mirror of
https://git.FreeBSD.org/src.git
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5e6220d9d0
longer includes machine/elf.h. * consumers of elf.h now use the minimalist elf header possible. This change is motivated by Binutils 2.11.0 and too much clashing over our base elf headers and the Binutils elf headers.
417 lines
11 KiB
C
417 lines
11 KiB
C
/*
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* Copyright (c) 1989, 1993
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* The Regents of the University of California. 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 the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its 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 REGENTS 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 REGENTS 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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#if defined(LIBC_SCCS) && !defined(lint)
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static char sccsid[] = "@(#)nlist.c 8.1 (Berkeley) 6/4/93";
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#endif /* LIBC_SCCS and not lint */
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#include "namespace.h"
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#include <sys/param.h>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <sys/file.h>
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#include <errno.h>
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#include <a.out.h>
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#include <stdio.h>
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#include <string.h>
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#include <unistd.h>
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#include "un-namespace.h"
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#define _NLIST_DO_AOUT
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#define _NLIST_DO_ELF
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#ifdef _NLIST_DO_ELF
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#include <machine/elf.h>
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#include <elf-hints.h>
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#endif
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int __fdnlist __P((int, struct nlist *));
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int __aout_fdnlist __P((int, struct nlist *));
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int __elf_fdnlist __P((int, struct nlist *));
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int
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nlist(name, list)
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const char *name;
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struct nlist *list;
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{
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int fd, n;
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fd = _open(name, O_RDONLY, 0);
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if (fd < 0)
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return (-1);
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n = __fdnlist(fd, list);
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(void)_close(fd);
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return (n);
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}
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static struct nlist_handlers {
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int (*fn) __P((int fd, struct nlist *list));
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} nlist_fn[] = {
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#ifdef _NLIST_DO_AOUT
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{ __aout_fdnlist },
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#endif
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#ifdef _NLIST_DO_ELF
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{ __elf_fdnlist },
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#endif
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};
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int
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__fdnlist(fd, list)
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register int fd;
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register struct nlist *list;
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{
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int n = -1, i;
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for (i = 0; i < sizeof(nlist_fn) / sizeof(nlist_fn[0]); i++) {
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n = (nlist_fn[i].fn)(fd, list);
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if (n != -1)
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break;
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}
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return (n);
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}
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#define ISLAST(p) (p->n_un.n_name == 0 || p->n_un.n_name[0] == 0)
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#ifdef _NLIST_DO_AOUT
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int
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__aout_fdnlist(fd, list)
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register int fd;
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register struct nlist *list;
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{
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register struct nlist *p, *symtab;
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register caddr_t strtab, a_out_mmap;
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register off_t stroff, symoff;
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register u_long symsize;
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register int nent;
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struct exec * exec;
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struct stat st;
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/* check that file is at least as large as struct exec! */
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if ((_fstat(fd, &st) < 0) || (st.st_size < sizeof(struct exec)))
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return (-1);
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/* Check for files too large to mmap. */
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if (st.st_size > SIZE_T_MAX) {
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errno = EFBIG;
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return (-1);
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}
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/*
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* Map the whole a.out file into our address space.
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* We then find the string table withing this area.
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* We do not just mmap the string table, as it probably
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* does not start at a page boundary - we save ourselves a
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* lot of nastiness by mmapping the whole file.
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*
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* This gives us an easy way to randomly access all the strings,
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* without making the memory allocation permanent as with
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* malloc/free (i.e., munmap will return it to the system).
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*/
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a_out_mmap = mmap(NULL, (size_t)st.st_size, PROT_READ, MAP_PRIVATE, fd, (off_t)0);
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if (a_out_mmap == MAP_FAILED)
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return (-1);
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exec = (struct exec *)a_out_mmap;
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if (N_BADMAG(*exec)) {
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munmap(a_out_mmap, (size_t)st.st_size);
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return (-1);
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}
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symoff = N_SYMOFF(*exec);
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symsize = exec->a_syms;
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stroff = symoff + symsize;
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/* find the string table in our mmapped area */
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strtab = a_out_mmap + stroff;
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symtab = (struct nlist *)(a_out_mmap + symoff);
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/*
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* clean out any left-over information for all valid entries.
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* Type and value defined to be 0 if not found; historical
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* versions cleared other and desc as well. Also figure out
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* the largest string length so don't read any more of the
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* string table than we have to.
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*
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* XXX clearing anything other than n_type and n_value violates
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* the semantics given in the man page.
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*/
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nent = 0;
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for (p = list; !ISLAST(p); ++p) {
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p->n_type = 0;
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p->n_other = 0;
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p->n_desc = 0;
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p->n_value = 0;
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++nent;
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}
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while (symsize > 0) {
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register int soff;
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symsize-= sizeof(struct nlist);
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soff = symtab->n_un.n_strx;
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if (soff != 0 && (symtab->n_type & N_STAB) == 0)
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for (p = list; !ISLAST(p); p++)
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if (!strcmp(&strtab[soff], p->n_un.n_name)) {
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p->n_value = symtab->n_value;
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p->n_type = symtab->n_type;
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p->n_desc = symtab->n_desc;
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p->n_other = symtab->n_other;
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if (--nent <= 0)
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break;
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}
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symtab++;
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}
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munmap(a_out_mmap, (size_t)st.st_size);
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return (nent);
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}
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#endif
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#ifdef _NLIST_DO_ELF
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static void elf_sym_to_nlist __P((struct nlist *, Elf_Sym *, Elf_Shdr *, int));
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/*
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* __elf_is_okay__ - Determine if ehdr really
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* is ELF and valid for the target platform.
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*
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* WARNING: This is NOT a ELF ABI function and
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* as such it's use should be restricted.
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*/
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int
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__elf_is_okay__(ehdr)
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register Elf_Ehdr *ehdr;
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{
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register int retval = 0;
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/*
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* We need to check magic, class size, endianess,
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* and version before we look at the rest of the
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* Elf_Ehdr structure. These few elements are
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* represented in a machine independant fashion.
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*/
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if (IS_ELF(*ehdr) &&
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ehdr->e_ident[EI_CLASS] == ELF_TARG_CLASS &&
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ehdr->e_ident[EI_DATA] == ELF_TARG_DATA &&
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ehdr->e_ident[EI_VERSION] == ELF_TARG_VER) {
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/* Now check the machine dependant header */
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if (ehdr->e_machine == ELF_TARG_MACH &&
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ehdr->e_version == ELF_TARG_VER)
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retval = 1;
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}
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return retval;
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}
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int
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__elf_fdnlist(fd, list)
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register int fd;
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register struct nlist *list;
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{
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register struct nlist *p;
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register Elf_Off symoff = 0, symstroff = 0;
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register Elf_Word symsize = 0, symstrsize = 0;
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register Elf_Sword cc, i;
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int nent = -1;
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int errsave;
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Elf_Sym sbuf[1024];
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Elf_Sym *s;
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Elf_Ehdr ehdr;
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char *strtab = NULL;
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Elf_Shdr *shdr = NULL;
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Elf_Shdr *sh;
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Elf_Word shdr_size;
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void *base;
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struct stat st;
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/* Make sure obj is OK */
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if (lseek(fd, (off_t)0, SEEK_SET) == -1 ||
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_read(fd, &ehdr, sizeof(Elf_Ehdr)) != sizeof(Elf_Ehdr) ||
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!__elf_is_okay__(&ehdr) ||
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_fstat(fd, &st) < 0)
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return (-1);
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/* calculate section header table size */
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shdr_size = ehdr.e_shentsize * ehdr.e_shnum;
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/* Make sure it's not too big to mmap */
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if (shdr_size > SIZE_T_MAX) {
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errno = EFBIG;
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return (-1);
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}
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/* mmap section header table */
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base = mmap(NULL, (size_t)shdr_size, PROT_READ, 0, fd,
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(off_t)ehdr.e_shoff);
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if (base == MAP_FAILED)
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return (-1);
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shdr = (Elf_Shdr *)base;
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/*
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* Find the symbol table entry and it's corresponding
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* string table entry. Version 1.1 of the ABI states
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* that there is only one symbol table but that this
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* could change in the future.
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*/
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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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symoff = shdr[i].sh_offset;
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symsize = shdr[i].sh_size;
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symstroff = shdr[shdr[i].sh_link].sh_offset;
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symstrsize = shdr[shdr[i].sh_link].sh_size;
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break;
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}
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}
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/* Check for files too large to mmap. */
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if (symstrsize > SIZE_T_MAX) {
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errno = EFBIG;
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goto done;
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}
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/*
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* Map string table into our address space. This gives us
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* an easy way to randomly access all the strings, without
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* making the memory allocation permanent as with malloc/free
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* (i.e., munmap will return it to the system).
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*/
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base = mmap(NULL, (size_t)symstrsize, PROT_READ, 0, fd,
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(off_t)symstroff);
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if (base == MAP_FAILED)
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goto done;
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strtab = (char *)base;
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/*
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* clean out any left-over information for all valid entries.
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* Type and value defined to be 0 if not found; historical
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* versions cleared other and desc as well. Also figure out
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* the largest string length so don't read any more of the
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* string table than we have to.
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*
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* XXX clearing anything other than n_type and n_value violates
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* the semantics given in the man page.
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*/
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nent = 0;
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for (p = list; !ISLAST(p); ++p) {
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p->n_type = 0;
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p->n_other = 0;
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p->n_desc = 0;
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p->n_value = 0;
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++nent;
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}
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/* Don't process any further if object is stripped. */
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if (symoff == 0)
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goto done;
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if (lseek(fd, (off_t) symoff, SEEK_SET) == -1) {
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nent = -1;
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goto done;
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}
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while (symsize > 0 && nent > 0) {
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cc = MIN(symsize, sizeof(sbuf));
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if (_read(fd, sbuf, cc) != cc)
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break;
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symsize -= cc;
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for (s = sbuf; cc > 0 && nent > 0; ++s, cc -= sizeof(*s)) {
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char *name;
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struct nlist *p;
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name = strtab + s->st_name;
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if (name[0] == '\0')
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continue;
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for (p = list; !ISLAST(p); p++) {
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if ((p->n_un.n_name[0] == '_' &&
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strcmp(name, p->n_un.n_name+1) == 0)
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|| strcmp(name, p->n_un.n_name) == 0) {
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elf_sym_to_nlist(p, s, shdr,
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ehdr.e_shnum);
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if (--nent <= 0)
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break;
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}
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}
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}
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}
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done:
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errsave = errno;
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if (strtab != NULL)
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munmap(strtab, symstrsize);
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if (shdr != NULL)
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munmap(shdr, shdr_size);
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errno = errsave;
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return (nent);
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}
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/*
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* Convert an Elf_Sym into an nlist structure. This fills in only the
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* n_value and n_type members.
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*/
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static void
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elf_sym_to_nlist(nl, s, shdr, shnum)
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struct nlist *nl;
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Elf_Sym *s;
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Elf_Shdr *shdr;
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int shnum;
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{
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nl->n_value = s->st_value;
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switch (s->st_shndx) {
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case SHN_UNDEF:
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case SHN_COMMON:
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nl->n_type = N_UNDF;
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break;
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case SHN_ABS:
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nl->n_type = ELF_ST_TYPE(s->st_info) == STT_FILE ?
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N_FN : N_ABS;
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break;
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default:
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if (s->st_shndx >= shnum)
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nl->n_type = N_UNDF;
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else {
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Elf_Shdr *sh = shdr + s->st_shndx;
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nl->n_type = sh->sh_type == SHT_PROGBITS ?
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(sh->sh_flags & SHF_WRITE ? N_DATA : N_TEXT) :
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(sh->sh_type == SHT_NOBITS ? N_BSS : N_UNDF);
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}
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break;
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}
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if (ELF_ST_BIND(s->st_info) == STB_GLOBAL ||
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ELF_ST_BIND(s->st_info) == STB_WEAK)
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nl->n_type |= N_EXT;
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}
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#endif /* _NLIST_DO_ELF */
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