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