xref: /titanic_41/usr/src/cmd/sgs/rtld/amd64/_setup.c (revision 8e22821528b08c6dba4e8176351560f316f6d0de)
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 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 /*
29  * amd64 specific setup routine  -  relocate ld.so's symbols, setup its
30  * environment, map in loadable sections of the executable.
31  *
32  * Takes base address ld.so was loaded at, address of ld.so's dynamic
33  * structure, address of process environment pointers, address of auxiliary
34  * vector and * argv[0] (process name).
35  * If errors occur, send process signal - otherwise
36  * return executable's entry point to the bootstrap routine.
37  */
38 #include	"_synonyms.h"
39 
40 #include	<signal.h>
41 #include	<stdlib.h>
42 #include	<sys/auxv.h>
43 #include	<sys/types.h>
44 #include	<sys/stat.h>
45 #include	<link.h>
46 #include	<dlfcn.h>
47 #include	<debug.h>
48 #include	"_rtld.h"
49 #include	"_audit.h"
50 #include	"msg.h"
51 
52 extern int	_end;
53 extern int	_etext;
54 
55 
56 /* VARARGS */
57 unsigned long
58 _setup(Boot * ebp, Dyn * ld_dyn)
59 {
60 	unsigned long	reladdr, relacount, ld_base = 0;
61 	unsigned long	relaent = 0, pltrelsz = 0;
62 	unsigned long	strtab, soname, interp_base = 0;
63 	char		*_rt_name, **_envp, **_argv;
64 	int		_syspagsz = 0, fd = -1, dz_fd = FD_UNAVAIL;
65 	uint_t		_flags = 0, hwcap_1 = 0;
66 	Dyn *		dyn_ptr;
67 	Phdr *		phdr = 0;
68 	Rt_map *	lmp;
69 	auxv_t		*auxv, *_auxv;
70 	uid_t		uid = (uid_t)-1, euid = (uid_t)-1;
71 	gid_t		gid = (gid_t)-1, egid = (gid_t)-1;
72 	char		*_platform = 0, *_execname = 0, *_emulator = 0;
73 	int		auxflags = -1;
74 	/*
75 	 * Scan the bootstrap structure to pick up the basics.
76 	 */
77 	for (; ebp->eb_tag != EB_NULL; ebp++)
78 		switch (ebp->eb_tag) {
79 		case EB_LDSO_BASE:
80 			ld_base = (unsigned long)ebp->eb_un.eb_val;
81 			break;
82 		case EB_ARGV:
83 			_argv = (char **)ebp->eb_un.eb_ptr;
84 			break;
85 		case EB_ENVP:
86 			_envp = (char **)ebp->eb_un.eb_ptr;
87 			break;
88 		case EB_AUXV:
89 			_auxv = (auxv_t *)ebp->eb_un.eb_ptr;
90 			break;
91 		case EB_DEVZERO:
92 			dz_fd = (int)ebp->eb_un.eb_val;
93 			break;
94 		case EB_PAGESIZE:
95 			_syspagsz = (int)ebp->eb_un.eb_val;
96 			break;
97 		}
98 
99 	/*
100 	 * Search the aux. vector for the information passed by exec.
101 	 */
102 	for (auxv = _auxv; auxv->a_type != AT_NULL; auxv++) {
103 		switch (auxv->a_type) {
104 		case AT_EXECFD:
105 			/* this is the old exec that passes a file descriptor */
106 			fd = (int)auxv->a_un.a_val;
107 			break;
108 		case AT_FLAGS:
109 			/* processor flags (MAU available, etc) */
110 			_flags = auxv->a_un.a_val;
111 			break;
112 		case AT_PAGESZ:
113 			/* system page size */
114 			_syspagsz = (int)auxv->a_un.a_val;
115 			break;
116 		case AT_PHDR:
117 			/* address of the segment table */
118 			phdr = (Phdr *)auxv->a_un.a_ptr;
119 			break;
120 		case AT_BASE:
121 			/* interpreter base address */
122 			if (ld_base == 0)
123 				ld_base = auxv->a_un.a_val;
124 			interp_base = auxv->a_un.a_val;
125 			break;
126 		case AT_SUN_UID:
127 			/* effective user id for the executable */
128 			euid = (uid_t)auxv->a_un.a_val;
129 			break;
130 		case AT_SUN_RUID:
131 			/* real user id for the executable */
132 			uid = (uid_t)auxv->a_un.a_val;
133 			break;
134 		case AT_SUN_GID:
135 			/* effective group id for the executable */
136 			egid = (gid_t)auxv->a_un.a_val;
137 			break;
138 		case AT_SUN_RGID:
139 			/* real group id for the executable */
140 			gid = (gid_t)auxv->a_un.a_val;
141 			break;
142 		case AT_SUN_PLATFORM:
143 			/* platform name */
144 			_platform = auxv->a_un.a_ptr;
145 			break;
146 		case AT_SUN_EXECNAME:
147 			/* full pathname of execed object */
148 			_execname = auxv->a_un.a_ptr;
149 			break;
150 		case AT_SUN_AUXFLAGS:
151 			auxflags = (int)auxv->a_un.a_val;
152 			break;
153 		case AT_SUN_HWCAP:
154 			hwcap_1 = (uint_t)auxv->a_un.a_val;
155 			break;
156 #ifdef	AT_SUN_EMULATOR			/* Emulation library name */
157 		case AT_SUN_EMULATOR:
158 			/* name of emulation library, if any */
159 			_emulator = auxv->a_un.a_ptr;
160 			break;
161 #endif
162 		}
163 	}
164 
165 	/*
166 	 * Get needed info from ld.so's dynamic structure.
167 	 */
168 	/* LINTED */
169 	dyn_ptr = (Dyn *)((char *)ld_dyn + ld_base);
170 	for (ld_dyn = dyn_ptr; ld_dyn->d_tag != DT_NULL; ld_dyn++) {
171 		switch (ld_dyn->d_tag) {
172 		case DT_RELA:
173 			reladdr = ld_dyn->d_un.d_ptr + ld_base;
174 			break;
175 		case DT_RELACOUNT:
176 			relacount = ld_dyn->d_un.d_val;
177 			break;
178 		case DT_RELAENT:
179 			relaent = ld_dyn->d_un.d_val;
180 			break;
181 		case DT_PLTRELSZ:
182 			pltrelsz = ld_dyn->d_un.d_val;
183 			break;
184 		case DT_STRTAB:
185 			strtab = ld_dyn->d_un.d_ptr + ld_base;
186 			break;
187 		case DT_SONAME:
188 			soname = ld_dyn->d_un.d_val;
189 			break;
190 		}
191 	}
192 	_rt_name = (char *)strtab + soname;
193 
194 	/*
195 	 * If we don't have a RELAENT, just assume
196 	 * the size.
197 	 */
198 	if (relaent == 0)
199 		relaent = sizeof (Rela);
200 	/*
201 	 * Relocate all symbols in ld.so.
202 	 *
203 	 * Because ld.so.1 is built with -Bsymbolic there should only be
204 	 * RELATIVE and JMPSLOT relocations, both of which get relative
205 	 * additions against them.
206 	 */
207 	relacount += (pltrelsz / relaent);
208 	for (; relacount; relacount--) {
209 		ulong_t	roffset;
210 
211 		roffset = ((Rela *)reladdr)->r_offset + ld_base;
212 		*((ulong_t *)roffset) += ld_base +
213 		    ((Rela *)reladdr)->r_addend;
214 		reladdr += relaent;
215 	}
216 
217 	/*
218 	 * If an emulation library is being used, use that as the linker's
219 	 * effective executable name. The real executable is not linked by this
220 	 * linker.
221 	 */
222 	if (_emulator != NULL) {
223 		_execname = _emulator;
224 		rtld_flags2 |= RT_FL2_BRANDED;
225 	}
226 
227 	/*
228 	 * Initialize the dyn_plt_ent_size field.  It currently contains the
229 	 * size of the dyn_plt_template.  It still needs to be aligned and have
230 	 * space for the 'dyn_data' area added.
231 	 */
232 	dyn_plt_ent_size = ROUND(dyn_plt_ent_size, M_WORD_ALIGN) +
233 	    sizeof (uintptr_t) + sizeof (uintptr_t) + sizeof (ulong_t) +
234 	    sizeof (ulong_t) + sizeof (Sym);
235 
236 	/*
237 	 * Continue with generic startup processing.
238 	 */
239 	if ((lmp = setup((char **)_envp, (auxv_t *)_auxv, _flags, _platform,
240 	    _syspagsz, _rt_name, dyn_ptr, ld_base, interp_base, fd, phdr,
241 	    _execname, _argv, dz_fd, uid, euid, gid, egid, NULL, auxflags,
242 	    hwcap_1)) == NULL) {
243 		rtldexit(&lml_main, 1);
244 	}
245 
246 	return (LM_ENTRY_PT(lmp)());
247 }
248