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 
64 struct dtflagval {
65 	char *fv_name;
66 	ulong_t fv_val;
67 };
68 
69 static struct dtflagval dtflagvals[] = {
70 	{ "DF_1_IGNMULDEF", DF_1_IGNMULDEF },
71 	{ "DF_1_NOKSYMS", DF_1_NOKSYMS },
72 	{ NULL }
73 };
74 
75 const char *progname;
76 
77 static void
usage(void)78 usage(void)
79 {
80 	(void) fprintf(stderr, "Usage: %s -f flag_val file\n", progname);
81 	exit(2);
82 }
83 
84 static void
set_flag(char * ifile,ulong_t flval)85 set_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 
141 static ulong_t
parse_flag(char * optarg)142 parse_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 
158 int
main(int argc,char ** argv)159 main(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