xref: /illumos-gate/usr/src/cmd/ptools/prun/prun.c (revision 1a2d662a91cee3bf82f41cd47c7ae6f3825d9db2)
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 #include <stdio.h>
27 #include <stdlib.h>
28 #include <unistd.h>
29 #include <fcntl.h>
30 #include <string.h>
31 #include <errno.h>
32 #include <sys/types.h>
33 #include <signal.h>
34 #include <libproc.h>
35 
36 static	int	start(char *);
37 static	int	lwpstart(int *, const lwpstatus_t *, const lwpsinfo_t *);
38 
39 static	char	*command;
40 static	const char *lwps;
41 static	struct	ps_prochandle *P;
42 
43 int
44 main(int argc, char **argv)
45 {
46 	int	rc = 0;
47 
48 	if ((command = strrchr(argv[0], '/')) != NULL)
49 		command++;
50 	else
51 		command = argv[0];
52 
53 	if (argc <= 1) {
54 		(void) fprintf(stderr, "usage:\t%s pid[/lwps] ...\n", command);
55 		(void) fprintf(stderr, "  (set stopped processes or lwps "
56 		    "running)\n");
57 		return (2);
58 	}
59 
60 	while (--argc > 0)
61 		rc += start(*++argv);
62 
63 	return (rc);
64 }
65 
66 static int
67 start(char *arg)
68 {
69 	int gcode;
70 	int rc = 0;
71 
72 	if ((P = proc_arg_xgrab(arg, NULL, PR_ARG_PIDS, PGRAB_FORCE |
73 	    PGRAB_RETAIN | PGRAB_NOSTOP, &gcode, &lwps)) == NULL) {
74 		(void) fprintf(stderr, "%s: cannot control %s: %s\n",
75 		    command, arg, Pgrab_error(gcode));
76 		return (1);
77 	}
78 
79 	/*
80 	 * If the victim is stopped because of a job control signal, we
81 	 * need to send it SIGCONT to get it moving again, otherwise
82 	 * the agent will not be able to run, and so will not be able to
83 	 * exit the process.
84 	 */
85 	(void) kill(Pstatus(P)->pr_pid, SIGCONT);
86 
87 	/*
88 	 * if the agent already exists, Pcreate_agent will adopt the
89 	 * extant agent so that we can destroy it
90 	 */
91 	if (Pstatus(P)->pr_lwp.pr_flags & PR_AGENT) {
92 		if (Pcreate_agent(P) != 0) {
93 			(void) fprintf(stderr,
94 			    "%s: cannot remove agent from %s: %s\n",
95 			    command, arg, strerror(errno));
96 
97 			Prelease(P, 0);
98 			return (1);
99 		}
100 
101 		Pdestroy_agent(P);
102 	}
103 
104 	if (lwps != NULL) {
105 		/*
106 		 * The user provided an lwp specification. Let's consider the
107 		 * lwp specification as a mask.  We iterate over all lwps in the
108 		 * process and set running every lwp, which matches the mask.
109 		 * If there is no lwp matching the mask or an error occured
110 		 * during the iteration, set the return code to 1 as indication
111 		 * of an error.  We need to unset run-on-last-close flag,
112 		 * otherwise *all* lwps could be set running after detaching
113 		 * from the process and not only lwps, which were selected.
114 		 */
115 		int lwpcount = 0;
116 
117 		(void) Punsetflags(P, PR_RLC);
118 		(void) Plwp_iter_all(P, (proc_lwp_all_f *)lwpstart, &lwpcount);
119 
120 		if (lwpcount == 0) {
121 			(void) fprintf(stderr, "%s: cannot control %s:"
122 			    " no matching LWPs found\n", command, arg);
123 			rc = 1;
124 		} else if (lwpcount == -1)
125 			rc = 1;
126 	} else {
127 		(void) Psetrun(P, 0, 0);	/* Set the process running. */
128 	}
129 
130 	/*
131 	 * Prelease could change the tracing flags or leave the victim hung
132 	 * so we free the handle by hand.
133 	 */
134 	Pfree(P);
135 	return (rc);
136 }
137 
138 /* ARGSUSED */
139 static int
140 lwpstart(int *lwpcount, const lwpstatus_t *status, const lwpsinfo_t *info)
141 {
142 	struct ps_lwphandle *L;
143 	int gcode;
144 
145 	if (proc_lwp_in_set(lwps, info->pr_lwpid)) {
146 		/*
147 		 * There is a race between the callback from the iterator and
148 		 * grabbing of the lwp.  If the lwp has already exited, Lgrab
149 		 * will return the error code G_NOPROC.  It's not a real error,
150 		 * only if there is no lwp matching the specification.
151 		 */
152 		if ((L = Lgrab(P, info->pr_lwpid, &gcode)) != NULL) {
153 			(void) Lsetrun(L, 0, 0);
154 			Lfree(L);
155 			if (*lwpcount >= 0)
156 				(*lwpcount)++;
157 		} else if (gcode != G_NOPROC) {
158 			(void) fprintf(stderr, "%s: cannot control %d/%d: %s\n",
159 			    command, (int)Pstatus(P)->pr_pid,
160 			    (int)info->pr_lwpid, Lgrab_error(gcode));
161 			*lwpcount = -1;
162 		}
163 	}
164 	return (0);
165 }
166