kernel/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 static const int arg_offs_table[] = {
 128 #ifdef CONFIG_X86_32
 129         [0] = offsetof(struct pt_regs, ax),
 130         [1] = offsetof(struct pt_regs, dx),
 131         [2] = offsetof(struct pt_regs, cx)
 132 #else /* CONFIG_X86_64 */
 133         [0] = offsetof(struct pt_regs, di),
 134         [1] = offsetof(struct pt_regs, si),
 135         [2] = offsetof(struct pt_regs, dx),
 136         [3] = offsetof(struct pt_regs, cx),
 137         [4] = offsetof(struct pt_regs, r8),
 138         [5] = offsetof(struct pt_regs, r9)
 139 #endif
 140 };
 141
 142 /*
 143  * does not yet catch signals sent when the child dies.
 144  * in exit.c or in signal.c.
 145  */
 146
 147 /*
 148  * Determines which flags the user has access to [1 = access, 0 = no access].
 149  */
 150 #define FLAG_MASK_32            ((unsigned long)                        \
 151                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
 152                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
 153                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
 154                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
 155                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
 156
 157 /*
 158  * Determines whether a value may be installed in a segment register.
 159  */
 160 static inline bool invalid_selector(u16 value)
 161 {
 162         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
 163 }
 164
 165 #ifdef CONFIG_X86_32
 166
 167 #define FLAG_MASK               FLAG_MASK_32
 168
 169 /*
 170  * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
 171  * when it traps.  The previous stack will be directly underneath the saved
 172  * registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
 173  *
 174  * Now, if the stack is empty, '&regs->sp' is out of range. In this
 175  * case we try to take the previous stack. To always return a non-null
 176  * stack pointer we fall back to regs as stack if no previous stack
 177  * exists.
 178  *
 179  * This is valid only for kernel mode traps.
 180  */
 181 unsigned long kernel_stack_pointer(struct pt_regs *regs)
 182 {
 183         unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
 184         unsigned long sp = (unsigned long)&regs->sp;
 185         u32 *prev_esp;
 186
 187         if (context == (sp & ~(THREAD_SIZE - 1)))
 188                 return sp;
 189
 190         prev_esp = (u32 *)(context);
 191         if (prev_esp)
 192                 return (unsigned long)prev_esp;
 193
 194         return (unsigned long)regs;
 195 }
 196 EXPORT_SYMBOL_GPL(kernel_stack_pointer);
 197
 198 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 199 {
 200         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 201         return &regs->bx + (regno >> 2);
 202 }
 203
 204 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 205 {
 206         /*
 207          * Returning the value truncates it to 16 bits.
 208          */
 209         unsigned int retval;
 210         if (offset != offsetof(struct user_regs_struct, gs))
 211                 retval = *pt_regs_access(task_pt_regs(task), offset);
 212         else {
 213                 if (task == current)
 214                         retval = get_user_gs(task_pt_regs(task));
 215                 else
 216                         retval = task_user_gs(task);
 217         }
 218         return retval;
 219 }
 220
 221 static int set_segment_reg(struct task_struct *task,
 222                            unsigned long offset, u16 value)
 223 {
 224         /*
 225          * The value argument was already truncated to 16 bits.
 226          */
 227         if (invalid_selector(value))
 228                 return -EIO;
 229
 230         /*
 231          * For %cs and %ss we cannot permit a null selector.
 232          * We can permit a bogus selector as long as it has USER_RPL.
 233          * Null selectors are fine for other segment registers, but
 234          * we will never get back to user mode with invalid %cs or %ss
 235          * and will take the trap in iret instead.  Much code relies
 236          * on user_mode() to distinguish a user trap frame (which can
 237          * safely use invalid selectors) from a kernel trap frame.
 238          */
 239         switch (offset) {
 240         case offsetof(struct user_regs_struct, cs):
 241         case offsetof(struct user_regs_struct, ss):
 242                 if (unlikely(value == 0))
 243                         return -EIO;
 244
 245         default:
 246                 *pt_regs_access(task_pt_regs(task), offset) = value;
 247                 break;
 248
 249         case offsetof(struct user_regs_struct, gs):
 250                 if (task == current)
 251                         set_user_gs(task_pt_regs(task), value);
 252                 else
 253                         task_user_gs(task) = value;
 254         }
 255
 256         return 0;
 257 }
 258
 259 #else  /* CONFIG_X86_64 */
 260
 261 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
 262
 263 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 264 {
 265         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 266         return &regs->r15 + (offset / sizeof(regs->r15));
 267 }
 268
 269 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 270 {
 271         /*
 272          * Returning the value truncates it to 16 bits.
 273          */
 274         unsigned int seg;
 275
 276         switch (offset) {
 277         case offsetof(struct user_regs_struct, fs):
 278                 if (task == current) {
 279                         /* Older gas can't assemble movq %?s,%r?? */
 280                         asm("movl %%fs,%0" : "=r" (seg));
 281                         return seg;
 282                 }
 283                 return task->thread.fsindex;
 284         case offsetof(struct user_regs_struct, gs):
 285                 if (task == current) {
 286                         asm("movl %%gs,%0" : "=r" (seg));
 287                         return seg;
 288                 }
 289                 return task->thread.gsindex;
 290         case offsetof(struct user_regs_struct, ds):
 291                 if (task == current) {
 292                         asm("movl %%ds,%0" : "=r" (seg));
 293                         return seg;
 294                 }
 295                 return task->thread.ds;
 296         case offsetof(struct user_regs_struct, es):
 297                 if (task == current) {
 298                         asm("movl %%es,%0" : "=r" (seg));
 299                         return seg;
 300                 }
 301                 return task->thread.es;
 302
 303         case offsetof(struct user_regs_struct, cs):
 304         case offsetof(struct user_regs_struct, ss):
 305                 break;
 306         }
 307         return *pt_regs_access(task_pt_regs(task), offset);
 308 }
 309
 310 static int set_segment_reg(struct task_struct *task,
 311                            unsigned long offset, u16 value)
 312 {
 313         /*
 314          * The value argument was already truncated to 16 bits.
 315          */
 316         if (invalid_selector(value))
 317                 return -EIO;
 318
 319         switch (offset) {
 320         case offsetof(struct user_regs_struct,fs):
 321                 /*
 322                  * If this is setting fs as for normal 64-bit use but
 323                  * setting fs_base has implicitly changed it, leave it.
 324                  */
 325                 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
 326                      task->thread.fs != 0) ||
 327                     (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
 328                      task->thread.fs == 0))
 329                         break;
 330                 task->thread.fsindex = value;
 331                 if (task == current)
 332                         loadsegment(fs, task->thread.fsindex);
 333                 break;
 334         case offsetof(struct user_regs_struct,gs):
 335                 /*
 336                  * If this is setting gs as for normal 64-bit use but
 337                  * setting gs_base has implicitly changed it, leave it.
 338                  */
 339                 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
 340                      task->thread.gs != 0) ||
 341                     (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
 342                      task->thread.gs == 0))
 343                         break;
 344                 task->thread.gsindex = value;
 345                 if (task == current)
 346                         load_gs_index(task->thread.gsindex);
 347                 break;
 348         case offsetof(struct user_regs_struct,ds):
 349                 task->thread.ds = value;
 350                 if (task == current)
 351                         loadsegment(ds, task->thread.ds);
 352                 break;
 353         case offsetof(struct user_regs_struct,es):
 354                 task->thread.es = value;
 355                 if (task == current)
 356                         loadsegment(es, task->thread.es);
 357                 break;
 358
 359                 /*
 360                  * Can't actually change these in 64-bit mode.
 361                  */
 362         case offsetof(struct user_regs_struct,cs):
 363                 if (unlikely(value == 0))
 364                         return -EIO;
 365                 task_pt_regs(task)->cs = value;
 366                 break;
 367         case offsetof(struct user_regs_struct,ss):
 368                 if (unlikely(value == 0))
 369                         return -EIO;
 370                 task_pt_regs(task)->ss = value;
 371                 break;
 372         }
 373
 374         return 0;
 375 }
 376
 377 #endif  /* CONFIG_X86_32 */
 378
 379 static unsigned long get_flags(struct task_struct *task)
 380 {
 381         unsigned long retval = task_pt_regs(task)->flags;
 382
 383         /*
 384          * If the debugger set TF, hide it from the readout.
 385          */
 386         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 387                 retval &= ~X86_EFLAGS_TF;
 388
 389         return retval;
 390 }
 391
 392 static int set_flags(struct task_struct *task, unsigned long value)
 393 {
 394         struct pt_regs *regs = task_pt_regs(task);
 395
 396         /*
 397          * If the user value contains TF, mark that
 398          * it was not "us" (the debugger) that set it.
 399          * If not, make sure it stays set if we had.
 400          */
 401         if (value & X86_EFLAGS_TF)
 402                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
 403         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 404                 value |= X86_EFLAGS_TF;
 405
 406         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 407
 408         return 0;
 409 }
 410
 411 static int putreg(struct task_struct *child,
 412                   unsigned long offset, unsigned long value)
 413 {
 414         switch (offset) {
 415         case offsetof(struct user_regs_struct, cs):
 416         case offsetof(struct user_regs_struct, ds):
 417         case offsetof(struct user_regs_struct, es):
 418         case offsetof(struct user_regs_struct, fs):
 419         case offsetof(struct user_regs_struct, gs):
 420         case offsetof(struct user_regs_struct, ss):
 421                 return set_segment_reg(child, offset, value);
 422
 423         case offsetof(struct user_regs_struct, flags):
 424                 return set_flags(child, value);
 425
 426 #ifdef CONFIG_X86_64
 427         case offsetof(struct user_regs_struct,fs_base):
 428                 if (value >= TASK_SIZE_OF(child))
 429                         return -EIO;
 430                 /*
 431                  * When changing the segment base, use do_arch_prctl
 432                  * to set either thread.fs or thread.fsindex and the
 433                  * corresponding GDT slot.
 434                  */
 435                 if (child->thread.fs != value)
 436                         return do_arch_prctl(child, ARCH_SET_FS, value);
 437                 return 0;
 438         case offsetof(struct user_regs_struct,gs_base):
 439                 /*
 440                  * Exactly the same here as the %fs handling above.
 441                  */
 442                 if (value >= TASK_SIZE_OF(child))
 443                         return -EIO;
 444                 if (child->thread.gs != value)
 445                         return do_arch_prctl(child, ARCH_SET_GS, value);
 446                 return 0;
 447 #endif
 448         }
 449
 450         *pt_regs_access(task_pt_regs(child), offset) = value;
 451         return 0;
 452 }
 453
 454 static unsigned long getreg(struct task_struct *task, unsigned long offset)
 455 {
 456         switch (offset) {
 457         case offsetof(struct user_regs_struct, cs):
 458         case offsetof(struct user_regs_struct, ds):
 459         case offsetof(struct user_regs_struct, es):
 460         case offsetof(struct user_regs_struct, fs):
 461         case offsetof(struct user_regs_struct, gs):
 462         case offsetof(struct user_regs_struct, ss):
 463                 return get_segment_reg(task, offset);
 464
 465         case offsetof(struct user_regs_struct, flags):
 466                 return get_flags(task);
 467
 468 #ifdef CONFIG_X86_64
 469         case offsetof(struct user_regs_struct, fs_base): {
 470                 /*
 471                  * do_arch_prctl may have used a GDT slot instead of
 472                  * the MSR.  To userland, it appears the same either
 473                  * way, except the %fs segment selector might not be 0.
 474                  */
 475                 unsigned int seg = task->thread.fsindex;
 476                 if (task->thread.fs != 0)
 477                         return task->thread.fs;
 478                 if (task == current)
 479                         asm("movl %%fs,%0" : "=r" (seg));
 480                 if (seg != FS_TLS_SEL)
 481                         return 0;
 482                 return get_desc_base(&task->thread.tls_array[FS_TLS]);
 483         }
 484         case offsetof(struct user_regs_struct, gs_base): {
 485                 /*
 486                  * Exactly the same here as the %fs handling above.
 487                  */
 488                 unsigned int seg = task->thread.gsindex;
 489                 if (task->thread.gs != 0)
 490                         return task->thread.gs;
 491                 if (task == current)
 492                         asm("movl %%gs,%0" : "=r" (seg));
 493                 if (seg != GS_TLS_SEL)
 494                         return 0;
 495                 return get_desc_base(&task->thread.tls_array[GS_TLS]);
 496         }
 497 #endif
 498         }
 499
 500         return *pt_regs_access(task_pt_regs(task), offset);
 501 }
 502
 503 static int genregs_get(struct task_struct *target,
 504                        const struct user_regset *regset,
 505                        unsigned int pos, unsigned int count,
 506                        void *kbuf, void __user *ubuf)
 507 {
 508         if (kbuf) {
 509                 unsigned long *k = kbuf;
 510                 while (count >= sizeof(*k)) {
 511                         *k++ = getreg(target, pos);
 512                         count -= sizeof(*k);
 513                         pos += sizeof(*k);
 514                 }
 515         } else {
 516                 unsigned long __user *u = ubuf;
 517                 while (count >= sizeof(*u)) {
 518                         if (__put_user(getreg(target, pos), u++))
 519                                 return -EFAULT;
 520                         count -= sizeof(*u);
 521                         pos += sizeof(*u);
 522                 }
 523         }
 524
 525         return 0;
 526 }
 527
 528 static int genregs_set(struct task_struct *target,
 529                        const struct user_regset *regset,
 530                        unsigned int pos, unsigned int count,
 531                        const void *kbuf, const void __user *ubuf)
 532 {
 533         int ret = 0;
 534         if (kbuf) {
 535                 const unsigned long *k = kbuf;
 536                 while (count >= sizeof(*k) && !ret) {
 537                         ret = putreg(target, pos, *k++);
 538                         count -= sizeof(*k);
 539                         pos += sizeof(*k);
 540                 }
 541         } else {
 542                 const unsigned long  __user *u = ubuf;
 543                 while (count >= sizeof(*u) && !ret) {
 544                         unsigned long word;
 545                         ret = __get_user(word, u++);
 546                         if (ret)
 547                                 break;
 548                         ret = putreg(target, pos, word);
 549                         count -= sizeof(*u);
 550                         pos += sizeof(*u);
 551                 }
 552         }
 553         return ret;
 554 }
 555
 556 static void ptrace_triggered(struct perf_event *bp,
 557                              struct perf_sample_data *data,
 558                              struct pt_regs *regs)
 559 {
 560         int i;
 561         struct thread_struct *thread = &(current->thread);
 562
 563         /*
 564          * Store in the virtual DR6 register the fact that the breakpoint
 565          * was hit so the thread's debugger will see it.
 566          */
 567         for (i = 0; i < HBP_NUM; i++) {
 568                 if (thread->ptrace_bps[i] == bp)
 569                         break;
 570         }
 571
 572         thread->debugreg6 |= (DR_TRAP0 << i);
 573 }
 574
 575 /*
 576  * Walk through every ptrace breakpoints for this thread and
 577  * build the dr7 value on top of their attributes.
 578  *
 579  */
 580 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 581 {
 582         int i;
 583         int dr7 = 0;
 584         struct arch_hw_breakpoint *info;
 585
 586         for (i = 0; i < HBP_NUM; i++) {
 587                 if (bp[i] && !bp[i]->attr.disabled) {
 588                         info = counter_arch_bp(bp[i]);
 589                         dr7 |= encode_dr7(i, info->len, info->type);
 590                 }
 591         }
 592
 593         return dr7;
 594 }
 595
 596 static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
 597                                         int len, int type, bool disabled)
 598 {
 599         int err, bp_len, bp_type;
 600
 601         err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
 602         if (!err) {
 603                 attr->bp_len = bp_len;
 604                 attr->bp_type = bp_type;
 605                 attr->disabled = disabled;
 606         }
 607
 608         return err;
 609 }
 610
 611 static struct perf_event *
 612 ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
 613                                 unsigned long addr, bool disabled)
 614 {
 615         struct perf_event_attr attr;
 616         int err;
 617
 618         ptrace_breakpoint_init(&attr);
 619         attr.bp_addr = addr;
 620
 621         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 622         if (err)
 623                 return ERR_PTR(err);
 624
 625         return register_user_hw_breakpoint(&attr, ptrace_triggered,
 626                                                  NULL, tsk);
 627 }
 628
 629 static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 630                                         int disabled)
 631 {
 632         struct perf_event_attr attr = bp->attr;
 633         int err;
 634
 635         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 636         if (err)
 637                 return err;
 638
 639         return modify_user_hw_breakpoint(bp, &attr);
 640 }
 641
 642 /*
 643  * Handle ptrace writes to debug register 7.
 644  */
 645 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 646 {
 647         struct thread_struct *thread = &tsk->thread;
 648         unsigned long old_dr7;
 649         bool second_pass = false;
 650         int i, rc, ret = 0;
 651
 652         data &= ~DR_CONTROL_RESERVED;
 653         old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 654
 655 restore:
 656         rc = 0;
 657         for (i = 0; i < HBP_NUM; i++) {
 658                 unsigned len, type;
 659                 bool disabled = !decode_dr7(data, i, &len, &type);
 660                 struct perf_event *bp = thread->ptrace_bps[i];
 661
 662                 if (!bp) {
 663                         if (disabled)
 664                                 continue;
 665
 666                         bp = ptrace_register_breakpoint(tsk,
 667                                         len, type, 0, disabled);
 668                         if (IS_ERR(bp)) {
 669                                 rc = PTR_ERR(bp);
 670                                 break;
 671                         }
 672
 673                         thread->ptrace_bps[i] = bp;
 674                         continue;
 675                 }
 676
 677                 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
 678                 if (rc)
 679                         break;
 680         }
 681
 682         /* Restore if the first pass failed, second_pass shouldn't fail. */
 683         if (rc && !WARN_ON(second_pass)) {
 684                 ret = rc;
 685                 data = old_dr7;
 686                 second_pass = true;
 687                 goto restore;
 688         }
 689
 690         return ret;
 691 }
 692
 693 /*
 694  * Handle PTRACE_PEEKUSR calls for the debug register area.
 695  */
 696 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 697 {
 698         struct thread_struct *thread = &tsk->thread;
 699         unsigned long val = 0;
 700
 701         if (n < HBP_NUM) {
 702                 struct perf_event *bp = thread->ptrace_bps[n];
 703
 704                 if (bp)
 705                         val = bp->hw.info.address;
 706         } else if (n == 6) {
 707                 val = thread->debugreg6;
 708         } else if (n == 7) {
 709                 val = thread->ptrace_dr7;
 710         }
 711         return val;
 712 }
 713
 714 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 715                                       unsigned long addr)
 716 {
 717         struct thread_struct *t = &tsk->thread;
 718         struct perf_event *bp = t->ptrace_bps[nr];
 719         int err = 0;
 720
 721         if (!bp) {
 722                 /*
 723                  * Put stub len and type to create an inactive but correct bp.
 724                  *
 725                  * CHECKME: the previous code returned -EIO if the addr wasn't
 726                  * a valid task virtual addr. The new one will return -EINVAL in
 727                  *  this case.
 728                  * -EINVAL may be what we want for in-kernel breakpoints users,
 729                  * but -EIO looks better for ptrace, since we refuse a register
 730                  * writing for the user. And anyway this is the previous
 731                  * behaviour.
 732                  */
 733                 bp = ptrace_register_breakpoint(tsk,
 734                                 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
 735                                 addr, true);
 736                 if (IS_ERR(bp))
 737                         err = PTR_ERR(bp);
 738                 else
 739                         t->ptrace_bps[nr] = bp;
 740         } else {
 741                 struct perf_event_attr attr = bp->attr;
 742
 743                 attr.bp_addr = addr;
 744                 err = modify_user_hw_breakpoint(bp, &attr);
 745         }
 746
 747         return err;
 748 }
 749
 750 /*
 751  * Handle PTRACE_POKEUSR calls for the debug register area.
 752  */
 753 static int ptrace_set_debugreg(struct task_struct *tsk, int n,
 754                                unsigned long val)
 755 {
 756         struct thread_struct *thread = &tsk->thread;
 757         /* There are no DR4 or DR5 registers */
 758         int rc = -EIO;
 759
 760         if (n < HBP_NUM) {
 761                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
 762         } else if (n == 6) {
 763                 thread->debugreg6 = val;
 764                 rc = 0;
 765         } else if (n == 7) {
 766                 rc = ptrace_write_dr7(tsk, val);
 767                 if (!rc)
 768                         thread->ptrace_dr7 = val;
 769         }
 770         return rc;
 771 }
 772
 773 /*
 774  * These access the current or another (stopped) task's io permission
 775  * bitmap for debugging or core dump.
 776  */
 777 static int ioperm_active(struct task_struct *target,
 778                          const struct user_regset *regset)
 779 {
 780         return target->thread.io_bitmap_max / regset->size;
 781 }
 782
 783 static int ioperm_get(struct task_struct *target,
 784                       const struct user_regset *regset,
 785                       unsigned int pos, unsigned int count,
 786                       void *kbuf, void __user *ubuf)
 787 {
 788         if (!target->thread.io_bitmap_ptr)
 789                 return -ENXIO;
 790
 791         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 792                                    target->thread.io_bitmap_ptr,
 793                                    0, IO_BITMAP_BYTES);
 794 }
 795
 796 /*
 797  * Called by kernel/ptrace.c when detaching..
 798  *
 799  * Make sure the single step bit is not set.
 800  */
 801 void ptrace_disable(struct task_struct *child)
 802 {
 803         user_disable_single_step(child);
 804 #ifdef TIF_SYSCALL_EMU
 805         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 806 #endif
 807 }
 808
 809 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 810 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 811 #endif
 812
 813 long arch_ptrace(struct task_struct *child, long request,
 814                  unsigned long addr, unsigned long data)
 815 {
 816         int ret;
 817         unsigned long __user *datap = (unsigned long __user *)data;
 818
 819         switch (request) {
 820         /* read the word at location addr in the USER area. */
 821         case PTRACE_PEEKUSR: {
 822                 unsigned long tmp;
 823
 824                 ret = -EIO;
 825                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 826                         break;
 827
 828                 tmp = 0;  /* Default return condition */
 829                 if (addr < sizeof(struct user_regs_struct))
 830                         tmp = getreg(child, addr);
 831                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 832                          addr <= offsetof(struct user, u_debugreg[7])) {
 833                         addr -= offsetof(struct user, u_debugreg[0]);
 834                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 835                 }
 836                 ret = put_user(tmp, datap);
 837                 break;
 838         }
 839
 840         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 841                 ret = -EIO;
 842                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 843                         break;
 844
 845                 if (addr < sizeof(struct user_regs_struct))
 846                         ret = putreg(child, addr, data);
 847                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 848                          addr <= offsetof(struct user, u_debugreg[7])) {
 849                         addr -= offsetof(struct user, u_debugreg[0]);
 850                         ret = ptrace_set_debugreg(child,
 851                                                   addr / sizeof(data), data);
 852                 }
 853                 break;
 854
 855         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 856                 return copy_regset_to_user(child,
 857                                            task_user_regset_view(current),
 858                                            REGSET_GENERAL,
 859                                            0, sizeof(struct user_regs_struct),
 860                                            datap);
 861
 862         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 863                 return copy_regset_from_user(child,
 864                                              task_user_regset_view(current),
 865                                              REGSET_GENERAL,
 866                                              0, sizeof(struct user_regs_struct),
 867                                              datap);
 868
 869         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 870                 return copy_regset_to_user(child,
 871                                            task_user_regset_view(current),
 872                                            REGSET_FP,
 873                                            0, sizeof(struct user_i387_struct),
 874                                            datap);
 875
 876         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 877                 return copy_regset_from_user(child,
 878                                              task_user_regset_view(current),
 879                                              REGSET_FP,
 880                                              0, sizeof(struct user_i387_struct),
 881                                              datap);
 882
 883 #ifdef CONFIG_X86_32
 884         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
 885                 return copy_regset_to_user(child, &user_x86_32_view,
 886                                            REGSET_XFP,
 887                                            0, sizeof(struct user_fxsr_struct),
 888                                            datap) ? -EIO : 0;
 889
 890         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
 891                 return copy_regset_from_user(child, &user_x86_32_view,
 892                                              REGSET_XFP,
 893                                              0, sizeof(struct user_fxsr_struct),
 894                                              datap) ? -EIO : 0;
 895 #endif
 896
 897 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 898         case PTRACE_GET_THREAD_AREA:
 899                 if ((int) addr < 0)
 900                         return -EIO;
 901                 ret = do_get_thread_area(child, addr,
 902                                         (struct user_desc __user *)data);
 903                 break;
 904
 905         case PTRACE_SET_THREAD_AREA:
 906                 if ((int) addr < 0)
 907                         return -EIO;
 908                 ret = do_set_thread_area(child, addr,
 909                                         (struct user_desc __user *)data, 0);
 910                 break;
 911 #endif
 912
 913 #ifdef CONFIG_X86_64
 914                 /* normal 64bit interface to access TLS data.
 915                    Works just like arch_prctl, except that the arguments
 916                    are reversed. */
 917         case PTRACE_ARCH_PRCTL:
 918                 ret = do_arch_prctl(child, data, addr);
 919                 break;
 920 #endif
 921
 922         default:
 923                 ret = ptrace_request(child, request, addr, data);
 924                 break;
 925         }
 926
 927         return ret;
 928 }
 929
 930 #ifdef CONFIG_IA32_EMULATION
 931
 932 #include <linux/compat.h>
 933 #include <linux/syscalls.h>
 934 #include <asm/ia32.h>
 935 #include <asm/user32.h>
 936
 937 #define R32(l,q)                                                        \
 938         case offsetof(struct user32, regs.l):                           \
 939                 regs->q = value; break
 940
 941 #define SEG32(rs)                                                       \
 942         case offsetof(struct user32, regs.rs):                          \
 943                 return set_segment_reg(child,                           \
 944                                        offsetof(struct user_regs_struct, rs), \
 945                                        value);                          \
 946                 break
 947
 948 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 949 {
 950         struct pt_regs *regs = task_pt_regs(child);
 951
 952         switch (regno) {
 953
 954         SEG32(cs);
 955         SEG32(ds);
 956         SEG32(es);
 957         SEG32(fs);
 958         SEG32(gs);
 959         SEG32(ss);
 960
 961         R32(ebx, bx);
 962         R32(ecx, cx);
 963         R32(edx, dx);
 964         R32(edi, di);
 965         R32(esi, si);
 966         R32(ebp, bp);
 967         R32(eax, ax);
 968         R32(eip, ip);
 969         R32(esp, sp);
 970
 971         case offsetof(struct user32, regs.orig_eax):
 972                 /*
 973                  * A 32-bit debugger setting orig_eax means to restore
 974                  * the state of the task restarting a 32-bit syscall.
 975                  * Make sure we interpret the -ERESTART* codes correctly
 976                  * in case the task is not actually still sitting at the
 977                  * exit from a 32-bit syscall with TS_COMPAT still set.
 978                  */
 979                 regs->orig_ax = value;
 980                 if (syscall_get_nr(child, regs) >= 0)
 981                         task_thread_info(child)->status |= TS_COMPAT;
 982                 break;
 983
 984         case offsetof(struct user32, regs.eflags):
 985                 return set_flags(child, value);
 986
 987         case offsetof(struct user32, u_debugreg[0]) ...
 988                 offsetof(struct user32, u_debugreg[7]):
 989                 regno -= offsetof(struct user32, u_debugreg[0]);
 990                 return ptrace_set_debugreg(child, regno / 4, value);
 991
 992         default:
 993                 if (regno > sizeof(struct user32) || (regno & 3))
 994                         return -EIO;
 995
 996                 /*
 997                  * Other dummy fields in the virtual user structure
 998                  * are ignored
 999                  */
1000                 break;
1001         }
1002         return 0;
1003 }
1004
1005 #undef R32
1006 #undef SEG32
1007
1008 #define R32(l,q)                                                        \
1009         case offsetof(struct user32, regs.l):                           \
1010                 *val = regs->q; break
1011
1012 #define SEG32(rs)                                                       \
1013         case offsetof(struct user32, regs.rs):                          \
1014                 *val = get_segment_reg(child,                           \
1015                                        offsetof(struct user_regs_struct, rs)); \
1016                 break
1017
1018 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1019 {
1020         struct pt_regs *regs = task_pt_regs(child);
1021
1022         switch (regno) {
1023
1024         SEG32(ds);
1025         SEG32(es);
1026         SEG32(fs);
1027         SEG32(gs);
1028
1029         R32(cs, cs);
1030         R32(ss, ss);
1031         R32(ebx, bx);
1032         R32(ecx, cx);
1033         R32(edx, dx);
1034         R32(edi, di);
1035         R32(esi, si);
1036         R32(ebp, bp);
1037         R32(eax, ax);
1038         R32(orig_eax, orig_ax);
1039         R32(eip, ip);
1040         R32(esp, sp);
1041
1042         case offsetof(struct user32, regs.eflags):
1043                 *val = get_flags(child);
1044                 break;
1045
1046         case offsetof(struct user32, u_debugreg[0]) ...
1047                 offsetof(struct user32, u_debugreg[7]):
1048                 regno -= offsetof(struct user32, u_debugreg[0]);
1049                 *val = ptrace_get_debugreg(child, regno / 4);
1050                 break;
1051
1052         default:
1053                 if (regno > sizeof(struct user32) || (regno & 3))
1054                         return -EIO;
1055
1056                 /*
1057                  * Other dummy fields in the virtual user structure
1058                  * are ignored
1059                  */
1060                 *val = 0;
1061                 break;
1062         }
1063         return 0;
1064 }
1065
1066 #undef R32
1067 #undef SEG32
1068
1069 static int genregs32_get(struct task_struct *target,
1070                          const struct user_regset *regset,
1071                          unsigned int pos, unsigned int count,
1072                          void *kbuf, void __user *ubuf)
1073 {
1074         if (kbuf) {
1075                 compat_ulong_t *k = kbuf;
1076                 while (count >= sizeof(*k)) {
1077                         getreg32(target, pos, k++);
1078                         count -= sizeof(*k);
1079                         pos += sizeof(*k);
1080                 }
1081         } else {
1082                 compat_ulong_t __user *u = ubuf;
1083                 while (count >= sizeof(*u)) {
1084                         compat_ulong_t word;
1085                         getreg32(target, pos, &word);
1086                         if (__put_user(word, u++))
1087                                 return -EFAULT;
1088                         count -= sizeof(*u);
1089                         pos += sizeof(*u);
1090                 }
1091         }
1092
1093         return 0;
1094 }
1095
1096 static int genregs32_set(struct task_struct *target,
1097                          const struct user_regset *regset,
1098                          unsigned int pos, unsigned int count,
1099                          const void *kbuf, const void __user *ubuf)
1100 {
1101         int ret = 0;
1102         if (kbuf) {
1103                 const compat_ulong_t *k = kbuf;
1104                 while (count >= sizeof(*k) && !ret) {
1105                         ret = putreg32(target, pos, *k++);
1106                         count -= sizeof(*k);
1107                         pos += sizeof(*k);
1108                 }
1109         } else {
1110                 const compat_ulong_t __user *u = ubuf;
1111                 while (count >= sizeof(*u) && !ret) {
1112                         compat_ulong_t word;
1113                         ret = __get_user(word, u++);
1114                         if (ret)
1115                                 break;
1116                         ret = putreg32(target, pos, word);
1117                         count -= sizeof(*u);
1118                         pos += sizeof(*u);
1119                 }
1120         }
1121         return ret;
1122 }
1123
1124 static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1125                              compat_ulong_t caddr, compat_ulong_t cdata)
1126 {
1127         unsigned long addr = caddr;
1128         unsigned long data = cdata;
1129         void __user *datap = compat_ptr(data);
1130         int ret;
1131         __u32 val;
1132
1133         switch (request) {
1134         case PTRACE_PEEKUSR:
1135                 ret = getreg32(child, addr, &val);
1136                 if (ret == 0)
1137                         ret = put_user(val, (__u32 __user *)datap);
1138                 break;
1139
1140         case PTRACE_POKEUSR:
1141                 ret = putreg32(child, addr, data);
1142                 break;
1143
1144         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1145                 return copy_regset_to_user(child, &user_x86_32_view,
1146                                            REGSET_GENERAL,
1147                                            0, sizeof(struct user_regs_struct32),
1148                                            datap);
1149
1150         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1151                 return copy_regset_from_user(child, &user_x86_32_view,
1152                                              REGSET_GENERAL, 0,
1153                                              sizeof(struct user_regs_struct32),
1154                                              datap);
1155
1156         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1157                 return copy_regset_to_user(child, &user_x86_32_view,
1158                                            REGSET_FP, 0,
1159                                            sizeof(struct user_i387_ia32_struct),
1160                                            datap);
1161
1162         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1163                 return copy_regset_from_user(
1164                         child, &user_x86_32_view, REGSET_FP,
1165                         0, sizeof(struct user_i387_ia32_struct), datap);
1166
1167         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1168                 return copy_regset_to_user(child, &user_x86_32_view,
1169                                            REGSET_XFP, 0,
1170                                            sizeof(struct user32_fxsr_struct),
1171                                            datap);
1172
1173         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1174                 return copy_regset_from_user(child, &user_x86_32_view,
1175                                              REGSET_XFP, 0,
1176                                              sizeof(struct user32_fxsr_struct),
1177                                              datap);
1178
1179         case PTRACE_GET_THREAD_AREA:
1180         case PTRACE_SET_THREAD_AREA:
1181                 return arch_ptrace(child, request, addr, data);
1182
1183         default:
1184                 return compat_ptrace_request(child, request, addr, data);
1185         }
1186
1187         return ret;
1188 }
1189 #endif /* CONFIG_IA32_EMULATION */
1190
1191 #ifdef CONFIG_X86_X32_ABI
1192 static long x32_arch_ptrace(struct task_struct *child,
1193                             compat_long_t request, compat_ulong_t caddr,
1194                             compat_ulong_t cdata)
1195 {
1196         unsigned long addr = caddr;
1197         unsigned long data = cdata;
1198         void __user *datap = compat_ptr(data);
1199         int ret;
1200
1201         switch (request) {
1202         /* Read 32bits at location addr in the USER area.  Only allow
1203            to return the lower 32bits of segment and debug registers.  */
1204         case PTRACE_PEEKUSR: {
1205                 u32 tmp;
1206
1207                 ret = -EIO;
1208                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1209                     addr < offsetof(struct user_regs_struct, cs))
1210                         break;
1211
1212                 tmp = 0;  /* Default return condition */
1213                 if (addr < sizeof(struct user_regs_struct))
1214                         tmp = getreg(child, addr);
1215                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1216                          addr <= offsetof(struct user, u_debugreg[7])) {
1217                         addr -= offsetof(struct user, u_debugreg[0]);
1218                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1219                 }
1220                 ret = put_user(tmp, (__u32 __user *)datap);
1221                 break;
1222         }
1223
1224         /* Write the word at location addr in the USER area.  Only allow
1225            to update segment and debug registers with the upper 32bits
1226            zero-extended. */
1227         case PTRACE_POKEUSR:
1228                 ret = -EIO;
1229                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1230                     addr < offsetof(struct user_regs_struct, cs))
1231                         break;
1232
1233                 if (addr < sizeof(struct user_regs_struct))
1234                         ret = putreg(child, addr, data);
1235                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1236                          addr <= offsetof(struct user, u_debugreg[7])) {
1237                         addr -= offsetof(struct user, u_debugreg[0]);
1238                         ret = ptrace_set_debugreg(child,
1239                                                   addr / sizeof(data), data);
1240                 }
1241                 break;
1242
1243         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1244                 return copy_regset_to_user(child,
1245                                            task_user_regset_view(current),
1246                                            REGSET_GENERAL,
1247                                            0, sizeof(struct user_regs_struct),
1248                                            datap);
1249
1250         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1251                 return copy_regset_from_user(child,
1252                                              task_user_regset_view(current),
1253                                              REGSET_GENERAL,
1254                                              0, sizeof(struct user_regs_struct),
1255                                              datap);
1256
1257         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1258                 return copy_regset_to_user(child,
1259                                            task_user_regset_view(current),
1260                                            REGSET_FP,
1261                                            0, sizeof(struct user_i387_struct),
1262                                            datap);
1263
1264         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1265                 return copy_regset_from_user(child,
1266                                              task_user_regset_view(current),
1267                                              REGSET_FP,
1268                                              0, sizeof(struct user_i387_struct),
1269                                              datap);
1270
1271         default:
1272                 return compat_ptrace_request(child, request, addr, data);
1273         }
1274
1275         return ret;
1276 }
1277 #endif
1278
1279 #ifdef CONFIG_COMPAT
1280 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1281                         compat_ulong_t caddr, compat_ulong_t cdata)
1282 {
1283 #ifdef CONFIG_X86_X32_ABI
1284         if (!is_ia32_task())
1285                 return x32_arch_ptrace(child, request, caddr, cdata);
1286 #endif
1287 #ifdef CONFIG_IA32_EMULATION
1288         return ia32_arch_ptrace(child, request, caddr, cdata);
1289 #else
1290         return 0;
1291 #endif
1292 }
1293 #endif  /* CONFIG_COMPAT */
1294
1295 #ifdef CONFIG_X86_64
1296
1297 static struct user_regset x86_64_regsets[] __read_mostly = {
1298         [REGSET_GENERAL] = {
1299                 .core_note_type = NT_PRSTATUS,
1300                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1301                 .size = sizeof(long), .align = sizeof(long),
1302                 .get = genregs_get, .set = genregs_set
1303         },
1304         [REGSET_FP] = {
1305                 .core_note_type = NT_PRFPREG,
1306                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1307                 .size = sizeof(long), .align = sizeof(long),
1308                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1309         },
1310         [REGSET_XSTATE] = {
1311                 .core_note_type = NT_X86_XSTATE,
1312                 .size = sizeof(u64), .align = sizeof(u64),
1313                 .active = xstateregs_active, .get = xstateregs_get,
1314                 .set = xstateregs_set
1315         },
1316         [REGSET_IOPERM64] = {
1317                 .core_note_type = NT_386_IOPERM,
1318                 .n = IO_BITMAP_LONGS,
1319                 .size = sizeof(long), .align = sizeof(long),
1320                 .active = ioperm_active, .get = ioperm_get
1321         },
1322 };
1323
1324 static const struct user_regset_view user_x86_64_view = {
1325         .name = "x86_64", .e_machine = EM_X86_64,
1326         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1327 };
1328
1329 #else  /* CONFIG_X86_32 */
1330
1331 #define user_regs_struct32      user_regs_struct
1332 #define genregs32_get           genregs_get
1333 #define genregs32_set           genregs_set
1334
1335 #endif  /* CONFIG_X86_64 */
1336
1337 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1338 static struct user_regset x86_32_regsets[] __read_mostly = {
1339         [REGSET_GENERAL] = {
1340                 .core_note_type = NT_PRSTATUS,
1341                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1342                 .size = sizeof(u32), .align = sizeof(u32),
1343                 .get = genregs32_get, .set = genregs32_set
1344         },
1345         [REGSET_FP] = {
1346                 .core_note_type = NT_PRFPREG,
1347                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1348                 .size = sizeof(u32), .align = sizeof(u32),
1349                 .active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1350         },
1351         [REGSET_XFP] = {
1352                 .core_note_type = NT_PRXFPREG,
1353                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1354                 .size = sizeof(u32), .align = sizeof(u32),
1355                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1356         },
1357         [REGSET_XSTATE] = {
1358                 .core_note_type = NT_X86_XSTATE,
1359                 .size = sizeof(u64), .align = sizeof(u64),
1360                 .active = xstateregs_active, .get = xstateregs_get,
1361                 .set = xstateregs_set
1362         },
1363         [REGSET_TLS] = {
1364                 .core_note_type = NT_386_TLS,
1365                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1366                 .size = sizeof(struct user_desc),
1367                 .align = sizeof(struct user_desc),
1368                 .active = regset_tls_active,
1369                 .get = regset_tls_get, .set = regset_tls_set
1370         },
1371         [REGSET_IOPERM32] = {
1372                 .core_note_type = NT_386_IOPERM,
1373                 .n = IO_BITMAP_BYTES / sizeof(u32),
1374                 .size = sizeof(u32), .align = sizeof(u32),
1375                 .active = ioperm_active, .get = ioperm_get
1376         },
1377 };
1378
1379 static const struct user_regset_view user_x86_32_view = {
1380         .name = "i386", .e_machine = EM_386,
1381         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1382 };
1383 #endif
1384
1385 /*
1386  * This represents bytes 464..511 in the memory layout exported through
1387  * the REGSET_XSTATE interface.
1388  */
1389 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1390
1391 void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1392 {
1393 #ifdef CONFIG_X86_64
1394         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1395 #endif
1396 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1397         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1398 #endif
1399         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1400 }
1401
1402 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1403 {
1404 #ifdef CONFIG_IA32_EMULATION
1405         if (test_tsk_thread_flag(task, TIF_IA32))
1406 #endif
1407 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1408                 return &user_x86_32_view;
1409 #endif
1410 #ifdef CONFIG_X86_64
1411         return &user_x86_64_view;
1412 #endif
1413 }
1414
1415 static void fill_sigtrap_info(struct task_struct *tsk,
1416                                 struct pt_regs *regs,
1417                                 int error_code, int si_code,
1418                                 struct siginfo *info)
1419 {
1420         tsk->thread.trap_nr = X86_TRAP_DB;
1421         tsk->thread.error_code = error_code;
1422
1423         memset(info, 0, sizeof(*info));
1424         info->si_signo = SIGTRAP;
1425         info->si_code = si_code;
1426         info->si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
1427 }
1428
1429 void user_single_step_siginfo(struct task_struct *tsk,
1430                                 struct pt_regs *regs,
1431                                 struct siginfo *info)
1432 {
1433         fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1434 }
1435
1436 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1437                                          int error_code, int si_code)
1438 {
1439         struct siginfo info;
1440
1441         fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1442         /* Send us the fake SIGTRAP */
1443         force_sig_info(SIGTRAP, &info, tsk);
1444 }