518 lines
13 KiB
C
518 lines
13 KiB
C
/*-
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* Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
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* Copyright (c) 1998 Peter Wemm <peter@freebsd.org>
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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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*
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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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* $Id: load_elf.c,v 1.10 1999/01/04 18:37:41 peter Exp $
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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/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 "bootstrap.h"
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static int elf_loadimage(struct loaded_module *mp, int fd, vm_offset_t loadaddr, Elf_Ehdr *ehdr, int kernel, caddr_t firstpage, int firstlen);
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char *elf_kerneltype = "elf kernel";
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char *elf_moduletype = "elf module";
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/*
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* Attempt to load the file (file) as an ELF module. It will be stored at
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* (dest), and a pointer to a module structure describing the loaded object
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* will be saved in (result).
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*/
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int
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elf_loadmodule(char *filename, vm_offset_t dest, struct loaded_module **result)
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{
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struct loaded_module *mp, *kmp;
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Elf_Ehdr *ehdr;
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int fd;
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int err, kernel;
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u_int pad;
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char *s;
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caddr_t firstpage;
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int firstlen;
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mp = NULL;
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/*
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* Open the image, read and validate the ELF header
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*/
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if (filename == NULL) /* can't handle nameless */
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return(EFTYPE);
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if ((fd = open(filename, O_RDONLY)) == -1)
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return(errno);
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firstpage = malloc(PAGE_SIZE);
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if (firstpage == NULL)
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return(ENOMEM);
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firstlen = read(fd, firstpage, PAGE_SIZE);
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if (firstlen <= sizeof(ehdr)) {
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err = EFTYPE; /* could be EIO, but may be small file */
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goto oerr;
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}
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ehdr = (Elf_Ehdr *)firstpage;
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/* Is it ELF? */
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if (!IS_ELF(*ehdr)) {
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err = EFTYPE;
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goto oerr;
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}
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if (ehdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || /* Layout ? */
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ehdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
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ehdr->e_ident[EI_VERSION] != EV_CURRENT || /* Version ? */
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ehdr->e_version != EV_CURRENT ||
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ehdr->e_machine != ELF_TARG_MACH) { /* Machine ? */
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err = EFTYPE;
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goto oerr;
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}
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/*
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* Check to see what sort of module we are.
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*/
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kmp = mod_findmodule(NULL, NULL);
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if (ehdr->e_type == ET_DYN) {
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/* Looks like a kld module */
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if (kmp == NULL) {
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printf("elf_loadmodule: can't load module before kernel\n");
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err = EPERM;
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goto oerr;
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}
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if (strcmp(elf_kerneltype, kmp->m_type)) {
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printf("elf_loadmodule: can't load module with kernel type '%s'\n", kmp->m_type);
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err = EPERM;
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goto oerr;
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}
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/* Looks OK, got ahead */
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kernel = 0;
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/* Page-align the load address */
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pad = (u_int)dest & PAGE_MASK;
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if (pad != 0) {
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pad = PAGE_SIZE - pad;
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dest += pad;
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}
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} else if (ehdr->e_type == ET_EXEC) {
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/* Looks like a kernel */
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if (kmp != NULL) {
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printf("elf_loadmodule: kernel already loaded\n");
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err = EPERM;
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goto oerr;
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}
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/*
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* Calculate destination address based on kernel entrypoint
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*/
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dest = (vm_offset_t) ehdr->e_entry;
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if (dest == 0) {
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printf("elf_loadmodule: not a kernel (maybe static binary?)\n");
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err = EPERM;
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goto oerr;
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}
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kernel = 1;
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} else {
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err = EFTYPE;
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goto oerr;
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}
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/*
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* Ok, we think we should handle this.
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*/
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mp = mod_allocmodule();
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if (mp == NULL) {
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printf("elf_loadmodule: cannot allocate module info\n");
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err = EPERM;
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goto out;
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}
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if (kernel)
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setenv("kernelname", filename, 1);
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s = strrchr(filename, '/');
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if (s)
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mp->m_name = strdup(s + 1);
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else
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mp->m_name = strdup(filename);
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mp->m_type = strdup(kernel ? elf_kerneltype : elf_moduletype);
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#ifdef ELF_VERBOSE
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if (kernel)
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printf("%s entry at %p\n", filename, (void *) dest);
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#else
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printf("%s ", filename);
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#endif
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mp->m_size = elf_loadimage(mp, fd, dest, ehdr, kernel, firstpage, firstlen);
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if (mp->m_size == 0 || mp->m_addr == 0)
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goto ioerr;
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/* save exec header as metadata */
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mod_addmetadata(mp, MODINFOMD_ELFHDR, sizeof(*ehdr), ehdr);
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/* Load OK, return module pointer */
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*result = (struct loaded_module *)mp;
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err = 0;
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goto out;
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ioerr:
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err = EIO;
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oerr:
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mod_discard(mp);
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out:
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if (firstpage)
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free(firstpage);
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close(fd);
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return(err);
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}
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/*
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* With the file (fd) open on the image, and (ehdr) containing
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* the Elf header, load the image at (off)
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*/
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static int
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elf_loadimage(struct loaded_module *mp, int fd, vm_offset_t off,
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Elf_Ehdr *ehdr, int kernel, caddr_t firstpage, int firstlen)
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{
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int i, j;
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Elf_Phdr *phdr;
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Elf_Shdr *shdr;
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int ret;
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vm_offset_t firstaddr;
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vm_offset_t lastaddr;
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void *buf;
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size_t resid, chunk;
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vm_offset_t dest;
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vm_offset_t ssym, esym;
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Elf_Dyn *dp;
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int ndp;
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int deplen;
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char *depdata;
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char *s;
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int len;
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char *strtab;
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size_t strsz;
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int symstrindex;
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int symtabindex;
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long size;
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int fpcopy;
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dp = NULL;
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shdr = NULL;
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ret = 0;
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firstaddr = lastaddr = 0;
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if (kernel) {
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#ifdef __i386__
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off = - (off & 0xff000000u); /* i386 relocates after locore */
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#else
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off = 0; /* alpha is direct mapped for kernels */
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#endif
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}
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if ((ehdr->e_phoff + ehdr->e_phnum * sizeof(*phdr)) > firstlen) {
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printf("elf_loadimage: program header not within first page\n");
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goto out;
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}
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phdr = (Elf_Phdr *)(firstpage + ehdr->e_phoff);
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for (i = 0; i < ehdr->e_phnum; i++) {
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/* We want to load PT_LOAD segments only.. */
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if (phdr[i].p_type != PT_LOAD)
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continue;
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#ifdef ELF_VERBOSE
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printf("Segment: 0x%lx@0x%lx -> 0x%lx-0x%lx",
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(long)phdr[i].p_filesz, (long)phdr[i].p_offset,
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(long)(phdr[i].p_vaddr + off),
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(long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1));
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#else
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if ((phdr[i].p_flags & PF_W) == 0) {
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printf("text=0x%lx ", (long)phdr[i].p_filesz);
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} else {
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printf("data=0x%lx", (long)phdr[i].p_filesz);
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if (phdr[i].p_filesz < phdr[i].p_memsz)
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printf("+0x%lx", (long)(phdr[i].p_memsz -phdr[i].p_filesz));
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printf(" ");
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}
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#endif
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fpcopy = 0;
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if (firstlen > phdr[i].p_offset) {
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fpcopy = firstlen - phdr[i].p_offset;
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archsw.arch_copyin(firstpage + phdr[i].p_offset,
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phdr[i].p_vaddr + off, fpcopy);
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}
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if (phdr[i].p_filesz > fpcopy) {
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if (lseek(fd, phdr[i].p_offset + fpcopy, SEEK_SET) == -1) {
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printf("\nelf_loadexec: cannot seek\n");
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goto out;
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}
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if (archsw.arch_readin(fd, phdr[i].p_vaddr + off + fpcopy,
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phdr[i].p_filesz - fpcopy) != phdr[i].p_filesz - fpcopy) {
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printf("\nelf_loadexec: archsw.readin failed\n");
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goto out;
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}
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}
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/* clear space from oversized segments; eg: bss */
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if (phdr[i].p_filesz < phdr[i].p_memsz) {
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#ifdef ELF_VERBOSE
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printf(" (bss: 0x%lx-0x%lx)",
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(long)(phdr[i].p_vaddr + off + phdr[i].p_filesz),
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(long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1));
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#endif
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/* no archsw.arch_bzero */
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buf = malloc(PAGE_SIZE);
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bzero(buf, PAGE_SIZE);
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resid = phdr[i].p_memsz - phdr[i].p_filesz;
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dest = phdr[i].p_vaddr + off + phdr[i].p_filesz;
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while (resid > 0) {
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chunk = min(PAGE_SIZE, resid);
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archsw.arch_copyin(buf, dest, chunk);
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resid -= chunk;
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dest += chunk;
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}
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free(buf);
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}
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#ifdef ELF_VERBOSE
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printf("\n");
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#endif
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if (firstaddr == 0 || firstaddr > (phdr[i].p_vaddr + off))
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firstaddr = phdr[i].p_vaddr + off;
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if (lastaddr == 0 || lastaddr < (phdr[i].p_vaddr + off + phdr[i].p_memsz))
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lastaddr = phdr[i].p_vaddr + off + phdr[i].p_memsz;
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}
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lastaddr = roundup(lastaddr, sizeof(long));
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/*
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* Now grab the symbol tables. This isn't easy if we're reading a
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* .gz file. I think the rule is going to have to be that you must
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* strip a file to remove symbols before gzipping it so that we do not
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* try to lseek() on it.
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*/
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chunk = ehdr->e_shnum * ehdr->e_shentsize;
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if (chunk == 0 || ehdr->e_shoff == 0)
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goto nosyms;
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shdr = malloc(chunk);
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if (shdr == NULL)
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goto nosyms;
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if (lseek(fd, ehdr->e_shoff, SEEK_SET) == -1) {
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printf("\nelf_loadimage: cannot lseek() to section headers");
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goto nosyms;
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}
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if (read(fd, shdr, chunk) != chunk) {
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printf("\nelf_loadimage: read section headers failed");
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goto nosyms;
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}
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symtabindex = -1;
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symstrindex = -1;
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for (i = 0; i < ehdr->e_shnum; i++) {
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if (shdr[i].sh_type != SHT_SYMTAB)
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continue;
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for (j = 0; j < ehdr->e_phnum; j++) {
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if (phdr[j].p_type != PT_LOAD)
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continue;
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if (shdr[i].sh_offset >= phdr[j].p_offset &&
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(shdr[i].sh_offset + shdr[i].sh_size <=
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phdr[j].p_offset + phdr[j].p_filesz)) {
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shdr[i].sh_offset = 0;
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shdr[i].sh_size = 0;
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break;
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}
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}
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if (shdr[i].sh_offset == 0 || shdr[i].sh_size == 0)
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continue; /* alread loaded in a PT_LOAD above */
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/* Save it for loading below */
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symtabindex = i;
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symstrindex = shdr[i].sh_link;
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}
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if (symtabindex < 0 || symstrindex < 0)
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goto nosyms;
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/* Ok, committed to a load. */
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#ifndef ELF_VERBOSE
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printf("syms=[");
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#endif
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ssym = lastaddr;
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for (i = symtabindex; i >= 0; i = symstrindex) {
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#ifdef ELF_VERBOSE
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char *secname;
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switch(shdr[i].sh_type) {
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case SHT_SYMTAB: /* Symbol table */
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secname = "symtab";
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break;
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case SHT_STRTAB: /* String table */
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secname = "strtab";
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break;
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default:
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secname = "WHOA!!";
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break;
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}
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#endif
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size = shdr[i].sh_size;
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archsw.arch_copyin(&size, lastaddr, sizeof(size));
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lastaddr += sizeof(long);
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#ifdef ELF_VERBOSE
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printf("\n%s: 0x%lx@0x%lx -> 0x%lx-0x%lx", secname,
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shdr[i].sh_size, shdr[i].sh_offset,
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lastaddr, lastaddr + shdr[i].sh_size);
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#else
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if (i == symstrindex)
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printf("+");
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printf("0x%lx+0x%lx", (long)sizeof(size), size);
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#endif
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if (lseek(fd, shdr[i].sh_offset, SEEK_SET) == -1) {
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printf("\nelf_loadimage: could not seek for symbols - skipped!");
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lastaddr = ssym;
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ssym = 0;
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goto nosyms;
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}
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if (archsw.arch_readin(fd, lastaddr, shdr[i].sh_size) !=
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shdr[i].sh_size) {
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printf("\nelf_loadimage: could not read symbols - skipped!");
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lastaddr = ssym;
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ssym = 0;
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goto nosyms;
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}
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/* Reset offsets relative to ssym */
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lastaddr += shdr[i].sh_size;
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lastaddr = roundup(lastaddr, sizeof(long));
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if (i == symtabindex)
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symtabindex = -1;
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else if (i == symstrindex)
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symstrindex = -1;
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}
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esym = lastaddr;
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#ifndef ELF_VERBOSE
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printf("]");
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#endif
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mod_addmetadata(mp, MODINFOMD_SSYM, sizeof(ssym), &ssym);
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mod_addmetadata(mp, MODINFOMD_ESYM, sizeof(esym), &esym);
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nosyms:
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printf("\n");
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ret = lastaddr - firstaddr;
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mp->m_addr = firstaddr;
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for (i = 0; i < ehdr->e_phnum; i++) {
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if (phdr[i].p_type == PT_DYNAMIC) {
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dp = (Elf_Dyn *)(phdr[i].p_vaddr);
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mod_addmetadata(mp, MODINFOMD_DYNAMIC, sizeof(dp), &dp);
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dp = NULL;
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break;
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}
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}
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if (kernel) /* kernel must not depend on anything */
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goto out;
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ndp = 0;
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for (i = 0; i < ehdr->e_phnum; i++) {
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if (phdr[i].p_type == PT_DYNAMIC) {
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ndp = phdr[i].p_filesz / sizeof(Elf_Dyn);
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dp = malloc(phdr[i].p_filesz);
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archsw.arch_copyout(phdr[i].p_vaddr + off, dp, phdr[i].p_filesz);
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}
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}
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if (dp == NULL || ndp == 0)
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goto out;
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strtab = NULL;
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strsz = 0;
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deplen = 0;
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for (i = 0; i < ndp; i++) {
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if (dp[i].d_tag == NULL)
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break;
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switch (dp[i].d_tag) {
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case DT_STRTAB:
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strtab = (char *)(dp[i].d_un.d_ptr + off);
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break;
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case DT_STRSZ:
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strsz = dp[i].d_un.d_val;
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break;
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default:
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break;
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}
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}
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if (strtab == NULL || strsz == 0)
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goto out;
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deplen = 0;
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for (i = 0; i < ndp; i++) {
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if (dp[i].d_tag == NULL)
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break;
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switch (dp[i].d_tag) {
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case DT_NEEDED: /* count size for dependency list */
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j = dp[i].d_un.d_ptr;
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if (j < 1 || j > (strsz - 2))
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continue; /* bad symbol name index */
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deplen += strlenout((vm_offset_t)&strtab[j]) + 1;
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break;
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default:
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break;
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}
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}
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if (deplen > 0) {
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depdata = malloc(deplen);
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if (depdata == NULL)
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goto out;
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s = depdata;
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for (i = 0; i < ndp; i++) {
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if (dp[i].d_tag == NULL)
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|
break;
|
|
switch (dp[i].d_tag) {
|
|
case DT_NEEDED: /* dependency list */
|
|
j = dp[i].d_un.d_ptr;
|
|
len = strlenout((vm_offset_t)&strtab[j]) + 1;
|
|
archsw.arch_copyout((vm_offset_t)&strtab[j], s, len);
|
|
s += len;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
if ((s - depdata) > 0)
|
|
mod_addmetadata(mp, MODINFOMD_DEPLIST, s - depdata, depdata);
|
|
free(depdata);
|
|
}
|
|
|
|
out:
|
|
if (dp)
|
|
free(dp);
|
|
if (shdr)
|
|
free(shdr);
|
|
return ret;
|
|
}
|