xref: /freebsd/sys/kern/imgact_aout.c (revision 7660b554bc59a07be0431c17e0e33815818baa69)
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 };
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->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 	struct vnode *vp;
103 	vm_map_t map;
104 	vm_object_t object;
105 	vm_offset_t text_end, data_end;
106 	unsigned long virtual_offset;
107 	unsigned long file_offset;
108 	unsigned long bss_size;
109 	int error;
110 
111 	GIANT_REQUIRED;
112 
113 	/*
114 	 * Linux and *BSD binaries look very much alike,
115 	 * only the machine id is different:
116 	 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
117 	 * NetBSD is in network byte order.. ugh.
118 	 */
119 	if (((a_out->a_magic >> 16) & 0xff) != 0x86 &&
120 	    ((a_out->a_magic >> 16) & 0xff) != 0 &&
121 	    ((((int)ntohl(a_out->a_magic)) >> 16) & 0xff) != 0x86)
122                 return -1;
123 
124 	/*
125 	 * Set file/virtual offset based on a.out variant.
126 	 *	We do two cases: host byte order and network byte order
127 	 *	(for NetBSD compatibility)
128 	 */
129 	switch ((int)(a_out->a_magic & 0xffff)) {
130 	case ZMAGIC:
131 		virtual_offset = 0;
132 		if (a_out->a_text) {
133 			file_offset = PAGE_SIZE;
134 		} else {
135 			/* Bill's "screwball mode" */
136 			file_offset = 0;
137 		}
138 		break;
139 	case QMAGIC:
140 		virtual_offset = PAGE_SIZE;
141 		file_offset = 0;
142 		/* Pass PS_STRINGS for BSD/OS binaries only. */
143 		if (N_GETMID(*a_out) == MID_ZERO)
144 			imgp->ps_strings = aout_sysvec.sv_psstrings;
145 		break;
146 	default:
147 		/* NetBSD compatibility */
148 		switch ((int)(ntohl(a_out->a_magic) & 0xffff)) {
149 		case ZMAGIC:
150 		case QMAGIC:
151 			virtual_offset = PAGE_SIZE;
152 			file_offset = 0;
153 			break;
154 		default:
155 			return (-1);
156 		}
157 	}
158 
159 	bss_size = roundup(a_out->a_bss, PAGE_SIZE);
160 
161 	/*
162 	 * Check various fields in header for validity/bounds.
163 	 */
164 	if (/* entry point must lay with text region */
165 	    a_out->a_entry < virtual_offset ||
166 	    a_out->a_entry >= virtual_offset + a_out->a_text ||
167 
168 	    /* text and data size must each be page rounded */
169 	    a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK)
170 		return (-1);
171 
172 	/* text + data can't exceed file size */
173 	if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
174 		return (EFAULT);
175 
176 	/*
177 	 * text/data/bss must not exceed limits
178 	 */
179 	mtx_assert(&Giant, MA_OWNED);
180 	if (/* text can't exceed maximum text size */
181 	    a_out->a_text > maxtsiz ||
182 
183 	    /* data + bss can't exceed rlimit */
184 	    a_out->a_data + bss_size >
185 		imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur)
186 			return (ENOMEM);
187 
188 	/* copy in arguments and/or environment from old process */
189 	error = exec_extract_strings(imgp);
190 	if (error)
191 		return (error);
192 
193 	/*
194 	 * Destroy old process VM and create a new one (with a new stack)
195 	 */
196 	exec_new_vmspace(imgp, &aout_sysvec);
197 
198 	/*
199 	 * The vm space can be changed by exec_new_vmspace
200 	 */
201 	vmspace = imgp->proc->p_vmspace;
202 
203 	vp = imgp->vp;
204 	object = imgp->object;
205 	map = &vmspace->vm_map;
206 	vm_map_lock(map);
207 	vm_object_reference(object);
208 
209 	text_end = virtual_offset + a_out->a_text;
210 	error = vm_map_insert(map, object,
211 		file_offset,
212 		virtual_offset, text_end,
213 		VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
214 		MAP_COPY_ON_WRITE | MAP_PREFAULT);
215 	if (error) {
216 		vm_map_unlock(map);
217 		return (error);
218 	}
219 	data_end = text_end + a_out->a_data;
220 	if (a_out->a_data) {
221 		vm_object_reference(object);
222 		error = vm_map_insert(map, object,
223 			file_offset + a_out->a_text,
224 			text_end, data_end,
225 			VM_PROT_ALL, VM_PROT_ALL,
226 			MAP_COPY_ON_WRITE | MAP_PREFAULT);
227 		if (error) {
228 			vm_map_unlock(map);
229 			return (error);
230 		}
231 	}
232 
233 	if (bss_size) {
234 		error = vm_map_insert(map, NULL, 0,
235 			data_end, data_end + bss_size,
236 			VM_PROT_ALL, VM_PROT_ALL, 0);
237 		if (error) {
238 			vm_map_unlock(map);
239 			return (error);
240 		}
241 	}
242 	vm_map_unlock(map);
243 
244 	/* Fill in process VM information */
245 	vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
246 	vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
247 	vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset;
248 	vmspace->vm_daddr = (caddr_t) (uintptr_t)
249 			    (virtual_offset + a_out->a_text);
250 
251 	/* Fill in image_params */
252 	imgp->interpreted = 0;
253 	imgp->entry_addr = a_out->a_entry;
254 
255 	imgp->proc->p_sysent = &aout_sysvec;
256 
257 	return (0);
258 }
259 
260 /*
261  * Dump core, into a file named as described in the comments for
262  * expand_name(), unless the process was setuid/setgid.
263  */
264 int
265 aout_coredump(td, vp, limit)
266 	register struct thread *td;
267 	register struct vnode *vp;
268 	off_t limit;
269 {
270 	struct proc *p = td->td_proc;
271 	register struct ucred *cred = td->td_ucred;
272 	register struct vmspace *vm = p->p_vmspace;
273 	char *tempuser;
274 	int error;
275 
276 	if (ctob((uarea_pages + kstack_pages)
277 	    + vm->vm_dsize + vm->vm_ssize) >= limit)
278 		return (EFAULT);
279 	tempuser = malloc(ctob(uarea_pages + kstack_pages), M_TEMP,
280 	    M_WAITOK | M_ZERO);
281 	if (tempuser == NULL)
282 		return (ENOMEM);
283 	PROC_LOCK(p);
284 	fill_kinfo_proc(p, &p->p_uarea->u_kproc);
285 	PROC_UNLOCK(p);
286 	bcopy(p->p_uarea, tempuser, sizeof(struct user));
287 	bcopy(td->td_frame,
288 	    tempuser + ctob(uarea_pages) +
289 	    ((caddr_t)td->td_frame - (caddr_t)td->td_kstack),
290 	    sizeof(struct trapframe));
291 	error = vn_rdwr(UIO_WRITE, vp, (caddr_t)tempuser,
292 	    ctob(uarea_pages + kstack_pages),
293 	    (off_t)0, UIO_SYSSPACE, IO_UNIT, cred, NOCRED,
294 	    (int *)NULL, td);
295 	free(tempuser, M_TEMP);
296 	if (error == 0)
297 		error = vn_rdwr(UIO_WRITE, vp, vm->vm_daddr,
298 		    (int)ctob(vm->vm_dsize),
299 		    (off_t)ctob(uarea_pages + kstack_pages), UIO_USERSPACE,
300 		    IO_UNIT | IO_DIRECT, cred, NOCRED, (int *) NULL, td);
301 	if (error == 0)
302 		error = vn_rdwr_inchunks(UIO_WRITE, vp,
303 		    (caddr_t)trunc_page(p->p_sysent->sv_usrstack -
304 		    ctob(vm->vm_ssize)), round_page(ctob(vm->vm_ssize)),
305 		    (off_t)ctob(uarea_pages + kstack_pages) +
306 		        ctob(vm->vm_dsize), UIO_USERSPACE,
307 		    IO_UNIT | IO_DIRECT, cred, NOCRED, (int *) NULL, td);
308 	return (error);
309 }
310 
311 /*
312  * Tell kern_execve.c about it, with a little help from the linker.
313  */
314 static struct execsw aout_execsw = { exec_aout_imgact, "a.out" };
315 EXEC_SET(aout, aout_execsw);
316