arch/x86/kernel/ptrace.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* By Ross Biro 1/23/92 */
   3 /*
   4  * Pentium III FXSR, SSE support
   5  *      Gareth Hughes <gareth@valinux.com>, May 2000
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/sched.h>
  10 #include <linux/sched/task_stack.h>
  11 #include <linux/mm.h>
  12 #include <linux/smp.h>
  13 #include <linux/errno.h>
  14 #include <linux/slab.h>
  15 #include <linux/ptrace.h>
  16 #include <linux/tracehook.h>
  17 #include <linux/user.h>
  18 #include <linux/elf.h>
  19 #include <linux/security.h>
  20 #include <linux/audit.h>
  21 #include <linux/seccomp.h>
  22 #include <linux/signal.h>
  23 #include <linux/perf_event.h>
  24 #include <linux/hw_breakpoint.h>
  25 #include <linux/rcupdate.h>
  26 #include <linux/export.h>
  27 #include <linux/context_tracking.h>
  28 #include <linux/nospec.h>
  29
  30 #include <linux/uaccess.h>
  31 #include <asm/pgtable.h>
  32 #include <asm/processor.h>
  33 #include <asm/fpu/internal.h>
  34 #include <asm/fpu/signal.h>
  35 #include <asm/fpu/regset.h>
  36 #include <asm/debugreg.h>
  37 #include <asm/ldt.h>
  38 #include <asm/desc.h>
  39 #include <asm/prctl.h>
  40 #include <asm/proto.h>
  41 #include <asm/hw_breakpoint.h>
  42 #include <asm/traps.h>
  43 #include <asm/syscall.h>
  44 #include <asm/fsgsbase.h>
  45
  46 #include "tls.h"
  47
  48 enum x86_regset {
  49         REGSET_GENERAL,
  50         REGSET_FP,
  51         REGSET_XFP,
  52         REGSET_IOPERM64 = REGSET_XFP,
  53         REGSET_XSTATE,
  54         REGSET_TLS,
  55         REGSET_IOPERM32,
  56 };
  57
  58 struct pt_regs_offset {
  59         const char *name;
  60         int offset;
  61 };
  62
  63 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  64 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  65
  66 static const struct pt_regs_offset regoffset_table[] = {
  67 #ifdef CONFIG_X86_64
  68         REG_OFFSET_NAME(r15),
  69         REG_OFFSET_NAME(r14),
  70         REG_OFFSET_NAME(r13),
  71         REG_OFFSET_NAME(r12),
  72         REG_OFFSET_NAME(r11),
  73         REG_OFFSET_NAME(r10),
  74         REG_OFFSET_NAME(r9),
  75         REG_OFFSET_NAME(r8),
  76 #endif
  77         REG_OFFSET_NAME(bx),
  78         REG_OFFSET_NAME(cx),
  79         REG_OFFSET_NAME(dx),
  80         REG_OFFSET_NAME(si),
  81         REG_OFFSET_NAME(di),
  82         REG_OFFSET_NAME(bp),
  83         REG_OFFSET_NAME(ax),
  84 #ifdef CONFIG_X86_32
  85         REG_OFFSET_NAME(ds),
  86         REG_OFFSET_NAME(es),
  87         REG_OFFSET_NAME(fs),
  88         REG_OFFSET_NAME(gs),
  89 #endif
  90         REG_OFFSET_NAME(orig_ax),
  91         REG_OFFSET_NAME(ip),
  92         REG_OFFSET_NAME(cs),
  93         REG_OFFSET_NAME(flags),
  94         REG_OFFSET_NAME(sp),
  95         REG_OFFSET_NAME(ss),
  96         REG_OFFSET_END,
  97 };
  98
  99 /**
 100  * regs_query_register_offset() - query register offset from its name
 101  * @name:       the name of a register
 102  *
 103  * regs_query_register_offset() returns the offset of a register in struct
 104  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 105  */
 106 int regs_query_register_offset(const char *name)
 107 {
 108         const struct pt_regs_offset *roff;
 109         for (roff = regoffset_table; roff->name != NULL; roff++)
 110                 if (!strcmp(roff->name, name))
 111                         return roff->offset;
 112         return -EINVAL;
 113 }
 114
 115 /**
 116  * regs_query_register_name() - query register name from its offset
 117  * @offset:     the offset of a register in struct pt_regs.
 118  *
 119  * regs_query_register_name() returns the name of a register from its
 120  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 121  */
 122 const char *regs_query_register_name(unsigned int offset)
 123 {
 124         const struct pt_regs_offset *roff;
 125         for (roff = regoffset_table; roff->name != NULL; roff++)
 126                 if (roff->offset == offset)
 127                         return roff->name;
 128         return NULL;
 129 }
 130
 131 /*
 132  * does not yet catch signals sent when the child dies.
 133  * in exit.c or in signal.c.
 134  */
 135
 136 /*
 137  * Determines which flags the user has access to [1 = access, 0 = no access].
 138  */
 139 #define FLAG_MASK_32            ((unsigned long)                        \
 140                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
 141                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
 142                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
 143                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
 144                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
 145
 146 /*
 147  * Determines whether a value may be installed in a segment register.
 148  */
 149 static inline bool invalid_selector(u16 value)
 150 {
 151         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
 152 }
 153
 154 #ifdef CONFIG_X86_32
 155
 156 #define FLAG_MASK               FLAG_MASK_32
 157
 158 /*
 159  * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
 160  * when it traps.  The previous stack will be directly underneath the saved
 161  * registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
 162  *
 163  * Now, if the stack is empty, '&regs->sp' is out of range. In this
 164  * case we try to take the previous stack. To always return a non-null
 165  * stack pointer we fall back to regs as stack if no previous stack
 166  * exists.
 167  *
 168  * This is valid only for kernel mode traps.
 169  */
 170 unsigned long kernel_stack_pointer(struct pt_regs *regs)
 171 {
 172         unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
 173         unsigned long sp = (unsigned long)&regs->sp;
 174         u32 *prev_esp;
 175
 176         if (context == (sp & ~(THREAD_SIZE - 1)))
 177                 return sp;
 178
 179         prev_esp = (u32 *)(context);
 180         if (*prev_esp)
 181                 return (unsigned long)*prev_esp;
 182
 183         return (unsigned long)regs;
 184 }
 185 EXPORT_SYMBOL_GPL(kernel_stack_pointer);
 186
 187 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 188 {
 189         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 190         return &regs->bx + (regno >> 2);
 191 }
 192
 193 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 194 {
 195         /*
 196          * Returning the value truncates it to 16 bits.
 197          */
 198         unsigned int retval;
 199         if (offset != offsetof(struct user_regs_struct, gs))
 200                 retval = *pt_regs_access(task_pt_regs(task), offset);
 201         else {
 202                 if (task == current)
 203                         retval = get_user_gs(task_pt_regs(task));
 204                 else
 205                         retval = task_user_gs(task);
 206         }
 207         return retval;
 208 }
 209
 210 static int set_segment_reg(struct task_struct *task,
 211                            unsigned long offset, u16 value)
 212 {
 213         /*
 214          * The value argument was already truncated to 16 bits.
 215          */
 216         if (invalid_selector(value))
 217                 return -EIO;
 218
 219         /*
 220          * For %cs and %ss we cannot permit a null selector.
 221          * We can permit a bogus selector as long as it has USER_RPL.
 222          * Null selectors are fine for other segment registers, but
 223          * we will never get back to user mode with invalid %cs or %ss
 224          * and will take the trap in iret instead.  Much code relies
 225          * on user_mode() to distinguish a user trap frame (which can
 226          * safely use invalid selectors) from a kernel trap frame.
 227          */
 228         switch (offset) {
 229         case offsetof(struct user_regs_struct, cs):
 230         case offsetof(struct user_regs_struct, ss):
 231                 if (unlikely(value == 0))
 232                         return -EIO;
 233
 234         default:
 235                 *pt_regs_access(task_pt_regs(task), offset) = value;
 236                 break;
 237
 238         case offsetof(struct user_regs_struct, gs):
 239                 if (task == current)
 240                         set_user_gs(task_pt_regs(task), value);
 241                 else
 242                         task_user_gs(task) = value;
 243         }
 244
 245         return 0;
 246 }
 247
 248 #else  /* CONFIG_X86_64 */
 249
 250 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
 251
 252 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 253 {
 254         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 255         return &regs->r15 + (offset / sizeof(regs->r15));
 256 }
 257
 258 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 259 {
 260         /*
 261          * Returning the value truncates it to 16 bits.
 262          */
 263         unsigned int seg;
 264
 265         switch (offset) {
 266         case offsetof(struct user_regs_struct, fs):
 267                 if (task == current) {
 268                         /* Older gas can't assemble movq %?s,%r?? */
 269                         asm("movl %%fs,%0" : "=r" (seg));
 270                         return seg;
 271                 }
 272                 return task->thread.fsindex;
 273         case offsetof(struct user_regs_struct, gs):
 274                 if (task == current) {
 275                         asm("movl %%gs,%0" : "=r" (seg));
 276                         return seg;
 277                 }
 278                 return task->thread.gsindex;
 279         case offsetof(struct user_regs_struct, ds):
 280                 if (task == current) {
 281                         asm("movl %%ds,%0" : "=r" (seg));
 282                         return seg;
 283                 }
 284                 return task->thread.ds;
 285         case offsetof(struct user_regs_struct, es):
 286                 if (task == current) {
 287                         asm("movl %%es,%0" : "=r" (seg));
 288                         return seg;
 289                 }
 290                 return task->thread.es;
 291
 292         case offsetof(struct user_regs_struct, cs):
 293         case offsetof(struct user_regs_struct, ss):
 294                 break;
 295         }
 296         return *pt_regs_access(task_pt_regs(task), offset);
 297 }
 298
 299 static int set_segment_reg(struct task_struct *task,
 300                            unsigned long offset, u16 value)
 301 {
 302         /*
 303          * The value argument was already truncated to 16 bits.
 304          */
 305         if (invalid_selector(value))
 306                 return -EIO;
 307
 308         switch (offset) {
 309         case offsetof(struct user_regs_struct,fs):
 310                 task->thread.fsindex = value;
 311                 if (task == current)
 312                         loadsegment(fs, task->thread.fsindex);
 313                 break;
 314         case offsetof(struct user_regs_struct,gs):
 315                 task->thread.gsindex = value;
 316                 if (task == current)
 317                         load_gs_index(task->thread.gsindex);
 318                 break;
 319         case offsetof(struct user_regs_struct,ds):
 320                 task->thread.ds = value;
 321                 if (task == current)
 322                         loadsegment(ds, task->thread.ds);
 323                 break;
 324         case offsetof(struct user_regs_struct,es):
 325                 task->thread.es = value;
 326                 if (task == current)
 327                         loadsegment(es, task->thread.es);
 328                 break;
 329
 330                 /*
 331                  * Can't actually change these in 64-bit mode.
 332                  */
 333         case offsetof(struct user_regs_struct,cs):
 334                 if (unlikely(value == 0))
 335                         return -EIO;
 336                 task_pt_regs(task)->cs = value;
 337                 break;
 338         case offsetof(struct user_regs_struct,ss):
 339                 if (unlikely(value == 0))
 340                         return -EIO;
 341                 task_pt_regs(task)->ss = value;
 342                 break;
 343         }
 344
 345         return 0;
 346 }
 347
 348 #endif  /* CONFIG_X86_32 */
 349
 350 static unsigned long get_flags(struct task_struct *task)
 351 {
 352         unsigned long retval = task_pt_regs(task)->flags;
 353
 354         /*
 355          * If the debugger set TF, hide it from the readout.
 356          */
 357         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 358                 retval &= ~X86_EFLAGS_TF;
 359
 360         return retval;
 361 }
 362
 363 static int set_flags(struct task_struct *task, unsigned long value)
 364 {
 365         struct pt_regs *regs = task_pt_regs(task);
 366
 367         /*
 368          * If the user value contains TF, mark that
 369          * it was not "us" (the debugger) that set it.
 370          * If not, make sure it stays set if we had.
 371          */
 372         if (value & X86_EFLAGS_TF)
 373                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
 374         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 375                 value |= X86_EFLAGS_TF;
 376
 377         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 378
 379         return 0;
 380 }
 381
 382 static int putreg(struct task_struct *child,
 383                   unsigned long offset, unsigned long value)
 384 {
 385         switch (offset) {
 386         case offsetof(struct user_regs_struct, cs):
 387         case offsetof(struct user_regs_struct, ds):
 388         case offsetof(struct user_regs_struct, es):
 389         case offsetof(struct user_regs_struct, fs):
 390         case offsetof(struct user_regs_struct, gs):
 391         case offsetof(struct user_regs_struct, ss):
 392                 return set_segment_reg(child, offset, value);
 393
 394         case offsetof(struct user_regs_struct, flags):
 395                 return set_flags(child, value);
 396
 397 #ifdef CONFIG_X86_64
 398         case offsetof(struct user_regs_struct,fs_base):
 399                 if (value >= TASK_SIZE_MAX)
 400                         return -EIO;
 401                 /*
 402                  * When changing the FS base, use do_arch_prctl_64()
 403                  * to set the index to zero and to set the base
 404                  * as requested.
 405                  */
 406                 if (child->thread.fsbase != value)
 407                         return do_arch_prctl_64(child, ARCH_SET_FS, value);
 408                 return 0;
 409         case offsetof(struct user_regs_struct,gs_base):
 410                 /*
 411                  * Exactly the same here as the %fs handling above.
 412                  */
 413                 if (value >= TASK_SIZE_MAX)
 414                         return -EIO;
 415                 if (child->thread.gsbase != value)
 416                         return do_arch_prctl_64(child, ARCH_SET_GS, value);
 417                 return 0;
 418 #endif
 419         }
 420
 421         *pt_regs_access(task_pt_regs(child), offset) = value;
 422         return 0;
 423 }
 424
 425 static unsigned long getreg(struct task_struct *task, unsigned long offset)
 426 {
 427         switch (offset) {
 428         case offsetof(struct user_regs_struct, cs):
 429         case offsetof(struct user_regs_struct, ds):
 430         case offsetof(struct user_regs_struct, es):
 431         case offsetof(struct user_regs_struct, fs):
 432         case offsetof(struct user_regs_struct, gs):
 433         case offsetof(struct user_regs_struct, ss):
 434                 return get_segment_reg(task, offset);
 435
 436         case offsetof(struct user_regs_struct, flags):
 437                 return get_flags(task);
 438
 439 #ifdef CONFIG_X86_64
 440         case offsetof(struct user_regs_struct, fs_base):
 441                 return x86_fsbase_read_task(task);
 442         case offsetof(struct user_regs_struct, gs_base):
 443                 return x86_gsbase_read_task(task);
 444 #endif
 445         }
 446
 447         return *pt_regs_access(task_pt_regs(task), offset);
 448 }
 449
 450 static int genregs_get(struct task_struct *target,
 451                        const struct user_regset *regset,
 452                        unsigned int pos, unsigned int count,
 453                        void *kbuf, void __user *ubuf)
 454 {
 455         if (kbuf) {
 456                 unsigned long *k = kbuf;
 457                 while (count >= sizeof(*k)) {
 458                         *k++ = getreg(target, pos);
 459                         count -= sizeof(*k);
 460                         pos += sizeof(*k);
 461                 }
 462         } else {
 463                 unsigned long __user *u = ubuf;
 464                 while (count >= sizeof(*u)) {
 465                         if (__put_user(getreg(target, pos), u++))
 466                                 return -EFAULT;
 467                         count -= sizeof(*u);
 468                         pos += sizeof(*u);
 469                 }
 470         }
 471
 472         return 0;
 473 }
 474
 475 static int genregs_set(struct task_struct *target,
 476                        const struct user_regset *regset,
 477                        unsigned int pos, unsigned int count,
 478                        const void *kbuf, const void __user *ubuf)
 479 {
 480         int ret = 0;
 481         if (kbuf) {
 482                 const unsigned long *k = kbuf;
 483                 while (count >= sizeof(*k) && !ret) {
 484                         ret = putreg(target, pos, *k++);
 485                         count -= sizeof(*k);
 486                         pos += sizeof(*k);
 487                 }
 488         } else {
 489                 const unsigned long  __user *u = ubuf;
 490                 while (count >= sizeof(*u) && !ret) {
 491                         unsigned long word;
 492                         ret = __get_user(word, u++);
 493                         if (ret)
 494                                 break;
 495                         ret = putreg(target, pos, word);
 496                         count -= sizeof(*u);
 497                         pos += sizeof(*u);
 498                 }
 499         }
 500         return ret;
 501 }
 502
 503 static void ptrace_triggered(struct perf_event *bp,
 504                              struct perf_sample_data *data,
 505                              struct pt_regs *regs)
 506 {
 507         int i;
 508         struct thread_struct *thread = &(current->thread);
 509
 510         /*
 511          * Store in the virtual DR6 register the fact that the breakpoint
 512          * was hit so the thread's debugger will see it.
 513          */
 514         for (i = 0; i < HBP_NUM; i++) {
 515                 if (thread->ptrace_bps[i] == bp)
 516                         break;
 517         }
 518
 519         thread->debugreg6 |= (DR_TRAP0 << i);
 520 }
 521
 522 /*
 523  * Walk through every ptrace breakpoints for this thread and
 524  * build the dr7 value on top of their attributes.
 525  *
 526  */
 527 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 528 {
 529         int i;
 530         int dr7 = 0;
 531         struct arch_hw_breakpoint *info;
 532
 533         for (i = 0; i < HBP_NUM; i++) {
 534                 if (bp[i] && !bp[i]->attr.disabled) {
 535                         info = counter_arch_bp(bp[i]);
 536                         dr7 |= encode_dr7(i, info->len, info->type);
 537                 }
 538         }
 539
 540         return dr7;
 541 }
 542
 543 static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
 544                                         int len, int type, bool disabled)
 545 {
 546         int err, bp_len, bp_type;
 547
 548         err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
 549         if (!err) {
 550                 attr->bp_len = bp_len;
 551                 attr->bp_type = bp_type;
 552                 attr->disabled = disabled;
 553         }
 554
 555         return err;
 556 }
 557
 558 static struct perf_event *
 559 ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
 560                                 unsigned long addr, bool disabled)
 561 {
 562         struct perf_event_attr attr;
 563         int err;
 564
 565         ptrace_breakpoint_init(&attr);
 566         attr.bp_addr = addr;
 567
 568         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 569         if (err)
 570                 return ERR_PTR(err);
 571
 572         return register_user_hw_breakpoint(&attr, ptrace_triggered,
 573                                                  NULL, tsk);
 574 }
 575
 576 static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 577                                         int disabled)
 578 {
 579         struct perf_event_attr attr = bp->attr;
 580         int err;
 581
 582         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 583         if (err)
 584                 return err;
 585
 586         return modify_user_hw_breakpoint(bp, &attr);
 587 }
 588
 589 /*
 590  * Handle ptrace writes to debug register 7.
 591  */
 592 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 593 {
 594         struct thread_struct *thread = &tsk->thread;
 595         unsigned long old_dr7;
 596         bool second_pass = false;
 597         int i, rc, ret = 0;
 598
 599         data &= ~DR_CONTROL_RESERVED;
 600         old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 601
 602 restore:
 603         rc = 0;
 604         for (i = 0; i < HBP_NUM; i++) {
 605                 unsigned len, type;
 606                 bool disabled = !decode_dr7(data, i, &len, &type);
 607                 struct perf_event *bp = thread->ptrace_bps[i];
 608
 609                 if (!bp) {
 610                         if (disabled)
 611                                 continue;
 612
 613                         bp = ptrace_register_breakpoint(tsk,
 614                                         len, type, 0, disabled);
 615                         if (IS_ERR(bp)) {
 616                                 rc = PTR_ERR(bp);
 617                                 break;
 618                         }
 619
 620                         thread->ptrace_bps[i] = bp;
 621                         continue;
 622                 }
 623
 624                 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
 625                 if (rc)
 626                         break;
 627         }
 628
 629         /* Restore if the first pass failed, second_pass shouldn't fail. */
 630         if (rc && !WARN_ON(second_pass)) {
 631                 ret = rc;
 632                 data = old_dr7;
 633                 second_pass = true;
 634                 goto restore;
 635         }
 636
 637         return ret;
 638 }
 639
 640 /*
 641  * Handle PTRACE_PEEKUSR calls for the debug register area.
 642  */
 643 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 644 {
 645         struct thread_struct *thread = &tsk->thread;
 646         unsigned long val = 0;
 647         int index = n;
 648
 649         if (n < HBP_NUM) {
 650                 index = array_index_nospec(index, HBP_NUM);
 651                 struct perf_event *bp = thread->ptrace_bps[index];
 652
 653                 if (bp)
 654                         val = bp->hw.info.address;
 655         } else if (n == 6) {
 656                 val = thread->debugreg6;
 657         } else if (n == 7) {
 658                 val = thread->ptrace_dr7;
 659         }
 660         return val;
 661 }
 662
 663 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 664                                       unsigned long addr)
 665 {
 666         struct thread_struct *t = &tsk->thread;
 667         struct perf_event *bp = t->ptrace_bps[nr];
 668         int err = 0;
 669
 670         if (!bp) {
 671                 /*
 672                  * Put stub len and type to create an inactive but correct bp.
 673                  *
 674                  * CHECKME: the previous code returned -EIO if the addr wasn't
 675                  * a valid task virtual addr. The new one will return -EINVAL in
 676                  *  this case.
 677                  * -EINVAL may be what we want for in-kernel breakpoints users,
 678                  * but -EIO looks better for ptrace, since we refuse a register
 679                  * writing for the user. And anyway this is the previous
 680                  * behaviour.
 681                  */
 682                 bp = ptrace_register_breakpoint(tsk,
 683                                 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
 684                                 addr, true);
 685                 if (IS_ERR(bp))
 686                         err = PTR_ERR(bp);
 687                 else
 688                         t->ptrace_bps[nr] = bp;
 689         } else {
 690                 struct perf_event_attr attr = bp->attr;
 691
 692                 attr.bp_addr = addr;
 693                 err = modify_user_hw_breakpoint(bp, &attr);
 694         }
 695
 696         return err;
 697 }
 698
 699 /*
 700  * Handle PTRACE_POKEUSR calls for the debug register area.
 701  */
 702 static int ptrace_set_debugreg(struct task_struct *tsk, int n,
 703                                unsigned long val)
 704 {
 705         struct thread_struct *thread = &tsk->thread;
 706         /* There are no DR4 or DR5 registers */
 707         int rc = -EIO;
 708
 709         if (n < HBP_NUM) {
 710                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
 711         } else if (n == 6) {
 712                 thread->debugreg6 = val;
 713                 rc = 0;
 714         } else if (n == 7) {
 715                 rc = ptrace_write_dr7(tsk, val);
 716                 if (!rc)
 717                         thread->ptrace_dr7 = val;
 718         }
 719         return rc;
 720 }
 721
 722 /*
 723  * These access the current or another (stopped) task's io permission
 724  * bitmap for debugging or core dump.
 725  */
 726 static int ioperm_active(struct task_struct *target,
 727                          const struct user_regset *regset)
 728 {
 729         return target->thread.io_bitmap_max / regset->size;
 730 }
 731
 732 static int ioperm_get(struct task_struct *target,
 733                       const struct user_regset *regset,
 734                       unsigned int pos, unsigned int count,
 735                       void *kbuf, void __user *ubuf)
 736 {
 737         if (!target->thread.io_bitmap_ptr)
 738                 return -ENXIO;
 739
 740         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 741                                    target->thread.io_bitmap_ptr,
 742                                    0, IO_BITMAP_BYTES);
 743 }
 744
 745 /*
 746  * Called by kernel/ptrace.c when detaching..
 747  *
 748  * Make sure the single step bit is not set.
 749  */
 750 void ptrace_disable(struct task_struct *child)
 751 {
 752         user_disable_single_step(child);
 753 #ifdef TIF_SYSCALL_EMU
 754         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 755 #endif
 756 }
 757
 758 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 759 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 760 #endif
 761
 762 long arch_ptrace(struct task_struct *child, long request,
 763                  unsigned long addr, unsigned long data)
 764 {
 765         int ret;
 766         unsigned long __user *datap = (unsigned long __user *)data;
 767
 768         switch (request) {
 769         /* read the word at location addr in the USER area. */
 770         case PTRACE_PEEKUSR: {
 771                 unsigned long tmp;
 772
 773                 ret = -EIO;
 774                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 775                         break;
 776
 777                 tmp = 0;  /* Default return condition */
 778                 if (addr < sizeof(struct user_regs_struct))
 779                         tmp = getreg(child, addr);
 780                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 781                          addr <= offsetof(struct user, u_debugreg[7])) {
 782                         addr -= offsetof(struct user, u_debugreg[0]);
 783                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 784                 }
 785                 ret = put_user(tmp, datap);
 786                 break;
 787         }
 788
 789         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 790                 ret = -EIO;
 791                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 792                         break;
 793
 794                 if (addr < sizeof(struct user_regs_struct))
 795                         ret = putreg(child, addr, data);
 796                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 797                          addr <= offsetof(struct user, u_debugreg[7])) {
 798                         addr -= offsetof(struct user, u_debugreg[0]);
 799                         ret = ptrace_set_debugreg(child,
 800                                                   addr / sizeof(data), data);
 801                 }
 802                 break;
 803
 804         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 805                 return copy_regset_to_user(child,
 806                                            task_user_regset_view(current),
 807                                            REGSET_GENERAL,
 808                                            0, sizeof(struct user_regs_struct),
 809                                            datap);
 810
 811         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 812                 return copy_regset_from_user(child,
 813                                              task_user_regset_view(current),
 814                                              REGSET_GENERAL,
 815                                              0, sizeof(struct user_regs_struct),
 816                                              datap);
 817
 818         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 819                 return copy_regset_to_user(child,
 820                                            task_user_regset_view(current),
 821                                            REGSET_FP,
 822                                            0, sizeof(struct user_i387_struct),
 823                                            datap);
 824
 825         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 826                 return copy_regset_from_user(child,
 827                                              task_user_regset_view(current),
 828                                              REGSET_FP,
 829                                              0, sizeof(struct user_i387_struct),
 830                                              datap);
 831
 832 #ifdef CONFIG_X86_32
 833         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
 834                 return copy_regset_to_user(child, &user_x86_32_view,
 835                                            REGSET_XFP,
 836                                            0, sizeof(struct user_fxsr_struct),
 837                                            datap) ? -EIO : 0;
 838
 839         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
 840                 return copy_regset_from_user(child, &user_x86_32_view,
 841                                              REGSET_XFP,
 842                                              0, sizeof(struct user_fxsr_struct),
 843                                              datap) ? -EIO : 0;
 844 #endif
 845
 846 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 847         case PTRACE_GET_THREAD_AREA:
 848                 if ((int) addr < 0)
 849                         return -EIO;
 850                 ret = do_get_thread_area(child, addr,
 851                                         (struct user_desc __user *)data);
 852                 break;
 853
 854         case PTRACE_SET_THREAD_AREA:
 855                 if ((int) addr < 0)
 856                         return -EIO;
 857                 ret = do_set_thread_area(child, addr,
 858                                         (struct user_desc __user *)data, 0);
 859                 break;
 860 #endif
 861
 862 #ifdef CONFIG_X86_64
 863                 /* normal 64bit interface to access TLS data.
 864                    Works just like arch_prctl, except that the arguments
 865                    are reversed. */
 866         case PTRACE_ARCH_PRCTL:
 867                 ret = do_arch_prctl_64(child, data, addr);
 868                 break;
 869 #endif
 870
 871         default:
 872                 ret = ptrace_request(child, request, addr, data);
 873                 break;
 874         }
 875
 876         return ret;
 877 }
 878
 879 #ifdef CONFIG_IA32_EMULATION
 880
 881 #include <linux/compat.h>
 882 #include <linux/syscalls.h>
 883 #include <asm/ia32.h>
 884 #include <asm/user32.h>
 885
 886 #define R32(l,q)                                                        \
 887         case offsetof(struct user32, regs.l):                           \
 888                 regs->q = value; break
 889
 890 #define SEG32(rs)                                                       \
 891         case offsetof(struct user32, regs.rs):                          \
 892                 return set_segment_reg(child,                           \
 893                                        offsetof(struct user_regs_struct, rs), \
 894                                        value);                          \
 895                 break
 896
 897 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 898 {
 899         struct pt_regs *regs = task_pt_regs(child);
 900
 901         switch (regno) {
 902
 903         SEG32(cs);
 904         SEG32(ds);
 905         SEG32(es);
 906         SEG32(fs);
 907         SEG32(gs);
 908         SEG32(ss);
 909
 910         R32(ebx, bx);
 911         R32(ecx, cx);
 912         R32(edx, dx);
 913         R32(edi, di);
 914         R32(esi, si);
 915         R32(ebp, bp);
 916         R32(eax, ax);
 917         R32(eip, ip);
 918         R32(esp, sp);
 919
 920         case offsetof(struct user32, regs.orig_eax):
 921                 /*
 922                  * Warning: bizarre corner case fixup here.  A 32-bit
 923                  * debugger setting orig_eax to -1 wants to disable
 924                  * syscall restart.  Make sure that the syscall
 925                  * restart code sign-extends orig_ax.  Also make sure
 926                  * we interpret the -ERESTART* codes correctly if
 927                  * loaded into regs->ax in case the task is not
 928                  * actually still sitting at the exit from a 32-bit
 929                  * syscall with TS_COMPAT still set.
 930                  */
 931                 regs->orig_ax = value;
 932                 if (syscall_get_nr(child, regs) >= 0)
 933                         child->thread_info.status |= TS_I386_REGS_POKED;
 934                 break;
 935
 936         case offsetof(struct user32, regs.eflags):
 937                 return set_flags(child, value);
 938
 939         case offsetof(struct user32, u_debugreg[0]) ...
 940                 offsetof(struct user32, u_debugreg[7]):
 941                 regno -= offsetof(struct user32, u_debugreg[0]);
 942                 return ptrace_set_debugreg(child, regno / 4, value);
 943
 944         default:
 945                 if (regno > sizeof(struct user32) || (regno & 3))
 946                         return -EIO;
 947
 948                 /*
 949                  * Other dummy fields in the virtual user structure
 950                  * are ignored
 951                  */
 952                 break;
 953         }
 954         return 0;
 955 }
 956
 957 #undef R32
 958 #undef SEG32
 959
 960 #define R32(l,q)                                                        \
 961         case offsetof(struct user32, regs.l):                           \
 962                 *val = regs->q; break
 963
 964 #define SEG32(rs)                                                       \
 965         case offsetof(struct user32, regs.rs):                          \
 966                 *val = get_segment_reg(child,                           \
 967                                        offsetof(struct user_regs_struct, rs)); \
 968                 break
 969
 970 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 971 {
 972         struct pt_regs *regs = task_pt_regs(child);
 973
 974         switch (regno) {
 975
 976         SEG32(ds);
 977         SEG32(es);
 978         SEG32(fs);
 979         SEG32(gs);
 980
 981         R32(cs, cs);
 982         R32(ss, ss);
 983         R32(ebx, bx);
 984         R32(ecx, cx);
 985         R32(edx, dx);
 986         R32(edi, di);
 987         R32(esi, si);
 988         R32(ebp, bp);
 989         R32(eax, ax);
 990         R32(orig_eax, orig_ax);
 991         R32(eip, ip);
 992         R32(esp, sp);
 993
 994         case offsetof(struct user32, regs.eflags):
 995                 *val = get_flags(child);
 996                 break;
 997
 998         case offsetof(struct user32, u_debugreg[0]) ...
 999                 offsetof(struct user32, u_debugreg[7]):
1000                 regno -= offsetof(struct user32, u_debugreg[0]);
1001                 *val = ptrace_get_debugreg(child, regno / 4);
1002                 break;
1003
1004         default:
1005                 if (regno > sizeof(struct user32) || (regno & 3))
1006                         return -EIO;
1007
1008                 /*
1009                  * Other dummy fields in the virtual user structure
1010                  * are ignored
1011                  */
1012                 *val = 0;
1013                 break;
1014         }
1015         return 0;
1016 }
1017
1018 #undef R32
1019 #undef SEG32
1020
1021 static int genregs32_get(struct task_struct *target,
1022                          const struct user_regset *regset,
1023                          unsigned int pos, unsigned int count,
1024                          void *kbuf, void __user *ubuf)
1025 {
1026         if (kbuf) {
1027                 compat_ulong_t *k = kbuf;
1028                 while (count >= sizeof(*k)) {
1029                         getreg32(target, pos, k++);
1030                         count -= sizeof(*k);
1031                         pos += sizeof(*k);
1032                 }
1033         } else {
1034                 compat_ulong_t __user *u = ubuf;
1035                 while (count >= sizeof(*u)) {
1036                         compat_ulong_t word;
1037                         getreg32(target, pos, &word);
1038                         if (__put_user(word, u++))
1039                                 return -EFAULT;
1040                         count -= sizeof(*u);
1041                         pos += sizeof(*u);
1042                 }
1043         }
1044
1045         return 0;
1046 }
1047
1048 static int genregs32_set(struct task_struct *target,
1049                          const struct user_regset *regset,
1050                          unsigned int pos, unsigned int count,
1051                          const void *kbuf, const void __user *ubuf)
1052 {
1053         int ret = 0;
1054         if (kbuf) {
1055                 const compat_ulong_t *k = kbuf;
1056                 while (count >= sizeof(*k) && !ret) {
1057                         ret = putreg32(target, pos, *k++);
1058                         count -= sizeof(*k);
1059                         pos += sizeof(*k);
1060                 }
1061         } else {
1062                 const compat_ulong_t __user *u = ubuf;
1063                 while (count >= sizeof(*u) && !ret) {
1064                         compat_ulong_t word;
1065                         ret = __get_user(word, u++);
1066                         if (ret)
1067                                 break;
1068                         ret = putreg32(target, pos, word);
1069                         count -= sizeof(*u);
1070                         pos += sizeof(*u);
1071                 }
1072         }
1073         return ret;
1074 }
1075
1076 static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1077                              compat_ulong_t caddr, compat_ulong_t cdata)
1078 {
1079         unsigned long addr = caddr;
1080         unsigned long data = cdata;
1081         void __user *datap = compat_ptr(data);
1082         int ret;
1083         __u32 val;
1084
1085         switch (request) {
1086         case PTRACE_PEEKUSR:
1087                 ret = getreg32(child, addr, &val);
1088                 if (ret == 0)
1089                         ret = put_user(val, (__u32 __user *)datap);
1090                 break;
1091
1092         case PTRACE_POKEUSR:
1093                 ret = putreg32(child, addr, data);
1094                 break;
1095
1096         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1097                 return copy_regset_to_user(child, &user_x86_32_view,
1098                                            REGSET_GENERAL,
1099                                            0, sizeof(struct user_regs_struct32),
1100                                            datap);
1101
1102         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1103                 return copy_regset_from_user(child, &user_x86_32_view,
1104                                              REGSET_GENERAL, 0,
1105                                              sizeof(struct user_regs_struct32),
1106                                              datap);
1107
1108         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1109                 return copy_regset_to_user(child, &user_x86_32_view,
1110                                            REGSET_FP, 0,
1111                                            sizeof(struct user_i387_ia32_struct),
1112                                            datap);
1113
1114         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1115                 return copy_regset_from_user(
1116                         child, &user_x86_32_view, REGSET_FP,
1117                         0, sizeof(struct user_i387_ia32_struct), datap);
1118
1119         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1120                 return copy_regset_to_user(child, &user_x86_32_view,
1121                                            REGSET_XFP, 0,
1122                                            sizeof(struct user32_fxsr_struct),
1123                                            datap);
1124
1125         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1126                 return copy_regset_from_user(child, &user_x86_32_view,
1127                                              REGSET_XFP, 0,
1128                                              sizeof(struct user32_fxsr_struct),
1129                                              datap);
1130
1131         case PTRACE_GET_THREAD_AREA:
1132         case PTRACE_SET_THREAD_AREA:
1133                 return arch_ptrace(child, request, addr, data);
1134
1135         default:
1136                 return compat_ptrace_request(child, request, addr, data);
1137         }
1138
1139         return ret;
1140 }
1141 #endif /* CONFIG_IA32_EMULATION */
1142
1143 #ifdef CONFIG_X86_X32_ABI
1144 static long x32_arch_ptrace(struct task_struct *child,
1145                             compat_long_t request, compat_ulong_t caddr,
1146                             compat_ulong_t cdata)
1147 {
1148         unsigned long addr = caddr;
1149         unsigned long data = cdata;
1150         void __user *datap = compat_ptr(data);
1151         int ret;
1152
1153         switch (request) {
1154         /* Read 32bits at location addr in the USER area.  Only allow
1155            to return the lower 32bits of segment and debug registers.  */
1156         case PTRACE_PEEKUSR: {
1157                 u32 tmp;
1158
1159                 ret = -EIO;
1160                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1161                     addr < offsetof(struct user_regs_struct, cs))
1162                         break;
1163
1164                 tmp = 0;  /* Default return condition */
1165                 if (addr < sizeof(struct user_regs_struct))
1166                         tmp = getreg(child, addr);
1167                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1168                          addr <= offsetof(struct user, u_debugreg[7])) {
1169                         addr -= offsetof(struct user, u_debugreg[0]);
1170                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1171                 }
1172                 ret = put_user(tmp, (__u32 __user *)datap);
1173                 break;
1174         }
1175
1176         /* Write the word at location addr in the USER area.  Only allow
1177            to update segment and debug registers with the upper 32bits
1178            zero-extended. */
1179         case PTRACE_POKEUSR:
1180                 ret = -EIO;
1181                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1182                     addr < offsetof(struct user_regs_struct, cs))
1183                         break;
1184
1185                 if (addr < sizeof(struct user_regs_struct))
1186                         ret = putreg(child, addr, data);
1187                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1188                          addr <= offsetof(struct user, u_debugreg[7])) {
1189                         addr -= offsetof(struct user, u_debugreg[0]);
1190                         ret = ptrace_set_debugreg(child,
1191                                                   addr / sizeof(data), data);
1192                 }
1193                 break;
1194
1195         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1196                 return copy_regset_to_user(child,
1197                                            task_user_regset_view(current),
1198                                            REGSET_GENERAL,
1199                                            0, sizeof(struct user_regs_struct),
1200                                            datap);
1201
1202         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1203                 return copy_regset_from_user(child,
1204                                              task_user_regset_view(current),
1205                                              REGSET_GENERAL,
1206                                              0, sizeof(struct user_regs_struct),
1207                                              datap);
1208
1209         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1210                 return copy_regset_to_user(child,
1211                                            task_user_regset_view(current),
1212                                            REGSET_FP,
1213                                            0, sizeof(struct user_i387_struct),
1214                                            datap);
1215
1216         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1217                 return copy_regset_from_user(child,
1218                                              task_user_regset_view(current),
1219                                              REGSET_FP,
1220                                              0, sizeof(struct user_i387_struct),
1221                                              datap);
1222
1223         default:
1224                 return compat_ptrace_request(child, request, addr, data);
1225         }
1226
1227         return ret;
1228 }
1229 #endif
1230
1231 #ifdef CONFIG_COMPAT
1232 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1233                         compat_ulong_t caddr, compat_ulong_t cdata)
1234 {
1235 #ifdef CONFIG_X86_X32_ABI
1236         if (!in_ia32_syscall())
1237                 return x32_arch_ptrace(child, request, caddr, cdata);
1238 #endif
1239 #ifdef CONFIG_IA32_EMULATION
1240         return ia32_arch_ptrace(child, request, caddr, cdata);
1241 #else
1242         return 0;
1243 #endif
1244 }
1245 #endif  /* CONFIG_COMPAT */
1246
1247 #ifdef CONFIG_X86_64
1248
1249 static struct user_regset x86_64_regsets[] __ro_after_init = {
1250         [REGSET_GENERAL] = {
1251                 .core_note_type = NT_PRSTATUS,
1252                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1253                 .size = sizeof(long), .align = sizeof(long),
1254                 .get = genregs_get, .set = genregs_set
1255         },
1256         [REGSET_FP] = {
1257                 .core_note_type = NT_PRFPREG,
1258                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1259                 .size = sizeof(long), .align = sizeof(long),
1260                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1261         },
1262         [REGSET_XSTATE] = {
1263                 .core_note_type = NT_X86_XSTATE,
1264                 .size = sizeof(u64), .align = sizeof(u64),
1265                 .active = xstateregs_active, .get = xstateregs_get,
1266                 .set = xstateregs_set
1267         },
1268         [REGSET_IOPERM64] = {
1269                 .core_note_type = NT_386_IOPERM,
1270                 .n = IO_BITMAP_LONGS,
1271                 .size = sizeof(long), .align = sizeof(long),
1272                 .active = ioperm_active, .get = ioperm_get
1273         },
1274 };
1275
1276 static const struct user_regset_view user_x86_64_view = {
1277         .name = "x86_64", .e_machine = EM_X86_64,
1278         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1279 };
1280
1281 #else  /* CONFIG_X86_32 */
1282
1283 #define user_regs_struct32      user_regs_struct
1284 #define genregs32_get           genregs_get
1285 #define genregs32_set           genregs_set
1286
1287 #endif  /* CONFIG_X86_64 */
1288
1289 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1290 static struct user_regset x86_32_regsets[] __ro_after_init = {
1291         [REGSET_GENERAL] = {
1292                 .core_note_type = NT_PRSTATUS,
1293                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1294                 .size = sizeof(u32), .align = sizeof(u32),
1295                 .get = genregs32_get, .set = genregs32_set
1296         },
1297         [REGSET_FP] = {
1298                 .core_note_type = NT_PRFPREG,
1299                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1300                 .size = sizeof(u32), .align = sizeof(u32),
1301                 .active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1302         },
1303         [REGSET_XFP] = {
1304                 .core_note_type = NT_PRXFPREG,
1305                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1306                 .size = sizeof(u32), .align = sizeof(u32),
1307                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1308         },
1309         [REGSET_XSTATE] = {
1310                 .core_note_type = NT_X86_XSTATE,
1311                 .size = sizeof(u64), .align = sizeof(u64),
1312                 .active = xstateregs_active, .get = xstateregs_get,
1313                 .set = xstateregs_set
1314         },
1315         [REGSET_TLS] = {
1316                 .core_note_type = NT_386_TLS,
1317                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1318                 .size = sizeof(struct user_desc),
1319                 .align = sizeof(struct user_desc),
1320                 .active = regset_tls_active,
1321                 .get = regset_tls_get, .set = regset_tls_set
1322         },
1323         [REGSET_IOPERM32] = {
1324                 .core_note_type = NT_386_IOPERM,
1325                 .n = IO_BITMAP_BYTES / sizeof(u32),
1326                 .size = sizeof(u32), .align = sizeof(u32),
1327                 .active = ioperm_active, .get = ioperm_get
1328         },
1329 };
1330
1331 static const struct user_regset_view user_x86_32_view = {
1332         .name = "i386", .e_machine = EM_386,
1333         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1334 };
1335 #endif
1336
1337 /*
1338  * This represents bytes 464..511 in the memory layout exported through
1339  * the REGSET_XSTATE interface.
1340  */
1341 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1342
1343 void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1344 {
1345 #ifdef CONFIG_X86_64
1346         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1347 #endif
1348 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1349         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1350 #endif
1351         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1352 }
1353
1354 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1355 {
1356 #ifdef CONFIG_IA32_EMULATION
1357         if (!user_64bit_mode(task_pt_regs(task)))
1358 #endif
1359 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1360                 return &user_x86_32_view;
1361 #endif
1362 #ifdef CONFIG_X86_64
1363         return &user_x86_64_view;
1364 #endif
1365 }
1366
1367 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1368                                          int error_code, int si_code)
1369 {
1370         tsk->thread.trap_nr = X86_TRAP_DB;
1371         tsk->thread.error_code = error_code;
1372
1373         /* Send us the fake SIGTRAP */
1374         force_sig_fault(SIGTRAP, si_code,
1375                         user_mode(regs) ? (void __user *)regs->ip : NULL, tsk);
1376 }
1377
1378 void user_single_step_report(struct pt_regs *regs)
1379 {
1380         send_sigtrap(current, regs, 0, TRAP_BRKPT);
1381 }