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/regset.h>
  15 #include <linux/tracehook.h>
  16 #include <linux/user.h>
  17 #include <linux/elf.h>
  18 #include <linux/security.h>
  19 #include <linux/audit.h>
  20 #include <linux/seccomp.h>
  21 #include <linux/signal.h>
  22 #include <linux/perf_event.h>
  23 #include <linux/hw_breakpoint.h>
  24 #include <linux/rcupdate.h>
  25 #include <linux/export.h>
  26 #include <linux/context_tracking.h>
  27
  28 #include <asm/uaccess.h>
  29 #include <asm/pgtable.h>
  30 #include <asm/processor.h>
  31 #include <asm/i387.h>
  32 #include <asm/fpu-internal.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
  41 #include "tls.h"
  42
  43 #define CREATE_TRACE_POINTS
  44 #include <trace/events/syscalls.h>
  45
  46 enum x86_regset {
  47         REGSET_GENERAL,
  48         REGSET_FP,
  49         REGSET_XFP,
  50         REGSET_IOPERM64 = REGSET_XFP,
  51         REGSET_XSTATE,
  52         REGSET_TLS,
  53         REGSET_IOPERM32,
  54 };
  55
  56 struct pt_regs_offset {
  57         const char *name;
  58         int offset;
  59 };
  60
  61 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
  62 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  63
  64 static const struct pt_regs_offset regoffset_table[] = {
  65 #ifdef CONFIG_X86_64
  66         REG_OFFSET_NAME(r15),
  67         REG_OFFSET_NAME(r14),
  68         REG_OFFSET_NAME(r13),
  69         REG_OFFSET_NAME(r12),
  70         REG_OFFSET_NAME(r11),
  71         REG_OFFSET_NAME(r10),
  72         REG_OFFSET_NAME(r9),
  73         REG_OFFSET_NAME(r8),
  74 #endif
  75         REG_OFFSET_NAME(bx),
  76         REG_OFFSET_NAME(cx),
  77         REG_OFFSET_NAME(dx),
  78         REG_OFFSET_NAME(si),
  79         REG_OFFSET_NAME(di),
  80         REG_OFFSET_NAME(bp),
  81         REG_OFFSET_NAME(ax),
  82 #ifdef CONFIG_X86_32
  83         REG_OFFSET_NAME(ds),
  84         REG_OFFSET_NAME(es),
  85         REG_OFFSET_NAME(fs),
  86         REG_OFFSET_NAME(gs),
  87 #endif
  88         REG_OFFSET_NAME(orig_ax),
  89         REG_OFFSET_NAME(ip),
  90         REG_OFFSET_NAME(cs),
  91         REG_OFFSET_NAME(flags),
  92         REG_OFFSET_NAME(sp),
  93         REG_OFFSET_NAME(ss),
  94         REG_OFFSET_END,
  95 };
  96
  97 /**
  98  * regs_query_register_offset() - query register offset from its name
  99  * @name:       the name of a register
 100  *
 101  * regs_query_register_offset() returns the offset of a register in struct
 102  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 103  */
 104 int regs_query_register_offset(const char *name)
 105 {
 106         const struct pt_regs_offset *roff;
 107         for (roff = regoffset_table; roff->name != NULL; roff++)
 108                 if (!strcmp(roff->name, name))
 109                         return roff->offset;
 110         return -EINVAL;
 111 }
 112
 113 /**
 114  * regs_query_register_name() - query register name from its offset
 115  * @offset:     the offset of a register in struct pt_regs.
 116  *
 117  * regs_query_register_name() returns the name of a register from its
 118  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 119  */
 120 const char *regs_query_register_name(unsigned int offset)
 121 {
 122         const struct pt_regs_offset *roff;
 123         for (roff = regoffset_table; roff->name != NULL; roff++)
 124                 if (roff->offset == offset)
 125                         return roff->name;
 126         return NULL;
 127 }
 128
 129 static const int arg_offs_table[] = {
 130 #ifdef CONFIG_X86_32
 131         [0] = offsetof(struct pt_regs, ax),
 132         [1] = offsetof(struct pt_regs, dx),
 133         [2] = offsetof(struct pt_regs, cx)
 134 #else /* CONFIG_X86_64 */
 135         [0] = offsetof(struct pt_regs, di),
 136         [1] = offsetof(struct pt_regs, si),
 137         [2] = offsetof(struct pt_regs, dx),
 138         [3] = offsetof(struct pt_regs, cx),
 139         [4] = offsetof(struct pt_regs, r8),
 140         [5] = offsetof(struct pt_regs, r9)
 141 #endif
 142 };
 143
 144 /*
 145  * does not yet catch signals sent when the child dies.
 146  * in exit.c or in signal.c.
 147  */
 148
 149 /*
 150  * Determines which flags the user has access to [1 = access, 0 = no access].
 151  */
 152 #define FLAG_MASK_32            ((unsigned long)                        \
 153                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
 154                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
 155                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
 156                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
 157                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
 158
 159 /*
 160  * Determines whether a value may be installed in a segment register.
 161  */
 162 static inline bool invalid_selector(u16 value)
 163 {
 164         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
 165 }
 166
 167 #ifdef CONFIG_X86_32
 168
 169 #define FLAG_MASK               FLAG_MASK_32
 170
 171 /*
 172  * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
 173  * when it traps.  The previous stack will be directly underneath the saved
 174  * registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
 175  *
 176  * Now, if the stack is empty, '&regs->sp' is out of range. In this
 177  * case we try to take the previous stack. To always return a non-null
 178  * stack pointer we fall back to regs as stack if no previous stack
 179  * exists.
 180  *
 181  * This is valid only for kernel mode traps.
 182  */
 183 unsigned long kernel_stack_pointer(struct pt_regs *regs)
 184 {
 185         unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
 186         unsigned long sp = (unsigned long)&regs->sp;
 187         struct thread_info *tinfo;
 188
 189         if (context == (sp & ~(THREAD_SIZE - 1)))
 190                 return sp;
 191
 192         tinfo = (struct thread_info *)context;
 193         if (tinfo->previous_esp)
 194                 return tinfo->previous_esp;
 195
 196         return (unsigned long)regs;
 197 }
 198 EXPORT_SYMBOL_GPL(kernel_stack_pointer);
 199
 200 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 201 {
 202         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 203         return &regs->bx + (regno >> 2);
 204 }
 205
 206 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 207 {
 208         /*
 209          * Returning the value truncates it to 16 bits.
 210          */
 211         unsigned int retval;
 212         if (offset != offsetof(struct user_regs_struct, gs))
 213                 retval = *pt_regs_access(task_pt_regs(task), offset);
 214         else {
 215                 if (task == current)
 216                         retval = get_user_gs(task_pt_regs(task));
 217                 else
 218                         retval = task_user_gs(task);
 219         }
 220         return retval;
 221 }
 222
 223 static int set_segment_reg(struct task_struct *task,
 224                            unsigned long offset, u16 value)
 225 {
 226         /*
 227          * The value argument was already truncated to 16 bits.
 228          */
 229         if (invalid_selector(value))
 230                 return -EIO;
 231
 232         /*
 233          * For %cs and %ss we cannot permit a null selector.
 234          * We can permit a bogus selector as long as it has USER_RPL.
 235          * Null selectors are fine for other segment registers, but
 236          * we will never get back to user mode with invalid %cs or %ss
 237          * and will take the trap in iret instead.  Much code relies
 238          * on user_mode() to distinguish a user trap frame (which can
 239          * safely use invalid selectors) from a kernel trap frame.
 240          */
 241         switch (offset) {
 242         case offsetof(struct user_regs_struct, cs):
 243         case offsetof(struct user_regs_struct, ss):
 244                 if (unlikely(value == 0))
 245                         return -EIO;
 246
 247         default:
 248                 *pt_regs_access(task_pt_regs(task), offset) = value;
 249                 break;
 250
 251         case offsetof(struct user_regs_struct, gs):
 252                 if (task == current)
 253                         set_user_gs(task_pt_regs(task), value);
 254                 else
 255                         task_user_gs(task) = value;
 256         }
 257
 258         return 0;
 259 }
 260
 261 #else  /* CONFIG_X86_64 */
 262
 263 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
 264
 265 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 266 {
 267         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 268         return &regs->r15 + (offset / sizeof(regs->r15));
 269 }
 270
 271 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 272 {
 273         /*
 274          * Returning the value truncates it to 16 bits.
 275          */
 276         unsigned int seg;
 277
 278         switch (offset) {
 279         case offsetof(struct user_regs_struct, fs):
 280                 if (task == current) {
 281                         /* Older gas can't assemble movq %?s,%r?? */
 282                         asm("movl %%fs,%0" : "=r" (seg));
 283                         return seg;
 284                 }
 285                 return task->thread.fsindex;
 286         case offsetof(struct user_regs_struct, gs):
 287                 if (task == current) {
 288                         asm("movl %%gs,%0" : "=r" (seg));
 289                         return seg;
 290                 }
 291                 return task->thread.gsindex;
 292         case offsetof(struct user_regs_struct, ds):
 293                 if (task == current) {
 294                         asm("movl %%ds,%0" : "=r" (seg));
 295                         return seg;
 296                 }
 297                 return task->thread.ds;
 298         case offsetof(struct user_regs_struct, es):
 299                 if (task == current) {
 300                         asm("movl %%es,%0" : "=r" (seg));
 301                         return seg;
 302                 }
 303                 return task->thread.es;
 304
 305         case offsetof(struct user_regs_struct, cs):
 306         case offsetof(struct user_regs_struct, ss):
 307                 break;
 308         }
 309         return *pt_regs_access(task_pt_regs(task), offset);
 310 }
 311
 312 static int set_segment_reg(struct task_struct *task,
 313                            unsigned long offset, u16 value)
 314 {
 315         /*
 316          * The value argument was already truncated to 16 bits.
 317          */
 318         if (invalid_selector(value))
 319                 return -EIO;
 320
 321         switch (offset) {
 322         case offsetof(struct user_regs_struct,fs):
 323                 /*
 324                  * If this is setting fs as for normal 64-bit use but
 325                  * setting fs_base has implicitly changed it, leave it.
 326                  */
 327                 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
 328                      task->thread.fs != 0) ||
 329                     (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
 330                      task->thread.fs == 0))
 331                         break;
 332                 task->thread.fsindex = value;
 333                 if (task == current)
 334                         loadsegment(fs, task->thread.fsindex);
 335                 break;
 336         case offsetof(struct user_regs_struct,gs):
 337                 /*
 338                  * If this is setting gs as for normal 64-bit use but
 339                  * setting gs_base has implicitly changed it, leave it.
 340                  */
 341                 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
 342                      task->thread.gs != 0) ||
 343                     (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
 344                      task->thread.gs == 0))
 345                         break;
 346                 task->thread.gsindex = value;
 347                 if (task == current)
 348                         load_gs_index(task->thread.gsindex);
 349                 break;
 350         case offsetof(struct user_regs_struct,ds):
 351                 task->thread.ds = value;
 352                 if (task == current)
 353                         loadsegment(ds, task->thread.ds);
 354                 break;
 355         case offsetof(struct user_regs_struct,es):
 356                 task->thread.es = value;
 357                 if (task == current)
 358                         loadsegment(es, task->thread.es);
 359                 break;
 360
 361                 /*
 362                  * Can't actually change these in 64-bit mode.
 363                  */
 364         case offsetof(struct user_regs_struct,cs):
 365                 if (unlikely(value == 0))
 366                         return -EIO;
 367 #ifdef CONFIG_IA32_EMULATION
 368                 if (test_tsk_thread_flag(task, TIF_IA32))
 369                         task_pt_regs(task)->cs = value;
 370 #endif
 371                 break;
 372         case offsetof(struct user_regs_struct,ss):
 373                 if (unlikely(value == 0))
 374                         return -EIO;
 375 #ifdef CONFIG_IA32_EMULATION
 376                 if (test_tsk_thread_flag(task, TIF_IA32))
 377                         task_pt_regs(task)->ss = value;
 378 #endif
 379                 break;
 380         }
 381
 382         return 0;
 383 }
 384
 385 #endif  /* CONFIG_X86_32 */
 386
 387 static unsigned long get_flags(struct task_struct *task)
 388 {
 389         unsigned long retval = task_pt_regs(task)->flags;
 390
 391         /*
 392          * If the debugger set TF, hide it from the readout.
 393          */
 394         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 395                 retval &= ~X86_EFLAGS_TF;
 396
 397         return retval;
 398 }
 399
 400 static int set_flags(struct task_struct *task, unsigned long value)
 401 {
 402         struct pt_regs *regs = task_pt_regs(task);
 403
 404         /*
 405          * If the user value contains TF, mark that
 406          * it was not "us" (the debugger) that set it.
 407          * If not, make sure it stays set if we had.
 408          */
 409         if (value & X86_EFLAGS_TF)
 410                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
 411         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 412                 value |= X86_EFLAGS_TF;
 413
 414         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 415
 416         return 0;
 417 }
 418
 419 static int putreg(struct task_struct *child,
 420                   unsigned long offset, unsigned long value)
 421 {
 422         switch (offset) {
 423         case offsetof(struct user_regs_struct, cs):
 424         case offsetof(struct user_regs_struct, ds):
 425         case offsetof(struct user_regs_struct, es):
 426         case offsetof(struct user_regs_struct, fs):
 427         case offsetof(struct user_regs_struct, gs):
 428         case offsetof(struct user_regs_struct, ss):
 429                 return set_segment_reg(child, offset, value);
 430
 431         case offsetof(struct user_regs_struct, flags):
 432                 return set_flags(child, value);
 433
 434 #ifdef CONFIG_X86_64
 435         case offsetof(struct user_regs_struct,fs_base):
 436                 if (value >= TASK_SIZE_OF(child))
 437                         return -EIO;
 438                 /*
 439                  * When changing the segment base, use do_arch_prctl
 440                  * to set either thread.fs or thread.fsindex and the
 441                  * corresponding GDT slot.
 442                  */
 443                 if (child->thread.fs != value)
 444                         return do_arch_prctl(child, ARCH_SET_FS, value);
 445                 return 0;
 446         case offsetof(struct user_regs_struct,gs_base):
 447                 /*
 448                  * Exactly the same here as the %fs handling above.
 449                  */
 450                 if (value >= TASK_SIZE_OF(child))
 451                         return -EIO;
 452                 if (child->thread.gs != value)
 453                         return do_arch_prctl(child, ARCH_SET_GS, value);
 454                 return 0;
 455 #endif
 456         }
 457
 458         *pt_regs_access(task_pt_regs(child), offset) = value;
 459         return 0;
 460 }
 461
 462 static unsigned long getreg(struct task_struct *task, unsigned long offset)
 463 {
 464         switch (offset) {
 465         case offsetof(struct user_regs_struct, cs):
 466         case offsetof(struct user_regs_struct, ds):
 467         case offsetof(struct user_regs_struct, es):
 468         case offsetof(struct user_regs_struct, fs):
 469         case offsetof(struct user_regs_struct, gs):
 470         case offsetof(struct user_regs_struct, ss):
 471                 return get_segment_reg(task, offset);
 472
 473         case offsetof(struct user_regs_struct, flags):
 474                 return get_flags(task);
 475
 476 #ifdef CONFIG_X86_64
 477         case offsetof(struct user_regs_struct, fs_base): {
 478                 /*
 479                  * do_arch_prctl may have used a GDT slot instead of
 480                  * the MSR.  To userland, it appears the same either
 481                  * way, except the %fs segment selector might not be 0.
 482                  */
 483                 unsigned int seg = task->thread.fsindex;
 484                 if (task->thread.fs != 0)
 485                         return task->thread.fs;
 486                 if (task == current)
 487                         asm("movl %%fs,%0" : "=r" (seg));
 488                 if (seg != FS_TLS_SEL)
 489                         return 0;
 490                 return get_desc_base(&task->thread.tls_array[FS_TLS]);
 491         }
 492         case offsetof(struct user_regs_struct, gs_base): {
 493                 /*
 494                  * Exactly the same here as the %fs handling above.
 495                  */
 496                 unsigned int seg = task->thread.gsindex;
 497                 if (task->thread.gs != 0)
 498                         return task->thread.gs;
 499                 if (task == current)
 500                         asm("movl %%gs,%0" : "=r" (seg));
 501                 if (seg != GS_TLS_SEL)
 502                         return 0;
 503                 return get_desc_base(&task->thread.tls_array[GS_TLS]);
 504         }
 505 #endif
 506         }
 507
 508         return *pt_regs_access(task_pt_regs(task), offset);
 509 }
 510
 511 static int genregs_get(struct task_struct *target,
 512                        const struct user_regset *regset,
 513                        unsigned int pos, unsigned int count,
 514                        void *kbuf, void __user *ubuf)
 515 {
 516         if (kbuf) {
 517                 unsigned long *k = kbuf;
 518                 while (count >= sizeof(*k)) {
 519                         *k++ = getreg(target, pos);
 520                         count -= sizeof(*k);
 521                         pos += sizeof(*k);
 522                 }
 523         } else {
 524                 unsigned long __user *u = ubuf;
 525                 while (count >= sizeof(*u)) {
 526                         if (__put_user(getreg(target, pos), u++))
 527                                 return -EFAULT;
 528                         count -= sizeof(*u);
 529                         pos += sizeof(*u);
 530                 }
 531         }
 532
 533         return 0;
 534 }
 535
 536 static int genregs_set(struct task_struct *target,
 537                        const struct user_regset *regset,
 538                        unsigned int pos, unsigned int count,
 539                        const void *kbuf, const void __user *ubuf)
 540 {
 541         int ret = 0;
 542         if (kbuf) {
 543                 const unsigned long *k = kbuf;
 544                 while (count >= sizeof(*k) && !ret) {
 545                         ret = putreg(target, pos, *k++);
 546                         count -= sizeof(*k);
 547                         pos += sizeof(*k);
 548                 }
 549         } else {
 550                 const unsigned long  __user *u = ubuf;
 551                 while (count >= sizeof(*u) && !ret) {
 552                         unsigned long word;
 553                         ret = __get_user(word, u++);
 554                         if (ret)
 555                                 break;
 556                         ret = putreg(target, pos, word);
 557                         count -= sizeof(*u);
 558                         pos += sizeof(*u);
 559                 }
 560         }
 561         return ret;
 562 }
 563
 564 static void ptrace_triggered(struct perf_event *bp,
 565                              struct perf_sample_data *data,
 566                              struct pt_regs *regs)
 567 {
 568         int i;
 569         struct thread_struct *thread = &(current->thread);
 570
 571         /*
 572          * Store in the virtual DR6 register the fact that the breakpoint
 573          * was hit so the thread's debugger will see it.
 574          */
 575         for (i = 0; i < HBP_NUM; i++) {
 576                 if (thread->ptrace_bps[i] == bp)
 577                         break;
 578         }
 579
 580         thread->debugreg6 |= (DR_TRAP0 << i);
 581 }
 582
 583 /*
 584  * Walk through every ptrace breakpoints for this thread and
 585  * build the dr7 value on top of their attributes.
 586  *
 587  */
 588 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 589 {
 590         int i;
 591         int dr7 = 0;
 592         struct arch_hw_breakpoint *info;
 593
 594         for (i = 0; i < HBP_NUM; i++) {
 595                 if (bp[i] && !bp[i]->attr.disabled) {
 596                         info = counter_arch_bp(bp[i]);
 597                         dr7 |= encode_dr7(i, info->len, info->type);
 598                 }
 599         }
 600
 601         return dr7;
 602 }
 603
 604 static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
 605                                         int len, int type, bool disabled)
 606 {
 607         int err, bp_len, bp_type;
 608
 609         err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
 610         if (!err) {
 611                 attr->bp_len = bp_len;
 612                 attr->bp_type = bp_type;
 613                 attr->disabled = disabled;
 614         }
 615
 616         return err;
 617 }
 618
 619 static struct perf_event *
 620 ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
 621                                 unsigned long addr, bool disabled)
 622 {
 623         struct perf_event_attr attr;
 624         int err;
 625
 626         ptrace_breakpoint_init(&attr);
 627         attr.bp_addr = addr;
 628
 629         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 630         if (err)
 631                 return ERR_PTR(err);
 632
 633         return register_user_hw_breakpoint(&attr, ptrace_triggered,
 634                                                  NULL, tsk);
 635 }
 636
 637 static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 638                                         int disabled)
 639 {
 640         struct perf_event_attr attr = bp->attr;
 641         int err;
 642
 643         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
 644         if (err)
 645                 return err;
 646
 647         return modify_user_hw_breakpoint(bp, &attr);
 648 }
 649
 650 /*
 651  * Handle ptrace writes to debug register 7.
 652  */
 653 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 654 {
 655         struct thread_struct *thread = &tsk->thread;
 656         unsigned long old_dr7;
 657         bool second_pass = false;
 658         int i, rc, ret = 0;
 659
 660         data &= ~DR_CONTROL_RESERVED;
 661         old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 662
 663 restore:
 664         rc = 0;
 665         for (i = 0; i < HBP_NUM; i++) {
 666                 unsigned len, type;
 667                 bool disabled = !decode_dr7(data, i, &len, &type);
 668                 struct perf_event *bp = thread->ptrace_bps[i];
 669
 670                 if (!bp) {
 671                         if (disabled)
 672                                 continue;
 673                         /*
 674                          * We should have at least an inactive breakpoint at
 675                          * this slot. It means the user is writing dr7 without
 676                          * having written the address register first.
 677                          */
 678                         rc = -EINVAL;
 679                         break;
 680                 }
 681
 682                 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
 683                 if (rc)
 684                         break;
 685         }
 686
 687         /* Restore if the first pass failed, second_pass shouldn't fail. */
 688         if (rc && !WARN_ON(second_pass)) {
 689                 ret = rc;
 690                 data = old_dr7;
 691                 second_pass = true;
 692                 goto restore;
 693         }
 694
 695         return ret;
 696 }
 697
 698 /*
 699  * Handle PTRACE_PEEKUSR calls for the debug register area.
 700  */
 701 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 702 {
 703         struct thread_struct *thread = &(tsk->thread);
 704         unsigned long val = 0;
 705
 706         if (n < HBP_NUM) {
 707                 struct perf_event *bp = thread->ptrace_bps[n];
 708
 709                 if (bp)
 710                         val = bp->hw.info.address;
 711         } else if (n == 6) {
 712                 val = thread->debugreg6;
 713          } else if (n == 7) {
 714                 val = thread->ptrace_dr7;
 715         }
 716         return val;
 717 }
 718
 719 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 720                                       unsigned long addr)
 721 {
 722         struct thread_struct *t = &tsk->thread;
 723         struct perf_event *bp = t->ptrace_bps[nr];
 724         int err = 0;
 725
 726         if (!bp) {
 727                 /*
 728                  * Put stub len and type to create an inactive but correct bp.
 729                  *
 730                  * CHECKME: the previous code returned -EIO if the addr wasn't
 731                  * a valid task virtual addr. The new one will return -EINVAL in
 732                  *  this case.
 733                  * -EINVAL may be what we want for in-kernel breakpoints users,
 734                  * but -EIO looks better for ptrace, since we refuse a register
 735                  * writing for the user. And anyway this is the previous
 736                  * behaviour.
 737                  */
 738                 bp = ptrace_register_breakpoint(tsk,
 739                                 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
 740                                 addr, true);
 741                 if (IS_ERR(bp))
 742                         err = PTR_ERR(bp);
 743                 else
 744                         t->ptrace_bps[nr] = bp;
 745         } else {
 746                 struct perf_event_attr attr = bp->attr;
 747
 748                 attr.bp_addr = addr;
 749                 err = modify_user_hw_breakpoint(bp, &attr);
 750         }
 751
 752         return err;
 753 }
 754
 755 /*
 756  * Handle PTRACE_POKEUSR calls for the debug register area.
 757  */
 758 static int ptrace_set_debugreg(struct task_struct *tsk, int n,
 759                                unsigned long val)
 760 {
 761         struct thread_struct *thread = &(tsk->thread);
 762         int rc = 0;
 763
 764         /* There are no DR4 or DR5 registers */
 765         if (n == 4 || n == 5)
 766                 return -EIO;
 767
 768         if (n == 6) {
 769                 thread->debugreg6 = val;
 770                 goto ret_path;
 771         }
 772         if (n < HBP_NUM) {
 773                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
 774                 if (rc)
 775                         return rc;
 776         }
 777         /* All that's left is DR7 */
 778         if (n == 7) {
 779                 rc = ptrace_write_dr7(tsk, val);
 780                 if (!rc)
 781                         thread->ptrace_dr7 = val;
 782         }
 783
 784 ret_path:
 785         return rc;
 786 }
 787
 788 /*
 789  * These access the current or another (stopped) task's io permission
 790  * bitmap for debugging or core dump.
 791  */
 792 static int ioperm_active(struct task_struct *target,
 793                          const struct user_regset *regset)
 794 {
 795         return target->thread.io_bitmap_max / regset->size;
 796 }
 797
 798 static int ioperm_get(struct task_struct *target,
 799                       const struct user_regset *regset,
 800                       unsigned int pos, unsigned int count,
 801                       void *kbuf, void __user *ubuf)
 802 {
 803         if (!target->thread.io_bitmap_ptr)
 804                 return -ENXIO;
 805
 806         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 807                                    target->thread.io_bitmap_ptr,
 808                                    0, IO_BITMAP_BYTES);
 809 }
 810
 811 /*
 812  * Called by kernel/ptrace.c when detaching..
 813  *
 814  * Make sure the single step bit is not set.
 815  */
 816 void ptrace_disable(struct task_struct *child)
 817 {
 818         user_disable_single_step(child);
 819 #ifdef TIF_SYSCALL_EMU
 820         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 821 #endif
 822 }
 823
 824 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 825 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 826 #endif
 827
 828 long arch_ptrace(struct task_struct *child, long request,
 829                  unsigned long addr, unsigned long data)
 830 {
 831         int ret;
 832         unsigned long __user *datap = (unsigned long __user *)data;
 833
 834         switch (request) {
 835         /* read the word at location addr in the USER area. */
 836         case PTRACE_PEEKUSR: {
 837                 unsigned long tmp;
 838
 839                 ret = -EIO;
 840                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 841                         break;
 842
 843                 tmp = 0;  /* Default return condition */
 844                 if (addr < sizeof(struct user_regs_struct))
 845                         tmp = getreg(child, addr);
 846                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 847                          addr <= offsetof(struct user, u_debugreg[7])) {
 848                         addr -= offsetof(struct user, u_debugreg[0]);
 849                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 850                 }
 851                 ret = put_user(tmp, datap);
 852                 break;
 853         }
 854
 855         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 856                 ret = -EIO;
 857                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
 858                         break;
 859
 860                 if (addr < sizeof(struct user_regs_struct))
 861                         ret = putreg(child, addr, data);
 862                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 863                          addr <= offsetof(struct user, u_debugreg[7])) {
 864                         addr -= offsetof(struct user, u_debugreg[0]);
 865                         ret = ptrace_set_debugreg(child,
 866                                                   addr / sizeof(data), data);
 867                 }
 868                 break;
 869
 870         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 871                 return copy_regset_to_user(child,
 872                                            task_user_regset_view(current),
 873                                            REGSET_GENERAL,
 874                                            0, sizeof(struct user_regs_struct),
 875                                            datap);
 876
 877         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 878                 return copy_regset_from_user(child,
 879                                              task_user_regset_view(current),
 880                                              REGSET_GENERAL,
 881                                              0, sizeof(struct user_regs_struct),
 882                                              datap);
 883
 884         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 885                 return copy_regset_to_user(child,
 886                                            task_user_regset_view(current),
 887                                            REGSET_FP,
 888                                            0, sizeof(struct user_i387_struct),
 889                                            datap);
 890
 891         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
 892                 return copy_regset_from_user(child,
 893                                              task_user_regset_view(current),
 894                                              REGSET_FP,
 895                                              0, sizeof(struct user_i387_struct),
 896                                              datap);
 897
 898 #ifdef CONFIG_X86_32
 899         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
 900                 return copy_regset_to_user(child, &user_x86_32_view,
 901                                            REGSET_XFP,
 902                                            0, sizeof(struct user_fxsr_struct),
 903                                            datap) ? -EIO : 0;
 904
 905         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
 906                 return copy_regset_from_user(child, &user_x86_32_view,
 907                                              REGSET_XFP,
 908                                              0, sizeof(struct user_fxsr_struct),
 909                                              datap) ? -EIO : 0;
 910 #endif
 911
 912 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 913         case PTRACE_GET_THREAD_AREA:
 914                 if ((int) addr < 0)
 915                         return -EIO;
 916                 ret = do_get_thread_area(child, addr,
 917                                         (struct user_desc __user *)data);
 918                 break;
 919
 920         case PTRACE_SET_THREAD_AREA:
 921                 if ((int) addr < 0)
 922                         return -EIO;
 923                 ret = do_set_thread_area(child, addr,
 924                                         (struct user_desc __user *)data, 0);
 925                 break;
 926 #endif
 927
 928 #ifdef CONFIG_X86_64
 929                 /* normal 64bit interface to access TLS data.
 930                    Works just like arch_prctl, except that the arguments
 931                    are reversed. */
 932         case PTRACE_ARCH_PRCTL:
 933                 ret = do_arch_prctl(child, data, addr);
 934                 break;
 935 #endif
 936
 937         default:
 938                 ret = ptrace_request(child, request, addr, data);
 939                 break;
 940         }
 941
 942         return ret;
 943 }
 944
 945 #ifdef CONFIG_IA32_EMULATION
 946
 947 #include <linux/compat.h>
 948 #include <linux/syscalls.h>
 949 #include <asm/ia32.h>
 950 #include <asm/user32.h>
 951
 952 #define R32(l,q)                                                        \
 953         case offsetof(struct user32, regs.l):                           \
 954                 regs->q = value; break
 955
 956 #define SEG32(rs)                                                       \
 957         case offsetof(struct user32, regs.rs):                          \
 958                 return set_segment_reg(child,                           \
 959                                        offsetof(struct user_regs_struct, rs), \
 960                                        value);                          \
 961                 break
 962
 963 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 964 {
 965         struct pt_regs *regs = task_pt_regs(child);
 966
 967         switch (regno) {
 968
 969         SEG32(cs);
 970         SEG32(ds);
 971         SEG32(es);
 972         SEG32(fs);
 973         SEG32(gs);
 974         SEG32(ss);
 975
 976         R32(ebx, bx);
 977         R32(ecx, cx);
 978         R32(edx, dx);
 979         R32(edi, di);
 980         R32(esi, si);
 981         R32(ebp, bp);
 982         R32(eax, ax);
 983         R32(eip, ip);
 984         R32(esp, sp);
 985
 986         case offsetof(struct user32, regs.orig_eax):
 987                 /*
 988                  * A 32-bit debugger setting orig_eax means to restore
 989                  * the state of the task restarting a 32-bit syscall.
 990                  * Make sure we interpret the -ERESTART* codes correctly
 991                  * in case the task is not actually still sitting at the
 992                  * exit from a 32-bit syscall with TS_COMPAT still set.
 993                  */
 994                 regs->orig_ax = value;
 995                 if (syscall_get_nr(child, regs) >= 0)
 996                         task_thread_info(child)->status |= TS_COMPAT;
 997                 break;
 998
 999         case offsetof(struct user32, regs.eflags):
1000                 return set_flags(child, value);
1001
1002         case offsetof(struct user32, u_debugreg[0]) ...
1003                 offsetof(struct user32, u_debugreg[7]):
1004                 regno -= offsetof(struct user32, u_debugreg[0]);
1005                 return ptrace_set_debugreg(child, regno / 4, value);
1006
1007         default:
1008                 if (regno > sizeof(struct user32) || (regno & 3))
1009                         return -EIO;
1010
1011                 /*
1012                  * Other dummy fields in the virtual user structure
1013                  * are ignored
1014                  */
1015                 break;
1016         }
1017         return 0;
1018 }
1019
1020 #undef R32
1021 #undef SEG32
1022
1023 #define R32(l,q)                                                        \
1024         case offsetof(struct user32, regs.l):                           \
1025                 *val = regs->q; break
1026
1027 #define SEG32(rs)                                                       \
1028         case offsetof(struct user32, regs.rs):                          \
1029                 *val = get_segment_reg(child,                           \
1030                                        offsetof(struct user_regs_struct, rs)); \
1031                 break
1032
1033 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1034 {
1035         struct pt_regs *regs = task_pt_regs(child);
1036
1037         switch (regno) {
1038
1039         SEG32(ds);
1040         SEG32(es);
1041         SEG32(fs);
1042         SEG32(gs);
1043
1044         R32(cs, cs);
1045         R32(ss, ss);
1046         R32(ebx, bx);
1047         R32(ecx, cx);
1048         R32(edx, dx);
1049         R32(edi, di);
1050         R32(esi, si);
1051         R32(ebp, bp);
1052         R32(eax, ax);
1053         R32(orig_eax, orig_ax);
1054         R32(eip, ip);
1055         R32(esp, sp);
1056
1057         case offsetof(struct user32, regs.eflags):
1058                 *val = get_flags(child);
1059                 break;
1060
1061         case offsetof(struct user32, u_debugreg[0]) ...
1062                 offsetof(struct user32, u_debugreg[7]):
1063                 regno -= offsetof(struct user32, u_debugreg[0]);
1064                 *val = ptrace_get_debugreg(child, regno / 4);
1065                 break;
1066
1067         default:
1068                 if (regno > sizeof(struct user32) || (regno & 3))
1069                         return -EIO;
1070
1071                 /*
1072                  * Other dummy fields in the virtual user structure
1073                  * are ignored
1074                  */
1075                 *val = 0;
1076                 break;
1077         }
1078         return 0;
1079 }
1080
1081 #undef R32
1082 #undef SEG32
1083
1084 static int genregs32_get(struct task_struct *target,
1085                          const struct user_regset *regset,
1086                          unsigned int pos, unsigned int count,
1087                          void *kbuf, void __user *ubuf)
1088 {
1089         if (kbuf) {
1090                 compat_ulong_t *k = kbuf;
1091                 while (count >= sizeof(*k)) {
1092                         getreg32(target, pos, k++);
1093                         count -= sizeof(*k);
1094                         pos += sizeof(*k);
1095                 }
1096         } else {
1097                 compat_ulong_t __user *u = ubuf;
1098                 while (count >= sizeof(*u)) {
1099                         compat_ulong_t word;
1100                         getreg32(target, pos, &word);
1101                         if (__put_user(word, u++))
1102                                 return -EFAULT;
1103                         count -= sizeof(*u);
1104                         pos += sizeof(*u);
1105                 }
1106         }
1107
1108         return 0;
1109 }
1110
1111 static int genregs32_set(struct task_struct *target,
1112                          const struct user_regset *regset,
1113                          unsigned int pos, unsigned int count,
1114                          const void *kbuf, const void __user *ubuf)
1115 {
1116         int ret = 0;
1117         if (kbuf) {
1118                 const compat_ulong_t *k = kbuf;
1119                 while (count >= sizeof(*k) && !ret) {
1120                         ret = putreg32(target, pos, *k++);
1121                         count -= sizeof(*k);
1122                         pos += sizeof(*k);
1123                 }
1124         } else {
1125                 const compat_ulong_t __user *u = ubuf;
1126                 while (count >= sizeof(*u) && !ret) {
1127                         compat_ulong_t word;
1128                         ret = __get_user(word, u++);
1129                         if (ret)
1130                                 break;
1131                         ret = putreg32(target, pos, word);
1132                         count -= sizeof(*u);
1133                         pos += sizeof(*u);
1134                 }
1135         }
1136         return ret;
1137 }
1138
1139 #ifdef CONFIG_X86_X32_ABI
1140 static long x32_arch_ptrace(struct task_struct *child,
1141                             compat_long_t request, compat_ulong_t caddr,
1142                             compat_ulong_t cdata)
1143 {
1144         unsigned long addr = caddr;
1145         unsigned long data = cdata;
1146         void __user *datap = compat_ptr(data);
1147         int ret;
1148
1149         switch (request) {
1150         /* Read 32bits at location addr in the USER area.  Only allow
1151            to return the lower 32bits of segment and debug registers.  */
1152         case PTRACE_PEEKUSR: {
1153                 u32 tmp;
1154
1155                 ret = -EIO;
1156                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1157                     addr < offsetof(struct user_regs_struct, cs))
1158                         break;
1159
1160                 tmp = 0;  /* Default return condition */
1161                 if (addr < sizeof(struct user_regs_struct))
1162                         tmp = getreg(child, addr);
1163                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1164                          addr <= offsetof(struct user, u_debugreg[7])) {
1165                         addr -= offsetof(struct user, u_debugreg[0]);
1166                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1167                 }
1168                 ret = put_user(tmp, (__u32 __user *)datap);
1169                 break;
1170         }
1171
1172         /* Write the word at location addr in the USER area.  Only allow
1173            to update segment and debug registers with the upper 32bits
1174            zero-extended. */
1175         case PTRACE_POKEUSR:
1176                 ret = -EIO;
1177                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1178                     addr < offsetof(struct user_regs_struct, cs))
1179                         break;
1180
1181                 if (addr < sizeof(struct user_regs_struct))
1182                         ret = putreg(child, addr, data);
1183                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1184                          addr <= offsetof(struct user, u_debugreg[7])) {
1185                         addr -= offsetof(struct user, u_debugreg[0]);
1186                         ret = ptrace_set_debugreg(child,
1187                                                   addr / sizeof(data), data);
1188                 }
1189                 break;
1190
1191         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1192                 return copy_regset_to_user(child,
1193                                            task_user_regset_view(current),
1194                                            REGSET_GENERAL,
1195                                            0, sizeof(struct user_regs_struct),
1196                                            datap);
1197
1198         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1199                 return copy_regset_from_user(child,
1200                                              task_user_regset_view(current),
1201                                              REGSET_GENERAL,
1202                                              0, sizeof(struct user_regs_struct),
1203                                              datap);
1204
1205         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1206                 return copy_regset_to_user(child,
1207                                            task_user_regset_view(current),
1208                                            REGSET_FP,
1209                                            0, sizeof(struct user_i387_struct),
1210                                            datap);
1211
1212         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1213                 return copy_regset_from_user(child,
1214                                              task_user_regset_view(current),
1215                                              REGSET_FP,
1216                                              0, sizeof(struct user_i387_struct),
1217                                              datap);
1218
1219         default:
1220                 return compat_ptrace_request(child, request, addr, data);
1221         }
1222
1223         return ret;
1224 }
1225 #endif
1226
1227 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1228                         compat_ulong_t caddr, compat_ulong_t cdata)
1229 {
1230         unsigned long addr = caddr;
1231         unsigned long data = cdata;
1232         void __user *datap = compat_ptr(data);
1233         int ret;
1234         __u32 val;
1235
1236 #ifdef CONFIG_X86_X32_ABI
1237         if (!is_ia32_task())
1238                 return x32_arch_ptrace(child, request, caddr, cdata);
1239 #endif
1240
1241         switch (request) {
1242         case PTRACE_PEEKUSR:
1243                 ret = getreg32(child, addr, &val);
1244                 if (ret == 0)
1245                         ret = put_user(val, (__u32 __user *)datap);
1246                 break;
1247
1248         case PTRACE_POKEUSR:
1249                 ret = putreg32(child, addr, data);
1250                 break;
1251
1252         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1253                 return copy_regset_to_user(child, &user_x86_32_view,
1254                                            REGSET_GENERAL,
1255                                            0, sizeof(struct user_regs_struct32),
1256                                            datap);
1257
1258         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1259                 return copy_regset_from_user(child, &user_x86_32_view,
1260                                              REGSET_GENERAL, 0,
1261                                              sizeof(struct user_regs_struct32),
1262                                              datap);
1263
1264         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1265                 return copy_regset_to_user(child, &user_x86_32_view,
1266                                            REGSET_FP, 0,
1267                                            sizeof(struct user_i387_ia32_struct),
1268                                            datap);
1269
1270         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1271                 return copy_regset_from_user(
1272                         child, &user_x86_32_view, REGSET_FP,
1273                         0, sizeof(struct user_i387_ia32_struct), datap);
1274
1275         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1276                 return copy_regset_to_user(child, &user_x86_32_view,
1277                                            REGSET_XFP, 0,
1278                                            sizeof(struct user32_fxsr_struct),
1279                                            datap);
1280
1281         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1282                 return copy_regset_from_user(child, &user_x86_32_view,
1283                                              REGSET_XFP, 0,
1284                                              sizeof(struct user32_fxsr_struct),
1285                                              datap);
1286
1287         case PTRACE_GET_THREAD_AREA:
1288         case PTRACE_SET_THREAD_AREA:
1289                 return arch_ptrace(child, request, addr, data);
1290
1291         default:
1292                 return compat_ptrace_request(child, request, addr, data);
1293         }
1294
1295         return ret;
1296 }
1297
1298 #endif  /* CONFIG_IA32_EMULATION */
1299
1300 #ifdef CONFIG_X86_64
1301
1302 static struct user_regset x86_64_regsets[] __read_mostly = {
1303         [REGSET_GENERAL] = {
1304                 .core_note_type = NT_PRSTATUS,
1305                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1306                 .size = sizeof(long), .align = sizeof(long),
1307                 .get = genregs_get, .set = genregs_set
1308         },
1309         [REGSET_FP] = {
1310                 .core_note_type = NT_PRFPREG,
1311                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1312                 .size = sizeof(long), .align = sizeof(long),
1313                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1314         },
1315         [REGSET_XSTATE] = {
1316                 .core_note_type = NT_X86_XSTATE,
1317                 .size = sizeof(u64), .align = sizeof(u64),
1318                 .active = xstateregs_active, .get = xstateregs_get,
1319                 .set = xstateregs_set
1320         },
1321         [REGSET_IOPERM64] = {
1322                 .core_note_type = NT_386_IOPERM,
1323                 .n = IO_BITMAP_LONGS,
1324                 .size = sizeof(long), .align = sizeof(long),
1325                 .active = ioperm_active, .get = ioperm_get
1326         },
1327 };
1328
1329 static const struct user_regset_view user_x86_64_view = {
1330         .name = "x86_64", .e_machine = EM_X86_64,
1331         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1332 };
1333
1334 #else  /* CONFIG_X86_32 */
1335
1336 #define user_regs_struct32      user_regs_struct
1337 #define genregs32_get           genregs_get
1338 #define genregs32_set           genregs_set
1339
1340 #endif  /* CONFIG_X86_64 */
1341
1342 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1343 static struct user_regset x86_32_regsets[] __read_mostly = {
1344         [REGSET_GENERAL] = {
1345                 .core_note_type = NT_PRSTATUS,
1346                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1347                 .size = sizeof(u32), .align = sizeof(u32),
1348                 .get = genregs32_get, .set = genregs32_set
1349         },
1350         [REGSET_FP] = {
1351                 .core_note_type = NT_PRFPREG,
1352                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1353                 .size = sizeof(u32), .align = sizeof(u32),
1354                 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1355         },
1356         [REGSET_XFP] = {
1357                 .core_note_type = NT_PRXFPREG,
1358                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1359                 .size = sizeof(u32), .align = sizeof(u32),
1360                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1361         },
1362         [REGSET_XSTATE] = {
1363                 .core_note_type = NT_X86_XSTATE,
1364                 .size = sizeof(u64), .align = sizeof(u64),
1365                 .active = xstateregs_active, .get = xstateregs_get,
1366                 .set = xstateregs_set
1367         },
1368         [REGSET_TLS] = {
1369                 .core_note_type = NT_386_TLS,
1370                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1371                 .size = sizeof(struct user_desc),
1372                 .align = sizeof(struct user_desc),
1373                 .active = regset_tls_active,
1374                 .get = regset_tls_get, .set = regset_tls_set
1375         },
1376         [REGSET_IOPERM32] = {
1377                 .core_note_type = NT_386_IOPERM,
1378                 .n = IO_BITMAP_BYTES / sizeof(u32),
1379                 .size = sizeof(u32), .align = sizeof(u32),
1380                 .active = ioperm_active, .get = ioperm_get
1381         },
1382 };
1383
1384 static const struct user_regset_view user_x86_32_view = {
1385         .name = "i386", .e_machine = EM_386,
1386         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1387 };
1388 #endif
1389
1390 /*
1391  * This represents bytes 464..511 in the memory layout exported through
1392  * the REGSET_XSTATE interface.
1393  */
1394 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1395
1396 void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1397 {
1398 #ifdef CONFIG_X86_64
1399         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1400 #endif
1401 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1402         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1403 #endif
1404         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1405 }
1406
1407 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1408 {
1409 #ifdef CONFIG_IA32_EMULATION
1410         if (test_tsk_thread_flag(task, TIF_IA32))
1411 #endif
1412 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1413                 return &user_x86_32_view;
1414 #endif
1415 #ifdef CONFIG_X86_64
1416         return &user_x86_64_view;
1417 #endif
1418 }
1419
1420 static void fill_sigtrap_info(struct task_struct *tsk,
1421                                 struct pt_regs *regs,
1422                                 int error_code, int si_code,
1423                                 struct siginfo *info)
1424 {
1425         tsk->thread.trap_nr = X86_TRAP_DB;
1426         tsk->thread.error_code = error_code;
1427
1428         memset(info, 0, sizeof(*info));
1429         info->si_signo = SIGTRAP;
1430         info->si_code = si_code;
1431         info->si_addr = user_mode_vm(regs) ? (void __user *)regs->ip : NULL;
1432 }
1433
1434 void user_single_step_siginfo(struct task_struct *tsk,
1435                                 struct pt_regs *regs,
1436                                 struct siginfo *info)
1437 {
1438         fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1439 }
1440
1441 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1442                                          int error_code, int si_code)
1443 {
1444         struct siginfo info;
1445
1446         fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1447         /* Send us the fake SIGTRAP */
1448         force_sig_info(SIGTRAP, &info, tsk);
1449 }
1450
1451
1452 #ifdef CONFIG_X86_32
1453 # define IS_IA32        1
1454 #elif defined CONFIG_IA32_EMULATION
1455 # define IS_IA32        is_compat_task()
1456 #else
1457 # define IS_IA32        0
1458 #endif
1459
1460 /*
1461  * We must return the syscall number to actually look up in the table.
1462  * This can be -1L to skip running any syscall at all.
1463  */
1464 long syscall_trace_enter(struct pt_regs *regs)
1465 {
1466         long ret = 0;
1467
1468         user_exit();
1469
1470         /*
1471          * If we stepped into a sysenter/syscall insn, it trapped in
1472          * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1473          * If user-mode had set TF itself, then it's still clear from
1474          * do_debug() and we need to set it again to restore the user
1475          * state.  If we entered on the slow path, TF was already set.
1476          */
1477         if (test_thread_flag(TIF_SINGLESTEP))
1478                 regs->flags |= X86_EFLAGS_TF;
1479
1480         /* do the secure computing check first */
1481         if (secure_computing(regs->orig_ax)) {
1482                 /* seccomp failures shouldn't expose any additional code. */
1483                 ret = -1L;
1484                 goto out;
1485         }
1486
1487         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1488                 ret = -1L;
1489
1490         if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1491             tracehook_report_syscall_entry(regs))
1492                 ret = -1L;
1493
1494         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1495                 trace_sys_enter(regs, regs->orig_ax);
1496
1497         if (IS_IA32)
1498                 audit_syscall_entry(AUDIT_ARCH_I386,
1499                                     regs->orig_ax,
1500                                     regs->bx, regs->cx,
1501                                     regs->dx, regs->si);
1502 #ifdef CONFIG_X86_64
1503         else
1504                 audit_syscall_entry(AUDIT_ARCH_X86_64,
1505                                     regs->orig_ax,
1506                                     regs->di, regs->si,
1507                                     regs->dx, regs->r10);
1508 #endif
1509
1510 out:
1511         return ret ?: regs->orig_ax;
1512 }
1513
1514 void syscall_trace_leave(struct pt_regs *regs)
1515 {
1516         bool step;
1517
1518         /*
1519          * We may come here right after calling schedule_user()
1520          * or do_notify_resume(), in which case we can be in RCU
1521          * user mode.
1522          */
1523         user_exit();
1524
1525         audit_syscall_exit(regs);
1526
1527         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1528                 trace_sys_exit(regs, regs->ax);
1529
1530         /*
1531          * If TIF_SYSCALL_EMU is set, we only get here because of
1532          * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1533          * We already reported this syscall instruction in
1534          * syscall_trace_enter().
1535          */
1536         step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
1537                         !test_thread_flag(TIF_SYSCALL_EMU);
1538         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1539                 tracehook_report_syscall_exit(regs, step);
1540
1541         user_enter();
1542 }