2c4575477e
I used the wrong type when setting st_name in the symbol table entry struct. It's an Elf64_Word which is defined as an unsigned 32 bit int on both 32 and 64 bit platforms. To make things sensible, define some new macros to use as "word" macros and use those, rather than simply using the explicit 32 bit macros.
397 lines
11 KiB
C
397 lines
11 KiB
C
/*
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* Copyright (c) 1997 Christopher G. Demetriou. 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 Christopher G. Demetriou
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* for the NetBSD Project.
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* 4. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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#ifndef lint
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#if 0
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__RCSID("$NetBSD: exec_elf32.c,v 1.4 1997/08/12 06:07:24 mikel Exp $");
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#endif
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#endif
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__FBSDID("$FreeBSD$");
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#ifndef ELFSIZE
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#define ELFSIZE 32
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#endif
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#include <sys/types.h>
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#include <sys/endian.h>
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#include <sys/stat.h>
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#include <errno.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "extern.h"
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#if (defined(NLIST_ELF32) && (ELFSIZE == 32)) || \
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(defined(NLIST_ELF64) && (ELFSIZE == 64))
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#define __ELF_WORD_SIZE ELFSIZE
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#if (ELFSIZE == 32)
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#include <sys/elf32.h>
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#define xewtoh(x) ((data == ELFDATA2MSB) ? be32toh(x) : le32toh(x))
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#define htoxew(x) ((data == ELFDATA2MSB) ? htobe32(x) : htole32(x))
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#define wewtoh(x) ((data == ELFDATA2MSB) ? be32toh(x) : le32toh(x))
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#define htowew(x) ((data == ELFDATA2MSB) ? htobe32(x) : htole32(x))
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#elif (ELFSIZE == 64)
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#include <sys/elf64.h>
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#define xewtoh(x) ((data == ELFDATA2MSB) ? be64toh(x) : le64toh(x))
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#define htoxew(x) ((data == ELFDATA2MSB) ? htobe64(x) : htole64(x))
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/* elf64 Elf64_Word are 32 bits */
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#define wewtoh(x) ((data == ELFDATA2MSB) ? be32toh(x) : le32toh(x))
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#define htowew(x) ((data == ELFDATA2MSB) ? htobe32(x) : htole32(x))
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#endif
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#include <sys/elf_generic.h>
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#define CONCAT(x,y) __CONCAT(x,y)
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#define ELFNAME(x) CONCAT(elf,CONCAT(ELFSIZE,CONCAT(_,x)))
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#define ELFNAME2(x,y) CONCAT(x,CONCAT(_elf,CONCAT(ELFSIZE,CONCAT(_,y))))
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#define ELFNAMEEND(x) CONCAT(x,CONCAT(_elf,ELFSIZE))
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#define ELFDEFNNAME(x) CONCAT(ELF,CONCAT(ELFSIZE,CONCAT(_,x)))
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#define xe16toh(x) ((data == ELFDATA2MSB) ? be16toh(x) : le16toh(x))
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#define xe32toh(x) ((data == ELFDATA2MSB) ? be32toh(x) : le32toh(x))
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#define htoxe32(x) ((data == ELFDATA2MSB) ? htobe32(x) : htole32(x))
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struct listelem {
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struct listelem *next;
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void *mem;
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off_t file;
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size_t size;
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};
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static ssize_t
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xreadatoff(int fd, void *buf, off_t off, size_t size, const char *fn)
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{
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ssize_t rv;
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if (lseek(fd, off, SEEK_SET) != off) {
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perror(fn);
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return -1;
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}
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if ((rv = read(fd, buf, size)) != size) {
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fprintf(stderr, "%s: read error: %s\n", fn,
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rv == -1 ? strerror(errno) : "short read");
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return -1;
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}
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return size;
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}
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static ssize_t
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xwriteatoff(int fd, void *buf, off_t off, size_t size, const char *fn)
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{
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ssize_t rv;
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if (lseek(fd, off, SEEK_SET) != off) {
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perror(fn);
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return -1;
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}
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if ((rv = write(fd, buf, size)) != size) {
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fprintf(stderr, "%s: write error: %s\n", fn,
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rv == -1 ? strerror(errno) : "short write");
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return -1;
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}
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return size;
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}
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static void *
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xmalloc(size_t size, const char *fn, const char *use)
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{
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void *rv;
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rv = malloc(size);
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if (rv == NULL)
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fprintf(stderr, "%s: out of memory (allocating for %s)\n",
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fn, use);
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return (rv);
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}
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static void *
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xrealloc(void *ptr, size_t size, const char *fn, const char *use)
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{
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void *rv;
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rv = realloc(ptr, size);
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if (rv == NULL) {
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free(ptr);
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fprintf(stderr, "%s: out of memory (reallocating for %s)\n",
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fn, use);
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}
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return (rv);
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}
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int
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ELFNAMEEND(check)(int fd, const char *fn)
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{
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Elf_Ehdr eh;
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struct stat sb;
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unsigned char data;
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/*
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* Check the header to maek sure it's an ELF file (of the
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* appropriate size).
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*/
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if (fstat(fd, &sb) == -1)
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return 0;
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if (sb.st_size < sizeof eh)
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return 0;
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if (read(fd, &eh, sizeof eh) != sizeof eh)
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return 0;
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if (IS_ELF(eh) == 0)
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return 0;
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data = eh.e_ident[EI_DATA];
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switch (xe16toh(eh.e_machine)) {
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case EM_386: break;
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case EM_ALPHA: break;
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#ifndef EM_ARM
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#define EM_ARM 40
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#endif
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case EM_ARM: break;
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#ifndef EM_MIPS
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#define EM_MIPS 8
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#endif
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#ifndef EM_MIPS_RS4_BE /* same as EM_MIPS_RS3_LE */
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#define EM_MIPS_RS4_BE 10
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#endif
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case EM_MIPS: break;
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case /* EM_MIPS_RS3_LE */ EM_MIPS_RS4_BE: break;
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#ifndef EM_IA_64
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#define EM_IA_64 50
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#endif
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case EM_IA_64: break;
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#ifndef EM_PPC
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#define EM_PPC 20
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#endif
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case EM_PPC: break;
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#ifndef EM_PPC64
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#define EM_PPC64 21
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#endif
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case EM_PPC64: break;
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#ifndef EM_SPARCV9
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#define EM_SPARCV9 43
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#endif
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case EM_SPARCV9: break;
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#ifndef EM_X86_64
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#define EM_X86_64 62
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#endif
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case EM_X86_64: break;
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/* ELFDEFNNAME(MACHDEP_ID_CASES) */
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default:
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return 0;
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}
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return 1;
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}
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/*
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* This function 'hides' (some of) ELF executable file's symbols.
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* It hides them by renaming them to "_$$hide$$ <filename> <symbolname>".
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* Symbols in the global keep list, or which are marked as being undefined,
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* are left alone.
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*
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* An old version of this code shuffled various tables around, turning
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* global symbols to be hidden into local symbols. That lost on the
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* mips, because CALL16 relocs must reference global symbols, and, if
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* those symbols were being hidden, they were no longer global.
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*
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* The new renaming behaviour doesn't take global symbols out of the
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* namespace. However, it's ... unlikely that there will ever be
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* any collisions in practice because of the new method.
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*/
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int
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ELFNAMEEND(hide)(int fd, const char *fn)
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{
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Elf_Ehdr ehdr;
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Elf_Shdr *shdrp = NULL, *symtabshdr, *strtabshdr;
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Elf_Sym *symtabp = NULL;
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char *strtabp = NULL;
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Elf_Size nsyms, nlocalsyms, ewi;
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ssize_t shdrsize;
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int rv, i, weird;
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size_t nstrtab_size, nstrtab_nextoff, fn_size;
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char *nstrtabp = NULL;
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unsigned char data;
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Elf_Off maxoff, stroff;
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const char *weirdreason = NULL;
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rv = 0;
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if (xreadatoff(fd, &ehdr, 0, sizeof ehdr, fn) != sizeof ehdr)
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goto bad;
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data = ehdr.e_ident[EI_DATA];
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shdrsize = xe16toh(ehdr.e_shnum) * xe16toh(ehdr.e_shentsize);
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if ((shdrp = xmalloc(shdrsize, fn, "section header table")) == NULL)
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goto bad;
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if (xreadatoff(fd, shdrp, xewtoh(ehdr.e_shoff), shdrsize, fn) !=
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shdrsize)
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goto bad;
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symtabshdr = strtabshdr = NULL;
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weird = 0;
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maxoff = stroff = 0;
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for (i = 0; i < xe16toh(ehdr.e_shnum); i++) {
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if (xewtoh(shdrp[i].sh_offset) > maxoff)
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maxoff = xewtoh(shdrp[i].sh_offset);
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switch (xe32toh(shdrp[i].sh_type)) {
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case SHT_SYMTAB:
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if (symtabshdr != NULL)
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weird = 1;
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symtabshdr = &shdrp[i];
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strtabshdr = &shdrp[xe32toh(shdrp[i].sh_link)];
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/* Check whether the string table is the last section */
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stroff = xewtoh(shdrp[xe32toh(shdrp[i].sh_link)].sh_offset);
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if (!weird && xe32toh(shdrp[i].sh_link) != (xe16toh(ehdr.e_shnum) - 1)) {
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weird = 1;
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weirdreason = "string table not last section";
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}
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break;
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}
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}
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if (! weirdreason)
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weirdreason = "unsupported";
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if (symtabshdr == NULL)
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goto out;
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if (strtabshdr == NULL)
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weird = 1;
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if (!weird && stroff != maxoff) {
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weird = 1;
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weirdreason = "string table section not last in file";
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}
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if (weird) {
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fprintf(stderr, "%s: weird executable (%s)\n", fn, weirdreason);
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goto bad;
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}
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/*
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* load up everything we need
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*/
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/* symbol table */
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if ((symtabp = xmalloc(xewtoh(symtabshdr->sh_size), fn, "symbol table"))
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== NULL)
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goto bad;
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if (xreadatoff(fd, symtabp, xewtoh(symtabshdr->sh_offset),
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xewtoh(symtabshdr->sh_size), fn) != xewtoh(symtabshdr->sh_size))
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goto bad;
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/* string table */
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if ((strtabp = xmalloc(xewtoh(strtabshdr->sh_size), fn, "string table"))
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== NULL)
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goto bad;
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if (xreadatoff(fd, strtabp, xewtoh(strtabshdr->sh_offset),
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xewtoh(strtabshdr->sh_size), fn) != xewtoh(strtabshdr->sh_size))
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goto bad;
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nstrtab_size = 256;
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nstrtabp = xmalloc(nstrtab_size, fn, "new string table");
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if (nstrtabp == NULL)
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goto bad;
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nstrtab_nextoff = 0;
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fn_size = strlen(fn);
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/* Prepare data structures for symbol movement. */
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nsyms = xewtoh(symtabshdr->sh_size) / xewtoh(symtabshdr->sh_entsize);
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nlocalsyms = xe32toh(symtabshdr->sh_info);
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/* move symbols, making them local */
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for (ewi = 0; ewi < nsyms; ewi++) {
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Elf_Sym *sp = &symtabp[ewi];
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const char *symname = strtabp + xe32toh(sp->st_name);
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size_t newent_len;
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/*
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* make sure there's size for the next entry, even if it's
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* as large as it can be.
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*
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* "_$$hide$$ <filename> <symname><NUL>" ->
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* 9 + 3 + sizes of fn and sym name
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*/
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while ((nstrtab_size - nstrtab_nextoff) <
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strlen(symname) + fn_size + 12) {
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nstrtab_size *= 2;
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nstrtabp = xrealloc(nstrtabp, nstrtab_size, fn,
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"new string table");
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if (nstrtabp == NULL)
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goto bad;
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}
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sp->st_name = htowew(nstrtab_nextoff);
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/* if it's a keeper or is undefined, don't rename it. */
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if (in_keep_list(symname) ||
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(xe16toh(sp->st_shndx) == SHN_UNDEF)) {
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newent_len = sprintf(nstrtabp + nstrtab_nextoff,
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"%s", symname) + 1;
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} else {
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newent_len = sprintf(nstrtabp + nstrtab_nextoff,
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"_$$hide$$ %s %s", fn, symname) + 1;
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}
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nstrtab_nextoff += newent_len;
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}
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strtabshdr->sh_size = htoxew(nstrtab_nextoff);
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/*
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* write new tables to the file
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*/
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if (xwriteatoff(fd, shdrp, xewtoh(ehdr.e_shoff), shdrsize, fn) !=
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shdrsize)
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goto bad;
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if (xwriteatoff(fd, symtabp, xewtoh(symtabshdr->sh_offset),
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xewtoh(symtabshdr->sh_size), fn) != xewtoh(symtabshdr->sh_size))
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goto bad;
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/* write new symbol table strings */
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if ((size_t)xwriteatoff(fd, nstrtabp, xewtoh(strtabshdr->sh_offset),
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xewtoh(strtabshdr->sh_size), fn) != xewtoh(strtabshdr->sh_size))
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goto bad;
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out:
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if (shdrp != NULL)
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free(shdrp);
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if (symtabp != NULL)
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free(symtabp);
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if (strtabp != NULL)
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free(strtabp);
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return (rv);
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bad:
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rv = 1;
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goto out;
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}
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#endif /* include this size of ELF */
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