diff options
Diffstat (limited to 'linkers/elftoolchain/libelf/libelf_ehdr.c')
| -rw-r--r-- | linkers/elftoolchain/libelf/libelf_ehdr.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/linkers/elftoolchain/libelf/libelf_ehdr.c b/linkers/elftoolchain/libelf/libelf_ehdr.c new file mode 100644 index 0000000..affe541 --- /dev/null +++ b/linkers/elftoolchain/libelf/libelf_ehdr.c @@ -0,0 +1,204 @@ +/*- + * Copyright (c) 2006,2008 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 <assert.h> +#include <gelf.h> +#include <libelf.h> +#include <stdlib.h> + +#include "_libelf.h" + +LIBELF_VCSID("$Id: libelf_ehdr.c 1677 2011-07-28 04:35:53Z jkoshy $"); + +/* + * Retrieve counts for sections, phdrs and the section string table index + * from section header #0 of the ELF object. + */ +static int +_libelf_load_extended(Elf *e, int ec, uint64_t shoff, uint16_t phnum, + uint16_t strndx) +{ + Elf_Scn *scn; + size_t fsz; + int (*xlator)(char *_d, size_t _dsz, char *_s, size_t _c, int _swap); + uint32_t shtype; + + assert(STAILQ_EMPTY(&e->e_u.e_elf.e_scn)); + + fsz = _libelf_fsize(ELF_T_SHDR, ec, e->e_version, 1); + assert(fsz > 0); + + if (e->e_rawsize < shoff + fsz) { /* raw file too small */ + LIBELF_SET_ERROR(HEADER, 0); + return (0); + } + + if ((scn = _libelf_allocate_scn(e, (size_t) 0)) == NULL) + return (0); + + xlator = _libelf_get_translator(ELF_T_SHDR, ELF_TOMEMORY, ec); + (*xlator)((char *) &scn->s_shdr, sizeof(scn->s_shdr), + e->e_rawfile + shoff, (size_t) 1, + e->e_byteorder != LIBELF_PRIVATE(byteorder)); + +#define GET_SHDR_MEMBER(M) ((ec == ELFCLASS32) ? scn->s_shdr.s_shdr32.M : \ + scn->s_shdr.s_shdr64.M) + + if ((shtype = GET_SHDR_MEMBER(sh_type)) != SHT_NULL) { + LIBELF_SET_ERROR(SECTION, 0); + return (0); + } + + e->e_u.e_elf.e_nscn = GET_SHDR_MEMBER(sh_size); + e->e_u.e_elf.e_nphdr = (phnum != PN_XNUM) ? phnum : + GET_SHDR_MEMBER(sh_info); + e->e_u.e_elf.e_strndx = (strndx != SHN_XINDEX) ? strndx : + GET_SHDR_MEMBER(sh_link); +#undef GET_SHDR_MEMBER + + return (1); +} + +#define EHDR_INIT(E,SZ) do { \ + Elf##SZ##_Ehdr *eh = (E); \ + eh->e_ident[EI_MAG0] = ELFMAG0; \ + eh->e_ident[EI_MAG1] = ELFMAG1; \ + eh->e_ident[EI_MAG2] = ELFMAG2; \ + eh->e_ident[EI_MAG3] = ELFMAG3; \ + eh->e_ident[EI_CLASS] = ELFCLASS##SZ; \ + eh->e_ident[EI_DATA] = ELFDATANONE; \ + eh->e_ident[EI_VERSION] = LIBELF_PRIVATE(version); \ + eh->e_machine = EM_NONE; \ + eh->e_type = ELF_K_NONE; \ + eh->e_version = LIBELF_PRIVATE(version); \ + } while (0) + +void * +_libelf_ehdr(Elf *e, int ec, int allocate) +{ + void *ehdr; + size_t fsz, msz; + uint16_t phnum, shnum, strndx; + uint64_t shoff; + int (*xlator)(char *_d, size_t _dsz, char *_s, size_t _c, int _swap); + + assert(ec == ELFCLASS32 || ec == ELFCLASS64); + + if (e == NULL || e->e_kind != ELF_K_ELF) { + LIBELF_SET_ERROR(ARGUMENT, 0); + return (NULL); + } + + if (e->e_class != ELFCLASSNONE && e->e_class != ec) { + LIBELF_SET_ERROR(CLASS, 0); + return (NULL); + } + + if (e->e_version != EV_CURRENT) { + LIBELF_SET_ERROR(VERSION, 0); + return (NULL); + } + + if (e->e_class == ELFCLASSNONE) + e->e_class = ec; + + if (ec == ELFCLASS32) + ehdr = (void *) e->e_u.e_elf.e_ehdr.e_ehdr32; + else + ehdr = (void *) e->e_u.e_elf.e_ehdr.e_ehdr64; + + if (ehdr != NULL) /* already have a translated ehdr */ + return (ehdr); + + fsz = _libelf_fsize(ELF_T_EHDR, ec, e->e_version, (size_t) 1); + assert(fsz > 0); + + if (e->e_cmd != ELF_C_WRITE && e->e_rawsize < fsz) { + LIBELF_SET_ERROR(HEADER, 0); + return (NULL); + } + + msz = _libelf_msize(ELF_T_EHDR, ec, EV_CURRENT); + + assert(msz > 0); + + if ((ehdr = calloc((size_t) 1, msz)) == NULL) { + LIBELF_SET_ERROR(RESOURCE, 0); + return (NULL); + } + + if (ec == ELFCLASS32) { + e->e_u.e_elf.e_ehdr.e_ehdr32 = ehdr; + EHDR_INIT(ehdr,32); + } else { + e->e_u.e_elf.e_ehdr.e_ehdr64 = ehdr; + EHDR_INIT(ehdr,64); + } + + if (allocate) + e->e_flags |= ELF_F_DIRTY; + + if (e->e_cmd == ELF_C_WRITE) + return (ehdr); + + xlator = _libelf_get_translator(ELF_T_EHDR, ELF_TOMEMORY, ec); + (*xlator)(ehdr, msz, e->e_rawfile, (size_t) 1, + e->e_byteorder != LIBELF_PRIVATE(byteorder)); + + /* + * If extended numbering is being used, read the correct + * number of sections and program header entries. + */ + if (ec == ELFCLASS32) { + phnum = ((Elf32_Ehdr *) ehdr)->e_phnum; + shnum = ((Elf32_Ehdr *) ehdr)->e_shnum; + shoff = ((Elf32_Ehdr *) ehdr)->e_shoff; + strndx = ((Elf32_Ehdr *) ehdr)->e_shstrndx; + } else { + phnum = ((Elf64_Ehdr *) ehdr)->e_phnum; + shnum = ((Elf64_Ehdr *) ehdr)->e_shnum; + shoff = ((Elf64_Ehdr *) ehdr)->e_shoff; + strndx = ((Elf64_Ehdr *) ehdr)->e_shstrndx; + } + + if (shnum >= SHN_LORESERVE || + (shoff == 0LL && (shnum != 0 || phnum == PN_XNUM || + strndx == SHN_XINDEX))) { + LIBELF_SET_ERROR(HEADER, 0); + return (NULL); + } + + if (shnum != 0 || shoff == 0LL) { /* not using extended numbering */ + e->e_u.e_elf.e_nphdr = phnum; + e->e_u.e_elf.e_nscn = shnum; + e->e_u.e_elf.e_strndx = strndx; + } else if (_libelf_load_extended(e, ec, shoff, phnum, strndx) == 0) + return (NULL); + + return (ehdr); +} |