xref: /freebsd/sys/kern/imgact_aout.c (revision 0c43d89a0d8e976ca494d4837f4c1f3734d2c300)
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 1.6 1994/08/18 22:34:55 wollman 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 #include <sys/sysent.h>
42 
43 #include <vm/vm.h>
44 
45 int
46 exec_aout_imgact(iparams)
47 	struct image_params *iparams;
48 {
49 	struct exec *a_out = (struct exec *) iparams->image_header;
50 	struct vmspace *vmspace = iparams->proc->p_vmspace;
51 	unsigned long vmaddr, virtual_offset, file_offset;
52 	unsigned long bss_size;
53 	int error, len;
54 	extern struct sysentvec aout_sysvec;
55 
56 	/*
57 	 * Set file/virtual offset based on a.out variant.
58 	 *	We do two cases: host byte order and network byte order
59 	 *	(for NetBSD compatibility)
60 	 */
61 	switch ((int)(a_out->a_magic & 0xffff)) {
62 	case ZMAGIC:
63 		virtual_offset = 0;
64 		if (a_out->a_text) {
65 			file_offset = NBPG;
66 		} else {
67 			/* Bill's "screwball mode" */
68 			file_offset = 0;
69 		}
70 		break;
71 	case QMAGIC:
72 		virtual_offset = NBPG;
73 		file_offset = 0;
74 		break;
75 	default:
76 		/* NetBSD compatibility */
77 		switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
78 		case ZMAGIC:
79 		case QMAGIC:
80 			virtual_offset = NBPG;
81 			file_offset = 0;
82 			break;
83 		default:
84 			return (-1);
85 		}
86 	}
87 
88 	bss_size = roundup(a_out->a_bss, NBPG);
89 
90 	/*
91 	 * Check various fields in header for validity/bounds.
92 	 */
93 	if (/* entry point must lay with text region */
94 	    a_out->a_entry < virtual_offset ||
95 	    a_out->a_entry >= virtual_offset + a_out->a_text ||
96 
97 	    /* text and data size must each be page rounded */
98 	    a_out->a_text % NBPG ||
99 	    a_out->a_data % NBPG)
100 		return (-1);
101 
102 	/* text + data can't exceed file size */
103 	if (a_out->a_data + a_out->a_text > iparams->attr->va_size)
104 		return (EFAULT);
105 
106 	/*
107 	 * text/data/bss must not exceed limits
108 	 */
109 	if (/* text can't exceed maximum text size */
110 	    a_out->a_text > MAXTSIZ ||
111 
112 	    /* data + bss can't exceed maximum data size */
113 	    a_out->a_data + bss_size > MAXDSIZ ||
114 
115 	    /* data + bss can't exceed rlimit */
116 	    a_out->a_data + bss_size >
117 		iparams->proc->p_rlimit[RLIMIT_DATA].rlim_cur)
118 			return (ENOMEM);
119 
120 	/* copy in arguments and/or environment from old process */
121 	error = exec_extract_strings(iparams);
122 	if (error)
123 		return (error);
124 
125 	/*
126 	 * Destroy old process VM and create a new one (with a new stack)
127 	 */
128 	exec_new_vmspace(iparams);
129 
130 	/*
131 	 * Map text read/execute
132 	 */
133 	vmaddr = virtual_offset;
134 	error =
135 	    vm_mmap(&vmspace->vm_map,			/* map */
136 		&vmaddr,				/* address */
137 		a_out->a_text,				/* size */
138 		VM_PROT_READ | VM_PROT_EXECUTE,		/* protection */
139 		VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_WRITE,	/* max protection */
140 		MAP_PRIVATE | MAP_FIXED,		/* flags */
141 		(caddr_t)iparams->vnodep,		/* vnode */
142 		file_offset);				/* offset */
143 	if (error)
144 		return (error);
145 
146 	/*
147 	 * Map data read/write (if text is 0, assume text is in data area
148 	 *	[Bill's screwball mode])
149 	 */
150 	vmaddr = virtual_offset + a_out->a_text;
151 	error =
152 	    vm_mmap(&vmspace->vm_map,
153 		&vmaddr,
154 		a_out->a_data,
155 		VM_PROT_READ | VM_PROT_WRITE | (a_out->a_text ? 0 : VM_PROT_EXECUTE),
156 		VM_PROT_ALL, MAP_PRIVATE | MAP_FIXED,
157 		(caddr_t) iparams->vnodep,
158 		file_offset + a_out->a_text);
159 	if (error)
160 		return (error);
161 
162 	/*
163 	 * Allocate demand-zeroed area for uninitialized data
164 	 * "bss" = 'block started by symbol' - named after the IBM 7090
165 	 *	instruction of the same name.
166 	 */
167 	vmaddr = virtual_offset + a_out->a_text + a_out->a_data;
168 	error = vm_allocate(&vmspace->vm_map, &vmaddr, bss_size, FALSE);
169 	if (error)
170 		return (error);
171 
172 	/* Fill in process VM information */
173 	vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
174 	vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
175 	vmspace->vm_taddr = (caddr_t) virtual_offset;
176 	vmspace->vm_daddr = (caddr_t) virtual_offset + a_out->a_text;
177 
178 	/* Fill in image_params */
179 	iparams->interpreted = 0;
180 	iparams->entry_addr = a_out->a_entry;
181 
182 	iparams->proc->p_sysent = &aout_sysvec;
183 	return (0);
184 }
185 
186 /*
187  * Tell kern_execve.c about it, with a little help from the linker.
188  * Since `const' objects end up in the text segment, TEXT_SET is the
189  * correct directive to use.
190  */
191 static const struct execsw aout_execsw = { exec_aout_imgact, "a.out" };
192 TEXT_SET(execsw_set, aout_execsw);
193 
194