usr/src/cmd/ptools/preap/preap.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, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <unistd.h>
  32 #include <fcntl.h>
  33 #include <ctype.h>
  34 #include <string.h>
  35 #include <signal.h>
  36 #include <errno.h>
  37 #include <sys/types.h>
  38 #include <sys/wait.h>
  39 #include <libproc.h>
  40
  41 #define NOREAP_TIME 60          /* wait 60 seconds before allow a reap */
  42
  43 static volatile int interrupt;
  44 static int Fflag;
  45 static char *command;
  46
  47 static void
  48 intr(int sig)
  49 {
  50         interrupt = sig;
  51 }
  52
  53 static int
  54 open_usage(pid_t pid, int *perr)
  55 {
  56         char path[64];
  57         struct stat64 st;
  58         int fd;
  59
  60         (void) snprintf(path, sizeof (path), "/proc/%d/usage", (int)pid);
  61
  62         /*
  63          * Attempt to open the usage file, and return the fd if we can
  64          * confirm this is a regular file provided by /proc.
  65          */
  66         if ((fd = open64(path, O_RDONLY)) >= 0) {
  67                 if (fstat64(fd, &st) != 0 || !S_ISREG(st.st_mode) ||
  68                     strcmp(st.st_fstype, "proc") != 0) {
  69                         (void) close(fd);
  70                         fd = -1;
  71                 }
  72         } else if (errno == EACCES || errno == EPERM)
  73                 *perr = G_PERM;
  74
  75         return (fd);
  76 }
  77
  78 static int
  79 proc_usage(pid_t pid, prusage_t *pup, int *perr)
  80 {
  81         int fd;
  82
  83         *perr = G_NOPROC;
  84
  85         if ((fd = open_usage(pid, perr)) != -1) {
  86                 if (read(fd, pup, sizeof (prusage_t)) == sizeof (prusage_t)) {
  87                         *perr = 0;
  88                         (void) close(fd);
  89                         return (0);
  90                 }
  91
  92                 /*
  93                  * If the read failed, the process may have gone away.
  94                  */
  95                 (void) close(fd);
  96         }
  97         return (-1);
  98 }
  99
 100 /*
 101  * Force the parent process (ppid) to wait for its child process (pid).
 102  */
 103 static int
 104 reap(char *arg, pid_t *reap_pid, int *exit_status)
 105 {
 106         struct ps_prochandle *Pr;
 107         siginfo_t siginfo;
 108         psinfo_t psinfo;
 109         prusage_t usage;
 110         pid_t pid, ppid;
 111         time_t elapsed;
 112         int gret;
 113
 114         /*
 115          * get the specified pid and the psinfo struct
 116          */
 117         if ((pid = proc_arg_psinfo(arg, PR_ARG_PIDS, &psinfo, &gret)) == -1) {
 118                 (void) fprintf(stderr, "%s: cannot examine %s: %s\n",
 119                     command, arg, Pgrab_error(gret));
 120                 return (1);
 121         }
 122
 123         if (psinfo.pr_nlwp != 0) {
 124                 (void) fprintf(stderr, "%s: process not defunct: %d\n",
 125                     command, (int)pid);
 126                 return (1);
 127         }
 128
 129         *exit_status = psinfo.pr_wstat;
 130         *reap_pid = psinfo.pr_pid;
 131         ppid = psinfo.pr_ppid;
 132
 133         if (ppid == 1) {
 134                 (void) fprintf(stderr, "%s: Failed to reap %d: the only "
 135                     "non-defunct ancestor is 'init'\n", command,
 136                     (int)pid);
 137                 return (1);
 138         }
 139
 140         if (proc_usage(pid, &usage, &gret) == 0) {
 141                 elapsed = usage.pr_tstamp.tv_sec - usage.pr_term.tv_sec;
 142         } else {
 143                 (void) fprintf(stderr, "%s: cannot examine %d: %s\n",
 144                     command, (int)pid, Pgrab_error(gret));
 145                 return (1);
 146         }
 147
 148         if ((Fflag == 0) && (elapsed < NOREAP_TIME)) {
 149                 (void) fprintf(stderr, "%s: unsafe to reap %d; it has been "
 150                     "defunct less than %d seconds\n", command, (int)pid,
 151                     NOREAP_TIME);
 152                 return (1);
 153         }
 154
 155         if ((Pr = Pgrab(ppid, Fflag | PGRAB_NOSTOP, &gret)) == NULL) {
 156                 (void) fprintf(stderr, "%s: cannot examine %d: %s\n", command,
 157                     (int)ppid, Pgrab_error(gret));
 158                 return (1);
 159         }
 160
 161         if ((Fflag == 0) && (Pstate(Pr) == PS_STOP)) {
 162                 Prelease(Pr, 0);
 163                 (void) fprintf(stderr, "%s: unsafe to reap %d; parent is "
 164                     "stopped and may reap status upon restart\n", command,
 165                     (int)pid);
 166                 return (1);
 167         }
 168
 169         /*
 170          * Pstop() will fail if the process to be stopped has become a zombie.
 171          * This means that we can say with certainty that the child of this
 172          * process has not changed parents (i.e. been reparented to init) once
 173          * the Pstop() succeeds.
 174          */
 175         if (Pstop(Pr, 1000) != 0) {
 176                 Prelease(Pr, 0);
 177                 (void) fprintf(stderr, "%s: failed to stop %d: %s", command,
 178                     (int)ppid, strerror(errno));
 179                 return (1);
 180         }
 181
 182         if (pr_waitid(Pr, P_PID, pid, &siginfo, WEXITED|WNOHANG) != 0) {
 183                 Prelease(Pr, 0);
 184                 (void) fprintf(stderr, "%s: waitid() in process %d failed: %s",
 185                     command, (int)ppid, strerror(errno));
 186                 return (1);
 187         }
 188
 189         Prelease(Pr, 0);
 190         return (0);
 191 }
 192
 193 static void
 194 print_exit_status(pid_t pid, int wstat)
 195 {
 196         (void) printf("%d: ", (int)pid);
 197         if (WIFSIGNALED(wstat)) {
 198                 char buf[SIG2STR_MAX];
 199                 int sig = WTERMSIG(wstat);
 200
 201                 if (sig2str(sig, buf) == 0)
 202                         (void) printf("killed by signal %s", buf);
 203                 else
 204                         (void) printf("killed by signal %d", sig);
 205
 206                 if (WCOREDUMP(wstat))
 207                         (void) printf(" (core dumped)");
 208         } else {
 209                 (void) printf("exited with status %d", WEXITSTATUS(wstat));
 210         }
 211         (void) printf("\n");
 212 }
 213
 214 int
 215 main(int argc, char *argv[])
 216 {
 217         int retc = 0;
 218         int opt;
 219         int errflg = 0;
 220
 221         if ((command = strrchr(argv[0], '/')) != NULL)
 222                 command++;
 223         else
 224                 command = argv[0];
 225
 226         while ((opt = getopt(argc, argv, "F")) != EOF) {
 227                 switch (opt) {
 228                 case 'F':               /* force grabbing (no O_EXCL) */
 229                         Fflag = PGRAB_FORCE;
 230                         break;
 231                 default:
 232                         errflg = 1;
 233                         break;
 234                 }
 235         }
 236
 237         argc -= optind;
 238         argv += optind;
 239
 240         if (errflg || argc <= 0) {
 241                 (void) fprintf(stderr, "usage:  %s pid ...\n", command);
 242                 (void) fprintf(stderr, "  (Reap a defunct process by forcing "
 243                     "its parent to wait(2) for it)\n");
 244                 exit(2);
 245         }
 246
 247         /* catch signals from terminal */
 248         if (sigset(SIGHUP, SIG_IGN) == SIG_DFL)
 249                 (void) sigset(SIGHUP, intr);
 250         if (sigset(SIGINT, SIG_IGN) == SIG_DFL)
 251                 (void) sigset(SIGINT, intr);
 252         if (sigset(SIGPIPE, SIG_IGN) == SIG_DFL)
 253                 (void) sigset(SIGPIPE, intr);
 254         if (sigset(SIGQUIT, SIG_IGN) == SIG_DFL)
 255                 (void) sigset(SIGQUIT, intr);
 256         (void) sigset(SIGTERM, intr);
 257
 258         while (--argc >= 0 && !interrupt) {
 259                 pid_t pid;
 260                 int wstat, r;
 261
 262                 retc += r = reap(*argv++, &pid, &wstat);
 263
 264                 if (r == 0)
 265                         print_exit_status(pid, wstat);
 266         }
 267
 268         if (interrupt && retc == 0)
 269                 retc++;
 270         return (retc == 0 ? 0 : 1);
 271 }