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: src/sys/kern/imgact_aout.c,v 1.104 2008/01/13 14:44:08 attilio Exp $");
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 vm_map_t map;
103 vm_object_t object;
104 vm_offset_t text_end, data_end;
105 unsigned long virtual_offset;
106 unsigned long file_offset;
107 unsigned long bss_size;
108 int error;
109
110 /*
111 * Linux and *BSD binaries look very much alike,
112 * only the machine id is different:
113 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
114 * NetBSD is in network byte order.. ugh.
115 */
116 if (((a_out->a_magic >> 16) & 0xff) != 0x86 &&
117 ((a_out->a_magic >> 16) & 0xff) != 0 &&
118 ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86)
119 return -1;
120
121 /*
122 * Set file/virtual offset based on a.out variant.
123 * We do two cases: host byte order and network byte order
124 * (for NetBSD compatibility)
125 */
126 switch ((int)(a_out->a_magic & 0xffff)) {
127 case ZMAGIC:
128 virtual_offset = 0;
129 if (a_out->a_text) {
130 file_offset = PAGE_SIZE;
131 } else {
132 /* Bill's "screwball mode" */
133 file_offset = 0;
134 }
135 break;
136 case QMAGIC:
137 virtual_offset = PAGE_SIZE;
138 file_offset = 0;
139 /* Pass PS_STRINGS for BSD/OS binaries only. */
140 if (N_GETMID(*a_out) == MID_ZERO)
141 imgp->ps_strings = aout_sysvec.sv_psstrings;
142 break;
143 default:
144 /* NetBSD compatibility */
145 switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
146 case ZMAGIC:
147 case QMAGIC:
148 virtual_offset = PAGE_SIZE;
149 file_offset = 0;
150 break;
151 default:
152 return (-1);
153 }
154 }
155
156 bss_size = roundup(a_out->a_bss, PAGE_SIZE);
157
158 /*
159 * Check various fields in header for validity/bounds.
160 */
161 if (/* entry point must lay with text region */
162 a_out->a_entry < virtual_offset ||
163 a_out->a_entry >= virtual_offset + a_out->a_text ||
164
165 /* text and data size must each be page rounded */
166 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK)
167 return (-1);
168
169 /* text + data can't exceed file size */
170 if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
171 return (EFAULT);
172
173 /*
174 * text/data/bss must not exceed limits
175 */
176 PROC_LOCK(imgp->proc);
177 if (/* text can't exceed maximum text size */
178 a_out->a_text > maxtsiz ||
179
180 /* data + bss can't exceed rlimit */
181 a_out->a_data + bss_size > lim_cur(imgp->proc, RLIMIT_DATA)) {
182 PROC_UNLOCK(imgp->proc);
183 return (ENOMEM);
184 }
185 PROC_UNLOCK(imgp->proc);
186
187 /*
188 * Avoid a possible deadlock if the current address space is destroyed
189 * and that address space maps the locked vnode. In the common case,
190 * the locked vnode's v_usecount is decremented but remains greater
191 * than zero. Consequently, the vnode lock is not needed by vrele().
192 * However, in cases where the vnode lock is external, such as nullfs,
193 * v_usecount may become zero.
194 */
195 VOP_UNLOCK(imgp->vp, 0);
196
197 /*
198 * Destroy old process VM and create a new one (with a new stack)
199 */
200 error = exec_new_vmspace(imgp, &aout_sysvec);
201
202 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
203 if (error)
204 return (error);
205
206 /*
207 * The vm space can be changed by exec_new_vmspace
208 */
209 vmspace = imgp->proc->p_vmspace;
210
211 object = imgp->object;
212 map = &vmspace->vm_map;
213 vm_map_lock(map);
214 vm_object_reference(object);
215
216 text_end = virtual_offset + a_out->a_text;
217 error = vm_map_insert(map, object,
218 file_offset,
219 virtual_offset, text_end,
220 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
221 MAP_COPY_ON_WRITE | MAP_PREFAULT);
222 if (error) {
223 vm_map_unlock(map);
224 vm_object_deallocate(object);
225 return (error);
226 }
227 data_end = text_end + a_out->a_data;
228 if (a_out->a_data) {
229 vm_object_reference(object);
230 error = vm_map_insert(map, object,
231 file_offset + a_out->a_text,
232 text_end, data_end,
233 VM_PROT_ALL, VM_PROT_ALL,
234 MAP_COPY_ON_WRITE | MAP_PREFAULT);
235 if (error) {
236 vm_map_unlock(map);
237 vm_object_deallocate(object);
238 return (error);
239 }
240 }
241
242 if (bss_size) {
243 error = vm_map_insert(map, NULL, 0,
244 data_end, data_end + bss_size,
245 VM_PROT_ALL, VM_PROT_ALL, 0);
246 if (error) {
247 vm_map_unlock(map);
248 return (error);
249 }
250 }
251 vm_map_unlock(map);
252
253 /* Fill in process VM information */
254 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
255 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
256 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset;
257 vmspace->vm_daddr = (caddr_t) (uintptr_t)
258 (virtual_offset + a_out->a_text);
259
260 /* Fill in image_params */
261 imgp->interpreted = 0;
262 imgp->entry_addr = a_out->a_entry;
263
264 imgp->proc->p_sysent = &aout_sysvec;
265
266 return (0);
267 }
268
269 /*
270 * Tell kern_execve.c about it, with a little help from the linker.
271 */
272 static struct execsw aout_execsw = { exec_aout_imgact, "a.out" };
273 EXEC_SET(aout, aout_execsw);
274
|