xref: /freebsd/sys/fs/procfs/procfs.c (revision acd3428b7d3e94cef0e1881c868cb4b131d4ff41)
1 /*-
2  * Copyright (c) 2001 Dag-Erling Sm�rgrav
3  * Copyright (c) 1993 Jan-Simon Pendry
4  * Copyright (c) 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Jan-Simon Pendry.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)procfs_vfsops.c	8.7 (Berkeley) 5/10/95
39  *
40  * $FreeBSD$
41  */
42 
43 #include <sys/param.h>
44 #include <sys/queue.h>
45 #include <sys/exec.h>
46 #include <sys/lock.h>
47 #include <sys/kernel.h>
48 #include <sys/malloc.h>
49 #include <sys/mount.h>
50 #include <sys/mutex.h>
51 #include <sys/proc.h>
52 #include <sys/sbuf.h>
53 #include <sys/sysproto.h>
54 #include <sys/systm.h>
55 #include <sys/vnode.h>
56 
57 #include <vm/vm.h>
58 #include <vm/pmap.h>
59 #include <vm/vm_param.h>
60 
61 #include <fs/pseudofs/pseudofs.h>
62 #include <fs/procfs/procfs.h>
63 
64 /*
65  * Filler function for proc/pid/self
66  */
67 int
68 procfs_doprocfile(PFS_FILL_ARGS)
69 {
70 	char *fullpath = "unknown";
71 	char *freepath = NULL;
72 
73 	vn_lock(p->p_textvp, LK_EXCLUSIVE | LK_RETRY, td);
74 	vn_fullpath(td, p->p_textvp, &fullpath, &freepath);
75 	VOP_UNLOCK(p->p_textvp, 0, td);
76 	sbuf_printf(sb, "%s", fullpath);
77 	if (freepath)
78 		free(freepath, M_TEMP);
79 	return (0);
80 }
81 
82 /*
83  * Filler function for proc/curproc
84  */
85 int
86 procfs_docurproc(PFS_FILL_ARGS)
87 {
88 	sbuf_printf(sb, "%ld", (long)td->td_proc->p_pid);
89 	return (0);
90 }
91 
92 /*
93  * Adjust mode for some nodes that need it
94  */
95 int
96 procfs_attr(PFS_ATTR_ARGS)
97 {
98 	PROC_LOCK_ASSERT(p, MA_OWNED);
99 
100 	/* XXX inefficient, split into separate functions */
101 	if (strcmp(pn->pn_name, "ctl") == 0 ||
102 	    strcmp(pn->pn_name, "note") == 0 ||
103 	    strcmp(pn->pn_name, "notepg") == 0)
104 		vap->va_mode = 0200;
105 	else if (strcmp(pn->pn_name, "mem") == 0 ||
106 	    strcmp(pn->pn_name, "regs") == 0 ||
107 	    strcmp(pn->pn_name, "dbregs") == 0 ||
108 	    strcmp(pn->pn_name, "fpregs") == 0)
109 		vap->va_mode = 0600;
110 
111 	if ((p->p_flag & P_SUGID) && pn->pn_type != pfstype_procdir)
112 		vap->va_mode = 0;
113 
114 	vap->va_uid = p->p_ucred->cr_uid;
115 	vap->va_gid = p->p_ucred->cr_gid;
116 
117 	return (0);
118 }
119 
120 /*
121  * Visibility: some files only exist for non-system processes
122  * Non-static because linprocfs uses it.
123  */
124 int
125 procfs_notsystem(PFS_VIS_ARGS)
126 {
127 	PROC_LOCK_ASSERT(p, MA_OWNED);
128 	return ((p->p_flag & P_SYSTEM) == 0);
129 }
130 
131 /*
132  * Visibility: some files are only visible to process that can debug
133  * the target process.
134  */
135 int
136 procfs_candebug(PFS_VIS_ARGS)
137 {
138 	PROC_LOCK_ASSERT(p, MA_OWNED);
139 	return ((p->p_flag & P_SYSTEM) == 0 && p_candebug(td, p) == 0);
140 }
141 
142 /*
143  * Constructor
144  */
145 static int
146 procfs_init(PFS_INIT_ARGS)
147 {
148 	struct pfs_node *root;
149 	struct pfs_node *dir;
150 	struct pfs_node *node;
151 
152 	root = pi->pi_root;
153 
154 	pfs_create_link(root, "curproc", procfs_docurproc,
155 	    NULL, NULL, 0);
156 
157 	dir = pfs_create_dir(root, "pid",
158 	    procfs_attr, NULL, PFS_PROCDEP);
159 	pfs_create_file(dir, "cmdline", procfs_doproccmdline,
160 	    NULL, NULL, PFS_RD);
161 	pfs_create_file(dir, "ctl", procfs_doprocctl,
162 	    procfs_attr, NULL, PFS_WR);
163 	pfs_create_file(dir, "dbregs", procfs_doprocdbregs,
164 	    procfs_attr, procfs_candebug, PFS_RDWR|PFS_RAW);
165 	pfs_create_file(dir, "etype", procfs_doproctype,
166 	    NULL, NULL, PFS_RD);
167 	pfs_create_file(dir, "fpregs", procfs_doprocfpregs,
168 	    procfs_attr, procfs_candebug, PFS_RDWR|PFS_RAW);
169 	pfs_create_file(dir, "map", procfs_doprocmap,
170 	    NULL, procfs_notsystem, PFS_RD);
171 	node = pfs_create_file(dir, "mem", procfs_doprocmem,
172 	    procfs_attr, procfs_candebug, PFS_RDWR|PFS_RAW);
173 	node->pn_ioctl = procfs_ioctl;
174 	node->pn_close = procfs_close;
175 	pfs_create_file(dir, "note", procfs_doprocnote,
176 	    procfs_attr, procfs_candebug, PFS_WR);
177 	pfs_create_file(dir, "notepg", procfs_doprocnote,
178 	    procfs_attr, procfs_candebug, PFS_WR);
179 	pfs_create_file(dir, "regs", procfs_doprocregs,
180 	    procfs_attr, procfs_candebug, PFS_RDWR|PFS_RAW);
181 	pfs_create_file(dir, "rlimit", procfs_doprocrlimit,
182 	    NULL, NULL, PFS_RD);
183 	pfs_create_file(dir, "status", procfs_doprocstatus,
184 	    NULL, NULL, PFS_RD);
185 
186 	pfs_create_link(dir, "file", procfs_doprocfile,
187 	    NULL, procfs_notsystem, 0);
188 
189 	return (0);
190 }
191 
192 /*
193  * Destructor
194  */
195 static int
196 procfs_uninit(PFS_INIT_ARGS)
197 {
198 	/* nothing to do, pseudofs will GC */
199 	return (0);
200 }
201 
202 PSEUDOFS(procfs, 1);
203