9c6f92408c
module->pathname.ko. It supports only ELF for now. Submitted by: bp (with some minor tweaks)
377 lines
8.7 KiB
C
377 lines
8.7 KiB
C
/*
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* Copyright (c) 2000, Boris Popov
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by Boris Popov.
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* 4. Neither the name of the author nor the names of any co-contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/exec.h>
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#include <sys/queue.h>
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#include <sys/kernel.h>
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#include <sys/reboot.h>
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#include <sys/linker.h>
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#include <string.h>
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#include <machine/bootinfo.h>
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#include <machine/elf.h>
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#include <stand.h>
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#define FREEBSD_ELF
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#include <link.h>
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#include <err.h>
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#include "ef.h"
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void
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ef_print_phdr(Elf_Phdr *phdr)
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{
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if ((phdr->p_flags & PF_W) == 0) {
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printf("text=0x%lx ", (long)phdr->p_filesz);
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} else {
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printf("data=0x%lx", (long)phdr->p_filesz);
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if (phdr->p_filesz < phdr->p_memsz)
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printf("+0x%lx", (long)(phdr->p_memsz - phdr->p_filesz));
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printf(" ");
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}
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}
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u_long
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ef_get_offset(elf_file_t ef, Elf_Off off)
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{
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Elf_Phdr *ph;
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int i;
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for (i = 0; i < ef->ef_nsegs; i++) {
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ph = ef->ef_segs[i];
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if (off >= ph->p_vaddr && off < ph->p_vaddr + ph->p_memsz) {
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return ph->p_offset + (off - ph->p_vaddr);
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}
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}
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return 0;
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}
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/*
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* next three functions copied from link_elf.c
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*/
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static unsigned long
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elf_hash(const char *name)
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{
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const unsigned char *p = (const unsigned char *) name;
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unsigned long h = 0;
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unsigned long g;
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while (*p != '\0') {
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h = (h << 4) + *p++;
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if ((g = h & 0xf0000000) != 0)
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h ^= g >> 24;
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h &= ~g;
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}
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return h;
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}
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int
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ef_lookup_symbol(elf_file_t ef, const char* name, Elf_Sym** sym)
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{
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unsigned long symnum;
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Elf_Sym* symp;
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char *strp;
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unsigned long hash;
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/* First, search hashed global symbols */
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hash = elf_hash(name);
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symnum = ef->ef_buckets[hash % ef->ef_nbuckets];
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while (symnum != STN_UNDEF) {
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if (symnum >= ef->ef_nchains) {
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warnx("ef_lookup_symbol: file %s have corrupted symbol table\n",
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ef->ef_name);
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return ENOENT;
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}
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symp = ef->ef_symtab + symnum;
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if (symp->st_name == 0) {
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warnx("ef_lookup_symbol: file %s have corrupted symbol table\n",
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ef->ef_name);
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return ENOENT;
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}
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strp = ef->ef_strtab + symp->st_name;
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if (strcmp(name, strp) == 0) {
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if (symp->st_shndx != SHN_UNDEF ||
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(symp->st_value != 0 &&
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ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
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*sym = symp;
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return 0;
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} else
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return ENOENT;
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}
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symnum = ef->ef_chains[symnum];
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}
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return ENOENT;
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}
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int
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ef_parse_dynamic(elf_file_t ef)
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{
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Elf_Dyn *dp;
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Elf_Off hashhdr[2];
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/* int plttype = DT_REL;*/
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int error;
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for (dp = ef->ef_dyn; dp->d_tag != DT_NULL; dp++) {
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switch (dp->d_tag) {
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case DT_HASH:
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error = ef_read(ef, ef_get_offset(ef, dp->d_un.d_ptr),
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sizeof(hashhdr), hashhdr);
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if (error) {
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warnx("can't read hash header (%lx)",
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ef_get_offset(ef, dp->d_un.d_ptr));
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return error;
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}
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ef->ef_nbuckets = hashhdr[0];
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ef->ef_nchains = hashhdr[1];
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error = ef_read_entry(ef, -1,
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(hashhdr[0] + hashhdr[1]) * sizeof(Elf_Off),
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(void**)&ef->ef_hashtab);
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if (error) {
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warnx("can't read hash table");
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return error;
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}
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ef->ef_buckets = ef->ef_hashtab;
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ef->ef_chains = ef->ef_buckets + ef->ef_nbuckets;
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break;
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case DT_STRTAB:
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ef->ef_stroff = dp->d_un.d_ptr;
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break;
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case DT_STRSZ:
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ef->ef_strsz = dp->d_un.d_val;
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break;
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case DT_SYMTAB:
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ef->ef_symoff = dp->d_un.d_ptr;
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break;
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case DT_SYMENT:
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if (dp->d_un.d_val != sizeof(Elf_Sym))
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return EFTYPE;
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break;
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}
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}
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if (ef->ef_symoff == 0) {
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warnx("%s: no .dynsym section found\n", ef->ef_name);
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return EFTYPE;
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}
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if (ef->ef_stroff == 0) {
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warnx("%s: no .dynstr section found\n", ef->ef_name);
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return EFTYPE;
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}
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if (ef_read_entry(ef, ef_get_offset(ef, ef->ef_symoff),
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ef->ef_nchains * sizeof(Elf_Sym),
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(void**)&ef->ef_symtab) != 0) {
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if (ef->ef_verbose)
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warnx("%s: can't load .dynsym section (0x%lx)",
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ef->ef_name, (long)ef->ef_symoff);
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return EIO;
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}
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if (ef_read_entry(ef, ef_get_offset(ef, ef->ef_stroff), ef->ef_strsz,
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(void**)&ef->ef_strtab) != 0) {
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warnx("can't load .dynstr section");
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return EIO;
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}
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return 0;
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}
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int
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ef_read(elf_file_t ef, Elf_Off offset, size_t len, void*dest)
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{
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if (offset != -1) {
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if (lseek(ef->ef_fd, offset, SEEK_SET) == -1)
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return EIO;
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}
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return read(ef->ef_fd, dest, len) == len ? 0 : EIO;
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}
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int
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ef_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void**ptr)
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{
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int error;
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*ptr = malloc(len);
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if (*ptr == NULL)
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return ENOMEM;
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error = ef_read(ef, offset, len, *ptr);
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if (error)
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free(*ptr);
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return error;
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}
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int
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ef_seg_read(elf_file_t ef, Elf_Off offset, size_t len, void*dest)
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{
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u_long ofs = ef_get_offset(ef, offset);
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if (ofs == 0) {
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if (ef->ef_verbose)
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warnx("ef_seg_read(%s): zero offset (%lx:%ld)",
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ef->ef_name, (long)offset, ofs);
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return EFAULT;
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}
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return ef_read(ef, ofs, len, dest);
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}
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int
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ef_seg_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void**ptr)
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{
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int error;
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*ptr = malloc(len);
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if (*ptr == NULL)
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return ENOMEM;
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error = ef_seg_read(ef, offset, len, *ptr);
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if (error)
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free(*ptr);
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return error;
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}
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int
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ef_open(const char *filename, elf_file_t ef, int verbose)
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{
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Elf_Ehdr *hdr;
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int fd;
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int error;
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int phlen, res;
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int nsegs;
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Elf_Phdr *phdr, *phdyn, *phphdr, *phlimit;
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bzero(ef, sizeof(*ef));
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if (filename == NULL)
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return EFTYPE;
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ef->ef_verbose = verbose;
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if ((fd = open(filename, O_RDONLY)) == -1)
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return errno;
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ef->ef_fd = fd;
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ef->ef_name = strdup(filename);
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hdr = (Elf_Ehdr *)&ef->ef_hdr;
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do {
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res = read(fd, hdr, sizeof(*hdr));
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error = EFTYPE;
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if (res != sizeof(*hdr))
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break;
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if (!IS_ELF(*hdr))
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break;
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if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
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hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
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hdr->e_ident[EI_VERSION] != EV_CURRENT ||
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hdr->e_version != EV_CURRENT ||
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hdr->e_machine != ELF_TARG_MACH ||
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hdr->e_phentsize != sizeof(Elf_Phdr))
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break;
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phlen = hdr->e_phnum * sizeof(Elf_Phdr);
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if (ef_read_entry(ef, hdr->e_phoff, phlen,
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(void**)&ef->ef_ph) != 0)
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break;
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phdr = ef->ef_ph;
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phlimit = phdr + hdr->e_phnum;
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nsegs = 0;
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phdyn = NULL;
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phphdr = NULL;
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while (phdr < phlimit) {
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if (verbose > 1)
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ef_print_phdr(phdr);
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switch (phdr->p_type) {
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case PT_LOAD:
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if (nsegs == 2) {
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warnx("%s: too many sections",
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filename);
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break;
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}
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ef->ef_segs[nsegs++] = phdr;
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break;
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case PT_PHDR:
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phphdr = phdr;
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break;
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case PT_DYNAMIC:
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phdyn = phdr;
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break;
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}
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phdr++;
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}
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if (verbose > 1)
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printf("\n");
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ef->ef_nsegs = nsegs;
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if (phdyn == NULL) {
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warnx("file isn't dynamically-linked");
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break;
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}
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if (ef_read_entry(ef, phdyn->p_offset,
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phdyn->p_filesz, (void**)&ef->ef_dyn) != 0) {
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printf("ef_read_entry failed\n");
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break;
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}
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error = ef_parse_dynamic(ef);
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if (error)
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break;
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if (hdr->e_type == ET_DYN) {
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ef->ef_type = EFT_KLD;
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/* pad = (u_int)dest & PAGE_MASK;
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if (pad)
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dest += PAGE_SIZE - pad;*/
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error = 0;
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} else if (hdr->e_type == ET_EXEC) {
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/* dest = hdr->e_entry;
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if (dest == 0)
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break;*/
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ef->ef_type = EFT_KERNEL;
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error = 0;
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} else
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break;
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} while(0);
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if (error) {
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ef_close(ef);
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if (ef->ef_verbose)
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warnc(error, "elf_open(%s)", filename);
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}
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return error;
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}
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int
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ef_close(elf_file_t ef)
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{
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close(ef->ef_fd);
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/* if (ef->ef_fpage)
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free(ef->ef_fpage);*/
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if (ef->ef_name)
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free(ef->ef_name);
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return 0;
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}
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