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 * Copyright (c) 2012, Joyent, Inc.  All rights reserved.
33 */
34
35/*
36 * i386 specific setup routine  -  relocate ld.so's symbols, setup its
37 * environment, map in loadable sections of the executable.
38 *
39 * Takes base address ld.so was loaded at, address of ld.so's dynamic
40 * structure, address of process environment pointers, address of auxiliary
41 * vector and * argv[0] (process name).
42 * If errors occur, send process signal - otherwise
43 * return executable's entry point to the bootstrap routine.
44 */
45
46#include	<signal.h>
47#include	<stdlib.h>
48#include	<sys/auxv.h>
49#include	<sys/types.h>
50#include	<sys/stat.h>
51#include	<link.h>
52#include	<dlfcn.h>
53#include	"_rtld.h"
54#include	"_audit.h"
55#include	"msg.h"
56
57/* VARARGS */
58unsigned long
59_setup(Boot *ebp, Dyn *ld_dyn)
60{
61	ulong_t		reladdr, relcount, ld_base = 0;
62	ulong_t		relent = 0;
63	ulong_t		strtab, soname, interp_base = 0;
64	char		*_rt_name, **_envp, **_argv;
65	int		_syspagsz = 0, fd = -1;
66	uint_t		_flags = 0;
67	uint_t		hwcap[2] = { 0, 0 };
68	Dyn		*dyn_ptr;
69	Phdr		*phdr = NULL;
70	Rt_map		*lmp;
71	auxv_t		*auxv, *_auxv;
72	uid_t		uid = (uid_t)-1, euid = (uid_t)-1;
73	gid_t		gid = (gid_t)-1, egid = (gid_t)-1;
74	char		*_platform = NULL, *_execname = NULL, *_emulator = NULL;
75	int		auxflags = -1;
76
77	/*
78	 * Scan the bootstrap structure to pick up the basics.
79	 */
80	for (; ebp->eb_tag != EB_NULL; ebp++)
81		switch (ebp->eb_tag) {
82		case EB_LDSO_BASE:
83			ld_base = (unsigned long)ebp->eb_un.eb_val;
84			break;
85		case EB_ARGV:
86			_argv = (char **)ebp->eb_un.eb_ptr;
87			break;
88		case EB_ENVP:
89			_envp = (char **)ebp->eb_un.eb_ptr;
90			break;
91		case EB_AUXV:
92			_auxv = (auxv_t *)ebp->eb_un.eb_ptr;
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			/* auxiliary flags */
152			auxflags = (int)auxv->a_un.a_val;
153			break;
154		case AT_SUN_HWCAP:
155			/* hardware capabilities */
156			hwcap[0] = (uint_t)auxv->a_un.a_val;
157			break;
158		case AT_SUN_HWCAP2:
159			/* hardware capabilities */
160			hwcap[1] = (uint_t)auxv->a_un.a_val;
161			break;
162		case AT_SUN_EMULATOR:
163			/* name of emulation library, if any */
164			_emulator = auxv->a_un.a_ptr;
165			break;
166		}
167	}
168
169	/*
170	 * Get needed info from ld.so's dynamic structure.
171	 */
172	/* LINTED */
173	dyn_ptr = (Dyn *)((char *)ld_dyn + ld_base);
174	for (ld_dyn = dyn_ptr; ld_dyn->d_tag != DT_NULL; ld_dyn++) {
175		switch (ld_dyn->d_tag) {
176		case DT_REL:
177			reladdr = ld_dyn->d_un.d_ptr + ld_base;
178			break;
179		case DT_RELCOUNT:
180			relcount = ld_dyn->d_un.d_val;
181			break;
182		case DT_RELENT:
183			relent = ld_dyn->d_un.d_val;
184			break;
185		case DT_STRTAB:
186			strtab = ld_dyn->d_un.d_ptr + ld_base;
187			break;
188		case DT_SONAME:
189			soname = ld_dyn->d_un.d_val;
190			break;
191		}
192	}
193	_rt_name = (char *)strtab + soname;
194
195	/*
196	 * If we don't have a RELENT, just assume the size.
197	 */
198	if (relent == 0)
199		relent = sizeof (Rel);
200
201	/*
202	 * As all global symbol references within ld.so.1 are protected
203	 * (symbolic), only RELATIVE and JMPSLOT relocations should be left
204	 * to process at runtime.  Process all relative relocations now.
205	 */
206	for (; relcount; relcount--) {
207		ulong_t	roffset;
208
209		roffset = ((Rel *)reladdr)->r_offset + ld_base;
210		*((ulong_t *)roffset) += ld_base;
211		reladdr += relent;
212	}
213
214	/*
215	 * If an emulation library is being used, use that as the linker's
216	 * effective executable name. The real executable is not linked by this
217	 * linker.
218	 */
219	if (_emulator != NULL) {
220		_execname = _emulator;
221		rtld_flags2 |= RT_FL2_BRANDED;
222	}
223
224	/*
225	 * Initialize the dyn_plt_ent_size field.  It currently contains the
226	 * size of the dyn_plt_template.  It still needs to be aligned and have
227	 * space for the 'dyn_data' area added.
228	 */
229	dyn_plt_ent_size = ROUND(dyn_plt_ent_size, M_WORD_ALIGN) +
230	    sizeof (uintptr_t) + sizeof (uintptr_t) + sizeof (ulong_t) +
231	    sizeof (ulong_t) + sizeof (Sym);
232
233	/*
234	 * Continue with generic startup processing.
235	 */
236	if ((lmp = setup((char **)_envp, (auxv_t *)_auxv, _flags, _platform,
237	    _syspagsz, _rt_name, ld_base, interp_base, fd, phdr,
238	    _execname, _argv, uid, euid, gid, egid, NULL, auxflags,
239	    hwcap)) == NULL) {
240		rtldexit(&lml_main, 1);
241	}
242
243	return (LM_ENTRY_PT(lmp)());
244}
245