xref: /freebsd/sys/fs/procfs/procfs.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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 	struct vnode *textvp;
73 	int err;
74 
75 	textvp = p->p_textvp;
76 	VI_LOCK(textvp);
77 	vholdl(textvp);
78 	err = vn_lock(textvp, LK_EXCLUSIVE | LK_INTERLOCK);
79 	vdrop(textvp);
80 	if (err)
81 		return (err);
82 	vn_fullpath(td, textvp, &fullpath, &freepath);
83 	VOP_UNLOCK(textvp, 0);
84 	sbuf_printf(sb, "%s", fullpath);
85 	if (freepath)
86 		free(freepath, M_TEMP);
87 	return (0);
88 }
89 
90 /*
91  * Filler function for proc/curproc
92  */
93 int
94 procfs_docurproc(PFS_FILL_ARGS)
95 {
96 	sbuf_printf(sb, "%ld", (long)td->td_proc->p_pid);
97 	return (0);
98 }
99 
100 /*
101  * Adjust mode for some nodes that need it
102  */
103 int
104 procfs_attr(PFS_ATTR_ARGS)
105 {
106 	PROC_LOCK_ASSERT(p, MA_OWNED);
107 
108 	/* XXX inefficient, split into separate functions */
109 	if (strcmp(pn->pn_name, "ctl") == 0 ||
110 	    strcmp(pn->pn_name, "note") == 0 ||
111 	    strcmp(pn->pn_name, "notepg") == 0)
112 		vap->va_mode = 0200;
113 	else if (strcmp(pn->pn_name, "mem") == 0 ||
114 	    strcmp(pn->pn_name, "regs") == 0 ||
115 	    strcmp(pn->pn_name, "dbregs") == 0 ||
116 	    strcmp(pn->pn_name, "fpregs") == 0)
117 		vap->va_mode = 0600;
118 
119 	if ((p->p_flag & P_SUGID) && pn->pn_type != pfstype_procdir)
120 		vap->va_mode = 0;
121 
122 	vap->va_uid = p->p_ucred->cr_uid;
123 	vap->va_gid = p->p_ucred->cr_gid;
124 
125 	return (0);
126 }
127 
128 /*
129  * Visibility: some files only exist for non-system processes
130  * Non-static because linprocfs uses it.
131  */
132 int
133 procfs_notsystem(PFS_VIS_ARGS)
134 {
135 	PROC_LOCK_ASSERT(p, MA_OWNED);
136 	return ((p->p_flag & P_SYSTEM) == 0);
137 }
138 
139 /*
140  * Visibility: some files are only visible to process that can debug
141  * the target process.
142  */
143 int
144 procfs_candebug(PFS_VIS_ARGS)
145 {
146 	PROC_LOCK_ASSERT(p, MA_OWNED);
147 	return ((p->p_flag & P_SYSTEM) == 0 && p_candebug(td, p) == 0);
148 }
149 
150 /*
151  * Constructor
152  */
153 static int
154 procfs_init(PFS_INIT_ARGS)
155 {
156 	struct pfs_node *root;
157 	struct pfs_node *dir;
158 	struct pfs_node *node;
159 
160 	root = pi->pi_root;
161 
162 	pfs_create_link(root, "curproc", procfs_docurproc,
163 	    NULL, NULL, NULL, 0);
164 
165 	dir = pfs_create_dir(root, "pid",
166 	    procfs_attr, NULL, NULL, PFS_PROCDEP);
167 	pfs_create_file(dir, "cmdline", procfs_doproccmdline,
168 	    NULL, NULL, NULL, PFS_RD);
169 	pfs_create_file(dir, "ctl", procfs_doprocctl,
170 	    procfs_attr, NULL, NULL, PFS_WR);
171 	pfs_create_file(dir, "dbregs", procfs_doprocdbregs,
172 	    procfs_attr, procfs_candebug, NULL, PFS_RDWR|PFS_RAW);
173 	pfs_create_file(dir, "etype", procfs_doproctype,
174 	    NULL, NULL, NULL, PFS_RD);
175 	pfs_create_file(dir, "fpregs", procfs_doprocfpregs,
176 	    procfs_attr, procfs_candebug, NULL, PFS_RDWR|PFS_RAW);
177 	pfs_create_file(dir, "map", procfs_doprocmap,
178 	    NULL, procfs_notsystem, NULL, PFS_RD);
179 	node = pfs_create_file(dir, "mem", procfs_doprocmem,
180 	    procfs_attr, procfs_candebug, NULL, PFS_RDWR|PFS_RAW);
181 	node->pn_ioctl = procfs_ioctl;
182 	node->pn_close = procfs_close;
183 	pfs_create_file(dir, "note", procfs_doprocnote,
184 	    procfs_attr, procfs_candebug, NULL, PFS_WR);
185 	pfs_create_file(dir, "notepg", procfs_doprocnote,
186 	    procfs_attr, procfs_candebug, NULL, PFS_WR);
187 	pfs_create_file(dir, "regs", procfs_doprocregs,
188 	    procfs_attr, procfs_candebug, NULL, PFS_RDWR|PFS_RAW);
189 	pfs_create_file(dir, "rlimit", procfs_doprocrlimit,
190 	    NULL, NULL, NULL, PFS_RD);
191 	pfs_create_file(dir, "status", procfs_doprocstatus,
192 	    NULL, NULL, NULL, PFS_RD);
193 
194 	pfs_create_link(dir, "file", procfs_doprocfile,
195 	    NULL, procfs_notsystem, NULL, 0);
196 
197 	return (0);
198 }
199 
200 /*
201  * Destructor
202  */
203 static int
204 procfs_uninit(PFS_INIT_ARGS)
205 {
206 	/* nothing to do, pseudofs will GC */
207 	return (0);
208 }
209 
210 PSEUDOFS(procfs, 1);
211