1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * linux/arch/arm/kernel/ptrace.c 4 * 5 * By Ross Biro 1/23/92 6 * edited by Linus Torvalds 7 * ARM modifications Copyright (C) 2000 Russell King 8 */ 9#include <linux/kernel.h> 10#include <linux/sched/signal.h> 11#include <linux/sched/task_stack.h> 12#include <linux/mm.h> 13#include <linux/elf.h> 14#include <linux/smp.h> 15#include <linux/ptrace.h> 16#include <linux/user.h> 17#include <linux/security.h> 18#include <linux/init.h> 19#include <linux/signal.h> 20#include <linux/uaccess.h> 21#include <linux/perf_event.h> 22#include <linux/hw_breakpoint.h> 23#include <linux/regset.h> 24#include <linux/audit.h> 25#include <linux/unistd.h> 26 27#include <asm/syscall.h> 28#include <asm/traps.h> 29 30#define CREATE_TRACE_POINTS 31#include <trace/events/syscalls.h> 32 33#define REG_PC 15 34#define REG_PSR 16 35/* 36 * does not yet catch signals sent when the child dies. 37 * in exit.c or in signal.c. 38 */ 39 40#if 0 41/* 42 * Breakpoint SWI instruction: SWI &9F0001 43 */ 44#define BREAKINST_ARM 0xef9f0001 45#define BREAKINST_THUMB 0xdf00 /* fill this in later */ 46#else 47/* 48 * New breakpoints - use an undefined instruction. The ARM architecture 49 * reference manual guarantees that the following instruction space 50 * will produce an undefined instruction exception on all CPUs: 51 * 52 * ARM: xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx 53 * Thumb: 1101 1110 xxxx xxxx 54 */ 55#define BREAKINST_ARM 0xe7f001f0 56#define BREAKINST_THUMB 0xde01 57#endif 58 59struct pt_regs_offset { 60 const char *name; 61 int offset; 62}; 63 64#define REG_OFFSET_NAME(r) \ 65 {.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)} 66#define REG_OFFSET_END {.name = NULL, .offset = 0} 67 68static const struct pt_regs_offset regoffset_table[] = { 69 REG_OFFSET_NAME(r0), 70 REG_OFFSET_NAME(r1), 71 REG_OFFSET_NAME(r2), 72 REG_OFFSET_NAME(r3), 73 REG_OFFSET_NAME(r4), 74 REG_OFFSET_NAME(r5), 75 REG_OFFSET_NAME(r6), 76 REG_OFFSET_NAME(r7), 77 REG_OFFSET_NAME(r8), 78 REG_OFFSET_NAME(r9), 79 REG_OFFSET_NAME(r10), 80 REG_OFFSET_NAME(fp), 81 REG_OFFSET_NAME(ip), 82 REG_OFFSET_NAME(sp), 83 REG_OFFSET_NAME(lr), 84 REG_OFFSET_NAME(pc), 85 REG_OFFSET_NAME(cpsr), 86 REG_OFFSET_NAME(ORIG_r0), 87 REG_OFFSET_END, 88}; 89 90/** 91 * regs_query_register_offset() - query register offset from its name 92 * @name: the name of a register 93 * 94 * regs_query_register_offset() returns the offset of a register in struct 95 * pt_regs from its name. If the name is invalid, this returns -EINVAL; 96 */ 97int regs_query_register_offset(const char *name) 98{ 99 const struct pt_regs_offset *roff; 100 for (roff = regoffset_table; roff->name != NULL; roff++) 101 if (!strcmp(roff->name, name)) 102 return roff->offset; 103 return -EINVAL; 104} 105 106/** 107 * regs_query_register_name() - query register name from its offset 108 * @offset: the offset of a register in struct pt_regs. 109 * 110 * regs_query_register_name() returns the name of a register from its 111 * offset in struct pt_regs. If the @offset is invalid, this returns NULL; 112 */ 113const char *regs_query_register_name(unsigned int offset) 114{ 115 const struct pt_regs_offset *roff; 116 for (roff = regoffset_table; roff->name != NULL; roff++) 117 if (roff->offset == offset) 118 return roff->name; 119 return NULL; 120} 121 122/** 123 * regs_within_kernel_stack() - check the address in the stack 124 * @regs: pt_regs which contains kernel stack pointer. 125 * @addr: address which is checked. 126 * 127 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 128 * If @addr is within the kernel stack, it returns true. If not, returns false. 129 */ 130bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr) 131{ 132 return ((addr & ~(THREAD_SIZE - 1)) == 133 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 134} 135 136/** 137 * regs_get_kernel_stack_nth() - get Nth entry of the stack 138 * @regs: pt_regs which contains kernel stack pointer. 139 * @n: stack entry number. 140 * 141 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 142 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 143 * this returns 0. 144 */ 145unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n) 146{ 147 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 148 addr += n; 149 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 150 return *addr; 151 else 152 return 0; 153} 154 155/* 156 * this routine will get a word off of the processes privileged stack. 157 * the offset is how far from the base addr as stored in the THREAD. 158 * this routine assumes that all the privileged stacks are in our 159 * data space. 160 */ 161static inline long get_user_reg(struct task_struct *task, int offset) 162{ 163 return task_pt_regs(task)->uregs[offset]; 164} 165 166/* 167 * this routine will put a word on the processes privileged stack. 168 * the offset is how far from the base addr as stored in the THREAD. 169 * this routine assumes that all the privileged stacks are in our 170 * data space. 171 */ 172static inline int 173put_user_reg(struct task_struct *task, int offset, long data) 174{ 175 struct pt_regs newregs, *regs = task_pt_regs(task); 176 int ret = -EINVAL; 177 178 newregs = *regs; 179 newregs.uregs[offset] = data; 180 181 if (valid_user_regs(&newregs)) { 182 regs->uregs[offset] = data; 183 ret = 0; 184 } 185 186 return ret; 187} 188 189/* 190 * Called by kernel/ptrace.c when detaching.. 191 */ 192void ptrace_disable(struct task_struct *child) 193{ 194 /* Nothing to do. */ 195} 196 197/* 198 * Handle hitting a breakpoint. 199 */ 200void ptrace_break(struct pt_regs *regs) 201{ 202 force_sig_fault(SIGTRAP, TRAP_BRKPT, 203 (void __user *)instruction_pointer(regs)); 204} 205 206static int break_trap(struct pt_regs *regs, unsigned int instr) 207{ 208 ptrace_break(regs); 209 return 0; 210} 211 212static struct undef_hook arm_break_hook = { 213 .instr_mask = 0x0fffffff, 214 .instr_val = 0x07f001f0, 215 .cpsr_mask = PSR_T_BIT, 216 .cpsr_val = 0, 217 .fn = break_trap, 218}; 219 220static struct undef_hook thumb_break_hook = { 221 .instr_mask = 0xffffffff, 222 .instr_val = 0x0000de01, 223 .cpsr_mask = PSR_T_BIT, 224 .cpsr_val = PSR_T_BIT, 225 .fn = break_trap, 226}; 227 228static struct undef_hook thumb2_break_hook = { 229 .instr_mask = 0xffffffff, 230 .instr_val = 0xf7f0a000, 231 .cpsr_mask = PSR_T_BIT, 232 .cpsr_val = PSR_T_BIT, 233 .fn = break_trap, 234}; 235 236static int __init ptrace_break_init(void) 237{ 238 register_undef_hook(&arm_break_hook); 239 register_undef_hook(&thumb_break_hook); 240 register_undef_hook(&thumb2_break_hook); 241 return 0; 242} 243 244core_initcall(ptrace_break_init); 245 246/* 247 * Read the word at offset "off" into the "struct user". We 248 * actually access the pt_regs stored on the kernel stack. 249 */ 250static int ptrace_read_user(struct task_struct *tsk, unsigned long off, 251 unsigned long __user *ret) 252{ 253 unsigned long tmp; 254 255 if (off & 3) 256 return -EIO; 257 258 tmp = 0; 259 if (off == PT_TEXT_ADDR) 260 tmp = tsk->mm->start_code; 261 else if (off == PT_DATA_ADDR) 262 tmp = tsk->mm->start_data; 263 else if (off == PT_TEXT_END_ADDR) 264 tmp = tsk->mm->end_code; 265 else if (off < sizeof(struct pt_regs)) 266 tmp = get_user_reg(tsk, off >> 2); 267 else if (off >= sizeof(struct user)) 268 return -EIO; 269 270 return put_user(tmp, ret); 271} 272 273/* 274 * Write the word at offset "off" into "struct user". We 275 * actually access the pt_regs stored on the kernel stack. 276 */ 277static int ptrace_write_user(struct task_struct *tsk, unsigned long off, 278 unsigned long val) 279{ 280 if (off & 3 || off >= sizeof(struct user)) 281 return -EIO; 282 283 if (off >= sizeof(struct pt_regs)) 284 return 0; 285 286 return put_user_reg(tsk, off >> 2, val); 287} 288 289#ifdef CONFIG_IWMMXT 290 291/* 292 * Get the child iWMMXt state. 293 */ 294static int ptrace_getwmmxregs(struct task_struct *tsk, void __user *ufp) 295{ 296 struct thread_info *thread = task_thread_info(tsk); 297 298 if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT)) 299 return -ENODATA; 300 iwmmxt_task_disable(thread); /* force it to ram */ 301 return copy_to_user(ufp, &thread->fpstate.iwmmxt, IWMMXT_SIZE) 302 ? -EFAULT : 0; 303} 304 305/* 306 * Set the child iWMMXt state. 307 */ 308static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp) 309{ 310 struct thread_info *thread = task_thread_info(tsk); 311 312 if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT)) 313 return -EACCES; 314 iwmmxt_task_release(thread); /* force a reload */ 315 return copy_from_user(&thread->fpstate.iwmmxt, ufp, IWMMXT_SIZE) 316 ? -EFAULT : 0; 317} 318 319#endif 320 321#ifdef CONFIG_HAVE_HW_BREAKPOINT 322/* 323 * Convert a virtual register number into an index for a thread_info 324 * breakpoint array. Breakpoints are identified using positive numbers 325 * whilst watchpoints are negative. The registers are laid out as pairs 326 * of (address, control), each pair mapping to a unique hw_breakpoint struct. 327 * Register 0 is reserved for describing resource information. 328 */ 329static int ptrace_hbp_num_to_idx(long num) 330{ 331 if (num < 0) 332 num = (ARM_MAX_BRP << 1) - num; 333 return (num - 1) >> 1; 334} 335 336/* 337 * Returns the virtual register number for the address of the 338 * breakpoint at index idx. 339 */ 340static long ptrace_hbp_idx_to_num(int idx) 341{ 342 long mid = ARM_MAX_BRP << 1; 343 long num = (idx << 1) + 1; 344 return num > mid ? mid - num : num; 345} 346 347/* 348 * Handle hitting a HW-breakpoint. 349 */ 350static void ptrace_hbptriggered(struct perf_event *bp, 351 struct perf_sample_data *data, 352 struct pt_regs *regs) 353{ 354 struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp); 355 long num; 356 int i; 357 358 for (i = 0; i < ARM_MAX_HBP_SLOTS; ++i) 359 if (current->thread.debug.hbp[i] == bp) 360 break; 361 362 num = (i == ARM_MAX_HBP_SLOTS) ? 0 : ptrace_hbp_idx_to_num(i); 363 364 force_sig_ptrace_errno_trap((int)num, (void __user *)(bkpt->trigger)); 365} 366 367/* 368 * Set ptrace breakpoint pointers to zero for this task. 369 * This is required in order to prevent child processes from unregistering 370 * breakpoints held by their parent. 371 */ 372void clear_ptrace_hw_breakpoint(struct task_struct *tsk) 373{ 374 memset(tsk->thread.debug.hbp, 0, sizeof(tsk->thread.debug.hbp)); 375} 376 377/* 378 * Unregister breakpoints from this task and reset the pointers in 379 * the thread_struct. 380 */ 381void flush_ptrace_hw_breakpoint(struct task_struct *tsk) 382{ 383 int i; 384 struct thread_struct *t = &tsk->thread; 385 386 for (i = 0; i < ARM_MAX_HBP_SLOTS; i++) { 387 if (t->debug.hbp[i]) { 388 unregister_hw_breakpoint(t->debug.hbp[i]); 389 t->debug.hbp[i] = NULL; 390 } 391 } 392} 393 394static u32 ptrace_get_hbp_resource_info(void) 395{ 396 u8 num_brps, num_wrps, debug_arch, wp_len; 397 u32 reg = 0; 398 399 num_brps = hw_breakpoint_slots(TYPE_INST); 400 num_wrps = hw_breakpoint_slots(TYPE_DATA); 401 debug_arch = arch_get_debug_arch(); 402 wp_len = arch_get_max_wp_len(); 403 404 reg |= debug_arch; 405 reg <<= 8; 406 reg |= wp_len; 407 reg <<= 8; 408 reg |= num_wrps; 409 reg <<= 8; 410 reg |= num_brps; 411 412 return reg; 413} 414 415static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type) 416{ 417 struct perf_event_attr attr; 418 419 ptrace_breakpoint_init(&attr); 420 421 /* Initialise fields to sane defaults. */ 422 attr.bp_addr = 0; 423 attr.bp_len = HW_BREAKPOINT_LEN_4; 424 attr.bp_type = type; 425 attr.disabled = 1; 426 427 return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, 428 tsk); 429} 430 431static int ptrace_gethbpregs(struct task_struct *tsk, long num, 432 unsigned long __user *data) 433{ 434 u32 reg; 435 int idx, ret = 0; 436 struct perf_event *bp; 437 struct arch_hw_breakpoint_ctrl arch_ctrl; 438 439 if (num == 0) { 440 reg = ptrace_get_hbp_resource_info(); 441 } else { 442 idx = ptrace_hbp_num_to_idx(num); 443 if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) { 444 ret = -EINVAL; 445 goto out; 446 } 447 448 bp = tsk->thread.debug.hbp[idx]; 449 if (!bp) { 450 reg = 0; 451 goto put; 452 } 453 454 arch_ctrl = counter_arch_bp(bp)->ctrl; 455 456 /* 457 * Fix up the len because we may have adjusted it 458 * to compensate for an unaligned address. 459 */ 460 while (!(arch_ctrl.len & 0x1)) 461 arch_ctrl.len >>= 1; 462 463 if (num & 0x1) 464 reg = bp->attr.bp_addr; 465 else 466 reg = encode_ctrl_reg(arch_ctrl); 467 } 468 469put: 470 if (put_user(reg, data)) 471 ret = -EFAULT; 472 473out: 474 return ret; 475} 476 477static int ptrace_sethbpregs(struct task_struct *tsk, long num, 478 unsigned long __user *data) 479{ 480 int idx, gen_len, gen_type, implied_type, ret = 0; 481 u32 user_val; 482 struct perf_event *bp; 483 struct arch_hw_breakpoint_ctrl ctrl; 484 struct perf_event_attr attr; 485 486 if (num == 0) 487 goto out; 488 else if (num < 0) 489 implied_type = HW_BREAKPOINT_RW; 490 else 491 implied_type = HW_BREAKPOINT_X; 492 493 idx = ptrace_hbp_num_to_idx(num); 494 if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) { 495 ret = -EINVAL; 496 goto out; 497 } 498 499 if (get_user(user_val, data)) { 500 ret = -EFAULT; 501 goto out; 502 } 503 504 bp = tsk->thread.debug.hbp[idx]; 505 if (!bp) { 506 bp = ptrace_hbp_create(tsk, implied_type); 507 if (IS_ERR(bp)) { 508 ret = PTR_ERR(bp); 509 goto out; 510 } 511 tsk->thread.debug.hbp[idx] = bp; 512 } 513 514 attr = bp->attr; 515 516 if (num & 0x1) { 517 /* Address */ 518 attr.bp_addr = user_val; 519 } else { 520 /* Control */ 521 decode_ctrl_reg(user_val, &ctrl); 522 ret = arch_bp_generic_fields(ctrl, &gen_len, &gen_type); 523 if (ret) 524 goto out; 525 526 if ((gen_type & implied_type) != gen_type) { 527 ret = -EINVAL; 528 goto out; 529 } 530 531 attr.bp_len = gen_len; 532 attr.bp_type = gen_type; 533 attr.disabled = !ctrl.enabled; 534 } 535 536 ret = modify_user_hw_breakpoint(bp, &attr); 537out: 538 return ret; 539} 540#endif 541 542/* regset get/set implementations */ 543 544static int gpr_get(struct task_struct *target, 545 const struct user_regset *regset, 546 struct membuf to) 547{ 548 return membuf_write(&to, task_pt_regs(target), sizeof(struct pt_regs)); 549} 550 551static int gpr_set(struct task_struct *target, 552 const struct user_regset *regset, 553 unsigned int pos, unsigned int count, 554 const void *kbuf, const void __user *ubuf) 555{ 556 int ret; 557 struct pt_regs newregs = *task_pt_regs(target); 558 559 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 560 &newregs, 561 0, sizeof(newregs)); 562 if (ret) 563 return ret; 564 565 if (!valid_user_regs(&newregs)) 566 return -EINVAL; 567 568 *task_pt_regs(target) = newregs; 569 return 0; 570} 571 572static int fpa_get(struct task_struct *target, 573 const struct user_regset *regset, 574 struct membuf to) 575{ 576 return membuf_write(&to, &task_thread_info(target)->fpstate, 577 sizeof(struct user_fp)); 578} 579 580static int fpa_set(struct task_struct *target, 581 const struct user_regset *regset, 582 unsigned int pos, unsigned int count, 583 const void *kbuf, const void __user *ubuf) 584{ 585 struct thread_info *thread = task_thread_info(target); 586 587 return user_regset_copyin(&pos, &count, &kbuf, &ubuf, 588 &thread->fpstate, 589 0, sizeof(struct user_fp)); 590} 591 592#ifdef CONFIG_VFP 593/* 594 * VFP register get/set implementations. 595 * 596 * With respect to the kernel, struct user_fp is divided into three chunks: 597 * 16 or 32 real VFP registers (d0-d15 or d0-31) 598 * These are transferred to/from the real registers in the task's 599 * vfp_hard_struct. The number of registers depends on the kernel 600 * configuration. 601 * 602 * 16 or 0 fake VFP registers (d16-d31 or empty) 603 * i.e., the user_vfp structure has space for 32 registers even if 604 * the kernel doesn't have them all. 605 * 606 * vfp_get() reads this chunk as zero where applicable 607 * vfp_set() ignores this chunk 608 * 609 * 1 word for the FPSCR 610 */ 611static int vfp_get(struct task_struct *target, 612 const struct user_regset *regset, 613 struct membuf to) 614{ 615 struct thread_info *thread = task_thread_info(target); 616 struct vfp_hard_struct const *vfp = &thread->vfpstate.hard; 617 const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr); 618 619 vfp_sync_hwstate(thread); 620 621 membuf_write(&to, vfp->fpregs, sizeof(vfp->fpregs)); 622 membuf_zero(&to, user_fpscr_offset - sizeof(vfp->fpregs)); 623 return membuf_store(&to, vfp->fpscr); 624} 625 626/* 627 * For vfp_set() a read-modify-write is done on the VFP registers, 628 * in order to avoid writing back a half-modified set of registers on 629 * failure. 630 */ 631static int vfp_set(struct task_struct *target, 632 const struct user_regset *regset, 633 unsigned int pos, unsigned int count, 634 const void *kbuf, const void __user *ubuf) 635{ 636 int ret; 637 struct thread_info *thread = task_thread_info(target); 638 struct vfp_hard_struct new_vfp; 639 const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs); 640 const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr); 641 642 vfp_sync_hwstate(thread); 643 new_vfp = thread->vfpstate.hard; 644 645 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 646 &new_vfp.fpregs, 647 user_fpregs_offset, 648 user_fpregs_offset + sizeof(new_vfp.fpregs)); 649 if (ret) 650 return ret; 651 652 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 653 user_fpregs_offset + sizeof(new_vfp.fpregs), 654 user_fpscr_offset); 655 656 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 657 &new_vfp.fpscr, 658 user_fpscr_offset, 659 user_fpscr_offset + sizeof(new_vfp.fpscr)); 660 if (ret) 661 return ret; 662 663 thread->vfpstate.hard = new_vfp; 664 vfp_flush_hwstate(thread); 665 666 return 0; 667} 668#endif /* CONFIG_VFP */ 669 670enum arm_regset { 671 REGSET_GPR, 672 REGSET_FPR, 673#ifdef CONFIG_VFP 674 REGSET_VFP, 675#endif 676}; 677 678static const struct user_regset arm_regsets[] = { 679 [REGSET_GPR] = { 680 .core_note_type = NT_PRSTATUS, 681 .n = ELF_NGREG, 682 .size = sizeof(u32), 683 .align = sizeof(u32), 684 .regset_get = gpr_get, 685 .set = gpr_set 686 }, 687 [REGSET_FPR] = { 688 /* 689 * For the FPA regs in fpstate, the real fields are a mixture 690 * of sizes, so pretend that the registers are word-sized: 691 */ 692 .core_note_type = NT_PRFPREG, 693 .n = sizeof(struct user_fp) / sizeof(u32), 694 .size = sizeof(u32), 695 .align = sizeof(u32), 696 .regset_get = fpa_get, 697 .set = fpa_set 698 }, 699#ifdef CONFIG_VFP 700 [REGSET_VFP] = { 701 /* 702 * Pretend that the VFP regs are word-sized, since the FPSCR is 703 * a single word dangling at the end of struct user_vfp: 704 */ 705 .core_note_type = NT_ARM_VFP, 706 .n = ARM_VFPREGS_SIZE / sizeof(u32), 707 .size = sizeof(u32), 708 .align = sizeof(u32), 709 .regset_get = vfp_get, 710 .set = vfp_set 711 }, 712#endif /* CONFIG_VFP */ 713}; 714 715static const struct user_regset_view user_arm_view = { 716 .name = "arm", .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI, 717 .regsets = arm_regsets, .n = ARRAY_SIZE(arm_regsets) 718}; 719 720const struct user_regset_view *task_user_regset_view(struct task_struct *task) 721{ 722 return &user_arm_view; 723} 724 725long arch_ptrace(struct task_struct *child, long request, 726 unsigned long addr, unsigned long data) 727{ 728 int ret; 729 unsigned long __user *datap = (unsigned long __user *) data; 730 731 switch (request) { 732 case PTRACE_PEEKUSR: 733 ret = ptrace_read_user(child, addr, datap); 734 break; 735 736 case PTRACE_POKEUSR: 737 ret = ptrace_write_user(child, addr, data); 738 break; 739 740 case PTRACE_GETREGS: 741 ret = copy_regset_to_user(child, 742 &user_arm_view, REGSET_GPR, 743 0, sizeof(struct pt_regs), 744 datap); 745 break; 746 747 case PTRACE_SETREGS: 748 ret = copy_regset_from_user(child, 749 &user_arm_view, REGSET_GPR, 750 0, sizeof(struct pt_regs), 751 datap); 752 break; 753 754 case PTRACE_GETFPREGS: 755 ret = copy_regset_to_user(child, 756 &user_arm_view, REGSET_FPR, 757 0, sizeof(union fp_state), 758 datap); 759 break; 760 761 case PTRACE_SETFPREGS: 762 ret = copy_regset_from_user(child, 763 &user_arm_view, REGSET_FPR, 764 0, sizeof(union fp_state), 765 datap); 766 break; 767 768#ifdef CONFIG_IWMMXT 769 case PTRACE_GETWMMXREGS: 770 ret = ptrace_getwmmxregs(child, datap); 771 break; 772 773 case PTRACE_SETWMMXREGS: 774 ret = ptrace_setwmmxregs(child, datap); 775 break; 776#endif 777 778 case PTRACE_GET_THREAD_AREA: 779 ret = put_user(task_thread_info(child)->tp_value[0], 780 datap); 781 break; 782 783 case PTRACE_SET_SYSCALL: 784 if (data != -1) 785 data &= __NR_SYSCALL_MASK; 786 task_thread_info(child)->abi_syscall = data; 787 ret = 0; 788 break; 789 790#ifdef CONFIG_VFP 791 case PTRACE_GETVFPREGS: 792 ret = copy_regset_to_user(child, 793 &user_arm_view, REGSET_VFP, 794 0, ARM_VFPREGS_SIZE, 795 datap); 796 break; 797 798 case PTRACE_SETVFPREGS: 799 ret = copy_regset_from_user(child, 800 &user_arm_view, REGSET_VFP, 801 0, ARM_VFPREGS_SIZE, 802 datap); 803 break; 804#endif 805 806#ifdef CONFIG_HAVE_HW_BREAKPOINT 807 case PTRACE_GETHBPREGS: 808 ret = ptrace_gethbpregs(child, addr, 809 (unsigned long __user *)data); 810 break; 811 case PTRACE_SETHBPREGS: 812 ret = ptrace_sethbpregs(child, addr, 813 (unsigned long __user *)data); 814 break; 815#endif 816 817 default: 818 ret = ptrace_request(child, request, addr, data); 819 break; 820 } 821 822 return ret; 823} 824 825enum ptrace_syscall_dir { 826 PTRACE_SYSCALL_ENTER = 0, 827 PTRACE_SYSCALL_EXIT, 828}; 829 830static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir) 831{ 832 unsigned long ip; 833 834 /* 835 * IP is used to denote syscall entry/exit: 836 * IP = 0 -> entry, =1 -> exit 837 */ 838 ip = regs->ARM_ip; 839 regs->ARM_ip = dir; 840 841 if (dir == PTRACE_SYSCALL_EXIT) 842 ptrace_report_syscall_exit(regs, 0); 843 else if (ptrace_report_syscall_entry(regs)) 844 current_thread_info()->abi_syscall = -1; 845 846 regs->ARM_ip = ip; 847} 848 849asmlinkage int syscall_trace_enter(struct pt_regs *regs) 850{ 851 int scno; 852 853 if (test_thread_flag(TIF_SYSCALL_TRACE)) 854 report_syscall(regs, PTRACE_SYSCALL_ENTER); 855 856 /* Do seccomp after ptrace; syscall may have changed. */ 857#ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER 858 if (secure_computing() == -1) 859 return -1; 860#else 861 /* XXX: remove this once OABI gets fixed */ 862 secure_computing_strict(syscall_get_nr(current, regs)); 863#endif 864 865 /* Tracer or seccomp may have changed syscall. */ 866 scno = syscall_get_nr(current, regs); 867 868 if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) 869 trace_sys_enter(regs, scno); 870 871 audit_syscall_entry(scno, regs->ARM_r0, regs->ARM_r1, regs->ARM_r2, 872 regs->ARM_r3); 873 874 return scno; 875} 876 877asmlinkage void syscall_trace_exit(struct pt_regs *regs) 878{ 879 /* 880 * Audit the syscall before anything else, as a debugger may 881 * come in and change the current registers. 882 */ 883 audit_syscall_exit(regs); 884 885 /* 886 * Note that we haven't updated the ->syscall field for the 887 * current thread. This isn't a problem because it will have 888 * been set on syscall entry and there hasn't been an opportunity 889 * for a PTRACE_SET_SYSCALL since then. 890 */ 891 if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) 892 trace_sys_exit(regs, regs_return_value(regs)); 893 894 if (test_thread_flag(TIF_SYSCALL_TRACE)) 895 report_syscall(regs, PTRACE_SYSCALL_EXIT); 896} 897