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 */
62static uintptr_t
63check_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
91int
92elf_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