1.1 --- a/src/os/solaris/fix_empty_sec_hdr_flags/fix_empty_sec_hdr_flags.c Fri Nov 14 07:51:50 2014 -0800
1.2 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000
1.3 @@ -1,181 +0,0 @@
1.4 -/*
1.5 - * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
1.6 - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 - *
1.8 - * This code is free software; you can redistribute it and/or modify it
1.9 - * under the terms of the GNU General Public License version 2 only, as
1.10 - * published by the Free Software Foundation.
1.11 - *
1.12 - * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 - * version 2 for more details (a copy is included in the LICENSE file that
1.16 - * accompanied this code).
1.17 - *
1.18 - * You should have received a copy of the GNU General Public License version
1.19 - * 2 along with this work; if not, write to the Free Software Foundation,
1.20 - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 - *
1.22 - * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 - * or visit www.oracle.com if you need additional information or have any
1.24 - * questions.
1.25 - *
1.26 - */
1.27 -
1.28 -/*
1.29 - * Name: fix_empty_sec_hdr_flags.c
1.30 - *
1.31 - * Description: Remove the SHF_ALLOC flag from "empty" section headers.
1.32 - * An "empty" section header has sh_addr == 0 and sh_size == 0.
1.33 - *
1.34 - * This program is adapted from the example program shown on the
1.35 - * elf(3elf) man page and from code from the Solaris compiler
1.36 - * driver.
1.37 - */
1.38 -
1.39 -#include <fcntl.h>
1.40 -#include <stdio.h>
1.41 -#include <libelf.h>
1.42 -#include <stdlib.h>
1.43 -#include <string.h>
1.44 -#include <unistd.h>
1.45 -
1.46 -static void failure(void);
1.47 -
1.48 -void
1.49 -main(int argc, char ** argv) {
1.50 - void * ehdr; /* ELF header */
1.51 - unsigned int i; /* section counter */
1.52 - int fd; /* descriptor for file */
1.53 - Elf * elf; /* ELF descriptor */
1.54 - char * elf_ident; /* ELF identity string */
1.55 - char * elf_obj; /* elf_obj file */
1.56 - int fix_count; /* number of flags fixed */
1.57 - int is_elfclass64; /* is an ELFCLASS64 file? */
1.58 - Elf_Scn * scn; /* ELF section descriptor */
1.59 - void * shdr; /* ELF section header */
1.60 - Elf_Data * shstrtab; /* ELF section header string table */
1.61 -
1.62 - if (argc != 2) {
1.63 - (void) fprintf(stderr, "Usage: %s elf_obj\n", argv[0]);
1.64 - exit(2);
1.65 - }
1.66 -
1.67 - /* open the elf_obj */
1.68 - elf_obj = argv[1];
1.69 - if ((fd = open(elf_obj, O_RDWR)) == -1) {
1.70 - (void) fprintf(stderr, "%s: cannot open file.\n", elf_obj);
1.71 - exit(3);
1.72 - }
1.73 -
1.74 - (void) printf("Opening '%s' for update\n", elf_obj);
1.75 - (void) fflush(stdout);
1.76 - (void) elf_version(EV_CURRENT); /* coordinate ELF versions */
1.77 -
1.78 - /* obtain the ELF descriptors from the input file */
1.79 - if ((elf = elf_begin(fd, ELF_C_RDWR, NULL)) == NULL) {
1.80 - failure();
1.81 - }
1.82 -
1.83 - /* determine if ELFCLASS64 or not? */
1.84 - elf_ident = elf_getident(elf, NULL);
1.85 - is_elfclass64 = (elf_ident[EI_CLASS] == ELFCLASS64);
1.86 -
1.87 - /* get the ELF header */
1.88 - if (is_elfclass64) {
1.89 - ehdr = elf64_getehdr(elf);
1.90 - } else {
1.91 - ehdr = elf32_getehdr(elf);
1.92 - }
1.93 - if (ehdr == NULL) {
1.94 - failure();
1.95 - }
1.96 -
1.97 - /* get the ELF section descriptor */
1.98 - if (is_elfclass64) {
1.99 - scn = elf_getscn(elf, ((Elf64_Ehdr *) ehdr)->e_shstrndx);
1.100 - } else {
1.101 - scn = elf_getscn(elf, ((Elf32_Ehdr *) ehdr)->e_shstrndx);
1.102 - }
1.103 - if (scn == NULL) {
1.104 - failure();
1.105 - }
1.106 -
1.107 - /* get the section header string table */
1.108 - shstrtab = elf_getdata(scn, NULL);
1.109 - if (shstrtab == NULL) {
1.110 - failure();
1.111 - }
1.112 -
1.113 - fix_count = 0;
1.114 -
1.115 - /* traverse the sections of the input file */
1.116 - for (i = 1, scn = NULL; scn = elf_nextscn(elf, scn); i++) {
1.117 - int has_flag_set; /* is SHF_ALLOC flag set? */
1.118 - int is_empty; /* is section empty? */
1.119 - char * name; /* short hand pointer */
1.120 -
1.121 - /* get the section header */
1.122 - if (is_elfclass64) {
1.123 - shdr = elf64_getshdr(scn);
1.124 - } else {
1.125 - shdr = elf32_getshdr(scn);
1.126 - }
1.127 - if (shdr == NULL) {
1.128 - failure();
1.129 - }
1.130 -
1.131 - if (is_elfclass64) {
1.132 - name = (char *)shstrtab->d_buf + ((Elf64_Shdr *) shdr)->sh_name;
1.133 - } else {
1.134 - name = (char *)shstrtab->d_buf + ((Elf32_Shdr *) shdr)->sh_name;
1.135 - }
1.136 -
1.137 - if (is_elfclass64) {
1.138 - has_flag_set = ((Elf64_Shdr *) shdr)->sh_flags & SHF_ALLOC;
1.139 - is_empty = ((Elf64_Shdr *) shdr)->sh_addr == 0 &&
1.140 - ((Elf64_Shdr *) shdr)->sh_size == 0;
1.141 - } else {
1.142 - has_flag_set = ((Elf32_Shdr *) shdr)->sh_flags & SHF_ALLOC;
1.143 - is_empty = ((Elf32_Shdr *) shdr)->sh_addr == 0 &&
1.144 - ((Elf32_Shdr *) shdr)->sh_size == 0;
1.145 - }
1.146 -
1.147 - if (is_empty && has_flag_set) {
1.148 - (void) printf("section[%u] '%s' is empty, "
1.149 - "but SHF_ALLOC flag is set.\n", i, name);
1.150 - (void) printf("Clearing the SHF_ALLOC flag.\n");
1.151 -
1.152 - if (is_elfclass64) {
1.153 - ((Elf64_Shdr *) shdr)->sh_flags &= ~SHF_ALLOC;
1.154 - } else {
1.155 - ((Elf32_Shdr *) shdr)->sh_flags &= ~SHF_ALLOC;
1.156 - }
1.157 - fix_count++;
1.158 - }
1.159 - } /* end for each ELF section */
1.160 -
1.161 - if (fix_count > 0) {
1.162 - (void) printf("Saving %d updates to '%s'\n", fix_count, elf_obj);
1.163 - (void) fflush(stdout);
1.164 - (void) elf_update(elf, ELF_C_NULL); /* recalc ELF memory structures */
1.165 - (void) elf_update(elf, ELF_C_WRITE); /* write out changes to ELF obj */
1.166 - } else {
1.167 - (void) printf("No SHF_ALLOC flags needed to be cleared.\n");
1.168 - }
1.169 -
1.170 - (void) elf_end(elf); /* done with ELF obj */
1.171 - (void) close(fd);
1.172 -
1.173 - (void) printf("Done %s '%s'\n",
1.174 - (fix_count > 0) ? "updating" : "with", elf_obj);
1.175 - (void) fflush(stdout);
1.176 - exit(0);
1.177 -} /* end main */
1.178 -
1.179 -
1.180 -static void
1.181 -failure() {
1.182 - (void) fprintf(stderr, "%s\n", elf_errmsg(elf_errno()));
1.183 - exit(6);
1.184 -}
