xref: /netbsd-src/sys/compat/freebsd/freebsd_exec_elf32.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
1 /*	$NetBSD: freebsd_exec_elf32.c,v 1.2 2001/07/14 02:05:05 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1993, 1994 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *      This product includes software developed by Christopher G. Demetriou.
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 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/proc.h>
36 #include <sys/malloc.h>
37 #include <sys/vnode.h>
38 #include <sys/exec.h>
39 #ifndef ELFSIZE
40 #  define ELFSIZE 32
41 #endif /* !ELFSIZE */
42 #include <sys/exec_elf.h>
43 
44 #include <machine/freebsd_machdep.h>
45 
46 #include <compat/freebsd/freebsd_exec.h>
47 #include <compat/common/compat_util.h>
48 
49 int
50 ELFNAME2(freebsd,probe)(p, epp, veh, itp, pos)
51 	struct proc *p;
52 	struct exec_package *epp;
53 	void *veh;
54 	char *itp;
55 	vaddr_t *pos;
56 {
57 	int error;
58 	size_t i;
59 	size_t phsize;
60 	Elf_Ehdr *eh = (Elf_Ehdr *) veh;
61 	Elf_Phdr *ph;
62 	Elf_Phdr *ephp;
63 	Elf_Nhdr *np;
64 	const char *bp;
65 
66         static const char wantBrand[] = FREEBSD_ELF_BRAND_STRING;
67         static const char wantInterp[] = FREEBSD_ELF_INTERP_PREFIX_STRING;
68 
69         /* Insist that the executable have a brand, and that it be "FreeBSD" */
70 #ifndef EI_BRAND
71 #define EI_BRAND 8
72 #endif
73         if (eh->e_ident[EI_BRAND] == '\0'
74 	  || strcmp(&eh->e_ident[EI_BRAND], wantBrand))
75 		return ENOEXEC;
76 
77 	i = eh->e_phnum;
78 	if (i != 0) {
79 		phsize = i * sizeof(Elf_Phdr);
80 		ph = (Elf_Phdr *) malloc(phsize, M_TEMP, M_WAITOK);
81 		if ((error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph,
82 		    phsize)) != 0)
83 			goto bad1;
84 
85 		for (ephp = ph; i--; ephp++) {
86 			if (ephp->p_type != PT_INTERP)
87 				continue;
88 
89 			/* Check for "legal" intepreter name. */
90 			if (ephp->p_filesz < sizeof wantInterp)
91 				goto bad1;
92 
93 			np = (Elf_Nhdr *) malloc(ephp->p_filesz+1,
94 			    M_TEMP, M_WAITOK);
95 
96 			if (((error = exec_read_from(p, epp->ep_vp,
97 			    ephp->p_offset, np, ephp->p_filesz)) != 0))
98 				goto bad2;
99 
100 			if (strncmp((char *)np, wantInterp,
101 			    sizeof wantInterp - 1))
102 				goto bad2;
103 
104 			free(np, M_TEMP);
105 			break;
106 		}
107 		free(ph, M_TEMP);
108 	}
109 
110 	if (itp[0]) {
111 		if ((error = emul_find(p, NULL, epp->ep_esch->es_emul->e_path,
112 		    itp, &bp, 0)))
113 			return error;
114 		if ((error = copystr(bp, itp, MAXPATHLEN, &i)) != 0)
115 			return error;
116 		free((void *)bp, M_TEMP);
117 	}
118 	*pos = ELF_NO_ADDR;
119 #ifdef DEBUG_FREEBSD_ELF
120 	printf("freebsd_elf32_probe: returning 0\n");
121 #endif
122 	return 0;
123 
124 bad2:
125 	free(np, M_TEMP);
126 bad1:
127 	free(ph, M_TEMP);
128 	return ENOEXEC;
129 }
130