xref: /freebsd/sys/kern/imgact_aout.c (revision a316b26e50bbed7cf655fbba726ab87d8ab7599d)
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 1.8 1994/09/24 21:36:50 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/imgact_aout.h>
41 #include <sys/kernel.h>
42 #include <sys/sysent.h>
43 
44 #include <vm/vm.h>
45 
46 int
47 exec_aout_imgact(iparams)
48 	struct image_params *iparams;
49 {
50 	struct exec *a_out = (struct exec *) iparams->image_header;
51 	struct vmspace *vmspace = iparams->proc->p_vmspace;
52 	unsigned long vmaddr, virtual_offset, file_offset;
53 	unsigned long bss_size;
54 	int error;
55 	extern struct sysentvec aout_sysvec;
56 
57 	/*
58 	 * Set file/virtual offset based on a.out variant.
59 	 *	We do two cases: host byte order and network byte order
60 	 *	(for NetBSD compatibility)
61 	 */
62 	switch ((int)(a_out->a_magic & 0xffff)) {
63 	case ZMAGIC:
64 		virtual_offset = 0;
65 		if (a_out->a_text) {
66 			file_offset = NBPG;
67 		} else {
68 			/* Bill's "screwball mode" */
69 			file_offset = 0;
70 		}
71 		break;
72 	case QMAGIC:
73 		virtual_offset = NBPG;
74 		file_offset = 0;
75 		break;
76 	default:
77 		/* NetBSD compatibility */
78 		switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
79 		case ZMAGIC:
80 		case QMAGIC:
81 			virtual_offset = NBPG;
82 			file_offset = 0;
83 			break;
84 		default:
85 			return (-1);
86 		}
87 	}
88 
89 	bss_size = roundup(a_out->a_bss, NBPG);
90 
91 	/*
92 	 * Check various fields in header for validity/bounds.
93 	 */
94 	if (/* entry point must lay with text region */
95 	    a_out->a_entry < virtual_offset ||
96 	    a_out->a_entry >= virtual_offset + a_out->a_text ||
97 
98 	    /* text and data size must each be page rounded */
99 	    a_out->a_text % NBPG ||
100 	    a_out->a_data % NBPG)
101 		return (-1);
102 
103 	/* text + data can't exceed file size */
104 	if (a_out->a_data + a_out->a_text > iparams->attr->va_size)
105 		return (EFAULT);
106 
107 	/*
108 	 * text/data/bss must not exceed limits
109 	 */
110 	if (/* text can't exceed maximum text size */
111 	    a_out->a_text > MAXTSIZ ||
112 
113 	    /* data + bss can't exceed maximum data size */
114 	    a_out->a_data + bss_size > MAXDSIZ ||
115 
116 	    /* data + bss can't exceed rlimit */
117 	    a_out->a_data + bss_size >
118 		iparams->proc->p_rlimit[RLIMIT_DATA].rlim_cur)
119 			return (ENOMEM);
120 
121 	/* copy in arguments and/or environment from old process */
122 	error = exec_extract_strings(iparams);
123 	if (error)
124 		return (error);
125 
126 	/*
127 	 * Destroy old process VM and create a new one (with a new stack)
128 	 */
129 	exec_new_vmspace(iparams);
130 
131 	/*
132 	 * Map text read/execute
133 	 */
134 	vmaddr = virtual_offset;
135 	error =
136 	    vm_mmap(&vmspace->vm_map,			/* map */
137 		&vmaddr,				/* address */
138 		a_out->a_text,				/* size */
139 		VM_PROT_READ | VM_PROT_EXECUTE,		/* protection */
140 		VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_WRITE,	/* max protection */
141 		MAP_PRIVATE | MAP_FIXED,		/* flags */
142 		(caddr_t)iparams->vnodep,		/* vnode */
143 		file_offset);				/* offset */
144 	if (error)
145 		return (error);
146 
147 	/*
148 	 * Map data read/write (if text is 0, assume text is in data area
149 	 *	[Bill's screwball mode])
150 	 */
151 	vmaddr = virtual_offset + a_out->a_text;
152 	error =
153 	    vm_mmap(&vmspace->vm_map,
154 		&vmaddr,
155 		a_out->a_data,
156 		VM_PROT_READ | VM_PROT_WRITE | (a_out->a_text ? 0 : VM_PROT_EXECUTE),
157 		VM_PROT_ALL, MAP_PRIVATE | MAP_FIXED,
158 		(caddr_t) iparams->vnodep,
159 		file_offset + a_out->a_text);
160 	if (error)
161 		return (error);
162 
163 	/*
164 	 * Allocate demand-zeroed area for uninitialized data
165 	 * "bss" = 'block started by symbol' - named after the IBM 7090
166 	 *	instruction of the same name.
167 	 */
168 	vmaddr = virtual_offset + a_out->a_text + a_out->a_data;
169 	error = vm_allocate(&vmspace->vm_map, &vmaddr, bss_size, FALSE);
170 	if (error)
171 		return (error);
172 
173 	/* Fill in process VM information */
174 	vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
175 	vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
176 	vmspace->vm_taddr = (caddr_t) virtual_offset;
177 	vmspace->vm_daddr = (caddr_t) virtual_offset + a_out->a_text;
178 
179 	/* Fill in image_params */
180 	iparams->interpreted = 0;
181 	iparams->entry_addr = a_out->a_entry;
182 
183 	iparams->proc->p_sysent = &aout_sysvec;
184 	return (0);
185 }
186 
187 /*
188  * Tell kern_execve.c about it, with a little help from the linker.
189  * Since `const' objects end up in the text segment, TEXT_SET is the
190  * correct directive to use.
191  */
192 static const struct execsw aout_execsw = { exec_aout_imgact, "a.out" };
193 TEXT_SET(execsw_set, aout_execsw);
194 
195