xref: /freebsd/sys/kern/imgact_aout.c (revision 23f282aa31e9b6fceacd449020e936e98d6f2298)
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  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <sys/param.h>
30 #include <sys/resourcevar.h>
31 #include <sys/exec.h>
32 #include <sys/fcntl.h>
33 #include <sys/imgact.h>
34 #include <sys/imgact_aout.h>
35 #include <sys/kernel.h>
36 #include <sys/namei.h>
37 #include <sys/pioctl.h>
38 #include <sys/proc.h>
39 #include <sys/signalvar.h>
40 #include <sys/stat.h>
41 #include <sys/sysent.h>
42 #include <sys/syscall.h>
43 #include <sys/vnode.h>
44 #include <sys/systm.h>
45 #include <machine/md_var.h>
46 
47 #include <vm/vm.h>
48 #include <vm/vm_param.h>
49 #include <sys/lock.h>
50 #include <vm/pmap.h>
51 #include <vm/vm_map.h>
52 #include <vm/vm_object.h>
53 #include <sys/user.h>
54 
55 static int	exec_aout_imgact __P((struct image_params *imgp));
56 
57 struct sysentvec aout_sysvec = {
58 	SYS_MAXSYSCALL,
59 	sysent,
60 	0,
61 	0,
62 	0,
63 	0,
64 	0,
65 	0,
66 	0,
67 	sendsig,
68 	sigcode,
69 	&szsigcode,
70 	0,
71 	"FreeBSD a.out",
72 	aout_coredump
73 };
74 
75 static int
76 exec_aout_imgact(imgp)
77 	struct image_params *imgp;
78 {
79 	const struct exec *a_out = (const struct exec *) imgp->image_header;
80 	struct vmspace *vmspace;
81 	struct vnode *vp;
82 	vm_map_t map;
83 	vm_object_t object;
84 	vm_offset_t text_end, data_end;
85 	unsigned long virtual_offset;
86 	unsigned long file_offset;
87 	unsigned long bss_size;
88 	int error;
89 
90 	/*
91 	 * Linux and *BSD binaries look very much alike,
92 	 * only the machine id is different:
93 	 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
94 	 * NetBSD is in network byte order.. ugh.
95 	 */
96 	if (((a_out->a_magic >> 16) & 0xff) != 0x86 &&
97 	    ((a_out->a_magic >> 16) & 0xff) != 0 &&
98 	    ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86)
99                 return -1;
100 
101 	/*
102 	 * Set file/virtual offset based on a.out variant.
103 	 *	We do two cases: host byte order and network byte order
104 	 *	(for NetBSD compatibility)
105 	 */
106 	switch ((int)(a_out->a_magic & 0xffff)) {
107 	case ZMAGIC:
108 		virtual_offset = 0;
109 		if (a_out->a_text) {
110 			file_offset = PAGE_SIZE;
111 		} else {
112 			/* Bill's "screwball mode" */
113 			file_offset = 0;
114 		}
115 		break;
116 	case QMAGIC:
117 		virtual_offset = PAGE_SIZE;
118 		file_offset = 0;
119 		/* Pass PS_STRINGS for BSD/OS binaries only. */
120 		if (N_GETMID(*a_out) == MID_ZERO)
121 			imgp->ps_strings = PS_STRINGS;
122 		break;
123 	default:
124 		/* NetBSD compatibility */
125 		switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
126 		case ZMAGIC:
127 		case QMAGIC:
128 			virtual_offset = PAGE_SIZE;
129 			file_offset = 0;
130 			break;
131 		default:
132 			return (-1);
133 		}
134 	}
135 
136 	bss_size = roundup(a_out->a_bss, PAGE_SIZE);
137 
138 	/*
139 	 * Check various fields in header for validity/bounds.
140 	 */
141 	if (/* entry point must lay with text region */
142 	    a_out->a_entry < virtual_offset ||
143 	    a_out->a_entry >= virtual_offset + a_out->a_text ||
144 
145 	    /* text and data size must each be page rounded */
146 	    a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK)
147 		return (-1);
148 
149 	/* text + data can't exceed file size */
150 	if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
151 		return (EFAULT);
152 
153 	/*
154 	 * text/data/bss must not exceed limits
155 	 */
156 	if (/* text can't exceed maximum text size */
157 	    a_out->a_text > MAXTSIZ ||
158 
159 	    /* data + bss can't exceed rlimit */
160 	    a_out->a_data + bss_size >
161 		imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur)
162 			return (ENOMEM);
163 
164 	/* copy in arguments and/or environment from old process */
165 	error = exec_extract_strings(imgp);
166 	if (error)
167 		return (error);
168 
169 	/*
170 	 * Destroy old process VM and create a new one (with a new stack)
171 	 */
172 	exec_new_vmspace(imgp);
173 
174 	/*
175 	 * The vm space can be changed by exec_new_vmspace
176 	 */
177 	vmspace = imgp->proc->p_vmspace;
178 
179 	vp = imgp->vp;
180 	map = &vmspace->vm_map;
181 	vm_map_lock(map);
182 	object = vp->v_object;
183 	vm_object_reference(object);
184 
185 	text_end = virtual_offset + a_out->a_text;
186 	error = vm_map_insert(map, object,
187 		file_offset,
188 		virtual_offset, text_end,
189 		VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
190 		MAP_COPY_ON_WRITE | MAP_PREFAULT);
191 	if (error) {
192 		vm_map_unlock(map);
193 		return (error);
194 	}
195 	data_end = text_end + a_out->a_data;
196 	if (a_out->a_data) {
197 		vm_object_reference(object);
198 		error = vm_map_insert(map, object,
199 			file_offset + a_out->a_text,
200 			text_end, data_end,
201 			VM_PROT_ALL, VM_PROT_ALL,
202 			MAP_COPY_ON_WRITE | MAP_PREFAULT);
203 		if (error) {
204 			vm_map_unlock(map);
205 			return (error);
206 		}
207 	}
208 
209 	if (bss_size) {
210 		error = vm_map_insert(map, NULL, 0,
211 			data_end, data_end + bss_size,
212 			VM_PROT_ALL, VM_PROT_ALL, 0);
213 		if (error) {
214 			vm_map_unlock(map);
215 			return (error);
216 		}
217 	}
218 	vm_map_unlock(map);
219 
220 	/* Fill in process VM information */
221 	vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
222 	vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
223 	vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset;
224 	vmspace->vm_daddr = (caddr_t) (uintptr_t)
225 			    (virtual_offset + a_out->a_text);
226 
227 	/* Fill in image_params */
228 	imgp->interpreted = 0;
229 	imgp->entry_addr = a_out->a_entry;
230 
231 	imgp->proc->p_sysent = &aout_sysvec;
232 
233 	/* Indicate that this file should not be modified */
234 	imgp->vp->v_flag |= VTEXT;
235 
236 	return (0);
237 }
238 
239 /*
240  * Dump core, into a file named as described in the comments for
241  * expand_name(), unless the process was setuid/setgid.
242  */
243 int
244 aout_coredump(p, vp, limit)
245 	register struct proc *p;
246 	register struct vnode *vp;
247 	off_t limit;
248 {
249 	register struct ucred *cred = p->p_ucred;
250 	register struct vmspace *vm = p->p_vmspace;
251 	int error;
252 
253 	if (ctob(UPAGES + vm->vm_dsize + vm->vm_ssize) >= limit)
254 		return (EFAULT);
255 	bcopy(p, &p->p_addr->u_kproc.kp_proc, sizeof(struct proc));
256 	fill_eproc(p, &p->p_addr->u_kproc.kp_eproc);
257 	error = cpu_coredump(p, vp, cred);
258 	if (error == 0)
259 		error = vn_rdwr(UIO_WRITE, vp, vm->vm_daddr,
260 		    (int)ctob(vm->vm_dsize), (off_t)ctob(UPAGES), UIO_USERSPACE,
261 		    IO_NODELOCKED|IO_UNIT, cred, (int *) NULL, p);
262 	if (error == 0)
263 		error = vn_rdwr(UIO_WRITE, vp,
264 		    (caddr_t) trunc_page(USRSTACK - ctob(vm->vm_ssize)),
265 		    round_page(ctob(vm->vm_ssize)),
266 		    (off_t)ctob(UPAGES) + ctob(vm->vm_dsize), UIO_USERSPACE,
267 		    IO_NODELOCKED|IO_UNIT, cred, (int *) NULL, p);
268 	return (error);
269 }
270 
271 /*
272  * Tell kern_execve.c about it, with a little help from the linker.
273  */
274 static struct execsw aout_execsw = { exec_aout_imgact, "a.out" };
275 EXEC_SET(aout, aout_execsw);
276