1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1994-1996 Søren Schmidt
5 * All rights reserved.
6 *
7 * Based heavily on /sys/kern/imgact_aout.c which is:
8 * Copyright (c) 1993, David Greenman
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/exec.h>
38 #include <sys/imgact.h>
39 #include <sys/imgact_aout.h>
40 #include <sys/kernel.h>
41 #include <sys/lock.h>
42 #include <sys/mman.h>
43 #include <sys/mutex.h>
44 #include <sys/proc.h>
45 #include <sys/racct.h>
46 #include <sys/resourcevar.h>
47 #include <sys/vnode.h>
48
49 #include <vm/vm.h>
50 #include <vm/vm_kern.h>
51 #include <vm/vm_param.h>
52 #include <vm/pmap.h>
53 #include <vm/vm_map.h>
54 #include <vm/vm_extern.h>
55
56 #include <i386/linux/linux.h>
57
58 static int exec_linux_imgact(struct image_params *iparams);
59
60 static int
61 exec_linux_imgact(struct image_params *imgp)
62 {
63 const struct exec *a_out = (const struct exec *) imgp->image_header;
64 struct vmspace *vmspace;
65 vm_offset_t vmaddr;
66 unsigned long virtual_offset, file_offset;
67 unsigned long bss_size;
68 ssize_t aresid;
69 int error;
70
71 if (((a_out->a_magic >> 16) & 0xff) != 0x64)
72 return (-1);
73
74 /*
75 * Set file/virtual offset based on a.out variant.
76 */
77 switch ((int)(a_out->a_magic & 0xffff)) {
78 case 0413:
79 virtual_offset = 0;
80 file_offset = 1024;
81 break;
82 case 0314:
83 virtual_offset = 4096;
84 file_offset = 0;
85 break;
86 default:
87 return (-1);
88 }
89 bss_size = round_page(a_out->a_bss);
90 #ifdef DEBUG
91 printf("imgact: text: %08lx, data: %08lx, bss: %08lx\n",
92 (u_long)a_out->a_text, (u_long)a_out->a_data, bss_size);
93 #endif
94
95 /*
96 * Check various fields in header for validity/bounds.
97 */
98 if (a_out->a_entry < virtual_offset ||
99 a_out->a_entry >= virtual_offset + a_out->a_text ||
100 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK)
101 return (-1);
102
103 /* text + data can't exceed file size */
104 if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
105 return (EFAULT);
106 /*
107 * text/data/bss must not exceed limits
108 */
109 PROC_LOCK(imgp->proc);
110 if (a_out->a_text > maxtsiz ||
111 a_out->a_data + bss_size > lim_cur_proc(imgp->proc, RLIMIT_DATA) ||
112 racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) {
113 PROC_UNLOCK(imgp->proc);
114 return (ENOMEM);
115 }
116 PROC_UNLOCK(imgp->proc);
117
118 VOP_UNLOCK(imgp->vp);
119
120 /*
121 * Destroy old process VM and create a new one (with a new stack)
122 */
123 error = exec_new_vmspace(imgp, &linux_sysvec);
124 if (error)
125 goto fail;
126 vmspace = imgp->proc->p_vmspace;
127
128 /*
129 * Check if file_offset page aligned,.
130 * Currently we cannot handle misaligned file offsets,
131 * and so we read in the entire image (what a waste).
132 */
133 if (file_offset & PAGE_MASK) {
134 #ifdef DEBUG
135 printf("imgact: Non page aligned binary %lu\n", file_offset);
136 #endif
137 /*
138 * Map text+data+bss read/write/execute
139 */
140 vmaddr = virtual_offset;
141 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr,
142 a_out->a_text + a_out->a_data + bss_size, 0, VMFS_NO_SPACE,
143 VM_PROT_ALL, VM_PROT_ALL, 0);
144 if (error)
145 goto fail;
146
147 error = vn_rdwr(UIO_READ, imgp->vp, (void *)vmaddr, file_offset,
148 a_out->a_text + a_out->a_data, UIO_USERSPACE, 0,
149 curthread->td_ucred, NOCRED, &aresid, curthread);
150 if (error != 0)
151 goto fail;
152 if (aresid != 0) {
153 error = ENOEXEC;
154 goto fail;
155 }
156
157 /*
158 * remove write enable on the 'text' part
159 */
160 error = vm_map_protect(&vmspace->vm_map, vmaddr,
161 vmaddr + a_out->a_text, 0, VM_PROT_EXECUTE | VM_PROT_READ,
162 VM_MAP_PROTECT_SET_MAXPROT);
163 if (error)
164 goto fail;
165 } else {
166 #ifdef DEBUG
167 printf("imgact: Page aligned binary %lu\n", file_offset);
168 #endif
169 /*
170 * Map text+data read/execute
171 */
172 vmaddr = virtual_offset;
173 error = vm_mmap(&vmspace->vm_map, &vmaddr,
174 a_out->a_text + a_out->a_data,
175 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
176 MAP_PRIVATE | MAP_FIXED, OBJT_VNODE, imgp->vp, file_offset);
177 if (error)
178 goto fail;
179
180 #ifdef DEBUG
181 printf("imgact: startaddr=%08lx, length=%08lx\n",
182 (u_long)vmaddr,
183 (u_long)a_out->a_text + (u_long)a_out->a_data);
184 #endif
185 /*
186 * allow read/write of data
187 */
188 error = vm_map_protect(&vmspace->vm_map, vmaddr + a_out->a_text,
189 vmaddr + a_out->a_text + a_out->a_data, VM_PROT_ALL, 0,
190 VM_MAP_PROTECT_SET_PROT);
191 if (error)
192 goto fail;
193
194 /*
195 * Allocate anon demand-zeroed area for uninitialized data
196 */
197 if (bss_size != 0) {
198 vmaddr = virtual_offset + a_out->a_text + a_out->a_data;
199 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr,
200 bss_size, 0, VMFS_NO_SPACE, VM_PROT_ALL, VM_PROT_ALL, 0);
201 if (error)
202 goto fail;
203 #ifdef DEBUG
204 printf("imgact: bssaddr=%08lx, length=%08lx\n", (u_long)vmaddr,
205 bss_size);
206 #endif
207 }
208 }
209 /* Fill in process VM information */
210 vmspace->vm_tsize = round_page(a_out->a_text) >> PAGE_SHIFT;
211 vmspace->vm_dsize = round_page(a_out->a_data + bss_size) >> PAGE_SHIFT;
212 vmspace->vm_taddr = (caddr_t)(void *)(uintptr_t)virtual_offset;
213 vmspace->vm_daddr =
214 (caddr_t)(void *)(uintptr_t)(virtual_offset + a_out->a_text);
215
216 /* Fill in image_params */
217 imgp->interpreted = 0;
218 imgp->entry_addr = a_out->a_entry;
219
220 imgp->proc->p_sysent = &linux_sysvec;
221
222 fail:
223 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
224 return (error);
225 }
226
227 /*
228 * Tell kern_execve.c about it, with a little help from the linker.
229 */
230 static struct execsw linux_execsw = { exec_linux_imgact, "Linux a.out" };
231 EXEC_SET(linuxaout, linux_execsw);
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