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 int thumb2_break_trap(struct pt_regs *regs, unsigned int instr)
 232 {
 233         unsigned int instr2;
 234         void __user *pc;
 235
 236         /* Check the second half of the instruction.  */
 237         pc = (void __user *)(instruction_pointer(regs) + 2);
 238
 239         if (processor_mode(regs) == SVC_MODE) {
 240                 instr2 = *(u16 *) pc;
 241         } else {
 242                 get_user(instr2, (u16 __user *)pc);
 243         }
 244
 245         if (instr2 == 0xa000) {
 246                 ptrace_break(current, regs);
 247                 return 0;
 248         } else {
 249                 return 1;
 250         }
 251 }
 252
 253 static struct undef_hook thumb2_break_hook = {
 254         .instr_mask     = 0xffff,
 255         .instr_val      = 0xf7f0,
 256         .cpsr_mask      = PSR_T_BIT,
 257         .cpsr_val       = PSR_T_BIT,
 258         .fn             = thumb2_break_trap,
 259 };
 260
 261 static int __init ptrace_break_init(void)
 262 {
 263         register_undef_hook(&arm_break_hook);
 264         register_undef_hook(&thumb_break_hook);
 265         register_undef_hook(&thumb2_break_hook);
 266         return 0;
 267 }
 268
 269 core_initcall(ptrace_break_init);
 270
 271 /*
 272  * Read the word at offset "off" into the "struct user".  We
 273  * actually access the pt_regs stored on the kernel stack.
 274  */
 275 static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
 276                             unsigned long __user *ret)
 277 {
 278         unsigned long tmp;
 279
 280         if (off & 3 || off >= sizeof(struct user))
 281                 return -EIO;
 282
 283         tmp = 0;
 284         if (off == PT_TEXT_ADDR)
 285                 tmp = tsk->mm->start_code;
 286         else if (off == PT_DATA_ADDR)
 287                 tmp = tsk->mm->start_data;
 288         else if (off == PT_TEXT_END_ADDR)
 289                 tmp = tsk->mm->end_code;
 290         else if (off < sizeof(struct pt_regs))
 291                 tmp = get_user_reg(tsk, off >> 2);
 292
 293         return put_user(tmp, ret);
 294 }
 295
 296 /*
 297  * Write the word at offset "off" into "struct user".  We
 298  * actually access the pt_regs stored on the kernel stack.
 299  */
 300 static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
 301                              unsigned long val)
 302 {
 303         if (off & 3 || off >= sizeof(struct user))
 304                 return -EIO;
 305
 306         if (off >= sizeof(struct pt_regs))
 307                 return 0;
 308
 309         return put_user_reg(tsk, off >> 2, val);
 310 }
 311
 312 #ifdef CONFIG_IWMMXT
 313
 314 /*
 315  * Get the child iWMMXt state.
 316  */
 317 static int ptrace_getwmmxregs(struct task_struct *tsk, void __user *ufp)
 318 {
 319         struct thread_info *thread = task_thread_info(tsk);
 320
 321         if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
 322                 return -ENODATA;
 323         iwmmxt_task_disable(thread);  /* force it to ram */
 324         return copy_to_user(ufp, &thread->fpstate.iwmmxt, IWMMXT_SIZE)
 325                 ? -EFAULT : 0;
 326 }
 327
 328 /*
 329  * Set the child iWMMXt state.
 330  */
 331 static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp)
 332 {
 333         struct thread_info *thread = task_thread_info(tsk);
 334
 335         if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
 336                 return -EACCES;
 337         iwmmxt_task_release(thread);  /* force a reload */
 338         return copy_from_user(&thread->fpstate.iwmmxt, ufp, IWMMXT_SIZE)
 339                 ? -EFAULT : 0;
 340 }
 341
 342 #endif
 343
 344 #ifdef CONFIG_CRUNCH
 345 /*
 346  * Get the child Crunch state.
 347  */
 348 static int ptrace_getcrunchregs(struct task_struct *tsk, void __user *ufp)
 349 {
 350         struct thread_info *thread = task_thread_info(tsk);
 351
 352         crunch_task_disable(thread);  /* force it to ram */
 353         return copy_to_user(ufp, &thread->crunchstate, CRUNCH_SIZE)
 354                 ? -EFAULT : 0;
 355 }
 356
 357 /*
 358  * Set the child Crunch state.
 359  */
 360 static int ptrace_setcrunchregs(struct task_struct *tsk, void __user *ufp)
 361 {
 362         struct thread_info *thread = task_thread_info(tsk);
 363
 364         crunch_task_release(thread);  /* force a reload */
 365         return copy_from_user(&thread->crunchstate, ufp, CRUNCH_SIZE)
 366                 ? -EFAULT : 0;
 367 }
 368 #endif
 369
 370 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 371 /*
 372  * Convert a virtual register number into an index for a thread_info
 373  * breakpoint array. Breakpoints are identified using positive numbers
 374  * whilst watchpoints are negative. The registers are laid out as pairs
 375  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
 376  * Register 0 is reserved for describing resource information.
 377  */
 378 static int ptrace_hbp_num_to_idx(long num)
 379 {
 380         if (num < 0)
 381                 num = (ARM_MAX_BRP << 1) - num;
 382         return (num - 1) >> 1;
 383 }
 384
 385 /*
 386  * Returns the virtual register number for the address of the
 387  * breakpoint at index idx.
 388  */
 389 static long ptrace_hbp_idx_to_num(int idx)
 390 {
 391         long mid = ARM_MAX_BRP << 1;
 392         long num = (idx << 1) + 1;
 393         return num > mid ? mid - num : num;
 394 }
 395
 396 /*
 397  * Handle hitting a HW-breakpoint.
 398  */
 399 static void ptrace_hbptriggered(struct perf_event *bp, int unused,
 400                                      struct perf_sample_data *data,
 401                                      struct pt_regs *regs)
 402 {
 403         struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
 404         long num;
 405         int i;
 406         siginfo_t info;
 407
 408         for (i = 0; i < ARM_MAX_HBP_SLOTS; ++i)
 409                 if (current->thread.debug.hbp[i] == bp)
 410                         break;
 411
 412         num = (i == ARM_MAX_HBP_SLOTS) ? 0 : ptrace_hbp_idx_to_num(i);
 413
 414         info.si_signo   = SIGTRAP;
 415         info.si_errno   = (int)num;
 416         info.si_code    = TRAP_HWBKPT;
 417         info.si_addr    = (void __user *)(bkpt->trigger);
 418
 419         force_sig_info(SIGTRAP, &info, current);
 420 }
 421
 422 /*
 423  * Set ptrace breakpoint pointers to zero for this task.
 424  * This is required in order to prevent child processes from unregistering
 425  * breakpoints held by their parent.
 426  */
 427 void clear_ptrace_hw_breakpoint(struct task_struct *tsk)
 428 {
 429         memset(tsk->thread.debug.hbp, 0, sizeof(tsk->thread.debug.hbp));
 430 }
 431
 432 /*
 433  * Unregister breakpoints from this task and reset the pointers in
 434  * the thread_struct.
 435  */
 436 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 437 {
 438         int i;
 439         struct thread_struct *t = &tsk->thread;
 440
 441         for (i = 0; i < ARM_MAX_HBP_SLOTS; i++) {
 442                 if (t->debug.hbp[i]) {
 443                         unregister_hw_breakpoint(t->debug.hbp[i]);
 444                         t->debug.hbp[i] = NULL;
 445                 }
 446         }
 447 }
 448
 449 static u32 ptrace_get_hbp_resource_info(void)
 450 {
 451         u8 num_brps, num_wrps, debug_arch, wp_len;
 452         u32 reg = 0;
 453
 454         num_brps        = hw_breakpoint_slots(TYPE_INST);
 455         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
 456         debug_arch      = arch_get_debug_arch();
 457         wp_len          = arch_get_max_wp_len();
 458
 459         reg             |= debug_arch;
 460         reg             <<= 8;
 461         reg             |= wp_len;
 462         reg             <<= 8;
 463         reg             |= num_wrps;
 464         reg             <<= 8;
 465         reg             |= num_brps;
 466
 467         return reg;
 468 }
 469
 470 static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
 471 {
 472         struct perf_event_attr attr;
 473
 474         ptrace_breakpoint_init(&attr);
 475
 476         /* Initialise fields to sane defaults. */
 477         attr.bp_addr    = 0;
 478         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 479         attr.bp_type    = type;
 480         attr.disabled   = 1;
 481
 482         return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, tsk);
 483 }
 484
 485 static int ptrace_gethbpregs(struct task_struct *tsk, long num,
 486                              unsigned long  __user *data)
 487 {
 488         u32 reg;
 489         int idx, ret = 0;
 490         struct perf_event *bp;
 491         struct arch_hw_breakpoint_ctrl arch_ctrl;
 492
 493         if (num == 0) {
 494                 reg = ptrace_get_hbp_resource_info();
 495         } else {
 496                 idx = ptrace_hbp_num_to_idx(num);
 497                 if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
 498                         ret = -EINVAL;
 499                         goto out;
 500                 }
 501
 502                 bp = tsk->thread.debug.hbp[idx];
 503                 if (!bp) {
 504                         reg = 0;
 505                         goto put;
 506                 }
 507
 508                 arch_ctrl = counter_arch_bp(bp)->ctrl;
 509
 510                 /*
 511                  * Fix up the len because we may have adjusted it
 512                  * to compensate for an unaligned address.
 513                  */
 514                 while (!(arch_ctrl.len & 0x1))
 515                         arch_ctrl.len >>= 1;
 516
 517                 if (num & 0x1)
 518                         reg = bp->attr.bp_addr;
 519                 else
 520                         reg = encode_ctrl_reg(arch_ctrl);
 521         }
 522
 523 put:
 524         if (put_user(reg, data))
 525                 ret = -EFAULT;
 526
 527 out:
 528         return ret;
 529 }
 530
 531 static int ptrace_sethbpregs(struct task_struct *tsk, long num,
 532                              unsigned long __user *data)
 533 {
 534         int idx, gen_len, gen_type, implied_type, ret = 0;
 535         u32 user_val;
 536         struct perf_event *bp;
 537         struct arch_hw_breakpoint_ctrl ctrl;
 538         struct perf_event_attr attr;
 539
 540         if (num == 0)
 541                 goto out;
 542         else if (num < 0)
 543                 implied_type = HW_BREAKPOINT_RW;
 544         else
 545                 implied_type = HW_BREAKPOINT_X;
 546
 547         idx = ptrace_hbp_num_to_idx(num);
 548         if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
 549                 ret = -EINVAL;
 550                 goto out;
 551         }
 552
 553         if (get_user(user_val, data)) {
 554                 ret = -EFAULT;
 555                 goto out;
 556         }
 557
 558         bp = tsk->thread.debug.hbp[idx];
 559         if (!bp) {
 560                 bp = ptrace_hbp_create(tsk, implied_type);
 561                 if (IS_ERR(bp)) {
 562                         ret = PTR_ERR(bp);
 563                         goto out;
 564                 }
 565                 tsk->thread.debug.hbp[idx] = bp;
 566         }
 567
 568         attr = bp->attr;
 569
 570         if (num & 0x1) {
 571                 /* Address */
 572                 attr.bp_addr    = user_val;
 573         } else {
 574                 /* Control */
 575                 decode_ctrl_reg(user_val, &ctrl);
 576                 ret = arch_bp_generic_fields(ctrl, &gen_len, &gen_type);
 577                 if (ret)
 578                         goto out;
 579
 580                 if ((gen_type & implied_type) != gen_type) {
 581                         ret = -EINVAL;
 582                         goto out;
 583                 }
 584
 585                 attr.bp_len     = gen_len;
 586                 attr.bp_type    = gen_type;
 587                 attr.disabled   = !ctrl.enabled;
 588         }
 589
 590         ret = modify_user_hw_breakpoint(bp, &attr);
 591 out:
 592         return ret;
 593 }
 594 #endif
 595
 596 /* regset get/set implementations */
 597
 598 static int gpr_get(struct task_struct *target,
 599                    const struct user_regset *regset,
 600                    unsigned int pos, unsigned int count,
 601                    void *kbuf, void __user *ubuf)
 602 {
 603         struct pt_regs *regs = task_pt_regs(target);
 604
 605         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 606                                    regs,
 607                                    0, sizeof(*regs));
 608 }
 609
 610 static int gpr_set(struct task_struct *target,
 611                    const struct user_regset *regset,
 612                    unsigned int pos, unsigned int count,
 613                    const void *kbuf, const void __user *ubuf)
 614 {
 615         int ret;
 616         struct pt_regs newregs;
 617
 618         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 619                                  &newregs,
 620                                  0, sizeof(newregs));
 621         if (ret)
 622                 return ret;
 623
 624         if (!valid_user_regs(&newregs))
 625                 return -EINVAL;
 626
 627         *task_pt_regs(target) = newregs;
 628         return 0;
 629 }
 630
 631 static int fpa_get(struct task_struct *target,
 632                    const struct user_regset *regset,
 633                    unsigned int pos, unsigned int count,
 634                    void *kbuf, void __user *ubuf)
 635 {
 636         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 637                                    &task_thread_info(target)->fpstate,
 638                                    0, sizeof(struct user_fp));
 639 }
 640
 641 static int fpa_set(struct task_struct *target,
 642                    const struct user_regset *regset,
 643                    unsigned int pos, unsigned int count,
 644                    const void *kbuf, const void __user *ubuf)
 645 {
 646         struct thread_info *thread = task_thread_info(target);
 647
 648         thread->used_cp[1] = thread->used_cp[2] = 1;
 649
 650         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 651                 &thread->fpstate,
 652                 0, sizeof(struct user_fp));
 653 }
 654
 655 #ifdef CONFIG_VFP
 656 /*
 657  * VFP register get/set implementations.
 658  *
 659  * With respect to the kernel, struct user_fp is divided into three chunks:
 660  * 16 or 32 real VFP registers (d0-d15 or d0-31)
 661  *      These are transferred to/from the real registers in the task's
 662  *      vfp_hard_struct.  The number of registers depends on the kernel
 663  *      configuration.
 664  *
 665  * 16 or 0 fake VFP registers (d16-d31 or empty)
 666  *      i.e., the user_vfp structure has space for 32 registers even if
 667  *      the kernel doesn't have them all.
 668  *
 669  *      vfp_get() reads this chunk as zero where applicable
 670  *      vfp_set() ignores this chunk
 671  *
 672  * 1 word for the FPSCR
 673  *
 674  * The bounds-checking logic built into user_regset_copyout and friends
 675  * means that we can make a simple sequence of calls to map the relevant data
 676  * to/from the specified slice of the user regset structure.
 677  */
 678 static int vfp_get(struct task_struct *target,
 679                    const struct user_regset *regset,
 680                    unsigned int pos, unsigned int count,
 681                    void *kbuf, void __user *ubuf)
 682 {
 683         int ret;
 684         struct thread_info *thread = task_thread_info(target);
 685         struct vfp_hard_struct const *vfp = &thread->vfpstate.hard;
 686         const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
 687         const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
 688
 689         vfp_sync_hwstate(thread);
 690
 691         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 692                                   &vfp->fpregs,
 693                                   user_fpregs_offset,
 694                                   user_fpregs_offset + sizeof(vfp->fpregs));
 695         if (ret)
 696                 return ret;
 697
 698         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 699                                        user_fpregs_offset + sizeof(vfp->fpregs),
 700                                        user_fpscr_offset);
 701         if (ret)
 702                 return ret;
 703
 704         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 705                                    &vfp->fpscr,
 706                                    user_fpscr_offset,
 707                                    user_fpscr_offset + sizeof(vfp->fpscr));
 708 }
 709
 710 /*
 711  * For vfp_set() a read-modify-write is done on the VFP registers,
 712  * in order to avoid writing back a half-modified set of registers on
 713  * failure.
 714  */
 715 static int vfp_set(struct task_struct *target,
 716                           const struct user_regset *regset,
 717                           unsigned int pos, unsigned int count,
 718                           const void *kbuf, const void __user *ubuf)
 719 {
 720         int ret;
 721         struct thread_info *thread = task_thread_info(target);
 722         struct vfp_hard_struct new_vfp = thread->vfpstate.hard;
 723         const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
 724         const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
 725
 726         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 727                                   &new_vfp.fpregs,
 728                                   user_fpregs_offset,
 729                                   user_fpregs_offset + sizeof(new_vfp.fpregs));
 730         if (ret)
 731                 return ret;
 732
 733         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 734                                 user_fpregs_offset + sizeof(new_vfp.fpregs),
 735                                 user_fpscr_offset);
 736         if (ret)
 737                 return ret;
 738
 739         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 740                                  &new_vfp.fpscr,
 741                                  user_fpscr_offset,
 742                                  user_fpscr_offset + sizeof(new_vfp.fpscr));
 743         if (ret)
 744                 return ret;
 745
 746         vfp_sync_hwstate(thread);
 747         thread->vfpstate.hard = new_vfp;
 748         vfp_flush_hwstate(thread);
 749
 750         return 0;
 751 }
 752 #endif /* CONFIG_VFP */
 753
 754 enum arm_regset {
 755         REGSET_GPR,
 756         REGSET_FPR,
 757 #ifdef CONFIG_VFP
 758         REGSET_VFP,
 759 #endif
 760 };
 761
 762 static const struct user_regset arm_regsets[] = {
 763         [REGSET_GPR] = {
 764                 .core_note_type = NT_PRSTATUS,
 765                 .n = ELF_NGREG,
 766                 .size = sizeof(u32),
 767                 .align = sizeof(u32),
 768                 .get = gpr_get,
 769                 .set = gpr_set
 770         },
 771         [REGSET_FPR] = {
 772                 /*
 773                  * For the FPA regs in fpstate, the real fields are a mixture
 774                  * of sizes, so pretend that the registers are word-sized:
 775                  */
 776                 .core_note_type = NT_PRFPREG,
 777                 .n = sizeof(struct user_fp) / sizeof(u32),
 778                 .size = sizeof(u32),
 779                 .align = sizeof(u32),
 780                 .get = fpa_get,
 781                 .set = fpa_set
 782         },
 783 #ifdef CONFIG_VFP
 784         [REGSET_VFP] = {
 785                 /*
 786                  * Pretend that the VFP regs are word-sized, since the FPSCR is
 787                  * a single word dangling at the end of struct user_vfp:
 788                  */
 789                 .core_note_type = NT_ARM_VFP,
 790                 .n = ARM_VFPREGS_SIZE / sizeof(u32),
 791                 .size = sizeof(u32),
 792                 .align = sizeof(u32),
 793                 .get = vfp_get,
 794                 .set = vfp_set
 795         },
 796 #endif /* CONFIG_VFP */
 797 };
 798
 799 static const struct user_regset_view user_arm_view = {
 800         .name = "arm", .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI,
 801         .regsets = arm_regsets, .n = ARRAY_SIZE(arm_regsets)
 802 };
 803
 804 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 805 {
 806         return &user_arm_view;
 807 }
 808
 809 long arch_ptrace(struct task_struct *child, long request,
 810                  unsigned long addr, unsigned long data)
 811 {
 812         int ret;
 813         unsigned long __user *datap = (unsigned long __user *) data;
 814
 815         switch (request) {
 816                 case PTRACE_PEEKUSR:
 817                         ret = ptrace_read_user(child, addr, datap);
 818                         break;
 819
 820                 case PTRACE_POKEUSR:
 821                         ret = ptrace_write_user(child, addr, data);
 822                         break;
 823
 824                 case PTRACE_GETREGS:
 825                         ret = copy_regset_to_user(child,
 826                                                   &user_arm_view, REGSET_GPR,
 827                                                   0, sizeof(struct pt_regs),
 828                                                   datap);
 829                         break;
 830
 831                 case PTRACE_SETREGS:
 832                         ret = copy_regset_from_user(child,
 833                                                     &user_arm_view, REGSET_GPR,
 834                                                     0, sizeof(struct pt_regs),
 835                                                     datap);
 836                         break;
 837
 838                 case PTRACE_GETFPREGS:
 839                         ret = copy_regset_to_user(child,
 840                                                   &user_arm_view, REGSET_FPR,
 841                                                   0, sizeof(union fp_state),
 842                                                   datap);
 843                         break;
 844
 845                 case PTRACE_SETFPREGS:
 846                         ret = copy_regset_from_user(child,
 847                                                     &user_arm_view, REGSET_FPR,
 848                                                     0, sizeof(union fp_state),
 849                                                     datap);
 850                         break;
 851
 852 #ifdef CONFIG_IWMMXT
 853                 case PTRACE_GETWMMXREGS:
 854                         ret = ptrace_getwmmxregs(child, datap);
 855                         break;
 856
 857                 case PTRACE_SETWMMXREGS:
 858                         ret = ptrace_setwmmxregs(child, datap);
 859                         break;
 860 #endif
 861
 862                 case PTRACE_GET_THREAD_AREA:
 863                         ret = put_user(task_thread_info(child)->tp_value,
 864                                        datap);
 865                         break;
 866
 867                 case PTRACE_SET_SYSCALL:
 868                         task_thread_info(child)->syscall = data;
 869                         ret = 0;
 870                         break;
 871
 872 #ifdef CONFIG_CRUNCH
 873                 case PTRACE_GETCRUNCHREGS:
 874                         ret = ptrace_getcrunchregs(child, datap);
 875                         break;
 876
 877                 case PTRACE_SETCRUNCHREGS:
 878                         ret = ptrace_setcrunchregs(child, datap);
 879                         break;
 880 #endif
 881
 882 #ifdef CONFIG_VFP
 883                 case PTRACE_GETVFPREGS:
 884                         ret = copy_regset_to_user(child,
 885                                                   &user_arm_view, REGSET_VFP,
 886                                                   0, ARM_VFPREGS_SIZE,
 887                                                   datap);
 888                         break;
 889
 890                 case PTRACE_SETVFPREGS:
 891                         ret = copy_regset_from_user(child,
 892                                                     &user_arm_view, REGSET_VFP,
 893                                                     0, ARM_VFPREGS_SIZE,
 894                                                     datap);
 895                         break;
 896 #endif
 897
 898 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 899                 case PTRACE_GETHBPREGS:
 900                         if (ptrace_get_breakpoints(child) < 0)
 901                                 return -ESRCH;
 902
 903                         ret = ptrace_gethbpregs(child, addr,
 904                                                 (unsigned long __user *)data);
 905                         ptrace_put_breakpoints(child);
 906                         break;
 907                 case PTRACE_SETHBPREGS:
 908                         if (ptrace_get_breakpoints(child) < 0)
 909                                 return -ESRCH;
 910
 911                         ret = ptrace_sethbpregs(child, addr,
 912                                                 (unsigned long __user *)data);
 913                         ptrace_put_breakpoints(child);
 914                         break;
 915 #endif
 916
 917                 default:
 918                         ret = ptrace_request(child, request, addr, data);
 919                         break;
 920         }
 921
 922         return ret;
 923 }
 924
 925 asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
 926 {
 927         unsigned long ip;
 928
 929         if (!test_thread_flag(TIF_SYSCALL_TRACE))
 930                 return scno;
 931         if (!(current->ptrace & PT_PTRACED))
 932                 return scno;
 933
 934         /*
 935          * Save IP.  IP is used to denote syscall entry/exit:
 936          *  IP = 0 -> entry, = 1 -> exit
 937          */
 938         ip = regs->ARM_ip;
 939         regs->ARM_ip = why;
 940
 941         current_thread_info()->syscall = scno;
 942
 943         /* the 0x80 provides a way for the tracing parent to distinguish
 944            between a syscall stop and SIGTRAP delivery */
 945         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 946                                  ? 0x80 : 0));
 947         /*
 948          * this isn't the same as continuing with a signal, but it will do
 949          * for normal use.  strace only continues with a signal if the
 950          * stopping signal is not SIGTRAP.  -brl
 951          */
 952         if (current->exit_code) {
 953                 send_sig(current->exit_code, current, 1);
 954                 current->exit_code = 0;
 955         }
 956         regs->ARM_ip = ip;
 957
 958         return current_thread_info()->syscall;
 959 }