SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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 #include <linux/perf_event.h>
  26 #include <linux/hw_breakpoint.h>
  27
  28 #include <asm/uaccess.h>
  29 #include <asm/pgtable.h>
  30 #include <asm/system.h>
  31 #include <asm/processor.h>
  32 #include <asm/i387.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/ds.h>
  39 #include <asm/hw_breakpoint.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 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 172 {
 173         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
 174         return &regs->bx + (regno >> 2);
 175 }
 176
 177 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 178 {
 179         /*
 180          * Returning the value truncates it to 16 bits.
 181          */
 182         unsigned int retval;
 183         if (offset != offsetof(struct user_regs_struct, gs))
 184                 retval = *pt_regs_access(task_pt_regs(task), offset);
 185         else {
 186                 if (task == current)
 187                         retval = get_user_gs(task_pt_regs(task));
 188                 else
 189                         retval = task_user_gs(task);
 190         }
 191         return retval;
 192 }
 193
 194 static int set_segment_reg(struct task_struct *task,
 195                            unsigned long offset, u16 value)
 196 {
 197         /*
 198          * The value argument was already truncated to 16 bits.
 199          */
 200         if (invalid_selector(value))
 201                 return -EIO;
 202
 203         /*
 204          * For %cs and %ss we cannot permit a null selector.
 205          * We can permit a bogus selector as long as it has USER_RPL.
 206          * Null selectors are fine for other segment registers, but
 207          * we will never get back to user mode with invalid %cs or %ss
 208          * and will take the trap in iret instead.  Much code relies
 209          * on user_mode() to distinguish a user trap frame (which can
 210          * safely use invalid selectors) from a kernel trap frame.
 211          */
 212         switch (offset) {
 213         case offsetof(struct user_regs_struct, cs):
 214         case offsetof(struct user_regs_struct, ss):
 215                 if (unlikely(value == 0))
 216                         return -EIO;
 217
 218         default:
 219                 *pt_regs_access(task_pt_regs(task), offset) = value;
 220                 break;
 221
 222         case offsetof(struct user_regs_struct, gs):
 223                 if (task == current)
 224                         set_user_gs(task_pt_regs(task), value);
 225                 else
 226                         task_user_gs(task) = value;
 227         }
 228
 229         return 0;
 230 }
 231
 232 #else  /* CONFIG_X86_64 */
 233
 234 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
 235
 236 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 237 {
 238         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 239         return &regs->r15 + (offset / sizeof(regs->r15));
 240 }
 241
 242 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 243 {
 244         /*
 245          * Returning the value truncates it to 16 bits.
 246          */
 247         unsigned int seg;
 248
 249         switch (offset) {
 250         case offsetof(struct user_regs_struct, fs):
 251                 if (task == current) {
 252                         /* Older gas can't assemble movq %?s,%r?? */
 253                         asm("movl %%fs,%0" : "=r" (seg));
 254                         return seg;
 255                 }
 256                 return task->thread.fsindex;
 257         case offsetof(struct user_regs_struct, gs):
 258                 if (task == current) {
 259                         asm("movl %%gs,%0" : "=r" (seg));
 260                         return seg;
 261                 }
 262                 return task->thread.gsindex;
 263         case offsetof(struct user_regs_struct, ds):
 264                 if (task == current) {
 265                         asm("movl %%ds,%0" : "=r" (seg));
 266                         return seg;
 267                 }
 268                 return task->thread.ds;
 269         case offsetof(struct user_regs_struct, es):
 270                 if (task == current) {
 271                         asm("movl %%es,%0" : "=r" (seg));
 272                         return seg;
 273                 }
 274                 return task->thread.es;
 275
 276         case offsetof(struct user_regs_struct, cs):
 277         case offsetof(struct user_regs_struct, ss):
 278                 break;
 279         }
 280         return *pt_regs_access(task_pt_regs(task), offset);
 281 }
 282
 283 static int set_segment_reg(struct task_struct *task,
 284                            unsigned long offset, u16 value)
 285 {
 286         /*
 287          * The value argument was already truncated to 16 bits.
 288          */
 289         if (invalid_selector(value))
 290                 return -EIO;
 291
 292         switch (offset) {
 293         case offsetof(struct user_regs_struct,fs):
 294                 /*
 295                  * If this is setting fs as for normal 64-bit use but
 296                  * setting fs_base has implicitly changed it, leave it.
 297                  */
 298                 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
 299                      task->thread.fs != 0) ||
 300                     (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
 301                      task->thread.fs == 0))
 302                         break;
 303                 task->thread.fsindex = value;
 304                 if (task == current)
 305                         loadsegment(fs, task->thread.fsindex);
 306                 break;
 307         case offsetof(struct user_regs_struct,gs):
 308                 /*
 309                  * If this is setting gs as for normal 64-bit use but
 310                  * setting gs_base has implicitly changed it, leave it.
 311                  */
 312                 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
 313                      task->thread.gs != 0) ||
 314                     (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
 315                      task->thread.gs == 0))
 316                         break;
 317                 task->thread.gsindex = value;
 318                 if (task == current)
 319                         load_gs_index(task->thread.gsindex);
 320                 break;
 321         case offsetof(struct user_regs_struct,ds):
 322                 task->thread.ds = value;
 323                 if (task == current)
 324                         loadsegment(ds, task->thread.ds);
 325                 break;
 326         case offsetof(struct user_regs_struct,es):
 327                 task->thread.es = value;
 328                 if (task == current)
 329                         loadsegment(es, task->thread.es);
 330                 break;
 331
 332                 /*
 333                  * Can't actually change these in 64-bit mode.
 334                  */
 335         case offsetof(struct user_regs_struct,cs):
 336                 if (unlikely(value == 0))
 337                         return -EIO;
 338 #ifdef CONFIG_IA32_EMULATION
 339                 if (test_tsk_thread_flag(task, TIF_IA32))
 340                         task_pt_regs(task)->cs = value;
 341 #endif
 342                 break;
 343         case offsetof(struct user_regs_struct,ss):
 344                 if (unlikely(value == 0))
 345                         return -EIO;
 346 #ifdef CONFIG_IA32_EMULATION
 347                 if (test_tsk_thread_flag(task, TIF_IA32))
 348                         task_pt_regs(task)->ss = value;
 349 #endif
 350                 break;
 351         }
 352
 353         return 0;
 354 }
 355
 356 #endif  /* CONFIG_X86_32 */
 357
 358 static unsigned long get_flags(struct task_struct *task)
 359 {
 360         unsigned long retval = task_pt_regs(task)->flags;
 361
 362         /*
 363          * If the debugger set TF, hide it from the readout.
 364          */
 365         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 366                 retval &= ~X86_EFLAGS_TF;
 367
 368         return retval;
 369 }
 370
 371 static int set_flags(struct task_struct *task, unsigned long value)
 372 {
 373         struct pt_regs *regs = task_pt_regs(task);
 374
 375         /*
 376          * If the user value contains TF, mark that
 377          * it was not "us" (the debugger) that set it.
 378          * If not, make sure it stays set if we had.
 379          */
 380         if (value & X86_EFLAGS_TF)
 381                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
 382         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
 383                 value |= X86_EFLAGS_TF;
 384
 385         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
 386
 387         return 0;
 388 }
 389
 390 static int putreg(struct task_struct *child,
 391                   unsigned long offset, unsigned long value)
 392 {
 393         switch (offset) {
 394         case offsetof(struct user_regs_struct, cs):
 395         case offsetof(struct user_regs_struct, ds):
 396         case offsetof(struct user_regs_struct, es):
 397         case offsetof(struct user_regs_struct, fs):
 398         case offsetof(struct user_regs_struct, gs):
 399         case offsetof(struct user_regs_struct, ss):
 400                 return set_segment_reg(child, offset, value);
 401
 402         case offsetof(struct user_regs_struct, flags):
 403                 return set_flags(child, value);
 404
 405 #ifdef CONFIG_X86_64
 406         case offsetof(struct user_regs_struct,fs_base):
 407                 if (value >= TASK_SIZE_OF(child))
 408                         return -EIO;
 409                 /*
 410                  * When changing the segment base, use do_arch_prctl
 411                  * to set either thread.fs or thread.fsindex and the
 412                  * corresponding GDT slot.
 413                  */
 414                 if (child->thread.fs != value)
 415                         return do_arch_prctl(child, ARCH_SET_FS, value);
 416                 return 0;
 417         case offsetof(struct user_regs_struct,gs_base):
 418                 /*
 419                  * Exactly the same here as the %fs handling above.
 420                  */
 421                 if (value >= TASK_SIZE_OF(child))
 422                         return -EIO;
 423                 if (child->thread.gs != value)
 424                         return do_arch_prctl(child, ARCH_SET_GS, value);
 425                 return 0;
 426 #endif
 427         }
 428
 429         *pt_regs_access(task_pt_regs(child), offset) = value;
 430         return 0;
 431 }
 432
 433 static unsigned long getreg(struct task_struct *task, unsigned long offset)
 434 {
 435         switch (offset) {
 436         case offsetof(struct user_regs_struct, cs):
 437         case offsetof(struct user_regs_struct, ds):
 438         case offsetof(struct user_regs_struct, es):
 439         case offsetof(struct user_regs_struct, fs):
 440         case offsetof(struct user_regs_struct, gs):
 441         case offsetof(struct user_regs_struct, ss):
 442                 return get_segment_reg(task, offset);
 443
 444         case offsetof(struct user_regs_struct, flags):
 445                 return get_flags(task);
 446
 447 #ifdef CONFIG_X86_64
 448         case offsetof(struct user_regs_struct, fs_base): {
 449                 /*
 450                  * do_arch_prctl may have used a GDT slot instead of
 451                  * the MSR.  To userland, it appears the same either
 452                  * way, except the %fs segment selector might not be 0.
 453                  */
 454                 unsigned int seg = task->thread.fsindex;
 455                 if (task->thread.fs != 0)
 456                         return task->thread.fs;
 457                 if (task == current)
 458                         asm("movl %%fs,%0" : "=r" (seg));
 459                 if (seg != FS_TLS_SEL)
 460                         return 0;
 461                 return get_desc_base(&task->thread.tls_array[FS_TLS]);
 462         }
 463         case offsetof(struct user_regs_struct, gs_base): {
 464                 /*
 465                  * Exactly the same here as the %fs handling above.
 466                  */
 467                 unsigned int seg = task->thread.gsindex;
 468                 if (task->thread.gs != 0)
 469                         return task->thread.gs;
 470                 if (task == current)
 471                         asm("movl %%gs,%0" : "=r" (seg));
 472                 if (seg != GS_TLS_SEL)
 473                         return 0;
 474                 return get_desc_base(&task->thread.tls_array[GS_TLS]);
 475         }
 476 #endif
 477         }
 478
 479         return *pt_regs_access(task_pt_regs(task), offset);
 480 }
 481
 482 static int genregs_get(struct task_struct *target,
 483                        const struct user_regset *regset,
 484                        unsigned int pos, unsigned int count,
 485                        void *kbuf, void __user *ubuf)
 486 {
 487         if (kbuf) {
 488                 unsigned long *k = kbuf;
 489                 while (count >= sizeof(*k)) {
 490                         *k++ = getreg(target, pos);
 491                         count -= sizeof(*k);
 492                         pos += sizeof(*k);
 493                 }
 494         } else {
 495                 unsigned long __user *u = ubuf;
 496                 while (count >= sizeof(*u)) {
 497                         if (__put_user(getreg(target, pos), u++))
 498                                 return -EFAULT;
 499                         count -= sizeof(*u);
 500                         pos += sizeof(*u);
 501                 }
 502         }
 503
 504         return 0;
 505 }
 506
 507 static int genregs_set(struct task_struct *target,
 508                        const struct user_regset *regset,
 509                        unsigned int pos, unsigned int count,
 510                        const void *kbuf, const void __user *ubuf)
 511 {
 512         int ret = 0;
 513         if (kbuf) {
 514                 const unsigned long *k = kbuf;
 515                 while (count >= sizeof(*k) && !ret) {
 516                         ret = putreg(target, pos, *k++);
 517                         count -= sizeof(*k);
 518                         pos += sizeof(*k);
 519                 }
 520         } else {
 521                 const unsigned long  __user *u = ubuf;
 522                 while (count >= sizeof(*u) && !ret) {
 523                         unsigned long word;
 524                         ret = __get_user(word, u++);
 525                         if (ret)
 526                                 break;
 527                         ret = putreg(target, pos, word);
 528                         count -= sizeof(*u);
 529                         pos += sizeof(*u);
 530                 }
 531         }
 532         return ret;
 533 }
 534
 535 static void ptrace_triggered(struct perf_event *bp, int nmi,
 536                              struct perf_sample_data *data,
 537                              struct pt_regs *regs)
 538 {
 539         int i;
 540         struct thread_struct *thread = &(current->thread);
 541
 542         /*
 543          * Store in the virtual DR6 register the fact that the breakpoint
 544          * was hit so the thread's debugger will see it.
 545          */
 546         for (i = 0; i < HBP_NUM; i++) {
 547                 if (thread->ptrace_bps[i] == bp)
 548                         break;
 549         }
 550
 551         thread->debugreg6 |= (DR_TRAP0 << i);
 552 }
 553
 554 /*
 555  * Walk through every ptrace breakpoints for this thread and
 556  * build the dr7 value on top of their attributes.
 557  *
 558  */
 559 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
 560 {
 561         int i;
 562         int dr7 = 0;
 563         struct arch_hw_breakpoint *info;
 564
 565         for (i = 0; i < HBP_NUM; i++) {
 566                 if (bp[i] && !bp[i]->attr.disabled) {
 567                         info = counter_arch_bp(bp[i]);
 568                         dr7 |= encode_dr7(i, info->len, info->type);
 569                 }
 570         }
 571
 572         return dr7;
 573 }
 574
 575 static int
 576 ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
 577                          struct task_struct *tsk, int disabled)
 578 {
 579         int err;
 580         int gen_len, gen_type;
 581         struct perf_event_attr attr;
 582
 583         /*
 584          * We should have at least an inactive breakpoint at this
 585          * slot. It means the user is writing dr7 without having
 586          * written the address register first
 587          */
 588         if (!bp)
 589                 return -EINVAL;
 590
 591         err = arch_bp_generic_fields(len, type, &gen_len, &gen_type);
 592         if (err)
 593                 return err;
 594
 595         attr = bp->attr;
 596         attr.bp_len = gen_len;
 597         attr.bp_type = gen_type;
 598         attr.disabled = disabled;
 599
 600         return modify_user_hw_breakpoint(bp, &attr);
 601 }
 602
 603 /*
 604  * Handle ptrace writes to debug register 7.
 605  */
 606 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
 607 {
 608         struct thread_struct *thread = &(tsk->thread);
 609         unsigned long old_dr7;
 610         int i, orig_ret = 0, rc = 0;
 611         int enabled, second_pass = 0;
 612         unsigned len, type;
 613         struct perf_event *bp;
 614
 615         data &= ~DR_CONTROL_RESERVED;
 616         old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
 617 restore:
 618         /*
 619          * Loop through all the hardware breakpoints, making the
 620          * appropriate changes to each.
 621          */
 622         for (i = 0; i < HBP_NUM; i++) {
 623                 enabled = decode_dr7(data, i, &len, &type);
 624                 bp = thread->ptrace_bps[i];
 625
 626                 if (!enabled) {
 627                         if (bp) {
 628                                 /*
 629                                  * Don't unregister the breakpoints right-away,
 630                                  * unless all register_user_hw_breakpoint()
 631                                  * requests have succeeded. This prevents
 632                                  * any window of opportunity for debug
 633                                  * register grabbing by other users.
 634                                  */
 635                                 if (!second_pass)
 636                                         continue;
 637
 638                                 rc = ptrace_modify_breakpoint(bp, len, type,
 639                                                               tsk, 1);
 640                                 if (rc)
 641                                         break;
 642                         }
 643                         continue;
 644                 }
 645
 646                 rc = ptrace_modify_breakpoint(bp, len, type, tsk, 0);
 647                 if (rc)
 648                         break;
 649         }
 650         /*
 651          * Make a second pass to free the remaining unused breakpoints
 652          * or to restore the original breakpoints if an error occurred.
 653          */
 654         if (!second_pass) {
 655                 second_pass = 1;
 656                 if (rc < 0) {
 657                         orig_ret = rc;
 658                         data = old_dr7;
 659                 }
 660                 goto restore;
 661         }
 662         return ((orig_ret < 0) ? orig_ret : rc);
 663 }
 664
 665 /*
 666  * Handle PTRACE_PEEKUSR calls for the debug register area.
 667  */
 668 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
 669 {
 670         struct thread_struct *thread = &(tsk->thread);
 671         unsigned long val = 0;
 672
 673         if (n < HBP_NUM) {
 674                 struct perf_event *bp;
 675                 bp = thread->ptrace_bps[n];
 676                 if (!bp)
 677                         return 0;
 678                 val = bp->hw.info.address;
 679         } else if (n == 6) {
 680                 val = thread->debugreg6;
 681          } else if (n == 7) {
 682                 val = thread->ptrace_dr7;
 683         }
 684         return val;
 685 }
 686
 687 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 688                                       unsigned long addr)
 689 {
 690         struct perf_event *bp;
 691         struct thread_struct *t = &tsk->thread;
 692         struct perf_event_attr attr;
 693
 694         if (!t->ptrace_bps[nr]) {
 695                 hw_breakpoint_init(&attr);
 696                 /*
 697                  * Put stub len and type to register (reserve) an inactive but
 698                  * correct bp
 699                  */
 700                 attr.bp_addr = addr;
 701                 attr.bp_len = HW_BREAKPOINT_LEN_1;
 702                 attr.bp_type = HW_BREAKPOINT_W;
 703                 attr.disabled = 1;
 704
 705                 bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk);
 706
 707                 /*
 708                  * CHECKME: the previous code returned -EIO if the addr wasn't
 709                  * a valid task virtual addr. The new one will return -EINVAL in
 710                  *  this case.
 711                  * -EINVAL may be what we want for in-kernel breakpoints users,
 712                  * but -EIO looks better for ptrace, since we refuse a register
 713                  * writing for the user. And anyway this is the previous
 714                  * behaviour.
 715                  */
 716                 if (IS_ERR(bp))
 717                         return PTR_ERR(bp);
 718
 719                 t->ptrace_bps[nr] = bp;
 720         } else {
 721                 int err;
 722
 723                 bp = t->ptrace_bps[nr];
 724
 725                 attr = bp->attr;
 726                 attr.bp_addr = addr;
 727                 err = modify_user_hw_breakpoint(bp, &attr);
 728                 if (err)
 729                         return err;
 730         }
 731
 732
 733         return 0;
 734 }
 735
 736 /*
 737  * Handle PTRACE_POKEUSR calls for the debug register area.
 738  */
 739 int ptrace_set_debugreg(struct task_struct *tsk, int n, unsigned long val)
 740 {
 741         struct thread_struct *thread = &(tsk->thread);
 742         int rc = 0;
 743
 744         /* There are no DR4 or DR5 registers */
 745         if (n == 4 || n == 5)
 746                 return -EIO;
 747
 748         if (n == 6) {
 749                 thread->debugreg6 = val;
 750                 goto ret_path;
 751         }
 752         if (n < HBP_NUM) {
 753                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
 754                 if (rc)
 755                         return rc;
 756         }
 757         /* All that's left is DR7 */
 758         if (n == 7) {
 759                 rc = ptrace_write_dr7(tsk, val);
 760                 if (!rc)
 761                         thread->ptrace_dr7 = val;
 762         }
 763
 764 ret_path:
 765         return rc;
 766 }
 767
 768 /*
 769  * These access the current or another (stopped) task's io permission
 770  * bitmap for debugging or core dump.
 771  */
 772 static int ioperm_active(struct task_struct *target,
 773                          const struct user_regset *regset)
 774 {
 775         return target->thread.io_bitmap_max / regset->size;
 776 }
 777
 778 static int ioperm_get(struct task_struct *target,
 779                       const struct user_regset *regset,
 780                       unsigned int pos, unsigned int count,
 781                       void *kbuf, void __user *ubuf)
 782 {
 783         if (!target->thread.io_bitmap_ptr)
 784                 return -ENXIO;
 785
 786         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 787                                    target->thread.io_bitmap_ptr,
 788                                    0, IO_BITMAP_BYTES);
 789 }
 790
 791 #ifdef CONFIG_X86_PTRACE_BTS
 792 /*
 793  * A branch trace store context.
 794  *
 795  * Contexts may only be installed by ptrace_bts_config() and only for
 796  * ptraced tasks.
 797  *
 798  * Contexts are destroyed when the tracee is detached from the tracer.
 799  * The actual destruction work requires interrupts enabled, so the
 800  * work is deferred and will be scheduled during __ptrace_unlink().
 801  *
 802  * Contexts hold an additional task_struct reference on the traced
 803  * task, as well as a reference on the tracer's mm.
 804  *
 805  * Ptrace already holds a task_struct for the duration of ptrace operations,
 806  * but since destruction is deferred, it may be executed after both
 807  * tracer and tracee exited.
 808  */
 809 struct bts_context {
 810         /* The branch trace handle. */
 811         struct bts_tracer       *tracer;
 812
 813         /* The buffer used to store the branch trace and its size. */
 814         void                    *buffer;
 815         unsigned int            size;
 816
 817         /* The mm that paid for the above buffer. */
 818         struct mm_struct        *mm;
 819
 820         /* The task this context belongs to. */
 821         struct task_struct      *task;
 822
 823         /* The signal to send on a bts buffer overflow. */
 824         unsigned int            bts_ovfl_signal;
 825
 826         /* The work struct to destroy a context. */
 827         struct work_struct      work;
 828 };
 829
 830 static int alloc_bts_buffer(struct bts_context *context, unsigned int size)
 831 {
 832         void *buffer = NULL;
 833         int err = -ENOMEM;
 834
 835         err = account_locked_memory(current->mm, current->signal->rlim, size);
 836         if (err < 0)
 837                 return err;
 838
 839         buffer = kzalloc(size, GFP_KERNEL);
 840         if (!buffer)
 841                 goto out_refund;
 842
 843         context->buffer = buffer;
 844         context->size = size;
 845         context->mm = get_task_mm(current);
 846
 847         return 0;
 848
 849  out_refund:
 850         refund_locked_memory(current->mm, size);
 851         return err;
 852 }
 853
 854 static inline void free_bts_buffer(struct bts_context *context)
 855 {
 856         if (!context->buffer)
 857                 return;
 858
 859         kfree(context->buffer);
 860         context->buffer = NULL;
 861
 862         refund_locked_memory(context->mm, context->size);
 863         context->size = 0;
 864
 865         mmput(context->mm);
 866         context->mm = NULL;
 867 }
 868
 869 static void free_bts_context_work(struct work_struct *w)
 870 {
 871         struct bts_context *context;
 872
 873         context = container_of(w, struct bts_context, work);
 874
 875         ds_release_bts(context->tracer);
 876         put_task_struct(context->task);
 877         free_bts_buffer(context);
 878         kfree(context);
 879 }
 880
 881 static inline void free_bts_context(struct bts_context *context)
 882 {
 883         INIT_WORK(&context->work, free_bts_context_work);
 884         schedule_work(&context->work);
 885 }
 886
 887 static inline struct bts_context *alloc_bts_context(struct task_struct *task)
 888 {
 889         struct bts_context *context = kzalloc(sizeof(*context), GFP_KERNEL);
 890         if (context) {
 891                 context->task = task;
 892                 task->bts = context;
 893
 894                 get_task_struct(task);
 895         }
 896
 897         return context;
 898 }
 899
 900 static int ptrace_bts_read_record(struct task_struct *child, size_t index,
 901                                   struct bts_struct __user *out)
 902 {
 903         struct bts_context *context;
 904         const struct bts_trace *trace;
 905         struct bts_struct bts;
 906         const unsigned char *at;
 907         int error;
 908
 909         context = child->bts;
 910         if (!context)
 911                 return -ESRCH;
 912
 913         trace = ds_read_bts(context->tracer);
 914         if (!trace)
 915                 return -ESRCH;
 916
 917         at = trace->ds.top - ((index + 1) * trace->ds.size);
 918         if ((void *)at < trace->ds.begin)
 919                 at += (trace->ds.n * trace->ds.size);
 920
 921         if (!trace->read)
 922                 return -EOPNOTSUPP;
 923
 924         error = trace->read(context->tracer, at, &bts);
 925         if (error < 0)
 926                 return error;
 927
 928         if (copy_to_user(out, &bts, sizeof(bts)))
 929                 return -EFAULT;
 930
 931         return sizeof(bts);
 932 }
 933
 934 static int ptrace_bts_drain(struct task_struct *child,
 935                             long size,
 936                             struct bts_struct __user *out)
 937 {
 938         struct bts_context *context;
 939         const struct bts_trace *trace;
 940         const unsigned char *at;
 941         int error, drained = 0;
 942
 943         context = child->bts;
 944         if (!context)
 945                 return -ESRCH;
 946
 947         trace = ds_read_bts(context->tracer);
 948         if (!trace)
 949                 return -ESRCH;
 950
 951         if (!trace->read)
 952                 return -EOPNOTSUPP;
 953
 954         if (size < (trace->ds.top - trace->ds.begin))
 955                 return -EIO;
 956
 957         for (at = trace->ds.begin; (void *)at < trace->ds.top;
 958              out++, drained++, at += trace->ds.size) {
 959                 struct bts_struct bts;
 960
 961                 error = trace->read(context->tracer, at, &bts);
 962                 if (error < 0)
 963                         return error;
 964
 965                 if (copy_to_user(out, &bts, sizeof(bts)))
 966                         return -EFAULT;
 967         }
 968
 969         memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
 970
 971         error = ds_reset_bts(context->tracer);
 972         if (error < 0)
 973                 return error;
 974
 975         return drained;
 976 }
 977
 978 static int ptrace_bts_config(struct task_struct *child,
 979                              long cfg_size,
 980                              const struct ptrace_bts_config __user *ucfg)
 981 {
 982         struct bts_context *context;
 983         struct ptrace_bts_config cfg;
 984         unsigned int flags = 0;
 985
 986         if (cfg_size < sizeof(cfg))
 987                 return -EIO;
 988
 989         if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
 990                 return -EFAULT;
 991
 992         context = child->bts;
 993         if (!context)
 994                 context = alloc_bts_context(child);
 995         if (!context)
 996                 return -ENOMEM;
 997
 998         if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
 999                 if (!cfg.signal)
1000                         return -EINVAL;
1001
1002                 return -EOPNOTSUPP;
1003                 context->bts_ovfl_signal = cfg.signal;
1004         }
1005
1006         ds_release_bts(context->tracer);
1007         context->tracer = NULL;
1008
1009         if ((cfg.flags & PTRACE_BTS_O_ALLOC) && (cfg.size != context->size)) {
1010                 int err;
1011
1012                 free_bts_buffer(context);
1013                 if (!cfg.size)
1014                         return 0;
1015
1016                 err = alloc_bts_buffer(context, cfg.size);
1017                 if (err < 0)
1018                         return err;
1019         }
1020
1021         if (cfg.flags & PTRACE_BTS_O_TRACE)
1022                 flags |= BTS_USER;
1023
1024         if (cfg.flags & PTRACE_BTS_O_SCHED)
1025                 flags |= BTS_TIMESTAMPS;
1026
1027         context->tracer =
1028                 ds_request_bts_task(child, context->buffer, context->size,
1029                                     NULL, (size_t)-1, flags);
1030         if (unlikely(IS_ERR(context->tracer))) {
1031                 int error = PTR_ERR(context->tracer);
1032
1033                 free_bts_buffer(context);
1034                 context->tracer = NULL;
1035                 return error;
1036         }
1037
1038         return sizeof(cfg);
1039 }
1040
1041 static int ptrace_bts_status(struct task_struct *child,
1042                              long cfg_size,
1043                              struct ptrace_bts_config __user *ucfg)
1044 {
1045         struct bts_context *context;
1046         const struct bts_trace *trace;
1047         struct ptrace_bts_config cfg;
1048
1049         context = child->bts;
1050         if (!context)
1051                 return -ESRCH;
1052
1053         if (cfg_size < sizeof(cfg))
1054                 return -EIO;
1055
1056         trace = ds_read_bts(context->tracer);
1057         if (!trace)
1058                 return -ESRCH;
1059
1060         memset(&cfg, 0, sizeof(cfg));
1061         cfg.size        = trace->ds.end - trace->ds.begin;
1062         cfg.signal      = context->bts_ovfl_signal;
1063         cfg.bts_size    = sizeof(struct bts_struct);
1064
1065         if (cfg.signal)
1066                 cfg.flags |= PTRACE_BTS_O_SIGNAL;
1067
1068         if (trace->ds.flags & BTS_USER)
1069                 cfg.flags |= PTRACE_BTS_O_TRACE;
1070
1071         if (trace->ds.flags & BTS_TIMESTAMPS)
1072                 cfg.flags |= PTRACE_BTS_O_SCHED;
1073
1074         if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
1075                 return -EFAULT;
1076
1077         return sizeof(cfg);
1078 }
1079
1080 static int ptrace_bts_clear(struct task_struct *child)
1081 {
1082         struct bts_context *context;
1083         const struct bts_trace *trace;
1084
1085         context = child->bts;
1086         if (!context)
1087                 return -ESRCH;
1088
1089         trace = ds_read_bts(context->tracer);
1090         if (!trace)
1091                 return -ESRCH;
1092
1093         memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
1094
1095         return ds_reset_bts(context->tracer);
1096 }
1097
1098 static int ptrace_bts_size(struct task_struct *child)
1099 {
1100         struct bts_context *context;
1101         const struct bts_trace *trace;
1102
1103         context = child->bts;
1104         if (!context)
1105                 return -ESRCH;
1106
1107         trace = ds_read_bts(context->tracer);
1108         if (!trace)
1109                 return -ESRCH;
1110
1111         return (trace->ds.top - trace->ds.begin) / trace->ds.size;
1112 }
1113
1114 /*
1115  * Called from __ptrace_unlink() after the child has been moved back
1116  * to its original parent.
1117  */
1118 void ptrace_bts_untrace(struct task_struct *child)
1119 {
1120         if (unlikely(child->bts)) {
1121                 free_bts_context(child->bts);
1122                 child->bts = NULL;
1123         }
1124 }
1125 #endif /* CONFIG_X86_PTRACE_BTS */
1126
1127 /*
1128  * Called by kernel/ptrace.c when detaching..
1129  *
1130  * Make sure the single step bit is not set.
1131  */
1132 void ptrace_disable(struct task_struct *child)
1133 {
1134         user_disable_single_step(child);
1135 #ifdef TIF_SYSCALL_EMU
1136         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
1137 #endif
1138 }
1139
1140 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1141 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
1142 #endif
1143
1144 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
1145 {
1146         int ret;
1147         unsigned long __user *datap = (unsigned long __user *)data;
1148
1149         switch (request) {
1150         /* read the word at location addr in the USER area. */
1151         case PTRACE_PEEKUSR: {
1152                 unsigned long tmp;
1153
1154                 ret = -EIO;
1155                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
1156                     addr >= sizeof(struct user))
1157                         break;
1158
1159                 tmp = 0;  /* Default return condition */
1160                 if (addr < sizeof(struct user_regs_struct))
1161                         tmp = getreg(child, addr);
1162                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1163                          addr <= offsetof(struct user, u_debugreg[7])) {
1164                         addr -= offsetof(struct user, u_debugreg[0]);
1165                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1166                 }
1167                 ret = put_user(tmp, datap);
1168                 break;
1169         }
1170
1171         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
1172                 ret = -EIO;
1173                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
1174                     addr >= sizeof(struct user))
1175                         break;
1176
1177                 if (addr < sizeof(struct user_regs_struct))
1178                         ret = putreg(child, addr, data);
1179                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1180                          addr <= offsetof(struct user, u_debugreg[7])) {
1181                         addr -= offsetof(struct user, u_debugreg[0]);
1182                         ret = ptrace_set_debugreg(child,
1183                                                   addr / sizeof(data), data);
1184                 }
1185                 break;
1186
1187         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1188                 return copy_regset_to_user(child,
1189                                            task_user_regset_view(current),
1190                                            REGSET_GENERAL,
1191                                            0, sizeof(struct user_regs_struct),
1192                                            datap);
1193
1194         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1195                 return copy_regset_from_user(child,
1196                                              task_user_regset_view(current),
1197                                              REGSET_GENERAL,
1198                                              0, sizeof(struct user_regs_struct),
1199                                              datap);
1200
1201         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1202                 return copy_regset_to_user(child,
1203                                            task_user_regset_view(current),
1204                                            REGSET_FP,
1205                                            0, sizeof(struct user_i387_struct),
1206                                            datap);
1207
1208         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1209                 return copy_regset_from_user(child,
1210                                              task_user_regset_view(current),
1211                                              REGSET_FP,
1212                                              0, sizeof(struct user_i387_struct),
1213                                              datap);
1214
1215 #ifdef CONFIG_X86_32
1216         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1217                 return copy_regset_to_user(child, &user_x86_32_view,
1218                                            REGSET_XFP,
1219                                            0, sizeof(struct user_fxsr_struct),
1220                                            datap) ? -EIO : 0;
1221
1222         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1223                 return copy_regset_from_user(child, &user_x86_32_view,
1224                                              REGSET_XFP,
1225                                              0, sizeof(struct user_fxsr_struct),
1226                                              datap) ? -EIO : 0;
1227 #endif
1228
1229 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1230         case PTRACE_GET_THREAD_AREA:
1231                 if (addr < 0)
1232                         return -EIO;
1233                 ret = do_get_thread_area(child, addr,
1234                                          (struct user_desc __user *) data);
1235                 break;
1236
1237         case PTRACE_SET_THREAD_AREA:
1238                 if (addr < 0)
1239                         return -EIO;
1240                 ret = do_set_thread_area(child, addr,
1241                                          (struct user_desc __user *) data, 0);
1242                 break;
1243 #endif
1244
1245 #ifdef CONFIG_X86_64
1246                 /* normal 64bit interface to access TLS data.
1247                    Works just like arch_prctl, except that the arguments
1248                    are reversed. */
1249         case PTRACE_ARCH_PRCTL:
1250                 ret = do_arch_prctl(child, data, addr);
1251                 break;
1252 #endif
1253
1254         /*
1255          * These bits need more cooking - not enabled yet:
1256          */
1257 #ifdef CONFIG_X86_PTRACE_BTS
1258         case PTRACE_BTS_CONFIG:
1259                 ret = ptrace_bts_config
1260                         (child, data, (struct ptrace_bts_config __user *)addr);
1261                 break;
1262
1263         case PTRACE_BTS_STATUS:
1264                 ret = ptrace_bts_status
1265                         (child, data, (struct ptrace_bts_config __user *)addr);
1266                 break;
1267
1268         case PTRACE_BTS_SIZE:
1269                 ret = ptrace_bts_size(child);
1270                 break;
1271
1272         case PTRACE_BTS_GET:
1273                 ret = ptrace_bts_read_record
1274                         (child, data, (struct bts_struct __user *) addr);
1275                 break;
1276
1277         case PTRACE_BTS_CLEAR:
1278                 ret = ptrace_bts_clear(child);
1279                 break;
1280
1281         case PTRACE_BTS_DRAIN:
1282                 ret = ptrace_bts_drain
1283                         (child, data, (struct bts_struct __user *) addr);
1284                 break;
1285 #endif /* CONFIG_X86_PTRACE_BTS */
1286
1287         default:
1288                 ret = ptrace_request(child, request, addr, data);
1289                 break;
1290         }
1291
1292         return ret;
1293 }
1294
1295 #ifdef CONFIG_IA32_EMULATION
1296
1297 #include <linux/compat.h>
1298 #include <linux/syscalls.h>
1299 #include <asm/ia32.h>
1300 #include <asm/user32.h>
1301
1302 #define R32(l,q)                                                        \
1303         case offsetof(struct user32, regs.l):                           \
1304                 regs->q = value; break
1305
1306 #define SEG32(rs)                                                       \
1307         case offsetof(struct user32, regs.rs):                          \
1308                 return set_segment_reg(child,                           \
1309                                        offsetof(struct user_regs_struct, rs), \
1310                                        value);                          \
1311                 break
1312
1313 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
1314 {
1315         struct pt_regs *regs = task_pt_regs(child);
1316
1317         switch (regno) {
1318
1319         SEG32(cs);
1320         SEG32(ds);
1321         SEG32(es);
1322         SEG32(fs);
1323         SEG32(gs);
1324         SEG32(ss);
1325
1326         R32(ebx, bx);
1327         R32(ecx, cx);
1328         R32(edx, dx);
1329         R32(edi, di);
1330         R32(esi, si);
1331         R32(ebp, bp);
1332         R32(eax, ax);
1333         R32(eip, ip);
1334         R32(esp, sp);
1335
1336         case offsetof(struct user32, regs.orig_eax):
1337                 /*
1338                  * A 32-bit debugger setting orig_eax means to restore
1339                  * the state of the task restarting a 32-bit syscall.
1340                  * Make sure we interpret the -ERESTART* codes correctly
1341                  * in case the task is not actually still sitting at the
1342                  * exit from a 32-bit syscall with TS_COMPAT still set.
1343                  */
1344                 regs->orig_ax = value;
1345                 if (syscall_get_nr(child, regs) >= 0)
1346                         task_thread_info(child)->status |= TS_COMPAT;
1347                 break;
1348
1349         case offsetof(struct user32, regs.eflags):
1350                 return set_flags(child, value);
1351
1352         case offsetof(struct user32, u_debugreg[0]) ...
1353                 offsetof(struct user32, u_debugreg[7]):
1354                 regno -= offsetof(struct user32, u_debugreg[0]);
1355                 return ptrace_set_debugreg(child, regno / 4, value);
1356
1357         default:
1358                 if (regno > sizeof(struct user32) || (regno & 3))
1359                         return -EIO;
1360
1361                 /*
1362                  * Other dummy fields in the virtual user structure
1363                  * are ignored
1364                  */
1365                 break;
1366         }
1367         return 0;
1368 }
1369
1370 #undef R32
1371 #undef SEG32
1372
1373 #define R32(l,q)                                                        \
1374         case offsetof(struct user32, regs.l):                           \
1375                 *val = regs->q; break
1376
1377 #define SEG32(rs)                                                       \
1378         case offsetof(struct user32, regs.rs):                          \
1379                 *val = get_segment_reg(child,                           \
1380                                        offsetof(struct user_regs_struct, rs)); \
1381                 break
1382
1383 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1384 {
1385         struct pt_regs *regs = task_pt_regs(child);
1386
1387         switch (regno) {
1388
1389         SEG32(ds);
1390         SEG32(es);
1391         SEG32(fs);
1392         SEG32(gs);
1393
1394         R32(cs, cs);
1395         R32(ss, ss);
1396         R32(ebx, bx);
1397         R32(ecx, cx);
1398         R32(edx, dx);
1399         R32(edi, di);
1400         R32(esi, si);
1401         R32(ebp, bp);
1402         R32(eax, ax);
1403         R32(orig_eax, orig_ax);
1404         R32(eip, ip);
1405         R32(esp, sp);
1406
1407         case offsetof(struct user32, regs.eflags):
1408                 *val = get_flags(child);
1409                 break;
1410
1411         case offsetof(struct user32, u_debugreg[0]) ...
1412                 offsetof(struct user32, u_debugreg[7]):
1413                 regno -= offsetof(struct user32, u_debugreg[0]);
1414                 *val = ptrace_get_debugreg(child, regno / 4);
1415                 break;
1416
1417         default:
1418                 if (regno > sizeof(struct user32) || (regno & 3))
1419                         return -EIO;
1420
1421                 /*
1422                  * Other dummy fields in the virtual user structure
1423                  * are ignored
1424                  */
1425                 *val = 0;
1426                 break;
1427         }
1428         return 0;
1429 }
1430
1431 #undef R32
1432 #undef SEG32
1433
1434 static int genregs32_get(struct task_struct *target,
1435                          const struct user_regset *regset,
1436                          unsigned int pos, unsigned int count,
1437                          void *kbuf, void __user *ubuf)
1438 {
1439         if (kbuf) {
1440                 compat_ulong_t *k = kbuf;
1441                 while (count >= sizeof(*k)) {
1442                         getreg32(target, pos, k++);
1443                         count -= sizeof(*k);
1444                         pos += sizeof(*k);
1445                 }
1446         } else {
1447                 compat_ulong_t __user *u = ubuf;
1448                 while (count >= sizeof(*u)) {
1449                         compat_ulong_t word;
1450                         getreg32(target, pos, &word);
1451                         if (__put_user(word, u++))
1452                                 return -EFAULT;
1453                         count -= sizeof(*u);
1454                         pos += sizeof(*u);
1455                 }
1456         }
1457
1458         return 0;
1459 }
1460
1461 static int genregs32_set(struct task_struct *target,
1462                          const struct user_regset *regset,
1463                          unsigned int pos, unsigned int count,
1464                          const void *kbuf, const void __user *ubuf)
1465 {
1466         int ret = 0;
1467         if (kbuf) {
1468                 const compat_ulong_t *k = kbuf;
1469                 while (count >= sizeof(*k) && !ret) {
1470                         ret = putreg32(target, pos, *k++);
1471                         count -= sizeof(*k);
1472                         pos += sizeof(*k);
1473                 }
1474         } else {
1475                 const compat_ulong_t __user *u = ubuf;
1476                 while (count >= sizeof(*u) && !ret) {
1477                         compat_ulong_t word;
1478                         ret = __get_user(word, u++);
1479                         if (ret)
1480                                 break;
1481                         ret = putreg32(target, pos, word);
1482                         count -= sizeof(*u);
1483                         pos += sizeof(*u);
1484                 }
1485         }
1486         return ret;
1487 }
1488
1489 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1490                         compat_ulong_t caddr, compat_ulong_t cdata)
1491 {
1492         unsigned long addr = caddr;
1493         unsigned long data = cdata;
1494         void __user *datap = compat_ptr(data);
1495         int ret;
1496         __u32 val;
1497
1498         switch (request) {
1499         case PTRACE_PEEKUSR:
1500                 ret = getreg32(child, addr, &val);
1501                 if (ret == 0)
1502                         ret = put_user(val, (__u32 __user *)datap);
1503                 break;
1504
1505         case PTRACE_POKEUSR:
1506                 ret = putreg32(child, addr, data);
1507                 break;
1508
1509         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1510                 return copy_regset_to_user(child, &user_x86_32_view,
1511                                            REGSET_GENERAL,
1512                                            0, sizeof(struct user_regs_struct32),
1513                                            datap);
1514
1515         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1516                 return copy_regset_from_user(child, &user_x86_32_view,
1517                                              REGSET_GENERAL, 0,
1518                                              sizeof(struct user_regs_struct32),
1519                                              datap);
1520
1521         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1522                 return copy_regset_to_user(child, &user_x86_32_view,
1523                                            REGSET_FP, 0,
1524                                            sizeof(struct user_i387_ia32_struct),
1525                                            datap);
1526
1527         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1528                 return copy_regset_from_user(
1529                         child, &user_x86_32_view, REGSET_FP,
1530                         0, sizeof(struct user_i387_ia32_struct), datap);
1531
1532         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1533                 return copy_regset_to_user(child, &user_x86_32_view,
1534                                            REGSET_XFP, 0,
1535                                            sizeof(struct user32_fxsr_struct),
1536                                            datap);
1537
1538         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1539                 return copy_regset_from_user(child, &user_x86_32_view,
1540                                              REGSET_XFP, 0,
1541                                              sizeof(struct user32_fxsr_struct),
1542                                              datap);
1543
1544         case PTRACE_GET_THREAD_AREA:
1545         case PTRACE_SET_THREAD_AREA:
1546 #ifdef CONFIG_X86_PTRACE_BTS
1547         case PTRACE_BTS_CONFIG:
1548         case PTRACE_BTS_STATUS:
1549         case PTRACE_BTS_SIZE:
1550         case PTRACE_BTS_GET:
1551         case PTRACE_BTS_CLEAR:
1552         case PTRACE_BTS_DRAIN:
1553 #endif /* CONFIG_X86_PTRACE_BTS */
1554                 return arch_ptrace(child, request, addr, data);
1555
1556         default:
1557                 return compat_ptrace_request(child, request, addr, data);
1558         }
1559
1560         return ret;
1561 }
1562
1563 #endif  /* CONFIG_IA32_EMULATION */
1564
1565 #ifdef CONFIG_X86_64
1566
1567 static struct user_regset x86_64_regsets[] __read_mostly = {
1568         [REGSET_GENERAL] = {
1569                 .core_note_type = NT_PRSTATUS,
1570                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1571                 .size = sizeof(long), .align = sizeof(long),
1572                 .get = genregs_get, .set = genregs_set
1573         },
1574         [REGSET_FP] = {
1575                 .core_note_type = NT_PRFPREG,
1576                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1577                 .size = sizeof(long), .align = sizeof(long),
1578                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1579         },
1580         [REGSET_XSTATE] = {
1581                 .core_note_type = NT_X86_XSTATE,
1582                 .size = sizeof(u64), .align = sizeof(u64),
1583                 .active = xstateregs_active, .get = xstateregs_get,
1584                 .set = xstateregs_set
1585         },
1586         [REGSET_IOPERM64] = {
1587                 .core_note_type = NT_386_IOPERM,
1588                 .n = IO_BITMAP_LONGS,
1589                 .size = sizeof(long), .align = sizeof(long),
1590                 .active = ioperm_active, .get = ioperm_get
1591         },
1592 };
1593
1594 static const struct user_regset_view user_x86_64_view = {
1595         .name = "x86_64", .e_machine = EM_X86_64,
1596         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1597 };
1598
1599 #else  /* CONFIG_X86_32 */
1600
1601 #define user_regs_struct32      user_regs_struct
1602 #define genregs32_get           genregs_get
1603 #define genregs32_set           genregs_set
1604
1605 #define user_i387_ia32_struct   user_i387_struct
1606 #define user32_fxsr_struct      user_fxsr_struct
1607
1608 #endif  /* CONFIG_X86_64 */
1609
1610 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1611 static struct user_regset x86_32_regsets[] __read_mostly = {
1612         [REGSET_GENERAL] = {
1613                 .core_note_type = NT_PRSTATUS,
1614                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1615                 .size = sizeof(u32), .align = sizeof(u32),
1616                 .get = genregs32_get, .set = genregs32_set
1617         },
1618         [REGSET_FP] = {
1619                 .core_note_type = NT_PRFPREG,
1620                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1621                 .size = sizeof(u32), .align = sizeof(u32),
1622                 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1623         },
1624         [REGSET_XFP] = {
1625                 .core_note_type = NT_PRXFPREG,
1626                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1627                 .size = sizeof(u32), .align = sizeof(u32),
1628                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1629         },
1630         [REGSET_XSTATE] = {
1631                 .core_note_type = NT_X86_XSTATE,
1632                 .size = sizeof(u64), .align = sizeof(u64),
1633                 .active = xstateregs_active, .get = xstateregs_get,
1634                 .set = xstateregs_set
1635         },
1636         [REGSET_TLS] = {
1637                 .core_note_type = NT_386_TLS,
1638                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1639                 .size = sizeof(struct user_desc),
1640                 .align = sizeof(struct user_desc),
1641                 .active = regset_tls_active,
1642                 .get = regset_tls_get, .set = regset_tls_set
1643         },
1644         [REGSET_IOPERM32] = {
1645                 .core_note_type = NT_386_IOPERM,
1646                 .n = IO_BITMAP_BYTES / sizeof(u32),
1647                 .size = sizeof(u32), .align = sizeof(u32),
1648                 .active = ioperm_active, .get = ioperm_get
1649         },
1650 };
1651
1652 static const struct user_regset_view user_x86_32_view = {
1653         .name = "i386", .e_machine = EM_386,
1654         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1655 };
1656 #endif
1657
1658 /*
1659  * This represents bytes 464..511 in the memory layout exported through
1660  * the REGSET_XSTATE interface.
1661  */
1662 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1663
1664 void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1665 {
1666 #ifdef CONFIG_X86_64
1667         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1668 #endif
1669 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1670         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1671 #endif
1672         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1673 }
1674
1675 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1676 {
1677 #ifdef CONFIG_IA32_EMULATION
1678         if (test_tsk_thread_flag(task, TIF_IA32))
1679 #endif
1680 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1681                 return &user_x86_32_view;
1682 #endif
1683 #ifdef CONFIG_X86_64
1684         return &user_x86_64_view;
1685 #endif
1686 }
1687
1688 static void fill_sigtrap_info(struct task_struct *tsk,
1689                                 struct pt_regs *regs,
1690                                 int error_code, int si_code,
1691                                 struct siginfo *info)
1692 {
1693         tsk->thread.trap_no = 1;
1694         tsk->thread.error_code = error_code;
1695
1696         memset(info, 0, sizeof(*info));
1697         info->si_signo = SIGTRAP;
1698         info->si_code = si_code;
1699         info->si_addr = user_mode_vm(regs) ? (void __user *)regs->ip : NULL;
1700 }
1701
1702 void user_single_step_siginfo(struct task_struct *tsk,
1703                                 struct pt_regs *regs,
1704                                 struct siginfo *info)
1705 {
1706         fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1707 }
1708
1709 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1710                                          int error_code, int si_code)
1711 {
1712         struct siginfo info;
1713
1714         fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1715         /* Send us the fake SIGTRAP */
1716         force_sig_info(SIGTRAP, &info, tsk);
1717 }
1718
1719
1720 #ifdef CONFIG_X86_32
1721 # define IS_IA32        1
1722 #elif defined CONFIG_IA32_EMULATION
1723 # define IS_IA32        is_compat_task()
1724 #else
1725 # define IS_IA32        0
1726 #endif
1727
1728 /*
1729  * We must return the syscall number to actually look up in the table.
1730  * This can be -1L to skip running any syscall at all.
1731  */
1732 asmregparm long syscall_trace_enter(struct pt_regs *regs)
1733 {
1734         long ret = 0;
1735
1736         /*
1737          * If we stepped into a sysenter/syscall insn, it trapped in
1738          * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1739          * If user-mode had set TF itself, then it's still clear from
1740          * do_debug() and we need to set it again to restore the user
1741          * state.  If we entered on the slow path, TF was already set.
1742          */
1743         if (test_thread_flag(TIF_SINGLESTEP))
1744                 regs->flags |= X86_EFLAGS_TF;
1745
1746         /* do the secure computing check first */
1747         secure_computing(regs->orig_ax);
1748
1749         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1750                 ret = -1L;
1751
1752         if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1753             tracehook_report_syscall_entry(regs))
1754                 ret = -1L;
1755
1756         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1757                 trace_sys_enter(regs, regs->orig_ax);
1758
1759         if (unlikely(current->audit_context)) {
1760                 if (IS_IA32)
1761                         audit_syscall_entry(AUDIT_ARCH_I386,
1762                                             regs->orig_ax,
1763                                             regs->bx, regs->cx,
1764                                             regs->dx, regs->si);
1765 #ifdef CONFIG_X86_64
1766                 else
1767                         audit_syscall_entry(AUDIT_ARCH_X86_64,
1768                                             regs->orig_ax,
1769                                             regs->di, regs->si,
1770                                             regs->dx, regs->r10);
1771 #endif
1772         }
1773
1774         return ret ?: regs->orig_ax;
1775 }
1776
1777 asmregparm void syscall_trace_leave(struct pt_regs *regs)
1778 {
1779         bool step;
1780
1781         if (unlikely(current->audit_context))
1782                 audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
1783
1784         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1785                 trace_sys_exit(regs, regs->ax);
1786
1787         /*
1788          * If TIF_SYSCALL_EMU is set, we only get here because of
1789          * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1790          * We already reported this syscall instruction in
1791          * syscall_trace_enter().
1792          */
1793         step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
1794                         !test_thread_flag(TIF_SYSCALL_EMU);
1795         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1796                 tracehook_report_syscall_exit(regs, step);
1797 }