xref: /netbsd-src/lib/libc/gen/nlist_ecoff.c (revision 76dfffe33547c37f8bdd446e3e4ab0f3c16cea4b)
1 /*	$NetBSD: nlist_ecoff.c,v 1.3 1996/10/01 13:37:05 cgd Exp $	*/
2 
3 /*
4  * Copyright (c) 1996 Christopher G. Demetriou.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *      This product includes software developed by Christopher G. Demetriou
17  *	for the NetBSD Project.
18  * 4. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #if defined(LIBC_SCCS) && !defined(lint)
34 static char rcsid[] = "$NetBSD: nlist_ecoff.c,v 1.3 1996/10/01 13:37:05 cgd Exp $";
35 #endif /* LIBC_SCCS and not lint */
36 
37 #include <sys/param.h>
38 #include <sys/mman.h>
39 #include <sys/stat.h>
40 #include <sys/file.h>
41 
42 #include <errno.h>
43 #include <stdio.h>
44 #include <string.h>
45 #include <unistd.h>
46 #include <a.out.h>			/* for 'struct nlist' declaration */
47 
48 #include "nlist_private.h"
49 #ifdef NLIST_ECOFF
50 #include <sys/exec_ecoff.h>
51 #endif
52 
53 #ifdef NLIST_ECOFF
54 #define	check(off, size)	((off < 0) || (off + size > mappedsize))
55 #define	BAD			do { rv = -1; goto out; } while (0)
56 #define	BADUNMAP		do { rv = -1; goto unmap; } while (0)
57 
58 int
59 __fdnlist_ecoff(fd, list)
60 	register int fd;
61 	register struct nlist *list;
62 {
63 	struct nlist *p;
64 	struct ecoff_exechdr *exechdrp;
65 	struct ecoff_symhdr *symhdrp;
66 	struct ecoff_extsym *esyms;
67 	struct stat st;
68 	char *mappedfile;
69 	size_t mappedsize;
70 	u_long symhdroff, extstroff;
71 	u_int symhdrsize;
72 	int rv, nent;
73 	long i, nesyms;
74 
75 	rv = -1;
76 
77 	/*
78 	 * If we can't fstat() the file, something bad is going on.
79 	 */
80 	if (fstat(fd, &st) < 0)
81 		BAD;
82 
83 	/*
84 	 * Map the file in its entirety.
85 	 */
86 	if (st.st_size > SIZE_T_MAX) {
87 		errno = EFBIG;
88 		BAD;
89 	}
90 	mappedsize = st.st_size;
91 	mappedfile = mmap(NULL, mappedsize, PROT_READ, 0, fd, 0);
92 	if (mappedfile == (char *)-1)
93 		BAD;
94 
95 	/*
96 	 * Make sure we can access the executable's header
97 	 * directly, and make sure the recognize the executable
98 	 * as an ECOFF binary.
99 	 */
100 	if (check(0, sizeof *exechdrp))
101 		BADUNMAP;
102 	exechdrp = (struct ecoff_exechdr *)&mappedfile[0];
103 
104 	if (ECOFF_BADMAG(exechdrp))
105 		BADUNMAP;
106 
107 	/*
108 	 * Find the symbol list.
109 	 */
110 	symhdroff = exechdrp->f.f_symptr;
111 	symhdrsize = exechdrp->f.f_nsyms;
112 
113 	if (check(symhdroff, sizeof *symhdrp) ||
114 	    sizeof *symhdrp != symhdrsize)
115 		BADUNMAP;
116 	symhdrp = (struct ecoff_symhdr *)&mappedfile[symhdroff];
117 
118 	nesyms = symhdrp->esymMax;
119 	if (check(symhdrp->cbExtOffset, nesyms * sizeof *esyms))
120 		BADUNMAP;
121 	esyms = (struct ecoff_extsym *)&mappedfile[symhdrp->cbExtOffset];
122 	extstroff = symhdrp->cbSsExtOffset;
123 
124 	/*
125 	 * Clean out any left-over information for all valid entries.
126 	 * Type and value are defined to be 0 if not found; historical
127 	 * versions cleared other and desc as well.
128 	 *
129 	 * XXX Clearing anything other than n_type and n_value violates
130 	 * the semantics given in the man page.
131 	 */
132 	nent = 0;
133 	for (p = list; !ISLAST(p); ++p) {
134 		p->n_type = 0;
135 		p->n_other = 0;
136 		p->n_desc = 0;
137 		p->n_value = 0;
138 		++nent;
139 	}
140 
141 	for (i = 0; i < nesyms; i++) {
142 		for (p = list; !ISLAST(p); p++) {
143 			char *nlistname;
144 			char *symtabname;
145 
146 			/* This may be incorrect */
147 			nlistname = p->n_un.n_name;
148 			if (*nlistname == '_')
149 				nlistname++;
150 
151 			symtabname =
152 			    &mappedfile[extstroff + esyms[i].es_strindex];
153 
154 			if (!strcmp(symtabname, nlistname)) {
155 				/*
156 				 * Translate (roughly) from ECOFF to nlist
157 				 */
158 				p->n_value = esyms[i].es_value;
159 				p->n_type = N_EXT;		/* XXX */
160 				p->n_desc = 0;			/* XXX */
161 				p->n_other = 0;			/* XXX */
162 
163 				if (--nent <= 0)
164 					goto done;
165 				break;	/* into next run of outer loop */
166 			}
167 		}
168 	}
169 
170 done:
171 	rv = nent;
172 unmap:
173 	munmap(mappedfile, mappedsize);
174 out:
175 	return (rv);
176 }
177 
178 #endif /* NLIST_ECOFF */
179