Pileus Git - ~andy/linux/blob - arch/arm/kernel/ptrace.c

   1 /*
   2  *  linux/arch/arm/kernel/ptrace.c
   3  *
   4  *  By Ross Biro 1/23/92
   5  * edited by Linus Torvalds
   6  * ARM modifications Copyright (C) 2000 Russell King
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12 #include <linux/kernel.h>
  13 #include <linux/sched.h>
  14 #include <linux/mm.h>
  15 #include <linux/elf.h>
  16 #include <linux/smp.h>
  17 #include <linux/ptrace.h>
  18 #include <linux/user.h>
  19 #include <linux/security.h>
  20 #include <linux/init.h>
  21 #include <linux/signal.h>
  22 #include <linux/uaccess.h>
  23 #include <linux/perf_event.h>
  24 #include <linux/hw_breakpoint.h>
  25 #include <linux/regset.h>
  26 #include <linux/audit.h>
  27 #include <linux/tracehook.h>
  28 #include <linux/unistd.h>
  29
  30 #include <asm/pgtable.h>
  31 #include <asm/traps.h>
  32
  33 #define REG_PC  15
  34 #define REG_PSR 16
  35 /*
  36  * does not yet catch signals sent when the child dies.
  37  * in exit.c or in signal.c.
  38  */
  39
  40 #if 0
  41 /*
  42  * Breakpoint SWI instruction: SWI &9F0001
  43  */
  44 #define BREAKINST_ARM   0xef9f0001
  45 #define BREAKINST_THUMB 0xdf00          /* fill this in later */
  46 #else
  47 /*
  48  * New breakpoints - use an undefined instruction.  The ARM architecture
  49  * reference manual guarantees that the following instruction space
  50  * will produce an undefined instruction exception on all CPUs:
  51  *
  52  *  ARM:   xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx
  53  *  Thumb: 1101 1110 xxxx xxxx
  54  */
  55 #define BREAKINST_ARM   0xe7f001f0
  56 #define BREAKINST_THUMB 0xde01
  57 #endif
  58
  59 struct pt_regs_offset {
  60         const char *name;
  61         int offset;
  62 };
  63
  64 #define REG_OFFSET_NAME(r) \
  65         {.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)}
  66 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  67
  68 static const struct pt_regs_offset regoffset_table[] = {
  69         REG_OFFSET_NAME(r0),
  70         REG_OFFSET_NAME(r1),
  71         REG_OFFSET_NAME(r2),
  72         REG_OFFSET_NAME(r3),
  73         REG_OFFSET_NAME(r4),
  74         REG_OFFSET_NAME(r5),
  75         REG_OFFSET_NAME(r6),
  76         REG_OFFSET_NAME(r7),
  77         REG_OFFSET_NAME(r8),
  78         REG_OFFSET_NAME(r9),
  79         REG_OFFSET_NAME(r10),
  80         REG_OFFSET_NAME(fp),
  81         REG_OFFSET_NAME(ip),
  82         REG_OFFSET_NAME(sp),
  83         REG_OFFSET_NAME(lr),
  84         REG_OFFSET_NAME(pc),
  85         REG_OFFSET_NAME(cpsr),
  86         REG_OFFSET_NAME(ORIG_r0),
  87         REG_OFFSET_END,
  88 };
  89
  90 /**
  91  * regs_query_register_offset() - query register offset from its name
  92  * @name:       the name of a register
  93  *
  94  * regs_query_register_offset() returns the offset of a register in struct
  95  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
  96  */
  97 int regs_query_register_offset(const char *name)
  98 {
  99         const struct pt_regs_offset *roff;
 100         for (roff = regoffset_table; roff->name != NULL; roff++)
 101                 if (!strcmp(roff->name, name))
 102                         return roff->offset;
 103         return -EINVAL;
 104 }
 105
 106 /**
 107  * regs_query_register_name() - query register name from its offset
 108  * @offset:     the offset of a register in struct pt_regs.
 109  *
 110  * regs_query_register_name() returns the name of a register from its
 111  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 112  */
 113 const char *regs_query_register_name(unsigned int offset)
 114 {
 115         const struct pt_regs_offset *roff;
 116         for (roff = regoffset_table; roff->name != NULL; roff++)
 117                 if (roff->offset == offset)
 118                         return roff->name;
 119         return NULL;
 120 }
 121
 122 /**
 123  * regs_within_kernel_stack() - check the address in the stack
 124  * @regs:      pt_regs which contains kernel stack pointer.
 125  * @addr:      address which is checked.
 126  *
 127  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 128  * If @addr is within the kernel stack, it returns true. If not, returns false.
 129  */
 130 bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 131 {
 132         return ((addr & ~(THREAD_SIZE - 1))  ==
 133                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
 134 }
 135
 136 /**
 137  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 138  * @regs:       pt_regs which contains kernel stack pointer.
 139  * @n:          stack entry number.
 140  *
 141  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 142  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 143  * this returns 0.
 144  */
 145 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 146 {
 147         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 148         addr += n;
 149         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 150                 return *addr;
 151         else
 152                 return 0;
 153 }
 154
 155 /*
 156  * this routine will get a word off of the processes privileged stack.
 157  * the offset is how far from the base addr as stored in the THREAD.
 158  * this routine assumes that all the privileged stacks are in our
 159  * data space.
 160  */
 161 static inline long get_user_reg(struct task_struct *task, int offset)
 162 {
 163         return task_pt_regs(task)->uregs[offset];
 164 }
 165
 166 /*
 167  * this routine will put a word on the processes privileged stack.
 168  * the offset is how far from the base addr as stored in the THREAD.
 169  * this routine assumes that all the privileged stacks are in our
 170  * data space.
 171  */
 172 static inline int
 173 put_user_reg(struct task_struct *task, int offset, long data)
 174 {
 175         struct pt_regs newregs, *regs = task_pt_regs(task);
 176         int ret = -EINVAL;
 177
 178         newregs = *regs;
 179         newregs.uregs[offset] = data;
 180
 181         if (valid_user_regs(&newregs)) {
 182                 regs->uregs[offset] = data;
 183                 ret = 0;
 184         }
 185
 186         return ret;
 187 }
 188
 189 /*
 190  * Called by kernel/ptrace.c when detaching..
 191  */
 192 void ptrace_disable(struct task_struct *child)
 193 {
 194         /* Nothing to do. */
 195 }
 196
 197 /*
 198  * Handle hitting a breakpoint.
 199  */
 200 void ptrace_break(struct task_struct *tsk, struct pt_regs *regs)
 201 {
 202         siginfo_t info;
 203
 204         info.si_signo = SIGTRAP;
 205         info.si_errno = 0;
 206         info.si_code  = TRAP_BRKPT;
 207         info.si_addr  = (void __user *)instruction_pointer(regs);
 208
 209         force_sig_info(SIGTRAP, &info, tsk);
 210 }
 211
 212 static int break_trap(struct pt_regs *regs, unsigned int instr)
 213 {
 214         ptrace_break(current, regs);
 215         return 0;
 216 }
 217
 218 static struct undef_hook arm_break_hook = {
 219         .instr_mask     = 0x0fffffff,
 220         .instr_val      = 0x07f001f0,
 221         .cpsr_mask      = PSR_T_BIT,
 222         .cpsr_val       = 0,
 223         .fn             = break_trap,
 224 };
 225
 226 static struct undef_hook thumb_break_hook = {
 227         .instr_mask     = 0xffff,
 228         .instr_val      = 0xde01,
 229         .cpsr_mask      = PSR_T_BIT,
 230         .cpsr_val       = PSR_T_BIT,
 231         .fn             = break_trap,
 232 };
 233
 234 static struct undef_hook thumb2_break_hook = {
 235         .instr_mask     = 0xffffffff,
 236         .instr_val      = 0xf7f0a000,
 237         .cpsr_mask      = PSR_T_BIT,
 238         .cpsr_val       = PSR_T_BIT,
 239         .fn             = break_trap,
 240 };
 241
 242 static int __init ptrace_break_init(void)
 243 {
 244         register_undef_hook(&arm_break_hook);
 245         register_undef_hook(&thumb_break_hook);
 246         register_undef_hook(&thumb2_break_hook);
 247         return 0;
 248 }
 249
 250 core_initcall(ptrace_break_init);
 251
 252 /*
 253  * Read the word at offset "off" into the "struct user".  We
 254  * actually access the pt_regs stored on the kernel stack.
 255  */
 256 static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
 257                             unsigned long __user *ret)
 258 {
 259         unsigned long tmp;
 260
 261         if (off & 3)
 262                 return -EIO;
 263
 264         tmp = 0;
 265         if (off == PT_TEXT_ADDR)
 266                 tmp = tsk->mm->start_code;
 267         else if (off == PT_DATA_ADDR)
 268                 tmp = tsk->mm->start_data;
 269         else if (off == PT_TEXT_END_ADDR)
 270                 tmp = tsk->mm->end_code;
 271         else if (off < sizeof(struct pt_regs))
 272                 tmp = get_user_reg(tsk, off >> 2);
 273         else if (off >= sizeof(struct user))
 274                 return -EIO;
 275
 276         return put_user(tmp, ret);
 277 }
 278
 279 /*
 280  * Write the word at offset "off" into "struct user".  We
 281  * actually access the pt_regs stored on the kernel stack.
 282  */
 283 static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
 284                              unsigned long val)
 285 {
 286         if (off & 3 || off >= sizeof(struct user))
 287                 return -EIO;
 288
 289         if (off >= sizeof(struct pt_regs))
 290                 return 0;
 291
 292         return put_user_reg(tsk, off >> 2, val);
 293 }
 294
 295 #ifdef CONFIG_IWMMXT
 296
 297 /*
 298  * Get the child iWMMXt state.
 299  */
 300 static int ptrace_getwmmxregs(struct task_struct *tsk, void __user *ufp)
 301 {
 302         struct thread_info *thread = task_thread_info(tsk);
 303
 304         if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
 305                 return -ENODATA;
 306         iwmmxt_task_disable(thread);  /* force it to ram */
 307         return copy_to_user(ufp, &thread->fpstate.iwmmxt, IWMMXT_SIZE)
 308                 ? -EFAULT : 0;
 309 }
 310
 311 /*
 312  * Set the child iWMMXt state.
 313  */
 314 static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp)
 315 {
 316         struct thread_info *thread = task_thread_info(tsk);
 317
 318         if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
 319                 return -EACCES;
 320         iwmmxt_task_release(thread);  /* force a reload */
 321         return copy_from_user(&thread->fpstate.iwmmxt, ufp, IWMMXT_SIZE)
 322                 ? -EFAULT : 0;
 323 }
 324
 325 #endif
 326
 327 #ifdef CONFIG_CRUNCH
 328 /*
 329  * Get the child Crunch state.
 330  */
 331 static int ptrace_getcrunchregs(struct task_struct *tsk, void __user *ufp)
 332 {
 333         struct thread_info *thread = task_thread_info(tsk);
 334
 335         crunch_task_disable(thread);  /* force it to ram */
 336         return copy_to_user(ufp, &thread->crunchstate, CRUNCH_SIZE)
 337                 ? -EFAULT : 0;
 338 }
 339
 340 /*
 341  * Set the child Crunch state.
 342  */
 343 static int ptrace_setcrunchregs(struct task_struct *tsk, void __user *ufp)
 344 {
 345         struct thread_info *thread = task_thread_info(tsk);
 346
 347         crunch_task_release(thread);  /* force a reload */
 348         return copy_from_user(&thread->crunchstate, ufp, CRUNCH_SIZE)
 349                 ? -EFAULT : 0;
 350 }
 351 #endif
 352
 353 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 354 /*
 355  * Convert a virtual register number into an index for a thread_info
 356  * breakpoint array. Breakpoints are identified using positive numbers
 357  * whilst watchpoints are negative. The registers are laid out as pairs
 358  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
 359  * Register 0 is reserved for describing resource information.
 360  */
 361 static int ptrace_hbp_num_to_idx(long num)
 362 {
 363         if (num < 0)
 364                 num = (ARM_MAX_BRP << 1) - num;
 365         return (num - 1) >> 1;
 366 }
 367
 368 /*
 369  * Returns the virtual register number for the address of the
 370  * breakpoint at index idx.
 371  */
 372 static long ptrace_hbp_idx_to_num(int idx)
 373 {
 374         long mid = ARM_MAX_BRP << 1;
 375         long num = (idx << 1) + 1;
 376         return num > mid ? mid - num : num;
 377 }
 378
 379 /*
 380  * Handle hitting a HW-breakpoint.
 381  */
 382 static void ptrace_hbptriggered(struct perf_event *bp,
 383                                      struct perf_sample_data *data,
 384                                      struct pt_regs *regs)
 385 {
 386         struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
 387         long num;
 388         int i;
 389         siginfo_t info;
 390
 391         for (i = 0; i < ARM_MAX_HBP_SLOTS; ++i)
 392                 if (current->thread.debug.hbp[i] == bp)
 393                         break;
 394
 395         num = (i == ARM_MAX_HBP_SLOTS) ? 0 : ptrace_hbp_idx_to_num(i);
 396
 397         info.si_signo   = SIGTRAP;
 398         info.si_errno   = (int)num;
 399         info.si_code    = TRAP_HWBKPT;
 400         info.si_addr    = (void __user *)(bkpt->trigger);
 401
 402         force_sig_info(SIGTRAP, &info, current);
 403 }
 404
 405 /*
 406  * Set ptrace breakpoint pointers to zero for this task.
 407  * This is required in order to prevent child processes from unregistering
 408  * breakpoints held by their parent.
 409  */
 410 void clear_ptrace_hw_breakpoint(struct task_struct *tsk)
 411 {
 412         memset(tsk->thread.debug.hbp, 0, sizeof(tsk->thread.debug.hbp));
 413 }
 414
 415 /*
 416  * Unregister breakpoints from this task and reset the pointers in
 417  * the thread_struct.
 418  */
 419 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 420 {
 421         int i;
 422         struct thread_struct *t = &tsk->thread;
 423
 424         for (i = 0; i < ARM_MAX_HBP_SLOTS; i++) {
 425                 if (t->debug.hbp[i]) {
 426                         unregister_hw_breakpoint(t->debug.hbp[i]);
 427                         t->debug.hbp[i] = NULL;
 428                 }
 429         }
 430 }
 431
 432 static u32 ptrace_get_hbp_resource_info(void)
 433 {
 434         u8 num_brps, num_wrps, debug_arch, wp_len;
 435         u32 reg = 0;
 436
 437         num_brps        = hw_breakpoint_slots(TYPE_INST);
 438         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
 439         debug_arch      = arch_get_debug_arch();
 440         wp_len          = arch_get_max_wp_len();
 441
 442         reg             |= debug_arch;
 443         reg             <<= 8;
 444         reg             |= wp_len;
 445         reg             <<= 8;
 446         reg             |= num_wrps;
 447         reg             <<= 8;
 448         reg             |= num_brps;
 449
 450         return reg;
 451 }
 452
 453 static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
 454 {
 455         struct perf_event_attr attr;
 456
 457         ptrace_breakpoint_init(&attr);
 458
 459         /* Initialise fields to sane defaults. */
 460         attr.bp_addr    = 0;
 461         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 462         attr.bp_type    = type;
 463         attr.disabled   = 1;
 464
 465         return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL,
 466                                            tsk);
 467 }
 468
 469 static int ptrace_gethbpregs(struct task_struct *tsk, long num,
 470                              unsigned long  __user *data)
 471 {
 472         u32 reg;
 473         int idx, ret = 0;
 474         struct perf_event *bp;
 475         struct arch_hw_breakpoint_ctrl arch_ctrl;
 476
 477         if (num == 0) {
 478                 reg = ptrace_get_hbp_resource_info();
 479         } else {
 480                 idx = ptrace_hbp_num_to_idx(num);
 481                 if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
 482                         ret = -EINVAL;
 483                         goto out;
 484                 }
 485
 486                 bp = tsk->thread.debug.hbp[idx];
 487                 if (!bp) {
 488                         reg = 0;
 489                         goto put;
 490                 }
 491
 492                 arch_ctrl = counter_arch_bp(bp)->ctrl;
 493
 494                 /*
 495                  * Fix up the len because we may have adjusted it
 496                  * to compensate for an unaligned address.
 497                  */
 498                 while (!(arch_ctrl.len & 0x1))
 499                         arch_ctrl.len >>= 1;
 500
 501                 if (num & 0x1)
 502                         reg = bp->attr.bp_addr;
 503                 else
 504                         reg = encode_ctrl_reg(arch_ctrl);
 505         }
 506
 507 put:
 508         if (put_user(reg, data))
 509                 ret = -EFAULT;
 510
 511 out:
 512         return ret;
 513 }
 514
 515 static int ptrace_sethbpregs(struct task_struct *tsk, long num,
 516                              unsigned long __user *data)
 517 {
 518         int idx, gen_len, gen_type, implied_type, ret = 0;
 519         u32 user_val;
 520         struct perf_event *bp;
 521         struct arch_hw_breakpoint_ctrl ctrl;
 522         struct perf_event_attr attr;
 523
 524         if (num == 0)
 525                 goto out;
 526         else if (num < 0)
 527                 implied_type = HW_BREAKPOINT_RW;
 528         else
 529                 implied_type = HW_BREAKPOINT_X;
 530
 531         idx = ptrace_hbp_num_to_idx(num);
 532         if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
 533                 ret = -EINVAL;
 534                 goto out;
 535         }
 536
 537         if (get_user(user_val, data)) {
 538                 ret = -EFAULT;
 539                 goto out;
 540         }
 541
 542         bp = tsk->thread.debug.hbp[idx];
 543         if (!bp) {
 544                 bp = ptrace_hbp_create(tsk, implied_type);
 545                 if (IS_ERR(bp)) {
 546                         ret = PTR_ERR(bp);
 547                         goto out;
 548                 }
 549                 tsk->thread.debug.hbp[idx] = bp;
 550         }
 551
 552         attr = bp->attr;
 553
 554         if (num & 0x1) {
 555                 /* Address */
 556                 attr.bp_addr    = user_val;
 557         } else {
 558                 /* Control */
 559                 decode_ctrl_reg(user_val, &ctrl);
 560                 ret = arch_bp_generic_fields(ctrl, &gen_len, &gen_type);
 561                 if (ret)
 562                         goto out;
 563
 564                 if ((gen_type & implied_type) != gen_type) {
 565                         ret = -EINVAL;
 566                         goto out;
 567                 }
 568
 569                 attr.bp_len     = gen_len;
 570                 attr.bp_type    = gen_type;
 571                 attr.disabled   = !ctrl.enabled;
 572         }
 573
 574         ret = modify_user_hw_breakpoint(bp, &attr);
 575 out:
 576         return ret;
 577 }
 578 #endif
 579
 580 /* regset get/set implementations */
 581
 582 static int gpr_get(struct task_struct *target,
 583                    const struct user_regset *regset,
 584                    unsigned int pos, unsigned int count,
 585                    void *kbuf, void __user *ubuf)
 586 {
 587         struct pt_regs *regs = task_pt_regs(target);
 588
 589         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 590                                    regs,
 591                                    0, sizeof(*regs));
 592 }
 593
 594 static int gpr_set(struct task_struct *target,
 595                    const struct user_regset *regset,
 596                    unsigned int pos, unsigned int count,
 597                    const void *kbuf, const void __user *ubuf)
 598 {
 599         int ret;
 600         struct pt_regs newregs;
 601
 602         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 603                                  &newregs,
 604                                  0, sizeof(newregs));
 605         if (ret)
 606                 return ret;
 607
 608         if (!valid_user_regs(&newregs))
 609                 return -EINVAL;
 610
 611         *task_pt_regs(target) = newregs;
 612         return 0;
 613 }
 614
 615 static int fpa_get(struct task_struct *target,
 616                    const struct user_regset *regset,
 617                    unsigned int pos, unsigned int count,
 618                    void *kbuf, void __user *ubuf)
 619 {
 620         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 621                                    &task_thread_info(target)->fpstate,
 622                                    0, sizeof(struct user_fp));
 623 }
 624
 625 static int fpa_set(struct task_struct *target,
 626                    const struct user_regset *regset,
 627                    unsigned int pos, unsigned int count,
 628                    const void *kbuf, const void __user *ubuf)
 629 {
 630         struct thread_info *thread = task_thread_info(target);
 631
 632         thread->used_cp[1] = thread->used_cp[2] = 1;
 633
 634         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 635                 &thread->fpstate,
 636                 0, sizeof(struct user_fp));
 637 }
 638
 639 #ifdef CONFIG_VFP
 640 /*
 641  * VFP register get/set implementations.
 642  *
 643  * With respect to the kernel, struct user_fp is divided into three chunks:
 644  * 16 or 32 real VFP registers (d0-d15 or d0-31)
 645  *      These are transferred to/from the real registers in the task's
 646  *      vfp_hard_struct.  The number of registers depends on the kernel
 647  *      configuration.
 648  *
 649  * 16 or 0 fake VFP registers (d16-d31 or empty)
 650  *      i.e., the user_vfp structure has space for 32 registers even if
 651  *      the kernel doesn't have them all.
 652  *
 653  *      vfp_get() reads this chunk as zero where applicable
 654  *      vfp_set() ignores this chunk
 655  *
 656  * 1 word for the FPSCR
 657  *
 658  * The bounds-checking logic built into user_regset_copyout and friends
 659  * means that we can make a simple sequence of calls to map the relevant data
 660  * to/from the specified slice of the user regset structure.
 661  */
 662 static int vfp_get(struct task_struct *target,
 663                    const struct user_regset *regset,
 664                    unsigned int pos, unsigned int count,
 665                    void *kbuf, void __user *ubuf)
 666 {
 667         int ret;
 668         struct thread_info *thread = task_thread_info(target);
 669         struct vfp_hard_struct const *vfp = &thread->vfpstate.hard;
 670         const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
 671         const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
 672
 673         vfp_sync_hwstate(thread);
 674
 675         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 676                                   &vfp->fpregs,
 677                                   user_fpregs_offset,
 678                                   user_fpregs_offset + sizeof(vfp->fpregs));
 679         if (ret)
 680                 return ret;
 681
 682         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 683                                        user_fpregs_offset + sizeof(vfp->fpregs),
 684                                        user_fpscr_offset);
 685         if (ret)
 686                 return ret;
 687
 688         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 689                                    &vfp->fpscr,
 690                                    user_fpscr_offset,
 691                                    user_fpscr_offset + sizeof(vfp->fpscr));
 692 }
 693
 694 /*
 695  * For vfp_set() a read-modify-write is done on the VFP registers,
 696  * in order to avoid writing back a half-modified set of registers on
 697  * failure.
 698  */
 699 static int vfp_set(struct task_struct *target,
 700                           const struct user_regset *regset,
 701                           unsigned int pos, unsigned int count,
 702                           const void *kbuf, const void __user *ubuf)
 703 {
 704         int ret;
 705         struct thread_info *thread = task_thread_info(target);
 706         struct vfp_hard_struct new_vfp;
 707         const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
 708         const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
 709
 710         vfp_sync_hwstate(thread);
 711         new_vfp = thread->vfpstate.hard;
 712
 713         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 714                                   &new_vfp.fpregs,
 715                                   user_fpregs_offset,
 716                                   user_fpregs_offset + sizeof(new_vfp.fpregs));
 717         if (ret)
 718                 return ret;
 719
 720         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 721                                 user_fpregs_offset + sizeof(new_vfp.fpregs),
 722                                 user_fpscr_offset);
 723         if (ret)
 724                 return ret;
 725
 726         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 727                                  &new_vfp.fpscr,
 728                                  user_fpscr_offset,
 729                                  user_fpscr_offset + sizeof(new_vfp.fpscr));
 730         if (ret)
 731                 return ret;
 732
 733         vfp_flush_hwstate(thread);
 734         thread->vfpstate.hard = new_vfp;
 735
 736         return 0;
 737 }
 738 #endif /* CONFIG_VFP */
 739
 740 enum arm_regset {
 741         REGSET_GPR,
 742         REGSET_FPR,
 743 #ifdef CONFIG_VFP
 744         REGSET_VFP,
 745 #endif
 746 };
 747
 748 static const struct user_regset arm_regsets[] = {
 749         [REGSET_GPR] = {
 750                 .core_note_type = NT_PRSTATUS,
 751                 .n = ELF_NGREG,
 752                 .size = sizeof(u32),
 753                 .align = sizeof(u32),
 754                 .get = gpr_get,
 755                 .set = gpr_set
 756         },
 757         [REGSET_FPR] = {
 758                 /*
 759                  * For the FPA regs in fpstate, the real fields are a mixture
 760                  * of sizes, so pretend that the registers are word-sized:
 761                  */
 762                 .core_note_type = NT_PRFPREG,
 763                 .n = sizeof(struct user_fp) / sizeof(u32),
 764                 .size = sizeof(u32),
 765                 .align = sizeof(u32),
 766                 .get = fpa_get,
 767                 .set = fpa_set
 768         },
 769 #ifdef CONFIG_VFP
 770         [REGSET_VFP] = {
 771                 /*
 772                  * Pretend that the VFP regs are word-sized, since the FPSCR is
 773                  * a single word dangling at the end of struct user_vfp:
 774                  */
 775                 .core_note_type = NT_ARM_VFP,
 776                 .n = ARM_VFPREGS_SIZE / sizeof(u32),
 777                 .size = sizeof(u32),
 778                 .align = sizeof(u32),
 779                 .get = vfp_get,
 780                 .set = vfp_set
 781         },
 782 #endif /* CONFIG_VFP */
 783 };
 784
 785 static const struct user_regset_view user_arm_view = {
 786         .name = "arm", .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI,
 787         .regsets = arm_regsets, .n = ARRAY_SIZE(arm_regsets)
 788 };
 789
 790 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 791 {
 792         return &user_arm_view;
 793 }
 794
 795 long arch_ptrace(struct task_struct *child, long request,
 796                  unsigned long addr, unsigned long data)
 797 {
 798         int ret;
 799         unsigned long __user *datap = (unsigned long __user *) data;
 800
 801         switch (request) {
 802                 case PTRACE_PEEKUSR:
 803                         ret = ptrace_read_user(child, addr, datap);
 804                         break;
 805
 806                 case PTRACE_POKEUSR:
 807                         ret = ptrace_write_user(child, addr, data);
 808                         break;
 809
 810                 case PTRACE_GETREGS:
 811                         ret = copy_regset_to_user(child,
 812                                                   &user_arm_view, REGSET_GPR,
 813                                                   0, sizeof(struct pt_regs),
 814                                                   datap);
 815                         break;
 816
 817                 case PTRACE_SETREGS:
 818                         ret = copy_regset_from_user(child,
 819                                                     &user_arm_view, REGSET_GPR,
 820                                                     0, sizeof(struct pt_regs),
 821                                                     datap);
 822                         break;
 823
 824                 case PTRACE_GETFPREGS:
 825                         ret = copy_regset_to_user(child,
 826                                                   &user_arm_view, REGSET_FPR,
 827                                                   0, sizeof(union fp_state),
 828                                                   datap);
 829                         break;
 830
 831                 case PTRACE_SETFPREGS:
 832                         ret = copy_regset_from_user(child,
 833                                                     &user_arm_view, REGSET_FPR,
 834                                                     0, sizeof(union fp_state),
 835                                                     datap);
 836                         break;
 837
 838 #ifdef CONFIG_IWMMXT
 839                 case PTRACE_GETWMMXREGS:
 840                         ret = ptrace_getwmmxregs(child, datap);
 841                         break;
 842
 843                 case PTRACE_SETWMMXREGS:
 844                         ret = ptrace_setwmmxregs(child, datap);
 845                         break;
 846 #endif
 847
 848                 case PTRACE_GET_THREAD_AREA:
 849                         ret = put_user(task_thread_info(child)->tp_value,
 850                                        datap);
 851                         break;
 852
 853                 case PTRACE_SET_SYSCALL:
 854                         task_thread_info(child)->syscall = data;
 855                         ret = 0;
 856                         break;
 857
 858 #ifdef CONFIG_CRUNCH
 859                 case PTRACE_GETCRUNCHREGS:
 860                         ret = ptrace_getcrunchregs(child, datap);
 861                         break;
 862
 863                 case PTRACE_SETCRUNCHREGS:
 864                         ret = ptrace_setcrunchregs(child, datap);
 865                         break;
 866 #endif
 867
 868 #ifdef CONFIG_VFP
 869                 case PTRACE_GETVFPREGS:
 870                         ret = copy_regset_to_user(child,
 871                                                   &user_arm_view, REGSET_VFP,
 872                                                   0, ARM_VFPREGS_SIZE,
 873                                                   datap);
 874                         break;
 875
 876                 case PTRACE_SETVFPREGS:
 877                         ret = copy_regset_from_user(child,
 878                                                     &user_arm_view, REGSET_VFP,
 879                                                     0, ARM_VFPREGS_SIZE,
 880                                                     datap);
 881                         break;
 882 #endif
 883
 884 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 885                 case PTRACE_GETHBPREGS:
 886                         if (ptrace_get_breakpoints(child) < 0)
 887                                 return -ESRCH;
 888
 889                         ret = ptrace_gethbpregs(child, addr,
 890                                                 (unsigned long __user *)data);
 891                         ptrace_put_breakpoints(child);
 892                         break;
 893                 case PTRACE_SETHBPREGS:
 894                         if (ptrace_get_breakpoints(child) < 0)
 895                                 return -ESRCH;
 896
 897                         ret = ptrace_sethbpregs(child, addr,
 898                                                 (unsigned long __user *)data);
 899                         ptrace_put_breakpoints(child);
 900                         break;
 901 #endif
 902
 903                 default:
 904                         ret = ptrace_request(child, request, addr, data);
 905                         break;
 906         }
 907
 908         return ret;
 909 }
 910
 911 asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
 912 {
 913         unsigned long ip;
 914
 915         if (why)
 916                 audit_syscall_exit(regs);
 917         else
 918                 audit_syscall_entry(AUDIT_ARCH_ARM, scno, regs->ARM_r0,
 919                                     regs->ARM_r1, regs->ARM_r2, regs->ARM_r3);
 920
 921         if (why == 0 && test_and_clear_thread_flag(TIF_SYSCALL_RESTARTSYS))
 922                 scno = __NR_restart_syscall - __NR_SYSCALL_BASE;
 923         if (!test_thread_flag(TIF_SYSCALL_TRACE))
 924                 return scno;
 925
 926         current_thread_info()->syscall = scno;
 927
 928         /*
 929          * IP is used to denote syscall entry/exit:
 930          * IP = 0 -> entry, =1 -> exit
 931          */
 932         ip = regs->ARM_ip;
 933         regs->ARM_ip = why;
 934
 935         if (why)
 936                 tracehook_report_syscall_exit(regs, 0);
 937         else if (tracehook_report_syscall_entry(regs))
 938                 current_thread_info()->syscall = -1;
 939
 940         regs->ARM_ip = ip;
 941
 942         return current_thread_info()->syscall;
 943 }