1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#pragma ident	"%Z%%M%	%I%	%E% SMI"
27
28#include <stdio.h>
29#include <stdlib.h>
30#include <unistd.h>
31#include <fcntl.h>
32#include <string.h>
33#include <errno.h>
34#include <sys/types.h>
35#include <signal.h>
36#include <libproc.h>
37
38static	int	start(char *);
39static	int	lwpstart(int *, const lwpstatus_t *, const lwpsinfo_t *);
40
41static	char	*command;
42static	const char *lwps;
43static	struct	ps_prochandle *P;
44
45int
46main(int argc, char **argv)
47{
48	int	rc = 0;
49
50	if ((command = strrchr(argv[0], '/')) != NULL)
51		command++;
52	else
53		command = argv[0];
54
55	if (argc <= 1) {
56		(void) fprintf(stderr, "usage:\t%s pid[/lwps] ...\n", command);
57		(void) fprintf(stderr, "  (set stopped processes or lwps "
58		    "running)\n");
59		return (2);
60	}
61
62	while (--argc > 0)
63		rc += start(*++argv);
64
65	return (rc);
66}
67
68static int
69start(char *arg)
70{
71	int gcode;
72	int rc = 0;
73
74	if ((P = proc_arg_xgrab(arg, NULL, PR_ARG_PIDS, PGRAB_FORCE |
75	    PGRAB_RETAIN | PGRAB_NOSTOP, &gcode, &lwps)) == NULL) {
76		(void) fprintf(stderr, "%s: cannot control %s: %s\n",
77		    command, arg, Pgrab_error(gcode));
78		return (1);
79	}
80
81	/*
82	 * If the victim is stopped because of a job control signal, we
83	 * need to send it SIGCONT to get it moving again, otherwise
84	 * the agent will not be able to run, and so will not be able to
85	 * exit the process.
86	 */
87	(void) kill(Pstatus(P)->pr_pid, SIGCONT);
88
89	/*
90	 * if the agent already exists, Pcreate_agent will adopt the
91	 * extant agent so that we can destroy it
92	 */
93	if (Pstatus(P)->pr_lwp.pr_flags & PR_AGENT) {
94		if (Pcreate_agent(P) != 0) {
95			(void) fprintf(stderr,
96			    "%s: cannot remove agent from %s: %s\n",
97			    command, arg, strerror(errno));
98
99			Prelease(P, 0);
100			return (1);
101		}
102
103		Pdestroy_agent(P);
104	}
105
106	if (lwps != NULL) {
107		/*
108		 * The user provided an lwp specification. Let's consider the
109		 * lwp specification as a mask.  We iterate over all lwps in the
110		 * process and set running every lwp, which matches the mask.
111		 * If there is no lwp matching the mask or an error occured
112		 * during the iteration, set the return code to 1 as indication
113		 * of an error.  We need to unset run-on-last-close flag,
114		 * otherwise *all* lwps could be set running after detaching
115		 * from the process and not only lwps, which were selected.
116		 */
117		int lwpcount = 0;
118
119		(void) Punsetflags(P, PR_RLC);
120		(void) Plwp_iter_all(P, (proc_lwp_all_f *)lwpstart, &lwpcount);
121
122		if (lwpcount == 0) {
123			(void) fprintf(stderr, "%s: cannot control %s:"
124			    " no matching LWPs found\n", command, arg);
125			rc = 1;
126		} else if (lwpcount == -1)
127			rc = 1;
128	} else {
129		(void) Psetrun(P, 0, 0);	/* Set the process running. */
130	}
131
132	/*
133	 * Prelease could change the tracing flags or leave the victim hung
134	 * so we free the handle by hand.
135	 */
136	Pfree(P);
137	return (rc);
138}
139
140/* ARGSUSED */
141static int
142lwpstart(int *lwpcount, const lwpstatus_t *status, const lwpsinfo_t *info)
143{
144	struct ps_lwphandle *L;
145	int gcode;
146
147	if (proc_lwp_in_set(lwps, info->pr_lwpid)) {
148		/*
149		 * There is a race between the callback from the iterator and
150		 * grabbing of the lwp.  If the lwp has already exited, Lgrab
151		 * will return the error code G_NOPROC.  It's not a real error,
152		 * only if there is no lwp matching the specification.
153		 */
154		if ((L = Lgrab(P, info->pr_lwpid, &gcode)) != NULL) {
155			(void) Lsetrun(L, 0, 0);
156			Lfree(L);
157			if (*lwpcount >= 0)
158				(*lwpcount)++;
159		} else if (gcode != G_NOPROC) {
160			(void) fprintf(stderr, "%s: cannot control %d/%d: %s\n",
161			    command, (int)Pstatus(P)->pr_pid,
162			    (int)info->pr_lwpid, Lgrab_error(gcode));
163			*lwpcount = -1;
164		}
165	}
166	return (0);
167}
168