xref: /freebsd/sys/kern/imgact_aout.c (revision 6af83ee0d2941d18880b6aaa2b4facd1d30c6106)
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 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/exec.h>
32 #include <sys/imgact.h>
33 #include <sys/imgact_aout.h>
34 #include <sys/kernel.h>
35 #include <sys/lock.h>
36 #include <sys/malloc.h>
37 #include <sys/mutex.h>
38 #include <sys/proc.h>
39 #include <sys/resourcevar.h>
40 #include <sys/signalvar.h>
41 #include <sys/syscall.h>
42 #include <sys/sysent.h>
43 #include <sys/systm.h>
44 #include <sys/vnode.h>
45 
46 #include <machine/frame.h>
47 #include <machine/md_var.h>
48 
49 #include <vm/vm.h>
50 #include <vm/pmap.h>
51 #include <vm/vm_map.h>
52 #include <vm/vm_object.h>
53 #include <vm/vm_param.h>
54 
55 static int	exec_aout_imgact(struct image_params *imgp);
56 static int	aout_fixup(register_t **stack_base, struct image_params *imgp);
57 
58 struct sysentvec aout_sysvec = {
59 	SYS_MAXSYSCALL,
60 	sysent,
61 	0,
62 	0,
63 	NULL,
64 	0,
65 	NULL,
66 	NULL,
67 	aout_fixup,
68 	sendsig,
69 	sigcode,
70 	&szsigcode,
71 	NULL,
72 	"FreeBSD a.out",
73 	NULL,
74 	NULL,
75 	MINSIGSTKSZ,
76 	PAGE_SIZE,
77 	VM_MIN_ADDRESS,
78 	VM_MAXUSER_ADDRESS,
79 	USRSTACK,
80 	PS_STRINGS,
81 	VM_PROT_ALL,
82 	exec_copyout_strings,
83 	exec_setregs,
84 	NULL
85 };
86 
87 static int
88 aout_fixup(stack_base, imgp)
89 	register_t **stack_base;
90 	struct image_params *imgp;
91 {
92 
93 	return (suword(--(*stack_base), imgp->args->argc));
94 }
95 
96 static int
97 exec_aout_imgact(imgp)
98 	struct image_params *imgp;
99 {
100 	const struct exec *a_out = (const struct exec *) imgp->image_header;
101 	struct vmspace *vmspace;
102 	struct vnode *vp;
103 	vm_map_t map;
104 	vm_object_t object;
105 	vm_offset_t text_end, data_end;
106 	unsigned long virtual_offset;
107 	unsigned long file_offset;
108 	unsigned long bss_size;
109 	int error;
110 
111 	GIANT_REQUIRED;
112 
113 	/*
114 	 * Linux and *BSD binaries look very much alike,
115 	 * only the machine id is different:
116 	 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
117 	 * NetBSD is in network byte order.. ugh.
118 	 */
119 	if (((a_out->a_magic >> 16) & 0xff) != 0x86 &&
120 	    ((a_out->a_magic >> 16) & 0xff) != 0 &&
121 	    ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86)
122                 return -1;
123 
124 	/*
125 	 * Set file/virtual offset based on a.out variant.
126 	 *	We do two cases: host byte order and network byte order
127 	 *	(for NetBSD compatibility)
128 	 */
129 	switch ((int)(a_out->a_magic & 0xffff)) {
130 	case ZMAGIC:
131 		virtual_offset = 0;
132 		if (a_out->a_text) {
133 			file_offset = PAGE_SIZE;
134 		} else {
135 			/* Bill's "screwball mode" */
136 			file_offset = 0;
137 		}
138 		break;
139 	case QMAGIC:
140 		virtual_offset = PAGE_SIZE;
141 		file_offset = 0;
142 		/* Pass PS_STRINGS for BSD/OS binaries only. */
143 		if (N_GETMID(*a_out) == MID_ZERO)
144 			imgp->ps_strings = aout_sysvec.sv_psstrings;
145 		break;
146 	default:
147 		/* NetBSD compatibility */
148 		switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
149 		case ZMAGIC:
150 		case QMAGIC:
151 			virtual_offset = PAGE_SIZE;
152 			file_offset = 0;
153 			break;
154 		default:
155 			return (-1);
156 		}
157 	}
158 
159 	bss_size = roundup(a_out->a_bss, PAGE_SIZE);
160 
161 	/*
162 	 * Check various fields in header for validity/bounds.
163 	 */
164 	if (/* entry point must lay with text region */
165 	    a_out->a_entry < virtual_offset ||
166 	    a_out->a_entry >= virtual_offset + a_out->a_text ||
167 
168 	    /* text and data size must each be page rounded */
169 	    a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK)
170 		return (-1);
171 
172 	/* text + data can't exceed file size */
173 	if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
174 		return (EFAULT);
175 
176 	/*
177 	 * text/data/bss must not exceed limits
178 	 */
179 	PROC_LOCK(imgp->proc);
180 	if (/* text can't exceed maximum text size */
181 	    a_out->a_text > maxtsiz ||
182 
183 	    /* data + bss can't exceed rlimit */
184 	    a_out->a_data + bss_size > lim_cur(imgp->proc, RLIMIT_DATA)) {
185 			PROC_UNLOCK(imgp->proc);
186 			return (ENOMEM);
187 	}
188 	PROC_UNLOCK(imgp->proc);
189 
190 	/*
191 	 * Destroy old process VM and create a new one (with a new stack)
192 	 */
193 	exec_new_vmspace(imgp, &aout_sysvec);
194 
195 	/*
196 	 * The vm space can be changed by exec_new_vmspace
197 	 */
198 	vmspace = imgp->proc->p_vmspace;
199 
200 	vp = imgp->vp;
201 	object = imgp->object;
202 	map = &vmspace->vm_map;
203 	vm_map_lock(map);
204 	vm_object_reference(object);
205 
206 	text_end = virtual_offset + a_out->a_text;
207 	error = vm_map_insert(map, object,
208 		file_offset,
209 		virtual_offset, text_end,
210 		VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
211 		MAP_COPY_ON_WRITE | MAP_PREFAULT);
212 	if (error) {
213 		vm_map_unlock(map);
214 		return (error);
215 	}
216 	data_end = text_end + a_out->a_data;
217 	if (a_out->a_data) {
218 		vm_object_reference(object);
219 		error = vm_map_insert(map, object,
220 			file_offset + a_out->a_text,
221 			text_end, data_end,
222 			VM_PROT_ALL, VM_PROT_ALL,
223 			MAP_COPY_ON_WRITE | MAP_PREFAULT);
224 		if (error) {
225 			vm_map_unlock(map);
226 			return (error);
227 		}
228 	}
229 
230 	if (bss_size) {
231 		error = vm_map_insert(map, NULL, 0,
232 			data_end, data_end + bss_size,
233 			VM_PROT_ALL, VM_PROT_ALL, 0);
234 		if (error) {
235 			vm_map_unlock(map);
236 			return (error);
237 		}
238 	}
239 	vm_map_unlock(map);
240 
241 	/* Fill in process VM information */
242 	vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
243 	vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
244 	vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset;
245 	vmspace->vm_daddr = (caddr_t) (uintptr_t)
246 			    (virtual_offset + a_out->a_text);
247 
248 	/* Fill in image_params */
249 	imgp->interpreted = 0;
250 	imgp->entry_addr = a_out->a_entry;
251 
252 	imgp->proc->p_sysent = &aout_sysvec;
253 
254 	return (0);
255 }
256 
257 /*
258  * Tell kern_execve.c about it, with a little help from the linker.
259  */
260 static struct execsw aout_execsw = { exec_aout_imgact, "a.out" };
261 EXEC_SET(aout, aout_execsw);
262