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 #include <stdio.h>
27 #include <strings.h>
28 #include <sys/elf.h>
29 #include <sys/elf_SPARC.h>
30 #include <alloca.h>
31 #include "_rtld.h"
32 #include "_elf.h"
33 #include "msg.h"
34 #include "conv.h"
35
36 /*
37 *
38 * Matrix of legal combinations of usage of a given register:
39 *
40 * Obj1\Obj2 Scratch Named
41 * Scratch OK NO
42 * Named NO *
43 *
44 * * OK if the symbols are identical, NO if they are not. Two symbols
45 * are identical if and only if one of the following is true:
46 * A. They are both global and have the same name.
47 * B. They are both local, have the same name, and are defined in
48 * the same object. (Note that a local symbol in one object is
49 * never identical to a local symbol in another object, even if the
50 * name is the same.)
51 *
52 * Matrix of legal combinations of st_shndx for the same register symbol:
53 *
54 * Obj1\Obj2 UNDEF ABS
55 * UNDEF OK OK
56 * ABS OK NO
57 */
58
59 /*
60 * Test the compatiblity of two register symbols, 0 pass, >0 fail
61 */
62 static uintptr_t
check_regsyms(Sym * sym1,const char * name1,Sym * sym2,const char * name2)63 check_regsyms(Sym *sym1, const char *name1, Sym *sym2, const char *name2)
64 {
65 if ((sym1->st_name == 0) && (sym2->st_name == 0))
66 return (0); /* scratches are always compatible */
67
68 if ((ELF_ST_BIND(sym1->st_info) == STB_LOCAL) ||
69 (ELF_ST_BIND(sym2->st_info) == STB_LOCAL)) {
70 if (sym1->st_value == sym2->st_value)
71 return (1); /* local symbol incompat */
72 return (0); /* no other prob from locals */
73 }
74
75 if (sym1->st_value == sym2->st_value) {
76 /* NOTE this just avoids strcmp */
77 if ((sym1->st_name == 0) || (sym2->st_name == 0))
78 return (2); /* can't match scratch to named */
79
80 if (strcmp(name1, name2) != 0)
81 return (4); /* diff name, same register value */
82
83 if ((sym1->st_shndx == SHN_ABS) && (sym2->st_shndx == SHN_ABS))
84 return (3); /* multiply defined */
85 } else if (strcmp(name1, name2) == 0)
86 return (5); /* same name, diff register value */
87
88 return (0);
89 }
90
91 int
elf_regsyms(Rt_map * lmp)92 elf_regsyms(Rt_map *lmp)
93 {
94 Dyn *dyn;
95 Dyninfo *dip;
96 Sym *symdef;
97 ulong_t rsymndx;
98
99 /*
100 * Scan through the .dynamic section of this object looking for all
101 * DT_REGISTER entries. For each DT_REGISTER entry found identify the
102 * register symbol it identifies and confirm that it doesn't conflict
103 * with any other register symbols.
104 */
105 for (dyn = DYN(lmp), dip = DYNINFO(lmp);
106 !(dip->di_flags & FLG_DI_IGNORE); dyn++, dip++) {
107 Reglist *rp;
108
109 if ((dip->di_flags & FLG_DI_REGISTER) == 0)
110 continue;
111
112 /*
113 * Get the local symbol table entry.
114 */
115 rsymndx = dyn->d_un.d_val;
116 symdef = (Sym *)((unsigned long)SYMTAB(lmp) +
117 (rsymndx * SYMENT(lmp)));
118
119 for (rp = reglist; rp; rp = rp->rl_next) {
120 Conv_inv_buf_t inv_buf;
121 const char *str, *sym1, *sym2;
122
123 if (rp->rl_sym == symdef) {
124 /*
125 * Same symbol definition - everything is a-ok.
126 */
127 return (1);
128 }
129
130 sym1 = (STRTAB(rp->rl_lmp) + rp->rl_sym->st_name);
131 sym2 = (STRTAB(lmp) + symdef->st_name);
132
133 if (check_regsyms(rp->rl_sym, sym1, symdef, sym2) == 0)
134 continue;
135
136 if ((str = demangle(sym1)) != sym1) {
137 char *_str = alloca(strlen(str) + 1);
138 (void) strcpy(_str, str);
139 sym1 = (const char *)_str;
140 }
141 sym2 = demangle(sym2);
142
143 if (LIST(lmp)->lm_flags & LML_FLG_TRC_WARN) {
144 (void) printf(MSG_INTL(MSG_LDD_REG_SYMCONF),
145 conv_sym_SPARC_value(symdef->st_value,
146 0, &inv_buf), NAME(rp->rl_lmp),
147 sym1, NAME(lmp), sym2);
148 } else {
149 eprintf(LIST(lmp), ERR_FATAL,
150 MSG_INTL(MSG_REG_SYMCONF),
151 conv_sym_SPARC_value(symdef->st_value,
152 0, &inv_buf), NAME(rp->rl_lmp),
153 sym1, NAME(lmp), sym2);
154 return (0);
155 }
156 }
157 if ((rp = calloc(sizeof (Reglist), 1)) == NULL)
158 return (0);
159 rp->rl_lmp = lmp;
160 rp->rl_sym = symdef;
161 rp->rl_next = reglist;
162 reglist = rp;
163 }
164 return (1);
165 }
166