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 (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /*
28 * Copyright (c) 1988 AT&T
29 * All Rights Reserved
30 */
31
32 /*
33 * i386 specific setup routine - relocate ld.so's symbols, setup its
34 * environment, map in loadable sections of the executable.
35 *
36 * Takes base address ld.so was loaded at, address of ld.so's dynamic
37 * structure, address of process environment pointers, address of auxiliary
38 * vector and * argv[0] (process name).
39 * If errors occur, send process signal - otherwise
40 * return executable's entry point to the bootstrap routine.
41 */
42
43 #include <signal.h>
44 #include <stdlib.h>
45 #include <sys/auxv.h>
46 #include <sys/types.h>
47 #include <sys/stat.h>
48 #include <link.h>
49 #include <dlfcn.h>
50 #include "_rtld.h"
51 #include "_audit.h"
52 #include "msg.h"
53
54 /* VARARGS */
55 unsigned long
_setup(Boot * ebp,Dyn * ld_dyn)56 _setup(Boot *ebp, Dyn *ld_dyn)
57 {
58 ulong_t reladdr, relcount, ld_base = 0;
59 ulong_t relent = 0;
60 ulong_t strtab, soname, interp_base = 0;
61 char *_rt_name, **_envp, **_argv;
62 int _syspagsz = 0, fd = -1;
63 uint_t _flags = 0, hwcap_1 = 0;
64 Dyn *dyn_ptr;
65 Phdr *phdr = NULL;
66 Rt_map *lmp;
67 auxv_t *auxv, *_auxv;
68 uid_t uid = (uid_t)-1, euid = (uid_t)-1;
69 gid_t gid = (gid_t)-1, egid = (gid_t)-1;
70 char *_platform = NULL, *_execname = NULL, *_emulator = NULL;
71 int auxflags = -1;
72
73 /*
74 * Scan the bootstrap structure to pick up the basics.
75 */
76 for (; ebp->eb_tag != EB_NULL; ebp++)
77 switch (ebp->eb_tag) {
78 case EB_LDSO_BASE:
79 ld_base = (unsigned long)ebp->eb_un.eb_val;
80 break;
81 case EB_ARGV:
82 _argv = (char **)ebp->eb_un.eb_ptr;
83 break;
84 case EB_ENVP:
85 _envp = (char **)ebp->eb_un.eb_ptr;
86 break;
87 case EB_AUXV:
88 _auxv = (auxv_t *)ebp->eb_un.eb_ptr;
89 break;
90 case EB_PAGESIZE:
91 _syspagsz = (int)ebp->eb_un.eb_val;
92 break;
93 }
94
95 /*
96 * Search the aux. vector for the information passed by exec.
97 */
98 for (auxv = _auxv; auxv->a_type != AT_NULL; auxv++) {
99 switch (auxv->a_type) {
100 case AT_EXECFD:
101 /* this is the old exec that passes a file descriptor */
102 fd = (int)auxv->a_un.a_val;
103 break;
104 case AT_FLAGS:
105 /* processor flags (MAU available, etc) */
106 _flags = auxv->a_un.a_val;
107 break;
108 case AT_PAGESZ:
109 /* system page size */
110 _syspagsz = (int)auxv->a_un.a_val;
111 break;
112 case AT_PHDR:
113 /* address of the segment table */
114 phdr = (Phdr *)auxv->a_un.a_ptr;
115 break;
116 case AT_BASE:
117 /* interpreter base address */
118 if (ld_base == 0)
119 ld_base = auxv->a_un.a_val;
120 interp_base = auxv->a_un.a_val;
121 break;
122 case AT_SUN_UID:
123 /* effective user id for the executable */
124 euid = (uid_t)auxv->a_un.a_val;
125 break;
126 case AT_SUN_RUID:
127 /* real user id for the executable */
128 uid = (uid_t)auxv->a_un.a_val;
129 break;
130 case AT_SUN_GID:
131 /* effective group id for the executable */
132 egid = (gid_t)auxv->a_un.a_val;
133 break;
134 case AT_SUN_RGID:
135 /* real group id for the executable */
136 gid = (gid_t)auxv->a_un.a_val;
137 break;
138 case AT_SUN_PLATFORM:
139 /* platform name */
140 _platform = auxv->a_un.a_ptr;
141 break;
142 case AT_SUN_EXECNAME:
143 /* full pathname of execed object */
144 _execname = auxv->a_un.a_ptr;
145 break;
146 case AT_SUN_AUXFLAGS:
147 /* auxiliary flags */
148 auxflags = (int)auxv->a_un.a_val;
149 break;
150 case AT_SUN_HWCAP:
151 /* hardware capabilities */
152 hwcap_1 = (uint_t)auxv->a_un.a_val;
153 break;
154 case AT_SUN_EMULATOR:
155 /* name of emulation library, if any */
156 _emulator = auxv->a_un.a_ptr;
157 break;
158 }
159 }
160
161 /*
162 * Get needed info from ld.so's dynamic structure.
163 */
164 /* LINTED */
165 dyn_ptr = (Dyn *)((char *)ld_dyn + ld_base);
166 for (ld_dyn = dyn_ptr; ld_dyn->d_tag != DT_NULL; ld_dyn++) {
167 switch (ld_dyn->d_tag) {
168 case DT_REL:
169 reladdr = ld_dyn->d_un.d_ptr + ld_base;
170 break;
171 case DT_RELCOUNT:
172 relcount = ld_dyn->d_un.d_val;
173 break;
174 case DT_RELENT:
175 relent = ld_dyn->d_un.d_val;
176 break;
177 case DT_STRTAB:
178 strtab = ld_dyn->d_un.d_ptr + ld_base;
179 break;
180 case DT_SONAME:
181 soname = ld_dyn->d_un.d_val;
182 break;
183 }
184 }
185 _rt_name = (char *)strtab + soname;
186
187 /*
188 * If we don't have a RELENT, just assume the size.
189 */
190 if (relent == 0)
191 relent = sizeof (Rel);
192
193 /*
194 * As all global symbol references within ld.so.1 are protected
195 * (symbolic), only RELATIVE and JMPSLOT relocations should be left
196 * to process at runtime. Process all relative relocations now.
197 */
198 for (; relcount; relcount--) {
199 ulong_t roffset;
200
201 roffset = ((Rel *)reladdr)->r_offset + ld_base;
202 *((ulong_t *)roffset) += ld_base;
203 reladdr += relent;
204 }
205
206 /*
207 * If an emulation library is being used, use that as the linker's
208 * effective executable name. The real executable is not linked by this
209 * linker.
210 */
211 if (_emulator != NULL) {
212 _execname = _emulator;
213 rtld_flags2 |= RT_FL2_BRANDED;
214 }
215
216 /*
217 * Initialize the dyn_plt_ent_size field. It currently contains the
218 * size of the dyn_plt_template. It still needs to be aligned and have
219 * space for the 'dyn_data' area added.
220 */
221 dyn_plt_ent_size = ROUND(dyn_plt_ent_size, M_WORD_ALIGN) +
222 sizeof (uintptr_t) + sizeof (uintptr_t) + sizeof (ulong_t) +
223 sizeof (ulong_t) + sizeof (Sym);
224
225 /*
226 * Continue with generic startup processing.
227 */
228 if ((lmp = setup((char **)_envp, (auxv_t *)_auxv, _flags, _platform,
229 _syspagsz, _rt_name, ld_base, interp_base, fd, phdr,
230 _execname, _argv, uid, euid, gid, egid, NULL, auxflags,
231 hwcap_1)) == NULL) {
232 rtldexit(&lml_main, 1);
233 }
234
235 return (LM_ENTRY_PT(lmp)());
236 }
237