xref: /illumos-gate/usr/src/cmd/sgs/libelf/common/error.c (revision 7257d1b4)
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 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <thread.h>
30 #include <pthread.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <stdio.h>
34 #include <libelf.h>
35 #include <libintl.h>
36 #include "msg.h"
37 #include "decl.h"
38 
39 #define	ELFERRSHIFT	16
40 #define	SYSERRMASK	0xffff
41 
42 
43 /*
44  * _elf_err has two values encoded in it, both the _elf_err # and
45  * the system errno value (if relevant).  These values are encoded
46  * in the upper & lower 16 bits of the 4 byte integer.
47  */
48 static int		_elf_err = 0;
49 
50 #if !defined(NATIVE_BUILD)
51 
52 static thread_key_t	errkey = THR_ONCE_KEY;
53 static thread_key_t	bufkey = THR_ONCE_KEY;
54 
55 #else	/* NATIVE_BUILD */
56 
57 /*
58  * This code is here to enable the building of a native version
59  * of libelf.so when the build machine has not yet been upgraded
60  * to a version of libc that provides thr_keycreate_once().
61  * It should be deleted when solaris_nevada ships.
62  * The code is not MT-safe in a relaxed memory model.
63  */
64 
65 static thread_key_t	errkey = 0;
66 static thread_key_t	bufkey = 0;
67 
68 int
69 thr_keycreate_once(thread_key_t *keyp, void (*destructor)(void *))
70 {
71 	static mutex_t key_lock = DEFAULTMUTEX;
72 	thread_key_t key;
73 	int error;
74 
75 	if (*keyp == 0) {
76 		mutex_lock(&key_lock);
77 		if (*keyp == 0) {
78 			error = thr_keycreate(&key, destructor);
79 			if (error) {
80 				mutex_unlock(&key_lock);
81 				return (error);
82 			}
83 			*keyp = key;
84 		}
85 		mutex_unlock(&key_lock);
86 	}
87 
88 	return (0);
89 }
90 
91 #endif	/* NATIVE_BUILD */
92 
93 
94 const char *
95 _libelf_msg(Msg mid)
96 {
97 	return (dgettext(MSG_ORIG(MSG_SUNW_OST_SGS), MSG_ORIG(mid)));
98 }
99 
100 
101 void
102 _elf_seterr(Msg lib_err, int sys_err)
103 {
104 	/*LINTED*/
105 	intptr_t encerr = ((int)lib_err << ELFERRSHIFT) |
106 	    (sys_err & SYSERRMASK);
107 
108 #ifndef	__lock_lint
109 	if (thr_main()) {
110 		_elf_err = (int)encerr;
111 		return;
112 	}
113 #endif
114 	(void) thr_keycreate_once(&errkey, 0);
115 	(void) thr_setspecific(errkey, (void *)encerr);
116 }
117 
118 int
119 _elf_geterr() {
120 #ifndef	__lock_lint
121 	if (thr_main())
122 		return (_elf_err);
123 #endif
124 	return ((uintptr_t)pthread_getspecific(errkey));
125 }
126 
127 const char *
128 elf_errmsg(int err)
129 {
130 	char			*errno_str;
131 	char			*elferr_str;
132 	char			*buffer = 0;
133 	int			syserr;
134 	int			elferr;
135 	static char		intbuf[MAXELFERR];
136 
137 	if (err == 0) {
138 		if ((err = _elf_geterr()) == 0)
139 			return (0);
140 	} else if (err == -1) {
141 		if ((err = _elf_geterr()) == 0)
142 			/*LINTED*/ /* MSG_INTL(EINF_NULLERROR) */
143 			err = (int)EINF_NULLERROR << ELFERRSHIFT;
144 	}
145 
146 	if (thr_main())
147 		buffer = intbuf;
148 	else {
149 		/*
150 		 * If this is a threaded APP then we store the
151 		 * errmsg buffer in Thread Specific Storage.
152 		 *
153 		 * Each thread has its own private buffer.
154 		 */
155 		if (thr_keycreate_once(&bufkey, free) != 0)
156 			return (MSG_INTL(EBUG_THRDKEY));
157 		buffer = pthread_getspecific(bufkey);
158 
159 		if (!buffer) {
160 			if ((buffer = malloc(MAXELFERR)) == 0)
161 				return (MSG_INTL(EMEM_ERRMSG));
162 			if (thr_setspecific(bufkey, buffer) != 0) {
163 				free(buffer);
164 				return (MSG_INTL(EBUG_THRDSET));
165 			}
166 		}
167 	}
168 
169 	elferr = (int)((uint_t)err >> ELFERRSHIFT);
170 	syserr = err & SYSERRMASK;
171 	/*LINTED*/
172 	elferr_str = (char *)MSG_INTL(elferr);
173 	if (syserr && (errno_str = strerror(syserr)))
174 		(void) snprintf(buffer, MAXELFERR,
175 		    MSG_ORIG(MSG_FMT_ERR), elferr_str, errno_str);
176 	else {
177 		(void) strncpy(buffer, elferr_str, MAXELFERR - 1);
178 		buffer[MAXELFERR - 1] = '\0';
179 	}
180 
181 	return (buffer);
182 }
183 
184 int
185 elf_errno()
186 {
187 	int	rc = _elf_geterr();
188 
189 	_elf_seterr(0, 0);
190 	return (rc);
191 }
192