arch/x86/kernel/ptrace.c

   1 /* By Ross Biro 1/23/92 */
   2 /*
   3  * Pentium III FXSR, SSE support
   4  *      Gareth Hughes <gareth@valinux.com>, May 2000
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/sched.h>
   9 #include <linux/mm.h>
  10 #include <linux/smp.h>
  11 #include <linux/errno.h>
  12 #include <linux/slab.h>
  13 #include <linux/ptrace.h>
  14 #include <linux/tracehook.h>
  15 #include <linux/user.h>
  16 #include <linux/elf.h>
  17 #include <linux/security.h>
  18 #include <linux/audit.h>
  19 #include <linux/seccomp.h>
  20 #include <linux/signal.h>
  21 #include <linux/perf_event.h>
  22 #include <linux/hw_breakpoint.h>
  23 #include <linux/rcupdate.h>
  24 #include <linux/export.h>
  25 #include <linux/context_tracking.h>
  26
  27 #include <asm/uaccess.h>
  28 #include <asm/pgtable.h>
  29 #include <asm/processor.h>
  30 #include <asm/fpu/internal.h>
  31 #include <asm/fpu/signal.h>
  32 #include <asm/fpu/regset.h>
  33 #include <asm/debugreg.h>
  34 #include <asm/ldt.h>
  35 #include <asm/desc.h>
  36 #include <asm/prctl.h>
  37 #include <asm/proto.h>
  38 #include <asm/hw_breakpoint.h>
  39 #include <asm/traps.h>
  40 #include <asm/syscall.h>
  41
  42 #include "tls.h"
  43
  44 enum x86_regset {
  45         REGSET_GENERAL,
  46         REGSET_FP,
  47         REGSET_XFP,
  48         REGSET_IOPERM64 = REGSET_XFP,
  49         REGSET_XSTATE,
  50         REGSET_TLS,
  51         REGSET_IOPERM32,
  52 };
  53
  54 struct pt_regs_offset {
  55         const char *name;
  56         int offset;
  57 };
  58
  59 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  60 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  61
  62 static const struct pt_regs_offset regoffset_table[] = {
  63 #ifdef CONFIG_X86_64
  64         REG_OFFSET_NAME(r15),
  65         REG_OFFSET_NAME(r14),
  66         REG_OFFSET_NAME(r13),
  67         REG_OFFSET_NAME(r12),
  68         REG_OFFSET_NAME(r11),
  69         REG_OFFSET_NAME(r10),
  70         REG_OFFSET_NAME(r9),
  71         REG_OFFSET_NAME(r8),
  72 #endif
  73         REG_OFFSET_NAME(bx),
  74         REG_OFFSET_NAME(cx),
  75         REG_OFFSET_NAME(dx),
  76         REG_OFFSET_NAME(si),
  77         REG_OFFSET_NAME(di),
  78         REG_OFFSET_NAME(bp),
  79         REG_OFFSET_NAME(ax),
  80 #ifdef CONFIG_X86_32
  81         REG_OFFSET_NAME(ds),
  82         REG_OFFSET_NAME(es),
  83         REG_OFFSET_NAME(fs),
  84         REG_OFFSET_NAME(gs),
  85 #endif
  86         REG_OFFSET_NAME(orig_ax),
  87         REG_OFFSET_NAME(ip),
  88         REG_OFFSET_NAME(cs),
  89         REG_OFFSET_NAME(flags),
  90         REG_OFFSET_NAME(sp),
  91         REG_OFFSET_NAME(ss),
  92         REG_OFFSET_END,
  93 };
  94
  95 /**
  96  * regs_query_register_offset() - query register offset from its name
  97  * @name:       the name of a register
  98  *
  99  * regs_query_register_offset() returns the offset of a register in struct
 100  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 101  */
 102 int regs_query_register_offset(const char *name)
 103 {
 104         const struct pt_regs_offset *roff;
 105         for (roff = regoffset_table; roff->name != NULL; roff++)
 106                 if (!strcmp(roff->name, name))
 107                         return roff->offset;
 108         return -EINVAL;
 109 }
 110
 111 /**
 112  * regs_query_register_name() - query register name from its offset
 113  * @offset:     the offset of a register in struct pt_regs.
 114  *
 115  * regs_query_register_name() returns the name of a register from its
 116  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 117  */
 118 const char *regs_query_register_name(unsigned int offset)
 119 {
 120         const struct pt_regs_offset *roff;
 121         for (roff = regoffset_table; roff->name != NULL; roff++)
 122                 if (roff->offset == offset)
 123                         return roff->name;
 124         return NULL;
 125 }
 126
 127 /*
 128  * does not yet catch signals sent when the child dies.
 129  * in exit.c or in signal.c.
 130  */
 131
 132 /*
 133  * Determines which flags the user has access to [1 = access, 0 = no access].
 134  */
 135 #define FLAG_MASK_32            ((unsigned long)                        \
 136                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
 137                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
 138                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
 139                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
 140                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
 141
 142 /*
 143  * Determines whether a value may be installed in a segment register.
 144  */
 145 static inline bool invalid_selector(u16 value)
 146 {
 147         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
 148 }
 149
 150 #ifdef CONFIG_X86_32
 151
 152 #define FLAG_MASK               FLAG_MASK_32
 153
 154 /*
 155  * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
 156  * when it traps.  The previous stack will be directly underneath the saved
 157  * registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
 158  *
 159  * Now, if the stack is empty, '&regs->sp' is out of range. In this
 160  * case we try to take the previous stack. To always return a non-null
 161  * stack pointer we fall back to regs as stack if no previous stack
 162  * exists.
 163  *
 164  * This is valid only for kernel mode traps.
 165  */
 166 unsigned long kernel_stack_pointer(struct pt_regs *regs)
 167 {
 168         unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
 169         unsigned long sp = (unsigned long)&regs->sp;
 170         u32 *prev_esp;
 171
 172         if (context == (sp & ~(THREAD_SIZE - 1)))
 173                 return sp;
 174
 175         prev_esp = (u32 *)(context);
 176         if (prev_esp)
 177                 return (unsigned long)prev_esp;
 178
 179         return (unsigned long)regs;
 180 }
 181 EXPORT_SYMBOL_GPL(kernel_stack_pointer);
 182
 183 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 184 {
 185         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 186         return &regs->bx + (regno >> 2);
 187 }
 188
 189 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 190 {
 191         /*
 192          * Returning the value truncates it to 16 bits.
 193          */
 194         unsigned int retval;
 195         if (offset != offsetof(struct user_regs_struct, gs))
 196                 retval = *pt_regs_access(task_pt_regs(task), offset);
 197         else {
 198                 if (task == current)
 199                         retval = get_user_gs(task_pt_regs(task));
 200                 else
 201                         retval = task_user_gs(task);
 202         }
 203         return retval;
 204 }
 205
 206 static int set_segment_reg(struct task_struct *task,
 207                            unsigned long offset, u16 value)
 208 {
 209         /*
 210          * The value argument was already truncated to 16 bits.
 211          */
 212         if (invalid_selector(value))
 213                 return -EIO;
 214
 215         /*
 216          * For %cs and %ss we cannot permit a null selector.
 217          * We can permit a bogus selector as long as it has USER_RPL.
 218          * Null selectors are fine for other segment registers, but
 219          * we will never get back to user mode with invalid %cs or %ss
 220          * and will take the trap in iret instead.  Much code relies
 221          * on user_mode() to distinguish a user trap frame (which can
 222          * safely use invalid selectors) from a kernel trap frame.
 223          */
 224         switch (offset) {
 225         case offsetof(struct user_regs_struct, cs):
 226         case offsetof(struct user_regs_struct, ss):
 227                 if (unlikely(value == 0))
 228                         return -EIO;
 229
 230         default:
 231                 *pt_regs_access(task_pt_regs(task), offset) = value;
 232                 break;
 233
 234         case offsetof(struct user_regs_struct, gs):
 235                 if (task == current)
 236                         set_user_gs(task_pt_regs(task), value);
 237                 else
 238                         task_user_gs(task) = value;
 239         }
 240
 241         return 0;
 242 }
 243
 244 #else  /* CONFIG_X86_64 */
 245
 246 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
 247
 248 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 249 {
 250         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 251         return &regs->r15 + (offset / sizeof(regs->r15));
 252 }
 253
 254 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 255 {
 256         /*
 257          * Returning the value truncates it to 16 bits.
 258          */
 259         unsigned int seg;
 260
 261         switch (offset) {
 262         case offsetof(struct user_regs_struct, fs):
 263                 if (task == current) {
 264                         /* Older gas can't assemble movq %?s,%r?? */
 265                         asm("movl %%fs,%0" : "=r" (seg));
 266                         return seg;
 267                 }
 268                 return task->thread.fsindex;
 269         case offsetof(struct user_regs_struct, gs):
 270                 if (task == current) {
 271                         asm("movl %%gs,%0" : "=r" (seg));
 272                         return seg;
 273                 }
 274                 return task->thread.gsindex;
 275         case offsetof(struct user_regs_struct, ds):
 276                 if (task == current) {
 277                         asm("movl %%ds,%0" : "=r" (seg));
 278                         return seg;
 279                 }
 280                 return task->thread.ds;
 281         case offsetof(struct user_regs_struct, es):
 282                 if (task == current) {
 283                         asm("movl %%es,%0" : "=r" (seg));
 284                         return seg;
 285                 }
 286                 return task->thread.es;
 287
 288         case offsetof(struct user_regs_struct, cs):
 289         case offsetof(struct user_regs_struct, ss):
 290                 break;
 291         }
 292         return *pt_regs_access(task_pt_regs(task), offset);
 293 }
 294
 295 static int set_segment_reg(struct task_struct *task,
 296                            unsigned long offset, u16 value)
 297 {
 298         /*
 299          * The value argument was already truncated to 16 bits.
 300          */
 301         if (invalid_selector(value))
 302                 return -EIO;
 303
 304         switch (offset) {
 305         case offsetof(struct user_regs_struct,fs):
 306                 /*
 307                  * If this is setting fs as for normal 64-bit use but
 308                  * setting fs_base has implicitly changed it, leave it.
 309                  */
 310                 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
 311                      task->thread.fs != 0) ||
 312                     (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
 313                      task->thread.fs == 0))
 314                         break;
 315                 task->thread.fsindex = value;
 316                 if (task == current)
 317                         loadsegment(fs, task->thread.fsindex);
 318                 break;
 319         case offsetof(struct user_regs_struct,gs):
 320                 /*
 321                  * If this is setting gs as for normal 64-bit use but
 322                  * setting gs_base has implicitly changed it, leave it.
 323                  */
 324                 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
 325                      task->thread.gs != 0) ||
 326                     (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
 327                      task->thread.gs == 0))
 328                         break;
 329                 task->thread.gsindex = value;
 330                 if (task == current)
 331                         load_gs_index(task->thread.gsindex);
 332                 break;
 333         case offsetof(struct user_regs_struct,ds):
 334                 task->thread.ds = value;
 335                 if (task == current)
 336                         loadsegment(ds, task->thread.ds);
 337                 break;
 338         case offsetof(struct user_regs_struct,es):
 339                 task->thread.es = value;
 340                 if (task == current)
 341                         loadsegment(es, task->thread.es);
 342                 break;
 343
 344                 /*
 345                  * Can't actually change these in 64-bit mode.
 346                  */
 347         case offsetof(struct user_regs_struct,cs):
 348                 if (unlikely(value == 0))
 349                         return -EIO;
 350                 task_pt_regs(task)->cs = value;
 351                 break;
 352         case offsetof(struct user_regs_struct,ss):
 353                 if (unlikely(value == 0))
 354                         return -EIO;
 355                 task_pt_regs(task)->ss = value;
 356                 break;
 357         }
 358
 359         return 0;
 360 }
 361
 362 #endif  /* CONFIG_X86_32 */
 363
 364 static unsigned long get_flags(struct task_struct *task)
 365 {
 366         unsigned long retval = task_pt_regs(task)->flags;
 367
 368         /*
 369          * If the debugger set TF, hide it from the readout.
 370          */
 371         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 372                 retval &= ~X86_EFLAGS_TF;
 373
 374         return retval;
 375 }
 376
 377 static int set_flags(struct task_struct *task, unsigned long value)
 378 {
 379         struct pt_regs *regs = task_pt_regs(task);
 380
 381         /*
 382          * If the user value contains TF, mark that
 383          * it was not "us" (the debugger) that set it.
 384          * If not, make sure it stays set if we had.
 385          */
 386         if (value & X86_EFLAGS_TF)
 387                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
 388         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 389                 value |= X86_EFLAGS_TF;
 390
 391         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 392
 393         return 0;
 394 }
 395
 396 static int putreg(struct task_struct *child,
 397                   unsigned long offset, unsigned long value)
 398 {
 399         switch (offset) {
 400         case offsetof(struct user_regs_struct, cs):
 401         case offsetof(struct user_regs_struct, ds):
 402         case offsetof(struct user_regs_struct, es):
 403         case offsetof(struct user_regs_struct, fs):
 404         case offsetof(struct user_regs_struct, gs):
 405         case offsetof(struct user_regs_struct, ss):
 406                 return set_segment_reg(child, offset, value);
 407
 408         case offsetof(struct user_regs_struct, flags):
 409                 return set_flags(child, value);
 410
 411 #ifdef CONFIG_X86_64
 412         case offsetof(struct user_regs_struct,fs_base):
 413                 if (value >= TASK_SIZE_OF(child))
 414                         return -EIO;
 415                 /*
 416                  * When changing the segment base, use do_arch_prctl
 417                  * to set either thread.fs or thread.fsindex and the
 418                  * corresponding GDT slot.
 419                  */
 420                 if (child->thread.fs != value)
 421                         return do_arch_prctl(child, ARCH_SET_FS, value);
 422                 return 0;
 423         case offsetof(struct user_regs_struct,gs_base):
 424                 /*
 425                  * Exactly the same here as the %fs handling above.
 426                  */
 427                 if (value >= TASK_SIZE_OF(child))
 428                         return -EIO;
 429                 if (child->thread.gs != value)
 430                         return do_arch_prctl(child, ARCH_SET_GS, value);
 431                 return 0;
 432 #endif
 433         }
 434
 435         *pt_regs_access(task_pt_regs(child), offset) = value;
 436         return 0;
 437 }
 438
 439 static unsigned long getreg(struct task_struct *task, unsigned long offset)
 440 {
 441         switch (offset) {
 442         case offsetof(struct user_regs_struct, cs):
 443         case offsetof(struct user_regs_struct, ds):
 444         case offsetof(struct user_regs_struct, es):
 445         case offsetof(struct user_regs_struct, fs):
 446         case offsetof(struct user_regs_struct, gs):
 447         case offsetof(struct user_regs_struct, ss):
 448                 return get_segment_reg(task, offset);
 449
 450         case offsetof(struct user_regs_struct, flags):
 451                 return get_flags(task);
 452
 453 #ifdef CONFIG_X86_64
 454         case offsetof(struct user_regs_struct, fs_base): {
 455                 /*
 456                  * do_arch_prctl may have used a GDT slot instead of
 457                  * the MSR.  To userland, it appears the same either
 458                  * way, except the %fs segment selector might not be 0.
 459                  */
 460                 unsigned int seg = task->thread.fsindex;
 461                 if (task->thread.fs != 0)
 462                         return task->thread.fs;
 463                 if (task == current)
 464                         asm("movl %%fs,%0" : "=r" (seg));
 465                 if (seg != FS_TLS_SEL)
 466                         return 0;
 467                 return get_desc_base(&task->thread.tls_array[FS_TLS]);
 468         }
 469         case offsetof(struct user_regs_struct, gs_base): {
 470                 /*
 471                  * Exactly the same here as the %fs handling above.
 472                  */
 473                 unsigned int seg = task->thread.gsindex;
 474                 if (task->thread.gs != 0)
 475                         return task->thread.gs;
 476                 if (task == current)
 477                         asm("movl %%gs,%0" : "=r" (seg));
 478                 if (seg != GS_TLS_SEL)
 479                         return 0;
 480                 return get_desc_base(&task->thread.tls_array[GS_TLS]);
 481         }
 482 #endif
 483         }
 484
 485         return *pt_regs_access(task_pt_regs(task), offset);
 486 }
 487
 488 static int genregs_get(struct task_struct *target,
 489                        const struct user_regset *regset,
 490                        unsigned int pos, unsigned int count,
 491                        void *kbuf, void __user *ubuf)
 492 {
 493         if (kbuf) {
 494                 unsigned long *k = kbuf;
 495                 while (count >= sizeof(*k)) {
 496                         *k++ = getreg(target, pos);
 497                         count -= sizeof(*k);
 498                         pos += sizeof(*k);
 499                 }
 500         } else {
 501                 unsigned long __user *u = ubuf;
 502                 while (count >= sizeof(*u)) {
 503                         if (__put_user(getreg(target, pos), u++))
 504                                 return -EFAULT;
 505                         count -= sizeof(*u);
 506                         pos += sizeof(*u);
 507                 }
 508         }
 509
 510         return 0;
 511 }
 512
 513 static int genregs_set(struct task_struct *target,
 514                        const struct user_regset *regset,
 515                        unsigned int pos, unsigned int count,
 516                        const void *kbuf, const void __user *ubuf)
 517 {
 518         int ret = 0;
 519         if (kbuf) {
 520                 const unsigned long *k = kbuf;
 521                 while (count >= sizeof(*k) && !ret) {
 522                         ret = putreg(target, pos, *k++);
 523                         count -= sizeof(*k);
 524                         pos += sizeof(*k);
 525                 }
 526         } else {
 527                 const unsigned long  __user *u = ubuf;
 528                 while (count >= sizeof(*u) && !ret) {
 529                         unsigned long word;
 530                         ret = __get_user(word, u++);
 531                         if (ret)
 532                                 break;
 533                         ret = putreg(target, pos, word);
 534                         count -= sizeof(*u);
 535                         pos += sizeof(*u);
 536                 }
 537         }
 538         return ret;
 539 }
 540
 541 static void ptrace_triggered(struct perf_event *bp,
 542                              struct perf_sample_data *data,
 543                              struct pt_regs *regs)
 544 {
 545         int i;
 546         struct thread_struct *thread = &(current->thread);
 547
 548         /*
 549          * Store in the virtual DR6 register the fact that the breakpoint
 550          * was hit so the thread's debugger will see it.
 551          */
 552         for (i = 0; i < HBP_NUM; i++) {
 553                 if (thread->ptrace_bps[i] == bp)
 554                         break;
 555         }
 556
 557         thread->debugreg6 |= (DR_TRAP0 << i);
 558 }
 559
 560 /*
 561  * Walk through every ptrace breakpoints for this thread and
 562  * build the dr7 value on top of their attributes.
 563  *
 564  */
 565 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 566 {
 567         int i;
 568         int dr7 = 0;
 569         struct arch_hw_breakpoint *info;
 570
 571         for (i = 0; i < HBP_NUM; i++) {
 572                 if (bp[i] && !bp[i]->attr.disabled) {
 573                         info = counter_arch_bp(bp[i]);
 574                         dr7 |= encode_dr7(i, info->len, info->type);
 575                 }
 576         }
 577
 578         return dr7;
 579 }
 580
 581 static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
 582                                         int len, int type, bool disabled)
 583 {
 584         int err, bp_len, bp_type;
 585
 586         err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
 587         if (!err) {
 588                 attr->bp_len = bp_len;
 589                 attr->bp_type = bp_type;
 590                 attr->disabled = disabled;
 591         }
 592
 593         return err;
 594 }
 595
 596 static struct perf_event *
 597 ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
 598                                 unsigned long addr, bool disabled)
 599 {
 600         struct perf_event_attr attr;
 601         int err;
 602
 603         ptrace_breakpoint_init(&attr);
 604         attr.bp_addr = addr;
 605
 606         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 607         if (err)
 608                 return ERR_PTR(err);
 609
 610         return register_user_hw_breakpoint(&attr, ptrace_triggered,
 611                                                  NULL, tsk);
 612 }
 613
 614 static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 615                                         int disabled)
 616 {
 617         struct perf_event_attr attr = bp->attr;
 618         int err;
 619
 620         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 621         if (err)
 622                 return err;
 623
 624         return modify_user_hw_breakpoint(bp, &attr);
 625 }
 626
 627 /*
 628  * Handle ptrace writes to debug register 7.
 629  */
 630 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 631 {
 632         struct thread_struct *thread = &tsk->thread;
 633         unsigned long old_dr7;
 634         bool second_pass = false;
 635         int i, rc, ret = 0;
 636
 637         data &= ~DR_CONTROL_RESERVED;
 638         old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 639
 640 restore:
 641         rc = 0;
 642         for (i = 0; i < HBP_NUM; i++) {
 643                 unsigned len, type;
 644                 bool disabled = !decode_dr7(data, i, &len, &type);
 645                 struct perf_event *bp = thread->ptrace_bps[i];
 646
 647                 if (!bp) {
 648                         if (disabled)
 649                                 continue;
 650
 651                         bp = ptrace_register_breakpoint(tsk,
 652                                         len, type, 0, disabled);
 653                         if (IS_ERR(bp)) {
 654                                 rc = PTR_ERR(bp);
 655                                 break;
 656                         }
 657
 658                         thread->ptrace_bps[i] = bp;
 659                         continue;
 660                 }
 661
 662                 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
 663                 if (rc)
 664                         break;
 665         }
 666
 667         /* Restore if the first pass failed, second_pass shouldn't fail. */
 668         if (rc && !WARN_ON(second_pass)) {
 669                 ret = rc;
 670                 data = old_dr7;
 671                 second_pass = true;
 672                 goto restore;
 673         }
 674
 675         return ret;
 676 }
 677
 678 /*
 679  * Handle PTRACE_PEEKUSR calls for the debug register area.
 680  */
 681 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 682 {
 683         struct thread_struct *thread = &tsk->thread;
 684         unsigned long val = 0;
 685
 686         if (n < HBP_NUM) {
 687                 struct perf_event *bp = thread->ptrace_bps[n];
 688
 689                 if (bp)
 690                         val = bp->hw.info.address;
 691         } else if (n == 6) {
 692                 val = thread->debugreg6;
 693         } else if (n == 7) {
 694                 val = thread->ptrace_dr7;
 695         }
 696         return val;
 697 }
 698
 699 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 700                                       unsigned long addr)
 701 {
 702         struct thread_struct *t = &tsk->thread;
 703         struct perf_event *bp = t->ptrace_bps[nr];
 704         int err = 0;
 705
 706         if (!bp) {
 707                 /*
 708                  * Put stub len and type to create an inactive but correct bp.
 709                  *
 710                  * CHECKME: the previous code returned -EIO if the addr wasn't
 711                  * a valid task virtual addr. The new one will return -EINVAL in
 712                  *  this case.
 713                  * -EINVAL may be what we want for in-kernel breakpoints users,
 714                  * but -EIO looks better for ptrace, since we refuse a register
 715                  * writing for the user. And anyway this is the previous
 716                  * behaviour.
 717                  */
 718                 bp = ptrace_register_breakpoint(tsk,
 719                                 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
 720                                 addr, true);
 721                 if (IS_ERR(bp))
 722                         err = PTR_ERR(bp);
 723                 else
 724                         t->ptrace_bps[nr] = bp;
 725         } else {
 726                 struct perf_event_attr attr = bp->attr;
 727
 728                 attr.bp_addr = addr;
 729                 err = modify_user_hw_breakpoint(bp, &attr);
 730         }
 731
 732         return err;
 733 }
 734
 735 /*
 736  * Handle PTRACE_POKEUSR calls for the debug register area.
 737  */
 738 static int ptrace_set_debugreg(struct task_struct *tsk, int n,
 739                                unsigned long val)
 740 {
 741         struct thread_struct *thread = &tsk->thread;
 742         /* There are no DR4 or DR5 registers */
 743         int rc = -EIO;
 744
 745         if (n < HBP_NUM) {
 746                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
 747         } else if (n == 6) {
 748                 thread->debugreg6 = val;
 749                 rc = 0;
 750         } else if (n == 7) {
 751                 rc = ptrace_write_dr7(tsk, val);
 752                 if (!rc)
 753                         thread->ptrace_dr7 = val;
 754         }
 755         return rc;
 756 }
 757
 758 /*
 759  * These access the current or another (stopped) task's io permission
 760  * bitmap for debugging or core dump.
 761  */
 762 static int ioperm_active(struct task_struct *target,
 763                          const struct user_regset *regset)
 764 {
 765         return target->thread.io_bitmap_max / regset->size;
 766 }
 767
 768 static int ioperm_get(struct task_struct *target,
 769                       const struct user_regset *regset,
 770                       unsigned int pos, unsigned int count,
 771                       void *kbuf, void __user *ubuf)
 772 {
 773         if (!target->thread.io_bitmap_ptr)
 774                 return -ENXIO;
 775
 776         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 777                                    target->thread.io_bitmap_ptr,
 778                                    0, IO_BITMAP_BYTES);
 779 }
 780
 781 /*
 782  * Called by kernel/ptrace.c when detaching..
 783  *
 784  * Make sure the single step bit is not set.
 785  */
 786 void ptrace_disable(struct task_struct *child)
 787 {
 788         user_disable_single_step(child);
 789 #ifdef TIF_SYSCALL_EMU
 790         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 791 #endif
 792 }
 793
 794 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 795 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 796 #endif
 797
 798 long arch_ptrace(struct task_struct *child, long request,
 799                  unsigned long addr, unsigned long data)
 800 {
 801         int ret;
 802         unsigned long __user *datap = (unsigned long __user *)data;
 803
 804         switch (request) {
 805         /* read the word at location addr in the USER area. */
 806         case PTRACE_PEEKUSR: {
 807                 unsigned long tmp;
 808
 809                 ret = -EIO;
 810                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 811                         break;
 812
 813                 tmp = 0;  /* Default return condition */
 814                 if (addr < sizeof(struct user_regs_struct))
 815                         tmp = getreg(child, addr);
 816                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 817                          addr <= offsetof(struct user, u_debugreg[7])) {
 818                         addr -= offsetof(struct user, u_debugreg[0]);
 819                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 820                 }
 821                 ret = put_user(tmp, datap);
 822                 break;
 823         }
 824
 825         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 826                 ret = -EIO;
 827                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 828                         break;
 829
 830                 if (addr < sizeof(struct user_regs_struct))
 831                         ret = putreg(child, addr, data);
 832                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 833                          addr <= offsetof(struct user, u_debugreg[7])) {
 834                         addr -= offsetof(struct user, u_debugreg[0]);
 835                         ret = ptrace_set_debugreg(child,
 836                                                   addr / sizeof(data), data);
 837                 }
 838                 break;
 839
 840         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 841                 return copy_regset_to_user(child,
 842                                            task_user_regset_view(current),
 843                                            REGSET_GENERAL,
 844                                            0, sizeof(struct user_regs_struct),
 845                                            datap);
 846
 847         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 848                 return copy_regset_from_user(child,
 849                                              task_user_regset_view(current),
 850                                              REGSET_GENERAL,
 851                                              0, sizeof(struct user_regs_struct),
 852                                              datap);
 853
 854         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 855                 return copy_regset_to_user(child,
 856                                            task_user_regset_view(current),
 857                                            REGSET_FP,
 858                                            0, sizeof(struct user_i387_struct),
 859                                            datap);
 860
 861         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 862                 return copy_regset_from_user(child,
 863                                              task_user_regset_view(current),
 864                                              REGSET_FP,
 865                                              0, sizeof(struct user_i387_struct),
 866                                              datap);
 867
 868 #ifdef CONFIG_X86_32
 869         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
 870                 return copy_regset_to_user(child, &user_x86_32_view,
 871                                            REGSET_XFP,
 872                                            0, sizeof(struct user_fxsr_struct),
 873                                            datap) ? -EIO : 0;
 874
 875         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
 876                 return copy_regset_from_user(child, &user_x86_32_view,
 877                                              REGSET_XFP,
 878                                              0, sizeof(struct user_fxsr_struct),
 879                                              datap) ? -EIO : 0;
 880 #endif
 881
 882 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 883         case PTRACE_GET_THREAD_AREA:
 884                 if ((int) addr < 0)
 885                         return -EIO;
 886                 ret = do_get_thread_area(child, addr,
 887                                         (struct user_desc __user *)data);
 888                 break;
 889
 890         case PTRACE_SET_THREAD_AREA:
 891                 if ((int) addr < 0)
 892                         return -EIO;
 893                 ret = do_set_thread_area(child, addr,
 894                                         (struct user_desc __user *)data, 0);
 895                 break;
 896 #endif
 897
 898 #ifdef CONFIG_X86_64
 899                 /* normal 64bit interface to access TLS data.
 900                    Works just like arch_prctl, except that the arguments
 901                    are reversed. */
 902         case PTRACE_ARCH_PRCTL:
 903                 ret = do_arch_prctl(child, data, addr);
 904                 break;
 905 #endif
 906
 907         default:
 908                 ret = ptrace_request(child, request, addr, data);
 909                 break;
 910         }
 911
 912         return ret;
 913 }
 914
 915 #ifdef CONFIG_IA32_EMULATION
 916
 917 #include <linux/compat.h>
 918 #include <linux/syscalls.h>
 919 #include <asm/ia32.h>
 920 #include <asm/user32.h>
 921
 922 #define R32(l,q)                                                        \
 923         case offsetof(struct user32, regs.l):                           \
 924                 regs->q = value; break
 925
 926 #define SEG32(rs)                                                       \
 927         case offsetof(struct user32, regs.rs):                          \
 928                 return set_segment_reg(child,                           \
 929                                        offsetof(struct user_regs_struct, rs), \
 930                                        value);                          \
 931                 break
 932
 933 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 934 {
 935         struct pt_regs *regs = task_pt_regs(child);
 936
 937         switch (regno) {
 938
 939         SEG32(cs);
 940         SEG32(ds);
 941         SEG32(es);
 942         SEG32(fs);
 943         SEG32(gs);
 944         SEG32(ss);
 945
 946         R32(ebx, bx);
 947         R32(ecx, cx);
 948         R32(edx, dx);
 949         R32(edi, di);
 950         R32(esi, si);
 951         R32(ebp, bp);
 952         R32(eax, ax);
 953         R32(eip, ip);
 954         R32(esp, sp);
 955
 956         case offsetof(struct user32, regs.orig_eax):
 957                 /*
 958                  * A 32-bit debugger setting orig_eax means to restore
 959                  * the state of the task restarting a 32-bit syscall.
 960                  * Make sure we interpret the -ERESTART* codes correctly
 961                  * in case the task is not actually still sitting at the
 962                  * exit from a 32-bit syscall with TS_COMPAT still set.
 963                  */
 964                 regs->orig_ax = value;
 965                 if (syscall_get_nr(child, regs) >= 0)
 966                         task_thread_info(child)->status |= TS_COMPAT;
 967                 break;
 968
 969         case offsetof(struct user32, regs.eflags):
 970                 return set_flags(child, value);
 971
 972         case offsetof(struct user32, u_debugreg[0]) ...
 973                 offsetof(struct user32, u_debugreg[7]):
 974                 regno -= offsetof(struct user32, u_debugreg[0]);
 975                 return ptrace_set_debugreg(child, regno / 4, value);
 976
 977         default:
 978                 if (regno > sizeof(struct user32) || (regno & 3))
 979                         return -EIO;
 980
 981                 /*
 982                  * Other dummy fields in the virtual user structure
 983                  * are ignored
 984                  */
 985                 break;
 986         }
 987         return 0;
 988 }
 989
 990 #undef R32
 991 #undef SEG32
 992
 993 #define R32(l,q)                                                        \
 994         case offsetof(struct user32, regs.l):                           \
 995                 *val = regs->q; break
 996
 997 #define SEG32(rs)                                                       \
 998         case offsetof(struct user32, regs.rs):                          \
 999                 *val = get_segment_reg(child,                           \
1000                                        offsetof(struct user_regs_struct, rs)); \
1001                 break
1002
1003 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1004 {
1005         struct pt_regs *regs = task_pt_regs(child);
1006
1007         switch (regno) {
1008
1009         SEG32(ds);
1010         SEG32(es);
1011         SEG32(fs);
1012         SEG32(gs);
1013
1014         R32(cs, cs);
1015         R32(ss, ss);
1016         R32(ebx, bx);
1017         R32(ecx, cx);
1018         R32(edx, dx);
1019         R32(edi, di);
1020         R32(esi, si);
1021         R32(ebp, bp);
1022         R32(eax, ax);
1023         R32(orig_eax, orig_ax);
1024         R32(eip, ip);
1025         R32(esp, sp);
1026
1027         case offsetof(struct user32, regs.eflags):
1028                 *val = get_flags(child);
1029                 break;
1030
1031         case offsetof(struct user32, u_debugreg[0]) ...
1032                 offsetof(struct user32, u_debugreg[7]):
1033                 regno -= offsetof(struct user32, u_debugreg[0]);
1034                 *val = ptrace_get_debugreg(child, regno / 4);
1035                 break;
1036
1037         default:
1038                 if (regno > sizeof(struct user32) || (regno & 3))
1039                         return -EIO;
1040
1041                 /*
1042                  * Other dummy fields in the virtual user structure
1043                  * are ignored
1044                  */
1045                 *val = 0;
1046                 break;
1047         }
1048         return 0;
1049 }
1050
1051 #undef R32
1052 #undef SEG32
1053
1054 static int genregs32_get(struct task_struct *target,
1055                          const struct user_regset *regset,
1056                          unsigned int pos, unsigned int count,
1057                          void *kbuf, void __user *ubuf)
1058 {
1059         if (kbuf) {
1060                 compat_ulong_t *k = kbuf;
1061                 while (count >= sizeof(*k)) {
1062                         getreg32(target, pos, k++);
1063                         count -= sizeof(*k);
1064                         pos += sizeof(*k);
1065                 }
1066         } else {
1067                 compat_ulong_t __user *u = ubuf;
1068                 while (count >= sizeof(*u)) {
1069                         compat_ulong_t word;
1070                         getreg32(target, pos, &word);
1071                         if (__put_user(word, u++))
1072                                 return -EFAULT;
1073                         count -= sizeof(*u);
1074                         pos += sizeof(*u);
1075                 }
1076         }
1077
1078         return 0;
1079 }
1080
1081 static int genregs32_set(struct task_struct *target,
1082                          const struct user_regset *regset,
1083                          unsigned int pos, unsigned int count,
1084                          const void *kbuf, const void __user *ubuf)
1085 {
1086         int ret = 0;
1087         if (kbuf) {
1088                 const compat_ulong_t *k = kbuf;
1089                 while (count >= sizeof(*k) && !ret) {
1090                         ret = putreg32(target, pos, *k++);
1091                         count -= sizeof(*k);
1092                         pos += sizeof(*k);
1093                 }
1094         } else {
1095                 const compat_ulong_t __user *u = ubuf;
1096                 while (count >= sizeof(*u) && !ret) {
1097                         compat_ulong_t word;
1098                         ret = __get_user(word, u++);
1099                         if (ret)
1100                                 break;
1101                         ret = putreg32(target, pos, word);
1102                         count -= sizeof(*u);
1103                         pos += sizeof(*u);
1104                 }
1105         }
1106         return ret;
1107 }
1108
1109 static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1110                              compat_ulong_t caddr, compat_ulong_t cdata)
1111 {
1112         unsigned long addr = caddr;
1113         unsigned long data = cdata;
1114         void __user *datap = compat_ptr(data);
1115         int ret;
1116         __u32 val;
1117
1118         switch (request) {
1119         case PTRACE_PEEKUSR:
1120                 ret = getreg32(child, addr, &val);
1121                 if (ret == 0)
1122                         ret = put_user(val, (__u32 __user *)datap);
1123                 break;
1124
1125         case PTRACE_POKEUSR:
1126                 ret = putreg32(child, addr, data);
1127                 break;
1128
1129         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1130                 return copy_regset_to_user(child, &user_x86_32_view,
1131                                            REGSET_GENERAL,
1132                                            0, sizeof(struct user_regs_struct32),
1133                                            datap);
1134
1135         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1136                 return copy_regset_from_user(child, &user_x86_32_view,
1137                                              REGSET_GENERAL, 0,
1138                                              sizeof(struct user_regs_struct32),
1139                                              datap);
1140
1141         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1142                 return copy_regset_to_user(child, &user_x86_32_view,
1143                                            REGSET_FP, 0,
1144                                            sizeof(struct user_i387_ia32_struct),
1145                                            datap);
1146
1147         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1148                 return copy_regset_from_user(
1149                         child, &user_x86_32_view, REGSET_FP,
1150                         0, sizeof(struct user_i387_ia32_struct), datap);
1151
1152         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1153                 return copy_regset_to_user(child, &user_x86_32_view,
1154                                            REGSET_XFP, 0,
1155                                            sizeof(struct user32_fxsr_struct),
1156                                            datap);
1157
1158         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1159                 return copy_regset_from_user(child, &user_x86_32_view,
1160                                              REGSET_XFP, 0,
1161                                              sizeof(struct user32_fxsr_struct),
1162                                              datap);
1163
1164         case PTRACE_GET_THREAD_AREA:
1165         case PTRACE_SET_THREAD_AREA:
1166                 return arch_ptrace(child, request, addr, data);
1167
1168         default:
1169                 return compat_ptrace_request(child, request, addr, data);
1170         }
1171
1172         return ret;
1173 }
1174 #endif /* CONFIG_IA32_EMULATION */
1175
1176 #ifdef CONFIG_X86_X32_ABI
1177 static long x32_arch_ptrace(struct task_struct *child,
1178                             compat_long_t request, compat_ulong_t caddr,
1179                             compat_ulong_t cdata)
1180 {
1181         unsigned long addr = caddr;
1182         unsigned long data = cdata;
1183         void __user *datap = compat_ptr(data);
1184         int ret;
1185
1186         switch (request) {
1187         /* Read 32bits at location addr in the USER area.  Only allow
1188            to return the lower 32bits of segment and debug registers.  */
1189         case PTRACE_PEEKUSR: {
1190                 u32 tmp;
1191
1192                 ret = -EIO;
1193                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1194                     addr < offsetof(struct user_regs_struct, cs))
1195                         break;
1196
1197                 tmp = 0;  /* Default return condition */
1198                 if (addr < sizeof(struct user_regs_struct))
1199                         tmp = getreg(child, addr);
1200                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1201                          addr <= offsetof(struct user, u_debugreg[7])) {
1202                         addr -= offsetof(struct user, u_debugreg[0]);
1203                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1204                 }
1205                 ret = put_user(tmp, (__u32 __user *)datap);
1206                 break;
1207         }
1208
1209         /* Write the word at location addr in the USER area.  Only allow
1210            to update segment and debug registers with the upper 32bits
1211            zero-extended. */
1212         case PTRACE_POKEUSR:
1213                 ret = -EIO;
1214                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1215                     addr < offsetof(struct user_regs_struct, cs))
1216                         break;
1217
1218                 if (addr < sizeof(struct user_regs_struct))
1219                         ret = putreg(child, addr, data);
1220                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1221                          addr <= offsetof(struct user, u_debugreg[7])) {
1222                         addr -= offsetof(struct user, u_debugreg[0]);
1223                         ret = ptrace_set_debugreg(child,
1224                                                   addr / sizeof(data), data);
1225                 }
1226                 break;
1227
1228         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1229                 return copy_regset_to_user(child,
1230                                            task_user_regset_view(current),
1231                                            REGSET_GENERAL,
1232                                            0, sizeof(struct user_regs_struct),
1233                                            datap);
1234
1235         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1236                 return copy_regset_from_user(child,
1237                                              task_user_regset_view(current),
1238                                              REGSET_GENERAL,
1239                                              0, sizeof(struct user_regs_struct),
1240                                              datap);
1241
1242         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1243                 return copy_regset_to_user(child,
1244                                            task_user_regset_view(current),
1245                                            REGSET_FP,
1246                                            0, sizeof(struct user_i387_struct),
1247                                            datap);
1248
1249         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1250                 return copy_regset_from_user(child,
1251                                              task_user_regset_view(current),
1252                                              REGSET_FP,
1253                                              0, sizeof(struct user_i387_struct),
1254                                              datap);
1255
1256         default:
1257                 return compat_ptrace_request(child, request, addr, data);
1258         }
1259
1260         return ret;
1261 }
1262 #endif
1263
1264 #ifdef CONFIG_COMPAT
1265 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1266                         compat_ulong_t caddr, compat_ulong_t cdata)
1267 {
1268 #ifdef CONFIG_X86_X32_ABI
1269         if (!is_ia32_task())
1270                 return x32_arch_ptrace(child, request, caddr, cdata);
1271 #endif
1272 #ifdef CONFIG_IA32_EMULATION
1273         return ia32_arch_ptrace(child, request, caddr, cdata);
1274 #else
1275         return 0;
1276 #endif
1277 }
1278 #endif  /* CONFIG_COMPAT */
1279
1280 #ifdef CONFIG_X86_64
1281
1282 static struct user_regset x86_64_regsets[] __read_mostly = {
1283         [REGSET_GENERAL] = {
1284                 .core_note_type = NT_PRSTATUS,
1285                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1286                 .size = sizeof(long), .align = sizeof(long),
1287                 .get = genregs_get, .set = genregs_set
1288         },
1289         [REGSET_FP] = {
1290                 .core_note_type = NT_PRFPREG,
1291                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1292                 .size = sizeof(long), .align = sizeof(long),
1293                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1294         },
1295         [REGSET_XSTATE] = {
1296                 .core_note_type = NT_X86_XSTATE,
1297                 .size = sizeof(u64), .align = sizeof(u64),
1298                 .active = xstateregs_active, .get = xstateregs_get,
1299                 .set = xstateregs_set
1300         },
1301         [REGSET_IOPERM64] = {
1302                 .core_note_type = NT_386_IOPERM,
1303                 .n = IO_BITMAP_LONGS,
1304                 .size = sizeof(long), .align = sizeof(long),
1305                 .active = ioperm_active, .get = ioperm_get
1306         },
1307 };
1308
1309 static const struct user_regset_view user_x86_64_view = {
1310         .name = "x86_64", .e_machine = EM_X86_64,
1311         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1312 };
1313
1314 #else  /* CONFIG_X86_32 */
1315
1316 #define user_regs_struct32      user_regs_struct
1317 #define genregs32_get           genregs_get
1318 #define genregs32_set           genregs_set
1319
1320 #endif  /* CONFIG_X86_64 */
1321
1322 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1323 static struct user_regset x86_32_regsets[] __read_mostly = {
1324         [REGSET_GENERAL] = {
1325                 .core_note_type = NT_PRSTATUS,
1326                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1327                 .size = sizeof(u32), .align = sizeof(u32),
1328                 .get = genregs32_get, .set = genregs32_set
1329         },
1330         [REGSET_FP] = {
1331                 .core_note_type = NT_PRFPREG,
1332                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1333                 .size = sizeof(u32), .align = sizeof(u32),
1334                 .active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1335         },
1336         [REGSET_XFP] = {
1337                 .core_note_type = NT_PRXFPREG,
1338                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1339                 .size = sizeof(u32), .align = sizeof(u32),
1340                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1341         },
1342         [REGSET_XSTATE] = {
1343                 .core_note_type = NT_X86_XSTATE,
1344                 .size = sizeof(u64), .align = sizeof(u64),
1345                 .active = xstateregs_active, .get = xstateregs_get,
1346                 .set = xstateregs_set
1347         },
1348         [REGSET_TLS] = {
1349                 .core_note_type = NT_386_TLS,
1350                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1351                 .size = sizeof(struct user_desc),
1352                 .align = sizeof(struct user_desc),
1353                 .active = regset_tls_active,
1354                 .get = regset_tls_get, .set = regset_tls_set
1355         },
1356         [REGSET_IOPERM32] = {
1357                 .core_note_type = NT_386_IOPERM,
1358                 .n = IO_BITMAP_BYTES / sizeof(u32),
1359                 .size = sizeof(u32), .align = sizeof(u32),
1360                 .active = ioperm_active, .get = ioperm_get
1361         },
1362 };
1363
1364 static const struct user_regset_view user_x86_32_view = {
1365         .name = "i386", .e_machine = EM_386,
1366         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1367 };
1368 #endif
1369
1370 /*
1371  * This represents bytes 464..511 in the memory layout exported through
1372  * the REGSET_XSTATE interface.
1373  */
1374 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1375
1376 void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1377 {
1378 #ifdef CONFIG_X86_64
1379         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1380 #endif
1381 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1382         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1383 #endif
1384         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1385 }
1386
1387 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1388 {
1389 #ifdef CONFIG_IA32_EMULATION
1390         if (test_tsk_thread_flag(task, TIF_IA32))
1391 #endif
1392 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1393                 return &user_x86_32_view;
1394 #endif
1395 #ifdef CONFIG_X86_64
1396         return &user_x86_64_view;
1397 #endif
1398 }
1399
1400 static void fill_sigtrap_info(struct task_struct *tsk,
1401                                 struct pt_regs *regs,
1402                                 int error_code, int si_code,
1403                                 struct siginfo *info)
1404 {
1405         tsk->thread.trap_nr = X86_TRAP_DB;
1406         tsk->thread.error_code = error_code;
1407
1408         memset(info, 0, sizeof(*info));
1409         info->si_signo = SIGTRAP;
1410         info->si_code = si_code;
1411         info->si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
1412 }
1413
1414 void user_single_step_siginfo(struct task_struct *tsk,
1415                                 struct pt_regs *regs,
1416                                 struct siginfo *info)
1417 {
1418         fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1419 }
1420
1421 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1422                                          int error_code, int si_code)
1423 {
1424         struct siginfo info;
1425
1426         fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1427         /* Send us the fake SIGTRAP */
1428         force_sig_info(SIGTRAP, &info, tsk);
1429 }