xref: /freebsd/sys/i386/linux/imgact_linux.c (revision e627b39baccd1ec9129690167cf5e6d860509655)
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 1.15 1996/05/02 10:43:12 phk 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/proc.h>
43 #include <sys/sysent.h>
44 #include <sys/vnode.h>
45 
46 #include <vm/vm.h>
47 #include <vm/vm_kern.h>
48 #include <vm/vm_param.h>
49 #include <vm/pmap.h>
50 #include <vm/lock.h>
51 #include <vm/vm_map.h>
52 #include <vm/vm_prot.h>
53 #include <vm/vm_extern.h>
54 
55 #include <i386/linux/linux.h>
56 #include <i386/linux/linux_proto.h>
57 
58 extern int	exec_linux_imgact __P((struct image_params *iparams));
59 
60 int
61 exec_linux_imgact(imgp)
62     struct image_params *imgp;
63 {
64     const struct exec *a_out = (const struct exec *) imgp->image_header;
65     struct vmspace *vmspace = imgp->proc->p_vmspace;
66     vm_offset_t vmaddr;
67     unsigned long virtual_offset, file_offset;
68     vm_offset_t buffer;
69     unsigned long bss_size;
70     int error;
71 
72     if (((a_out->a_magic >> 16) & 0xff) != 0x64)
73 	return -1;
74 
75     /*
76      * Set file/virtual offset based on a.out variant.
77      */
78     switch ((int)(a_out->a_magic & 0xffff)) {
79     case 0413:
80 	virtual_offset = 0;
81 	file_offset = 1024;
82 	break;
83     case 0314:
84 	virtual_offset = 4096;
85 	file_offset = 0;
86 	break;
87     default:
88 	return (-1);
89     }
90     bss_size = round_page(a_out->a_bss);
91 #ifdef DEBUG
92     printf("imgact: text: %08x, data: %08x, bss: %08x\n", a_out->a_text, a_out->a_data, bss_size);
93 #endif
94 
95     /*
96      * Check various fields in header for validity/bounds.
97      */
98     if (a_out->a_entry < virtual_offset ||
99 	a_out->a_entry >= virtual_offset + a_out->a_text ||
100 	a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK)
101 	return (-1);
102 
103     /* text + data can't exceed file size */
104     if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
105 	return (EFAULT);
106     /*
107      * text/data/bss must not exceed limits
108      */
109     if (a_out->a_text > MAXTSIZ || a_out->a_data + bss_size > MAXDSIZ ||
110 	a_out->a_data+bss_size > imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur)
111 	return (ENOMEM);
112 
113     /* copy in arguments and/or environment from old process */
114     error = exec_extract_strings(imgp);
115     if (error)
116 	return (error);
117 
118     /*
119      * Destroy old process VM and create a new one (with a new stack)
120      */
121     exec_new_vmspace(imgp);
122 
123     /*
124      * Check if file_offset page aligned,.
125      * Currently we cannot handle misalinged file offsets,
126      * and so we read in the entire image (what a waste).
127      */
128     if (file_offset & PAGE_MASK) {
129 #ifdef DEBUG
130 	printf("imgact: Non page aligned binary %d\n", file_offset);
131 #endif
132 	/*
133 	 * Map text+data+bss read/write/execute
134 	 */
135 	vmaddr = virtual_offset;
136 	error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr,
137 		    	    a_out->a_text + a_out->a_data + bss_size, FALSE,
138 			    VM_PROT_ALL, VM_PROT_ALL, 0);
139 	if (error)
140 	    return error;
141 
142 	error = vm_mmap(kernel_map, &buffer,
143 			round_page(a_out->a_text + a_out->a_data + file_offset),
144 			VM_PROT_READ, VM_PROT_READ, 0,
145 			(caddr_t) imgp->vp, trunc_page(file_offset));
146 	if (error)
147 	    return error;
148 
149 	error = copyout((caddr_t)(buffer + file_offset), (caddr_t)vmaddr,
150 			a_out->a_text + a_out->a_data);
151 
152 	vm_map_remove(kernel_map, buffer,
153 		      buffer + round_page(a_out->a_text + a_out->a_data + file_offset));
154 
155 	if (error)
156 	    return error;
157 
158 	/*
159 	 * remove write enable on the 'text' part
160 	 */
161 	error = vm_map_protect(&vmspace->vm_map,
162 			       vmaddr,
163 		   	       vmaddr + a_out->a_text,
164 		   	       VM_PROT_EXECUTE|VM_PROT_READ,
165 		   	       TRUE);
166 	if (error)
167 	    return error;
168     }
169     else {
170 #ifdef DEBUG
171 	printf("imgact: Page aligned binary %d\n", file_offset);
172 #endif
173 	/*
174 	 * Map text+data read/execute
175 	 */
176 	vmaddr = virtual_offset;
177 	error = vm_mmap(&vmspace->vm_map, &vmaddr,
178 			a_out->a_text + a_out->a_data,
179 	    		VM_PROT_READ | VM_PROT_EXECUTE,
180 	    		VM_PROT_ALL,
181 	    		MAP_PRIVATE | MAP_FIXED,
182 	    		(caddr_t)imgp->vp, file_offset);
183 	if (error)
184 	    return (error);
185 
186 #ifdef DEBUG
187 	printf("imgact: startaddr=%08x, length=%08x\n", vmaddr, a_out->a_text + a_out->a_data);
188 #endif
189 	/*
190 	 * allow read/write of data
191 	 */
192 	error = vm_map_protect(&vmspace->vm_map,
193 			       vmaddr + a_out->a_text,
194 			       vmaddr + a_out->a_text + a_out->a_data,
195 			       VM_PROT_ALL,
196 			       FALSE);
197 	if (error)
198 	    return (error);
199 
200 	/*
201 	 * Allocate anon demand-zeroed area for uninitialized data
202 	 */
203 	if (bss_size != 0) {
204 	    vmaddr = virtual_offset + a_out->a_text + a_out->a_data;
205 	    error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr,
206 				bss_size, FALSE, VM_PROT_ALL, VM_PROT_ALL, 0);
207 	    if (error)
208 		return (error);
209 #ifdef DEBUG
210 	    printf("imgact: bssaddr=%08x, length=%08x\n", vmaddr, bss_size);
211 #endif
212 
213 	}
214 	/* Indicate that this file should not be modified */
215 	imgp->vp->v_flag |= VTEXT;
216     }
217     /* Fill in process VM information */
218     vmspace->vm_tsize = round_page(a_out->a_text) >> PAGE_SHIFT;
219     vmspace->vm_dsize = round_page(a_out->a_data + bss_size) >> PAGE_SHIFT;
220     vmspace->vm_taddr = (caddr_t)virtual_offset;
221     vmspace->vm_daddr = (caddr_t)virtual_offset + a_out->a_text;
222 
223     /* Fill in image_params */
224     imgp->interpreted = 0;
225     imgp->entry_addr = a_out->a_entry;
226 
227     imgp->proc->p_sysent = &linux_sysvec;
228     return (0);
229 }
230 
231 /*
232  * Tell kern_execve.c about it, with a little help from the linker.
233  * Since `const' objects end up in the text segment, TEXT_SET is the
234  * correct directive to use.
235  */
236 const struct execsw linux_execsw = { exec_linux_imgact, "linux a.out" };
237 TEXT_SET(execsw_set, linux_execsw);
238 
239