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/smp.h>
  16 #include <linux/ptrace.h>
  17 #include <linux/user.h>
  18 #include <linux/security.h>
  19 #include <linux/init.h>
  20 #include <linux/signal.h>
  21 #include <linux/uaccess.h>
  22 #include <linux/perf_event.h>
  23 #include <linux/hw_breakpoint.h>
  24 #include <linux/regset.h>
  25
  26 #include <asm/pgtable.h>
  27 #include <asm/system.h>
  28 #include <asm/traps.h>
  29
  30 #define REG_PC  15
  31 #define REG_PSR 16
  32 /*
  33  * does not yet catch signals sent when the child dies.
  34  * in exit.c or in signal.c.
  35  */
  36
  37 #if 0
  38 /*
  39  * Breakpoint SWI instruction: SWI &9F0001
  40  */
  41 #define BREAKINST_ARM   0xef9f0001
  42 #define BREAKINST_THUMB 0xdf00          /* fill this in later */
  43 #else
  44 /*
  45  * New breakpoints - use an undefined instruction.  The ARM architecture
  46  * reference manual guarantees that the following instruction space
  47  * will produce an undefined instruction exception on all CPUs:
  48  *
  49  *  ARM:   xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx
  50  *  Thumb: 1101 1110 xxxx xxxx
  51  */
  52 #define BREAKINST_ARM   0xe7f001f0
  53 #define BREAKINST_THUMB 0xde01
  54 #endif
  55
  56 struct pt_regs_offset {
  57         const char *name;
  58         int offset;
  59 };
  60
  61 #define REG_OFFSET_NAME(r) \
  62         {.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)}
  63 #define REG_OFFSET_END {.name = NULL, .offset = 0}
  64
  65 static const struct pt_regs_offset regoffset_table[] = {
  66         REG_OFFSET_NAME(r0),
  67         REG_OFFSET_NAME(r1),
  68         REG_OFFSET_NAME(r2),
  69         REG_OFFSET_NAME(r3),
  70         REG_OFFSET_NAME(r4),
  71         REG_OFFSET_NAME(r5),
  72         REG_OFFSET_NAME(r6),
  73         REG_OFFSET_NAME(r7),
  74         REG_OFFSET_NAME(r8),
  75         REG_OFFSET_NAME(r9),
  76         REG_OFFSET_NAME(r10),
  77         REG_OFFSET_NAME(fp),
  78         REG_OFFSET_NAME(ip),
  79         REG_OFFSET_NAME(sp),
  80         REG_OFFSET_NAME(lr),
  81         REG_OFFSET_NAME(pc),
  82         REG_OFFSET_NAME(cpsr),
  83         REG_OFFSET_NAME(ORIG_r0),
  84         REG_OFFSET_END,
  85 };
  86
  87 /**
  88  * regs_query_register_offset() - query register offset from its name
  89  * @name:       the name of a register
  90  *
  91  * regs_query_register_offset() returns the offset of a register in struct
  92  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
  93  */
  94 int regs_query_register_offset(const char *name)
  95 {
  96         const struct pt_regs_offset *roff;
  97         for (roff = regoffset_table; roff->name != NULL; roff++)
  98                 if (!strcmp(roff->name, name))
  99                         return roff->offset;
 100         return -EINVAL;
 101 }
 102
 103 /**
 104  * regs_query_register_name() - query register name from its offset
 105  * @offset:     the offset of a register in struct pt_regs.
 106  *
 107  * regs_query_register_name() returns the name of a register from its
 108  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 109  */
 110 const char *regs_query_register_name(unsigned int offset)
 111 {
 112         const struct pt_regs_offset *roff;
 113         for (roff = regoffset_table; roff->name != NULL; roff++)
 114                 if (roff->offset == offset)
 115                         return roff->name;
 116         return NULL;
 117 }
 118
 119 /**
 120  * regs_within_kernel_stack() - check the address in the stack
 121  * @regs:      pt_regs which contains kernel stack pointer.
 122  * @addr:      address which is checked.
 123  *
 124  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 125  * If @addr is within the kernel stack, it returns true. If not, returns false.
 126  */
 127 bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 128 {
 129         return ((addr & ~(THREAD_SIZE - 1))  ==
 130                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
 131 }
 132
 133 /**
 134  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 135  * @regs:       pt_regs which contains kernel stack pointer.
 136  * @n:          stack entry number.
 137  *
 138  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 139  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 140  * this returns 0.
 141  */
 142 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 143 {
 144         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 145         addr += n;
 146         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 147                 return *addr;
 148         else
 149                 return 0;
 150 }
 151
 152 /*
 153  * this routine will get a word off of the processes privileged stack.
 154  * the offset is how far from the base addr as stored in the THREAD.
 155  * this routine assumes that all the privileged stacks are in our
 156  * data space.
 157  */
 158 static inline long get_user_reg(struct task_struct *task, int offset)
 159 {
 160         return task_pt_regs(task)->uregs[offset];
 161 }
 162
 163 /*
 164  * this routine will put a word on the processes privileged stack.
 165  * the offset is how far from the base addr as stored in the THREAD.
 166  * this routine assumes that all the privileged stacks are in our
 167  * data space.
 168  */
 169 static inline int
 170 put_user_reg(struct task_struct *task, int offset, long data)
 171 {
 172         struct pt_regs newregs, *regs = task_pt_regs(task);
 173         int ret = -EINVAL;
 174
 175         newregs = *regs;
 176         newregs.uregs[offset] = data;
 177
 178         if (valid_user_regs(&newregs)) {
 179                 regs->uregs[offset] = data;
 180                 ret = 0;
 181         }
 182
 183         return ret;
 184 }
 185
 186 /*
 187  * Called by kernel/ptrace.c when detaching..
 188  */
 189 void ptrace_disable(struct task_struct *child)
 190 {
 191         /* Nothing to do. */
 192 }
 193
 194 /*
 195  * Handle hitting a breakpoint.
 196  */
 197 void ptrace_break(struct task_struct *tsk, struct pt_regs *regs)
 198 {
 199         siginfo_t info;
 200
 201         info.si_signo = SIGTRAP;
 202         info.si_errno = 0;
 203         info.si_code  = TRAP_BRKPT;
 204         info.si_addr  = (void __user *)instruction_pointer(regs);
 205
 206         force_sig_info(SIGTRAP, &info, tsk);
 207 }
 208
 209 static int break_trap(struct pt_regs *regs, unsigned int instr)
 210 {
 211         ptrace_break(current, regs);
 212         return 0;
 213 }
 214
 215 static struct undef_hook arm_break_hook = {
 216         .instr_mask     = 0x0fffffff,
 217         .instr_val      = 0x07f001f0,
 218         .cpsr_mask      = PSR_T_BIT,
 219         .cpsr_val       = 0,
 220         .fn             = break_trap,
 221 };
 222
 223 static struct undef_hook thumb_break_hook = {
 224         .instr_mask     = 0xffff,
 225         .instr_val      = 0xde01,
 226         .cpsr_mask      = PSR_T_BIT,
 227         .cpsr_val       = PSR_T_BIT,
 228         .fn             = break_trap,
 229 };
 230
 231 static struct undef_hook thumb2_break_hook = {
 232         .instr_mask     = 0xffffffff,
 233         .instr_val      = 0xf7f0a000,
 234         .cpsr_mask      = PSR_T_BIT,
 235         .cpsr_val       = PSR_T_BIT,
 236         .fn             = break_trap,
 237 };
 238
 239 static int __init ptrace_break_init(void)
 240 {
 241         register_undef_hook(&arm_break_hook);
 242         register_undef_hook(&thumb_break_hook);
 243         register_undef_hook(&thumb2_break_hook);
 244         return 0;
 245 }
 246
 247 core_initcall(ptrace_break_init);
 248
 249 /*
 250  * Read the word at offset "off" into the "struct user".  We
 251  * actually access the pt_regs stored on the kernel stack.
 252  */
 253 static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
 254                             unsigned long __user *ret)
 255 {
 256         unsigned long tmp;
 257
 258         if (off & 3 || off >= sizeof(struct user))
 259                 return -EIO;
 260
 261         tmp = 0;
 262         if (off == PT_TEXT_ADDR)
 263                 tmp = tsk->mm->start_code;
 264         else if (off == PT_DATA_ADDR)
 265                 tmp = tsk->mm->start_data;
 266         else if (off == PT_TEXT_END_ADDR)
 267                 tmp = tsk->mm->end_code;
 268         else if (off < sizeof(struct pt_regs))
 269                 tmp = get_user_reg(tsk, off >> 2);
 270
 271         return put_user(tmp, ret);
 272 }
 273
 274 /*
 275  * Write the word at offset "off" into "struct user".  We
 276  * actually access the pt_regs stored on the kernel stack.
 277  */
 278 static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
 279                              unsigned long val)
 280 {
 281         if (off & 3 || off >= sizeof(struct user))
 282                 return -EIO;
 283
 284         if (off >= sizeof(struct pt_regs))
 285                 return 0;
 286
 287         return put_user_reg(tsk, off >> 2, val);
 288 }
 289
 290 #ifdef CONFIG_IWMMXT
 291
 292 /*
 293  * Get the child iWMMXt state.
 294  */
 295 static int ptrace_getwmmxregs(struct task_struct *tsk, void __user *ufp)
 296 {
 297         struct thread_info *thread = task_thread_info(tsk);
 298
 299         if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
 300                 return -ENODATA;
 301         iwmmxt_task_disable(thread);  /* force it to ram */
 302         return copy_to_user(ufp, &thread->fpstate.iwmmxt, IWMMXT_SIZE)
 303                 ? -EFAULT : 0;
 304 }
 305
 306 /*
 307  * Set the child iWMMXt state.
 308  */
 309 static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp)
 310 {
 311         struct thread_info *thread = task_thread_info(tsk);
 312
 313         if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
 314                 return -EACCES;
 315         iwmmxt_task_release(thread);  /* force a reload */
 316         return copy_from_user(&thread->fpstate.iwmmxt, ufp, IWMMXT_SIZE)
 317                 ? -EFAULT : 0;
 318 }
 319
 320 #endif
 321
 322 #ifdef CONFIG_CRUNCH
 323 /*
 324  * Get the child Crunch state.
 325  */
 326 static int ptrace_getcrunchregs(struct task_struct *tsk, void __user *ufp)
 327 {
 328         struct thread_info *thread = task_thread_info(tsk);
 329
 330         crunch_task_disable(thread);  /* force it to ram */
 331         return copy_to_user(ufp, &thread->crunchstate, CRUNCH_SIZE)
 332                 ? -EFAULT : 0;
 333 }
 334
 335 /*
 336  * Set the child Crunch state.
 337  */
 338 static int ptrace_setcrunchregs(struct task_struct *tsk, void __user *ufp)
 339 {
 340         struct thread_info *thread = task_thread_info(tsk);
 341
 342         crunch_task_release(thread);  /* force a reload */
 343         return copy_from_user(&thread->crunchstate, ufp, CRUNCH_SIZE)
 344                 ? -EFAULT : 0;
 345 }
 346 #endif
 347
 348 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 349 /*
 350  * Convert a virtual register number into an index for a thread_info
 351  * breakpoint array. Breakpoints are identified using positive numbers
 352  * whilst watchpoints are negative. The registers are laid out as pairs
 353  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
 354  * Register 0 is reserved for describing resource information.
 355  */
 356 static int ptrace_hbp_num_to_idx(long num)
 357 {
 358         if (num < 0)
 359                 num = (ARM_MAX_BRP << 1) - num;
 360         return (num - 1) >> 1;
 361 }
 362
 363 /*
 364  * Returns the virtual register number for the address of the
 365  * breakpoint at index idx.
 366  */
 367 static long ptrace_hbp_idx_to_num(int idx)
 368 {
 369         long mid = ARM_MAX_BRP << 1;
 370         long num = (idx << 1) + 1;
 371         return num > mid ? mid - num : num;
 372 }
 373
 374 /*
 375  * Handle hitting a HW-breakpoint.
 376  */
 377 static void ptrace_hbptriggered(struct perf_event *bp,
 378                                      struct perf_sample_data *data,
 379                                      struct pt_regs *regs)
 380 {
 381         struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
 382         long num;
 383         int i;
 384         siginfo_t info;
 385
 386         for (i = 0; i < ARM_MAX_HBP_SLOTS; ++i)
 387                 if (current->thread.debug.hbp[i] == bp)
 388                         break;
 389
 390         num = (i == ARM_MAX_HBP_SLOTS) ? 0 : ptrace_hbp_idx_to_num(i);
 391
 392         info.si_signo   = SIGTRAP;
 393         info.si_errno   = (int)num;
 394         info.si_code    = TRAP_HWBKPT;
 395         info.si_addr    = (void __user *)(bkpt->trigger);
 396
 397         force_sig_info(SIGTRAP, &info, current);
 398 }
 399
 400 /*
 401  * Set ptrace breakpoint pointers to zero for this task.
 402  * This is required in order to prevent child processes from unregistering
 403  * breakpoints held by their parent.
 404  */
 405 void clear_ptrace_hw_breakpoint(struct task_struct *tsk)
 406 {
 407         memset(tsk->thread.debug.hbp, 0, sizeof(tsk->thread.debug.hbp));
 408 }
 409
 410 /*
 411  * Unregister breakpoints from this task and reset the pointers in
 412  * the thread_struct.
 413  */
 414 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 415 {
 416         int i;
 417         struct thread_struct *t = &tsk->thread;
 418
 419         for (i = 0; i < ARM_MAX_HBP_SLOTS; i++) {
 420                 if (t->debug.hbp[i]) {
 421                         unregister_hw_breakpoint(t->debug.hbp[i]);
 422                         t->debug.hbp[i] = NULL;
 423                 }
 424         }
 425 }
 426
 427 static u32 ptrace_get_hbp_resource_info(void)
 428 {
 429         u8 num_brps, num_wrps, debug_arch, wp_len;
 430         u32 reg = 0;
 431
 432         num_brps        = hw_breakpoint_slots(TYPE_INST);
 433         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
 434         debug_arch      = arch_get_debug_arch();
 435         wp_len          = arch_get_max_wp_len();
 436
 437         reg             |= debug_arch;
 438         reg             <<= 8;
 439         reg             |= wp_len;
 440         reg             <<= 8;
 441         reg             |= num_wrps;
 442         reg             <<= 8;
 443         reg             |= num_brps;
 444
 445         return reg;
 446 }
 447
 448 static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
 449 {
 450         struct perf_event_attr attr;
 451
 452         ptrace_breakpoint_init(&attr);
 453
 454         /* Initialise fields to sane defaults. */
 455         attr.bp_addr    = 0;
 456         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 457         attr.bp_type    = type;
 458         attr.disabled   = 1;
 459
 460         return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL,
 461                                            tsk);
 462 }
 463
 464 static int ptrace_gethbpregs(struct task_struct *tsk, long num,
 465                              unsigned long  __user *data)
 466 {
 467         u32 reg;
 468         int idx, ret = 0;
 469         struct perf_event *bp;
 470         struct arch_hw_breakpoint_ctrl arch_ctrl;
 471
 472         if (num == 0) {
 473                 reg = ptrace_get_hbp_resource_info();
 474         } else {
 475                 idx = ptrace_hbp_num_to_idx(num);
 476                 if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
 477                         ret = -EINVAL;
 478                         goto out;
 479                 }
 480
 481                 bp = tsk->thread.debug.hbp[idx];
 482                 if (!bp) {
 483                         reg = 0;
 484                         goto put;
 485                 }
 486
 487                 arch_ctrl = counter_arch_bp(bp)->ctrl;
 488
 489                 /*
 490                  * Fix up the len because we may have adjusted it
 491                  * to compensate for an unaligned address.
 492                  */
 493                 while (!(arch_ctrl.len & 0x1))
 494                         arch_ctrl.len >>= 1;
 495
 496                 if (num & 0x1)
 497                         reg = bp->attr.bp_addr;
 498                 else
 499                         reg = encode_ctrl_reg(arch_ctrl);
 500         }
 501
 502 put:
 503         if (put_user(reg, data))
 504                 ret = -EFAULT;
 505
 506 out:
 507         return ret;
 508 }
 509
 510 static int ptrace_sethbpregs(struct task_struct *tsk, long num,
 511                              unsigned long __user *data)
 512 {
 513         int idx, gen_len, gen_type, implied_type, ret = 0;
 514         u32 user_val;
 515         struct perf_event *bp;
 516         struct arch_hw_breakpoint_ctrl ctrl;
 517         struct perf_event_attr attr;
 518
 519         if (num == 0)
 520                 goto out;
 521         else if (num < 0)
 522                 implied_type = HW_BREAKPOINT_RW;
 523         else
 524                 implied_type = HW_BREAKPOINT_X;
 525
 526         idx = ptrace_hbp_num_to_idx(num);
 527         if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
 528                 ret = -EINVAL;
 529                 goto out;
 530         }
 531
 532         if (get_user(user_val, data)) {
 533                 ret = -EFAULT;
 534                 goto out;
 535         }
 536
 537         bp = tsk->thread.debug.hbp[idx];
 538         if (!bp) {
 539                 bp = ptrace_hbp_create(tsk, implied_type);
 540                 if (IS_ERR(bp)) {
 541                         ret = PTR_ERR(bp);
 542                         goto out;
 543                 }
 544                 tsk->thread.debug.hbp[idx] = bp;
 545         }
 546
 547         attr = bp->attr;
 548
 549         if (num & 0x1) {
 550                 /* Address */
 551                 attr.bp_addr    = user_val;
 552         } else {
 553                 /* Control */
 554                 decode_ctrl_reg(user_val, &ctrl);
 555                 ret = arch_bp_generic_fields(ctrl, &gen_len, &gen_type);
 556                 if (ret)
 557                         goto out;
 558
 559                 if ((gen_type & implied_type) != gen_type) {
 560                         ret = -EINVAL;
 561                         goto out;
 562                 }
 563
 564                 attr.bp_len     = gen_len;
 565                 attr.bp_type    = gen_type;
 566                 attr.disabled   = !ctrl.enabled;
 567         }
 568
 569         ret = modify_user_hw_breakpoint(bp, &attr);
 570 out:
 571         return ret;
 572 }
 573 #endif
 574
 575 /* regset get/set implementations */
 576
 577 static int gpr_get(struct task_struct *target,
 578                    const struct user_regset *regset,
 579                    unsigned int pos, unsigned int count,
 580                    void *kbuf, void __user *ubuf)
 581 {
 582         struct pt_regs *regs = task_pt_regs(target);
 583
 584         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 585                                    regs,
 586                                    0, sizeof(*regs));
 587 }
 588
 589 static int gpr_set(struct task_struct *target,
 590                    const struct user_regset *regset,
 591                    unsigned int pos, unsigned int count,
 592                    const void *kbuf, const void __user *ubuf)
 593 {
 594         int ret;
 595         struct pt_regs newregs;
 596
 597         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 598                                  &newregs,
 599                                  0, sizeof(newregs));
 600         if (ret)
 601                 return ret;
 602
 603         if (!valid_user_regs(&newregs))
 604                 return -EINVAL;
 605
 606         *task_pt_regs(target) = newregs;
 607         return 0;
 608 }
 609
 610 static int fpa_get(struct task_struct *target,
 611                    const struct user_regset *regset,
 612                    unsigned int pos, unsigned int count,
 613                    void *kbuf, void __user *ubuf)
 614 {
 615         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 616                                    &task_thread_info(target)->fpstate,
 617                                    0, sizeof(struct user_fp));
 618 }
 619
 620 static int fpa_set(struct task_struct *target,
 621                    const struct user_regset *regset,
 622                    unsigned int pos, unsigned int count,
 623                    const void *kbuf, const void __user *ubuf)
 624 {
 625         struct thread_info *thread = task_thread_info(target);
 626
 627         thread->used_cp[1] = thread->used_cp[2] = 1;
 628
 629         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 630                 &thread->fpstate,
 631                 0, sizeof(struct user_fp));
 632 }
 633
 634 #ifdef CONFIG_VFP
 635 /*
 636  * VFP register get/set implementations.
 637  *
 638  * With respect to the kernel, struct user_fp is divided into three chunks:
 639  * 16 or 32 real VFP registers (d0-d15 or d0-31)
 640  *      These are transferred to/from the real registers in the task's
 641  *      vfp_hard_struct.  The number of registers depends on the kernel
 642  *      configuration.
 643  *
 644  * 16 or 0 fake VFP registers (d16-d31 or empty)
 645  *      i.e., the user_vfp structure has space for 32 registers even if
 646  *      the kernel doesn't have them all.
 647  *
 648  *      vfp_get() reads this chunk as zero where applicable
 649  *      vfp_set() ignores this chunk
 650  *
 651  * 1 word for the FPSCR
 652  *
 653  * The bounds-checking logic built into user_regset_copyout and friends
 654  * means that we can make a simple sequence of calls to map the relevant data
 655  * to/from the specified slice of the user regset structure.
 656  */
 657 static int vfp_get(struct task_struct *target,
 658                    const struct user_regset *regset,
 659                    unsigned int pos, unsigned int count,
 660                    void *kbuf, void __user *ubuf)
 661 {
 662         int ret;
 663         struct thread_info *thread = task_thread_info(target);
 664         struct vfp_hard_struct const *vfp = &thread->vfpstate.hard;
 665         const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
 666         const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
 667
 668         vfp_sync_hwstate(thread);
 669
 670         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 671                                   &vfp->fpregs,
 672                                   user_fpregs_offset,
 673                                   user_fpregs_offset + sizeof(vfp->fpregs));
 674         if (ret)
 675                 return ret;
 676
 677         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 678                                        user_fpregs_offset + sizeof(vfp->fpregs),
 679                                        user_fpscr_offset);
 680         if (ret)
 681                 return ret;
 682
 683         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 684                                    &vfp->fpscr,
 685                                    user_fpscr_offset,
 686                                    user_fpscr_offset + sizeof(vfp->fpscr));
 687 }
 688
 689 /*
 690  * For vfp_set() a read-modify-write is done on the VFP registers,
 691  * in order to avoid writing back a half-modified set of registers on
 692  * failure.
 693  */
 694 static int vfp_set(struct task_struct *target,
 695                           const struct user_regset *regset,
 696                           unsigned int pos, unsigned int count,
 697                           const void *kbuf, const void __user *ubuf)
 698 {
 699         int ret;
 700         struct thread_info *thread = task_thread_info(target);
 701         struct vfp_hard_struct new_vfp = thread->vfpstate.hard;
 702         const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
 703         const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
 704
 705         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 706                                   &new_vfp.fpregs,
 707                                   user_fpregs_offset,
 708                                   user_fpregs_offset + sizeof(new_vfp.fpregs));
 709         if (ret)
 710                 return ret;
 711
 712         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 713                                 user_fpregs_offset + sizeof(new_vfp.fpregs),
 714                                 user_fpscr_offset);
 715         if (ret)
 716                 return ret;
 717
 718         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 719                                  &new_vfp.fpscr,
 720                                  user_fpscr_offset,
 721                                  user_fpscr_offset + sizeof(new_vfp.fpscr));
 722         if (ret)
 723                 return ret;
 724
 725         vfp_sync_hwstate(thread);
 726         thread->vfpstate.hard = new_vfp;
 727         vfp_flush_hwstate(thread);
 728
 729         return 0;
 730 }
 731 #endif /* CONFIG_VFP */
 732
 733 enum arm_regset {
 734         REGSET_GPR,
 735         REGSET_FPR,
 736 #ifdef CONFIG_VFP
 737         REGSET_VFP,
 738 #endif
 739 };
 740
 741 static const struct user_regset arm_regsets[] = {
 742         [REGSET_GPR] = {
 743                 .core_note_type = NT_PRSTATUS,
 744                 .n = ELF_NGREG,
 745                 .size = sizeof(u32),
 746                 .align = sizeof(u32),
 747                 .get = gpr_get,
 748                 .set = gpr_set
 749         },
 750         [REGSET_FPR] = {
 751                 /*
 752                  * For the FPA regs in fpstate, the real fields are a mixture
 753                  * of sizes, so pretend that the registers are word-sized:
 754                  */
 755                 .core_note_type = NT_PRFPREG,
 756                 .n = sizeof(struct user_fp) / sizeof(u32),
 757                 .size = sizeof(u32),
 758                 .align = sizeof(u32),
 759                 .get = fpa_get,
 760                 .set = fpa_set
 761         },
 762 #ifdef CONFIG_VFP
 763         [REGSET_VFP] = {
 764                 /*
 765                  * Pretend that the VFP regs are word-sized, since the FPSCR is
 766                  * a single word dangling at the end of struct user_vfp:
 767                  */
 768                 .core_note_type = NT_ARM_VFP,
 769                 .n = ARM_VFPREGS_SIZE / sizeof(u32),
 770                 .size = sizeof(u32),
 771                 .align = sizeof(u32),
 772                 .get = vfp_get,
 773                 .set = vfp_set
 774         },
 775 #endif /* CONFIG_VFP */
 776 };
 777
 778 static const struct user_regset_view user_arm_view = {
 779         .name = "arm", .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI,
 780         .regsets = arm_regsets, .n = ARRAY_SIZE(arm_regsets)
 781 };
 782
 783 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 784 {
 785         return &user_arm_view;
 786 }
 787
 788 long arch_ptrace(struct task_struct *child, long request,
 789                  unsigned long addr, unsigned long data)
 790 {
 791         int ret;
 792         unsigned long __user *datap = (unsigned long __user *) data;
 793
 794         switch (request) {
 795                 case PTRACE_PEEKUSR:
 796                         ret = ptrace_read_user(child, addr, datap);
 797                         break;
 798
 799                 case PTRACE_POKEUSR:
 800                         ret = ptrace_write_user(child, addr, data);
 801                         break;
 802
 803                 case PTRACE_GETREGS:
 804                         ret = copy_regset_to_user(child,
 805                                                   &user_arm_view, REGSET_GPR,
 806                                                   0, sizeof(struct pt_regs),
 807                                                   datap);
 808                         break;
 809
 810                 case PTRACE_SETREGS:
 811                         ret = copy_regset_from_user(child,
 812                                                     &user_arm_view, REGSET_GPR,
 813                                                     0, sizeof(struct pt_regs),
 814                                                     datap);
 815                         break;
 816
 817                 case PTRACE_GETFPREGS:
 818                         ret = copy_regset_to_user(child,
 819                                                   &user_arm_view, REGSET_FPR,
 820                                                   0, sizeof(union fp_state),
 821                                                   datap);
 822                         break;
 823
 824                 case PTRACE_SETFPREGS:
 825                         ret = copy_regset_from_user(child,
 826                                                     &user_arm_view, REGSET_FPR,
 827                                                     0, sizeof(union fp_state),
 828                                                     datap);
 829                         break;
 830
 831 #ifdef CONFIG_IWMMXT
 832                 case PTRACE_GETWMMXREGS:
 833                         ret = ptrace_getwmmxregs(child, datap);
 834                         break;
 835
 836                 case PTRACE_SETWMMXREGS:
 837                         ret = ptrace_setwmmxregs(child, datap);
 838                         break;
 839 #endif
 840
 841                 case PTRACE_GET_THREAD_AREA:
 842                         ret = put_user(task_thread_info(child)->tp_value,
 843                                        datap);
 844                         break;
 845
 846                 case PTRACE_SET_SYSCALL:
 847                         task_thread_info(child)->syscall = data;
 848                         ret = 0;
 849                         break;
 850
 851 #ifdef CONFIG_CRUNCH
 852                 case PTRACE_GETCRUNCHREGS:
 853                         ret = ptrace_getcrunchregs(child, datap);
 854                         break;
 855
 856                 case PTRACE_SETCRUNCHREGS:
 857                         ret = ptrace_setcrunchregs(child, datap);
 858                         break;
 859 #endif
 860
 861 #ifdef CONFIG_VFP
 862                 case PTRACE_GETVFPREGS:
 863                         ret = copy_regset_to_user(child,
 864                                                   &user_arm_view, REGSET_VFP,
 865                                                   0, ARM_VFPREGS_SIZE,
 866                                                   datap);
 867                         break;
 868
 869                 case PTRACE_SETVFPREGS:
 870                         ret = copy_regset_from_user(child,
 871                                                     &user_arm_view, REGSET_VFP,
 872                                                     0, ARM_VFPREGS_SIZE,
 873                                                     datap);
 874                         break;
 875 #endif
 876
 877 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 878                 case PTRACE_GETHBPREGS:
 879                         if (ptrace_get_breakpoints(child) < 0)
 880                                 return -ESRCH;
 881
 882                         ret = ptrace_gethbpregs(child, addr,
 883                                                 (unsigned long __user *)data);
 884                         ptrace_put_breakpoints(child);
 885                         break;
 886                 case PTRACE_SETHBPREGS:
 887                         if (ptrace_get_breakpoints(child) < 0)
 888                                 return -ESRCH;
 889
 890                         ret = ptrace_sethbpregs(child, addr,
 891                                                 (unsigned long __user *)data);
 892                         ptrace_put_breakpoints(child);
 893                         break;
 894 #endif
 895
 896                 default:
 897                         ret = ptrace_request(child, request, addr, data);
 898                         break;
 899         }
 900
 901         return ret;
 902 }
 903
 904 asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
 905 {
 906         unsigned long ip;
 907
 908         if (!test_thread_flag(TIF_SYSCALL_TRACE))
 909                 return scno;
 910         if (!(current->ptrace & PT_PTRACED))
 911                 return scno;
 912
 913         /*
 914          * Save IP.  IP is used to denote syscall entry/exit:
 915          *  IP = 0 -> entry, = 1 -> exit
 916          */
 917         ip = regs->ARM_ip;
 918         regs->ARM_ip = why;
 919
 920         current_thread_info()->syscall = scno;
 921
 922         /* the 0x80 provides a way for the tracing parent to distinguish
 923            between a syscall stop and SIGTRAP delivery */
 924         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 925                                  ? 0x80 : 0));
 926         /*
 927          * this isn't the same as continuing with a signal, but it will do
 928          * for normal use.  strace only continues with a signal if the
 929          * stopping signal is not SIGTRAP.  -brl
 930          */
 931         if (current->exit_code) {
 932                 send_sig(current->exit_code, current, 1);
 933                 current->exit_code = 0;
 934         }
 935         regs->ARM_ip = ip;
 936
 937         return current_thread_info()->syscall;
 938 }