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: releng/7.3/sys/kern/imgact_aout.c 186936 2009-01-09 11:09:57Z kib $");
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 .sv_size = SYS_MAXSYSCALL,
60 .sv_table = sysent,
61 .sv_mask = 0,
62 .sv_sigsize = 0,
63 .sv_sigtbl = NULL,
64 .sv_errsize = 0,
65 .sv_errtbl = NULL,
66 .sv_transtrap = NULL,
67 .sv_fixup = aout_fixup,
68 .sv_sendsig = sendsig,
69 .sv_sigcode = sigcode,
70 .sv_szsigcode = &szsigcode,
71 .sv_prepsyscall = NULL,
72 .sv_name = "FreeBSD a.out",
73 .sv_coredump = NULL,
74 .sv_imgact_try = NULL,
75 .sv_minsigstksz = MINSIGSTKSZ,
76 .sv_pagesize = PAGE_SIZE,
77 .sv_minuser = VM_MIN_ADDRESS,
78 .sv_maxuser = VM_MAXUSER_ADDRESS,
79 .sv_usrstack = USRSTACK,
80 .sv_psstrings = PS_STRINGS,
81 .sv_stackprot = VM_PROT_ALL,
82 .sv_copyout_strings = exec_copyout_strings,
83 .sv_setregs = exec_setregs,
84 .sv_fixlimit = NULL,
85 .sv_maxssiz = NULL
86 };
87
88 static int
89 aout_fixup(stack_base, imgp)
90 register_t **stack_base;
91 struct image_params *imgp;
92 {
93
94 return (suword(--(*stack_base), imgp->args->argc));
95 }
96
97 static int
98 exec_aout_imgact(imgp)
99 struct image_params *imgp;
100 {
101 const struct exec *a_out = (const struct exec *) imgp->image_header;
102 struct thread *td = curthread;
103 struct vmspace *vmspace;
104 vm_map_t map;
105 vm_object_t object;
106 vm_offset_t text_end, data_end;
107 unsigned long virtual_offset;
108 unsigned long file_offset;
109 unsigned long bss_size;
110 int error;
111
112 /*
113 * Linux and *BSD binaries look very much alike,
114 * only the machine id is different:
115 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
116 * NetBSD is in network byte order.. ugh.
117 */
118 if (((a_out->a_magic >> 16) & 0xff) != 0x86 &&
119 ((a_out->a_magic >> 16) & 0xff) != 0 &&
120 ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86)
121 return -1;
122
123 /*
124 * Set file/virtual offset based on a.out variant.
125 * We do two cases: host byte order and network byte order
126 * (for NetBSD compatibility)
127 */
128 switch ((int)(a_out->a_magic & 0xffff)) {
129 case ZMAGIC:
130 virtual_offset = 0;
131 if (a_out->a_text) {
132 file_offset = PAGE_SIZE;
133 } else {
134 /* Bill's "screwball mode" */
135 file_offset = 0;
136 }
137 break;
138 case QMAGIC:
139 virtual_offset = PAGE_SIZE;
140 file_offset = 0;
141 /* Pass PS_STRINGS for BSD/OS binaries only. */
142 if (N_GETMID(*a_out) == MID_ZERO)
143 imgp->ps_strings = aout_sysvec.sv_psstrings;
144 break;
145 default:
146 /* NetBSD compatibility */
147 switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
148 case ZMAGIC:
149 case QMAGIC:
150 virtual_offset = PAGE_SIZE;
151 file_offset = 0;
152 break;
153 default:
154 return (-1);
155 }
156 }
157
158 bss_size = roundup(a_out->a_bss, PAGE_SIZE);
159
160 /*
161 * Check various fields in header for validity/bounds.
162 */
163 if (/* entry point must lay with text region */
164 a_out->a_entry < virtual_offset ||
165 a_out->a_entry >= virtual_offset + a_out->a_text ||
166
167 /* text and data size must each be page rounded */
168 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK)
169 return (-1);
170
171 /* text + data can't exceed file size */
172 if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
173 return (EFAULT);
174
175 /*
176 * text/data/bss must not exceed limits
177 */
178 PROC_LOCK(imgp->proc);
179 if (/* text can't exceed maximum text size */
180 a_out->a_text > maxtsiz ||
181
182 /* data + bss can't exceed rlimit */
183 a_out->a_data + bss_size > lim_cur(imgp->proc, RLIMIT_DATA)) {
184 PROC_UNLOCK(imgp->proc);
185 return (ENOMEM);
186 }
187 PROC_UNLOCK(imgp->proc);
188
189 /*
190 * Avoid a possible deadlock if the current address space is destroyed
191 * and that address space maps the locked vnode. In the common case,
192 * the locked vnode's v_usecount is decremented but remains greater
193 * than zero. Consequently, the vnode lock is not needed by vrele().
194 * However, in cases where the vnode lock is external, such as nullfs,
195 * v_usecount may become zero.
196 */
197 VOP_UNLOCK(imgp->vp, 0, td);
198
199 /*
200 * Destroy old process VM and create a new one (with a new stack)
201 */
202 error = exec_new_vmspace(imgp, &aout_sysvec);
203
204 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY, td);
205 if (error)
206 return (error);
207
208 /*
209 * The vm space can be changed by exec_new_vmspace
210 */
211 vmspace = imgp->proc->p_vmspace;
212
213 object = imgp->object;
214 map = &vmspace->vm_map;
215 vm_map_lock(map);
216 vm_object_reference(object);
217
218 text_end = virtual_offset + a_out->a_text;
219 error = vm_map_insert(map, object,
220 file_offset,
221 virtual_offset, text_end,
222 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
223 MAP_COPY_ON_WRITE | MAP_PREFAULT);
224 if (error) {
225 vm_map_unlock(map);
226 vm_object_deallocate(object);
227 return (error);
228 }
229 data_end = text_end + a_out->a_data;
230 if (a_out->a_data) {
231 vm_object_reference(object);
232 error = vm_map_insert(map, object,
233 file_offset + a_out->a_text,
234 text_end, data_end,
235 VM_PROT_ALL, VM_PROT_ALL,
236 MAP_COPY_ON_WRITE | MAP_PREFAULT);
237 if (error) {
238 vm_map_unlock(map);
239 vm_object_deallocate(object);
240 return (error);
241 }
242 }
243
244 if (bss_size) {
245 error = vm_map_insert(map, NULL, 0,
246 data_end, data_end + bss_size,
247 VM_PROT_ALL, VM_PROT_ALL, 0);
248 if (error) {
249 vm_map_unlock(map);
250 return (error);
251 }
252 }
253 vm_map_unlock(map);
254
255 /* Fill in process VM information */
256 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
257 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
258 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset;
259 vmspace->vm_daddr = (caddr_t) (uintptr_t)
260 (virtual_offset + a_out->a_text);
261
262 /* Fill in image_params */
263 imgp->interpreted = 0;
264 imgp->entry_addr = a_out->a_entry;
265
266 imgp->proc->p_sysent = &aout_sysvec;
267
268 return (0);
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);
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