xref: /freebsd/sys/i386/linux/imgact_linux.c (revision ede8dc43a2624d29d33de0a0bbdd0990d978b7c3)
1 /*-
2  * Copyright (c) 1994-1996 S�ren Schmidt
3  * All rights reserved.
4  *
5  * Based heavily on /sys/kern/imgact_aout.c which is:
6  * Copyright (c) 1993, David Greenman
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer
13  *    in this position and unchanged.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. The name of the author may not be used to endorse or promote products
18  *    derived from this software withough specific prior written permission
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  *
31  *	$Id: imgact_linux.c,v 1.12 1996/03/12 06:20:16 peter 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 #include <vm/vm_kern.h>
46 #include <vm/vm_param.h>
47 #include <vm/pmap.h>
48 #include <vm/lock.h>
49 #include <vm/vm_map.h>
50 #include <vm/vm_prot.h>
51 #include <vm/vm_extern.h>
52 
53 #include <i386/linux/linux.h>
54 #include <i386/linux/linux_proto.h>
55 
56 extern int	exec_linux_imgact __P((struct image_params *iparams));
57 
58 int
59 exec_linux_imgact(imgp)
60     struct image_params *imgp;
61 {
62     struct exec *a_out = (struct exec *) imgp->image_header;
63     struct vmspace *vmspace = imgp->proc->p_vmspace;
64     vm_offset_t vmaddr;
65     unsigned long virtual_offset, file_offset;
66     vm_offset_t buffer;
67     unsigned long bss_size;
68     int error;
69 
70     if (((a_out->a_magic >> 16) & 0xff) != 0x64)
71 	return -1;
72 
73     /*
74      * Set file/virtual offset based on a.out variant.
75      */
76     switch ((int)(a_out->a_magic & 0xffff)) {
77     case 0413:
78 	virtual_offset = 0;
79 	file_offset = 1024;
80 	break;
81     case 0314:
82 	virtual_offset = 4096;
83 	file_offset = 0;
84 	break;
85     default:
86 	return (-1);
87     }
88     bss_size = round_page(a_out->a_bss);
89 #ifdef DEBUG
90     printf("imgact: text: %08x, data: %08x, bss: %08x\n", a_out->a_text, a_out->a_data, bss_size);
91 #endif
92 
93     /*
94      * Check various fields in header for validity/bounds.
95      */
96     if (a_out->a_entry < virtual_offset ||
97 	a_out->a_entry >= virtual_offset + a_out->a_text ||
98 	a_out->a_text % NBPG || a_out->a_data % NBPG)
99 	return (-1);
100 
101     /* text + data can't exceed file size */
102     if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
103 	return (EFAULT);
104     /*
105      * text/data/bss must not exceed limits
106      */
107     if (a_out->a_text > MAXTSIZ || a_out->a_data + bss_size > MAXDSIZ ||
108 	a_out->a_data+bss_size > imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur)
109 	return (ENOMEM);
110 
111     /* copy in arguments and/or environment from old process */
112     error = exec_extract_strings(imgp);
113     if (error)
114 	return (error);
115 
116     /*
117      * Destroy old process VM and create a new one (with a new stack)
118      */
119     exec_new_vmspace(imgp);
120 
121     /*
122      * Check if file_offset page aligned,.
123      * Currently we cannot handle misalinged file offsets,
124      * and so we read in the entire image (what a waste).
125      */
126     if (file_offset & PGOFSET) {
127 #ifdef DEBUG
128 	printf("imgact: Non page aligned binary %d\n", file_offset);
129 #endif
130 	/*
131 	 * Map text+data+bss read/write/execute
132 	 */
133 	vmaddr = virtual_offset;
134 	error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr,
135 		    	    a_out->a_text + a_out->a_data + bss_size, FALSE,
136 			    VM_PROT_ALL, VM_PROT_ALL, 0);
137 	if (error)
138 	    return error;
139 
140 	error = vm_mmap(kernel_map, &buffer,
141 			round_page(a_out->a_text + a_out->a_data + file_offset),
142 			VM_PROT_READ, VM_PROT_READ, 0,
143 			(caddr_t) imgp->vp, trunc_page(file_offset));
144 	if (error)
145 	    return error;
146 
147 	error = copyout((caddr_t)(buffer + file_offset), (caddr_t)vmaddr,
148 			a_out->a_text + a_out->a_data);
149 
150 	vm_map_remove(kernel_map, buffer,
151 		      buffer + round_page(a_out->a_text + a_out->a_data + file_offset));
152 
153 	if (error)
154 	    return error;
155 
156 	/*
157 	 * remove write enable on the 'text' part
158 	 */
159 	error = vm_map_protect(&vmspace->vm_map,
160 			       vmaddr,
161 		   	       vmaddr + a_out->a_text,
162 		   	       VM_PROT_EXECUTE|VM_PROT_READ,
163 		   	       TRUE);
164 	if (error)
165 	    return error;
166     }
167     else {
168 #ifdef DEBUG
169 	printf("imgact: Page aligned binary %d\n", file_offset);
170 #endif
171 	/*
172 	 * Map text+data read/execute
173 	 */
174 	vmaddr = virtual_offset;
175 	error = vm_mmap(&vmspace->vm_map, &vmaddr,
176 			a_out->a_text + a_out->a_data,
177 	    		VM_PROT_READ | VM_PROT_EXECUTE,
178 	    		VM_PROT_ALL,
179 	    		MAP_PRIVATE | MAP_FIXED,
180 	    		(caddr_t)imgp->vp, file_offset);
181 	if (error)
182 	    return (error);
183 
184 #ifdef DEBUG
185 	printf("imgact: startaddr=%08x, length=%08x\n", vmaddr, a_out->a_text + a_out->a_data);
186 #endif
187 	/*
188 	 * allow read/write of data
189 	 */
190 	error = vm_map_protect(&vmspace->vm_map,
191 			       vmaddr + a_out->a_text,
192 			       vmaddr + a_out->a_text + a_out->a_data,
193 			       VM_PROT_ALL,
194 			       FALSE);
195 	if (error)
196 	    return (error);
197 
198 	/*
199 	 * Allocate anon demand-zeroed area for uninitialized data
200 	 */
201 	if (bss_size != 0) {
202 	    vmaddr = virtual_offset + a_out->a_text + a_out->a_data;
203 	    error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr,
204 				bss_size, FALSE, VM_PROT_ALL, VM_PROT_ALL, 0);
205 	    if (error)
206 		return (error);
207 #ifdef DEBUG
208 	    printf("imgact: bssaddr=%08x, length=%08x\n", vmaddr, bss_size);
209 #endif
210 
211 	}
212 	/* Indicate that this file should not be modified */
213 	imgp->vp->v_flag |= VTEXT;
214     }
215     /* Fill in process VM information */
216     vmspace->vm_tsize = round_page(a_out->a_text) >> PAGE_SHIFT;
217     vmspace->vm_dsize = round_page(a_out->a_data + bss_size) >> PAGE_SHIFT;
218     vmspace->vm_taddr = (caddr_t)virtual_offset;
219     vmspace->vm_daddr = (caddr_t)virtual_offset + a_out->a_text;
220 
221     /* Fill in image_params */
222     imgp->interpreted = 0;
223     imgp->entry_addr = a_out->a_entry;
224 
225     imgp->proc->p_sysent = &linux_sysvec;
226     return (0);
227 }
228 
229 /*
230  * Tell kern_execve.c about it, with a little help from the linker.
231  * Since `const' objects end up in the text segment, TEXT_SET is the
232  * correct directive to use.
233  */
234 const struct execsw linux_execsw = { exec_linux_imgact, "linux a.out" };
235 TEXT_SET(execsw_set, linux_execsw);
236 
237