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/8.2/sys/kern/imgact_aout.c 214755 2010-11-03 21:21:12Z 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 .sv_flags = SV_ABI_FREEBSD | SV_AOUT |
87 #if defined(__i386__)
88 SV_IA32 | SV_ILP32
89 #else
90 #error Choose SV_XXX flags for the platform
91 #endif
92 ,
93 .sv_set_syscall_retval = cpu_set_syscall_retval,
94 .sv_fetch_syscall_args = cpu_fetch_syscall_args,
95 .sv_syscallnames = syscallnames,
96 };
97
98 static int
99 aout_fixup(stack_base, imgp)
100 register_t **stack_base;
101 struct image_params *imgp;
102 {
103
104 return (suword(--(*stack_base), imgp->args->argc));
105 }
106
107 static int
108 exec_aout_imgact(imgp)
109 struct image_params *imgp;
110 {
111 const struct exec *a_out = (const struct exec *) imgp->image_header;
112 struct vmspace *vmspace;
113 vm_map_t map;
114 vm_object_t object;
115 vm_offset_t text_end, data_end;
116 unsigned long virtual_offset;
117 unsigned long file_offset;
118 unsigned long bss_size;
119 int error;
120
121 /*
122 * Linux and *BSD binaries look very much alike,
123 * only the machine id is different:
124 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
125 * NetBSD is in network byte order.. ugh.
126 */
127 if (((a_out->a_magic >> 16) & 0xff) != 0x86 &&
128 ((a_out->a_magic >> 16) & 0xff) != 0 &&
129 ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86)
130 return -1;
131
132 /*
133 * Set file/virtual offset based on a.out variant.
134 * We do two cases: host byte order and network byte order
135 * (for NetBSD compatibility)
136 */
137 switch ((int)(a_out->a_magic & 0xffff)) {
138 case ZMAGIC:
139 virtual_offset = 0;
140 if (a_out->a_text) {
141 file_offset = PAGE_SIZE;
142 } else {
143 /* Bill's "screwball mode" */
144 file_offset = 0;
145 }
146 break;
147 case QMAGIC:
148 virtual_offset = PAGE_SIZE;
149 file_offset = 0;
150 /* Pass PS_STRINGS for BSD/OS binaries only. */
151 if (N_GETMID(*a_out) == MID_ZERO)
152 imgp->ps_strings = aout_sysvec.sv_psstrings;
153 break;
154 default:
155 /* NetBSD compatibility */
156 switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
157 case ZMAGIC:
158 case QMAGIC:
159 virtual_offset = PAGE_SIZE;
160 file_offset = 0;
161 break;
162 default:
163 return (-1);
164 }
165 }
166
167 bss_size = roundup(a_out->a_bss, PAGE_SIZE);
168
169 /*
170 * Check various fields in header for validity/bounds.
171 */
172 if (/* entry point must lay with text region */
173 a_out->a_entry < virtual_offset ||
174 a_out->a_entry >= virtual_offset + a_out->a_text ||
175
176 /* text and data size must each be page rounded */
177 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK)
178 return (-1);
179
180 /* text + data can't exceed file size */
181 if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
182 return (EFAULT);
183
184 /*
185 * text/data/bss must not exceed limits
186 */
187 PROC_LOCK(imgp->proc);
188 if (/* text can't exceed maximum text size */
189 a_out->a_text > maxtsiz ||
190
191 /* data + bss can't exceed rlimit */
192 a_out->a_data + bss_size > lim_cur(imgp->proc, RLIMIT_DATA)) {
193 PROC_UNLOCK(imgp->proc);
194 return (ENOMEM);
195 }
196 PROC_UNLOCK(imgp->proc);
197
198 /*
199 * Avoid a possible deadlock if the current address space is destroyed
200 * and that address space maps the locked vnode. In the common case,
201 * the locked vnode's v_usecount is decremented but remains greater
202 * than zero. Consequently, the vnode lock is not needed by vrele().
203 * However, in cases where the vnode lock is external, such as nullfs,
204 * v_usecount may become zero.
205 */
206 VOP_UNLOCK(imgp->vp, 0);
207
208 /*
209 * Destroy old process VM and create a new one (with a new stack)
210 */
211 error = exec_new_vmspace(imgp, &aout_sysvec);
212
213 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
214 if (error)
215 return (error);
216
217 /*
218 * The vm space can be changed by exec_new_vmspace
219 */
220 vmspace = imgp->proc->p_vmspace;
221
222 object = imgp->object;
223 map = &vmspace->vm_map;
224 vm_map_lock(map);
225 vm_object_reference(object);
226
227 text_end = virtual_offset + a_out->a_text;
228 error = vm_map_insert(map, object,
229 file_offset,
230 virtual_offset, text_end,
231 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
232 MAP_COPY_ON_WRITE | MAP_PREFAULT);
233 if (error) {
234 vm_map_unlock(map);
235 vm_object_deallocate(object);
236 return (error);
237 }
238 data_end = text_end + a_out->a_data;
239 if (a_out->a_data) {
240 vm_object_reference(object);
241 error = vm_map_insert(map, object,
242 file_offset + a_out->a_text,
243 text_end, data_end,
244 VM_PROT_ALL, VM_PROT_ALL,
245 MAP_COPY_ON_WRITE | MAP_PREFAULT);
246 if (error) {
247 vm_map_unlock(map);
248 vm_object_deallocate(object);
249 return (error);
250 }
251 }
252
253 if (bss_size) {
254 error = vm_map_insert(map, NULL, 0,
255 data_end, data_end + bss_size,
256 VM_PROT_ALL, VM_PROT_ALL, 0);
257 if (error) {
258 vm_map_unlock(map);
259 return (error);
260 }
261 }
262 vm_map_unlock(map);
263
264 /* Fill in process VM information */
265 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
266 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
267 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset;
268 vmspace->vm_daddr = (caddr_t) (uintptr_t)
269 (virtual_offset + a_out->a_text);
270
271 /* Fill in image_params */
272 imgp->interpreted = 0;
273 imgp->entry_addr = a_out->a_entry;
274
275 imgp->proc->p_sysent = &aout_sysvec;
276
277 return (0);
278 }
279
280 /*
281 * Tell kern_execve.c about it, with a little help from the linker.
282 */
283 static struct execsw aout_execsw = { exec_aout_imgact, "a.out" };
284 EXEC_SET(aout, aout_execsw);
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