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_IA32 | SV_ILP32 |
94 SV_SIGSYS,
95 .sv_set_syscall_retval = cpu_set_syscall_retval,
96 .sv_fetch_syscall_args = cpu_fetch_syscall_args,
97 .sv_syscallnames = syscallnames,
98 .sv_schedtail = NULL,
99 .sv_thread_detach = NULL,
100 .sv_trap = NULL,
101 .sv_onexec_old = exec_onexec_old,
102 .sv_onexit = exit_onexit,
103 .sv_set_fork_retval = x86_set_fork_retval,
104 };
105
106 #elif defined(__amd64__)
107
108 #include "vdso_ia32_offsets.h"
109
110 extern const char _binary_elf_vdso32_so_1_start[];
111 extern const char _binary_elf_vdso32_so_1_end[];
112 extern char _binary_elf_vdso32_so_1_size;
113
114 #define AOUT32_PS_STRINGS \
115 (AOUT32_USRSTACK - sizeof(struct freebsd32_ps_strings))
116 #define AOUT32_MINUSER FREEBSD32_MINUSER
117
118 extern const char *freebsd32_syscallnames[];
119 extern u_long ia32_maxssiz;
120
121 static int aout_szsigcode;
122
123 struct sysentvec aout_sysvec = {
124 .sv_size = FREEBSD32_SYS_MAXSYSCALL,
125 .sv_table = freebsd32_sysent,
126 .sv_fixup = aout_fixup,
127 .sv_sendsig = ia32_sendsig,
128 .sv_sigcode = _binary_elf_vdso32_so_1_start,
129 .sv_szsigcode = &aout_szsigcode,
130 .sv_name = "FreeBSD a.out",
131 .sv_coredump = NULL,
132 .sv_minsigstksz = MINSIGSTKSZ,
133 .sv_minuser = AOUT32_MINUSER,
134 .sv_maxuser = AOUT32_USRSTACK,
135 .sv_usrstack = AOUT32_USRSTACK,
136 .sv_psstrings = AOUT32_PS_STRINGS,
137 .sv_psstringssz = sizeof(struct freebsd32_ps_strings),
138 .sv_stackprot = VM_PROT_ALL,
139 .sv_copyout_strings = freebsd32_copyout_strings,
140 .sv_setregs = ia32_setregs,
141 .sv_fixlimit = ia32_fixlimit,
142 .sv_maxssiz = &ia32_maxssiz,
143 .sv_flags = SV_ABI_FREEBSD | SV_AOUT | SV_IA32 | SV_ILP32 |
144 SV_SIGSYS,
145 .sv_set_syscall_retval = ia32_set_syscall_retval,
146 .sv_fetch_syscall_args = ia32_fetch_syscall_args,
147 .sv_syscallnames = freebsd32_syscallnames,
148 .sv_onexec_old = exec_onexec_old,
149 .sv_onexit = exit_onexit,
150 .sv_set_fork_retval = x86_set_fork_retval,
151 };
152
153 static void
aout_sysent(void * arg __unused)154 aout_sysent(void *arg __unused)
155 {
156 aout_szsigcode = (int)(uintptr_t)&_binary_elf_vdso32_so_1_size;
157 }
158 SYSINIT(aout_sysent, SI_SUB_EXEC, SI_ORDER_ANY, aout_sysent, NULL);
159 #else
160 #error "Only ia32 arch is supported"
161 #endif
162
163 static int
aout_fixup(uintptr_t * stack_base,struct image_params * imgp)164 aout_fixup(uintptr_t *stack_base, struct image_params *imgp)
165 {
166
167 *stack_base -= sizeof(uint32_t);
168 if (suword32((void *)*stack_base, imgp->args->argc) != 0)
169 return (EFAULT);
170 return (0);
171 }
172
173 static int
exec_aout_imgact(struct image_params * imgp)174 exec_aout_imgact(struct image_params *imgp)
175 {
176 const struct exec *a_out;
177 struct vmspace *vmspace;
178 vm_map_t map;
179 vm_object_t object;
180 vm_offset_t text_end, data_end;
181 unsigned long virtual_offset;
182 unsigned long file_offset;
183 unsigned long bss_size;
184 int error;
185
186 a_out = (const struct exec *)imgp->image_header;
187
188 /*
189 * Linux and *BSD binaries look very much alike,
190 * only the machine id is different:
191 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
192 * NetBSD is in network byte order.. ugh.
193 */
194 if (((a_out->a_midmag >> 16) & 0xff) != 0x86 &&
195 ((a_out->a_midmag >> 16) & 0xff) != 0 &&
196 ((((int)ntohl(a_out->a_midmag)) >> 16) & 0xff) != 0x86)
197 return (-1);
198
199 /*
200 * Set file/virtual offset based on a.out variant.
201 * We do two cases: host byte order and network byte order
202 * (for NetBSD compatibility)
203 */
204 switch ((int)(a_out->a_midmag & 0xffff)) {
205 case ZMAGIC:
206 virtual_offset = 0;
207 if (a_out->a_text) {
208 file_offset = PAGE_SIZE;
209 } else {
210 /* Bill's "screwball mode" */
211 file_offset = 0;
212 }
213 break;
214 case QMAGIC:
215 virtual_offset = PAGE_SIZE;
216 file_offset = 0;
217 /* Pass PS_STRINGS for BSD/OS binaries only. */
218 if (N_GETMID(*a_out) == MID_ZERO)
219 imgp->ps_strings = (void *)aout_sysvec.sv_psstrings;
220 break;
221 default:
222 /* NetBSD compatibility */
223 switch ((int)(ntohl(a_out->a_midmag) & 0xffff)) {
224 case ZMAGIC:
225 case QMAGIC:
226 virtual_offset = PAGE_SIZE;
227 file_offset = 0;
228 break;
229 default:
230 return (-1);
231 }
232 }
233
234 bss_size = roundup(a_out->a_bss, PAGE_SIZE);
235
236 /*
237 * Check various fields in header for validity/bounds.
238 */
239 if (/* entry point must lay with text region */
240 a_out->a_entry < virtual_offset ||
241 a_out->a_entry >= virtual_offset + a_out->a_text ||
242
243 /* text and data size must each be page rounded */
244 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK
245
246 #ifdef __amd64__
247 ||
248 /* overflows */
249 virtual_offset + a_out->a_text + a_out->a_data + bss_size > UINT_MAX
250 #endif
251 )
252 return (-1);
253
254 /* text + data can't exceed file size */
255 if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
256 return (EFAULT);
257
258 /*
259 * text/data/bss must not exceed limits
260 */
261 PROC_LOCK(imgp->proc);
262 if (/* text can't exceed maximum text size */
263 a_out->a_text > maxtsiz ||
264
265 /* data + bss can't exceed rlimit */
266 a_out->a_data + bss_size > lim_cur_proc(imgp->proc, RLIMIT_DATA) ||
267 racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) {
268 PROC_UNLOCK(imgp->proc);
269 return (ENOMEM);
270 }
271 PROC_UNLOCK(imgp->proc);
272
273 /*
274 * Avoid a possible deadlock if the current address space is destroyed
275 * and that address space maps the locked vnode. In the common case,
276 * the locked vnode's v_usecount is decremented but remains greater
277 * than zero. Consequently, the vnode lock is not needed by vrele().
278 * However, in cases where the vnode lock is external, such as nullfs,
279 * v_usecount may become zero.
280 */
281 VOP_UNLOCK(imgp->vp);
282
283 /*
284 * Destroy old process VM and create a new one (with a new stack)
285 */
286 error = exec_new_vmspace(imgp, &aout_sysvec);
287
288 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
289 if (error)
290 return (error);
291
292 /*
293 * The vm space can be changed by exec_new_vmspace
294 */
295 vmspace = imgp->proc->p_vmspace;
296
297 object = imgp->object;
298 map = &vmspace->vm_map;
299 vm_map_lock(map);
300 vm_object_reference(object);
301
302 text_end = virtual_offset + a_out->a_text;
303 error = vm_map_insert(map, object,
304 file_offset,
305 virtual_offset, text_end,
306 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
307 MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_VN_EXEC);
308 if (error) {
309 vm_map_unlock(map);
310 vm_object_deallocate(object);
311 return (error);
312 }
313 VOP_SET_TEXT_CHECKED(imgp->vp);
314 data_end = text_end + a_out->a_data;
315 if (a_out->a_data) {
316 vm_object_reference(object);
317 error = vm_map_insert(map, object,
318 file_offset + a_out->a_text,
319 text_end, data_end,
320 VM_PROT_ALL, VM_PROT_ALL,
321 MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_VN_EXEC);
322 if (error) {
323 vm_map_unlock(map);
324 vm_object_deallocate(object);
325 return (error);
326 }
327 VOP_SET_TEXT_CHECKED(imgp->vp);
328 }
329
330 if (bss_size) {
331 error = vm_map_insert(map, NULL, 0,
332 data_end, data_end + bss_size,
333 VM_PROT_ALL, VM_PROT_ALL, 0);
334 if (error) {
335 vm_map_unlock(map);
336 return (error);
337 }
338 }
339 vm_map_unlock(map);
340
341 /* Fill in process VM information */
342 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
343 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
344 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset;
345 vmspace->vm_daddr = (caddr_t) (uintptr_t)
346 (virtual_offset + a_out->a_text);
347
348 error = exec_map_stack(imgp);
349 if (error != 0)
350 return (error);
351
352 /* Fill in image_params */
353 imgp->interpreted = 0;
354 imgp->entry_addr = a_out->a_entry;
355
356 imgp->proc->p_sysent = &aout_sysvec;
357
358 return (0);
359 }
360
361 /*
362 * Tell kern_execve.c about it, with a little help from the linker.
363 */
364 static struct execsw aout_execsw = {
365 .ex_imgact = exec_aout_imgact,
366 .ex_name = "a.out"
367 };
368 EXEC_SET(aout, aout_execsw);
369