xref: /netbsd/sys/miscfs/procfs/procfs_cmdline.c (revision c4a72b64)
1 /*	$NetBSD: procfs_cmdline.c,v 1.15 2002/11/07 08:16:02 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/cdefs.h>
41 __KERNEL_RCSID(0, "$NetBSD: procfs_cmdline.c,v 1.15 2002/11/07 08:16:02 thorpej Exp $");
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/syslimits.h>
46 #include <sys/proc.h>
47 #include <sys/vnode.h>
48 #include <sys/exec.h>
49 #include <sys/malloc.h>
50 #include <miscfs/procfs/procfs.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;
66 	size_t i, 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 process_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 		free(arg, M_TEMP);
110 		return (EFAULT);
111 	}
112 	p->p_vmspace->vm_refcnt++;	/* XXX */
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)p->p_psstr;
122 	auio.uio_resid = sizeof(pss);
123 	auio.uio_segflg = UIO_SYSSPACE;
124 	auio.uio_rw = UIO_READ;
125 	auio.uio_procp = NULL;
126 	error = uvm_io(&p->p_vmspace->vm_map, &auio);
127 	if (error)
128 		goto bad;
129 
130 	/*
131 	 * Now read the address of the argument vector.
132 	 */
133 	aiov.iov_base = &argv;
134 	aiov.iov_len = sizeof(argv);
135 	auio.uio_iov = &aiov;
136 	auio.uio_iovcnt = 1;
137 	auio.uio_offset = (vaddr_t)pss.ps_argvstr;
138 	auio.uio_resid = sizeof(argv);
139 	auio.uio_segflg = UIO_SYSSPACE;
140 	auio.uio_rw = UIO_READ;
141 	auio.uio_procp = NULL;
142 	error = uvm_io(&p->p_vmspace->vm_map, &auio);
143 	if (error)
144 		goto bad;
145 
146 	/*
147 	 * Now copy in the actual argument vector, one page at a time,
148 	 * since we don't know how long the vector is (though, we do
149 	 * know how many NUL-terminated strings are in the vector).
150 	 */
151 	len = 0;
152 	count = pss.ps_nargvstr;
153 	upper_bound = round_page(uio->uio_offset + uio->uio_resid);
154 	for (; count && len < upper_bound; len += xlen) {
155 		aiov.iov_base = arg;
156 		aiov.iov_len = PAGE_SIZE;
157 		auio.uio_iov = &aiov;
158 		auio.uio_iovcnt = 1;
159 		auio.uio_offset = argv + len;
160 		xlen = PAGE_SIZE - ((argv + len) & PAGE_MASK);
161 		auio.uio_resid = xlen;
162 		auio.uio_segflg = UIO_SYSSPACE;
163 		auio.uio_rw = UIO_READ;
164 		auio.uio_procp = NULL;
165 		error = uvm_io(&p->p_vmspace->vm_map, &auio);
166 		if (error)
167 			goto bad;
168 
169 		for (i = 0; i < xlen && count != 0; i++) {
170 			if (arg[i] == '\0')
171 				count--;	/* one full string */
172 		}
173 
174 		if (count == 0)
175 			i--;		/* exclude the final NUL */
176 
177 		if (len + i > uio->uio_offset) {
178 			/* Have data in this page, copy it out */
179 			error = uiomove(arg + uio->uio_offset - len,
180 			    i + len - uio->uio_offset, uio);
181 			if (error || uio->uio_resid <= 0)
182 				break;
183 		}
184 	}
185 
186  bad:
187 	/*
188 	 * Release the process.
189 	 */
190 	uvmspace_free(p->p_vmspace);
191 
192 	free(arg, M_TEMP);
193 	return (error);
194 }
195