setdynflag.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22/*
23 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27#pragma ident	"%Z%%M%	%I%	%E% SMI"
28
29/*
30 * Set bits in the DT_FLAGS_1 member of the .dynamic section of an object.
31 */
32
33#include <stdio.h>
34#include <stdlib.h>
35#include <stdarg.h>
36#include <errno.h>
37#include <libelf.h>
38#include <gelf.h>
39#include <string.h>
40#include <fcntl.h>
41#include <libgen.h>
42#include <unistd.h>
43#include <sys/types.h>
44#include <sys/stat.h>
45#include <sys/link.h>
46
47#include <util.h>
48
49/*
50 * These are here because we can't be sure (yet) that the build machine has a
51 * sys/link.h that includes the following #defines.  This tool will be executed
52 * on the build machine, so we have to use its headers (rather than the ones
53 * in $ROOT which will, by definition, be up to date).  These #defines can be
54 * removed when we're sure that all build machines have recent copies of
55 * sys/link.h.
56 */
57#ifndef	DF_1_IGNMULDEF
58#define	DF_1_IGNMULDEF	0x00040000
59#endif
60#ifndef	DF_1_NOKSYMS
61#define	DF_1_NOKSYMS	0x00080000
62#endif
63
64struct dtflagval {
65	char *fv_name;
66	ulong_t fv_val;
67};
68
69static struct dtflagval dtflagvals[] = {
70	{ "DF_1_IGNMULDEF", DF_1_IGNMULDEF },
71	{ "DF_1_NOKSYMS", DF_1_NOKSYMS },
72	{ NULL }
73};
74
75const char *progname;
76
77static void
78usage(void)
79{
80	(void) fprintf(stderr, "Usage: %s -f flag_val file\n", progname);
81	exit(2);
82}
83
84static void
85set_flag(char *ifile, ulong_t flval)
86{
87	Elf *elf;
88	Elf_Scn *scn;
89	Elf_Data *data;
90	GElf_Shdr shdr;
91	GElf_Dyn dyn;
92	int fd, secidx, nent, i;
93
94	(void) elf_version(EV_CURRENT);
95
96	if ((fd = open(ifile, O_RDWR)) < 0)
97		die("Can't open %s", ifile);
98
99	if ((elf = elf_begin(fd, ELF_C_RDWR, NULL)) == NULL)
100		elfdie("Can't start ELF for %s", ifile);
101
102	if ((secidx = findelfsecidx(elf, ".dynamic")) == -1)
103		die("Can't find .dynamic section in %s\n", ifile);
104
105	if ((scn = elf_getscn(elf, secidx)) == NULL)
106		elfdie("elf_getscn (%d)", secidx);
107
108	if (gelf_getshdr(scn, &shdr) == NULL)
109		elfdie("gelf_shdr");
110
111	if ((data = elf_getdata(scn, NULL)) == NULL)
112		elfdie("elf_getdata");
113
114	nent = shdr.sh_size / shdr.sh_entsize;
115	for (i = 0; i < nent; i++) {
116		if (gelf_getdyn(data, i, &dyn) == NULL)
117			elfdie("gelf_getdyn");
118
119		if (dyn.d_tag == DT_FLAGS_1) {
120			dyn.d_un.d_val |= (Elf64_Xword)flval;
121
122			if (gelf_update_dyn(data, i, &dyn) == 0)
123				elfdie("gelf_update_dyn");
124
125			break;
126		}
127	}
128
129	if (i == nent) {
130		die("%s's .dynamic section doesn't have a DT_FLAGS_1 "
131		    "field\n", ifile);
132	}
133
134	if (elf_update(elf, ELF_C_WRITE) == -1)
135		elfdie("Couldn't update %s with changes", ifile);
136
137	(void) elf_end(elf);
138	(void) close(fd);
139}
140
141static ulong_t
142parse_flag(char *optarg)
143{
144	ulong_t flval = 0L;
145	char *arg;
146	int i;
147
148	for (arg = strtok(optarg, ","); arg != NULL; arg = strtok(NULL, ",")) {
149		for (i = 0; dtflagvals[i].fv_name != NULL; i++) {
150			if (strcmp(dtflagvals[i].fv_name, arg) == 0)
151				flval |= dtflagvals[i].fv_val;
152		}
153	}
154
155	return (flval);
156}
157
158int
159main(int argc, char **argv)
160{
161	ulong_t flval = 0L;
162	int c;
163
164	progname = basename(argv[0]);
165
166	while ((c = getopt(argc, argv, "f:")) != EOF) {
167		switch (c) {
168		case 'f':
169			if ((flval = strtoul(optarg, NULL, 0)) == 0 &&
170			    (flval = parse_flag(optarg)) == 0)
171				usage();
172			break;
173		default:
174			usage();
175		}
176	}
177
178	if (flval == 0 || argc - optind != 1)
179		usage();
180
181	set_flag(argv[optind], flval);
182
183	return (0);
184}
185