procfs_cmdline.c revision 1.7 1 /* $NetBSD: procfs_cmdline.c,v 1.7 2000/05/16 13:45:25 simonb Exp $ */
2
3 /*
4 * Copyright (c) 1999 Jaromir Dolecek <dolecek (at) ics.muni.cz>
5 * Copyright (c) 1999 The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Jaromir Dolecek.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the NetBSD
22 * Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 * contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40 #include <sys/param.h>
41 #include <sys/types.h>
42 #include <sys/systm.h>
43 #include <sys/syslimits.h>
44 #include <sys/proc.h>
45 #include <sys/vnode.h>
46 #include <sys/exec.h>
47 #include <sys/malloc.h>
48 #include <miscfs/procfs/procfs.h>
49
50 #include <vm/vm.h>
51
52 #include <uvm/uvm_extern.h>
53
54 /*
55 * code for returning process's command line arguments
56 */
57 int
58 procfs_docmdline(curp, p, pfs, uio)
59 struct proc *curp;
60 struct proc *p;
61 struct pfsnode *pfs;
62 struct uio *uio;
63 {
64 struct ps_strings pss;
65 int count, error, i;
66 size_t len, xlen, upper_bound;
67 struct uio auio;
68 struct iovec aiov;
69 vaddr_t argv;
70 char *arg;
71
72 /* Don't allow writing. */
73 if (uio->uio_rw != UIO_READ)
74 return (EOPNOTSUPP);
75
76 /*
77 * Allocate a temporary buffer to hold the arguments.
78 */
79 arg = malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
80
81 /*
82 * Zombies don't have a stack, so we can't read their psstrings.
83 * System processes also don't have a user stack. This is what
84 * ps(1) would display.
85 */
86 if (P_ZOMBIE(p) || (p->p_flag & P_SYSTEM) != 0) {
87 len = snprintf(arg, PAGE_SIZE, "(%s)", p->p_comm);
88 xlen = len - uio->uio_offset;
89 if (xlen <= 0)
90 error = 0;
91 else
92 error = uiomove(arg, xlen, uio);
93
94 free(arg, M_TEMP);
95 return (error);
96 }
97
98 /*
99 * NOTE: Don't bother doing a procfs_checkioperm() here
100 * because the psstrings info is available by using ps(1),
101 * so it's not like there's anything to protect here.
102 */
103
104 /*
105 * Lock the process down in memory.
106 */
107 /* XXXCDC: how should locking work here? */
108 if ((p->p_flag & P_WEXIT) || (p->p_vmspace->vm_refcnt < 1))
109 return (EFAULT);
110 PHOLD(p);
111 p->p_vmspace->vm_refcnt++; /* XXX */
112
113 /*
114 * Read in the ps_strings structure.
115 */
116 aiov.iov_base = &pss;
117 aiov.iov_len = sizeof(pss);
118 auio.uio_iov = &aiov;
119 auio.uio_iovcnt = 1;
120 auio.uio_offset = (vaddr_t)PS_STRINGS;
121 auio.uio_resid = sizeof(pss);
122 auio.uio_segflg = UIO_SYSSPACE;
123 auio.uio_rw = UIO_READ;
124 auio.uio_procp = NULL;
125 error = uvm_io(&p->p_vmspace->vm_map, &auio);
126 if (error)
127 goto bad;
128
129 /*
130 * Now read the address of the argument vector.
131 */
132 aiov.iov_base = &argv;
133 aiov.iov_len = sizeof(argv);
134 auio.uio_iov = &aiov;
135 auio.uio_iovcnt = 1;
136 auio.uio_offset = (vaddr_t)pss.ps_argvstr;
137 auio.uio_resid = sizeof(argv);
138 auio.uio_segflg = UIO_SYSSPACE;
139 auio.uio_rw = UIO_READ;
140 auio.uio_procp = NULL;
141 error = uvm_io(&p->p_vmspace->vm_map, &auio);
142 if (error)
143 goto bad;
144
145 /*
146 * Now copy in the actual argument vector, one page at a time,
147 * since we don't know how long the vector is (though, we do
148 * know how many NUL-terminated strings are in the vector).
149 */
150 len = 0;
151 count = pss.ps_nargvstr;
152 upper_bound = round_page(uio->uio_offset + uio->uio_resid);
153 for (; count && len < upper_bound; len += xlen) {
154 aiov.iov_base = arg;
155 aiov.iov_len = PAGE_SIZE;
156 auio.uio_iov = &aiov;
157 auio.uio_iovcnt = 1;
158 auio.uio_offset = argv + len;
159 xlen = PAGE_SIZE - ((argv + len) & PAGE_MASK);
160 auio.uio_resid = xlen;
161 auio.uio_segflg = UIO_SYSSPACE;
162 auio.uio_rw = UIO_READ;
163 auio.uio_procp = NULL;
164 error = uvm_io(&p->p_vmspace->vm_map, &auio);
165 if (error)
166 goto bad;
167
168 for (i = 0; i < xlen && count != 0; i++) {
169 if (arg[i] == '\0')
170 count--; /* one full string */
171 }
172
173 if (count == 0)
174 i--; /* exclude the final NUL */
175
176 if (len + i > uio->uio_offset) {
177 /* Have data in this page, copy it out */
178 error = uiomove(arg + uio->uio_offset - len,
179 i + len - uio->uio_offset, uio);
180 if (error || uio->uio_resid <= 0)
181 break;
182 }
183 }
184
185 bad:
186 /*
187 * Release the process.
188 */
189 PRELE(p);
190 uvmspace_free(p->p_vmspace);
191
192 free(arg, M_TEMP);
193 return (error);
194 }
195