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  * BTS tracing
   7  *      Markus Metzger <markus.t.metzger@intel.com>, Dec 2007
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/sched.h>
  12 #include <linux/mm.h>
  13 #include <linux/smp.h>
  14 #include <linux/errno.h>
  15 #include <linux/ptrace.h>
  16 #include <linux/regset.h>
  17 #include <linux/tracehook.h>
  18 #include <linux/user.h>
  19 #include <linux/elf.h>
  20 #include <linux/security.h>
  21 #include <linux/audit.h>
  22 #include <linux/seccomp.h>
  23 #include <linux/signal.h>
  24 #include <linux/workqueue.h>
  25
  26 #include <asm/uaccess.h>
  27 #include <asm/pgtable.h>
  28 #include <asm/system.h>
  29 #include <asm/processor.h>
  30 #include <asm/i387.h>
  31 #include <asm/debugreg.h>
  32 #include <asm/ldt.h>
  33 #include <asm/desc.h>
  34 #include <asm/prctl.h>
  35 #include <asm/proto.h>
  36 #include <asm/ds.h>
  37
  38 #include "tls.h"
  39
  40 #define CREATE_TRACE_POINTS
  41 #include <trace/events/syscalls.h>
  42
  43 enum x86_regset {
  44         REGSET_GENERAL,
  45         REGSET_FP,
  46         REGSET_XFP,
  47         REGSET_IOPERM64 = REGSET_XFP,
  48         REGSET_TLS,
  49         REGSET_IOPERM32,
  50 };
  51
  52 /*
  53  * does not yet catch signals sent when the child dies.
  54  * in exit.c or in signal.c.
  55  */
  56
  57 /*
  58  * Determines which flags the user has access to [1 = access, 0 = no access].
  59  */
  60 #define FLAG_MASK_32            ((unsigned long)                        \
  61                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
  62                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
  63                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
  64                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
  65                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
  66
  67 /*
  68  * Determines whether a value may be installed in a segment register.
  69  */
  70 static inline bool invalid_selector(u16 value)
  71 {
  72         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
  73 }
  74
  75 #ifdef CONFIG_X86_32
  76
  77 #define FLAG_MASK               FLAG_MASK_32
  78
  79 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
  80 {
  81         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
  82         return &regs->bx + (regno >> 2);
  83 }
  84
  85 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
  86 {
  87         /*
  88          * Returning the value truncates it to 16 bits.
  89          */
  90         unsigned int retval;
  91         if (offset != offsetof(struct user_regs_struct, gs))
  92                 retval = *pt_regs_access(task_pt_regs(task), offset);
  93         else {
  94                 if (task == current)
  95                         retval = get_user_gs(task_pt_regs(task));
  96                 else
  97                         retval = task_user_gs(task);
  98         }
  99         return retval;
 100 }
 101
 102 static int set_segment_reg(struct task_struct *task,
 103                            unsigned long offset, u16 value)
 104 {
 105         /*
 106          * The value argument was already truncated to 16 bits.
 107          */
 108         if (invalid_selector(value))
 109                 return -EIO;
 110
 111         /*
 112          * For %cs and %ss we cannot permit a null selector.
 113          * We can permit a bogus selector as long as it has USER_RPL.
 114          * Null selectors are fine for other segment registers, but
 115          * we will never get back to user mode with invalid %cs or %ss
 116          * and will take the trap in iret instead.  Much code relies
 117          * on user_mode() to distinguish a user trap frame (which can
 118          * safely use invalid selectors) from a kernel trap frame.
 119          */
 120         switch (offset) {
 121         case offsetof(struct user_regs_struct, cs):
 122         case offsetof(struct user_regs_struct, ss):
 123                 if (unlikely(value == 0))
 124                         return -EIO;
 125
 126         default:
 127                 *pt_regs_access(task_pt_regs(task), offset) = value;
 128                 break;
 129
 130         case offsetof(struct user_regs_struct, gs):
 131                 if (task == current)
 132                         set_user_gs(task_pt_regs(task), value);
 133                 else
 134                         task_user_gs(task) = value;
 135         }
 136
 137         return 0;
 138 }
 139
 140 static unsigned long debugreg_addr_limit(struct task_struct *task)
 141 {
 142         return TASK_SIZE - 3;
 143 }
 144
 145 #else  /* CONFIG_X86_64 */
 146
 147 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
 148
 149 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 150 {
 151         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 152         return &regs->r15 + (offset / sizeof(regs->r15));
 153 }
 154
 155 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 156 {
 157         /*
 158          * Returning the value truncates it to 16 bits.
 159          */
 160         unsigned int seg;
 161
 162         switch (offset) {
 163         case offsetof(struct user_regs_struct, fs):
 164                 if (task == current) {
 165                         /* Older gas can't assemble movq %?s,%r?? */
 166                         asm("movl %%fs,%0" : "=r" (seg));
 167                         return seg;
 168                 }
 169                 return task->thread.fsindex;
 170         case offsetof(struct user_regs_struct, gs):
 171                 if (task == current) {
 172                         asm("movl %%gs,%0" : "=r" (seg));
 173                         return seg;
 174                 }
 175                 return task->thread.gsindex;
 176         case offsetof(struct user_regs_struct, ds):
 177                 if (task == current) {
 178                         asm("movl %%ds,%0" : "=r" (seg));
 179                         return seg;
 180                 }
 181                 return task->thread.ds;
 182         case offsetof(struct user_regs_struct, es):
 183                 if (task == current) {
 184                         asm("movl %%es,%0" : "=r" (seg));
 185                         return seg;
 186                 }
 187                 return task->thread.es;
 188
 189         case offsetof(struct user_regs_struct, cs):
 190         case offsetof(struct user_regs_struct, ss):
 191                 break;
 192         }
 193         return *pt_regs_access(task_pt_regs(task), offset);
 194 }
 195
 196 static int set_segment_reg(struct task_struct *task,
 197                            unsigned long offset, u16 value)
 198 {
 199         /*
 200          * The value argument was already truncated to 16 bits.
 201          */
 202         if (invalid_selector(value))
 203                 return -EIO;
 204
 205         switch (offset) {
 206         case offsetof(struct user_regs_struct,fs):
 207                 /*
 208                  * If this is setting fs as for normal 64-bit use but
 209                  * setting fs_base has implicitly changed it, leave it.
 210                  */
 211                 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
 212                      task->thread.fs != 0) ||
 213                     (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
 214                      task->thread.fs == 0))
 215                         break;
 216                 task->thread.fsindex = value;
 217                 if (task == current)
 218                         loadsegment(fs, task->thread.fsindex);
 219                 break;
 220         case offsetof(struct user_regs_struct,gs):
 221                 /*
 222                  * If this is setting gs as for normal 64-bit use but
 223                  * setting gs_base has implicitly changed it, leave it.
 224                  */
 225                 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
 226                      task->thread.gs != 0) ||
 227                     (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
 228                      task->thread.gs == 0))
 229                         break;
 230                 task->thread.gsindex = value;
 231                 if (task == current)
 232                         load_gs_index(task->thread.gsindex);
 233                 break;
 234         case offsetof(struct user_regs_struct,ds):
 235                 task->thread.ds = value;
 236                 if (task == current)
 237                         loadsegment(ds, task->thread.ds);
 238                 break;
 239         case offsetof(struct user_regs_struct,es):
 240                 task->thread.es = value;
 241                 if (task == current)
 242                         loadsegment(es, task->thread.es);
 243                 break;
 244
 245                 /*
 246                  * Can't actually change these in 64-bit mode.
 247                  */
 248         case offsetof(struct user_regs_struct,cs):
 249                 if (unlikely(value == 0))
 250                         return -EIO;
 251 #ifdef CONFIG_IA32_EMULATION
 252                 if (test_tsk_thread_flag(task, TIF_IA32))
 253                         task_pt_regs(task)->cs = value;
 254 #endif
 255                 break;
 256         case offsetof(struct user_regs_struct,ss):
 257                 if (unlikely(value == 0))
 258                         return -EIO;
 259 #ifdef CONFIG_IA32_EMULATION
 260                 if (test_tsk_thread_flag(task, TIF_IA32))
 261                         task_pt_regs(task)->ss = value;
 262 #endif
 263                 break;
 264         }
 265
 266         return 0;
 267 }
 268
 269 static unsigned long debugreg_addr_limit(struct task_struct *task)
 270 {
 271 #ifdef CONFIG_IA32_EMULATION
 272         if (test_tsk_thread_flag(task, TIF_IA32))
 273                 return IA32_PAGE_OFFSET - 3;
 274 #endif
 275         return TASK_SIZE_MAX - 7;
 276 }
 277
 278 #endif  /* CONFIG_X86_32 */
 279
 280 static unsigned long get_flags(struct task_struct *task)
 281 {
 282         unsigned long retval = task_pt_regs(task)->flags;
 283
 284         /*
 285          * If the debugger set TF, hide it from the readout.
 286          */
 287         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 288                 retval &= ~X86_EFLAGS_TF;
 289
 290         return retval;
 291 }
 292
 293 static int set_flags(struct task_struct *task, unsigned long value)
 294 {
 295         struct pt_regs *regs = task_pt_regs(task);
 296
 297         /*
 298          * If the user value contains TF, mark that
 299          * it was not "us" (the debugger) that set it.
 300          * If not, make sure it stays set if we had.
 301          */
 302         if (value & X86_EFLAGS_TF)
 303                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
 304         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 305                 value |= X86_EFLAGS_TF;
 306
 307         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 308
 309         return 0;
 310 }
 311
 312 static int putreg(struct task_struct *child,
 313                   unsigned long offset, unsigned long value)
 314 {
 315         switch (offset) {
 316         case offsetof(struct user_regs_struct, cs):
 317         case offsetof(struct user_regs_struct, ds):
 318         case offsetof(struct user_regs_struct, es):
 319         case offsetof(struct user_regs_struct, fs):
 320         case offsetof(struct user_regs_struct, gs):
 321         case offsetof(struct user_regs_struct, ss):
 322                 return set_segment_reg(child, offset, value);
 323
 324         case offsetof(struct user_regs_struct, flags):
 325                 return set_flags(child, value);
 326
 327 #ifdef CONFIG_X86_64
 328         /*
 329          * Orig_ax is really just a flag with small positive and
 330          * negative values, so make sure to always sign-extend it
 331          * from 32 bits so that it works correctly regardless of
 332          * whether we come from a 32-bit environment or not.
 333          */
 334         case offsetof(struct user_regs_struct, orig_ax):
 335                 value = (long) (s32) value;
 336                 break;
 337
 338         case offsetof(struct user_regs_struct,fs_base):
 339                 if (value >= TASK_SIZE_OF(child))
 340                         return -EIO;
 341                 /*
 342                  * When changing the segment base, use do_arch_prctl
 343                  * to set either thread.fs or thread.fsindex and the
 344                  * corresponding GDT slot.
 345                  */
 346                 if (child->thread.fs != value)
 347                         return do_arch_prctl(child, ARCH_SET_FS, value);
 348                 return 0;
 349         case offsetof(struct user_regs_struct,gs_base):
 350                 /*
 351                  * Exactly the same here as the %fs handling above.
 352                  */
 353                 if (value >= TASK_SIZE_OF(child))
 354                         return -EIO;
 355                 if (child->thread.gs != value)
 356                         return do_arch_prctl(child, ARCH_SET_GS, value);
 357                 return 0;
 358 #endif
 359         }
 360
 361         *pt_regs_access(task_pt_regs(child), offset) = value;
 362         return 0;
 363 }
 364
 365 static unsigned long getreg(struct task_struct *task, unsigned long offset)
 366 {
 367         switch (offset) {
 368         case offsetof(struct user_regs_struct, cs):
 369         case offsetof(struct user_regs_struct, ds):
 370         case offsetof(struct user_regs_struct, es):
 371         case offsetof(struct user_regs_struct, fs):
 372         case offsetof(struct user_regs_struct, gs):
 373         case offsetof(struct user_regs_struct, ss):
 374                 return get_segment_reg(task, offset);
 375
 376         case offsetof(struct user_regs_struct, flags):
 377                 return get_flags(task);
 378
 379 #ifdef CONFIG_X86_64
 380         case offsetof(struct user_regs_struct, fs_base): {
 381                 /*
 382                  * do_arch_prctl may have used a GDT slot instead of
 383                  * the MSR.  To userland, it appears the same either
 384                  * way, except the %fs segment selector might not be 0.
 385                  */
 386                 unsigned int seg = task->thread.fsindex;
 387                 if (task->thread.fs != 0)
 388                         return task->thread.fs;
 389                 if (task == current)
 390                         asm("movl %%fs,%0" : "=r" (seg));
 391                 if (seg != FS_TLS_SEL)
 392                         return 0;
 393                 return get_desc_base(&task->thread.tls_array[FS_TLS]);
 394         }
 395         case offsetof(struct user_regs_struct, gs_base): {
 396                 /*
 397                  * Exactly the same here as the %fs handling above.
 398                  */
 399                 unsigned int seg = task->thread.gsindex;
 400                 if (task->thread.gs != 0)
 401                         return task->thread.gs;
 402                 if (task == current)
 403                         asm("movl %%gs,%0" : "=r" (seg));
 404                 if (seg != GS_TLS_SEL)
 405                         return 0;
 406                 return get_desc_base(&task->thread.tls_array[GS_TLS]);
 407         }
 408 #endif
 409         }
 410
 411         return *pt_regs_access(task_pt_regs(task), offset);
 412 }
 413
 414 static int genregs_get(struct task_struct *target,
 415                        const struct user_regset *regset,
 416                        unsigned int pos, unsigned int count,
 417                        void *kbuf, void __user *ubuf)
 418 {
 419         if (kbuf) {
 420                 unsigned long *k = kbuf;
 421                 while (count > 0) {
 422                         *k++ = getreg(target, pos);
 423                         count -= sizeof(*k);
 424                         pos += sizeof(*k);
 425                 }
 426         } else {
 427                 unsigned long __user *u = ubuf;
 428                 while (count > 0) {
 429                         if (__put_user(getreg(target, pos), u++))
 430                                 return -EFAULT;
 431                         count -= sizeof(*u);
 432                         pos += sizeof(*u);
 433                 }
 434         }
 435
 436         return 0;
 437 }
 438
 439 static int genregs_set(struct task_struct *target,
 440                        const struct user_regset *regset,
 441                        unsigned int pos, unsigned int count,
 442                        const void *kbuf, const void __user *ubuf)
 443 {
 444         int ret = 0;
 445         if (kbuf) {
 446                 const unsigned long *k = kbuf;
 447                 while (count > 0 && !ret) {
 448                         ret = putreg(target, pos, *k++);
 449                         count -= sizeof(*k);
 450                         pos += sizeof(*k);
 451                 }
 452         } else {
 453                 const unsigned long  __user *u = ubuf;
 454                 while (count > 0 && !ret) {
 455                         unsigned long word;
 456                         ret = __get_user(word, u++);
 457                         if (ret)
 458                                 break;
 459                         ret = putreg(target, pos, word);
 460                         count -= sizeof(*u);
 461                         pos += sizeof(*u);
 462                 }
 463         }
 464         return ret;
 465 }
 466
 467 /*
 468  * This function is trivial and will be inlined by the compiler.
 469  * Having it separates the implementation details of debug
 470  * registers from the interface details of ptrace.
 471  */
 472 static unsigned long ptrace_get_debugreg(struct task_struct *child, int n)
 473 {
 474         switch (n) {
 475         case 0:         return child->thread.debugreg0;
 476         case 1:         return child->thread.debugreg1;
 477         case 2:         return child->thread.debugreg2;
 478         case 3:         return child->thread.debugreg3;
 479         case 6:         return child->thread.debugreg6;
 480         case 7:         return child->thread.debugreg7;
 481         }
 482         return 0;
 483 }
 484
 485 static int ptrace_set_debugreg(struct task_struct *child,
 486                                int n, unsigned long data)
 487 {
 488         int i;
 489
 490         if (unlikely(n == 4 || n == 5))
 491                 return -EIO;
 492
 493         if (n < 4 && unlikely(data >= debugreg_addr_limit(child)))
 494                 return -EIO;
 495
 496         switch (n) {
 497         case 0:         child->thread.debugreg0 = data; break;
 498         case 1:         child->thread.debugreg1 = data; break;
 499         case 2:         child->thread.debugreg2 = data; break;
 500         case 3:         child->thread.debugreg3 = data; break;
 501
 502         case 6:
 503                 if ((data & ~0xffffffffUL) != 0)
 504                         return -EIO;
 505                 child->thread.debugreg6 = data;
 506                 break;
 507
 508         case 7:
 509                 /*
 510                  * Sanity-check data. Take one half-byte at once with
 511                  * check = (val >> (16 + 4*i)) & 0xf. It contains the
 512                  * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits
 513                  * 2 and 3 are LENi. Given a list of invalid values,
 514                  * we do mask |= 1 << invalid_value, so that
 515                  * (mask >> check) & 1 is a correct test for invalid
 516                  * values.
 517                  *
 518                  * R/Wi contains the type of the breakpoint /
 519                  * watchpoint, LENi contains the length of the watched
 520                  * data in the watchpoint case.
 521                  *
 522                  * The invalid values are:
 523                  * - LENi == 0x10 (undefined), so mask |= 0x0f00.       [32-bit]
 524                  * - R/Wi == 0x10 (break on I/O reads or writes), so
 525                  *   mask |= 0x4444.
 526                  * - R/Wi == 0x00 && LENi != 0x00, so we have mask |=
 527                  *   0x1110.
 528                  *
 529                  * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54.
 530                  *
 531                  * See the Intel Manual "System Programming Guide",
 532                  * 15.2.4
 533                  *
 534                  * Note that LENi == 0x10 is defined on x86_64 in long
 535                  * mode (i.e. even for 32-bit userspace software, but
 536                  * 64-bit kernel), so the x86_64 mask value is 0x5454.
 537                  * See the AMD manual no. 24593 (AMD64 System Programming)
 538                  */
 539 #ifdef CONFIG_X86_32
 540 #define DR7_MASK        0x5f54
 541 #else
 542 #define DR7_MASK        0x5554
 543 #endif
 544                 data &= ~DR_CONTROL_RESERVED;
 545                 for (i = 0; i < 4; i++)
 546                         if ((DR7_MASK >> ((data >> (16 + 4*i)) & 0xf)) & 1)
 547                                 return -EIO;
 548                 child->thread.debugreg7 = data;
 549                 if (data)
 550                         set_tsk_thread_flag(child, TIF_DEBUG);
 551                 else
 552                         clear_tsk_thread_flag(child, TIF_DEBUG);
 553                 break;
 554         }
 555
 556         return 0;
 557 }
 558
 559 /*
 560  * These access the current or another (stopped) task's io permission
 561  * bitmap for debugging or core dump.
 562  */
 563 static int ioperm_active(struct task_struct *target,
 564                          const struct user_regset *regset)
 565 {
 566         return target->thread.io_bitmap_max / regset->size;
 567 }
 568
 569 static int ioperm_get(struct task_struct *target,
 570                       const struct user_regset *regset,
 571                       unsigned int pos, unsigned int count,
 572                       void *kbuf, void __user *ubuf)
 573 {
 574         if (!target->thread.io_bitmap_ptr)
 575                 return -ENXIO;
 576
 577         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 578                                    target->thread.io_bitmap_ptr,
 579                                    0, IO_BITMAP_BYTES);
 580 }
 581
 582 #ifdef CONFIG_X86_PTRACE_BTS
 583 /*
 584  * A branch trace store context.
 585  *
 586  * Contexts may only be installed by ptrace_bts_config() and only for
 587  * ptraced tasks.
 588  *
 589  * Contexts are destroyed when the tracee is detached from the tracer.
 590  * The actual destruction work requires interrupts enabled, so the
 591  * work is deferred and will be scheduled during __ptrace_unlink().
 592  *
 593  * Contexts hold an additional task_struct reference on the traced
 594  * task, as well as a reference on the tracer's mm.
 595  *
 596  * Ptrace already holds a task_struct for the duration of ptrace operations,
 597  * but since destruction is deferred, it may be executed after both
 598  * tracer and tracee exited.
 599  */
 600 struct bts_context {
 601         /* The branch trace handle. */
 602         struct bts_tracer       *tracer;
 603
 604         /* The buffer used to store the branch trace and its size. */
 605         void                    *buffer;
 606         unsigned int            size;
 607
 608         /* The mm that paid for the above buffer. */
 609         struct mm_struct        *mm;
 610
 611         /* The task this context belongs to. */
 612         struct task_struct      *task;
 613
 614         /* The signal to send on a bts buffer overflow. */
 615         unsigned int            bts_ovfl_signal;
 616
 617         /* The work struct to destroy a context. */
 618         struct work_struct      work;
 619 };
 620
 621 static int alloc_bts_buffer(struct bts_context *context, unsigned int size)
 622 {
 623         void *buffer = NULL;
 624         int err = -ENOMEM;
 625
 626         err = account_locked_memory(current->mm, current->signal->rlim, size);
 627         if (err < 0)
 628                 return err;
 629
 630         buffer = kzalloc(size, GFP_KERNEL);
 631         if (!buffer)
 632                 goto out_refund;
 633
 634         context->buffer = buffer;
 635         context->size = size;
 636         context->mm = get_task_mm(current);
 637
 638         return 0;
 639
 640  out_refund:
 641         refund_locked_memory(current->mm, size);
 642         return err;
 643 }
 644
 645 static inline void free_bts_buffer(struct bts_context *context)
 646 {
 647         if (!context->buffer)
 648                 return;
 649
 650         kfree(context->buffer);
 651         context->buffer = NULL;
 652
 653         refund_locked_memory(context->mm, context->size);
 654         context->size = 0;
 655
 656         mmput(context->mm);
 657         context->mm = NULL;
 658 }
 659
 660 static void free_bts_context_work(struct work_struct *w)
 661 {
 662         struct bts_context *context;
 663
 664         context = container_of(w, struct bts_context, work);
 665
 666         ds_release_bts(context->tracer);
 667         put_task_struct(context->task);
 668         free_bts_buffer(context);
 669         kfree(context);
 670 }
 671
 672 static inline void free_bts_context(struct bts_context *context)
 673 {
 674         INIT_WORK(&context->work, free_bts_context_work);
 675         schedule_work(&context->work);
 676 }
 677
 678 static inline struct bts_context *alloc_bts_context(struct task_struct *task)
 679 {
 680         struct bts_context *context = kzalloc(sizeof(*context), GFP_KERNEL);
 681         if (context) {
 682                 context->task = task;
 683                 task->bts = context;
 684
 685                 get_task_struct(task);
 686         }
 687
 688         return context;
 689 }
 690
 691 static int ptrace_bts_read_record(struct task_struct *child, size_t index,
 692                                   struct bts_struct __user *out)
 693 {
 694         struct bts_context *context;
 695         const struct bts_trace *trace;
 696         struct bts_struct bts;
 697         const unsigned char *at;
 698         int error;
 699
 700         context = child->bts;
 701         if (!context)
 702                 return -ESRCH;
 703
 704         trace = ds_read_bts(context->tracer);
 705         if (!trace)
 706                 return -ESRCH;
 707
 708         at = trace->ds.top - ((index + 1) * trace->ds.size);
 709         if ((void *)at < trace->ds.begin)
 710                 at += (trace->ds.n * trace->ds.size);
 711
 712         if (!trace->read)
 713                 return -EOPNOTSUPP;
 714
 715         error = trace->read(context->tracer, at, &bts);
 716         if (error < 0)
 717                 return error;
 718
 719         if (copy_to_user(out, &bts, sizeof(bts)))
 720                 return -EFAULT;
 721
 722         return sizeof(bts);
 723 }
 724
 725 static int ptrace_bts_drain(struct task_struct *child,
 726                             long size,
 727                             struct bts_struct __user *out)
 728 {
 729         struct bts_context *context;
 730         const struct bts_trace *trace;
 731         const unsigned char *at;
 732         int error, drained = 0;
 733
 734         context = child->bts;
 735         if (!context)
 736                 return -ESRCH;
 737
 738         trace = ds_read_bts(context->tracer);
 739         if (!trace)
 740                 return -ESRCH;
 741
 742         if (!trace->read)
 743                 return -EOPNOTSUPP;
 744
 745         if (size < (trace->ds.top - trace->ds.begin))
 746                 return -EIO;
 747
 748         for (at = trace->ds.begin; (void *)at < trace->ds.top;
 749              out++, drained++, at += trace->ds.size) {
 750                 struct bts_struct bts;
 751
 752                 error = trace->read(context->tracer, at, &bts);
 753                 if (error < 0)
 754                         return error;
 755
 756                 if (copy_to_user(out, &bts, sizeof(bts)))
 757                         return -EFAULT;
 758         }
 759
 760         memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
 761
 762         error = ds_reset_bts(context->tracer);
 763         if (error < 0)
 764                 return error;
 765
 766         return drained;
 767 }
 768
 769 static int ptrace_bts_config(struct task_struct *child,
 770                              long cfg_size,
 771                              const struct ptrace_bts_config __user *ucfg)
 772 {
 773         struct bts_context *context;
 774         struct ptrace_bts_config cfg;
 775         unsigned int flags = 0;
 776
 777         if (cfg_size < sizeof(cfg))
 778                 return -EIO;
 779
 780         if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
 781                 return -EFAULT;
 782
 783         context = child->bts;
 784         if (!context)
 785                 context = alloc_bts_context(child);
 786         if (!context)
 787                 return -ENOMEM;
 788
 789         if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
 790                 if (!cfg.signal)
 791                         return -EINVAL;
 792
 793                 return -EOPNOTSUPP;
 794                 context->bts_ovfl_signal = cfg.signal;
 795         }
 796
 797         ds_release_bts(context->tracer);
 798         context->tracer = NULL;
 799
 800         if ((cfg.flags & PTRACE_BTS_O_ALLOC) && (cfg.size != context->size)) {
 801                 int err;
 802
 803                 free_bts_buffer(context);
 804                 if (!cfg.size)
 805                         return 0;
 806
 807                 err = alloc_bts_buffer(context, cfg.size);
 808                 if (err < 0)
 809                         return err;
 810         }
 811
 812         if (cfg.flags & PTRACE_BTS_O_TRACE)
 813                 flags |= BTS_USER;
 814
 815         if (cfg.flags & PTRACE_BTS_O_SCHED)
 816                 flags |= BTS_TIMESTAMPS;
 817
 818         context->tracer =
 819                 ds_request_bts_task(child, context->buffer, context->size,
 820                                     NULL, (size_t)-1, flags);
 821         if (unlikely(IS_ERR(context->tracer))) {
 822                 int error = PTR_ERR(context->tracer);
 823
 824                 free_bts_buffer(context);
 825                 context->tracer = NULL;
 826                 return error;
 827         }
 828
 829         return sizeof(cfg);
 830 }
 831
 832 static int ptrace_bts_status(struct task_struct *child,
 833                              long cfg_size,
 834                              struct ptrace_bts_config __user *ucfg)
 835 {
 836         struct bts_context *context;
 837         const struct bts_trace *trace;
 838         struct ptrace_bts_config cfg;
 839
 840         context = child->bts;
 841         if (!context)
 842                 return -ESRCH;
 843
 844         if (cfg_size < sizeof(cfg))
 845                 return -EIO;
 846
 847         trace = ds_read_bts(context->tracer);
 848         if (!trace)
 849                 return -ESRCH;
 850
 851         memset(&cfg, 0, sizeof(cfg));
 852         cfg.size        = trace->ds.end - trace->ds.begin;
 853         cfg.signal      = context->bts_ovfl_signal;
 854         cfg.bts_size    = sizeof(struct bts_struct);
 855
 856         if (cfg.signal)
 857                 cfg.flags |= PTRACE_BTS_O_SIGNAL;
 858
 859         if (trace->ds.flags & BTS_USER)
 860                 cfg.flags |= PTRACE_BTS_O_TRACE;
 861
 862         if (trace->ds.flags & BTS_TIMESTAMPS)
 863                 cfg.flags |= PTRACE_BTS_O_SCHED;
 864
 865         if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
 866                 return -EFAULT;
 867
 868         return sizeof(cfg);
 869 }
 870
 871 static int ptrace_bts_clear(struct task_struct *child)
 872 {
 873         struct bts_context *context;
 874         const struct bts_trace *trace;
 875
 876         context = child->bts;
 877         if (!context)
 878                 return -ESRCH;
 879
 880         trace = ds_read_bts(context->tracer);
 881         if (!trace)
 882                 return -ESRCH;
 883
 884         memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
 885
 886         return ds_reset_bts(context->tracer);
 887 }
 888
 889 static int ptrace_bts_size(struct task_struct *child)
 890 {
 891         struct bts_context *context;
 892         const struct bts_trace *trace;
 893
 894         context = child->bts;
 895         if (!context)
 896                 return -ESRCH;
 897
 898         trace = ds_read_bts(context->tracer);
 899         if (!trace)
 900                 return -ESRCH;
 901
 902         return (trace->ds.top - trace->ds.begin) / trace->ds.size;
 903 }
 904
 905 /*
 906  * Called from __ptrace_unlink() after the child has been moved back
 907  * to its original parent.
 908  */
 909 void ptrace_bts_untrace(struct task_struct *child)
 910 {
 911         if (unlikely(child->bts)) {
 912                 free_bts_context(child->bts);
 913                 child->bts = NULL;
 914         }
 915 }
 916 #endif /* CONFIG_X86_PTRACE_BTS */
 917
 918 /*
 919  * Called by kernel/ptrace.c when detaching..
 920  *
 921  * Make sure the single step bit is not set.
 922  */
 923 void ptrace_disable(struct task_struct *child)
 924 {
 925         user_disable_single_step(child);
 926 #ifdef TIF_SYSCALL_EMU
 927         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 928 #endif
 929 }
 930
 931 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
 932 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
 933 #endif
 934
 935 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 936 {
 937         int ret;
 938         unsigned long __user *datap = (unsigned long __user *)data;
 939
 940         switch (request) {
 941         /* read the word at location addr in the USER area. */
 942         case PTRACE_PEEKUSR: {
 943                 unsigned long tmp;
 944
 945                 ret = -EIO;
 946                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
 947                     addr >= sizeof(struct user))
 948                         break;
 949
 950                 tmp = 0;  /* Default return condition */
 951                 if (addr < sizeof(struct user_regs_struct))
 952                         tmp = getreg(child, addr);
 953                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 954                          addr <= offsetof(struct user, u_debugreg[7])) {
 955                         addr -= offsetof(struct user, u_debugreg[0]);
 956                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
 957                 }
 958                 ret = put_user(tmp, datap);
 959                 break;
 960         }
 961
 962         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 963                 ret = -EIO;
 964                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
 965                     addr >= sizeof(struct user))
 966                         break;
 967
 968                 if (addr < sizeof(struct user_regs_struct))
 969                         ret = putreg(child, addr, data);
 970                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
 971                          addr <= offsetof(struct user, u_debugreg[7])) {
 972                         addr -= offsetof(struct user, u_debugreg[0]);
 973                         ret = ptrace_set_debugreg(child,
 974                                                   addr / sizeof(data), data);
 975                 }
 976                 break;
 977
 978         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
 979                 return copy_regset_to_user(child,
 980                                            task_user_regset_view(current),
 981                                            REGSET_GENERAL,
 982                                            0, sizeof(struct user_regs_struct),
 983                                            datap);
 984
 985         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 986                 return copy_regset_from_user(child,
 987                                              task_user_regset_view(current),
 988                                              REGSET_GENERAL,
 989                                              0, sizeof(struct user_regs_struct),
 990                                              datap);
 991
 992         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
 993                 return copy_regset_to_user(child,
 994                                            task_user_regset_view(current),
 995                                            REGSET_FP,
 996                                            0, sizeof(struct user_i387_struct),
 997                                            datap);
 998
 999         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1000                 return copy_regset_from_user(child,
1001                                              task_user_regset_view(current),
1002                                              REGSET_FP,
1003                                              0, sizeof(struct user_i387_struct),
1004                                              datap);
1005
1006 #ifdef CONFIG_X86_32
1007         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1008                 return copy_regset_to_user(child, &user_x86_32_view,
1009                                            REGSET_XFP,
1010                                            0, sizeof(struct user_fxsr_struct),
1011                                            datap) ? -EIO : 0;
1012
1013         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1014                 return copy_regset_from_user(child, &user_x86_32_view,
1015                                              REGSET_XFP,
1016                                              0, sizeof(struct user_fxsr_struct),
1017                                              datap) ? -EIO : 0;
1018 #endif
1019
1020 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1021         case PTRACE_GET_THREAD_AREA:
1022                 if (addr < 0)
1023                         return -EIO;
1024                 ret = do_get_thread_area(child, addr,
1025                                          (struct user_desc __user *) data);
1026                 break;
1027
1028         case PTRACE_SET_THREAD_AREA:
1029                 if (addr < 0)
1030                         return -EIO;
1031                 ret = do_set_thread_area(child, addr,
1032                                          (struct user_desc __user *) data, 0);
1033                 break;
1034 #endif
1035
1036 #ifdef CONFIG_X86_64
1037                 /* normal 64bit interface to access TLS data.
1038                    Works just like arch_prctl, except that the arguments
1039                    are reversed. */
1040         case PTRACE_ARCH_PRCTL:
1041                 ret = do_arch_prctl(child, data, addr);
1042                 break;
1043 #endif
1044
1045         /*
1046          * These bits need more cooking - not enabled yet:
1047          */
1048 #ifdef CONFIG_X86_PTRACE_BTS
1049         case PTRACE_BTS_CONFIG:
1050                 ret = ptrace_bts_config
1051                         (child, data, (struct ptrace_bts_config __user *)addr);
1052                 break;
1053
1054         case PTRACE_BTS_STATUS:
1055                 ret = ptrace_bts_status
1056                         (child, data, (struct ptrace_bts_config __user *)addr);
1057                 break;
1058
1059         case PTRACE_BTS_SIZE:
1060                 ret = ptrace_bts_size(child);
1061                 break;
1062
1063         case PTRACE_BTS_GET:
1064                 ret = ptrace_bts_read_record
1065                         (child, data, (struct bts_struct __user *) addr);
1066                 break;
1067
1068         case PTRACE_BTS_CLEAR:
1069                 ret = ptrace_bts_clear(child);
1070                 break;
1071
1072         case PTRACE_BTS_DRAIN:
1073                 ret = ptrace_bts_drain
1074                         (child, data, (struct bts_struct __user *) addr);
1075                 break;
1076 #endif /* CONFIG_X86_PTRACE_BTS */
1077
1078         default:
1079                 ret = ptrace_request(child, request, addr, data);
1080                 break;
1081         }
1082
1083         return ret;
1084 }
1085
1086 #ifdef CONFIG_IA32_EMULATION
1087
1088 #include <linux/compat.h>
1089 #include <linux/syscalls.h>
1090 #include <asm/ia32.h>
1091 #include <asm/user32.h>
1092
1093 #define R32(l,q)                                                        \
1094         case offsetof(struct user32, regs.l):                           \
1095                 regs->q = value; break
1096
1097 #define SEG32(rs)                                                       \
1098         case offsetof(struct user32, regs.rs):                          \
1099                 return set_segment_reg(child,                           \
1100                                        offsetof(struct user_regs_struct, rs), \
1101                                        value);                          \
1102                 break
1103
1104 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
1105 {
1106         struct pt_regs *regs = task_pt_regs(child);
1107
1108         switch (regno) {
1109
1110         SEG32(cs);
1111         SEG32(ds);
1112         SEG32(es);
1113         SEG32(fs);
1114         SEG32(gs);
1115         SEG32(ss);
1116
1117         R32(ebx, bx);
1118         R32(ecx, cx);
1119         R32(edx, dx);
1120         R32(edi, di);
1121         R32(esi, si);
1122         R32(ebp, bp);
1123         R32(eax, ax);
1124         R32(eip, ip);
1125         R32(esp, sp);
1126
1127         case offsetof(struct user32, regs.orig_eax):
1128                 /*
1129                  * Sign-extend the value so that orig_eax = -1
1130                  * causes (long)orig_ax < 0 tests to fire correctly.
1131                  */
1132                 regs->orig_ax = (long) (s32) value;
1133                 break;
1134
1135         case offsetof(struct user32, regs.eflags):
1136                 return set_flags(child, value);
1137
1138         case offsetof(struct user32, u_debugreg[0]) ...
1139                 offsetof(struct user32, u_debugreg[7]):
1140                 regno -= offsetof(struct user32, u_debugreg[0]);
1141                 return ptrace_set_debugreg(child, regno / 4, value);
1142
1143         default:
1144                 if (regno > sizeof(struct user32) || (regno & 3))
1145                         return -EIO;
1146
1147                 /*
1148                  * Other dummy fields in the virtual user structure
1149                  * are ignored
1150                  */
1151                 break;
1152         }
1153         return 0;
1154 }
1155
1156 #undef R32
1157 #undef SEG32
1158
1159 #define R32(l,q)                                                        \
1160         case offsetof(struct user32, regs.l):                           \
1161                 *val = regs->q; break
1162
1163 #define SEG32(rs)                                                       \
1164         case offsetof(struct user32, regs.rs):                          \
1165                 *val = get_segment_reg(child,                           \
1166                                        offsetof(struct user_regs_struct, rs)); \
1167                 break
1168
1169 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1170 {
1171         struct pt_regs *regs = task_pt_regs(child);
1172
1173         switch (regno) {
1174
1175         SEG32(ds);
1176         SEG32(es);
1177         SEG32(fs);
1178         SEG32(gs);
1179
1180         R32(cs, cs);
1181         R32(ss, ss);
1182         R32(ebx, bx);
1183         R32(ecx, cx);
1184         R32(edx, dx);
1185         R32(edi, di);
1186         R32(esi, si);
1187         R32(ebp, bp);
1188         R32(eax, ax);
1189         R32(orig_eax, orig_ax);
1190         R32(eip, ip);
1191         R32(esp, sp);
1192
1193         case offsetof(struct user32, regs.eflags):
1194                 *val = get_flags(child);
1195                 break;
1196
1197         case offsetof(struct user32, u_debugreg[0]) ...
1198                 offsetof(struct user32, u_debugreg[7]):
1199                 regno -= offsetof(struct user32, u_debugreg[0]);
1200                 *val = ptrace_get_debugreg(child, regno / 4);
1201                 break;
1202
1203         default:
1204                 if (regno > sizeof(struct user32) || (regno & 3))
1205                         return -EIO;
1206
1207                 /*
1208                  * Other dummy fields in the virtual user structure
1209                  * are ignored
1210                  */
1211                 *val = 0;
1212                 break;
1213         }
1214         return 0;
1215 }
1216
1217 #undef R32
1218 #undef SEG32
1219
1220 static int genregs32_get(struct task_struct *target,
1221                          const struct user_regset *regset,
1222                          unsigned int pos, unsigned int count,
1223                          void *kbuf, void __user *ubuf)
1224 {
1225         if (kbuf) {
1226                 compat_ulong_t *k = kbuf;
1227                 while (count > 0) {
1228                         getreg32(target, pos, k++);
1229                         count -= sizeof(*k);
1230                         pos += sizeof(*k);
1231                 }
1232         } else {
1233                 compat_ulong_t __user *u = ubuf;
1234                 while (count > 0) {
1235                         compat_ulong_t word;
1236                         getreg32(target, pos, &word);
1237                         if (__put_user(word, u++))
1238                                 return -EFAULT;
1239                         count -= sizeof(*u);
1240                         pos += sizeof(*u);
1241                 }
1242         }
1243
1244         return 0;
1245 }
1246
1247 static int genregs32_set(struct task_struct *target,
1248                          const struct user_regset *regset,
1249                          unsigned int pos, unsigned int count,
1250                          const void *kbuf, const void __user *ubuf)
1251 {
1252         int ret = 0;
1253         if (kbuf) {
1254                 const compat_ulong_t *k = kbuf;
1255                 while (count > 0 && !ret) {
1256                         ret = putreg32(target, pos, *k++);
1257                         count -= sizeof(*k);
1258                         pos += sizeof(*k);
1259                 }
1260         } else {
1261                 const compat_ulong_t __user *u = ubuf;
1262                 while (count > 0 && !ret) {
1263                         compat_ulong_t word;
1264                         ret = __get_user(word, u++);
1265                         if (ret)
1266                                 break;
1267                         ret = putreg32(target, pos, word);
1268                         count -= sizeof(*u);
1269                         pos += sizeof(*u);
1270                 }
1271         }
1272         return ret;
1273 }
1274
1275 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1276                         compat_ulong_t caddr, compat_ulong_t cdata)
1277 {
1278         unsigned long addr = caddr;
1279         unsigned long data = cdata;
1280         void __user *datap = compat_ptr(data);
1281         int ret;
1282         __u32 val;
1283
1284         switch (request) {
1285         case PTRACE_PEEKUSR:
1286                 ret = getreg32(child, addr, &val);
1287                 if (ret == 0)
1288                         ret = put_user(val, (__u32 __user *)datap);
1289                 break;
1290
1291         case PTRACE_POKEUSR:
1292                 ret = putreg32(child, addr, data);
1293                 break;
1294
1295         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1296                 return copy_regset_to_user(child, &user_x86_32_view,
1297                                            REGSET_GENERAL,
1298                                            0, sizeof(struct user_regs_struct32),
1299                                            datap);
1300
1301         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1302                 return copy_regset_from_user(child, &user_x86_32_view,
1303                                              REGSET_GENERAL, 0,
1304                                              sizeof(struct user_regs_struct32),
1305                                              datap);
1306
1307         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1308                 return copy_regset_to_user(child, &user_x86_32_view,
1309                                            REGSET_FP, 0,
1310                                            sizeof(struct user_i387_ia32_struct),
1311                                            datap);
1312
1313         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1314                 return copy_regset_from_user(
1315                         child, &user_x86_32_view, REGSET_FP,
1316                         0, sizeof(struct user_i387_ia32_struct), datap);
1317
1318         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1319                 return copy_regset_to_user(child, &user_x86_32_view,
1320                                            REGSET_XFP, 0,
1321                                            sizeof(struct user32_fxsr_struct),
1322                                            datap);
1323
1324         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1325                 return copy_regset_from_user(child, &user_x86_32_view,
1326                                              REGSET_XFP, 0,
1327                                              sizeof(struct user32_fxsr_struct),
1328                                              datap);
1329
1330         case PTRACE_GET_THREAD_AREA:
1331         case PTRACE_SET_THREAD_AREA:
1332 #ifdef CONFIG_X86_PTRACE_BTS
1333         case PTRACE_BTS_CONFIG:
1334         case PTRACE_BTS_STATUS:
1335         case PTRACE_BTS_SIZE:
1336         case PTRACE_BTS_GET:
1337         case PTRACE_BTS_CLEAR:
1338         case PTRACE_BTS_DRAIN:
1339 #endif /* CONFIG_X86_PTRACE_BTS */
1340                 return arch_ptrace(child, request, addr, data);
1341
1342         default:
1343                 return compat_ptrace_request(child, request, addr, data);
1344         }
1345
1346         return ret;
1347 }
1348
1349 #endif  /* CONFIG_IA32_EMULATION */
1350
1351 #ifdef CONFIG_X86_64
1352
1353 static const struct user_regset x86_64_regsets[] = {
1354         [REGSET_GENERAL] = {
1355                 .core_note_type = NT_PRSTATUS,
1356                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1357                 .size = sizeof(long), .align = sizeof(long),
1358                 .get = genregs_get, .set = genregs_set
1359         },
1360         [REGSET_FP] = {
1361                 .core_note_type = NT_PRFPREG,
1362                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1363                 .size = sizeof(long), .align = sizeof(long),
1364                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1365         },
1366         [REGSET_IOPERM64] = {
1367                 .core_note_type = NT_386_IOPERM,
1368                 .n = IO_BITMAP_LONGS,
1369                 .size = sizeof(long), .align = sizeof(long),
1370                 .active = ioperm_active, .get = ioperm_get
1371         },
1372 };
1373
1374 static const struct user_regset_view user_x86_64_view = {
1375         .name = "x86_64", .e_machine = EM_X86_64,
1376         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1377 };
1378
1379 #else  /* CONFIG_X86_32 */
1380
1381 #define user_regs_struct32      user_regs_struct
1382 #define genregs32_get           genregs_get
1383 #define genregs32_set           genregs_set
1384
1385 #define user_i387_ia32_struct   user_i387_struct
1386 #define user32_fxsr_struct      user_fxsr_struct
1387
1388 #endif  /* CONFIG_X86_64 */
1389
1390 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1391 static const struct user_regset x86_32_regsets[] = {
1392         [REGSET_GENERAL] = {
1393                 .core_note_type = NT_PRSTATUS,
1394                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1395                 .size = sizeof(u32), .align = sizeof(u32),
1396                 .get = genregs32_get, .set = genregs32_set
1397         },
1398         [REGSET_FP] = {
1399                 .core_note_type = NT_PRFPREG,
1400                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1401                 .size = sizeof(u32), .align = sizeof(u32),
1402                 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1403         },
1404         [REGSET_XFP] = {
1405                 .core_note_type = NT_PRXFPREG,
1406                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1407                 .size = sizeof(u32), .align = sizeof(u32),
1408                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1409         },
1410         [REGSET_TLS] = {
1411                 .core_note_type = NT_386_TLS,
1412                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1413                 .size = sizeof(struct user_desc),
1414                 .align = sizeof(struct user_desc),
1415                 .active = regset_tls_active,
1416                 .get = regset_tls_get, .set = regset_tls_set
1417         },
1418         [REGSET_IOPERM32] = {
1419                 .core_note_type = NT_386_IOPERM,
1420                 .n = IO_BITMAP_BYTES / sizeof(u32),
1421                 .size = sizeof(u32), .align = sizeof(u32),
1422                 .active = ioperm_active, .get = ioperm_get
1423         },
1424 };
1425
1426 static const struct user_regset_view user_x86_32_view = {
1427         .name = "i386", .e_machine = EM_386,
1428         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1429 };
1430 #endif
1431
1432 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1433 {
1434 #ifdef CONFIG_IA32_EMULATION
1435         if (test_tsk_thread_flag(task, TIF_IA32))
1436 #endif
1437 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1438                 return &user_x86_32_view;
1439 #endif
1440 #ifdef CONFIG_X86_64
1441         return &user_x86_64_view;
1442 #endif
1443 }
1444
1445 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1446                                          int error_code, int si_code)
1447 {
1448         struct siginfo info;
1449
1450         tsk->thread.trap_no = 1;
1451         tsk->thread.error_code = error_code;
1452
1453         memset(&info, 0, sizeof(info));
1454         info.si_signo = SIGTRAP;
1455         info.si_code = si_code;
1456
1457         /* User-mode ip? */
1458         info.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL;
1459
1460         /* Send us the fake SIGTRAP */
1461         force_sig_info(SIGTRAP, &info, tsk);
1462 }
1463
1464
1465 #ifdef CONFIG_X86_32
1466 # define IS_IA32        1
1467 #elif defined CONFIG_IA32_EMULATION
1468 # define IS_IA32        is_compat_task()
1469 #else
1470 # define IS_IA32        0
1471 #endif
1472
1473 /*
1474  * We must return the syscall number to actually look up in the table.
1475  * This can be -1L to skip running any syscall at all.
1476  */
1477 asmregparm long syscall_trace_enter(struct pt_regs *regs)
1478 {
1479         long ret = 0;
1480
1481         /*
1482          * If we stepped into a sysenter/syscall insn, it trapped in
1483          * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1484          * If user-mode had set TF itself, then it's still clear from
1485          * do_debug() and we need to set it again to restore the user
1486          * state.  If we entered on the slow path, TF was already set.
1487          */
1488         if (test_thread_flag(TIF_SINGLESTEP))
1489                 regs->flags |= X86_EFLAGS_TF;
1490
1491         /* do the secure computing check first */
1492         secure_computing(regs->orig_ax);
1493
1494         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1495                 ret = -1L;
1496
1497         if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1498             tracehook_report_syscall_entry(regs))
1499                 ret = -1L;
1500
1501         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1502                 trace_sys_enter(regs, regs->orig_ax);
1503
1504         if (unlikely(current->audit_context)) {
1505                 if (IS_IA32)
1506                         audit_syscall_entry(AUDIT_ARCH_I386,
1507                                             regs->orig_ax,
1508                                             regs->bx, regs->cx,
1509                                             regs->dx, regs->si);
1510 #ifdef CONFIG_X86_64
1511                 else
1512                         audit_syscall_entry(AUDIT_ARCH_X86_64,
1513                                             regs->orig_ax,
1514                                             regs->di, regs->si,
1515                                             regs->dx, regs->r10);
1516 #endif
1517         }
1518
1519         return ret ?: regs->orig_ax;
1520 }
1521
1522 asmregparm void syscall_trace_leave(struct pt_regs *regs)
1523 {
1524         if (unlikely(current->audit_context))
1525                 audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
1526
1527         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1528                 trace_sys_exit(regs, regs->ax);
1529
1530         if (test_thread_flag(TIF_SYSCALL_TRACE))
1531                 tracehook_report_syscall_exit(regs, 0);
1532
1533         /*
1534          * If TIF_SYSCALL_EMU is set, we only get here because of
1535          * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1536          * We already reported this syscall instruction in
1537          * syscall_trace_enter(), so don't do any more now.
1538          */
1539         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1540                 return;
1541
1542         /*
1543          * If we are single-stepping, synthesize a trap to follow the
1544          * system call instruction.
1545          */
1546         if (test_thread_flag(TIF_SINGLESTEP) &&
1547             tracehook_consider_fatal_signal(current, SIGTRAP))
1548                 send_sigtrap(current, regs, 0, TRAP_BRKPT);
1549 }