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
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10 * modification, are permitted provided that the following conditions
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18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
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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 <vfs/procfs/procfs.h>
53 #include <sys/signal2.h>
54 #include <sys/thread2.h>
55 #include <sys/mplock2.h>
56 #include <sys/spinlock2.h>
65 * True iff process (p) is in trace wait state
66 * relative to process (curp)
68 #define TRACE_WAIT_P(curp, p) \
69 (((p)->p_stat == SSTOP) && \
70 (p)->p_pptr == (curp) && \
71 ((p)->p_flag & P_TRACED))
73 #define PROCFS_CTL_ATTACH 1
74 #define PROCFS_CTL_DETACH 2
75 #define PROCFS_CTL_STEP 3
76 #define PROCFS_CTL_RUN 4
77 #define PROCFS_CTL_WAIT 5
79 static vfs_namemap_t ctlnames[] = {
80 /* special /proc commands */
81 { "attach", PROCFS_CTL_ATTACH },
82 { "detach", PROCFS_CTL_DETACH },
83 { "step", PROCFS_CTL_STEP },
84 { "run", PROCFS_CTL_RUN },
85 { "wait", PROCFS_CTL_WAIT },
89 static vfs_namemap_t signames[] = {
90 /* regular signal names */
91 { "hup", SIGHUP }, { "int", SIGINT },
92 { "quit", SIGQUIT }, { "ill", SIGILL },
93 { "trap", SIGTRAP }, { "abrt", SIGABRT },
94 { "iot", SIGIOT }, { "emt", SIGEMT },
95 { "fpe", SIGFPE }, { "kill", SIGKILL },
96 { "bus", SIGBUS }, { "segv", SIGSEGV },
97 { "sys", SIGSYS }, { "pipe", SIGPIPE },
98 { "alrm", SIGALRM }, { "term", SIGTERM },
99 { "urg", SIGURG }, { "stop", SIGSTOP },
100 { "tstp", SIGTSTP }, { "cont", SIGCONT },
101 { "chld", SIGCHLD }, { "ttin", SIGTTIN },
102 { "ttou", SIGTTOU }, { "io", SIGIO },
103 { "xcpu", SIGXCPU }, { "xfsz", SIGXFSZ },
104 { "vtalrm", SIGVTALRM }, { "prof", SIGPROF },
105 { "winch", SIGWINCH }, { "info", SIGINFO },
106 { "usr1", SIGUSR1 }, { "usr2", SIGUSR2 },
110 static int procfs_control (struct proc *curp, struct lwp *lp, int op);
113 procfs_control(struct proc *curp, struct lwp *lp, int op)
115 struct proc *p = lp->lwp_proc;
118 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
119 ASSERT_LWKT_TOKEN_HELD(&proc_token);
121 /* Can't trace a process that's currently exec'ing. */
122 if ((p->p_flag & P_INEXEC) != 0)
125 * Authorization check: rely on normal debugging protection, except
126 * allow processes to disengage debugging on a process onto which
127 * they have previously attached, but no longer have permission to
130 if (op != PROCFS_CTL_DETACH) {
131 if (securelevel > 0 && p->p_pid == 1)
134 if (!CHECKIO(curp, p) || p_trespass(curp->p_ucred, p->p_ucred))
139 * Attach - attaches the target process for debugging
140 * by the calling process.
142 if (op == PROCFS_CTL_ATTACH) {
143 /* check whether already being traced */
144 if (p->p_flag & P_TRACED)
147 /* can't trace yourself! */
148 if (p->p_pid == curp->p_pid)
152 * Go ahead and set the trace flag.
153 * Save the old parent (it's reset in
154 * _DETACH, and also in kern_exit.c:wait4()
155 * Reparent the process so that the tracing
156 * proc gets to see all the action.
159 p->p_flag |= P_TRACED;
161 p->p_xstat = 0; /* XXX ? */
162 if (p->p_pptr != curp) {
163 p->p_oppid = p->p_pptr->p_pid;
164 proc_reparent(p, curp);
171 * Target process must be stopped, owned by (curp) and
172 * be set up for tracing (P_TRACED flag set).
173 * Allow DETACH to take place at any time for sanity.
174 * Allow WAIT any time, of course.
177 case PROCFS_CTL_DETACH:
178 case PROCFS_CTL_WAIT:
182 if (!TRACE_WAIT_P(curp, p))
189 * do single-step fixup if needed
195 * Don't deliver any signal by default.
196 * To continue with a signal, just send
197 * the signal name to the ctl file
203 * Detach. Cleans up the target process, reparent it if possible
204 * and set it running once more.
206 case PROCFS_CTL_DETACH:
207 /* if not being traced, then this is a painless no-op */
208 if ((p->p_flag & P_TRACED) == 0)
211 /* not being traced any more */
212 p->p_flag &= ~P_TRACED;
214 /* remove pending SIGTRAP, else the process will die */
215 spin_lock(&lp->lwp_spin);
216 lwp_delsig(lp, SIGTRAP);
217 spin_unlock(&lp->lwp_spin);
219 /* give process back to original parent */
220 if (p->p_oppid != p->p_pptr->p_pid) {
223 pp = pfind(p->p_oppid);
225 proc_reparent(p, pp);
231 p->p_flag &= ~P_WAITED; /* XXX ? */
232 wakeup((caddr_t) curp); /* XXX for CTL_WAIT below ? */
237 * Step. Let the target process execute a single instruction.
239 case PROCFS_CTL_STEP:
241 error = procfs_sstep(lp);
248 * Run. Let the target process continue running until a breakpoint
249 * or some other trap.
255 * Wait for the target process to stop.
256 * If the target is not being traced then just wait
259 case PROCFS_CTL_WAIT:
261 if (p->p_flag & P_TRACED) {
263 p->p_stat != SSTOP &&
264 (p->p_flag & P_TRACED) &&
265 (p->p_pptr == curp)) {
266 error = tsleep((caddr_t) p,
267 PCATCH, "procfsx", 0);
269 if (error == 0 && !TRACE_WAIT_P(curp, p))
272 while (error == 0 && p->p_stat != SSTOP) {
273 error = tsleep((caddr_t) p,
274 PCATCH, "procfs", 0);
280 panic("procfs_control");
284 * If the process is in a stopped state, make it runnable again.
285 * Do not set LWP_BREAKTSLEEP - that is, do not break a tsleep that
286 * might be in progress.
288 if (p->p_stat == SSTOP)
294 procfs_doctl(struct proc *curp, struct lwp *lp, struct pfsnode *pfs,
297 struct proc *p = lp->lwp_proc;
300 char msg[PROCFS_CTLLEN+1];
303 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
304 ASSERT_LWKT_TOKEN_HELD(&proc_token);
306 if (uio->uio_rw != UIO_WRITE)
309 xlen = PROCFS_CTLLEN;
310 error = vfs_getuserstr(uio, msg, &xlen);
315 * Map signal names into signal generation
316 * or debug control. Unknown commands and/or signals
319 * Sending a signal while the process is being debugged
320 * also has the side effect of letting the target continue
321 * to run. There is no way to single-step a signal delivery.
325 nm = vfs_findname(ctlnames, msg, xlen);
327 error = procfs_control(curp, lp, nm->nm_val);
329 nm = vfs_findname(signames, msg, xlen);
331 if (TRACE_WAIT_P(curp, p)) {
332 p->p_xstat = nm->nm_val;
337 * Make the process runnable but do not
342 ksignal(p, nm->nm_val);