1 /* $OpenBSD: procfs_cmdline.c,v 1.8 2007/06/18 08:30:07 jasper Exp $ */
2 /* $NetBSD: procfs_cmdline.c,v 1.3 1999/03/13 22:26:48 thorpej Exp $ */
3
4 /*
5 * Copyright (c) 1999 Jaromir Dolecek <dolecek@ics.muni.cz>
6 * Copyright (c) 1999 The NetBSD Foundation, Inc.
7 * All rights reserved.
8 *
9 * This code is derived from software contributed to The NetBSD Foundation
10 * by Jaromir Dolecek.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 * must display the following acknowledgement:
22 * This product includes software developed by the NetBSD
23 * Foundation, Inc. and its contributors.
24 * 4. Neither the name of The NetBSD Foundation nor the names of its
25 * contributors may be used to endorse or promote products derived
26 * from this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
29 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
30 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
31 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
32 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
33 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
34 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
35 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
36 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
37 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
39 */
40
41 #include <sys/param.h>
42 #include <sys/types.h>
43 #include <sys/systm.h>
44 #include <sys/syslimits.h>
45 #include <sys/proc.h>
46 #include <sys/vnode.h>
47 #include <sys/exec.h>
48 #include <sys/malloc.h>
49 #include <miscfs/procfs/procfs.h>
50 #include <uvm/uvm_extern.h>
51
52 /*
53 * code for returning process's command line arguments
54 */
55 int
56 procfs_docmdline(struct proc *curp, struct proc *p, struct pfsnode *pfs, struct uio *uio)
57 {
58 struct ps_strings pss;
59 int count, error, i;
60 size_t len, xlen, upper_bound;
61 struct uio auio;
62 struct iovec aiov;
63 vaddr_t argv;
64 char *arg;
65
66 /* Don't allow writing. */
67 if (uio->uio_rw != UIO_READ)
68 return (EOPNOTSUPP);
69
70 /*
71 * Allocate a temporary buffer to hold the arguments.
72 */
73 arg = malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
74
75 /*
76 * Zombies don't have a stack, so we can't read their psstrings.
77 * System processes also don't have a user stack. This is what
78 * ps(1) would display.
79 */
80 if (P_ZOMBIE(p) || (p->p_flag & P_SYSTEM) != 0) {
81 len = snprintf(arg, PAGE_SIZE, "(%s)", p->p_comm);
82 if (uio->uio_offset >= (off_t)len)
83 error = 0;
84 else
85 error = uiomove(arg, len - uio->uio_offset, uio);
86
87 free(arg, M_TEMP);
88 return (error);
89 }
90
91 /*
92 * NOTE: Don't bother doing a process_checkioperm() here
93 * because the psstrings info is available by using ps(1),
94 * so it's not like there's anything to protect here.
95 */
96
97 /*
98 * Lock the process down in memory.
99 */
100 /* XXXCDC: how should locking work here? */
101 if ((p->p_flag & P_WEXIT) || (p->p_vmspace->vm_refcnt < 1)) {
102 free(arg, M_TEMP);
103 return (EFAULT);
104 }
105 p->p_vmspace->vm_refcnt++; /* XXX */
106
107 /*
108 * Read in the ps_strings structure.
109 */
110 aiov.iov_base = &pss;
111 aiov.iov_len = sizeof(pss);
112 auio.uio_iov = &aiov;
113 auio.uio_iovcnt = 1;
114 auio.uio_offset = (vaddr_t)PS_STRINGS;
115 auio.uio_resid = sizeof(pss);
116 auio.uio_segflg = UIO_SYSSPACE;
117 auio.uio_rw = UIO_READ;
118 auio.uio_procp = NULL;
119 error = uvm_io(&p->p_vmspace->vm_map, &auio, 0);
120 if (error)
121 goto bad;
122
123 /*
124 * Now read the address of the argument vector.
125 */
126 aiov.iov_base = &argv;
127 aiov.iov_len = sizeof(argv);
128 auio.uio_iov = &aiov;
129 auio.uio_iovcnt = 1;
130 auio.uio_offset = (vaddr_t)pss.ps_argvstr;
131 auio.uio_resid = sizeof(argv);
132 auio.uio_segflg = UIO_SYSSPACE;
133 auio.uio_rw = UIO_READ;
134 auio.uio_procp = NULL;
135 error = uvm_io(&p->p_vmspace->vm_map, &auio, 0);
136 if (error)
137 goto bad;
138
139 /*
140 * Now copy in the actual argument vector, one byte at a time,
141 * since we don't know how long the vector is (though, we do
142 * know how many NUL-terminated strings are in the vector).
143 */
144 len = 0;
145 count = pss.ps_nargvstr;
146 upper_bound = round_page(uio->uio_offset + uio->uio_resid);
147 for (; count && len < upper_bound; len += xlen) {
148 aiov.iov_base = arg;
149 aiov.iov_len = PAGE_SIZE;
150 auio.uio_iov = &aiov;
151 auio.uio_iovcnt = 1;
152 auio.uio_offset = argv + len;
153 xlen = PAGE_SIZE - ((argv + len) & PAGE_MASK);
154 auio.uio_resid = xlen;
155 auio.uio_segflg = UIO_SYSSPACE;
156 auio.uio_rw = UIO_READ;
157 auio.uio_procp = NULL;
158 error = uvm_io(&p->p_vmspace->vm_map, &auio, 0);
159 if (error)
160 goto bad;
161
162 for (i = 0; i < xlen && count != 0; i++) {
163 if (arg[i] == '\0')
164 count--; /* one full string */
165 }
166
167 if (count == 0)
168 i--; /* exclude the final NUL */
169
170 if (len + i > uio->uio_offset) {
171 /* Have data in this page, copy it out */
172 error = uiomove(arg + uio->uio_offset - len,
173 i + len - uio->uio_offset, uio);
174 if (error || uio->uio_resid <= 0)
175 break;
176 }
177 }
178
179
180 bad:
181 uvmspace_free(p->p_vmspace);
182 free(arg, M_TEMP);
183 return (error);
184 }