
1023                 compat_ulong_t *k = kbuf;
1024                 while (count >= sizeof(*k)) {
1025                         getreg32(target, pos, k++);
1026                         count -= sizeof(*k);
1027                         pos += sizeof(*k);
1028                 }
1029         } else {
1030                 compat_ulong_t __user *u = ubuf;
1031                 while (count >= sizeof(*u)) {
1032                         compat_ulong_t word;
1033                         getreg32(target, pos, &word);
1034                         if (__put_user(word, u++))
1035                                 return -EFAULT;
1036                         count -= sizeof(*u);
1037                         pos += sizeof(*u);
1038                 }
1039         }
1040
1041         return 0;
1042 }
1043
1044 static int genregs32_set(struct task_struct *target,
1045                          const struct user_regset *regset,
1046                          unsigned int pos, unsigned int count,
1047                          const void *kbuf, const void __user *ubuf)
1048 {
1049         int ret = 0;
1050         if (kbuf) {
1051                 const compat_ulong_t *k = kbuf;
1052                 while (count >= sizeof(*k) && !ret) {
1053                         ret = putreg32(target, pos, *k++);
1054                         count -= sizeof(*k);
1055                         pos += sizeof(*k);
1056                 }
1057         } else {
1058                 const compat_ulong_t __user *u = ubuf;
1059                 while (count >= sizeof(*u) && !ret) {
1060                         compat_ulong_t word;
1061                         ret = __get_user(word, u++);
1062                         if (ret)
1063                                 break;
1064                         ret = putreg32(target, pos, word);
1065                         count -= sizeof(*u);
1066                         pos += sizeof(*u);
1067                 }
1068         }
1069         return ret;
1070 }
1071
1072 static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1073                              compat_ulong_t caddr, compat_ulong_t cdata)
1074 {
1075         unsigned long addr = caddr;
1076         unsigned long data = cdata;
1077         void __user *datap = compat_ptr(data);
1078         int ret;
1079         __u32 val;
1080
1081         switch (request) {
1082         case PTRACE_PEEKUSR:
1083                 ret = getreg32(child, addr, &val);
1084                 if (ret == 0)
1085                         ret = put_user(val, (__u32 __user *)datap);
1086                 break;
1087
1088         case PTRACE_POKEUSR:
1089                 ret = putreg32(child, addr, data);
1090                 break;
1091
1092         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1093                 return copy_regset_to_user(child, &user_x86_32_view,
1094                                            REGSET_GENERAL,
1095                                            0, sizeof(struct user_regs_struct32),
1096                                            datap);
1097
1098         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1099                 return copy_regset_from_user(child, &user_x86_32_view,
1100                                              REGSET_GENERAL, 0,
1101                                              sizeof(struct user_regs_struct32),
1102                                              datap);
1103
1104         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1105                 return copy_regset_to_user(child, &user_x86_32_view,
1106                                            REGSET_FP, 0,
1107                                            sizeof(struct user_i387_ia32_struct),
1108                                            datap);
1109
1110         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1111                 return copy_regset_from_user(
1112                         child, &user_x86_32_view, REGSET_FP,
1113                         0, sizeof(struct user_i387_ia32_struct), datap);
1114
1115         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1116                 return copy_regset_to_user(child, &user_x86_32_view,
1117                                            REGSET_XFP, 0,
1118                                            sizeof(struct user32_fxsr_struct),
1119                                            datap);
1120
1121         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1122                 return copy_regset_from_user(child, &user_x86_32_view,
1123                                              REGSET_XFP, 0,
1124                                              sizeof(struct user32_fxsr_struct),
1125                                              datap);
1126
1127         case PTRACE_GET_THREAD_AREA:
1128         case PTRACE_SET_THREAD_AREA:
1129                 return arch_ptrace(child, request, addr, data);
1130
1131         default:
1132                 return compat_ptrace_request(child, request, addr, data);
1133         }
1134
1135         return ret;
1136 }
1137 #endif /* CONFIG_IA32_EMULATION */
1138
1139 #ifdef CONFIG_X86_X32_ABI
1140 static long x32_arch_ptrace(struct task_struct *child,
1141                             compat_long_t request, compat_ulong_t caddr,
1142                             compat_ulong_t cdata)
1143 {
1144         unsigned long addr = caddr;
1145         unsigned long data = cdata;
1146         void __user *datap = compat_ptr(data);
1147         int ret;
1148
1149         switch (request) {
1150         /* Read 32bits at location addr in the USER area.  Only allow
1151            to return the lower 32bits of segment and debug registers.  */
1152         case PTRACE_PEEKUSR: {
1153                 u32 tmp;
1154
1155                 ret = -EIO;
1156                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1157                     addr < offsetof(struct user_regs_struct, cs))
1158                         break;
1159
1160                 tmp = 0;  /* Default return condition */
1161                 if (addr < sizeof(struct user_regs_struct))
1162                         tmp = getreg(child, addr);
1163                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1164                          addr <= offsetof(struct user, u_debugreg[7])) {
1165                         addr -= offsetof(struct user, u_debugreg[0]);
1166                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1167                 }
1168                 ret = put_user(tmp, (__u32 __user *)datap);
1169                 break;
1170         }
1171
1172         /* Write the word at location addr in the USER area.  Only allow
1173            to update segment and debug registers with the upper 32bits
1174            zero-extended. */
1175         case PTRACE_POKEUSR:
1176                 ret = -EIO;
1177                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1178                     addr < offsetof(struct user_regs_struct, cs))
1179                         break;
1180
1181                 if (addr < sizeof(struct user_regs_struct))
1182                         ret = putreg(child, addr, data);
1183                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1184                          addr <= offsetof(struct user, u_debugreg[7])) {
1185                         addr -= offsetof(struct user, u_debugreg[0]);
1186                         ret = ptrace_set_debugreg(child,
1187                                                   addr / sizeof(data), data);
1188                 }
1189                 break;
1190
1191         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1192                 return copy_regset_to_user(child,
1193                                            task_user_regset_view(current),
1194                                            REGSET_GENERAL,
1195                                            0, sizeof(struct user_regs_struct),
1196                                            datap);
1197
1198         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1199                 return copy_regset_from_user(child,
1200                                              task_user_regset_view(current),
1201                                              REGSET_GENERAL,
1202                                              0, sizeof(struct user_regs_struct),
1203                                              datap);
1204
1205         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1206                 return copy_regset_to_user(child,
1207                                            task_user_regset_view(current),
1208                                            REGSET_FP,
1209                                            0, sizeof(struct user_i387_struct),
1210                                            datap);
1211
1212         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1213                 return copy_regset_from_user(child,
1214                                              task_user_regset_view(current),
1215                                              REGSET_FP,
1216                                              0, sizeof(struct user_i387_struct),
1217                                              datap);
1218
1219         default:
1220                 return compat_ptrace_request(child, request, addr, data);
1221         }
1222
1223         return ret;
1224 }
1225 #endif
1226
1227 #ifdef CONFIG_COMPAT
1228 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1229                         compat_ulong_t caddr, compat_ulong_t cdata)
1230 {
1231 #ifdef CONFIG_X86_X32_ABI
1232         if (!in_ia32_syscall())
1233                 return x32_arch_ptrace(child, request, caddr, cdata);
1234 #endif
1235 #ifdef CONFIG_IA32_EMULATION
1236         return ia32_arch_ptrace(child, request, caddr, cdata);
1237 #else
1238         return 0;
1239 #endif
1240 }
1241 #endif  /* CONFIG_COMPAT */
1242
1243 #ifdef CONFIG_X86_64
1244
1245 static struct user_regset x86_64_regsets[] __ro_after_init = {
1246         [REGSET_GENERAL] = {
1247                 .core_note_type = NT_PRSTATUS,
1248                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1249                 .size = sizeof(long), .align = sizeof(long),
1250                 .get = genregs_get, .set = genregs_set
1251         },
1252         [REGSET_FP] = {
1253                 .core_note_type = NT_PRFPREG,
1254                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1255                 .size = sizeof(long), .align = sizeof(long),
1256                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1257         },
1258         [REGSET_XSTATE] = {
1259                 .core_note_type = NT_X86_XSTATE,
1260                 .size = sizeof(u64), .align = sizeof(u64),
1261                 .active = xstateregs_active, .get = xstateregs_get,
1262                 .set = xstateregs_set
1263         },
1264         [REGSET_IOPERM64] = {
1265                 .core_note_type = NT_386_IOPERM,
1266                 .n = IO_BITMAP_LONGS,
1267                 .size = sizeof(long), .align = sizeof(long),
1268                 .active = ioperm_active, .get = ioperm_get
1269         },
1270 };
1271
1272 static const struct user_regset_view user_x86_64_view = {
1273         .name = "x86_64", .e_machine = EM_X86_64,
1274         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1275 };
1276
1277 #else  /* CONFIG_X86_32 */
1278
1279 #define user_regs_struct32      user_regs_struct
1280 #define genregs32_get           genregs_get
1281 #define genregs32_set           genregs_set
1282
1283 #endif  /* CONFIG_X86_64 */
1284
1285 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1286 static struct user_regset x86_32_regsets[] __ro_after_init = {
1287         [REGSET_GENERAL] = {
1288                 .core_note_type = NT_PRSTATUS,
1289                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1290                 .size = sizeof(u32), .align = sizeof(u32),
1291                 .get = genregs32_get, .set = genregs32_set
1292         },
1293         [REGSET_FP] = {
1294                 .core_note_type = NT_PRFPREG,
1295                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1296                 .size = sizeof(u32), .align = sizeof(u32),
1297                 .active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1298         },
1299         [REGSET_XFP] = {
1300                 .core_note_type = NT_PRXFPREG,
1301                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1302                 .size = sizeof(u32), .align = sizeof(u32),
1303                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1304         },
1305         [REGSET_XSTATE] = {
1306                 .core_note_type = NT_X86_XSTATE,
1307                 .size = sizeof(u64), .align = sizeof(u64),
1308                 .active = xstateregs_active, .get = xstateregs_get,
1309                 .set = xstateregs_set
1310         },
1311         [REGSET_TLS] = {
1312                 .core_note_type = NT_386_TLS,
1313                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1314                 .size = sizeof(struct user_desc),
1315                 .align = sizeof(struct user_desc),
1316                 .active = regset_tls_active,
1317                 .get = regset_tls_get, .set = regset_tls_set
1318         },
1319         [REGSET_IOPERM32] = {
1320                 .core_note_type = NT_386_IOPERM,
1321                 .n = IO_BITMAP_BYTES / sizeof(u32),
1322                 .size = sizeof(u32), .align = sizeof(u32),
1323                 .active = ioperm_active, .get = ioperm_get
1324         },
1325 };
1326
1327 static const struct user_regset_view user_x86_32_view = {
1328         .name = "i386", .e_machine = EM_386,
1329         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1330 };
1331 #endif
1332
1333 /*
1334  * This represents bytes 464..511 in the memory layout exported through
1335  * the REGSET_XSTATE interface.
1336  */
1337 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1338
1339 void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1340 {
1341 #ifdef CONFIG_X86_64
1342         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1343 #endif
1344 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1345         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1346 #endif
1347         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1348 }
1349
1350 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1351 {
1352 #ifdef CONFIG_IA32_EMULATION
1353         if (!user_64bit_mode(task_pt_regs(task)))
1354 #endif
1355 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1356                 return &user_x86_32_view;
1357 #endif
1358 #ifdef CONFIG_X86_64
1359         return &user_x86_64_view;
1360 #endif
1361 }
1362
1363 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1364                                          int error_code, int si_code)
1365 {
1366         tsk->thread.trap_nr = X86_TRAP_DB;
1367         tsk->thread.error_code = error_code;
1368
1369         /* Send us the fake SIGTRAP */
1370         force_sig_fault(SIGTRAP, si_code,
1371                         user_mode(regs) ? (void __user *)regs->ip : NULL, tsk);
1372 }
1373
1374 void user_single_step_report(struct pt_regs *regs)
1375 {
1376         send_sigtrap(current, regs, 0, TRAP_BRKPT);
1377 }