xref: /titanic_50/usr/src/cmd/ptools/prun/prun.c (revision b06cdb87d254343cca2e66a21fd421617c3a0b7b)
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 
38 static	int	start(char *);
39 static	int	lwpstart(int *, const lwpstatus_t *, const lwpsinfo_t *);
40 
41 static	char	*command;
42 static	const char *lwps;
43 static	struct	ps_prochandle *P;
44 
45 int
main(int argc,char ** argv)46 main(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 
68 static int
start(char * arg)69 start(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 */
141 static int
lwpstart(int * lwpcount,const lwpstatus_t * status,const lwpsinfo_t * info)142 lwpstart(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