xref: /netbsd-src/sys/miscfs/procfs/procfs_cmdline.c (revision 195403fe387c9fc93791d682d61f225da940a563)
1 /*	$NetBSD: procfs_cmdline.c,v 1.3 1999/03/13 22:26:48 thorpej Exp $	*/
2 
3 /*
4  * Copyright (c) 1999 Jaromir Dolecek <dolecek@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 #if defined(UVM)
52 #include <uvm/uvm_extern.h>
53 #endif
54 
55 /*
56  * code for returning process's command line arguments
57  */
58 int
59 procfs_docmdline(curp, p, pfs, uio)
60 	struct proc *curp;
61 	struct proc *p;
62 	struct pfsnode *pfs;
63 	struct uio *uio;
64 {
65 	struct ps_strings pss;
66 	int xlen, len, count, error;
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 	 * XXX THIS COULD BE HANDLED MUCH MORE INTELLIGENTLY,
80 	 * XXX WITHOUT REQUIRING A 256k TEMPORARY BUFFER!
81 	 */
82 	arg = malloc(ARG_MAX, M_TEMP, M_WAITOK);
83 
84 	/*
85 	 * Zombies don't have a stack, so we can't read their psstrings.
86 	 * System processes also don't have a user stack.  This is what
87 	 * ps(1) would display.
88 	 */
89 	if (p->p_stat == SZOMB || (p->p_flag & P_SYSTEM) != 0) {
90 		snprintf(arg, sizeof(arg), "(%s)", p->p_comm);
91 		len = strlen(arg);	/* exclude last NUL */
92 		goto doio;
93 	}
94 
95 	/*
96 	 * NOTE: Don't bother doing a procfs_checkioperm() here
97 	 * because the psstrings info is available by using ps(1),
98 	 * so it's not like there's anything to protect here.
99 	 */
100 
101 	/*
102 	 * Lock the process down in memory.
103 	 */
104 #if defined(UVM)
105 	/* XXXCDC: how should locking work here? */
106 	if ((p->p_flag & P_WEXIT) || (p->p_vmspace->vm_refcnt < 1))
107 		return (EFAULT);
108 	PHOLD(p);
109 	p->p_vmspace->vm_refcnt++;	/* XXX */
110 #else
111 	PHOLD(p);
112 #endif
113 
114 	/*
115 	 * Read in the ps_strings structure.
116 	 */
117 	aiov.iov_base = &pss;
118 	aiov.iov_len = sizeof(pss);
119 	auio.uio_iov = &aiov;
120 	auio.uio_iovcnt = 1;
121 	auio.uio_offset = (vaddr_t)PS_STRINGS;
122 	auio.uio_resid = sizeof(pss);
123 	auio.uio_segflg = UIO_SYSSPACE;
124 	auio.uio_rw = UIO_READ;
125 	auio.uio_procp = NULL;
126 #if defined(UVM)
127 	error = uvm_io(&p->p_vmspace->vm_map, &auio);
128 #else
129 	error = procfs_rwmem(p, &auio);
130 #endif
131 	if (error)
132 		goto bad;
133 
134 	/*
135 	 * Now read the address of the argument vector.
136 	 */
137 	aiov.iov_base = &argv;
138 	aiov.iov_len = sizeof(argv);
139 	auio.uio_iov = &aiov;
140 	auio.uio_iovcnt = 1;
141 	auio.uio_offset = (vaddr_t)pss.ps_argvstr;
142 	auio.uio_resid = sizeof(argv);
143 	auio.uio_segflg = UIO_SYSSPACE;
144 	auio.uio_rw = UIO_READ;
145 	auio.uio_procp = NULL;
146 #if defined(UVM)
147 	error = uvm_io(&p->p_vmspace->vm_map, &auio);
148 #else
149 	error = procfs_rwmem(p, &auio);
150 #endif
151 	if (error)
152 		goto bad;
153 
154 	/*
155 	 * Now copy in the actual argument vector, one byte at a time,
156 	 * since we don't know how long the vector is (though, we do
157 	 * know how many NUL-terminated strings are in the vector).
158 	 */
159 	len = 0;
160 	count = pss.ps_nargvstr;
161 	while (count && len < ARG_MAX) {
162 		aiov.iov_base = &arg[len];
163 		aiov.iov_len = 1;
164 		auio.uio_iov = &aiov;
165 		auio.uio_iovcnt = 1;
166 		auio.uio_offset = argv + len;
167 		auio.uio_resid = 1;
168 		auio.uio_segflg = UIO_SYSSPACE;
169 		auio.uio_rw = UIO_READ;
170 		auio.uio_procp = NULL;
171 #if defined(UVM)
172 		error = uvm_io(&p->p_vmspace->vm_map, &auio);
173 #else
174 		error = procfs_rwmem(p, &auio);
175 #endif
176 		if (error)
177 			goto bad;
178 
179 		if (len > 0 && arg[len] == '\0')
180 			count--;	/* one full string */
181 		len++;
182 	}
183 	if (len > 0)
184 		len--;			/* exclude last NUL */
185 
186 	/*
187 	 * Release the process.
188 	 */
189 #if defined(UVM)
190 	PRELE(p);
191 	uvmspace_free(p->p_vmspace);
192 #else
193 	PRELE(p);
194 #endif
195 
196  doio:
197 	xlen = len - uio->uio_offset;
198 	xlen = imin(xlen, uio->uio_resid);
199 	if (xlen <= 0)
200 		error = 0;
201 	else
202 		error = uiomove(arg + uio->uio_offset, xlen, uio);
203 
204 	free(arg, M_TEMP);
205 	return (error);
206 
207  bad:
208 #if defined(UVM)
209 	PRELE(p);
210 	uvmspace_free(p->p_vmspace);
211 #else
212 	PRELE(p);
213 #endif
214 	free(arg, M_TEMP);
215 	return (error);
216 }
217