diff options
Diffstat (limited to 'linkers/elftoolchain/libelf/elf_scn.c')
| -rw-r--r-- | linkers/elftoolchain/libelf/elf_scn.c | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/linkers/elftoolchain/libelf/elf_scn.c b/linkers/elftoolchain/libelf/elf_scn.c new file mode 100644 index 0000000..80444fd --- /dev/null +++ b/linkers/elftoolchain/libelf/elf_scn.c @@ -0,0 +1,232 @@ +/*- + * Copyright (c) 2006,2008-2010 Joseph Koshy + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +#include <sys/queue.h> + +#include <assert.h> +#include <errno.h> +#include <gelf.h> +#include <libelf.h> +#include <stddef.h> +#include <stdlib.h> + +#include "_libelf.h" + +LIBELF_VCSID("$Id: elf_scn.c 1077 2010-08-09 15:37:40Z jkoshy $"); + +/* + * Load an ELF section table and create a list of Elf_Scn structures. + */ +int +_libelf_load_section_headers(Elf *e, void *ehdr) +{ + int ec, swapbytes; + size_t fsz, i, shnum; + uint64_t shoff; + char *src; + Elf32_Ehdr *eh32; + Elf64_Ehdr *eh64; + Elf_Scn *scn; + int (*xlator)(char *_d, size_t _dsz, char *_s, size_t _c, int _swap); + + assert(e != NULL); + assert(ehdr != NULL); + assert((e->e_flags & LIBELF_F_SHDRS_LOADED) == 0); + +#define CHECK_EHDR(E,EH) do { \ + if (fsz != (EH)->e_shentsize || \ + shoff + fsz * shnum > e->e_rawsize) { \ + LIBELF_SET_ERROR(HEADER, 0); \ + return (0); \ + } \ + } while (0) + + ec = e->e_class; + fsz = _libelf_fsize(ELF_T_SHDR, ec, e->e_version, (size_t) 1); + assert(fsz > 0); + + shnum = e->e_u.e_elf.e_nscn; + + if (ec == ELFCLASS32) { + eh32 = (Elf32_Ehdr *) ehdr; + shoff = (uint64_t) eh32->e_shoff; + CHECK_EHDR(e, eh32); + } else { + eh64 = (Elf64_Ehdr *) ehdr; + shoff = eh64->e_shoff; + CHECK_EHDR(e, eh64); + } + + xlator = _libelf_get_translator(ELF_T_SHDR, ELF_TOMEMORY, ec); + + swapbytes = e->e_byteorder != LIBELF_PRIVATE(byteorder); + src = e->e_rawfile + shoff; + + /* + * If the file is using extended numbering then section #0 + * would have already been read in. + */ + + i = 0; + if (!STAILQ_EMPTY(&e->e_u.e_elf.e_scn)) { + assert(STAILQ_FIRST(&e->e_u.e_elf.e_scn) == + STAILQ_LAST(&e->e_u.e_elf.e_scn, _Elf_Scn, s_next)); + + i = 1; + src += fsz; + } + + for (; i < shnum; i++, src += fsz) { + if ((scn = _libelf_allocate_scn(e, i)) == NULL) + return (0); + + (*xlator)((char *) &scn->s_shdr, sizeof(scn->s_shdr), src, + (size_t) 1, swapbytes); + + if (ec == ELFCLASS32) { + scn->s_offset = scn->s_rawoff = + scn->s_shdr.s_shdr32.sh_offset; + scn->s_size = scn->s_shdr.s_shdr32.sh_size; + } else { + scn->s_offset = scn->s_rawoff = + scn->s_shdr.s_shdr64.sh_offset; + scn->s_size = scn->s_shdr.s_shdr64.sh_size; + } + } + + e->e_flags |= LIBELF_F_SHDRS_LOADED; + + return (1); +} + + +Elf_Scn * +elf_getscn(Elf *e, size_t index) +{ + int ec; + void *ehdr; + Elf_Scn *s; + + if (e == NULL || e->e_kind != ELF_K_ELF || + ((ec = e->e_class) != ELFCLASS32 && ec != ELFCLASS64)) { + LIBELF_SET_ERROR(ARGUMENT, 0); + return (NULL); + } + + if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) + return (NULL); + + if (e->e_cmd != ELF_C_WRITE && + (e->e_flags & LIBELF_F_SHDRS_LOADED) == 0 && + _libelf_load_section_headers(e, ehdr) == 0) + return (NULL); + + STAILQ_FOREACH(s, &e->e_u.e_elf.e_scn, s_next) + if (s->s_ndx == index) + return (s); + + LIBELF_SET_ERROR(ARGUMENT, 0); + return (NULL); +} + +size_t +elf_ndxscn(Elf_Scn *s) +{ + if (s == NULL) { + LIBELF_SET_ERROR(ARGUMENT, 0); + return (SHN_UNDEF); + } + return (s->s_ndx); +} + +Elf_Scn * +elf_newscn(Elf *e) +{ + int ec; + void *ehdr; + Elf_Scn *scn; + + if (e == NULL || e->e_kind != ELF_K_ELF) { + LIBELF_SET_ERROR(ARGUMENT, 0); + return (NULL); + } + + if ((ec = e->e_class) != ELFCLASS32 && ec != ELFCLASS64) { + LIBELF_SET_ERROR(CLASS, 0); + return (NULL); + } + + if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) + return (NULL); + + /* + * The application may be asking for a new section descriptor + * on an ELF object opened with ELF_C_RDWR or ELF_C_READ. We + * need to bring in the existing section information before + * appending a new one to the list. + * + * Per the ELF(3) API, an application is allowed to open a + * file using ELF_C_READ, mess with its internal structure and + * use elf_update(...,ELF_C_NULL) to compute its new layout. + */ + if (e->e_cmd != ELF_C_WRITE && + (e->e_flags & LIBELF_F_SHDRS_LOADED) == 0 && + _libelf_load_section_headers(e, ehdr) == 0) + return (NULL); + + if (STAILQ_EMPTY(&e->e_u.e_elf.e_scn)) { + assert(e->e_u.e_elf.e_nscn == 0); + if ((scn = _libelf_allocate_scn(e, (size_t) SHN_UNDEF)) == + NULL) + return (NULL); + e->e_u.e_elf.e_nscn++; + } + + assert(e->e_u.e_elf.e_nscn > 0); + + if ((scn = _libelf_allocate_scn(e, e->e_u.e_elf.e_nscn)) == NULL) + return (NULL); + + e->e_u.e_elf.e_nscn++; + + (void) elf_flagscn(scn, ELF_C_SET, ELF_F_DIRTY); + + return (scn); +} + +Elf_Scn * +elf_nextscn(Elf *e, Elf_Scn *s) +{ + if (e == NULL || (e->e_kind != ELF_K_ELF) || + (s && s->s_elf != e)) { + LIBELF_SET_ERROR(ARGUMENT, 0); + return (NULL); + } + + return (s == NULL ? elf_getscn(e, (size_t) 1) : + STAILQ_NEXT(s, s_next)); +} |