arch/x86/kernel/ptrace.c

   1 /* By Ross Biro 1/23/92 */
   2 /*
   3  * Pentium III FXSR, SSE support
   4  *      Gareth Hughes <gareth@valinux.com>, May 2000
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/sched.h>
   9 #include <linux/sched/task_stack.h>
  10 #include <linux/mm.h>
  11 #include <linux/smp.h>
  12 #include <linux/errno.h>
  13 #include <linux/slab.h>
  14 #include <linux/ptrace.h>
  15 #include <linux/tracehook.h>
  16 #include <linux/user.h>
  17 #include <linux/elf.h>
  18 #include <linux/security.h>
  19 #include <linux/audit.h>
  20 #include <linux/seccomp.h>
  21 #include <linux/signal.h>
  22 #include <linux/perf_event.h>
  23 #include <linux/hw_breakpoint.h>
  24 #include <linux/rcupdate.h>
  25 #include <linux/export.h>
  26 #include <linux/context_tracking.h>
  27 #include <linux/nospec.h>
  28
  29 #include <linux/uaccess.h>
  30 #include <asm/pgtable.h>
  31 #include <asm/processor.h>
  32 #include <asm/fpu/internal.h>
  33 #include <asm/fpu/signal.h>
  34 #include <asm/fpu/regset.h>
  35 #include <asm/debugreg.h>
  36 #include <asm/ldt.h>
  37 #include <asm/desc.h>
  38 #include <asm/prctl.h>
  39 #include <asm/proto.h>
  40 #include <asm/hw_breakpoint.h>
  41 #include <asm/traps.h>
  42 #include <asm/syscall.h>
  43 #include <asm/mmu_context.h>
  44
  45 #include "tls.h"
  46
  47 enum x86_regset {
  48         REGSET_GENERAL,
  49         REGSET_FP,
  50         REGSET_XFP,
  51         REGSET_IOPERM64 = REGSET_XFP,
  52         REGSET_XSTATE,
  53         REGSET_TLS,
  54         REGSET_IOPERM32,
  55 };
  56
  57 struct pt_regs_offset {
  58         const char *name;
  59         int offset;
  60 };
  61
  62 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  63 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  64
  65 static const struct pt_regs_offset regoffset_table[] = {
  66 #ifdef CONFIG_X86_64
  67         REG_OFFSET_NAME(r15),
  68         REG_OFFSET_NAME(r14),
  69         REG_OFFSET_NAME(r13),
  70         REG_OFFSET_NAME(r12),
  71         REG_OFFSET_NAME(r11),
  72         REG_OFFSET_NAME(r10),
  73         REG_OFFSET_NAME(r9),
  74         REG_OFFSET_NAME(r8),
  75 #endif
  76         REG_OFFSET_NAME(bx),
  77         REG_OFFSET_NAME(cx),
  78         REG_OFFSET_NAME(dx),
  79         REG_OFFSET_NAME(si),
  80         REG_OFFSET_NAME(di),
  81         REG_OFFSET_NAME(bp),
  82         REG_OFFSET_NAME(ax),
  83 #ifdef CONFIG_X86_32
  84         REG_OFFSET_NAME(ds),
  85         REG_OFFSET_NAME(es),
  86         REG_OFFSET_NAME(fs),
  87         REG_OFFSET_NAME(gs),
  88 #endif
  89         REG_OFFSET_NAME(orig_ax),
  90         REG_OFFSET_NAME(ip),
  91         REG_OFFSET_NAME(cs),
  92         REG_OFFSET_NAME(flags),
  93         REG_OFFSET_NAME(sp),
  94         REG_OFFSET_NAME(ss),
  95         REG_OFFSET_END,
  96 };
  97
  98 /**
  99  * regs_query_register_offset() - query register offset from its name
 100  * @name:       the name of a register
 101  *
 102  * regs_query_register_offset() returns the offset of a register in struct
 103  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 104  */
 105 int regs_query_register_offset(const char *name)
 106 {
 107         const struct pt_regs_offset *roff;
 108         for (roff = regoffset_table; roff->name != NULL; roff++)
 109                 if (!strcmp(roff->name, name))
 110                         return roff->offset;
 111         return -EINVAL;
 112 }
 113
 114 /**
 115  * regs_query_register_name() - query register name from its offset
 116  * @offset:     the offset of a register in struct pt_regs.
 117  *
 118  * regs_query_register_name() returns the name of a register from its
 119  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 120  */
 121 const char *regs_query_register_name(unsigned int offset)
 122 {
 123         const struct pt_regs_offset *roff;
 124         for (roff = regoffset_table; roff->name != NULL; roff++)
 125                 if (roff->offset == offset)
 126                         return roff->name;
 127         return NULL;
 128 }
 129
 130 /*
 131  * does not yet catch signals sent when the child dies.
 132  * in exit.c or in signal.c.
 133  */
 134
 135 /*
 136  * Determines which flags the user has access to [1 = access, 0 = no access].
 137  */
 138 #define FLAG_MASK_32            ((unsigned long)                        \
 139                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
 140                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
 141                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
 142                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
 143                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
 144
 145 /*
 146  * Determines whether a value may be installed in a segment register.
 147  */
 148 static inline bool invalid_selector(u16 value)
 149 {
 150         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
 151 }
 152
 153 #ifdef CONFIG_X86_32
 154
 155 #define FLAG_MASK               FLAG_MASK_32
 156
 157 /*
 158  * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
 159  * when it traps.  The previous stack will be directly underneath the saved
 160  * registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
 161  *
 162  * Now, if the stack is empty, '&regs->sp' is out of range. In this
 163  * case we try to take the previous stack. To always return a non-null
 164  * stack pointer we fall back to regs as stack if no previous stack
 165  * exists.
 166  *
 167  * This is valid only for kernel mode traps.
 168  */
 169 unsigned long kernel_stack_pointer(struct pt_regs *regs)
 170 {
 171         unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
 172         unsigned long sp = (unsigned long)&regs->sp;
 173         u32 *prev_esp;
 174
 175         if (context == (sp & ~(THREAD_SIZE - 1)))
 176                 return sp;
 177
 178         prev_esp = (u32 *)(context);
 179         if (*prev_esp)
 180                 return (unsigned long)*prev_esp;
 181
 182         return (unsigned long)regs;
 183 }
 184 EXPORT_SYMBOL_GPL(kernel_stack_pointer);
 185
 186 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 187 {
 188         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 189         return &regs->bx + (regno >> 2);
 190 }
 191
 192 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 193 {
 194         /*
 195          * Returning the value truncates it to 16 bits.
 196          */
 197         unsigned int retval;
 198         if (offset != offsetof(struct user_regs_struct, gs))
 199                 retval = *pt_regs_access(task_pt_regs(task), offset);
 200         else {
 201                 if (task == current)
 202                         retval = get_user_gs(task_pt_regs(task));
 203                 else
 204                         retval = task_user_gs(task);
 205         }
 206         return retval;
 207 }
 208
 209 static int set_segment_reg(struct task_struct *task,
 210                            unsigned long offset, u16 value)
 211 {
 212         /*
 213          * The value argument was already truncated to 16 bits.
 214          */
 215         if (invalid_selector(value))
 216                 return -EIO;
 217
 218         /*
 219          * For %cs and %ss we cannot permit a null selector.
 220          * We can permit a bogus selector as long as it has USER_RPL.
 221          * Null selectors are fine for other segment registers, but
 222          * we will never get back to user mode with invalid %cs or %ss
 223          * and will take the trap in iret instead.  Much code relies
 224          * on user_mode() to distinguish a user trap frame (which can
 225          * safely use invalid selectors) from a kernel trap frame.
 226          */
 227         switch (offset) {
 228         case offsetof(struct user_regs_struct, cs):
 229         case offsetof(struct user_regs_struct, ss):
 230                 if (unlikely(value == 0))
 231                         return -EIO;
 232
 233         default:
 234                 *pt_regs_access(task_pt_regs(task), offset) = value;
 235                 break;
 236
 237         case offsetof(struct user_regs_struct, gs):
 238                 if (task == current)
 239                         set_user_gs(task_pt_regs(task), value);
 240                 else
 241                         task_user_gs(task) = value;
 242         }
 243
 244         return 0;
 245 }
 246
 247 #else  /* CONFIG_X86_64 */
 248
 249 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
 250
 251 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 252 {
 253         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 254         return &regs->r15 + (offset / sizeof(regs->r15));
 255 }
 256
 257 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 258 {
 259         /*
 260          * Returning the value truncates it to 16 bits.
 261          */
 262         unsigned int seg;
 263
 264         switch (offset) {
 265         case offsetof(struct user_regs_struct, fs):
 266                 if (task == current) {
 267                         /* Older gas can't assemble movq %?s,%r?? */
 268                         asm("movl %%fs,%0" : "=r" (seg));
 269                         return seg;
 270                 }
 271                 return task->thread.fsindex;
 272         case offsetof(struct user_regs_struct, gs):
 273                 if (task == current) {
 274                         asm("movl %%gs,%0" : "=r" (seg));
 275                         return seg;
 276                 }
 277                 return task->thread.gsindex;
 278         case offsetof(struct user_regs_struct, ds):
 279                 if (task == current) {
 280                         asm("movl %%ds,%0" : "=r" (seg));
 281                         return seg;
 282                 }
 283                 return task->thread.ds;
 284         case offsetof(struct user_regs_struct, es):
 285                 if (task == current) {
 286                         asm("movl %%es,%0" : "=r" (seg));
 287                         return seg;
 288                 }
 289                 return task->thread.es;
 290
 291         case offsetof(struct user_regs_struct, cs):
 292         case offsetof(struct user_regs_struct, ss):
 293                 break;
 294         }
 295         return *pt_regs_access(task_pt_regs(task), offset);
 296 }
 297
 298 static int set_segment_reg(struct task_struct *task,
 299                            unsigned long offset, u16 value)
 300 {
 301         /*
 302          * The value argument was already truncated to 16 bits.
 303          */
 304         if (invalid_selector(value))
 305                 return -EIO;
 306
 307         switch (offset) {
 308         case offsetof(struct user_regs_struct,fs):
 309                 task->thread.fsindex = value;
 310                 if (task == current)
 311                         loadsegment(fs, task->thread.fsindex);
 312                 break;
 313         case offsetof(struct user_regs_struct,gs):
 314                 task->thread.gsindex = value;
 315                 if (task == current)
 316                         load_gs_index(task->thread.gsindex);
 317                 break;
 318         case offsetof(struct user_regs_struct,ds):
 319                 task->thread.ds = value;
 320                 if (task == current)
 321                         loadsegment(ds, task->thread.ds);
 322                 break;
 323         case offsetof(struct user_regs_struct,es):
 324                 task->thread.es = value;
 325                 if (task == current)
 326                         loadsegment(es, task->thread.es);
 327                 break;
 328
 329                 /*
 330                  * Can't actually change these in 64-bit mode.
 331                  */
 332         case offsetof(struct user_regs_struct,cs):
 333                 if (unlikely(value == 0))
 334                         return -EIO;
 335                 task_pt_regs(task)->cs = value;
 336                 break;
 337         case offsetof(struct user_regs_struct,ss):
 338                 if (unlikely(value == 0))
 339                         return -EIO;
 340                 task_pt_regs(task)->ss = value;
 341                 break;
 342         }
 343
 344         return 0;
 345 }
 346
 347 static unsigned long task_seg_base(struct task_struct *task,
 348                                    unsigned short selector)
 349 {
 350         unsigned short idx = selector >> 3;
 351         unsigned long base;
 352
 353         if (likely((selector & SEGMENT_TI_MASK) == 0)) {
 354                 if (unlikely(idx >= GDT_ENTRIES))
 355                         return 0;
 356
 357                 /*
 358                  * There are no user segments in the GDT with nonzero bases
 359                  * other than the TLS segments.
 360                  */
 361                 if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
 362                         return 0;
 363
 364                 idx -= GDT_ENTRY_TLS_MIN;
 365                 base = get_desc_base(&task->thread.tls_array[idx]);
 366         } else {
 367 #ifdef CONFIG_MODIFY_LDT_SYSCALL
 368                 struct ldt_struct *ldt;
 369
 370                 /*
 371                  * If performance here mattered, we could protect the LDT
 372                  * with RCU.  This is a slow path, though, so we can just
 373                  * take the mutex.
 374                  */
 375                 mutex_lock(&task->mm->context.lock);
 376                 ldt = task->mm->context.ldt;
 377                 if (unlikely(!ldt || idx >= ldt->nr_entries))
 378                         base = 0;
 379                 else
 380                         base = get_desc_base(ldt->entries + idx);
 381                 mutex_unlock(&task->mm->context.lock);
 382 #else
 383                 base = 0;
 384 #endif
 385         }
 386
 387         return base;
 388 }
 389
 390 #endif  /* CONFIG_X86_32 */
 391
 392 static unsigned long get_flags(struct task_struct *task)
 393 {
 394         unsigned long retval = task_pt_regs(task)->flags;
 395
 396         /*
 397          * If the debugger set TF, hide it from the readout.
 398          */
 399         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 400                 retval &= ~X86_EFLAGS_TF;
 401
 402         return retval;
 403 }
 404
 405 static int set_flags(struct task_struct *task, unsigned long value)
 406 {
 407         struct pt_regs *regs = task_pt_regs(task);
 408
 409         /*
 410          * If the user value contains TF, mark that
 411          * it was not "us" (the debugger) that set it.
 412          * If not, make sure it stays set if we had.
 413          */
 414         if (value & X86_EFLAGS_TF)
 415                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
 416         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 417                 value |= X86_EFLAGS_TF;
 418
 419         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 420
 421         return 0;
 422 }
 423
 424 static int putreg(struct task_struct *child,
 425                   unsigned long offset, unsigned long value)
 426 {
 427         switch (offset) {
 428         case offsetof(struct user_regs_struct, cs):
 429         case offsetof(struct user_regs_struct, ds):
 430         case offsetof(struct user_regs_struct, es):
 431         case offsetof(struct user_regs_struct, fs):
 432         case offsetof(struct user_regs_struct, gs):
 433         case offsetof(struct user_regs_struct, ss):
 434                 return set_segment_reg(child, offset, value);
 435
 436         case offsetof(struct user_regs_struct, flags):
 437                 return set_flags(child, value);
 438
 439 #ifdef CONFIG_X86_64
 440         case offsetof(struct user_regs_struct,fs_base):
 441                 if (value >= TASK_SIZE_MAX)
 442                         return -EIO;
 443                 /*
 444                  * When changing the segment base, use do_arch_prctl_64
 445                  * to set either thread.fs or thread.fsindex and the
 446                  * corresponding GDT slot.
 447                  */
 448                 if (child->thread.fsbase != value)
 449                         return do_arch_prctl_64(child, ARCH_SET_FS, value);
 450                 return 0;
 451         case offsetof(struct user_regs_struct,gs_base):
 452                 /*
 453                  * Exactly the same here as the %fs handling above.
 454                  */
 455                 if (value >= TASK_SIZE_MAX)
 456                         return -EIO;
 457                 if (child->thread.gsbase != value)
 458                         return do_arch_prctl_64(child, ARCH_SET_GS, value);
 459                 return 0;
 460 #endif
 461         }
 462
 463         *pt_regs_access(task_pt_regs(child), offset) = value;
 464         return 0;
 465 }
 466
 467 static unsigned long getreg(struct task_struct *task, unsigned long offset)
 468 {
 469         switch (offset) {
 470         case offsetof(struct user_regs_struct, cs):
 471         case offsetof(struct user_regs_struct, ds):
 472         case offsetof(struct user_regs_struct, es):
 473         case offsetof(struct user_regs_struct, fs):
 474         case offsetof(struct user_regs_struct, gs):
 475         case offsetof(struct user_regs_struct, ss):
 476                 return get_segment_reg(task, offset);
 477
 478         case offsetof(struct user_regs_struct, flags):
 479                 return get_flags(task);
 480
 481 #ifdef CONFIG_X86_64
 482         case offsetof(struct user_regs_struct, fs_base): {
 483                 if (task->thread.fsindex == 0)
 484                         return task->thread.fsbase;
 485                 else
 486                         return task_seg_base(task, task->thread.fsindex);
 487         }
 488         case offsetof(struct user_regs_struct, gs_base): {
 489                 if (task->thread.gsindex == 0)
 490                         return task->thread.gsbase;
 491                 else
 492                         return task_seg_base(task, task->thread.gsindex);
 493         }
 494 #endif
 495         }
 496
 497         return *pt_regs_access(task_pt_regs(task), offset);
 498 }
 499
 500 static int genregs_get(struct task_struct *target,
 501                        const struct user_regset *regset,
 502                        unsigned int pos, unsigned int count,
 503                        void *kbuf, void __user *ubuf)
 504 {
 505         if (kbuf) {
 506                 unsigned long *k = kbuf;
 507                 while (count >= sizeof(*k)) {
 508                         *k++ = getreg(target, pos);
 509                         count -= sizeof(*k);
 510                         pos += sizeof(*k);
 511                 }
 512         } else {
 513                 unsigned long __user *u = ubuf;
 514                 while (count >= sizeof(*u)) {
 515                         if (__put_user(getreg(target, pos), u++))
 516                                 return -EFAULT;
 517                         count -= sizeof(*u);
 518                         pos += sizeof(*u);
 519                 }
 520         }
 521
 522         return 0;
 523 }
 524
 525 static int genregs_set(struct task_struct *target,
 526                        const struct user_regset *regset,
 527                        unsigned int pos, unsigned int count,
 528                        const void *kbuf, const void __user *ubuf)
 529 {
 530         int ret = 0;
 531         if (kbuf) {
 532                 const unsigned long *k = kbuf;
 533                 while (count >= sizeof(*k) && !ret) {
 534                         ret = putreg(target, pos, *k++);
 535                         count -= sizeof(*k);
 536                         pos += sizeof(*k);
 537                 }
 538         } else {
 539                 const unsigned long  __user *u = ubuf;
 540                 while (count >= sizeof(*u) && !ret) {
 541                         unsigned long word;
 542                         ret = __get_user(word, u++);
 543                         if (ret)
 544                                 break;
 545                         ret = putreg(target, pos, word);
 546                         count -= sizeof(*u);
 547                         pos += sizeof(*u);
 548                 }
 549         }
 550         return ret;
 551 }
 552
 553 static void ptrace_triggered(struct perf_event *bp,
 554                              struct perf_sample_data *data,
 555                              struct pt_regs *regs)
 556 {
 557         int i;
 558         struct thread_struct *thread = &(current->thread);
 559
 560         /*
 561          * Store in the virtual DR6 register the fact that the breakpoint
 562          * was hit so the thread's debugger will see it.
 563          */
 564         for (i = 0; i < HBP_NUM; i++) {
 565                 if (thread->ptrace_bps[i] == bp)
 566                         break;
 567         }
 568
 569         thread->debugreg6 |= (DR_TRAP0 << i);
 570 }
 571
 572 /*
 573  * Walk through every ptrace breakpoints for this thread and
 574  * build the dr7 value on top of their attributes.
 575  *
 576  */
 577 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 578 {
 579         int i;
 580         int dr7 = 0;
 581         struct arch_hw_breakpoint *info;
 582
 583         for (i = 0; i < HBP_NUM; i++) {
 584                 if (bp[i] && !bp[i]->attr.disabled) {
 585                         info = counter_arch_bp(bp[i]);
 586                         dr7 |= encode_dr7(i, info->len, info->type);
 587                 }
 588         }
 589
 590         return dr7;
 591 }
 592
 593 static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
 594                                         int len, int type, bool disabled)
 595 {
 596         int err, bp_len, bp_type;
 597
 598         err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
 599         if (!err) {
 600                 attr->bp_len = bp_len;
 601                 attr->bp_type = bp_type;
 602                 attr->disabled = disabled;
 603         }
 604
 605         return err;
 606 }
 607
 608 static struct perf_event *
 609 ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
 610                                 unsigned long addr, bool disabled)
 611 {
 612         struct perf_event_attr attr;
 613         int err;
 614
 615         ptrace_breakpoint_init(&attr);
 616         attr.bp_addr = addr;
 617
 618         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 619         if (err)
 620                 return ERR_PTR(err);
 621
 622         return register_user_hw_breakpoint(&attr, ptrace_triggered,
 623                                                  NULL, tsk);
 624 }
 625
 626 static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 627                                         int disabled)
 628 {
 629         struct perf_event_attr attr = bp->attr;
 630         int err;
 631
 632         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 633         if (err)
 634                 return err;
 635
 636         return modify_user_hw_breakpoint(bp, &attr);
 637 }
 638
 639 /*
 640  * Handle ptrace writes to debug register 7.
 641  */
 642 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 643 {
 644         struct thread_struct *thread = &tsk->thread;
 645         unsigned long old_dr7;
 646         bool second_pass = false;
 647         int i, rc, ret = 0;
 648
 649         data &= ~DR_CONTROL_RESERVED;
 650         old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 651
 652 restore:
 653         rc = 0;
 654         for (i = 0; i < HBP_NUM; i++) {
 655                 unsigned len, type;
 656                 bool disabled = !decode_dr7(data, i, &len, &type);
 657                 struct perf_event *bp = thread->ptrace_bps[i];
 658
 659                 if (!bp) {
 660                         if (disabled)
 661                                 continue;
 662
 663                         bp = ptrace_register_breakpoint(tsk,
 664                                         len, type, 0, disabled);
 665                         if (IS_ERR(bp)) {
 666                                 rc = PTR_ERR(bp);
 667                                 break;
 668                         }
 669
 670                         thread->ptrace_bps[i] = bp;
 671                         continue;
 672                 }
 673
 674                 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
 675                 if (rc)
 676                         break;
 677         }
 678
 679         /* Restore if the first pass failed, second_pass shouldn't fail. */
 680         if (rc && !WARN_ON(second_pass)) {
 681                 ret = rc;
 682                 data = old_dr7;
 683                 second_pass = true;
 684                 goto restore;
 685         }
 686
 687         return ret;
 688 }
 689
 690 /*
 691  * Handle PTRACE_PEEKUSR calls for the debug register area.
 692  */
 693 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 694 {
 695         struct thread_struct *thread = &tsk->thread;
 696         unsigned long val = 0;
 697
 698         if (n < HBP_NUM) {
 699                 int index = array_index_nospec(n, HBP_NUM);
 700                 struct perf_event *bp = thread->ptrace_bps[index];
 701
 702                 if (bp)
 703                         val = bp->hw.info.address;
 704         } else if (n == 6) {
 705                 val = thread->debugreg6;
 706         } else if (n == 7) {
 707                 val = thread->ptrace_dr7;
 708         }
 709         return val;
 710 }
 711
 712 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 713                                       unsigned long addr)
 714 {
 715         struct thread_struct *t = &tsk->thread;
 716         struct perf_event *bp = t->ptrace_bps[nr];
 717         int err = 0;
 718
 719         if (!bp) {
 720                 /*
 721                  * Put stub len and type to create an inactive but correct bp.
 722                  *
 723                  * CHECKME: the previous code returned -EIO if the addr wasn't
 724                  * a valid task virtual addr. The new one will return -EINVAL in
 725                  *  this case.
 726                  * -EINVAL may be what we want for in-kernel breakpoints users,
 727                  * but -EIO looks better for ptrace, since we refuse a register
 728                  * writing for the user. And anyway this is the previous
 729                  * behaviour.
 730                  */
 731                 bp = ptrace_register_breakpoint(tsk,
 732                                 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
 733                                 addr, true);
 734                 if (IS_ERR(bp))
 735                         err = PTR_ERR(bp);
 736                 else
 737                         t->ptrace_bps[nr] = bp;
 738         } else {
 739                 struct perf_event_attr attr = bp->attr;
 740
 741                 attr.bp_addr = addr;
 742                 err = modify_user_hw_breakpoint(bp, &attr);
 743         }
 744
 745         return err;
 746 }
 747
 748 /*
 749  * Handle PTRACE_POKEUSR calls for the debug register area.
 750  */
 751 static int ptrace_set_debugreg(struct task_struct *tsk, int n,
 752                                unsigned long val)
 753 {
 754         struct thread_struct *thread = &tsk->thread;
 755         /* There are no DR4 or DR5 registers */
 756         int rc = -EIO;
 757
 758         if (n < HBP_NUM) {
 759                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
 760         } else if (n == 6) {
 761                 thread->debugreg6 = val;
 762                 rc = 0;
 763         } else if (n == 7) {
 764                 rc = ptrace_write_dr7(tsk, val);
 765                 if (!rc)
 766                         thread->ptrace_dr7 = val;
 767         }
 768         return rc;
 769 }
 770
 771 /*
 772  * These access the current or another (stopped) task's io permission
 773  * bitmap for debugging or core dump.
 774  */
 775 static int ioperm_active(struct task_struct *target,
 776                          const struct user_regset *regset)
 777 {
 778         return target->thread.io_bitmap_max / regset->size;
 779 }
 780
 781 static int ioperm_get(struct task_struct *target,
 782                       const struct user_regset *regset,
 783                       unsigned int pos, unsigned int count,
 784                       void *kbuf, void __user *ubuf)
 785 {
 786         if (!target->thread.io_bitmap_ptr)
 787                 return -ENXIO;
 788
 789         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 790                                    target->thread.io_bitmap_ptr,
 791                                    0, IO_BITMAP_BYTES);
 792 }
 793
 794 /*
 795  * Called by kernel/ptrace.c when detaching..
 796  *
 797  * Make sure the single step bit is not set.
 798  */
 799 void ptrace_disable(struct task_struct *child)
 800 {
 801         user_disable_single_step(child);
 802 #ifdef TIF_SYSCALL_EMU
 803         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 804 #endif
 805 }
 806
 807 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 808 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 809 #endif
 810
 811 long arch_ptrace(struct task_struct *child, long request,
 812                  unsigned long addr, unsigned long data)
 813 {
 814         int ret;
 815         unsigned long __user *datap = (unsigned long __user *)data;
 816
 817         switch (request) {
 818         /* read the word at location addr in the USER area. */
 819         case PTRACE_PEEKUSR: {
 820                 unsigned long tmp;
 821
 822                 ret = -EIO;
 823                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 824                         break;
 825
 826                 tmp = 0;  /* Default return condition */
 827                 if (addr < sizeof(struct user_regs_struct))
 828                         tmp = getreg(child, addr);
 829                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 830                          addr <= offsetof(struct user, u_debugreg[7])) {
 831                         addr -= offsetof(struct user, u_debugreg[0]);
 832                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 833                 }
 834                 ret = put_user(tmp, datap);
 835                 break;
 836         }
 837
 838         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 839                 ret = -EIO;
 840                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 841                         break;
 842
 843                 if (addr < sizeof(struct user_regs_struct))
 844                         ret = putreg(child, addr, data);
 845                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 846                          addr <= offsetof(struct user, u_debugreg[7])) {
 847                         addr -= offsetof(struct user, u_debugreg[0]);
 848                         ret = ptrace_set_debugreg(child,
 849                                                   addr / sizeof(data), data);
 850                 }
 851                 break;
 852
 853         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 854                 return copy_regset_to_user(child,
 855                                            task_user_regset_view(current),
 856                                            REGSET_GENERAL,
 857                                            0, sizeof(struct user_regs_struct),
 858                                            datap);
 859
 860         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 861                 return copy_regset_from_user(child,
 862                                              task_user_regset_view(current),
 863                                              REGSET_GENERAL,
 864                                              0, sizeof(struct user_regs_struct),
 865                                              datap);
 866
 867         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 868                 return copy_regset_to_user(child,
 869                                            task_user_regset_view(current),
 870                                            REGSET_FP,
 871                                            0, sizeof(struct user_i387_struct),
 872                                            datap);
 873
 874         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 875                 return copy_regset_from_user(child,
 876                                              task_user_regset_view(current),
 877                                              REGSET_FP,
 878                                              0, sizeof(struct user_i387_struct),
 879                                              datap);
 880
 881 #ifdef CONFIG_X86_32
 882         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
 883                 return copy_regset_to_user(child, &user_x86_32_view,
 884                                            REGSET_XFP,
 885                                            0, sizeof(struct user_fxsr_struct),
 886                                            datap) ? -EIO : 0;
 887
 888         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
 889                 return copy_regset_from_user(child, &user_x86_32_view,
 890                                              REGSET_XFP,
 891                                              0, sizeof(struct user_fxsr_struct),
 892                                              datap) ? -EIO : 0;
 893 #endif
 894
 895 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 896         case PTRACE_GET_THREAD_AREA:
 897                 if ((int) addr < 0)
 898                         return -EIO;
 899                 ret = do_get_thread_area(child, addr,
 900                                         (struct user_desc __user *)data);
 901                 break;
 902
 903         case PTRACE_SET_THREAD_AREA:
 904                 if ((int) addr < 0)
 905                         return -EIO;
 906                 ret = do_set_thread_area(child, addr,
 907                                         (struct user_desc __user *)data, 0);
 908                 break;
 909 #endif
 910
 911 #ifdef CONFIG_X86_64
 912                 /* normal 64bit interface to access TLS data.
 913                    Works just like arch_prctl, except that the arguments
 914                    are reversed. */
 915         case PTRACE_ARCH_PRCTL:
 916                 ret = do_arch_prctl_64(child, data, addr);
 917                 break;
 918 #endif
 919
 920         default:
 921                 ret = ptrace_request(child, request, addr, data);
 922                 break;
 923         }
 924
 925         return ret;
 926 }
 927
 928 #ifdef CONFIG_IA32_EMULATION
 929
 930 #include <linux/compat.h>
 931 #include <linux/syscalls.h>
 932 #include <asm/ia32.h>
 933 #include <asm/user32.h>
 934
 935 #define R32(l,q)                                                        \
 936         case offsetof(struct user32, regs.l):                           \
 937                 regs->q = value; break
 938
 939 #define SEG32(rs)                                                       \
 940         case offsetof(struct user32, regs.rs):                          \
 941                 return set_segment_reg(child,                           \
 942                                        offsetof(struct user_regs_struct, rs), \
 943                                        value);                          \
 944                 break
 945
 946 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 947 {
 948         struct pt_regs *regs = task_pt_regs(child);
 949
 950         switch (regno) {
 951
 952         SEG32(cs);
 953         SEG32(ds);
 954         SEG32(es);
 955         SEG32(fs);
 956         SEG32(gs);
 957         SEG32(ss);
 958
 959         R32(ebx, bx);
 960         R32(ecx, cx);
 961         R32(edx, dx);
 962         R32(edi, di);
 963         R32(esi, si);
 964         R32(ebp, bp);
 965         R32(eax, ax);
 966         R32(eip, ip);
 967         R32(esp, sp);
 968
 969         case offsetof(struct user32, regs.orig_eax):
 970                 /*
 971                  * Warning: bizarre corner case fixup here.  A 32-bit
 972                  * debugger setting orig_eax to -1 wants to disable
 973                  * syscall restart.  Make sure that the syscall
 974                  * restart code sign-extends orig_ax.  Also make sure
 975                  * we interpret the -ERESTART* codes correctly if
 976                  * loaded into regs->ax in case the task is not
 977                  * actually still sitting at the exit from a 32-bit
 978                  * syscall with TS_COMPAT still set.
 979                  */
 980                 regs->orig_ax = value;
 981                 if (syscall_get_nr(child, regs) >= 0)
 982                         child->thread_info.status |= TS_I386_REGS_POKED;
 983                 break;
 984
 985         case offsetof(struct user32, regs.eflags):
 986                 return set_flags(child, value);
 987
 988         case offsetof(struct user32, u_debugreg[0]) ...
 989                 offsetof(struct user32, u_debugreg[7]):
 990                 regno -= offsetof(struct user32, u_debugreg[0]);
 991                 return ptrace_set_debugreg(child, regno / 4, value);
 992
 993         default:
 994                 if (regno > sizeof(struct user32) || (regno & 3))
 995                         return -EIO;
 996
 997                 /*
 998                  * Other dummy fields in the virtual user structure
 999                  * are ignored
1000                  */
1001                 break;
1002         }
1003         return 0;
1004 }
1005
1006 #undef R32
1007 #undef SEG32
1008
1009 #define R32(l,q)                                                        \
1010         case offsetof(struct user32, regs.l):                           \
1011                 *val = regs->q; break
1012
1013 #define SEG32(rs)                                                       \
1014         case offsetof(struct user32, regs.rs):                          \
1015                 *val = get_segment_reg(child,                           \
1016                                        offsetof(struct user_regs_struct, rs)); \
1017                 break
1018
1019 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1020 {
1021         struct pt_regs *regs = task_pt_regs(child);
1022
1023         switch (regno) {
1024
1025         SEG32(ds);
1026         SEG32(es);
1027         SEG32(fs);
1028         SEG32(gs);
1029
1030         R32(cs, cs);
1031         R32(ss, ss);
1032         R32(ebx, bx);
1033         R32(ecx, cx);
1034         R32(edx, dx);
1035         R32(edi, di);
1036         R32(esi, si);
1037         R32(ebp, bp);
1038         R32(eax, ax);
1039         R32(orig_eax, orig_ax);
1040         R32(eip, ip);
1041         R32(esp, sp);
1042
1043         case offsetof(struct user32, regs.eflags):
1044                 *val = get_flags(child);
1045                 break;
1046
1047         case offsetof(struct user32, u_debugreg[0]) ...
1048                 offsetof(struct user32, u_debugreg[7]):
1049                 regno -= offsetof(struct user32, u_debugreg[0]);
1050                 *val = ptrace_get_debugreg(child, regno / 4);
1051                 break;
1052
1053         default:
1054                 if (regno > sizeof(struct user32) || (regno & 3))
1055                         return -EIO;
1056
1057                 /*
1058                  * Other dummy fields in the virtual user structure
1059                  * are ignored
1060                  */
1061                 *val = 0;
1062                 break;
1063         }
1064         return 0;
1065 }
1066
1067 #undef R32
1068 #undef SEG32
1069
1070 static int genregs32_get(struct task_struct *target,
1071                          const struct user_regset *regset,
1072                          unsigned int pos, unsigned int count,
1073                          void *kbuf, void __user *ubuf)
1074 {
1075         if (kbuf) {
1076                 compat_ulong_t *k = kbuf;
1077                 while (count >= sizeof(*k)) {
1078                         getreg32(target, pos, k++);
1079                         count -= sizeof(*k);
1080                         pos += sizeof(*k);
1081                 }
1082         } else {
1083                 compat_ulong_t __user *u = ubuf;
1084                 while (count >= sizeof(*u)) {
1085                         compat_ulong_t word;
1086                         getreg32(target, pos, &word);
1087                         if (__put_user(word, u++))
1088                                 return -EFAULT;
1089                         count -= sizeof(*u);
1090                         pos += sizeof(*u);
1091                 }
1092         }
1093
1094         return 0;
1095 }
1096
1097 static int genregs32_set(struct task_struct *target,
1098                          const struct user_regset *regset,
1099                          unsigned int pos, unsigned int count,
1100                          const void *kbuf, const void __user *ubuf)
1101 {
1102         int ret = 0;
1103         if (kbuf) {
1104                 const compat_ulong_t *k = kbuf;
1105                 while (count >= sizeof(*k) && !ret) {
1106                         ret = putreg32(target, pos, *k++);
1107                         count -= sizeof(*k);
1108                         pos += sizeof(*k);
1109                 }
1110         } else {
1111                 const compat_ulong_t __user *u = ubuf;
1112                 while (count >= sizeof(*u) && !ret) {
1113                         compat_ulong_t word;
1114                         ret = __get_user(word, u++);
1115                         if (ret)
1116                                 break;
1117                         ret = putreg32(target, pos, word);
1118                         count -= sizeof(*u);
1119                         pos += sizeof(*u);
1120                 }
1121         }
1122         return ret;
1123 }
1124
1125 static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1126                              compat_ulong_t caddr, compat_ulong_t cdata)
1127 {
1128         unsigned long addr = caddr;
1129         unsigned long data = cdata;
1130         void __user *datap = compat_ptr(data);
1131         int ret;
1132         __u32 val;
1133
1134         switch (request) {
1135         case PTRACE_PEEKUSR:
1136                 ret = getreg32(child, addr, &val);
1137                 if (ret == 0)
1138                         ret = put_user(val, (__u32 __user *)datap);
1139                 break;
1140
1141         case PTRACE_POKEUSR:
1142                 ret = putreg32(child, addr, data);
1143                 break;
1144
1145         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1146                 return copy_regset_to_user(child, &user_x86_32_view,
1147                                            REGSET_GENERAL,
1148                                            0, sizeof(struct user_regs_struct32),
1149                                            datap);
1150
1151         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1152                 return copy_regset_from_user(child, &user_x86_32_view,
1153                                              REGSET_GENERAL, 0,
1154                                              sizeof(struct user_regs_struct32),
1155                                              datap);
1156
1157         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1158                 return copy_regset_to_user(child, &user_x86_32_view,
1159                                            REGSET_FP, 0,
1160                                            sizeof(struct user_i387_ia32_struct),
1161                                            datap);
1162
1163         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1164                 return copy_regset_from_user(
1165                         child, &user_x86_32_view, REGSET_FP,
1166                         0, sizeof(struct user_i387_ia32_struct), datap);
1167
1168         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1169                 return copy_regset_to_user(child, &user_x86_32_view,
1170                                            REGSET_XFP, 0,
1171                                            sizeof(struct user32_fxsr_struct),
1172                                            datap);
1173
1174         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1175                 return copy_regset_from_user(child, &user_x86_32_view,
1176                                              REGSET_XFP, 0,
1177                                              sizeof(struct user32_fxsr_struct),
1178                                              datap);
1179
1180         case PTRACE_GET_THREAD_AREA:
1181         case PTRACE_SET_THREAD_AREA:
1182                 return arch_ptrace(child, request, addr, data);
1183
1184         default:
1185                 return compat_ptrace_request(child, request, addr, data);
1186         }
1187
1188         return ret;
1189 }
1190 #endif /* CONFIG_IA32_EMULATION */
1191
1192 #ifdef CONFIG_X86_X32_ABI
1193 static long x32_arch_ptrace(struct task_struct *child,
1194                             compat_long_t request, compat_ulong_t caddr,
1195                             compat_ulong_t cdata)
1196 {
1197         unsigned long addr = caddr;
1198         unsigned long data = cdata;
1199         void __user *datap = compat_ptr(data);
1200         int ret;
1201
1202         switch (request) {
1203         /* Read 32bits at location addr in the USER area.  Only allow
1204            to return the lower 32bits of segment and debug registers.  */
1205         case PTRACE_PEEKUSR: {
1206                 u32 tmp;
1207
1208                 ret = -EIO;
1209                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1210                     addr < offsetof(struct user_regs_struct, cs))
1211                         break;
1212
1213                 tmp = 0;  /* Default return condition */
1214                 if (addr < sizeof(struct user_regs_struct))
1215                         tmp = getreg(child, addr);
1216                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1217                          addr <= offsetof(struct user, u_debugreg[7])) {
1218                         addr -= offsetof(struct user, u_debugreg[0]);
1219                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1220                 }
1221                 ret = put_user(tmp, (__u32 __user *)datap);
1222                 break;
1223         }
1224
1225         /* Write the word at location addr in the USER area.  Only allow
1226            to update segment and debug registers with the upper 32bits
1227            zero-extended. */
1228         case PTRACE_POKEUSR:
1229                 ret = -EIO;
1230                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1231                     addr < offsetof(struct user_regs_struct, cs))
1232                         break;
1233
1234                 if (addr < sizeof(struct user_regs_struct))
1235                         ret = putreg(child, addr, data);
1236                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1237                          addr <= offsetof(struct user, u_debugreg[7])) {
1238                         addr -= offsetof(struct user, u_debugreg[0]);
1239                         ret = ptrace_set_debugreg(child,
1240                                                   addr / sizeof(data), data);
1241                 }
1242                 break;
1243
1244         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1245                 return copy_regset_to_user(child,
1246                                            task_user_regset_view(current),
1247                                            REGSET_GENERAL,
1248                                            0, sizeof(struct user_regs_struct),
1249                                            datap);
1250
1251         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1252                 return copy_regset_from_user(child,
1253                                              task_user_regset_view(current),
1254                                              REGSET_GENERAL,
1255                                              0, sizeof(struct user_regs_struct),
1256                                              datap);
1257
1258         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1259                 return copy_regset_to_user(child,
1260                                            task_user_regset_view(current),
1261                                            REGSET_FP,
1262                                            0, sizeof(struct user_i387_struct),
1263                                            datap);
1264
1265         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1266                 return copy_regset_from_user(child,
1267                                              task_user_regset_view(current),
1268                                              REGSET_FP,
1269                                              0, sizeof(struct user_i387_struct),
1270                                              datap);
1271
1272         default:
1273                 return compat_ptrace_request(child, request, addr, data);
1274         }
1275
1276         return ret;
1277 }
1278 #endif
1279
1280 #ifdef CONFIG_COMPAT
1281 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1282                         compat_ulong_t caddr, compat_ulong_t cdata)
1283 {
1284 #ifdef CONFIG_X86_X32_ABI
1285         if (!in_ia32_syscall())
1286                 return x32_arch_ptrace(child, request, caddr, cdata);
1287 #endif
1288 #ifdef CONFIG_IA32_EMULATION
1289         return ia32_arch_ptrace(child, request, caddr, cdata);
1290 #else
1291         return 0;
1292 #endif
1293 }
1294 #endif  /* CONFIG_COMPAT */
1295
1296 #ifdef CONFIG_X86_64
1297
1298 static struct user_regset x86_64_regsets[] __ro_after_init = {
1299         [REGSET_GENERAL] = {
1300                 .core_note_type = NT_PRSTATUS,
1301                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1302                 .size = sizeof(long), .align = sizeof(long),
1303                 .get = genregs_get, .set = genregs_set
1304         },
1305         [REGSET_FP] = {
1306                 .core_note_type = NT_PRFPREG,
1307                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1308                 .size = sizeof(long), .align = sizeof(long),
1309                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1310         },
1311         [REGSET_XSTATE] = {
1312                 .core_note_type = NT_X86_XSTATE,
1313                 .size = sizeof(u64), .align = sizeof(u64),
1314                 .active = xstateregs_active, .get = xstateregs_get,
1315                 .set = xstateregs_set
1316         },
1317         [REGSET_IOPERM64] = {
1318                 .core_note_type = NT_386_IOPERM,
1319                 .n = IO_BITMAP_LONGS,
1320                 .size = sizeof(long), .align = sizeof(long),
1321                 .active = ioperm_active, .get = ioperm_get
1322         },
1323 };
1324
1325 static const struct user_regset_view user_x86_64_view = {
1326         .name = "x86_64", .e_machine = EM_X86_64,
1327         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1328 };
1329
1330 #else  /* CONFIG_X86_32 */
1331
1332 #define user_regs_struct32      user_regs_struct
1333 #define genregs32_get           genregs_get
1334 #define genregs32_set           genregs_set
1335
1336 #endif  /* CONFIG_X86_64 */
1337
1338 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1339 static struct user_regset x86_32_regsets[] __ro_after_init = {
1340         [REGSET_GENERAL] = {
1341                 .core_note_type = NT_PRSTATUS,
1342                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1343                 .size = sizeof(u32), .align = sizeof(u32),
1344                 .get = genregs32_get, .set = genregs32_set
1345         },
1346         [REGSET_FP] = {
1347                 .core_note_type = NT_PRFPREG,
1348                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1349                 .size = sizeof(u32), .align = sizeof(u32),
1350                 .active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1351         },
1352         [REGSET_XFP] = {
1353                 .core_note_type = NT_PRXFPREG,
1354                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1355                 .size = sizeof(u32), .align = sizeof(u32),
1356                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1357         },
1358         [REGSET_XSTATE] = {
1359                 .core_note_type = NT_X86_XSTATE,
1360                 .size = sizeof(u64), .align = sizeof(u64),
1361                 .active = xstateregs_active, .get = xstateregs_get,
1362                 .set = xstateregs_set
1363         },
1364         [REGSET_TLS] = {
1365                 .core_note_type = NT_386_TLS,
1366                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1367                 .size = sizeof(struct user_desc),
1368                 .align = sizeof(struct user_desc),
1369                 .active = regset_tls_active,
1370                 .get = regset_tls_get, .set = regset_tls_set
1371         },
1372         [REGSET_IOPERM32] = {
1373                 .core_note_type = NT_386_IOPERM,
1374                 .n = IO_BITMAP_BYTES / sizeof(u32),
1375                 .size = sizeof(u32), .align = sizeof(u32),
1376                 .active = ioperm_active, .get = ioperm_get
1377         },
1378 };
1379
1380 static const struct user_regset_view user_x86_32_view = {
1381         .name = "i386", .e_machine = EM_386,
1382         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1383 };
1384 #endif
1385
1386 /*
1387  * This represents bytes 464..511 in the memory layout exported through
1388  * the REGSET_XSTATE interface.
1389  */
1390 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1391
1392 void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1393 {
1394 #ifdef CONFIG_X86_64
1395         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1396 #endif
1397 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1398         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1399 #endif
1400         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1401 }
1402
1403 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1404 {
1405 #ifdef CONFIG_IA32_EMULATION
1406         if (!user_64bit_mode(task_pt_regs(task)))
1407 #endif
1408 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1409                 return &user_x86_32_view;
1410 #endif
1411 #ifdef CONFIG_X86_64
1412         return &user_x86_64_view;
1413 #endif
1414 }
1415
1416 static void fill_sigtrap_info(struct task_struct *tsk,
1417                                 struct pt_regs *regs,
1418                                 int error_code, int si_code,
1419                                 struct siginfo *info)
1420 {
1421         tsk->thread.trap_nr = X86_TRAP_DB;
1422         tsk->thread.error_code = error_code;
1423
1424         memset(info, 0, sizeof(*info));
1425         info->si_signo = SIGTRAP;
1426         info->si_code = si_code;
1427         info->si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
1428 }
1429
1430 void user_single_step_siginfo(struct task_struct *tsk,
1431                                 struct pt_regs *regs,
1432                                 struct siginfo *info)
1433 {
1434         fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1435 }
1436
1437 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1438                                          int error_code, int si_code)
1439 {
1440         struct siginfo info;
1441
1442         fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1443         /* Send us the fake SIGTRAP */
1444         force_sig_info(SIGTRAP, &info, tsk);
1445 }