1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
/* $OpenBSD: compat_util.c,v 1.15 2015/01/26 22:51:37 kettenis Exp $ */
/* $NetBSD: compat_util.c,v 1.4 1996/03/14 19:31:45 christos Exp $ */
/*
* Copyright (c) 1994 Christos Zoulas
* Copyright (c) 1995 Frank van der Linden
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/filedesc.h>
#include <sys/ioctl.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/signalvar.h>
#include <sys/vnode.h>
#include <uvm/uvm_extern.h>
#include <compat/common/compat_util.h>
/*
* Search an alternate path before passing pathname arguments on
* to system calls. Useful for keeping a separate 'emulation tree'.
*
* If cflag is set, we check if an attempt can be made to create
* the named file, i.e. we check if the directory it should
* be in exists.
*/
int
emul_find(struct proc *p, caddr_t *sgp, const char *prefix,
char *path, char **pbuf, int cflag)
{
struct nameidata nd;
struct nameidata ndroot;
struct vattr vat;
struct vattr vatroot;
int error;
char *ptr, *buf, *cp;
const char *pr;
size_t sz, len;
buf = (char *) malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
*pbuf = path;
for (ptr = buf, pr = prefix; (*ptr = *pr) != '\0'; ptr++, pr++)
continue;
sz = MAXPATHLEN - (ptr - buf);
/*
* If sgp is not given then the path is already in kernel space
*/
if (sgp == NULL)
error = copystr(path, ptr, sz, &len);
else
error = copyinstr(path, ptr, sz, &len);
if (error)
goto bad;
if (*ptr != '/') {
error = EINVAL;
goto bad;
}
/*
* We know that there is a / somewhere in this pathname.
* Search backwards for it, to find the file's parent dir
* to see if it exists in the alternate tree. If it does,
* and we want to create a file (cflag is set). We don't
* need to worry about the root comparison in this case.
*/
if (cflag) {
for (cp = &ptr[len] - 1; *cp != '/'; cp--)
;
*cp = '\0';
NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, p);
if ((error = namei(&nd)) != 0)
goto bad;
*cp = '/';
} else {
NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, p);
if ((error = namei(&nd)) != 0)
goto bad;
/*
* We now compare the vnode of the emulation root to the one
* vnode asked. If they resolve to be the same, then we
* ignore the match so that the real root gets used.
* This avoids the problem of traversing "../.." to find the
* root directory and never finding it, because "/" resolves
* to the emulation root directory. This is expensive :-(
*/
/* XXX: prototype should have const here for NDINIT */
NDINIT(&ndroot, LOOKUP, FOLLOW, UIO_SYSSPACE, prefix, p);
if ((error = namei(&ndroot)) != 0)
goto bad2;
if ((error = VOP_GETATTR(nd.ni_vp, &vat, p->p_ucred, p)) != 0)
goto bad3;
if ((error = VOP_GETATTR(ndroot.ni_vp, &vatroot, p->p_ucred, p))
!= 0)
goto bad3;
if (vat.va_fsid == vatroot.va_fsid &&
vat.va_fileid == vatroot.va_fileid) {
error = ENOENT;
goto bad3;
}
}
if (sgp == NULL)
*pbuf = buf;
else {
sz = &ptr[len] - buf;
*pbuf = stackgap_alloc(sgp, sz + 1);
if (*pbuf == NULL) {
error = ENAMETOOLONG;
goto bad;
}
if ((error = copyout(buf, *pbuf, sz)) != 0) {
*pbuf = path;
goto bad;
}
free(buf, M_TEMP, 0);
}
vrele(nd.ni_vp);
if (!cflag)
vrele(ndroot.ni_vp);
return error;
bad3:
vrele(ndroot.ni_vp);
bad2:
vrele(nd.ni_vp);
bad:
free(buf, M_TEMP, 0);
return error;
}
caddr_t
stackgap_init(struct proc *p)
{
struct process *pr = p->p_p;
if (pr->ps_stackgap == 0) {
if (uvm_map(&pr->ps_vmspace->vm_map, &pr->ps_stackgap,
round_page(STACKGAPLEN), NULL, 0, 0,
UVM_MAPFLAG(PROT_READ | PROT_WRITE, PROT_READ | PROT_WRITE,
MAP_INHERIT_COPY, MADV_RANDOM, UVM_FLAG_COPYONW)))
sigexit(p, SIGILL);
}
return (caddr_t)pr->ps_stackgap;
}
void *
stackgap_alloc(caddr_t *sgp, size_t sz)
{
void *n = (void *) *sgp;
caddr_t nsgp;
sz = ALIGN(sz);
nsgp = *sgp + sz;
if (nsgp > (caddr_t)trunc_page((vaddr_t)n) + STACKGAPLEN)
return NULL;
*sgp = nsgp;
return n;
}
|
