xref: /freebsd/sys/kern/imgact_aout.c (revision 7750ad47a9a7dbc83f87158464170c8640723293)
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/limits.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/mutex.h>
39 #include <sys/proc.h>
40 #include <sys/racct.h>
41 #include <sys/resourcevar.h>
42 #include <sys/signalvar.h>
43 #include <sys/syscall.h>
44 #include <sys/sysent.h>
45 #include <sys/systm.h>
46 #include <sys/vnode.h>
47 
48 #include <machine/frame.h>
49 #include <machine/md_var.h>
50 
51 #include <vm/vm.h>
52 #include <vm/pmap.h>
53 #include <vm/vm_map.h>
54 #include <vm/vm_object.h>
55 #include <vm/vm_param.h>
56 
57 #ifdef __amd64__
58 #include <compat/freebsd32/freebsd32_signal.h>
59 #include <compat/freebsd32/freebsd32_util.h>
60 #include <compat/freebsd32/freebsd32_proto.h>
61 #include <compat/freebsd32/freebsd32_syscall.h>
62 #include <compat/ia32/ia32_signal.h>
63 #endif
64 
65 static int	exec_aout_imgact(struct image_params *imgp);
66 static int	aout_fixup(register_t **stack_base, struct image_params *imgp);
67 
68 #if defined(__i386__)
69 struct sysentvec aout_sysvec = {
70 	.sv_size	= SYS_MAXSYSCALL,
71 	.sv_table	= sysent,
72 	.sv_mask	= 0,
73 	.sv_sigsize	= 0,
74 	.sv_sigtbl	= NULL,
75 	.sv_errsize	= 0,
76 	.sv_errtbl	= NULL,
77 	.sv_transtrap	= NULL,
78 	.sv_fixup	= aout_fixup,
79 	.sv_sendsig	= sendsig,
80 	.sv_sigcode	= sigcode,
81 	.sv_szsigcode	= &szsigcode,
82 	.sv_prepsyscall	= NULL,
83 	.sv_name	= "FreeBSD a.out",
84 	.sv_coredump	= NULL,
85 	.sv_imgact_try	= NULL,
86 	.sv_minsigstksz	= MINSIGSTKSZ,
87 	.sv_pagesize	= PAGE_SIZE,
88 	.sv_minuser	= VM_MIN_ADDRESS,
89 	.sv_maxuser	= VM_MAXUSER_ADDRESS,
90 	.sv_usrstack	= USRSTACK,
91 	.sv_psstrings	= PS_STRINGS,
92 	.sv_stackprot	= VM_PROT_ALL,
93 	.sv_copyout_strings	= exec_copyout_strings,
94 	.sv_setregs	= exec_setregs,
95 	.sv_fixlimit	= NULL,
96 	.sv_maxssiz	= NULL,
97 	.sv_flags	= SV_ABI_FREEBSD | SV_AOUT | SV_IA32 | SV_ILP32,
98 	.sv_set_syscall_retval = cpu_set_syscall_retval,
99 	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
100 	.sv_syscallnames = syscallnames,
101 	.sv_schedtail	= NULL,
102 };
103 
104 #elif defined(__amd64__)
105 
106 #define	AOUT32_USRSTACK	0xbfc00000
107 #define	AOUT32_PS_STRINGS \
108     (AOUT32_USRSTACK - sizeof(struct freebsd32_ps_strings))
109 
110 extern const char *freebsd32_syscallnames[];
111 extern u_long ia32_maxssiz;
112 
113 struct sysentvec aout_sysvec = {
114 	.sv_size	= FREEBSD32_SYS_MAXSYSCALL,
115 	.sv_table	= freebsd32_sysent,
116 	.sv_mask	= 0,
117 	.sv_sigsize	= 0,
118 	.sv_sigtbl	= NULL,
119 	.sv_errsize	= 0,
120 	.sv_errtbl	= NULL,
121 	.sv_transtrap	= NULL,
122 	.sv_fixup	= aout_fixup,
123 	.sv_sendsig	= ia32_sendsig,
124 	.sv_sigcode	= ia32_sigcode,
125 	.sv_szsigcode	= &sz_ia32_sigcode,
126 	.sv_prepsyscall	= NULL,
127 	.sv_name	= "FreeBSD a.out",
128 	.sv_coredump	= NULL,
129 	.sv_imgact_try	= NULL,
130 	.sv_minsigstksz	= MINSIGSTKSZ,
131 	.sv_pagesize	= IA32_PAGE_SIZE,
132 	.sv_minuser	= 0,
133 	.sv_maxuser	= AOUT32_USRSTACK,
134 	.sv_usrstack	= AOUT32_USRSTACK,
135 	.sv_psstrings	= AOUT32_PS_STRINGS,
136 	.sv_stackprot	= VM_PROT_ALL,
137 	.sv_copyout_strings	= freebsd32_copyout_strings,
138 	.sv_setregs	= ia32_setregs,
139 	.sv_fixlimit	= ia32_fixlimit,
140 	.sv_maxssiz	= &ia32_maxssiz,
141 	.sv_flags	= SV_ABI_FREEBSD | SV_AOUT | SV_IA32 | SV_ILP32,
142 	.sv_set_syscall_retval = ia32_set_syscall_retval,
143 	.sv_fetch_syscall_args = ia32_fetch_syscall_args,
144 	.sv_syscallnames = freebsd32_syscallnames,
145 };
146 #else
147 #error "Port me"
148 #endif
149 
150 static int
151 aout_fixup(register_t **stack_base, struct image_params *imgp)
152 {
153 
154 	*(char **)stack_base -= sizeof(uint32_t);
155 	return (suword32(*stack_base, imgp->args->argc));
156 }
157 
158 static int
159 exec_aout_imgact(struct image_params *imgp)
160 {
161 	const struct exec *a_out = (const struct exec *) imgp->image_header;
162 	struct vmspace *vmspace;
163 	vm_map_t map;
164 	vm_object_t object;
165 	vm_offset_t text_end, data_end;
166 	unsigned long virtual_offset;
167 	unsigned long file_offset;
168 	unsigned long bss_size;
169 	int error;
170 
171 	/*
172 	 * Linux and *BSD binaries look very much alike,
173 	 * only the machine id is different:
174 	 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
175 	 * NetBSD is in network byte order.. ugh.
176 	 */
177 	if (((a_out->a_magic >> 16) & 0xff) != 0x86 &&
178 	    ((a_out->a_magic >> 16) & 0xff) != 0 &&
179 	    ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86)
180                 return -1;
181 
182 	/*
183 	 * Set file/virtual offset based on a.out variant.
184 	 *	We do two cases: host byte order and network byte order
185 	 *	(for NetBSD compatibility)
186 	 */
187 	switch ((int)(a_out->a_magic & 0xffff)) {
188 	case ZMAGIC:
189 		virtual_offset = 0;
190 		if (a_out->a_text) {
191 			file_offset = PAGE_SIZE;
192 		} else {
193 			/* Bill's "screwball mode" */
194 			file_offset = 0;
195 		}
196 		break;
197 	case QMAGIC:
198 		virtual_offset = PAGE_SIZE;
199 		file_offset = 0;
200 		/* Pass PS_STRINGS for BSD/OS binaries only. */
201 		if (N_GETMID(*a_out) == MID_ZERO)
202 			imgp->ps_strings = aout_sysvec.sv_psstrings;
203 		break;
204 	default:
205 		/* NetBSD compatibility */
206 		switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
207 		case ZMAGIC:
208 		case QMAGIC:
209 			virtual_offset = PAGE_SIZE;
210 			file_offset = 0;
211 			break;
212 		default:
213 			return (-1);
214 		}
215 	}
216 
217 	bss_size = roundup(a_out->a_bss, PAGE_SIZE);
218 
219 	/*
220 	 * Check various fields in header for validity/bounds.
221 	 */
222 	if (/* entry point must lay with text region */
223 	    a_out->a_entry < virtual_offset ||
224 	    a_out->a_entry >= virtual_offset + a_out->a_text ||
225 
226 	    /* text and data size must each be page rounded */
227 	    a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK
228 
229 #ifdef __amd64__
230 	    ||
231 	    /* overflows */
232 	    virtual_offset + a_out->a_text + a_out->a_data + bss_size > UINT_MAX
233 #endif
234 	    )
235 		return (-1);
236 
237 	/* text + data can't exceed file size */
238 	if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
239 		return (EFAULT);
240 
241 	/*
242 	 * text/data/bss must not exceed limits
243 	 */
244 	PROC_LOCK(imgp->proc);
245 	if (/* text can't exceed maximum text size */
246 	    a_out->a_text > maxtsiz ||
247 
248 	    /* data + bss can't exceed rlimit */
249 	    a_out->a_data + bss_size > lim_cur(imgp->proc, RLIMIT_DATA) ||
250 	    racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) {
251 			PROC_UNLOCK(imgp->proc);
252 			return (ENOMEM);
253 	}
254 	PROC_UNLOCK(imgp->proc);
255 
256 	/*
257 	 * Avoid a possible deadlock if the current address space is destroyed
258 	 * and that address space maps the locked vnode.  In the common case,
259 	 * the locked vnode's v_usecount is decremented but remains greater
260 	 * than zero.  Consequently, the vnode lock is not needed by vrele().
261 	 * However, in cases where the vnode lock is external, such as nullfs,
262 	 * v_usecount may become zero.
263 	 */
264 	VOP_UNLOCK(imgp->vp, 0);
265 
266 	/*
267 	 * Destroy old process VM and create a new one (with a new stack)
268 	 */
269 	error = exec_new_vmspace(imgp, &aout_sysvec);
270 
271 	vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
272 	if (error)
273 		return (error);
274 
275 	/*
276 	 * The vm space can be changed by exec_new_vmspace
277 	 */
278 	vmspace = imgp->proc->p_vmspace;
279 
280 	object = imgp->object;
281 	map = &vmspace->vm_map;
282 	vm_map_lock(map);
283 	vm_object_reference(object);
284 
285 	text_end = virtual_offset + a_out->a_text;
286 	error = vm_map_insert(map, object,
287 		file_offset,
288 		virtual_offset, text_end,
289 		VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
290 		MAP_COPY_ON_WRITE | MAP_PREFAULT);
291 	if (error) {
292 		vm_map_unlock(map);
293 		vm_object_deallocate(object);
294 		return (error);
295 	}
296 	data_end = text_end + a_out->a_data;
297 	if (a_out->a_data) {
298 		vm_object_reference(object);
299 		error = vm_map_insert(map, object,
300 			file_offset + a_out->a_text,
301 			text_end, data_end,
302 			VM_PROT_ALL, VM_PROT_ALL,
303 			MAP_COPY_ON_WRITE | MAP_PREFAULT);
304 		if (error) {
305 			vm_map_unlock(map);
306 			vm_object_deallocate(object);
307 			return (error);
308 		}
309 	}
310 
311 	if (bss_size) {
312 		error = vm_map_insert(map, NULL, 0,
313 			data_end, data_end + bss_size,
314 			VM_PROT_ALL, VM_PROT_ALL, 0);
315 		if (error) {
316 			vm_map_unlock(map);
317 			return (error);
318 		}
319 	}
320 	vm_map_unlock(map);
321 
322 	/* Fill in process VM information */
323 	vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
324 	vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
325 	vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset;
326 	vmspace->vm_daddr = (caddr_t) (uintptr_t)
327 			    (virtual_offset + a_out->a_text);
328 
329 	/* Fill in image_params */
330 	imgp->interpreted = 0;
331 	imgp->entry_addr = a_out->a_entry;
332 
333 	imgp->proc->p_sysent = &aout_sysvec;
334 
335 	return (0);
336 }
337 
338 /*
339  * Tell kern_execve.c about it, with a little help from the linker.
340  */
341 static struct execsw aout_execsw = { exec_aout_imgact, "a.out" };
342 EXEC_SET(aout, aout_execsw);
343