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 (c) 1998, 2010, Oracle and/or its affiliates. All rights reserved.
24 */
25
26 /*
27 * Object file dependent support for ELF objects.
28 */
29
30 #include <stdio.h>
31 #include <sys/procfs.h>
32 #include <sys/mman.h>
33 #include <dlfcn.h>
34 #include <debug.h>
35 #include <conv.h>
36 #include "_rtld.h"
37 #include "_audit.h"
38 #include "_elf.h"
39 #include "_inline_gen.h"
40 #include "msg.h"
41
42 /*
43 * For backward compatibility copy relocation processing, it can be necessary to
44 * determine if a copy destination is also the recipient of a move record. For
45 * these instances, the move record addresses are retained for is_move_data().
46 */
47 static APlist *alp = NULL;
48
49 /*
50 * Warning message for bad move target.
51 */
52 void
elf_move_bad(Lm_list * lml,Rt_map * lmp,Sym * sym,ulong_t num,Addr addr)53 elf_move_bad(Lm_list *lml, Rt_map *lmp, Sym *sym, ulong_t num, Addr addr)
54 {
55 const char *name;
56 int trace;
57
58 trace = (lml->lm_flags & LML_FLG_TRC_ENABLE) &&
59 (((rtld_flags & RT_FL_SILENCERR) == 0) ||
60 (lml->lm_flags & (LML_FLG_TRC_VERBOSE | LML_FLG_TRC_WARN)));
61
62 if ((trace == 0) && (DBG_ENABLED == 0))
63 return;
64
65 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
66 name = (const char *)(STRTAB(lmp) + sym->st_name);
67 else
68 name = MSG_INTL(MSG_STR_UNKNOWN);
69
70 if (trace)
71 (void) printf(MSG_INTL(MSG_LDD_MOVE_ERR), EC_XWORD(num), name,
72 EC_ADDR(addr));
73 else
74 DBG_CALL(Dbg_move_bad(lml, num, name, addr));
75 }
76
77 /*
78 * Move data. Apply sparse initialization to data in zeroed bss.
79 */
80 int
move_data(Rt_map * lmp,APlist ** textrel)81 move_data(Rt_map *lmp, APlist **textrel)
82 {
83 Lm_list *lml = LIST(lmp);
84 Move *mv = MOVETAB(lmp);
85 ulong_t num, mvnum = MOVESZ(lmp) / MOVEENT(lmp);
86 int moves;
87
88 /*
89 * If these records are against the executable, and the executable was
90 * built prior to Solaris 8, keep track of the move record symbol. See
91 * comment in analyze.c:lookup_sym_interpose() in regards Solaris 8
92 * objects and DT_FLAGS.
93 */
94 moves = (lmp == lml->lm_head) && ((FLAGS1(lmp) & FL1_RT_DTFLAGS) == 0);
95
96 DBG_CALL(Dbg_move_data(lmp));
97 for (num = 0; num < mvnum; num++, mv++) {
98 mmapobj_result_t *mpp;
99 Addr addr, taddr;
100 Half rep, repno, stride;
101 Sym *sym;
102
103 if ((sym = (Sym *)SYMTAB(lmp) + ELF_M_SYM(mv->m_info)) == 0)
104 continue;
105
106 stride = mv->m_stride + 1;
107 addr = sym->st_value;
108
109 /*
110 * Determine the move data target, and verify the address is
111 * writable.
112 */
113 if ((FLAGS(lmp) & FLG_RT_FIXED) == 0)
114 addr += ADDR(lmp);
115 taddr = addr + mv->m_poffset;
116
117 if ((mpp = find_segment((caddr_t)taddr, lmp)) == NULL) {
118 elf_move_bad(lml, lmp, sym, num, taddr);
119 continue;
120 }
121 if (((mpp->mr_prot & PROT_WRITE) == 0) &&
122 ((set_prot(lmp, mpp, 1) == 0) ||
123 (aplist_append(textrel, mpp, AL_CNT_TEXTREL) == NULL)))
124 return (0);
125
126 DBG_CALL(Dbg_move_entry2(lml, mv, sym->st_name,
127 (const char *)(sym->st_name + STRTAB(lmp))));
128
129 for (rep = 0, repno = 0; rep < mv->m_repeat; rep++) {
130 DBG_CALL(Dbg_move_expand(lml, mv, taddr));
131
132 switch (ELF_M_SIZE(mv->m_info)) {
133 case 1:
134 *((char *)taddr) = (char)mv->m_value;
135 taddr += stride;
136 repno++;
137 break;
138 case 2:
139 /* LINTED */
140 *((Half *)taddr) = (Half)mv->m_value;
141 taddr += 2 * stride;
142 repno++;
143 break;
144 case 4:
145 /* LINTED */
146 *((Word *)taddr) = (Word)mv->m_value;
147 taddr += 4 * stride;
148 repno++;
149 break;
150 case 8:
151 /* LINTED */
152 *((unsigned long long *)taddr) = mv->m_value;
153 taddr += 8 * stride;
154 repno++;
155 break;
156 default:
157 eprintf(lml, ERR_NONE, MSG_INTL(MSG_MOVE_ERR1));
158 break;
159 }
160 }
161
162 /*
163 * If any move records have been applied to this symbol, retain
164 * the symbol address if required for backward compatibility
165 * copy relocation processing.
166 */
167 if (moves && repno &&
168 (aplist_append(&alp, (void *)addr, AL_CNT_MOVES) == NULL))
169 return (0);
170 }
171
172 /*
173 * Binaries built in the early 1990's prior to Solaris 8, using the ild
174 * incremental linker are known to have zero filled move sections
175 * (presumably place holders for new, incoming move sections). If no
176 * move records have been processed, remove the move identifier to
177 * optimize the amount of backward compatibility copy relocation
178 * processing that is needed.
179 */
180 if (moves && (alp == NULL))
181 FLAGS(lmp) &= ~FLG_RT_MOVE;
182
183 return (1);
184 }
185
186 /*
187 * Determine whether an address is the recipient of a move record.
188 * Returns 1 if the address matches a move symbol, 0 otherwise.
189 */
190 int
is_move_data(caddr_t addr)191 is_move_data(caddr_t addr)
192 {
193 caddr_t maddr;
194 Aliste idx;
195
196 for (APLIST_TRAVERSE(alp, idx, maddr)) {
197 if (addr == maddr)
198 return (1);
199 }
200 return (0);
201 }
202