2 * Copyright (c) 1993 Jan-Simon Pendry
4 * The Regents of the University of California. All rights reserved.
6 * This code is derived from software contributed to Berkeley by
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
20 * California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * @(#)procfs_ctl.c 8.4 (Berkeley) 6/15/94
40 * $FreeBSD: src/sys/miscfs/procfs/procfs_ctl.c,v 1.20.2.2 2002/01/22 17:22:59 nectar Exp $
41 * $DragonFly: src/sys/vfs/procfs/procfs_ctl.c,v 1.16 2007/03/12 21:08:15 corecode Exp $
44 #include <sys/param.h>
45 #include <sys/systm.h>
48 #include <sys/vnode.h>
49 #include <sys/ptrace.h>
50 #include <sys/signalvar.h>
51 #include <sys/signal2.h>
52 #include <vfs/procfs/procfs.h>
61 * True iff process (p) is in trace wait state
62 * relative to process (curp)
64 #define TRACE_WAIT_P(curp, p) \
65 (((p)->p_stat == SSTOP) && \
66 (p)->p_pptr == (curp) && \
67 ((p)->p_flag & P_TRACED))
69 #define PROCFS_CTL_ATTACH 1
70 #define PROCFS_CTL_DETACH 2
71 #define PROCFS_CTL_STEP 3
72 #define PROCFS_CTL_RUN 4
73 #define PROCFS_CTL_WAIT 5
75 static vfs_namemap_t ctlnames[] = {
76 /* special /proc commands */
77 { "attach", PROCFS_CTL_ATTACH },
78 { "detach", PROCFS_CTL_DETACH },
79 { "step", PROCFS_CTL_STEP },
80 { "run", PROCFS_CTL_RUN },
81 { "wait", PROCFS_CTL_WAIT },
85 static vfs_namemap_t signames[] = {
86 /* regular signal names */
87 { "hup", SIGHUP }, { "int", SIGINT },
88 { "quit", SIGQUIT }, { "ill", SIGILL },
89 { "trap", SIGTRAP }, { "abrt", SIGABRT },
90 { "iot", SIGIOT }, { "emt", SIGEMT },
91 { "fpe", SIGFPE }, { "kill", SIGKILL },
92 { "bus", SIGBUS }, { "segv", SIGSEGV },
93 { "sys", SIGSYS }, { "pipe", SIGPIPE },
94 { "alrm", SIGALRM }, { "term", SIGTERM },
95 { "urg", SIGURG }, { "stop", SIGSTOP },
96 { "tstp", SIGTSTP }, { "cont", SIGCONT },
97 { "chld", SIGCHLD }, { "ttin", SIGTTIN },
98 { "ttou", SIGTTOU }, { "io", SIGIO },
99 { "xcpu", SIGXCPU }, { "xfsz", SIGXFSZ },
100 { "vtalrm", SIGVTALRM }, { "prof", SIGPROF },
101 { "winch", SIGWINCH }, { "info", SIGINFO },
102 { "usr1", SIGUSR1 }, { "usr2", SIGUSR2 },
106 static int procfs_control (struct proc *curp, struct lwp *lp, int op);
109 procfs_control(struct proc *curp, struct lwp *lp, int op)
111 struct proc *p = lp->lwp_proc;
114 ASSERT_LWKT_TOKEN_HELD(&proc_token);
116 /* Can't trace a process that's currently exec'ing. */
117 if ((p->p_flag & P_INEXEC) != 0)
120 * Authorization check: rely on normal debugging protection, except
121 * allow processes to disengage debugging on a process onto which
122 * they have previously attached, but no longer have permission to
125 if (op != PROCFS_CTL_DETACH) {
126 if (securelevel > 0 && p->p_pid == 1)
129 if (!CHECKIO(curp, p) || p_trespass(curp->p_ucred, p->p_ucred))
134 * Attach - attaches the target process for debugging
135 * by the calling process.
137 if (op == PROCFS_CTL_ATTACH) {
138 /* check whether already being traced */
139 if (p->p_flag & P_TRACED)
142 /* can't trace yourself! */
143 if (p->p_pid == curp->p_pid)
147 * Go ahead and set the trace flag.
148 * Save the old parent (it's reset in
149 * _DETACH, and also in kern_exit.c:wait4()
150 * Reparent the process so that the tracing
151 * proc gets to see all the action.
154 p->p_flag |= P_TRACED;
156 p->p_xstat = 0; /* XXX ? */
157 if (p->p_pptr != curp) {
158 p->p_oppid = p->p_pptr->p_pid;
159 proc_reparent(p, curp);
166 * Target process must be stopped, owned by (curp) and
167 * be set up for tracing (P_TRACED flag set).
168 * Allow DETACH to take place at any time for sanity.
169 * Allow WAIT any time, of course.
172 case PROCFS_CTL_DETACH:
173 case PROCFS_CTL_WAIT:
177 if (!TRACE_WAIT_P(curp, p))
184 * do single-step fixup if needed
190 * Don't deliver any signal by default.
191 * To continue with a signal, just send
192 * the signal name to the ctl file
198 * Detach. Cleans up the target process, reparent it if possible
199 * and set it running once more.
201 case PROCFS_CTL_DETACH:
202 /* if not being traced, then this is a painless no-op */
203 if ((p->p_flag & P_TRACED) == 0)
206 /* not being traced any more */
207 p->p_flag &= ~P_TRACED;
209 /* remove pending SIGTRAP, else the process will die */
210 lwp_delsig(lp, SIGTRAP);
212 /* give process back to original parent */
213 if (p->p_oppid != p->p_pptr->p_pid) {
216 pp = pfind(p->p_oppid);
218 proc_reparent(p, pp);
222 p->p_flag &= ~P_WAITED; /* XXX ? */
223 wakeup((caddr_t) curp); /* XXX for CTL_WAIT below ? */
228 * Step. Let the target process execute a single instruction.
230 case PROCFS_CTL_STEP:
232 error = procfs_sstep(lp);
239 * Run. Let the target process continue running until a breakpoint
240 * or some other trap.
246 * Wait for the target process to stop.
247 * If the target is not being traced then just wait
250 case PROCFS_CTL_WAIT:
252 if (p->p_flag & P_TRACED) {
254 p->p_stat != SSTOP &&
255 (p->p_flag & P_TRACED) &&
256 (p->p_pptr == curp)) {
257 error = tsleep((caddr_t) p,
258 PCATCH, "procfsx", 0);
260 if (error == 0 && !TRACE_WAIT_P(curp, p))
263 while (error == 0 && p->p_stat != SSTOP) {
264 error = tsleep((caddr_t) p,
265 PCATCH, "procfs", 0);
271 panic("procfs_control");
275 * If the process is in a stopped state, make it runnable again.
276 * Do not set LWP_BREAKTSLEEP - that is, do not break a tsleep that
277 * might be in progress.
279 if (p->p_stat == SSTOP)
285 procfs_doctl(struct proc *curp, struct lwp *lp, struct pfsnode *pfs,
288 struct proc *p = lp->lwp_proc;
291 char msg[PROCFS_CTLLEN+1];
294 ASSERT_LWKT_TOKEN_HELD(&proc_token);
296 if (uio->uio_rw != UIO_WRITE)
299 xlen = PROCFS_CTLLEN;
300 error = vfs_getuserstr(uio, msg, &xlen);
305 * Map signal names into signal generation
306 * or debug control. Unknown commands and/or signals
309 * Sending a signal while the process is being debugged
310 * also has the side effect of letting the target continue
311 * to run. There is no way to single-step a signal delivery.
315 nm = vfs_findname(ctlnames, msg, xlen);
317 error = procfs_control(curp, lp, nm->nm_val);
319 nm = vfs_findname(signames, msg, xlen);
321 if (TRACE_WAIT_P(curp, p)) {
322 p->p_xstat = nm->nm_val;
327 * Make the process runnable but do not
332 ksignal(p, nm->nm_val);