1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 1993, David Greenman
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/param.h>
30 #include <sys/exec.h>
31 #include <sys/imgact.h>
32 #include <sys/imgact_aout.h>
33 #include <sys/kernel.h>
34 #include <sys/limits.h>
35 #include <sys/lock.h>
36 #include <sys/malloc.h>
37 #include <sys/mutex.h>
38 #include <sys/proc.h>
39 #include <sys/racct.h>
40 #include <sys/resourcevar.h>
41 #include <sys/signalvar.h>
42 #include <sys/syscall.h>
43 #include <sys/sysent.h>
44 #include <sys/systm.h>
45 #include <sys/vnode.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 #ifdef __amd64__
57 #include <compat/freebsd32/freebsd32_signal.h>
58 #include <compat/freebsd32/freebsd32_util.h>
59 #include <compat/freebsd32/freebsd32_proto.h>
60 #include <compat/freebsd32/freebsd32_syscall.h>
61 #include <compat/ia32/ia32_signal.h>
62 #endif
63
64 static int exec_aout_imgact(struct image_params *imgp);
65 static int aout_fixup(uintptr_t *stack_base, struct image_params *imgp);
66
67 #define AOUT32_USRSTACK 0xbfc00000
68
69 #if defined(__i386__)
70
71 #define AOUT32_PS_STRINGS (AOUT32_USRSTACK - sizeof(struct ps_strings))
72
73 struct sysentvec aout_sysvec = {
74 .sv_size = SYS_MAXSYSCALL,
75 .sv_table = sysent,
76 .sv_fixup = aout_fixup,
77 .sv_sendsig = sendsig,
78 .sv_sigcode = sigcode,
79 .sv_szsigcode = &szsigcode,
80 .sv_name = "FreeBSD a.out",
81 .sv_coredump = NULL,
82 .sv_minsigstksz = MINSIGSTKSZ,
83 .sv_minuser = VM_MIN_ADDRESS,
84 .sv_maxuser = AOUT32_USRSTACK,
85 .sv_usrstack = AOUT32_USRSTACK,
86 .sv_psstrings = AOUT32_PS_STRINGS,
87 .sv_psstringssz = sizeof(struct ps_strings),
88 .sv_stackprot = VM_PROT_ALL,
89 .sv_copyout_strings = exec_copyout_strings,
90 .sv_setregs = exec_setregs,
91 .sv_fixlimit = NULL,
92 .sv_maxssiz = NULL,
93 .sv_flags = SV_ABI_FREEBSD | SV_AOUT | SV_ILP32 | SV_SIGSYS,
94 .sv_set_syscall_retval = cpu_set_syscall_retval,
95 .sv_fetch_syscall_args = cpu_fetch_syscall_args,
96 .sv_syscallnames = syscallnames,
97 .sv_schedtail = NULL,
98 .sv_thread_detach = NULL,
99 .sv_trap = NULL,
100 .sv_onexec_old = exec_onexec_old,
101 .sv_onexit = exit_onexit,
102 .sv_set_fork_retval = x86_set_fork_retval,
103 };
104
105 #elif defined(__amd64__)
106
107 #include "vdso_ia32_offsets.h"
108
109 extern const char _binary_elf_vdso32_so_1_start[];
110 extern const char _binary_elf_vdso32_so_1_end[];
111 extern char _binary_elf_vdso32_so_1_size;
112
113 #define AOUT32_PS_STRINGS \
114 (AOUT32_USRSTACK - sizeof(struct freebsd32_ps_strings))
115 #define AOUT32_MINUSER FREEBSD32_MINUSER
116
117 extern const char *freebsd32_syscallnames[];
118 extern u_long ia32_maxssiz;
119
120 static int aout_szsigcode;
121
122 struct sysentvec aout_sysvec = {
123 .sv_size = FREEBSD32_SYS_MAXSYSCALL,
124 .sv_table = freebsd32_sysent,
125 .sv_fixup = aout_fixup,
126 .sv_sendsig = ia32_sendsig,
127 .sv_sigcode = _binary_elf_vdso32_so_1_start,
128 .sv_szsigcode = &aout_szsigcode,
129 .sv_name = "FreeBSD a.out",
130 .sv_coredump = NULL,
131 .sv_minsigstksz = MINSIGSTKSZ,
132 .sv_minuser = AOUT32_MINUSER,
133 .sv_maxuser = AOUT32_USRSTACK,
134 .sv_usrstack = AOUT32_USRSTACK,
135 .sv_psstrings = AOUT32_PS_STRINGS,
136 .sv_psstringssz = sizeof(struct freebsd32_ps_strings),
137 .sv_stackprot = VM_PROT_ALL,
138 .sv_copyout_strings = freebsd32_copyout_strings,
139 .sv_setregs = ia32_setregs,
140 .sv_fixlimit = ia32_fixlimit,
141 .sv_maxssiz = &ia32_maxssiz,
142 .sv_flags = SV_ABI_FREEBSD | SV_AOUT | SV_ILP32 | SV_SIGSYS,
143 .sv_set_syscall_retval = ia32_set_syscall_retval,
144 .sv_fetch_syscall_args = ia32_fetch_syscall_args,
145 .sv_syscallnames = freebsd32_syscallnames,
146 .sv_onexec_old = exec_onexec_old,
147 .sv_onexit = exit_onexit,
148 .sv_set_fork_retval = x86_set_fork_retval,
149 };
150
151 static void
aout_sysent(void * arg __unused)152 aout_sysent(void *arg __unused)
153 {
154 aout_szsigcode = (int)(uintptr_t)&_binary_elf_vdso32_so_1_size;
155 }
156 SYSINIT(aout_sysent, SI_SUB_EXEC, SI_ORDER_ANY, aout_sysent, NULL);
157 #else
158 #error "Only ia32 arch is supported"
159 #endif
160
161 static int
aout_fixup(uintptr_t * stack_base,struct image_params * imgp)162 aout_fixup(uintptr_t *stack_base, struct image_params *imgp)
163 {
164
165 *stack_base -= sizeof(uint32_t);
166 if (suword32((void *)*stack_base, imgp->args->argc) != 0)
167 return (EFAULT);
168 return (0);
169 }
170
171 static int
exec_aout_imgact(struct image_params * imgp)172 exec_aout_imgact(struct image_params *imgp)
173 {
174 const struct exec *a_out;
175 struct vmspace *vmspace;
176 vm_map_t map;
177 vm_object_t object;
178 vm_offset_t text_end, data_end;
179 unsigned long virtual_offset;
180 unsigned long file_offset;
181 unsigned long bss_size;
182 int error;
183
184 a_out = (const struct exec *)imgp->image_header;
185
186 /*
187 * Linux and *BSD binaries look very much alike,
188 * only the machine id is different:
189 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
190 * NetBSD is in network byte order.. ugh.
191 */
192 if (((a_out->a_midmag >> 16) & 0xff) != 0x86 &&
193 ((a_out->a_midmag >> 16) & 0xff) != 0 &&
194 ((((int)ntohl(a_out->a_midmag)) >> 16) & 0xff) != 0x86)
195 return (-1);
196
197 /*
198 * Set file/virtual offset based on a.out variant.
199 * We do two cases: host byte order and network byte order
200 * (for NetBSD compatibility)
201 */
202 switch ((int)(a_out->a_midmag & 0xffff)) {
203 case ZMAGIC:
204 virtual_offset = 0;
205 if (a_out->a_text) {
206 file_offset = PAGE_SIZE;
207 } else {
208 /* Bill's "screwball mode" */
209 file_offset = 0;
210 }
211 break;
212 case QMAGIC:
213 virtual_offset = PAGE_SIZE;
214 file_offset = 0;
215 /* Pass PS_STRINGS for BSD/OS binaries only. */
216 if (N_GETMID(*a_out) == MID_ZERO)
217 imgp->ps_strings = (void *)aout_sysvec.sv_psstrings;
218 break;
219 default:
220 /* NetBSD compatibility */
221 switch ((int)(ntohl(a_out->a_midmag) & 0xffff)) {
222 case ZMAGIC:
223 case QMAGIC:
224 virtual_offset = PAGE_SIZE;
225 file_offset = 0;
226 break;
227 default:
228 return (-1);
229 }
230 }
231
232 bss_size = roundup(a_out->a_bss, PAGE_SIZE);
233
234 /*
235 * Check various fields in header for validity/bounds.
236 */
237 if (/* entry point must lay with text region */
238 a_out->a_entry < virtual_offset ||
239 a_out->a_entry >= virtual_offset + a_out->a_text ||
240
241 /* text and data size must each be page rounded */
242 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK
243
244 #ifdef __amd64__
245 ||
246 /* overflows */
247 virtual_offset + a_out->a_text + a_out->a_data + bss_size > UINT_MAX
248 #endif
249 )
250 return (-1);
251
252 /* text + data can't exceed file size */
253 if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
254 return (EFAULT);
255
256 /*
257 * text/data/bss must not exceed limits
258 */
259 PROC_LOCK(imgp->proc);
260 if (/* text can't exceed maximum text size */
261 a_out->a_text > maxtsiz ||
262
263 /* data + bss can't exceed rlimit */
264 a_out->a_data + bss_size > lim_cur_proc(imgp->proc, RLIMIT_DATA) ||
265 racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) {
266 PROC_UNLOCK(imgp->proc);
267 return (ENOMEM);
268 }
269 PROC_UNLOCK(imgp->proc);
270
271 /*
272 * Avoid a possible deadlock if the current address space is destroyed
273 * and that address space maps the locked vnode. In the common case,
274 * the locked vnode's v_usecount is decremented but remains greater
275 * than zero. Consequently, the vnode lock is not needed by vrele().
276 * However, in cases where the vnode lock is external, such as nullfs,
277 * v_usecount may become zero.
278 */
279 VOP_UNLOCK(imgp->vp);
280
281 /*
282 * Destroy old process VM and create a new one (with a new stack)
283 */
284 error = exec_new_vmspace(imgp, &aout_sysvec);
285
286 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
287 if (error)
288 return (error);
289
290 /*
291 * The vm space can be changed by exec_new_vmspace
292 */
293 vmspace = imgp->proc->p_vmspace;
294
295 object = imgp->object;
296 map = &vmspace->vm_map;
297 vm_map_lock(map);
298 vm_object_reference(object);
299
300 text_end = virtual_offset + a_out->a_text;
301 error = vm_map_insert(map, object,
302 file_offset,
303 virtual_offset, text_end,
304 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
305 MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_VN_EXEC);
306 if (error) {
307 vm_map_unlock(map);
308 vm_object_deallocate(object);
309 return (error);
310 }
311 VOP_SET_TEXT_CHECKED(imgp->vp);
312 data_end = text_end + a_out->a_data;
313 if (a_out->a_data) {
314 vm_object_reference(object);
315 error = vm_map_insert(map, object,
316 file_offset + a_out->a_text,
317 text_end, data_end,
318 VM_PROT_ALL, VM_PROT_ALL,
319 MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_VN_EXEC);
320 if (error) {
321 vm_map_unlock(map);
322 vm_object_deallocate(object);
323 return (error);
324 }
325 VOP_SET_TEXT_CHECKED(imgp->vp);
326 }
327
328 if (bss_size) {
329 error = vm_map_insert(map, NULL, 0,
330 data_end, data_end + bss_size,
331 VM_PROT_ALL, VM_PROT_ALL, 0);
332 if (error) {
333 vm_map_unlock(map);
334 return (error);
335 }
336 }
337 vm_map_unlock(map);
338
339 /* Fill in process VM information */
340 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
341 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
342 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset;
343 vmspace->vm_daddr = (caddr_t) (uintptr_t)
344 (virtual_offset + a_out->a_text);
345
346 error = exec_map_stack(imgp);
347 if (error != 0)
348 return (error);
349
350 /* Fill in image_params */
351 imgp->interpreted = 0;
352 imgp->entry_addr = a_out->a_entry;
353
354 imgp->proc->p_sysent = &aout_sysvec;
355
356 return (0);
357 }
358
359 /*
360 * Tell kern_execve.c about it, with a little help from the linker.
361 */
362 static struct execsw aout_execsw = {
363 .ex_imgact = exec_aout_imgact,
364 .ex_name = "a.out"
365 };
366 EXEC_SET(aout, aout_execsw);
367