xref: /netbsd-src/usr.sbin/mdsetimage/exec_elf32.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /* $NetBSD: exec_elf32.c,v 1.12 2010/08/28 21:30:03 joerg Exp $ */
2 
3 /*
4  * Copyright (c) 1996 Christopher G. Demetriou
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * <<Id: LICENSE_GC,v 1.1 2001/10/01 23:24:05 cgd Exp>>
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __RCSID("$NetBSD: exec_elf32.c,v 1.12 2010/08/28 21:30:03 joerg Exp $");
35 #endif /* not lint */
36 
37 #ifndef ELFSIZE
38 #define	ELFSIZE		32
39 #endif
40 
41 #include <sys/types.h>
42 #include <stdio.h>
43 #include <string.h>
44 #include "extern.h"
45 
46 #if defined(NLIST_ELF32) || defined(NLIST_ELF64)
47 #include <sys/exec_elf.h>
48 #endif
49 
50 #if (defined(NLIST_ELF32) && (ELFSIZE == 32)) || \
51     (defined(NLIST_ELF64) && (ELFSIZE == 64))
52 
53 #define	check(off, size)	((off < 0) || (off + size > mappedsize))
54 #define	BAD			do { rv = -1; goto out; } while (0)
55 
56 int
57 ELFNAMEEND(check)(mappedfile, mappedsize)
58 	const char *mappedfile;
59 	size_t mappedsize;
60 {
61 	const Elf_Ehdr *ehdrp;
62 	int rv;
63 
64 	rv = 0;
65 
66 	if (check(0, sizeof *ehdrp))
67 		BAD;
68 	ehdrp = (const Elf_Ehdr *)&mappedfile[0];
69 
70 	if (memcmp(ehdrp->e_ident, ELFMAG, SELFMAG) != 0 ||
71 	    ehdrp->e_ident[EI_CLASS] != ELFCLASS)
72 		BAD;
73 
74 	switch (ehdrp->e_machine) {
75 	ELFDEFNNAME(MACHDEP_ID_CASES)
76 
77 	default:
78 		BAD;
79 	}
80 
81 out:
82 	return (rv);
83 }
84 
85 int
86 ELFNAMEEND(findoff)(mappedfile, mappedsize, vmaddr, fileoffp)
87 	const char *mappedfile;
88 	size_t mappedsize, *fileoffp;
89 	u_long vmaddr;
90 {
91 	const Elf_Ehdr *ehdrp;
92 	const Elf_Phdr *phdrp;
93 	Elf_Off phdr_off;
94 	Elf_Word phdr_size;
95 #if (ELFSIZE == 32)
96 	Elf32_Half nphdr, i;
97 #elif (ELFSIZE == 64)
98 	Elf64_Word nphdr, i;
99 #endif
100 	int rv;
101 
102 	rv = 0;
103 
104 	ehdrp = (const Elf_Ehdr *)&mappedfile[0];
105 	nphdr = ehdrp->e_phnum;
106 	phdr_off = ehdrp->e_phoff;
107 	phdr_size = sizeof(Elf_Phdr) * nphdr;
108 
109 	if (check(0, phdr_off + phdr_size))
110 		BAD;
111 	phdrp = (const Elf_Phdr *)&mappedfile[phdr_off];
112 
113 #define IS_TEXT(p)	(p.p_flags & PF_X)
114 #define IS_DATA(p)	(p.p_flags & PF_W)
115 
116 	for (i = 0; i < nphdr; i++) {
117 		if ((IS_TEXT(phdrp[i]) || IS_DATA(phdrp[i])) &&
118 		    phdrp[i].p_vaddr <= vmaddr &&
119 		    vmaddr < phdrp[i].p_vaddr + phdrp[i].p_filesz) {
120 			*fileoffp = vmaddr -
121 			    phdrp[i].p_vaddr + phdrp[i].p_offset;
122 			break;
123 		}
124 	}
125 	if (i == nphdr)
126 		BAD;
127 
128 out:
129 	return (rv);
130 }
131 
132 #endif /* include this size of ELF */
133