xref: /freebsd/sys/fs/procfs/procfs.c (revision cbd30a72ca196976c1c700400ecd424baa1b9c16)
1 /*-
2  * Copyright (c) 2001 Dag-Erling Smørgrav
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;
71 	char *freepath;
72 	struct vnode *textvp;
73 	int error;
74 
75 	freepath = NULL;
76 	PROC_LOCK(p);
77 	textvp = p->p_textvp;
78 	vhold(textvp);
79 	PROC_UNLOCK(p);
80 	error = vn_fullpath(td, textvp, &fullpath, &freepath);
81 	vdrop(textvp);
82 	if (error == 0)
83 		sbuf_printf(sb, "%s", fullpath);
84 	if (freepath != NULL)
85 		free(freepath, M_TEMP);
86 	return (error);
87 }
88 
89 /*
90  * Filler function for proc/curproc
91  */
92 int
93 procfs_docurproc(PFS_FILL_ARGS)
94 {
95 	sbuf_printf(sb, "%ld", (long)td->td_proc->p_pid);
96 	return (0);
97 }
98 
99 /*
100  * Adjust mode for some nodes that need it
101  */
102 int
103 procfs_attr(PFS_ATTR_ARGS)
104 {
105 
106 	/* XXX inefficient, split into separate functions */
107 	if (strcmp(pn->pn_name, "note") == 0 ||
108 	    strcmp(pn->pn_name, "notepg") == 0)
109 		vap->va_mode = 0200;
110 	else if (strcmp(pn->pn_name, "mem") == 0 ||
111 	    strcmp(pn->pn_name, "regs") == 0 ||
112 	    strcmp(pn->pn_name, "dbregs") == 0 ||
113 	    strcmp(pn->pn_name, "fpregs") == 0 ||
114 	    strcmp(pn->pn_name, "osrel") == 0)
115 		vap->va_mode = 0600;
116 
117 	if (p != NULL) {
118 		PROC_LOCK_ASSERT(p, MA_OWNED);
119 
120 		if ((p->p_flag & P_SUGID) && pn->pn_type != pfstype_procdir)
121 			vap->va_mode = 0;
122 	}
123 
124 	return (0);
125 }
126 
127 /*
128  * Visibility: some files only exist for non-system processes
129  * Non-static because linprocfs uses it.
130  */
131 int
132 procfs_notsystem(PFS_VIS_ARGS)
133 {
134 	PROC_LOCK_ASSERT(p, MA_OWNED);
135 	return ((p->p_flag & P_SYSTEM) == 0);
136 }
137 
138 /*
139  * Visibility: some files are only visible to process that can debug
140  * the target process.
141  */
142 int
143 procfs_candebug(PFS_VIS_ARGS)
144 {
145 	PROC_LOCK_ASSERT(p, MA_OWNED);
146 	return ((p->p_flag & P_SYSTEM) == 0 && p_candebug(td, p) == 0);
147 }
148 
149 /*
150  * Constructor
151  */
152 static int
153 procfs_init(PFS_INIT_ARGS)
154 {
155 	struct pfs_node *root;
156 	struct pfs_node *dir;
157 	struct pfs_node *node;
158 
159 	root = pi->pi_root;
160 
161 	pfs_create_link(root, "curproc", procfs_docurproc,
162 	    NULL, NULL, NULL, 0);
163 
164 	dir = pfs_create_dir(root, "pid",
165 	    procfs_attr, NULL, NULL, PFS_PROCDEP);
166 	pfs_create_file(dir, "cmdline", procfs_doproccmdline,
167 	    NULL, NULL, NULL, PFS_RD);
168 	pfs_create_file(dir, "dbregs", procfs_doprocdbregs,
169 	    procfs_attr, procfs_candebug, NULL, PFS_RDWR|PFS_RAW);
170 	pfs_create_file(dir, "etype", procfs_doproctype,
171 	    NULL, NULL, NULL, PFS_RD);
172 	pfs_create_file(dir, "fpregs", procfs_doprocfpregs,
173 	    procfs_attr, procfs_candebug, NULL, PFS_RDWR|PFS_RAW);
174 	pfs_create_file(dir, "map", procfs_doprocmap,
175 	    NULL, procfs_notsystem, NULL, PFS_RD);
176 	node = pfs_create_file(dir, "mem", procfs_doprocmem,
177 	    procfs_attr, procfs_candebug, NULL, PFS_RDWR|PFS_RAW);
178 	node->pn_ioctl = procfs_ioctl;
179 	node->pn_close = procfs_close;
180 	pfs_create_file(dir, "note", procfs_doprocnote,
181 	    procfs_attr, procfs_candebug, NULL, PFS_WR);
182 	pfs_create_file(dir, "notepg", procfs_doprocnote,
183 	    procfs_attr, procfs_candebug, NULL, PFS_WR);
184 	pfs_create_file(dir, "regs", procfs_doprocregs,
185 	    procfs_attr, procfs_candebug, NULL, PFS_RDWR|PFS_RAW);
186 	pfs_create_file(dir, "rlimit", procfs_doprocrlimit,
187 	    NULL, NULL, NULL, PFS_RD);
188 	pfs_create_file(dir, "status", procfs_doprocstatus,
189 	    NULL, NULL, NULL, PFS_RD);
190 	pfs_create_file(dir, "osrel", procfs_doosrel,
191 	    procfs_attr, procfs_candebug, NULL, PFS_RDWR);
192 
193 	pfs_create_link(dir, "file", procfs_doprocfile,
194 	    NULL, procfs_notsystem, NULL, 0);
195 
196 	return (0);
197 }
198 
199 /*
200  * Destructor
201  */
202 static int
203 procfs_uninit(PFS_INIT_ARGS)
204 {
205 	/* nothing to do, pseudofs will GC */
206 	return (0);
207 }
208 
209 PSEUDOFS(procfs, 1, PR_ALLOW_MOUNT_PROCFS);
210