usr/src/cmd/ptools/prun/prun.c

   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
  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
  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
 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 }