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