xref: /illumos-gate/usr/src/cmd/mdb/tools/setdynflag/common/setdynflag.c (revision 2a8bcb4efb45d99ac41c94a75c396b362c414f7f)
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 /*
28  * Set bits in the DT_FLAGS_1 member of the .dynamic section of an object.
29  */
30 
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <stdarg.h>
34 #include <errno.h>
35 #include <libelf.h>
36 #include <gelf.h>
37 #include <string.h>
38 #include <fcntl.h>
39 #include <libgen.h>
40 #include <unistd.h>
41 #include <sys/types.h>
42 #include <sys/stat.h>
43 #include <sys/link.h>
44 
45 #include <util.h>
46 
47 /*
48  * These are here because we can't be sure (yet) that the build machine has a
49  * sys/link.h that includes the following #defines.  This tool will be executed
50  * on the build machine, so we have to use its headers (rather than the ones
51  * in $ROOT which will, by definition, be up to date).  These #defines can be
52  * removed when we're sure that all build machines have recent copies of
53  * sys/link.h.
54  */
55 #ifndef	DF_1_IGNMULDEF
56 #define	DF_1_IGNMULDEF	0x00040000
57 #endif
58 #ifndef	DF_1_NOKSYMS
59 #define	DF_1_NOKSYMS	0x00080000
60 #endif
61 
62 struct dtflagval {
63 	char *fv_name;
64 	ulong_t fv_val;
65 };
66 
67 static struct dtflagval dtflagvals[] = {
68 	{ "DF_1_IGNMULDEF", DF_1_IGNMULDEF },
69 	{ "DF_1_NOKSYMS", DF_1_NOKSYMS },
70 	{ NULL }
71 };
72 
73 const char *progname;
74 
75 static void
usage(void)76 usage(void)
77 {
78 	(void) fprintf(stderr, "Usage: %s -f flag_val file\n", progname);
79 	exit(2);
80 }
81 
82 static void
set_flag(char * ifile,ulong_t flval)83 set_flag(char *ifile, ulong_t flval)
84 {
85 	Elf *elf;
86 	Elf_Scn *scn;
87 	Elf_Data *data;
88 	GElf_Shdr shdr;
89 	GElf_Dyn dyn;
90 	int fd, secidx, nent, i;
91 
92 	(void) elf_version(EV_CURRENT);
93 
94 	if ((fd = open(ifile, O_RDWR)) < 0)
95 		die("Can't open %s", ifile);
96 
97 	if ((elf = elf_begin(fd, ELF_C_RDWR, NULL)) == NULL)
98 		elfdie("Can't start ELF for %s", ifile);
99 
100 	if ((secidx = findelfsecidx(elf, ".dynamic")) == -1)
101 		die("Can't find .dynamic section in %s\n", ifile);
102 
103 	if ((scn = elf_getscn(elf, secidx)) == NULL)
104 		elfdie("elf_getscn (%d)", secidx);
105 
106 	if (gelf_getshdr(scn, &shdr) == NULL)
107 		elfdie("gelf_shdr");
108 
109 	if ((data = elf_getdata(scn, NULL)) == NULL)
110 		elfdie("elf_getdata");
111 
112 	nent = shdr.sh_size / shdr.sh_entsize;
113 	for (i = 0; i < nent; i++) {
114 		if (gelf_getdyn(data, i, &dyn) == NULL)
115 			elfdie("gelf_getdyn");
116 
117 		if (dyn.d_tag == DT_FLAGS_1) {
118 			dyn.d_un.d_val |= (Elf64_Xword)flval;
119 
120 			if (gelf_update_dyn(data, i, &dyn) == 0)
121 				elfdie("gelf_update_dyn");
122 
123 			break;
124 		}
125 	}
126 
127 	if (i == nent) {
128 		die("%s's .dynamic section doesn't have a DT_FLAGS_1 "
129 		    "field\n", ifile);
130 	}
131 
132 	if (elf_update(elf, ELF_C_WRITE) == -1)
133 		elfdie("Couldn't update %s with changes", ifile);
134 
135 	(void) elf_end(elf);
136 	(void) close(fd);
137 }
138 
139 static ulong_t
parse_flag(char * optarg)140 parse_flag(char *optarg)
141 {
142 	ulong_t flval = 0L;
143 	char *arg;
144 	int i;
145 
146 	for (arg = strtok(optarg, ","); arg != NULL; arg = strtok(NULL, ",")) {
147 		for (i = 0; dtflagvals[i].fv_name != NULL; i++) {
148 			if (strcmp(dtflagvals[i].fv_name, arg) == 0)
149 				flval |= dtflagvals[i].fv_val;
150 		}
151 	}
152 
153 	return (flval);
154 }
155 
156 int
main(int argc,char ** argv)157 main(int argc, char **argv)
158 {
159 	ulong_t flval = 0L;
160 	int c;
161 
162 	progname = basename(argv[0]);
163 
164 	while ((c = getopt(argc, argv, "f:")) != EOF) {
165 		switch (c) {
166 		case 'f':
167 			if ((flval = strtoul(optarg, NULL, 0)) == 0 &&
168 			    (flval = parse_flag(optarg)) == 0)
169 				usage();
170 			break;
171 		default:
172 			usage();
173 		}
174 	}
175 
176 	if (flval == 0 || argc - optind != 1)
177 		usage();
178 
179 	set_flag(argv[optind], flval);
180 
181 	return (0);
182 }
183