xref: /freebsd/sys/kern/imgact_aout.c (revision 6b3455a7665208c366849f0b2b3bc916fb97516e)
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 #include <sys/user.h>
46 
47 #include <machine/frame.h>
48 #include <machine/md_var.h>
49 
50 #include <vm/vm.h>
51 #include <vm/pmap.h>
52 #include <vm/vm_map.h>
53 #include <vm/vm_object.h>
54 #include <vm/vm_param.h>
55 
56 static int	exec_aout_imgact(struct image_params *imgp);
57 static int	aout_fixup(register_t **stack_base, struct image_params *imgp);
58 
59 struct sysentvec aout_sysvec = {
60 	SYS_MAXSYSCALL,
61 	sysent,
62 	0,
63 	0,
64 	NULL,
65 	0,
66 	NULL,
67 	NULL,
68 	aout_fixup,
69 	sendsig,
70 	sigcode,
71 	&szsigcode,
72 	NULL,
73 	"FreeBSD a.out",
74 	aout_coredump,
75 	NULL,
76 	MINSIGSTKSZ,
77 	PAGE_SIZE,
78 	VM_MIN_ADDRESS,
79 	VM_MAXUSER_ADDRESS,
80 	USRSTACK,
81 	PS_STRINGS,
82 	VM_PROT_ALL,
83 	exec_copyout_strings,
84 	exec_setregs,
85 	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->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 vmspace *vmspace;
103 	struct vnode *vp;
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 	GIANT_REQUIRED;
113 
114 	/*
115 	 * Linux and *BSD binaries look very much alike,
116 	 * only the machine id is different:
117 	 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
118 	 * NetBSD is in network byte order.. ugh.
119 	 */
120 	if (((a_out->a_magic >> 16) & 0xff) != 0x86 &&
121 	    ((a_out->a_magic >> 16) & 0xff) != 0 &&
122 	    ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86)
123                 return -1;
124 
125 	/*
126 	 * Set file/virtual offset based on a.out variant.
127 	 *	We do two cases: host byte order and network byte order
128 	 *	(for NetBSD compatibility)
129 	 */
130 	switch ((int)(a_out->a_magic & 0xffff)) {
131 	case ZMAGIC:
132 		virtual_offset = 0;
133 		if (a_out->a_text) {
134 			file_offset = PAGE_SIZE;
135 		} else {
136 			/* Bill's "screwball mode" */
137 			file_offset = 0;
138 		}
139 		break;
140 	case QMAGIC:
141 		virtual_offset = PAGE_SIZE;
142 		file_offset = 0;
143 		/* Pass PS_STRINGS for BSD/OS binaries only. */
144 		if (N_GETMID(*a_out) == MID_ZERO)
145 			imgp->ps_strings = aout_sysvec.sv_psstrings;
146 		break;
147 	default:
148 		/* NetBSD compatibility */
149 		switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
150 		case ZMAGIC:
151 		case QMAGIC:
152 			virtual_offset = PAGE_SIZE;
153 			file_offset = 0;
154 			break;
155 		default:
156 			return (-1);
157 		}
158 	}
159 
160 	bss_size = roundup(a_out->a_bss, PAGE_SIZE);
161 
162 	/*
163 	 * Check various fields in header for validity/bounds.
164 	 */
165 	if (/* entry point must lay with text region */
166 	    a_out->a_entry < virtual_offset ||
167 	    a_out->a_entry >= virtual_offset + a_out->a_text ||
168 
169 	    /* text and data size must each be page rounded */
170 	    a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK)
171 		return (-1);
172 
173 	/* text + data can't exceed file size */
174 	if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
175 		return (EFAULT);
176 
177 	/*
178 	 * text/data/bss must not exceed limits
179 	 */
180 	PROC_LOCK(imgp->proc);
181 	if (/* text can't exceed maximum text size */
182 	    a_out->a_text > maxtsiz ||
183 
184 	    /* data + bss can't exceed rlimit */
185 	    a_out->a_data + bss_size > lim_cur(imgp->proc, RLIMIT_DATA)) {
186 			PROC_UNLOCK(imgp->proc);
187 			return (ENOMEM);
188 	}
189 	PROC_UNLOCK(imgp->proc);
190 
191 	/* copy in arguments and/or environment from old process */
192 	error = exec_extract_strings(imgp);
193 	if (error)
194 		return (error);
195 
196 	/*
197 	 * Destroy old process VM and create a new one (with a new stack)
198 	 */
199 	exec_new_vmspace(imgp, &aout_sysvec);
200 
201 	/*
202 	 * The vm space can be changed by exec_new_vmspace
203 	 */
204 	vmspace = imgp->proc->p_vmspace;
205 
206 	vp = imgp->vp;
207 	object = imgp->object;
208 	map = &vmspace->vm_map;
209 	vm_map_lock(map);
210 	vm_object_reference(object);
211 
212 	text_end = virtual_offset + a_out->a_text;
213 	error = vm_map_insert(map, object,
214 		file_offset,
215 		virtual_offset, text_end,
216 		VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
217 		MAP_COPY_ON_WRITE | MAP_PREFAULT);
218 	if (error) {
219 		vm_map_unlock(map);
220 		return (error);
221 	}
222 	data_end = text_end + a_out->a_data;
223 	if (a_out->a_data) {
224 		vm_object_reference(object);
225 		error = vm_map_insert(map, object,
226 			file_offset + a_out->a_text,
227 			text_end, data_end,
228 			VM_PROT_ALL, VM_PROT_ALL,
229 			MAP_COPY_ON_WRITE | MAP_PREFAULT);
230 		if (error) {
231 			vm_map_unlock(map);
232 			return (error);
233 		}
234 	}
235 
236 	if (bss_size) {
237 		error = vm_map_insert(map, NULL, 0,
238 			data_end, data_end + bss_size,
239 			VM_PROT_ALL, VM_PROT_ALL, 0);
240 		if (error) {
241 			vm_map_unlock(map);
242 			return (error);
243 		}
244 	}
245 	vm_map_unlock(map);
246 
247 	/* Fill in process VM information */
248 	vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
249 	vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
250 	vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset;
251 	vmspace->vm_daddr = (caddr_t) (uintptr_t)
252 			    (virtual_offset + a_out->a_text);
253 
254 	/* Fill in image_params */
255 	imgp->interpreted = 0;
256 	imgp->entry_addr = a_out->a_entry;
257 
258 	imgp->proc->p_sysent = &aout_sysvec;
259 
260 	return (0);
261 }
262 
263 /*
264  * Dump core, into a file named as described in the comments for
265  * expand_name(), unless the process was setuid/setgid.
266  */
267 int
268 aout_coredump(td, vp, limit)
269 	register struct thread *td;
270 	register struct vnode *vp;
271 	off_t limit;
272 {
273 	struct proc *p = td->td_proc;
274 	register struct ucred *cred = td->td_ucred;
275 	register struct vmspace *vm = p->p_vmspace;
276 	char *tempuser;
277 	int error;
278 
279 	if (ctob((uarea_pages + kstack_pages)
280 	    + vm->vm_dsize + vm->vm_ssize) >= limit)
281 		return (EFAULT);
282 	tempuser = malloc(ctob(uarea_pages + kstack_pages), M_TEMP,
283 	    M_WAITOK | M_ZERO);
284 	if (tempuser == NULL)
285 		return (ENOMEM);
286 	PROC_LOCK(p);
287 	fill_kinfo_proc(p, &p->p_uarea->u_kproc);
288 	PROC_UNLOCK(p);
289 	bcopy(p->p_uarea, tempuser, sizeof(struct user));
290 	bcopy(td->td_frame,
291 	    tempuser + ctob(uarea_pages) +
292 	    ((caddr_t)td->td_frame - (caddr_t)td->td_kstack),
293 	    sizeof(struct trapframe));
294 	error = vn_rdwr(UIO_WRITE, vp, (caddr_t)tempuser,
295 	    ctob(uarea_pages + kstack_pages),
296 	    (off_t)0, UIO_SYSSPACE, IO_UNIT, cred, NOCRED,
297 	    (int *)NULL, td);
298 	free(tempuser, M_TEMP);
299 	if (error == 0)
300 		error = vn_rdwr(UIO_WRITE, vp, vm->vm_daddr,
301 		    (int)ctob(vm->vm_dsize),
302 		    (off_t)ctob(uarea_pages + kstack_pages), UIO_USERSPACE,
303 		    IO_UNIT | IO_DIRECT, cred, NOCRED, (int *) NULL, td);
304 	if (error == 0)
305 		error = vn_rdwr_inchunks(UIO_WRITE, vp,
306 		    (caddr_t)trunc_page(p->p_sysent->sv_usrstack -
307 		    ctob(vm->vm_ssize)), round_page(ctob(vm->vm_ssize)),
308 		    (off_t)ctob(uarea_pages + kstack_pages) +
309 		        ctob(vm->vm_dsize), UIO_USERSPACE,
310 		    IO_UNIT | IO_DIRECT, cred, NOCRED, NULL, td);
311 	return (error);
312 }
313 
314 /*
315  * Tell kern_execve.c about it, with a little help from the linker.
316  */
317 static struct execsw aout_execsw = { exec_aout_imgact, "a.out" };
318 EXEC_SET(aout, aout_execsw);
319