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
  28 #include <asm/pgtable.h>
  29 #include <asm/system.h>
  30 #include <asm/traps.h>
  31
  32 #define REG_PC  15
  33 #define REG_PSR 16
  34 /*
  35  * does not yet catch signals sent when the child dies.
  36  * in exit.c or in signal.c.
  37  */
  38
  39 #if 0
  40 /*
  41  * Breakpoint SWI instruction: SWI &9F0001
  42  */
  43 #define BREAKINST_ARM   0xef9f0001
  44 #define BREAKINST_THUMB 0xdf00          /* fill this in later */
  45 #else
  46 /*
  47  * New breakpoints - use an undefined instruction.  The ARM architecture
  48  * reference manual guarantees that the following instruction space
  49  * will produce an undefined instruction exception on all CPUs:
  50  *
  51  *  ARM:   xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx
  52  *  Thumb: 1101 1110 xxxx xxxx
  53  */
  54 #define BREAKINST_ARM   0xe7f001f0
  55 #define BREAKINST_THUMB 0xde01
  56 #endif
  57
  58 struct pt_regs_offset {
  59         const char *name;
  60         int offset;
  61 };
  62
  63 #define REG_OFFSET_NAME(r) \
  64         {.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)}
  65 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  66
  67 static const struct pt_regs_offset regoffset_table[] = {
  68         REG_OFFSET_NAME(r0),
  69         REG_OFFSET_NAME(r1),
  70         REG_OFFSET_NAME(r2),
  71         REG_OFFSET_NAME(r3),
  72         REG_OFFSET_NAME(r4),
  73         REG_OFFSET_NAME(r5),
  74         REG_OFFSET_NAME(r6),
  75         REG_OFFSET_NAME(r7),
  76         REG_OFFSET_NAME(r8),
  77         REG_OFFSET_NAME(r9),
  78         REG_OFFSET_NAME(r10),
  79         REG_OFFSET_NAME(fp),
  80         REG_OFFSET_NAME(ip),
  81         REG_OFFSET_NAME(sp),
  82         REG_OFFSET_NAME(lr),
  83         REG_OFFSET_NAME(pc),
  84         REG_OFFSET_NAME(cpsr),
  85         REG_OFFSET_NAME(ORIG_r0),
  86         REG_OFFSET_END,
  87 };
  88
  89 /**
  90  * regs_query_register_offset() - query register offset from its name
  91  * @name:       the name of a register
  92  *
  93  * regs_query_register_offset() returns the offset of a register in struct
  94  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
  95  */
  96 int regs_query_register_offset(const char *name)
  97 {
  98         const struct pt_regs_offset *roff;
  99         for (roff = regoffset_table; roff->name != NULL; roff++)
 100                 if (!strcmp(roff->name, name))
 101                         return roff->offset;
 102         return -EINVAL;
 103 }
 104
 105 /**
 106  * regs_query_register_name() - query register name from its offset
 107  * @offset:     the offset of a register in struct pt_regs.
 108  *
 109  * regs_query_register_name() returns the name of a register from its
 110  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 111  */
 112 const char *regs_query_register_name(unsigned int offset)
 113 {
 114         const struct pt_regs_offset *roff;
 115         for (roff = regoffset_table; roff->name != NULL; roff++)
 116                 if (roff->offset == offset)
 117                         return roff->name;
 118         return NULL;
 119 }
 120
 121 /**
 122  * regs_within_kernel_stack() - check the address in the stack
 123  * @regs:      pt_regs which contains kernel stack pointer.
 124  * @addr:      address which is checked.
 125  *
 126  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 127  * If @addr is within the kernel stack, it returns true. If not, returns false.
 128  */
 129 bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 130 {
 131         return ((addr & ~(THREAD_SIZE - 1))  ==
 132                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
 133 }
 134
 135 /**
 136  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 137  * @regs:       pt_regs which contains kernel stack pointer.
 138  * @n:          stack entry number.
 139  *
 140  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 141  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 142  * this returns 0.
 143  */
 144 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 145 {
 146         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 147         addr += n;
 148         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 149                 return *addr;
 150         else
 151                 return 0;
 152 }
 153
 154 /*
 155  * this routine will get a word off of the processes privileged stack.
 156  * the offset is how far from the base addr as stored in the THREAD.
 157  * this routine assumes that all the privileged stacks are in our
 158  * data space.
 159  */
 160 static inline long get_user_reg(struct task_struct *task, int offset)
 161 {
 162         return task_pt_regs(task)->uregs[offset];
 163 }
 164
 165 /*
 166  * this routine will put a word on the processes privileged stack.
 167  * the offset is how far from the base addr as stored in the THREAD.
 168  * this routine assumes that all the privileged stacks are in our
 169  * data space.
 170  */
 171 static inline int
 172 put_user_reg(struct task_struct *task, int offset, long data)
 173 {
 174         struct pt_regs newregs, *regs = task_pt_regs(task);
 175         int ret = -EINVAL;
 176
 177         newregs = *regs;
 178         newregs.uregs[offset] = data;
 179
 180         if (valid_user_regs(&newregs)) {
 181                 regs->uregs[offset] = data;
 182                 ret = 0;
 183         }
 184
 185         return ret;
 186 }
 187
 188 /*
 189  * Called by kernel/ptrace.c when detaching..
 190  */
 191 void ptrace_disable(struct task_struct *child)
 192 {
 193         /* Nothing to do. */
 194 }
 195
 196 /*
 197  * Handle hitting a breakpoint.
 198  */
 199 void ptrace_break(struct task_struct *tsk, struct pt_regs *regs)
 200 {
 201         siginfo_t info;
 202
 203         info.si_signo = SIGTRAP;
 204         info.si_errno = 0;
 205         info.si_code  = TRAP_BRKPT;
 206         info.si_addr  = (void __user *)instruction_pointer(regs);
 207
 208         force_sig_info(SIGTRAP, &info, tsk);
 209 }
 210
 211 static int break_trap(struct pt_regs *regs, unsigned int instr)
 212 {
 213         ptrace_break(current, regs);
 214         return 0;
 215 }
 216
 217 static struct undef_hook arm_break_hook = {
 218         .instr_mask     = 0x0fffffff,
 219         .instr_val      = 0x07f001f0,
 220         .cpsr_mask      = PSR_T_BIT,
 221         .cpsr_val       = 0,
 222         .fn             = break_trap,
 223 };
 224
 225 static struct undef_hook thumb_break_hook = {
 226         .instr_mask     = 0xffff,
 227         .instr_val      = 0xde01,
 228         .cpsr_mask      = PSR_T_BIT,
 229         .cpsr_val       = PSR_T_BIT,
 230         .fn             = break_trap,
 231 };
 232
 233 static struct undef_hook thumb2_break_hook = {
 234         .instr_mask     = 0xffffffff,
 235         .instr_val      = 0xf7f0a000,
 236         .cpsr_mask      = PSR_T_BIT,
 237         .cpsr_val       = PSR_T_BIT,
 238         .fn             = break_trap,
 239 };
 240
 241 static int __init ptrace_break_init(void)
 242 {
 243         register_undef_hook(&arm_break_hook);
 244         register_undef_hook(&thumb_break_hook);
 245         register_undef_hook(&thumb2_break_hook);
 246         return 0;
 247 }
 248
 249 core_initcall(ptrace_break_init);
 250
 251 /*
 252  * Read the word at offset "off" into the "struct user".  We
 253  * actually access the pt_regs stored on the kernel stack.
 254  */
 255 static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
 256                             unsigned long __user *ret)
 257 {
 258         unsigned long tmp;
 259
 260         if (off & 3 || off >= sizeof(struct user))
 261                 return -EIO;
 262
 263         tmp = 0;
 264         if (off == PT_TEXT_ADDR)
 265                 tmp = tsk->mm->start_code;
 266         else if (off == PT_DATA_ADDR)
 267                 tmp = tsk->mm->start_data;
 268         else if (off == PT_TEXT_END_ADDR)
 269                 tmp = tsk->mm->end_code;
 270         else if (off < sizeof(struct pt_regs))
 271                 tmp = get_user_reg(tsk, off >> 2);
 272
 273         return put_user(tmp, ret);
 274 }
 275
 276 /*
 277  * Write the word at offset "off" into "struct user".  We
 278  * actually access the pt_regs stored on the kernel stack.
 279  */
 280 static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
 281                              unsigned long val)
 282 {
 283         if (off & 3 || off >= sizeof(struct user))
 284                 return -EIO;
 285
 286         if (off >= sizeof(struct pt_regs))
 287                 return 0;
 288
 289         return put_user_reg(tsk, off >> 2, val);
 290 }
 291
 292 #ifdef CONFIG_IWMMXT
 293
 294 /*
 295  * Get the child iWMMXt state.
 296  */
 297 static int ptrace_getwmmxregs(struct task_struct *tsk, void __user *ufp)
 298 {
 299         struct thread_info *thread = task_thread_info(tsk);
 300
 301         if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
 302                 return -ENODATA;
 303         iwmmxt_task_disable(thread);  /* force it to ram */
 304         return copy_to_user(ufp, &thread->fpstate.iwmmxt, IWMMXT_SIZE)
 305                 ? -EFAULT : 0;
 306 }
 307
 308 /*
 309  * Set the child iWMMXt state.
 310  */
 311 static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp)
 312 {
 313         struct thread_info *thread = task_thread_info(tsk);
 314
 315         if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
 316                 return -EACCES;
 317         iwmmxt_task_release(thread);  /* force a reload */
 318         return copy_from_user(&thread->fpstate.iwmmxt, ufp, IWMMXT_SIZE)
 319                 ? -EFAULT : 0;
 320 }
 321
 322 #endif
 323
 324 #ifdef CONFIG_CRUNCH
 325 /*
 326  * Get the child Crunch state.
 327  */
 328 static int ptrace_getcrunchregs(struct task_struct *tsk, void __user *ufp)
 329 {
 330         struct thread_info *thread = task_thread_info(tsk);
 331
 332         crunch_task_disable(thread);  /* force it to ram */
 333         return copy_to_user(ufp, &thread->crunchstate, CRUNCH_SIZE)
 334                 ? -EFAULT : 0;
 335 }
 336
 337 /*
 338  * Set the child Crunch state.
 339  */
 340 static int ptrace_setcrunchregs(struct task_struct *tsk, void __user *ufp)
 341 {
 342         struct thread_info *thread = task_thread_info(tsk);
 343
 344         crunch_task_release(thread);  /* force a reload */
 345         return copy_from_user(&thread->crunchstate, ufp, CRUNCH_SIZE)
 346                 ? -EFAULT : 0;
 347 }
 348 #endif
 349
 350 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 351 /*
 352  * Convert a virtual register number into an index for a thread_info
 353  * breakpoint array. Breakpoints are identified using positive numbers
 354  * whilst watchpoints are negative. The registers are laid out as pairs
 355  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
 356  * Register 0 is reserved for describing resource information.
 357  */
 358 static int ptrace_hbp_num_to_idx(long num)
 359 {
 360         if (num < 0)
 361                 num = (ARM_MAX_BRP << 1) - num;
 362         return (num - 1) >> 1;
 363 }
 364
 365 /*
 366  * Returns the virtual register number for the address of the
 367  * breakpoint at index idx.
 368  */
 369 static long ptrace_hbp_idx_to_num(int idx)
 370 {
 371         long mid = ARM_MAX_BRP << 1;
 372         long num = (idx << 1) + 1;
 373         return num > mid ? mid - num : num;
 374 }
 375
 376 /*
 377  * Handle hitting a HW-breakpoint.
 378  */
 379 static void ptrace_hbptriggered(struct perf_event *bp,
 380                                      struct perf_sample_data *data,
 381                                      struct pt_regs *regs)
 382 {
 383         struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
 384         long num;
 385         int i;
 386         siginfo_t info;
 387
 388         for (i = 0; i < ARM_MAX_HBP_SLOTS; ++i)
 389                 if (current->thread.debug.hbp[i] == bp)
 390                         break;
 391
 392         num = (i == ARM_MAX_HBP_SLOTS) ? 0 : ptrace_hbp_idx_to_num(i);
 393
 394         info.si_signo   = SIGTRAP;
 395         info.si_errno   = (int)num;
 396         info.si_code    = TRAP_HWBKPT;
 397         info.si_addr    = (void __user *)(bkpt->trigger);
 398
 399         force_sig_info(SIGTRAP, &info, current);
 400 }
 401
 402 /*
 403  * Set ptrace breakpoint pointers to zero for this task.
 404  * This is required in order to prevent child processes from unregistering
 405  * breakpoints held by their parent.
 406  */
 407 void clear_ptrace_hw_breakpoint(struct task_struct *tsk)
 408 {
 409         memset(tsk->thread.debug.hbp, 0, sizeof(tsk->thread.debug.hbp));
 410 }
 411
 412 /*
 413  * Unregister breakpoints from this task and reset the pointers in
 414  * the thread_struct.
 415  */
 416 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 417 {
 418         int i;
 419         struct thread_struct *t = &tsk->thread;
 420
 421         for (i = 0; i < ARM_MAX_HBP_SLOTS; i++) {
 422                 if (t->debug.hbp[i]) {
 423                         unregister_hw_breakpoint(t->debug.hbp[i]);
 424                         t->debug.hbp[i] = NULL;
 425                 }
 426         }
 427 }
 428
 429 static u32 ptrace_get_hbp_resource_info(void)
 430 {
 431         u8 num_brps, num_wrps, debug_arch, wp_len;
 432         u32 reg = 0;
 433
 434         num_brps        = hw_breakpoint_slots(TYPE_INST);
 435         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
 436         debug_arch      = arch_get_debug_arch();
 437         wp_len          = arch_get_max_wp_len();
 438
 439         reg             |= debug_arch;
 440         reg             <<= 8;
 441         reg             |= wp_len;
 442         reg             <<= 8;
 443         reg             |= num_wrps;
 444         reg             <<= 8;
 445         reg             |= num_brps;
 446
 447         return reg;
 448 }
 449
 450 static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
 451 {
 452         struct perf_event_attr attr;
 453
 454         ptrace_breakpoint_init(&attr);
 455
 456         /* Initialise fields to sane defaults. */
 457         attr.bp_addr    = 0;
 458         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 459         attr.bp_type    = type;
 460         attr.disabled   = 1;
 461
 462         return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL,
 463                                            tsk);
 464 }
 465
 466 static int ptrace_gethbpregs(struct task_struct *tsk, long num,
 467                              unsigned long  __user *data)
 468 {
 469         u32 reg;
 470         int idx, ret = 0;
 471         struct perf_event *bp;
 472         struct arch_hw_breakpoint_ctrl arch_ctrl;
 473
 474         if (num == 0) {
 475                 reg = ptrace_get_hbp_resource_info();
 476         } else {
 477                 idx = ptrace_hbp_num_to_idx(num);
 478                 if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
 479                         ret = -EINVAL;
 480                         goto out;
 481                 }
 482
 483                 bp = tsk->thread.debug.hbp[idx];
 484                 if (!bp) {
 485                         reg = 0;
 486                         goto put;
 487                 }
 488
 489                 arch_ctrl = counter_arch_bp(bp)->ctrl;
 490
 491                 /*
 492                  * Fix up the len because we may have adjusted it
 493                  * to compensate for an unaligned address.
 494                  */
 495                 while (!(arch_ctrl.len & 0x1))
 496                         arch_ctrl.len >>= 1;
 497
 498                 if (num & 0x1)
 499                         reg = bp->attr.bp_addr;
 500                 else
 501                         reg = encode_ctrl_reg(arch_ctrl);
 502         }
 503
 504 put:
 505         if (put_user(reg, data))
 506                 ret = -EFAULT;
 507
 508 out:
 509         return ret;
 510 }
 511
 512 static int ptrace_sethbpregs(struct task_struct *tsk, long num,
 513                              unsigned long __user *data)
 514 {
 515         int idx, gen_len, gen_type, implied_type, ret = 0;
 516         u32 user_val;
 517         struct perf_event *bp;
 518         struct arch_hw_breakpoint_ctrl ctrl;
 519         struct perf_event_attr attr;
 520
 521         if (num == 0)
 522                 goto out;
 523         else if (num < 0)
 524                 implied_type = HW_BREAKPOINT_RW;
 525         else
 526                 implied_type = HW_BREAKPOINT_X;
 527
 528         idx = ptrace_hbp_num_to_idx(num);
 529         if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
 530                 ret = -EINVAL;
 531                 goto out;
 532         }
 533
 534         if (get_user(user_val, data)) {
 535                 ret = -EFAULT;
 536                 goto out;
 537         }
 538
 539         bp = tsk->thread.debug.hbp[idx];
 540         if (!bp) {
 541                 bp = ptrace_hbp_create(tsk, implied_type);
 542                 if (IS_ERR(bp)) {
 543                         ret = PTR_ERR(bp);
 544                         goto out;
 545                 }
 546                 tsk->thread.debug.hbp[idx] = bp;
 547         }
 548
 549         attr = bp->attr;
 550
 551         if (num & 0x1) {
 552                 /* Address */
 553                 attr.bp_addr    = user_val;
 554         } else {
 555                 /* Control */
 556                 decode_ctrl_reg(user_val, &ctrl);
 557                 ret = arch_bp_generic_fields(ctrl, &gen_len, &gen_type);
 558                 if (ret)
 559                         goto out;
 560
 561                 if ((gen_type & implied_type) != gen_type) {
 562                         ret = -EINVAL;
 563                         goto out;
 564                 }
 565
 566                 attr.bp_len     = gen_len;
 567                 attr.bp_type    = gen_type;
 568                 attr.disabled   = !ctrl.enabled;
 569         }
 570
 571         ret = modify_user_hw_breakpoint(bp, &attr);
 572 out:
 573         return ret;
 574 }
 575 #endif
 576
 577 /* regset get/set implementations */
 578
 579 static int gpr_get(struct task_struct *target,
 580                    const struct user_regset *regset,
 581                    unsigned int pos, unsigned int count,
 582                    void *kbuf, void __user *ubuf)
 583 {
 584         struct pt_regs *regs = task_pt_regs(target);
 585
 586         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 587                                    regs,
 588                                    0, sizeof(*regs));
 589 }
 590
 591 static int gpr_set(struct task_struct *target,
 592                    const struct user_regset *regset,
 593                    unsigned int pos, unsigned int count,
 594                    const void *kbuf, const void __user *ubuf)
 595 {
 596         int ret;
 597         struct pt_regs newregs;
 598
 599         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 600                                  &newregs,
 601                                  0, sizeof(newregs));
 602         if (ret)
 603                 return ret;
 604
 605         if (!valid_user_regs(&newregs))
 606                 return -EINVAL;
 607
 608         *task_pt_regs(target) = newregs;
 609         return 0;
 610 }
 611
 612 static int fpa_get(struct task_struct *target,
 613                    const struct user_regset *regset,
 614                    unsigned int pos, unsigned int count,
 615                    void *kbuf, void __user *ubuf)
 616 {
 617         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 618                                    &task_thread_info(target)->fpstate,
 619                                    0, sizeof(struct user_fp));
 620 }
 621
 622 static int fpa_set(struct task_struct *target,
 623                    const struct user_regset *regset,
 624                    unsigned int pos, unsigned int count,
 625                    const void *kbuf, const void __user *ubuf)
 626 {
 627         struct thread_info *thread = task_thread_info(target);
 628
 629         thread->used_cp[1] = thread->used_cp[2] = 1;
 630
 631         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 632                 &thread->fpstate,
 633                 0, sizeof(struct user_fp));
 634 }
 635
 636 #ifdef CONFIG_VFP
 637 /*
 638  * VFP register get/set implementations.
 639  *
 640  * With respect to the kernel, struct user_fp is divided into three chunks:
 641  * 16 or 32 real VFP registers (d0-d15 or d0-31)
 642  *      These are transferred to/from the real registers in the task's
 643  *      vfp_hard_struct.  The number of registers depends on the kernel
 644  *      configuration.
 645  *
 646  * 16 or 0 fake VFP registers (d16-d31 or empty)
 647  *      i.e., the user_vfp structure has space for 32 registers even if
 648  *      the kernel doesn't have them all.
 649  *
 650  *      vfp_get() reads this chunk as zero where applicable
 651  *      vfp_set() ignores this chunk
 652  *
 653  * 1 word for the FPSCR
 654  *
 655  * The bounds-checking logic built into user_regset_copyout and friends
 656  * means that we can make a simple sequence of calls to map the relevant data
 657  * to/from the specified slice of the user regset structure.
 658  */
 659 static int vfp_get(struct task_struct *target,
 660                    const struct user_regset *regset,
 661                    unsigned int pos, unsigned int count,
 662                    void *kbuf, void __user *ubuf)
 663 {
 664         int ret;
 665         struct thread_info *thread = task_thread_info(target);
 666         struct vfp_hard_struct const *vfp = &thread->vfpstate.hard;
 667         const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
 668         const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
 669
 670         vfp_sync_hwstate(thread);
 671
 672         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 673                                   &vfp->fpregs,
 674                                   user_fpregs_offset,
 675                                   user_fpregs_offset + sizeof(vfp->fpregs));
 676         if (ret)
 677                 return ret;
 678
 679         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 680                                        user_fpregs_offset + sizeof(vfp->fpregs),
 681                                        user_fpscr_offset);
 682         if (ret)
 683                 return ret;
 684
 685         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 686                                    &vfp->fpscr,
 687                                    user_fpscr_offset,
 688                                    user_fpscr_offset + sizeof(vfp->fpscr));
 689 }
 690
 691 /*
 692  * For vfp_set() a read-modify-write is done on the VFP registers,
 693  * in order to avoid writing back a half-modified set of registers on
 694  * failure.
 695  */
 696 static int vfp_set(struct task_struct *target,
 697                           const struct user_regset *regset,
 698                           unsigned int pos, unsigned int count,
 699                           const void *kbuf, const void __user *ubuf)
 700 {
 701         int ret;
 702         struct thread_info *thread = task_thread_info(target);
 703         struct vfp_hard_struct new_vfp;
 704         const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
 705         const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
 706
 707         vfp_sync_hwstate(thread);
 708         new_vfp = thread->vfpstate.hard;
 709
 710         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 711                                   &new_vfp.fpregs,
 712                                   user_fpregs_offset,
 713                                   user_fpregs_offset + sizeof(new_vfp.fpregs));
 714         if (ret)
 715                 return ret;
 716
 717         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 718                                 user_fpregs_offset + sizeof(new_vfp.fpregs),
 719                                 user_fpscr_offset);
 720         if (ret)
 721                 return ret;
 722
 723         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 724                                  &new_vfp.fpscr,
 725                                  user_fpscr_offset,
 726                                  user_fpscr_offset + sizeof(new_vfp.fpscr));
 727         if (ret)
 728                 return ret;
 729
 730         vfp_flush_hwstate(thread);
 731         thread->vfpstate.hard = new_vfp;
 732
 733         return 0;
 734 }
 735 #endif /* CONFIG_VFP */
 736
 737 enum arm_regset {
 738         REGSET_GPR,
 739         REGSET_FPR,
 740 #ifdef CONFIG_VFP
 741         REGSET_VFP,
 742 #endif
 743 };
 744
 745 static const struct user_regset arm_regsets[] = {
 746         [REGSET_GPR] = {
 747                 .core_note_type = NT_PRSTATUS,
 748                 .n = ELF_NGREG,
 749                 .size = sizeof(u32),
 750                 .align = sizeof(u32),
 751                 .get = gpr_get,
 752                 .set = gpr_set
 753         },
 754         [REGSET_FPR] = {
 755                 /*
 756                  * For the FPA regs in fpstate, the real fields are a mixture
 757                  * of sizes, so pretend that the registers are word-sized:
 758                  */
 759                 .core_note_type = NT_PRFPREG,
 760                 .n = sizeof(struct user_fp) / sizeof(u32),
 761                 .size = sizeof(u32),
 762                 .align = sizeof(u32),
 763                 .get = fpa_get,
 764                 .set = fpa_set
 765         },
 766 #ifdef CONFIG_VFP
 767         [REGSET_VFP] = {
 768                 /*
 769                  * Pretend that the VFP regs are word-sized, since the FPSCR is
 770                  * a single word dangling at the end of struct user_vfp:
 771                  */
 772                 .core_note_type = NT_ARM_VFP,
 773                 .n = ARM_VFPREGS_SIZE / sizeof(u32),
 774                 .size = sizeof(u32),
 775                 .align = sizeof(u32),
 776                 .get = vfp_get,
 777                 .set = vfp_set
 778         },
 779 #endif /* CONFIG_VFP */
 780 };
 781
 782 static const struct user_regset_view user_arm_view = {
 783         .name = "arm", .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI,
 784         .regsets = arm_regsets, .n = ARRAY_SIZE(arm_regsets)
 785 };
 786
 787 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 788 {
 789         return &user_arm_view;
 790 }
 791
 792 long arch_ptrace(struct task_struct *child, long request,
 793                  unsigned long addr, unsigned long data)
 794 {
 795         int ret;
 796         unsigned long __user *datap = (unsigned long __user *) data;
 797
 798         switch (request) {
 799                 case PTRACE_PEEKUSR:
 800                         ret = ptrace_read_user(child, addr, datap);
 801                         break;
 802
 803                 case PTRACE_POKEUSR:
 804                         ret = ptrace_write_user(child, addr, data);
 805                         break;
 806
 807                 case PTRACE_GETREGS:
 808                         ret = copy_regset_to_user(child,
 809                                                   &user_arm_view, REGSET_GPR,
 810                                                   0, sizeof(struct pt_regs),
 811                                                   datap);
 812                         break;
 813
 814                 case PTRACE_SETREGS:
 815                         ret = copy_regset_from_user(child,
 816                                                     &user_arm_view, REGSET_GPR,
 817                                                     0, sizeof(struct pt_regs),
 818                                                     datap);
 819                         break;
 820
 821                 case PTRACE_GETFPREGS:
 822                         ret = copy_regset_to_user(child,
 823                                                   &user_arm_view, REGSET_FPR,
 824                                                   0, sizeof(union fp_state),
 825                                                   datap);
 826                         break;
 827
 828                 case PTRACE_SETFPREGS:
 829                         ret = copy_regset_from_user(child,
 830                                                     &user_arm_view, REGSET_FPR,
 831                                                     0, sizeof(union fp_state),
 832                                                     datap);
 833                         break;
 834
 835 #ifdef CONFIG_IWMMXT
 836                 case PTRACE_GETWMMXREGS:
 837                         ret = ptrace_getwmmxregs(child, datap);
 838                         break;
 839
 840                 case PTRACE_SETWMMXREGS:
 841                         ret = ptrace_setwmmxregs(child, datap);
 842                         break;
 843 #endif
 844
 845                 case PTRACE_GET_THREAD_AREA:
 846                         ret = put_user(task_thread_info(child)->tp_value,
 847                                        datap);
 848                         break;
 849
 850                 case PTRACE_SET_SYSCALL:
 851                         task_thread_info(child)->syscall = data;
 852                         ret = 0;
 853                         break;
 854
 855 #ifdef CONFIG_CRUNCH
 856                 case PTRACE_GETCRUNCHREGS:
 857                         ret = ptrace_getcrunchregs(child, datap);
 858                         break;
 859
 860                 case PTRACE_SETCRUNCHREGS:
 861                         ret = ptrace_setcrunchregs(child, datap);
 862                         break;
 863 #endif
 864
 865 #ifdef CONFIG_VFP
 866                 case PTRACE_GETVFPREGS:
 867                         ret = copy_regset_to_user(child,
 868                                                   &user_arm_view, REGSET_VFP,
 869                                                   0, ARM_VFPREGS_SIZE,
 870                                                   datap);
 871                         break;
 872
 873                 case PTRACE_SETVFPREGS:
 874                         ret = copy_regset_from_user(child,
 875                                                     &user_arm_view, REGSET_VFP,
 876                                                     0, ARM_VFPREGS_SIZE,
 877                                                     datap);
 878                         break;
 879 #endif
 880
 881 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 882                 case PTRACE_GETHBPREGS:
 883                         if (ptrace_get_breakpoints(child) < 0)
 884                                 return -ESRCH;
 885
 886                         ret = ptrace_gethbpregs(child, addr,
 887                                                 (unsigned long __user *)data);
 888                         ptrace_put_breakpoints(child);
 889                         break;
 890                 case PTRACE_SETHBPREGS:
 891                         if (ptrace_get_breakpoints(child) < 0)
 892                                 return -ESRCH;
 893
 894                         ret = ptrace_sethbpregs(child, addr,
 895                                                 (unsigned long __user *)data);
 896                         ptrace_put_breakpoints(child);
 897                         break;
 898 #endif
 899
 900                 default:
 901                         ret = ptrace_request(child, request, addr, data);
 902                         break;
 903         }
 904
 905         return ret;
 906 }
 907
 908 #ifdef __ARMEB__
 909 #define AUDIT_ARCH_NR AUDIT_ARCH_ARMEB
 910 #else
 911 #define AUDIT_ARCH_NR AUDIT_ARCH_ARM
 912 #endif
 913
 914 asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
 915 {
 916         unsigned long ip;
 917
 918         /*
 919          * Save IP.  IP is used to denote syscall entry/exit:
 920          *  IP = 0 -> entry, = 1 -> exit
 921          */
 922         ip = regs->ARM_ip;
 923         regs->ARM_ip = why;
 924
 925         if (!ip)
 926                 audit_syscall_exit(regs);
 927         else
 928                 audit_syscall_entry(AUDIT_ARCH_NR, scno, regs->ARM_r0,
 929                                     regs->ARM_r1, regs->ARM_r2, regs->ARM_r3);
 930
 931         if (!test_thread_flag(TIF_SYSCALL_TRACE))
 932                 return scno;
 933         if (!(current->ptrace & PT_PTRACED))
 934                 return scno;
 935
 936         current_thread_info()->syscall = scno;
 937
 938         /* the 0x80 provides a way for the tracing parent to distinguish
 939            between a syscall stop and SIGTRAP delivery */
 940         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 941                                  ? 0x80 : 0));
 942         /*
 943          * this isn't the same as continuing with a signal, but it will do
 944          * for normal use.  strace only continues with a signal if the
 945          * stopping signal is not SIGTRAP.  -brl
 946          */
 947         if (current->exit_code) {
 948                 send_sig(current->exit_code, current, 1);
 949                 current->exit_code = 0;
 950         }
 951         regs->ARM_ip = ip;
 952
 953         return current_thread_info()->syscall;
 954 }