NetBSD/lib/libc/gen/nlist_elf32.c

239 lines
6.2 KiB
C

/* $NetBSD: nlist_elf32.c,v 1.12 1998/11/13 10:26:19 christos Exp $ */
/*
* Copyright (c) 1996 Christopher G. Demetriou. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Christopher G. Demetriou
* for the NetBSD Project.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/* If not included by nlist_elf64.c, ELFSIZE won't be defined. */
#ifndef ELFSIZE
#define ELFSIZE 32
#endif
#include "namespace.h"
#include <sys/param.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <a.out.h> /* for 'struct nlist' declaration */
#include "nlist_private.h"
#if defined(NLIST_ELF32) || defined(NLIST_ELF64)
#include <sys/exec_elf.h>
#endif
#if (defined(NLIST_ELF32) && (ELFSIZE == 32)) || \
(defined(NLIST_ELF64) && (ELFSIZE == 64))
#define CONCAT(x,y) __CONCAT(x,y)
#define ELFNAME(x) CONCAT(elf,CONCAT(ELFSIZE,CONCAT(_,x)))
#define ELFNAME2(x,y) CONCAT(x,CONCAT(_elf,CONCAT(ELFSIZE,CONCAT(_,y))))
#define ELFNAMEEND(x) CONCAT(x,CONCAT(_elf,ELFSIZE))
#define ELFDEFNNAME(x) CONCAT(ELF,CONCAT(ELFSIZE,CONCAT(_,x)))
/* No need to check for off < 0 because it is unsigned */
#define check(off, size) (off + size > mappedsize)
#define BAD goto out
#define BADUNMAP goto unmap
int
ELFNAMEEND(__fdnlist)(fd, list)
int fd;
struct nlist *list;
{
struct stat st;
struct nlist *p;
char *mappedfile, *strtab;
size_t mappedsize;
Elf_Ehdr *ehdrp;
Elf_Shdr *shdrp, *symshdrp, *symstrshdrp;
Elf_Sym *symp;
Elf_Off shdr_off;
Elf_Word shdr_size;
#if (ELFSIZE == 32)
Elf32_Half nshdr;
#elif (ELFSIZE == 64)
Elf64_Half nshdr;
#endif
size_t i, nsyms;
int rv, nent;
rv = -1;
symshdrp = symstrshdrp = NULL;
/*
* If we can't fstat() the file, something bad is going on.
*/
if (fstat(fd, &st) < 0)
BAD;
/*
* Map the file in its entirety.
*/
if (st.st_size > SIZE_T_MAX) {
errno = EFBIG;
BAD;
}
mappedsize = (size_t)st.st_size;
mappedfile = mmap(NULL, mappedsize, PROT_READ, MAP_COPY|MAP_FILE,
fd, (off_t)0);
if (mappedfile == (char *)-1)
BAD;
/*
* Make sure we can access the executable's header
* directly, and make sure the recognize the executable
* as an ELF binary.
*/
if (check(0, sizeof *ehdrp))
BADUNMAP;
ehdrp = (Elf_Ehdr *)(void *)&mappedfile[0];
if (memcmp(ehdrp->e_ident, Elf_e_ident, Elf_e_siz))
BADUNMAP;
switch (ehdrp->e_machine) {
ELFDEFNNAME(MACHDEP_ID_CASES)
default:
BADUNMAP;
}
/*
* Find the symbol list and string table.
*/
nshdr = ehdrp->e_shnum;
shdr_off = ehdrp->e_shoff;
shdr_size = ehdrp->e_shentsize * nshdr;
if (check(shdr_off, shdr_size) ||
(sizeof *shdrp != ehdrp->e_shentsize))
BADUNMAP;
shdrp = (Elf_Shdr *)(void *)&mappedfile[shdr_off];
for (i = 0; i < nshdr; i++) {
if (shdrp[i].sh_type == Elf_sht_symtab) {
symshdrp = &shdrp[i];
symstrshdrp = &shdrp[shdrp[i].sh_link];
}
}
/* Make sure we're not stripped. */
if (symshdrp == NULL || symshdrp->sh_offset == 0)
BADUNMAP;
/* Make sure the symbols and strings are safely mapped. */
if (check(symshdrp->sh_offset, symshdrp->sh_size))
BADUNMAP;
if (check(symstrshdrp->sh_offset, symstrshdrp->sh_size))
BADUNMAP;
symp = (Elf_Sym *)(void *)&mappedfile[symshdrp->sh_offset];
nsyms = symshdrp->sh_size / sizeof(*symp);
strtab = &mappedfile[symstrshdrp->sh_offset];
/*
* Clean out any left-over information for all valid entries.
* Type and value are defined to be 0 if not found; historical
* versions cleared other and desc as well.
*
* XXX Clearing anything other than n_type and n_value violates
* the semantics given in the man page.
*/
nent = 0;
for (p = list; !ISLAST(p); ++p) {
p->n_type = 0;
p->n_other = 0;
p->n_desc = 0;
p->n_value = 0;
++nent;
}
for (i = 0; i < nsyms; i++) {
for (p = list; !ISLAST(p); ++p) {
const char *nlistname;
char *symtabname;
/* This may be incorrect */
nlistname = p->n_un.n_name;
if (*nlistname == '_')
nlistname++;
symtabname = &strtab[symp[i].st_name];
if (!strcmp(symtabname, nlistname)) {
/*
* Translate (roughly) from ELF to nlist
*/
p->n_value = symp[i].st_value;
switch(ELF_SYM_TYPE(symp[i].st_info)) {
case Elf_estt_notype:
p->n_type = N_UNDF;
break;
case Elf_estt_object:
p->n_type = N_DATA;
break;
case Elf_estt_func:
p->n_type = N_TEXT;
break;
case Elf_estt_file:
p->n_type = N_FN;
break;
default:
/* catch other enumerations for gcc */
break;
}
if (ELF_SYM_BIND(symp[i].st_info) !=
Elf_estb_local)
p->n_type |= N_EXT;
p->n_desc = 0; /* XXX */
p->n_other = 0; /* XXX */
if (--nent <= 0)
goto done;
break; /* into next run of outer loop */
}
}
}
done:
rv = nent;
unmap:
munmap(mappedfile, mappedsize);
out:
return (rv);
}
#endif