xref: /freebsd/sys/kern/imgact_aout.c (revision afe61c15161c324a7af299a9b8457aba5afc92db)
1 /*
2  * Copyright (c) 1993, David Greenman
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by David Greenman
16  * 4. The name of the developer may be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	$Id: imgact_aout.c,v 1.3 1993/12/30 01:39:29 davidg Exp $
32  */
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/resourcevar.h>
37 #include <sys/exec.h>
38 #include <sys/mman.h>
39 #include <sys/imgact.h>
40 #include <sys/kernel.h>
41 
42 #include <vm/vm.h>
43 
44 int
45 exec_aout_imgact(iparams)
46 	struct image_params *iparams;
47 {
48 	struct exec *a_out = (struct exec *) iparams->image_header;
49 	struct vmspace *vmspace = iparams->proc->p_vmspace;
50 	unsigned long vmaddr, virtual_offset, file_offset;
51 	unsigned long bss_size;
52 	int error, len;
53 
54 	/*
55 	 * Set file/virtual offset based on a.out variant.
56 	 *	We do two cases: host byte order and network byte order
57 	 *	(for NetBSD compatibility)
58 	 */
59 	switch ((int)(a_out->a_magic & 0xffff)) {
60 	case ZMAGIC:
61 		virtual_offset = 0;
62 		if (a_out->a_text) {
63 			file_offset = NBPG;
64 		} else {
65 			/* Bill's "screwball mode" */
66 			file_offset = 0;
67 		}
68 		break;
69 	case QMAGIC:
70 		virtual_offset = NBPG;
71 		file_offset = 0;
72 		break;
73 	default:
74 		/* NetBSD compatibility */
75 		switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
76 		case ZMAGIC:
77 		case QMAGIC:
78 			virtual_offset = NBPG;
79 			file_offset = 0;
80 			break;
81 		default:
82 			return (-1);
83 		}
84 	}
85 
86 	bss_size = roundup(a_out->a_bss, NBPG);
87 
88 	/*
89 	 * Check various fields in header for validity/bounds.
90 	 */
91 	if (/* entry point must lay with text region */
92 	    a_out->a_entry < virtual_offset ||
93 	    a_out->a_entry >= virtual_offset + a_out->a_text ||
94 
95 	    /* text and data size must each be page rounded */
96 	    a_out->a_text % NBPG ||
97 	    a_out->a_data % NBPG)
98 		return (-1);
99 
100 	/* text + data can't exceed file size */
101 	if (a_out->a_data + a_out->a_text > iparams->attr->va_size)
102 		return (EFAULT);
103 
104 	/*
105 	 * text/data/bss must not exceed limits
106 	 */
107 	if (/* text can't exceed maximum text size */
108 	    a_out->a_text > MAXTSIZ ||
109 
110 	    /* data + bss can't exceed maximum data size */
111 	    a_out->a_data + bss_size > MAXDSIZ ||
112 
113 	    /* data + bss can't exceed rlimit */
114 	    a_out->a_data + bss_size >
115 		iparams->proc->p_rlimit[RLIMIT_DATA].rlim_cur)
116 			return (ENOMEM);
117 
118 	/* copy in arguments and/or environment from old process */
119 	error = exec_extract_strings(iparams);
120 	if (error)
121 		return (error);
122 
123 	/*
124 	 * Destroy old process VM and create a new one (with a new stack)
125 	 */
126 	exec_new_vmspace(iparams);
127 
128 	/*
129 	 * Map text read/execute
130 	 */
131 	vmaddr = virtual_offset;
132 	error =
133 	    vm_mmap(&vmspace->vm_map,			/* map */
134 		&vmaddr,				/* address */
135 		a_out->a_text,				/* size */
136 		VM_PROT_READ | VM_PROT_EXECUTE,		/* protection */
137 		VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_WRITE,	/* max protection */
138 		MAP_PRIVATE | MAP_FIXED,		/* flags */
139 		(caddr_t)iparams->vnodep,		/* vnode */
140 		file_offset);				/* offset */
141 	if (error)
142 		return (error);
143 
144 	/*
145 	 * Map data read/write (if text is 0, assume text is in data area
146 	 *	[Bill's screwball mode])
147 	 */
148 	vmaddr = virtual_offset + a_out->a_text;
149 	error =
150 	    vm_mmap(&vmspace->vm_map,
151 		&vmaddr,
152 		a_out->a_data,
153 		VM_PROT_READ | VM_PROT_WRITE | (a_out->a_text ? 0 : VM_PROT_EXECUTE),
154 		VM_PROT_ALL, MAP_PRIVATE | MAP_FIXED,
155 		(caddr_t) iparams->vnodep,
156 		file_offset + a_out->a_text);
157 	if (error)
158 		return (error);
159 
160 	/*
161 	 * Allocate demand-zeroed area for uninitialized data
162 	 * "bss" = 'block started by symbol' - named after the IBM 7090
163 	 *	instruction of the same name.
164 	 */
165 	vmaddr = virtual_offset + a_out->a_text + a_out->a_data;
166 	error = vm_allocate(&vmspace->vm_map, &vmaddr, bss_size, FALSE);
167 	if (error)
168 		return (error);
169 
170 	/* Fill in process VM information */
171 	vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
172 	vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
173 	vmspace->vm_taddr = (caddr_t) virtual_offset;
174 	vmspace->vm_daddr = (caddr_t) virtual_offset + a_out->a_text;
175 
176 	/* Fill in image_params */
177 	iparams->interpreted = 0;
178 	iparams->entry_addr = a_out->a_entry;
179 
180 	return (0);
181 }
182 
183 /*
184  * Tell kern_execve.c about it, with a little help from the linker.
185  * Since `const' objects end up in the text segment, TEXT_SET is the
186  * correct directive to use.
187  */
188 static const struct execsw aout_execsw = { exec_aout_imgact };
189 TEXT_SET(execsw_set, aout_execsw);
190 
191