1/*-
2 * Copyright (c) 1994-1996 Søren Schmidt
3 * All rights reserved.
4 *
5 * Based heavily on /sys/kern/imgact_aout.c which is:
6 * Copyright (c) 1993, David Greenman
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer
13 *    in this position and unchanged.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. The name of the author may not be used to endorse or promote products
18 *    derived from this software without specific prior written permission
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 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
58static int	exec_linux_imgact(struct image_params *iparams);
59
60static int
61exec_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(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, 0);
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,
161			       vmaddr,
162			       vmaddr + a_out->a_text,
163			       VM_PROT_EXECUTE|VM_PROT_READ,
164			       TRUE);
165	if (error)
166	    goto fail;
167    }
168    else {
169#ifdef DEBUG
170	printf("imgact: Page aligned binary %lu\n", file_offset);
171#endif
172	/*
173	 * Map text+data read/execute
174	 */
175	vmaddr = virtual_offset;
176	error = vm_mmap(&vmspace->vm_map, &vmaddr,
177			a_out->a_text + a_out->a_data,
178			VM_PROT_READ | VM_PROT_EXECUTE,
179			VM_PROT_ALL,
180			MAP_PRIVATE | MAP_FIXED,
181			OBJT_VNODE,
182			imgp->vp, file_offset);
183	if (error)
184	    goto fail;
185
186#ifdef DEBUG
187	printf("imgact: startaddr=%08lx, length=%08lx\n",
188	    (u_long)vmaddr, (u_long)a_out->a_text + (u_long)a_out->a_data);
189#endif
190	/*
191	 * allow read/write of data
192	 */
193	error = vm_map_protect(&vmspace->vm_map,
194			       vmaddr + a_out->a_text,
195			       vmaddr + a_out->a_text + a_out->a_data,
196			       VM_PROT_ALL,
197			       FALSE);
198	if (error)
199	    goto fail;
200
201	/*
202	 * Allocate anon demand-zeroed area for uninitialized data
203	 */
204	if (bss_size != 0) {
205	    vmaddr = virtual_offset + a_out->a_text + a_out->a_data;
206	    error = vm_map_find(&vmspace->vm_map, NULL, 0, &vmaddr,
207		bss_size, 0, VMFS_NO_SPACE, VM_PROT_ALL, VM_PROT_ALL, 0);
208	    if (error)
209		goto fail;
210#ifdef DEBUG
211	    printf("imgact: bssaddr=%08lx, length=%08lx\n",
212		(u_long)vmaddr, bss_size);
213#endif
214
215	}
216    }
217    /* Fill in process VM information */
218    vmspace->vm_tsize = round_page(a_out->a_text) >> PAGE_SHIFT;
219    vmspace->vm_dsize = round_page(a_out->a_data + bss_size) >> PAGE_SHIFT;
220    vmspace->vm_taddr = (caddr_t)(void *)(uintptr_t)virtual_offset;
221    vmspace->vm_daddr = (caddr_t)(void *)(uintptr_t)
222	(virtual_offset + a_out->a_text);
223
224    /* Fill in image_params */
225    imgp->interpreted = 0;
226    imgp->entry_addr = a_out->a_entry;
227
228    imgp->proc->p_sysent = &linux_sysvec;
229
230fail:
231    vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
232    return (error);
233}
234
235/*
236 * Tell kern_execve.c about it, with a little help from the linker.
237 */
238static struct execsw linux_execsw = { exec_linux_imgact, "linux a.out" };
239EXEC_SET(linuxaout, linux_execsw);
240