/* * recordmcount.h * * This code was taken out of recordmcount.c written by * Copyright 2009 John F. Reiser . All rights reserved. * * The original code had the same algorithms for both 32bit * and 64bit ELF files, but the code was duplicated to support * the difference in structures that were used. This * file creates a macro of everything that is different between * the 64 and 32 bit code, such that by including this header * twice we can create both sets of functions by including this * header once with RECORD_MCOUNT_64 undefined, and again with * it defined. * * This conversion to macros was done by: * Copyright 2010 Steven Rostedt , Red Hat Inc. * * Licensed under the GNU General Public License, version 2 (GPLv2). */ #undef append_func #undef is_fake_mcount #undef fn_is_fake_mcount #undef MIPS_is_fake_mcount #undef mcount_adjust #undef sift_rel_mcount #undef nop_mcount #undef find_secsym_ndx #undef __has_rel_mcount #undef has_rel_mcount #undef tot_relsize #undef get_mcountsym #undef get_sym_str_and_relp #undef do_func #undef Elf_Addr #undef Elf_Ehdr #undef Elf_Shdr #undef Elf_Rel #undef Elf_Rela #undef Elf_Sym #undef ELF_R_SYM #undef Elf_r_sym #undef ELF_R_INFO #undef Elf_r_info #undef ELF_ST_BIND #undef ELF_ST_TYPE #undef fn_ELF_R_SYM #undef fn_ELF_R_INFO #undef uint_t #undef _w #undef _align #undef _size #ifdef RECORD_MCOUNT_64 # define append_func append64 # define sift_rel_mcount sift64_rel_mcount # define nop_mcount nop_mcount_64 # define find_secsym_ndx find64_secsym_ndx # define __has_rel_mcount __has64_rel_mcount # define has_rel_mcount has64_rel_mcount # define tot_relsize tot64_relsize # define get_sym_str_and_relp get_sym_str_and_relp_64 # define do_func do64 # define get_mcountsym get_mcountsym_64 # define is_fake_mcount is_fake_mcount64 # define fn_is_fake_mcount fn_is_fake_mcount64 # define MIPS_is_fake_mcount MIPS64_is_fake_mcount # define mcount_adjust mcount_adjust_64 # define Elf_Addr Elf64_Addr # define Elf_Ehdr Elf64_Ehdr # define Elf_Shdr Elf64_Shdr # define Elf_Rel Elf64_Rel # define Elf_Rela Elf64_Rela # define Elf_Sym Elf64_Sym # define ELF_R_SYM ELF64_R_SYM # define Elf_r_sym Elf64_r_sym # define ELF_R_INFO ELF64_R_INFO # define Elf_r_info Elf64_r_info # define ELF_ST_BIND ELF64_ST_BIND # define ELF_ST_TYPE ELF64_ST_TYPE # define fn_ELF_R_SYM fn_ELF64_R_SYM # define fn_ELF_R_INFO fn_ELF64_R_INFO # define uint_t uint64_t # define _w w8 # define _align 7u # define _size 8 #else # define append_func append32 # define sift_rel_mcount sift32_rel_mcount # define nop_mcount nop_mcount_32 # define find_secsym_ndx find32_secsym_ndx # define __has_rel_mcount __has32_rel_mcount # define has_rel_mcount has32_rel_mcount # define tot_relsize tot32_relsize # define get_sym_str_and_relp get_sym_str_and_relp_32 # define do_func do32 # define get_mcountsym get_mcountsym_32 # define is_fake_mcount is_fake_mcount32 # define fn_is_fake_mcount fn_is_fake_mcount32 # define MIPS_is_fake_mcount MIPS32_is_fake_mcount # define mcount_adjust mcount_adjust_32 # define Elf_Addr Elf32_Addr # define Elf_Ehdr Elf32_Ehdr # define Elf_Shdr Elf32_Shdr # define Elf_Rel Elf32_Rel # define Elf_Rela Elf32_Rela # define Elf_Sym Elf32_Sym # define ELF_R_SYM ELF32_R_SYM # define Elf_r_sym Elf32_r_sym # define ELF_R_INFO ELF32_R_INFO # define Elf_r_info Elf32_r_info # define ELF_ST_BIND ELF32_ST_BIND # define ELF_ST_TYPE ELF32_ST_TYPE # define fn_ELF_R_SYM fn_ELF32_R_SYM # define fn_ELF_R_INFO fn_ELF32_R_INFO # define uint_t uint32_t # define _w w # define _align 3u # define _size 4 #endif /* Functions and pointers that do_file() may override for specific e_machine. */ static int fn_is_fake_mcount(Elf_Rel const *rp) { return 0; } static int (*is_fake_mcount)(Elf_Rel const *rp) = fn_is_fake_mcount; static uint_t fn_ELF_R_SYM(Elf_Rel const *rp) { return ELF_R_SYM(_w(rp->r_info)); } static uint_t (*Elf_r_sym)(Elf_Rel const *rp) = fn_ELF_R_SYM; static void fn_ELF_R_INFO(Elf_Rel *const rp, unsigned sym, unsigned type) { rp->r_info = _w(ELF_R_INFO(sym, type)); } static void (*Elf_r_info)(Elf_Rel *const rp, unsigned sym, unsigned type) = fn_ELF_R_INFO; static int mcount_adjust = 0; /* * MIPS mcount long call has 2 _mcount symbols, only the position of the 1st * _mcount symbol is needed for dynamic function tracer, with it, to disable * tracing(ftrace_make_nop), the instruction in the position is replaced with * the "b label" instruction, to enable tracing(ftrace_make_call), replace the * instruction back. So, here, we set the 2nd one as fake and filter it. * * c: 3c030000 lui v1,0x0 <--> b label * c: R_MIPS_HI16 _mcount * c: R_MIPS_NONE *ABS* * c: R_MIPS_NONE *ABS* * 10: 64630000 daddiu v1,v1,0 * 10: R_MIPS_LO16 _mcount * 10: R_MIPS_NONE *ABS* * 10: R_MIPS_NONE *ABS* * 14: 03e0082d move at,ra * 18: 0060f809 jalr v1 * label: */ #define MIPS_FAKEMCOUNT_OFFSET 4 static int MIPS_is_fake_mcount(Elf_Rel const *rp) { static Elf_Addr old_r_offset = ~(Elf_Addr)0; Elf_Addr current_r_offset = _w(rp->r_offset); int is_fake; is_fake = (old_r_offset != ~(Elf_Addr)0) && (current_r_offset - old_r_offset == MIPS_FAKEMCOUNT_OFFSET); old_r_offset = current_r_offset; return is_fake; } /* Append the new shstrtab, Elf_Shdr[], __mcount_loc and its relocations. */ static void append_func(Elf_Ehdr *const ehdr, Elf_Shdr *const shstr, uint_t const *const mloc0, uint_t const *const mlocp, Elf_Rel const *const mrel0, Elf_Rel const *const mrelp, unsigned int const rel_entsize, unsigned int const symsec_sh_link) { /* Begin constructing output file */ Elf_Shdr mcsec; char const *mc_name = (sizeof(Elf_Rela) == rel_entsize) ? ".rela__mcount_loc" : ".rel__mcount_loc"; unsigned const old_shnum = w2(ehdr->e_shnum); uint_t const old_shoff = _w(ehdr->e_shoff); uint_t const old_shstr_sh_size = _w(shstr->sh_size); uint_t const old_shstr_sh_offset = _w(shstr->sh_offset); uint_t t = 1 + strlen(mc_name) + _w(shstr->sh_size); uint_t new_e_shoff; shstr->sh_size = _w(t); shstr->sh_offset = _w(sb.st_size); t += sb.st_size; t += (_align & -t); /* word-byte align */ new_e_shoff = t; /* body for new shstrtab */ ulseek(fd_map, sb.st_size, SEEK_SET); uwrite(fd_map, old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size); uwrite(fd_map, mc_name, 1 + strlen(mc_name)); /* old(modified) Elf_Shdr table, word-byte aligned */ ulseek(fd_map, t, SEEK_SET); t += sizeof(Elf_Shdr) * old_shnum; uwrite(fd_map, old_shoff + (void *)ehdr, sizeof(Elf_Shdr) * old_shnum); /* new sections __mcount_loc and .rel__mcount_loc */ t += 2*sizeof(mcsec); mcsec.sh_name = w((sizeof(Elf_Rela) == rel_entsize) + strlen(".rel") + old_shstr_sh_size); mcsec.sh_type = w(SHT_PROGBITS); mcsec.sh_flags = _w(SHF_ALLOC); mcsec.sh_addr = 0; mcsec.sh_offset = _w(t); mcsec.sh_size = _w((void *)mlocp - (void *)mloc0); mcsec.sh_link = 0; mcsec.sh_info = 0; mcsec.sh_addralign = _w(_size); mcsec.sh_entsize = _w(_size); uwrite(fd_map, &mcsec, sizeof(mcsec)); mcsec.sh_name = w(old_shstr_sh_size); mcsec.sh_type = (sizeof(Elf_Rela) == rel_entsize) ? w(SHT_RELA) : w(SHT_REL); mcsec.sh_flags = 0; mcsec.sh_addr = 0; mcsec.sh_offset = _w((void *)mlocp - (void *)mloc0 + t); mcsec.sh_size = _w((void *)mrelp - (void *)mrel0); mcsec.sh_link = w(symsec_sh_link); mcsec.sh_info = w(old_shnum); mcsec.sh_addralign = _w(_size); mcsec.sh_entsize = _w(rel_entsize); uwrite(fd_map, &mcsec, sizeof(mcsec)); uwrite(fd_map, mloc0, (void *)mlocp - (void *)mloc0); uwrite(fd_map, mrel0, (void *)mrelp - (void *)mrel0); ehdr->e_shoff = _w(new_e_shoff); ehdr->e_shnum = w2(2 + w2(ehdr->e_shnum)); /* {.rel,}__mcount_loc */ ulseek(fd_map, 0, SEEK_SET); uwrite(fd_map, ehdr, sizeof(*ehdr)); } static unsigned get_mcountsym(Elf_Sym const *const sym0, Elf_Rel const *relp, char const *const str0) { unsigned mcountsym = 0; Elf_Sym const *const symp = &sym0[Elf_r_sym(relp)]; char const *symname = &str0[w(symp->st_name)]; char const *mcount = gpfx == '_' ? "_mcount" : "mcount"; char const *fentry = "__fentry__"; if (symname[0] == '.') ++symname; /* ppc64 hack */ if (strcmp(mcount, symname) == 0 || (altmcount && strcmp(altmcount, symname) == 0) || (strcmp(fentry, symname) == 0)) mcountsym = Elf_r_sym(relp); return mcountsym; } static void get_sym_str_and_relp(Elf_Shdr const *const relhdr, Elf_Ehdr const *const ehdr, Elf_Sym const **sym0, char const **str0, Elf_Rel const **relp) { Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff) + (void *)ehdr); unsigned const symsec_sh_link = w(relhdr->sh_link); Elf_Shdr const *const symsec = &shdr0[symsec_sh_link]; Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)]; Elf_Rel const *const rel0 = (Elf_Rel const *)(_w(relhdr->sh_offset) + (void *)ehdr); *sym0 = (Elf_Sym const *)(_w(symsec->sh_offset) + (void *)ehdr); *str0 = (char const *)(_w(strsec->sh_offset) + (void *)ehdr); *relp = rel0; } /* * Look at the relocations in order to find the calls to mcount. * Accumulate the section offsets that are found, and their relocation info, * onto the end of the existing arrays. */ static uint_t *sift_rel_mcount(uint_t *mlocp, unsigned const offbase, Elf_Rel **const mrelpp, Elf_Shdr const *const relhdr, Elf_Ehdr const *const ehdr, unsigned const recsym, uint_t const recval, unsigned const reltype) { uint_t *const mloc0 = mlocp; Elf_Rel *mrelp = *mrelpp; Elf_Sym const *sym0; char const *str0; Elf_Rel const *relp; unsigned rel_entsize = _w(relhdr->sh_entsize); unsigned const nrel = _w(relhdr->sh_size) / rel_entsize; unsigned mcountsym = 0; unsigned t; get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp); for (t = nrel; t; --t) { if (!mcountsym) mcountsym = get_mcountsym(sym0, relp, str0); if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) { uint_t const addend = _w(_w(relp->r_offset) - recval + mcount_adjust); mrelp->r_offset = _w(offbase + ((void *)mlocp - (void *)mloc0)); Elf_r_info(mrelp, recsym, reltype); if (rel_entsize == sizeof(Elf_Rela)) { ((Elf_Rela *)mrelp)->r_addend = addend; *mlocp++ = 0; } else *mlocp++ = addend; mrelp = (Elf_Rel *)(rel_entsize + (void *)mrelp); } relp = (Elf_Rel const *)(rel_entsize + (void *)relp); } *mrelpp = mrelp; return mlocp; } /* * Read the relocation table again, but this time its called on sections * that are not going to be traced. The mcount calls here will be converted * into nops. */ static void nop_mcount(Elf_Shdr const *const relhdr, Elf_Ehdr const *const ehdr, const char *const txtname) { Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff) + (void *)ehdr); Elf_Sym const *sym0; char const *str0; Elf_Rel const *relp; Elf_Shdr const *const shdr = &shdr0[w(relhdr->sh_info)]; unsigned rel_entsize = _w(relhdr->sh_entsize); unsigned const nrel = _w(relhdr->sh_size) / rel_entsize; unsigned mcountsym = 0; unsigned t; int once = 0; get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp); for (t = nrel; t; --t) { int ret = -1; if (!mcountsym) mcountsym = get_mcountsym(sym0, relp, str0); if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) { if (make_nop) ret = make_nop((void *)ehdr, _w(shdr->sh_offset) + _w(relp->r_offset)); if (warn_on_notrace_sect && !once) { printf("Section %s has mcount callers being ignored\n", txtname); once = 1; /* just warn? */ if (!make_nop) return; } } /* * If we successfully removed the mcount, mark the relocation * as a nop (don't do anything with it). */ if (!ret) { Elf_Rel rel; rel = *(Elf_Rel *)relp; Elf_r_info(&rel, Elf_r_sym(relp), rel_type_nop); ulseek(fd_map, (void *)relp - (void *)ehdr, SEEK_SET); uwrite(fd_map, &rel, sizeof(rel)); } relp = (Elf_Rel const *)(rel_entsize + (void *)relp); } } /* * Find a symbol in the given section, to be used as the base for relocating * the table of offsets of calls to mcount. A local or global symbol suffices, * but avoid a Weak symbol because it may be overridden; the change in value * would invalidate the relocations of the offsets of the calls to mcount. * Often the found symbol will be the unnamed local symbol generated by * GNU 'as' for the start of each section. For example: * Num: Value Size Type Bind Vis Ndx Name * 2: 00000000 0 SECTION LOCAL DEFAULT 1 */ static unsigned find_secsym_ndx(unsigned const txtndx, char const *const txtname, uint_t *const recvalp, Elf_Shdr const *const symhdr, Elf_Ehdr const *const ehdr) { Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symhdr->sh_offset) + (void *)ehdr); unsigned const nsym = _w(symhdr->sh_size) / _w(symhdr->sh_entsize); Elf_Sym const *symp; unsigned t; for (symp = sym0, t = nsym; t; --t, ++symp) { unsigned int const st_bind = ELF_ST_BIND(symp->st_info); if (txtndx == w2(symp->st_shndx) /* avoid STB_WEAK */ && (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) { /* function symbols on ARM have quirks, avoid them */ if (w2(ehdr->e_machine) == EM_ARM && ELF_ST_TYPE(symp->st_info) == STT_FUNC) continue; *recvalp = _w(symp->st_value); return symp - sym0; } } fprintf(stderr, "Cannot find symbol for section %d: %s.\n", txtndx, txtname); fail_file(); } /* Evade ISO C restriction: no declaration after statement in has_rel_mcount. */ static char const * __has_rel_mcount(Elf_Shdr const *const relhdr, /* is SHT_REL or SHT_RELA */ Elf_Shdr const *const shdr0, char const *const shstrtab, char const *const fname) { /* .sh_info depends on .sh_type == SHT_REL[,A] */ Elf_Shdr const *const txthdr = &shdr0[w(relhdr->sh_info)]; char const *const txtname = &shstrtab[w(txthdr->sh_name)]; if (strcmp("__mcount_loc", txtname) == 0) { fprintf(stderr, "warning: __mcount_loc already exists: %s\n", fname); succeed_file(); } if (w(txthdr->sh_type) != SHT_PROGBITS || !(_w(txthdr->sh_flags) & SHF_EXECINSTR)) return NULL; return txtname; } static char const *has_rel_mcount(Elf_Shdr const *const relhdr, Elf_Shdr const *const shdr0, char const *const shstrtab, char const *const fname) { if (w(relhdr->sh_type) != SHT_REL && w(relhdr->sh_type) != SHT_RELA) return NULL; return __has_rel_mcount(relhdr, shdr0, shstrtab, fname); } static unsigned tot_relsize(Elf_Shdr const *const shdr0, unsigned nhdr, const char *const shstrtab, const char *const fname) { unsigned totrelsz = 0; Elf_Shdr const *shdrp = shdr0; char const *txtname; for (; nhdr; --nhdr, ++shdrp) { txtname = has_rel_mcount(shdrp, shdr0, shstrtab, fname); if (txtname && is_mcounted_section_name(txtname)) totrelsz += _w(shdrp->sh_size); } return totrelsz; } /* Overall supervision for Elf32 ET_REL file. */ static void do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype) { Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff) + (void *)ehdr); unsigned const nhdr = w2(ehdr->e_shnum); Elf_Shdr *const shstr = &shdr0[w2(ehdr->e_shstrndx)]; char const *const shstrtab = (char const *)(_w(shstr->sh_offset) + (void *)ehdr); Elf_Shdr const *relhdr; unsigned k; /* Upper bound on space: assume all relevant relocs are for mcount. */ unsigned const totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname); Elf_Rel *const mrel0 = umalloc(totrelsz); Elf_Rel * mrelp = mrel0; /* 2*sizeof(address) <= sizeof(Elf_Rel) */ uint_t *const mloc0 = umalloc(totrelsz>>1); uint_t * mlocp = mloc0; unsigned rel_entsize = 0; unsigned symsec_sh_link = 0; for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) { char const *const txtname = has_rel_mcount(relhdr, shdr0, shstrtab, fname); if (txtname && is_mcounted_section_name(txtname)) { uint_t recval = 0; unsigned const recsym = find_secsym_ndx( w(relhdr->sh_info), txtname, &recval, &shdr0[symsec_sh_link = w(relhdr->sh_link)], ehdr); rel_entsize = _w(relhdr->sh_entsize); mlocp = sift_rel_mcount(mlocp, (void *)mlocp - (void *)mloc0, &mrelp, relhdr, ehdr, recsym, recval, reltype); } else if (txtname && (warn_on_notrace_sect || make_nop)) { /* * This section is ignored by ftrace, but still * has mcount calls. Convert them to nops now. */ nop_mcount(relhdr, ehdr, txtname); } } if (mloc0 != mlocp) { append_func(ehdr, shstr, mloc0, mlocp, mrel0, mrelp, rel_entsize, symsec_sh_link); } free(mrel0); free(mloc0); } href='#n383'>383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 
/*
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
 *
 *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
 *  2000-06-20  Pentium III FXSR, SSE support by Gareth Hughes
 *  2000-2002   x86-64 support by Andi Kleen
 */

#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/tracehook.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/uaccess.h>

#include <asm/processor.h>
#include <asm/ucontext.h>
#include <asm/i387.h>
#include <asm/vdso.h>

#ifdef CONFIG_X86_64
#include <asm/proto.h>
#include <asm/ia32_unistd.h>
#include <asm/mce.h>
#endif /* CONFIG_X86_64 */

#include <asm/syscall.h>
#include <asm/syscalls.h>

#include <asm/sigframe.h>

#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))

#define __FIX_EFLAGS	(X86_EFLAGS_AC | X86_EFLAGS_OF | \
			 X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \
			 X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \
			 X86_EFLAGS_CF)

#ifdef CONFIG_X86_32
# define FIX_EFLAGS	(__FIX_EFLAGS | X86_EFLAGS_RF)
#else
# define FIX_EFLAGS	__FIX_EFLAGS
#endif

#define COPY(x)			{		\
	err |= __get_user(regs->x, &sc->x);	\
}

#define COPY_SEG(seg)		{			\
		unsigned short tmp;			\
		err |= __get_user(tmp, &sc->seg);	\
		regs->seg = tmp;			\
}

#define COPY_SEG_CPL3(seg)	{			\
		unsigned short tmp;			\
		err |= __get_user(tmp, &sc->seg);	\
		regs->seg = tmp | 3;			\
}

#define GET_SEG(seg)		{			\
		unsigned short tmp;			\
		err |= __get_user(tmp, &sc->seg);	\
		loadsegment(seg, tmp);			\
}

static int
restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
		   unsigned long *pax)
{
	void __user *buf;
	unsigned int tmpflags;
	unsigned int err = 0;

	/* Always make any pending restarted system calls return -EINTR */
	current_thread_info()->restart_block.fn = do_no_restart_syscall;

#ifdef CONFIG_X86_32
	GET_SEG(gs);
	COPY_SEG(fs);
	COPY_SEG(es);
	COPY_SEG(ds);
#endif /* CONFIG_X86_32 */

	COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
	COPY(dx); COPY(cx); COPY(ip);

#ifdef CONFIG_X86_64
	COPY(r8);
	COPY(r9);
	COPY(r10);
	COPY(r11);
	COPY(r12);
	COPY(r13);
	COPY(r14);
	COPY(r15);
#endif /* CONFIG_X86_64 */

#ifdef CONFIG_X86_32
	COPY_SEG_CPL3(cs);
	COPY_SEG_CPL3(ss);
#else /* !CONFIG_X86_32 */
	/* Kernel saves and restores only the CS segment register on signals,
	 * which is the bare minimum needed to allow mixed 32/64-bit code.
	 * App's signal handler can save/restore other segments if needed. */
	COPY_SEG_CPL3(cs);
#endif /* CONFIG_X86_32 */

	err |= __get_user(tmpflags, &sc->flags);
	regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
	regs->orig_ax = -1;		/* disable syscall checks */

	err |= __get_user(buf, &sc->fpstate);
	err |= restore_i387_xstate(buf);

	err |= __get_user(*pax, &sc->ax);
	return err;
}

static int
setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
		 struct pt_regs *regs, unsigned long mask)
{
	int err = 0;

#ifdef CONFIG_X86_32
	{
		unsigned int tmp;

		savesegment(gs, tmp);
		err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
	}
	err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs);
	err |= __put_user(regs->es, (unsigned int __user *)&sc->es);
	err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds);
#endif /* CONFIG_X86_32 */

	err |= __put_user(regs->di, &sc->di);
	err |= __put_user(regs->si, &sc->si);
	err |= __put_user(regs->bp, &sc->bp);
	err |= __put_user(regs->sp, &sc->sp);
	err |= __put_user(regs->bx, &sc->bx);
	err |= __put_user(regs->dx, &sc->dx);
	err |= __put_user(regs->cx, &sc->cx);
	err |= __put_user(regs->ax, &sc->ax);
#ifdef CONFIG_X86_64
	err |= __put_user(regs->r8, &sc->r8);
	err |= __put_user(regs->r9, &sc->r9);
	err |= __put_user(regs->r10, &sc->r10);
	err |= __put_user(regs->r11, &sc->r11);
	err |= __put_user(regs->r12, &sc->r12);
	err |= __put_user(regs->r13, &sc->r13);
	err |= __put_user(regs->r14, &sc->r14);
	err |= __put_user(regs->r15, &sc->r15);
#endif /* CONFIG_X86_64 */

	err |= __put_user(current->thread.trap_no, &sc->trapno);
	err |= __put_user(current->thread.error_code, &sc->err);
	err |= __put_user(regs->ip, &sc->ip);
#ifdef CONFIG_X86_32
	err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs);
	err |= __put_user(regs->flags, &sc->flags);
	err |= __put_user(regs->sp, &sc->sp_at_signal);
	err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss);
#else /* !CONFIG_X86_32 */
	err |= __put_user(regs->flags, &sc->flags);
	err |= __put_user(regs->cs, &sc->cs);
	err |= __put_user(0, &sc->gs);
	err |= __put_user(0, &sc->fs);
#endif /* CONFIG_X86_32 */

	err |= __put_user(fpstate, &sc->fpstate);

	/* non-iBCS2 extensions.. */
	err |= __put_user(mask, &sc->oldmask);
	err |= __put_user(current->thread.cr2, &sc->cr2);

	return err;
}

/*
 * Set up a signal frame.
 */
#ifdef CONFIG_X86_32
static const struct {
	u16 poplmovl;
	u32 val;
	u16 int80;
} __attribute__((packed)) retcode = {
	0xb858,		/* popl %eax; movl $..., %eax */
	__NR_sigreturn,
	0x80cd,		/* int $0x80 */
};

static const struct {
	u8  movl;
	u32 val;
	u16 int80;
	u8  pad;
} __attribute__((packed)) rt_retcode = {
	0xb8,		/* movl $..., %eax */
	__NR_rt_sigreturn,
	0x80cd,		/* int $0x80 */
	0
};

/*
 * Determine which stack to use..
 */
static inline void __user *
get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
	     void **fpstate)
{
	unsigned long sp;

	/* Default to using normal stack */
	sp = regs->sp;

	/*
	 * If we are on the alternate signal stack and would overflow it, don't.
	 * Return an always-bogus address instead so we will die with SIGSEGV.
	 */
	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
		return (void __user *) -1L;

	/* This is the X/Open sanctioned signal stack switching.  */
	if (ka->sa.sa_flags & SA_ONSTACK) {
		if (sas_ss_flags(sp) == 0)
			sp = current->sas_ss_sp + current->sas_ss_size;
	} else {
		/* This is the legacy signal stack switching. */
		if ((regs->ss & 0xffff) != __USER_DS &&
			!(ka->sa.sa_flags & SA_RESTORER) &&
				ka->sa.sa_restorer)
			sp = (unsigned long) ka->sa.sa_restorer;
	}

	if (used_math()) {
		sp = sp - sig_xstate_size;
		*fpstate = (struct _fpstate *) sp;
		if (save_i387_xstate(*fpstate) < 0)
			return (void __user *)-1L;
	}

	sp -= frame_size;
	/*
	 * Align the stack pointer according to the i386 ABI,
	 * i.e. so that on function entry ((sp + 4) & 15) == 0.
	 */
	sp = ((sp + 4) & -16ul) - 4;

	return (void __user *) sp;
}

static int
__setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
	      struct pt_regs *regs)
{
	struct sigframe __user *frame;
	void __user *restorer;
	int err = 0;
	void __user *fpstate = NULL;

	frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		return -EFAULT;

	if (__put_user(sig, &frame->sig))
		return -EFAULT;

	if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
		return -EFAULT;

	if (_NSIG_WORDS > 1) {
		if (__copy_to_user(&frame->extramask, &set->sig[1],
				   sizeof(frame->extramask)))
			return -EFAULT;
	}

	if (current->mm->context.vdso)
		restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
	else
		restorer = &frame->retcode;
	if (ka->sa.sa_flags & SA_RESTORER)
		restorer = ka->sa.sa_restorer;

	/* Set up to return from userspace.  */
	err |= __put_user(restorer, &frame->pretcode);

	/*
	 * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
	 *
	 * WE DO NOT USE IT ANY MORE! It's only left here for historical
	 * reasons and because gdb uses it as a signature to notice
	 * signal handler stack frames.
	 */
	err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode);

	if (err)
		return -EFAULT;

	/* Set up registers for signal handler */
	regs->sp = (unsigned long)frame;
	regs->ip = (unsigned long)ka->sa.sa_handler;
	regs->ax = (unsigned long)sig;
	regs->dx = 0;
	regs->cx = 0;

	regs->ds = __USER_DS;
	regs->es = __USER_DS;
	regs->ss = __USER_DS;
	regs->cs = __USER_CS;

	return 0;
}

static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
			    sigset_t *set, struct pt_regs *regs)
{
	struct rt_sigframe __user *frame;
	void __user *restorer;
	int err = 0;
	void __user *fpstate = NULL;

	frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		return -EFAULT;

	err |= __put_user(sig, &frame->sig);
	err |= __put_user(&frame->info, &frame->pinfo);
	err |= __put_user(&frame->uc, &frame->puc);
	err |= copy_siginfo_to_user(&frame->info, info);
	if (err)
		return -EFAULT;

	/* Create the ucontext.  */
	if (cpu_has_xsave)
		err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
	else
		err |= __put_user(0, &frame->uc.uc_flags);
	err |= __put_user(0, &frame->uc.uc_link);
	err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
	err |= __put_user(sas_ss_flags(regs->sp),
			  &frame->uc.uc_stack.ss_flags);
	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
				regs, set->sig[0]);
	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	if (err)
		return -EFAULT;

	/* Set up to return from userspace.  */
	restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
	if (ka->sa.sa_flags & SA_RESTORER)
		restorer = ka->sa.sa_restorer;
	err |= __put_user(restorer, &frame->pretcode);