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author | jkoshy <jkoshy@FreeBSD.org> | 2006-11-11 17:16:35 +0000 |
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committer | jkoshy <jkoshy@FreeBSD.org> | 2006-11-11 17:16:35 +0000 |
commit | 62913629e64cdad23072cfd4ad8340f4c0b91ec5 (patch) | |
tree | c2ad604787a38d6ad26a0bffea71f283f73e901d /lib/libelf/elf_scn.c | |
parent | c51a2c2df9d95524e4fec5b0ec36ca0a9f503823 (diff) | |
download | FreeBSD-src-62913629e64cdad23072cfd4ad8340f4c0b91ec5.zip FreeBSD-src-62913629e64cdad23072cfd4ad8340f4c0b91ec5.tar.gz |
MFP4: Add an implementation of the ELF(3) and GELF(3) API set.
Bump __FreeBSD_version.
Reviewed by: jb
Diffstat (limited to 'lib/libelf/elf_scn.c')
-rw-r--r-- | lib/libelf/elf_scn.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/lib/libelf/elf_scn.c b/lib/libelf/elf_scn.c new file mode 100644 index 0000000..fa1527f --- /dev/null +++ b/lib/libelf/elf_scn.c @@ -0,0 +1,244 @@ +/*- + * Copyright (c) 2006 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> +__FBSDID("$FreeBSD$"); + +#include <assert.h> +#include <errno.h> +#include <gelf.h> +#include <libelf.h> +#include <stdlib.h> + +#include "_libelf.h" + +/* + * Load an ELF section table and create a list of Elf_Scn structures. + */ +static int +_libelf_load_scn(Elf *e, void *ehdr) +{ + int ec, swapbytes; + size_t fsz, i, shnum; + uint64_t shoff; + uint32_t shtype; + char *src; + Elf32_Ehdr *eh32; + Elf64_Ehdr *eh64; + Elf_Scn *scn; + void (*xlator)(char *_d, char *_s, size_t _c, int _swap); + + assert(e != NULL); + assert(ehdr != NULL); + +#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) + + fsz = gelf_fsize(e, ELF_T_SHDR, (size_t) 1, e->e_version); + assert(fsz > 0); + + ec = e->e_class; + if (ec == ELFCLASS32) { + eh32 = (Elf32_Ehdr *) ehdr; + shnum = eh32->e_shnum; + shoff = (uint64_t) eh32->e_shoff; + CHECK_EHDR(e, eh32); + } else { + eh64 = (Elf64_Ehdr *) ehdr; + shnum = eh64->e_shnum; + 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; + i = 0; + + if (shnum == (size_t) 0 && shoff != 0LL) { + /* Extended section numbering */ + if ((scn = _libelf_allocate_scn(e, (size_t) 0)) == NULL) + return (0); + + (*xlator)((char *) &scn->s_shdr, src, (size_t) 1, swapbytes); + + if (ec == ELFCLASS32) { + shtype = scn->s_shdr.s_shdr32.sh_type; + shnum = scn->s_shdr.s_shdr32.sh_size; + } else { + shtype = scn->s_shdr.s_shdr64.sh_type; + shnum = scn->s_shdr.s_shdr64.sh_size; + } + + if (shtype != SHT_NULL) { + LIBELF_SET_ERROR(SECTION, 0); + return (0); + } + + scn->s_size = 0LL; + scn->s_offset = scn->s_rawoff = 0LL; + + i++; + src += fsz; + } + + for (; i < shnum; i++, src += fsz) { + if ((scn = _libelf_allocate_scn(e, i)) == NULL) + return (0); + + (*xlator)((char *) &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; + } + } + 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 && STAILQ_EMPTY(&e->e_u.e_elf.e_scn) && + _libelf_load_scn(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; + size_t shnum; + 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 && STAILQ_EMPTY(&e->e_u.e_elf.e_scn) && + _libelf_load_scn(e, ehdr) == 0) + return (NULL); + + if (_libelf_getshnum(e, ehdr, ec, &shnum) == 0) + return (NULL); + + if (STAILQ_EMPTY(&e->e_u.e_elf.e_scn)) { + assert(shnum == 0); + if ((scn = _libelf_allocate_scn(e, (size_t) SHN_UNDEF)) == + NULL) + return (NULL); + shnum++; + } + + assert(shnum > 0); + + if ((scn = _libelf_allocate_scn(e, shnum)) == NULL) + return (NULL); + + shnum++; + + if (_libelf_setshnum(e, ehdr, ec, shnum) == 0) + return (NULL); + + (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)); +} |