1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
33 #include <sys/systm.h>
34 #include <sys/exec.h>
35 #include <sys/imgact.h>
36 #include <sys/imgact_aout.h>
37 #include <sys/kernel.h>
38 #include <sys/lock.h>
39 #include <sys/mman.h>
40 #include <sys/mutex.h>
41 #include <sys/proc.h>
42 #include <sys/racct.h>
43 #include <sys/resourcevar.h>
44 #include <sys/vnode.h>
45
46 #include <vm/vm.h>
47 #include <vm/vm_kern.h>
48 #include <vm/vm_param.h>
49 #include <vm/pmap.h>
50 #include <vm/vm_map.h>
51 #include <vm/vm_extern.h>
52
53 #include <i386/linux/linux.h>
54
55 static int exec_linux_imgact(struct image_params *iparams);
56
57 static int
exec_linux_imgact(struct image_params * imgp)58 exec_linux_imgact(struct image_params *imgp)
59 {
60 const struct exec *a_out = (const struct exec *) imgp->image_header;
61 struct vmspace *vmspace;
62 vm_offset_t vmaddr;
63 unsigned long virtual_offset, file_offset;
64 unsigned long bss_size;
65 ssize_t aresid;
66 int error;
67
68 if (((a_out->a_magic >> 16) & 0xff) != 0x64)
69 return (-1);
70
71 /*
72 * Set file/virtual offset based on a.out variant.
73 */
74 switch ((int)(a_out->a_magic & 0xffff)) {
75 case 0413:
76 virtual_offset = 0;
77 file_offset = 1024;
78 break;
79 case 0314:
80 virtual_offset = 4096;
81 file_offset = 0;
82 break;
83 default:
84 return (-1);
85 }
86 bss_size = round_page(a_out->a_bss);
87 #ifdef DEBUG
88 printf("imgact: text: %08lx, data: %08lx, bss: %08lx\n",
89 (u_long)a_out->a_text, (u_long)a_out->a_data, bss_size);
90 #endif
91
92 /*
93 * Check various fields in header for validity/bounds.
94 */
95 if (a_out->a_entry < virtual_offset ||
96 a_out->a_entry >= virtual_offset + a_out->a_text ||
97 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK)
98 return (-1);
99
100 /* text + data can't exceed file size */
101 if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
102 return (EFAULT);
103 /*
104 * text/data/bss must not exceed limits
105 */
106 PROC_LOCK(imgp->proc);
107 if (a_out->a_text > maxtsiz ||
108 a_out->a_data + bss_size > lim_cur_proc(imgp->proc, RLIMIT_DATA) ||
109 racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) {
110 PROC_UNLOCK(imgp->proc);
111 return (ENOMEM);
112 }
113 PROC_UNLOCK(imgp->proc);
114
115 VOP_UNLOCK(imgp->vp);
116
117 /*
118 * Destroy old process VM and create a new one (with a new stack)
119 */
120 error = exec_new_vmspace(imgp, &linux_sysvec);
121 if (error)
122 goto fail;
123 vmspace = imgp->proc->p_vmspace;
124
125 /*
126 * Check if file_offset page aligned,.
127 * Currently we cannot handle misaligned file offsets,
128 * and so we read in the entire image (what a waste).
129 */
130 if (file_offset & PAGE_MASK) {
131 #ifdef DEBUG
132 printf("imgact: Non page aligned binary %lu\n", file_offset);
133 #endif
134 /*
135 * Map text+data+bss read/write/execute
136 */
137 vmaddr = virtual_offset;
138 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr,
139 a_out->a_text + a_out->a_data + bss_size, 0, VMFS_NO_SPACE,
140 VM_PROT_ALL, VM_PROT_ALL, 0);
141 if (error)
142 goto fail;
143
144 error = vn_rdwr(UIO_READ, imgp->vp, (void *)vmaddr, file_offset,
145 a_out->a_text + a_out->a_data, UIO_USERSPACE, 0,
146 curthread->td_ucred, NOCRED, &aresid, curthread);
147 if (error != 0)
148 goto fail;
149 if (aresid != 0) {
150 error = ENOEXEC;
151 goto fail;
152 }
153
154 /*
155 * remove write enable on the 'text' part
156 */
157 error = vm_map_protect(&vmspace->vm_map, vmaddr,
158 vmaddr + a_out->a_text, 0, VM_PROT_EXECUTE | VM_PROT_READ,
159 VM_MAP_PROTECT_SET_MAXPROT);
160 if (error)
161 goto fail;
162 } else {
163 #ifdef DEBUG
164 printf("imgact: Page aligned binary %lu\n", file_offset);
165 #endif
166 /*
167 * Map text+data read/execute
168 */
169 vmaddr = virtual_offset;
170 error = vm_mmap(&vmspace->vm_map, &vmaddr,
171 a_out->a_text + a_out->a_data,
172 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
173 MAP_PRIVATE | MAP_FIXED, OBJT_VNODE, imgp->vp, file_offset);
174 if (error)
175 goto fail;
176
177 #ifdef DEBUG
178 printf("imgact: startaddr=%08lx, length=%08lx\n",
179 (u_long)vmaddr,
180 (u_long)a_out->a_text + (u_long)a_out->a_data);
181 #endif
182 /*
183 * allow read/write of data
184 */
185 error = vm_map_protect(&vmspace->vm_map, vmaddr + a_out->a_text,
186 vmaddr + a_out->a_text + a_out->a_data, VM_PROT_ALL, 0,
187 VM_MAP_PROTECT_SET_PROT);
188 if (error)
189 goto fail;
190
191 /*
192 * Allocate anon demand-zeroed area for uninitialized data
193 */
194 if (bss_size != 0) {
195 vmaddr = virtual_offset + a_out->a_text + a_out->a_data;
196 error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr,
197 bss_size, 0, VMFS_NO_SPACE, VM_PROT_ALL, VM_PROT_ALL, 0);
198 if (error)
199 goto fail;
200 #ifdef DEBUG
201 printf("imgact: bssaddr=%08lx, length=%08lx\n", (u_long)vmaddr,
202 bss_size);
203 #endif
204 }
205 }
206 /* Fill in process VM information */
207 vmspace->vm_tsize = round_page(a_out->a_text) >> PAGE_SHIFT;
208 vmspace->vm_dsize = round_page(a_out->a_data + bss_size) >> PAGE_SHIFT;
209 vmspace->vm_taddr = (caddr_t)(void *)(uintptr_t)virtual_offset;
210 vmspace->vm_daddr =
211 (caddr_t)(void *)(uintptr_t)(virtual_offset + a_out->a_text);
212
213 error = exec_map_stack(imgp);
214 if (error != 0)
215 goto fail;
216
217 /* Fill in image_params */
218 imgp->interpreted = 0;
219 imgp->entry_addr = a_out->a_entry;
220
221 imgp->proc->p_sysent = &linux_sysvec;
222
223 fail:
224 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
225 return (error);
226 }
227
228 /*
229 * Tell kern_execve.c about it, with a little help from the linker.
230 */
231 static struct execsw linux_execsw = { exec_linux_imgact, "Linux a.out" };
232 EXEC_SET(linuxaout, linux_execsw);
233