* 2007-07-10 Jan Kratochvil <jan.kratochvil@redhat.com>
*/
+/* For getpgid(2). */
#define _GNU_SOURCE 1
#include <stdio.h>
#include <assert.h>
#include <pty.h>
#include <poll.h>
+#include <sys/stat.h>
+
+#define LENGTH(x) (sizeof (x) / sizeof (*(x)))
static const char *progname;
-static volatile int signal_child_hit = 0;
+static volatile pid_t child;
+
+static void signal_chld (int signo)
+{
+}
+
+static volatile int signal_alrm_hit = 0;
-static void signal_child (int signo)
+static void signal_alrm (int signo)
{
- signal_child_hit = 1;
+ signal_alrm_hit = 1;
}
static char childptyname[LINE_MAX];
-static pid_t child;
-static int spawn (char **argv)
+static void print_child_error (const char *reason, char **argv)
+{
+ char **sp;
+
+ fprintf (stderr, "%s: %d %s:", progname, (int) child, reason);
+ for (sp = argv; *sp != NULL; sp++)
+ {
+ fputc (' ', stderr);
+ fputs (*sp, stderr);
+ }
+ fputc ('\n', stderr);
+}
+
+static int read_out (int amaster)
+{
+ char buf[LINE_MAX];
+ ssize_t buf_got;
+
+ buf_got = read (amaster, buf, sizeof buf);
+ if (buf_got == 0)
+ return 0;
+ /* Weird but at least after POLLHUP we get EIO instead of just EOF. */
+ if (buf_got == -1 && errno == EIO)
+ return 0;
+ if (buf_got == -1 && errno == EAGAIN)
+ return 0;
+ if (buf_got < 0)
+ {
+ perror ("read (amaster)");
+ exit (EXIT_FAILURE);
+ }
+ if (write (STDOUT_FILENO, buf, buf_got) != buf_got)
+ {
+ perror ("write(2)");
+ exit (EXIT_FAILURE);
+ }
+ return 1;
+}
+
+/* kill (child, 0) ==0 sometimes even when CHILD's state is already Z. */
+
+static int child_exited (void)
+{
+ char buf[200];
+ int fd, i, retval;
+ ssize_t got;
+ char *state;
+
+ snprintf (buf, sizeof (buf), "/proc/%ld/stat", (long) child);
+ fd = open (buf, O_RDONLY);
+ if (fd == -1)
+ {
+ perror ("open (/proc/CHILD/stat)");
+ exit (EXIT_FAILURE);
+ }
+ got = read (fd, buf, sizeof(buf));
+ if (got <= 0)
+ {
+ perror ("read (/proc/CHILD/stat)");
+ exit (EXIT_FAILURE);
+ }
+ if (close (fd) != 0)
+ {
+ perror ("close (/proc/CHILD/stat)");
+ exit (EXIT_FAILURE);
+ }
+ i = sscanf (buf, "%*d%*s%ms", &state);
+ if (i != 1)
+ {
+ perror ("sscanf (/proc/CHILD/stat)");
+ exit (EXIT_FAILURE);
+ }
+ retval = strcmp (state, "Z") == 0;
+ free (state);
+ return retval;
+}
+
+static int spawn (char **argv, int timeout)
{
pid_t child_got;
- int status, amaster, i;
+ int status, amaster, i, rc;
struct sigaction act;
- sigset_t sigset;
+ sigset_t set;
+ struct termios termios;
+ unsigned alarm_orig;
- /* Never miss SIGCHLD. */
- i = sigemptyset (&sigset);
- assert (i == 0);
- i = sigaddset (&sigset, SIGCHLD);
- assert (i == 0);
- i = sigprocmask (SIG_BLOCK, &sigset, NULL);
- assert (i == 0);
- i = sigemptyset (&sigset);
- assert (i == 0);
-
- /* We do not use signal(2) to be sure we have SA_RESTART unset. */
+ /* We do not use signal(2) to be sure we do not have SA_RESTART. */
memset (&act, 0, sizeof (act));
- act.sa_handler = signal_child;
+ act.sa_handler = signal_chld;
i = sigemptyset (&act.sa_mask);
assert (i == 0);
- act.sa_flags = 0;
+ act.sa_flags = 0; /* !SA_RESTART */
i = sigaction (SIGCHLD, &act, NULL);
assert (i == 0);
- child = forkpty (&amaster, childptyname, NULL, NULL);
+ i = sigemptyset (&set);
+ assert (i == 0);
+ i = sigaddset (&set, SIGCHLD);
+ assert (i == 0);
+ i = sigprocmask (SIG_SETMASK, &set, NULL);
+ assert (i == 0);
+
+ /* With TERMP passed as NULL we get "\n" -> "\r\n". */
+ termios.c_iflag = IGNBRK | IGNPAR;
+ termios.c_oflag = 0;
+ termios.c_cflag = CS8 | CREAD | CLOCAL | HUPCL | B9600;
+ termios.c_lflag = IEXTEN | NOFLSH;
+ memset (termios.c_cc, _POSIX_VDISABLE, sizeof (termios.c_cc));
+ termios.c_cc[VTIME] = 0;
+ termios.c_cc[VMIN ] = 1;
+ cfmakeraw (&termios);
+#ifdef FLUSHO
+ /* Workaround a readline deadlock bug in _get_tty_settings(). */
+ termios.c_lflag &= ~FLUSHO;
+#endif
+ child = forkpty (&amaster, childptyname, &termios, NULL);
switch (child)
{
case -1:
perror ("forkpty(3)");
exit (EXIT_FAILURE);
case 0:
+ /* Do not replace STDIN as inferiors query its termios. */
+#if 0
+ i = close (STDIN_FILENO);
+ assert (i == 0);
+ i = open ("/dev/null", O_RDONLY);
+ assert (i == STDIN_FILENO);
+#endif
+
+ i = sigemptyset (&set);
+ assert (i == 0);
+ i = sigprocmask (SIG_SETMASK, &set, NULL);
+ assert (i == 0);
+
/* Do not setpgrp(2) in the parent process as the process-group
is shared for the whole sh(1) pipeline we could be a part
of. The process-group is set according to PID of the first
perror ("getpgrp(2)");
exit (EXIT_FAILURE);
}
- execvp (argv[1], argv + 1);
+ execvp (argv[0], argv);
perror ("execvp(2)");
exit (EXIT_FAILURE);
default:
perror ("fcntl (amaster, F_SETFL, O_NONBLOCK)");
exit (EXIT_FAILURE);
}
- for (;;)
+
+ /* We do not use signal(2) to be sure we do not have SA_RESTART. */
+ act.sa_handler = signal_alrm;
+ i = sigaction (SIGALRM, &act, NULL);
+ assert (i == 0);
+
+ alarm_orig = alarm (timeout);
+ assert (alarm_orig == 0);
+
+ i = sigemptyset (&set);
+ assert (i == 0);
+
+ while (!signal_alrm_hit)
{
struct pollfd pollfd;
- char buf[LINE_MAX];
- ssize_t buf_got;
pollfd.fd = amaster;
pollfd.events = POLLIN;
- i = ppoll (&pollfd, 1, NULL, &sigset);
- assert (i == -1 || i == 1);
- if (i == -1)
- {
- assert (errno == EINTR && signal_child_hit != 0);
- break;
+ i = ppoll (&pollfd, 1, NULL, &set);
+ if (i == -1 && errno == EINTR)
+ {
+ if (child_exited ())
+ break;
+ /* Non-CHILD child may have exited. */
+ continue;
+ }
+ assert (i == 1);
+ /* Data available? Process it first. */
+ if (pollfd.revents & POLLIN)
+ {
+ if (!read_out (amaster))
+ {
+ fprintf (stderr, "%s: Unexpected EOF\n", progname);
+ exit (EXIT_FAILURE);
+ }
}
- /* i == 1 */
- assert (pollfd.revents != 0);
if (pollfd.revents & POLLHUP)
break;
- if (pollfd.revents != POLLIN)
- {
+ if ((pollfd.revents &= ~POLLIN) != 0)
+ {
fprintf (stderr, "%s: ppoll(2): revents 0x%x\n", progname,
(unsigned) pollfd.revents);
exit (EXIT_FAILURE);
}
- buf_got = read (amaster, buf, sizeof buf);
- if (buf_got == 0)
+ /* Child exited? */
+ if (child_exited ())
break;
- if (buf_got == -1)
- {
- perror ("read (amaster)");
- exit (EXIT_FAILURE);
- }
- if (write (STDOUT_FILENO, buf, buf_got) != buf_got)
- {
- perror ("write(2)");
- exit (EXIT_FAILURE);
- }
}
+
+ if (signal_alrm_hit)
+ {
+ i = kill (child, SIGKILL);
+ assert (i == 0);
+ }
+ else
+ alarm (0);
+
/* WNOHANG still could fail. */
child_got = waitpid (child, &status, 0);
if (child != child_got)
fprintf (stderr, "waitpid (%d) = %d: %m\n", (int) child, (int) child_got);
exit (EXIT_FAILURE);
}
- if (!WIFEXITED (status))
+ if (signal_alrm_hit)
+ {
+ char *buf;
+
+ if (asprintf (&buf, "Timed out after %d seconds", timeout) != -1)
+ {
+ print_child_error (buf, argv);
+ free (buf);
+ }
+ rc = 128 + SIGALRM;
+ }
+ else if (WIFEXITED (status))
+ rc = WEXITSTATUS (status);
+ else if (WIFSIGNALED (status))
+ {
+ print_child_error (strsignal (WTERMSIG (status)), argv);
+ rc = 128 + WTERMSIG (status);
+ }
+ else if (WIFSTOPPED (status))
+ {
+ fprintf (stderr, "waitpid (%d): WIFSTOPPED - WSTOPSIG is %d\n",
+ (int) child, WSTOPSIG (status));
+ exit (EXIT_FAILURE);
+ }
+ else
{
fprintf (stderr, "waitpid (%d): !WIFEXITED (%d)\n", (int) child, status);
exit (EXIT_FAILURE);
}
+
+ /* Not used in fact. */
+ i = sigprocmask (SIG_SETMASK, &set, NULL);
+ assert (i == 0);
+
+ /* Do not unset O_NONBLOCK as a stale child (the whole purpose of this
+ program) having open its output pty would block us in read_out. */
+#if 0
+ i = fcntl (amaster, F_SETFL, O_RDONLY /* !O_NONBLOCK */);
+ if (i != 0)
+ {
+ perror ("fcntl (amaster, F_SETFL, O_RDONLY /* !O_NONBLOCK */)");
+ exit (EXIT_FAILURE);
+ }
+#endif
+
+ while (read_out (amaster));
+
/* Do not close the master FD as the child would have `/dev/pts/23 (deleted)'
entries which are not expected (and expecting ` (deleted)' would be
a race. */
}
#endif
- return WEXITSTATUS (status);
+ return rc;
}
/* Detected commandline may look weird due to a race:
return cmdline;
}
-static int fd_fs_scan (pid_t pid, int (*func) (pid_t pid, const char *link))
+static int dir_scan (const char *dirname,
+ int (*callback) (struct dirent *dirent, const char *pathname))
{
DIR *dir;
struct dirent *dirent;
- char dirname[64];
int rc = 0;
- if (snprintf (dirname, sizeof dirname, "/proc/%d/fd", (int) pid) < 0)
- {
- perror ("snprintf(3)");
- exit (EXIT_FAILURE);
- }
dir = opendir (dirname);
if (dir == NULL)
{
if (errno == EACCES || errno == ENOENT)
- return 0;
+ return rc;
fprintf (stderr, "%s: opendir (\"%s\"): %m\n", progname, dirname);
exit (EXIT_FAILURE);
}
while ((errno = 0, dirent = readdir (dir)))
{
- char linkname[LINE_MAX], buf[LINE_MAX];
- int linkname_len;
- ssize_t buf_len;
+ char pathname[LINE_MAX];
+ int pathname_len;
- /* FIXME: POSIX portability. */
- if ((dirent->d_type != DT_DIR && dirent->d_type != DT_LNK)
- || (dirent->d_type == DT_DIR && strcmp (dirent->d_name, ".") != 0
- && strcmp (dirent->d_name, "..") != 0)
- || (dirent->d_type == DT_LNK && strspn (dirent->d_name, "0123456789")
- != strlen (dirent->d_name)))
- {
- /* There is a race, D_TYPE may be uninitialized if stat(2) fails. */
- if (dirent->d_type != DT_UNKNOWN)
- fprintf (stderr, "Unexpected entry \"%s\" (d_type %u)"
- " on readdir (\"%s\"): %m\n",
- dirent->d_name, (unsigned) dirent->d_type, dirname);
- continue;
- }
- if (dirent->d_type == DT_DIR)
- continue;
- linkname_len = snprintf (linkname, sizeof linkname, "%s/%s", dirname,
- dirent->d_name);
- if (linkname_len <= 0 || linkname_len >= sizeof linkname)
+ pathname_len = snprintf (pathname, sizeof pathname, "%s/%s",
+ dirname, dirent->d_name);
+ if (pathname_len <= 0 || pathname_len >= (int) sizeof pathname)
{
- fprintf (stderr, "Link content too long: `%s' / `%s'\n",
- dirent->d_name, dirent->d_name);
+ fprintf (stderr, "entry file name too long: `%s' / `%s'\n",
+ dirname, dirent->d_name);
continue;
}
- buf_len = readlink (linkname, buf, sizeof buf - 1);
- if (buf_len <= 0 || buf_len >= sizeof buf - 1)
- {
- if (errno != ENOENT && errno != EACCES)
- fprintf (stderr, "Error reading link \"%s\": %m\n",
- linkname);
- continue;
+ /* RHEL-4.5 on s390x never fills in D_TYPE. */
+ if (dirent->d_type == DT_UNKNOWN)
+ {
+ struct stat statbuf;
+ int i;
+
+ /* We are not interested in the /proc/PID/fd/ links targets. */
+ i = lstat (pathname, &statbuf);
+ if (i == -1)
+ {
+ if (errno == EACCES || errno == ENOENT)
+ continue;
+ fprintf (stderr, "%s: stat (\"%s\"): %m\n", progname, pathname);
+ exit (EXIT_FAILURE);
+ }
+ if (S_ISDIR (statbuf.st_mode))
+ dirent->d_type = DT_DIR;
+ if (S_ISLNK (statbuf.st_mode))
+ dirent->d_type = DT_LNK;
+ /* No other D_TYPE types used in this code. */
}
- buf[buf_len] = 0;
- rc = (*func) (pid, buf);
+ rc = (*callback) (dirent, pathname);
if (rc != 0)
{
errno = 0;
return rc;
}
-static void pid_fs_scan (void (*func) (pid_t pid, void *data), void *data)
+static int fd_fs_scan (pid_t pid, int (*func) (pid_t pid, const char *link))
{
- DIR *dir;
- struct dirent *dirent;
+ char dirname[64];
- dir = opendir ("/proc");
- if (dir == NULL)
- {
- perror ("opendir (\"/proc\")");
- exit (EXIT_FAILURE);
- }
- while ((errno = 0, dirent = readdir (dir)))
- {
- /* FIXME: POSIX portability. */
- if (dirent->d_type != DT_DIR
- || strspn (dirent->d_name, "0123456789") != strlen (dirent->d_name))
- continue;
- (*func) (atoi (dirent->d_name), data);
- }
- if (errno != 0)
- {
- perror ("readdir (\"/proc\")");
- exit (EXIT_FAILURE);
- }
- if (closedir (dir) != 0)
+ if (snprintf (dirname, sizeof dirname, "/proc/%d/fd", (int) pid) < 0)
{
- perror ("closedir (\"/proc\")");
+ perror ("snprintf(3)");
exit (EXIT_FAILURE);
}
+
+ int callback (struct dirent *dirent, const char *pathname)
+ {
+ char buf[LINE_MAX];
+ ssize_t buf_len;
+
+ if ((dirent->d_type != DT_DIR && dirent->d_type != DT_LNK)
+ || (dirent->d_type == DT_DIR && strcmp (dirent->d_name, ".") != 0
+ && strcmp (dirent->d_name, "..") != 0)
+ || (dirent->d_type == DT_LNK && strspn (dirent->d_name, "0123456789")
+ != strlen (dirent->d_name)))
+ {
+ fprintf (stderr, "Unexpected entry \"%s\" (d_type %u)"
+ " on readdir (\"%s\"): %m\n",
+ dirent->d_name, (unsigned) dirent->d_type, dirname);
+ return 0;
+ }
+ if (dirent->d_type == DT_DIR)
+ return 0;
+ buf_len = readlink (pathname, buf, sizeof buf - 1);
+ if (buf_len <= 0 || buf_len >= (ssize_t) sizeof buf - 1)
+ {
+ if (errno != ENOENT && errno != EACCES)
+ fprintf (stderr, "Error reading link \"%s\": %m\n", pathname);
+ return 0;
+ }
+ buf[buf_len] = 0;
+ return (*func) (pid, buf);
+ }
+
+ return dir_scan (dirname, callback);
}
-static int rip_check (pid_t pid, const char *link)
+static void pid_fs_scan (void (*func) (pid_t pid, void *data), void *data)
+{
+ int callback (struct dirent *dirent, const char *pathname)
+ {
+ if (dirent->d_type != DT_DIR
+ || strspn (dirent->d_name, "0123456789") != strlen (dirent->d_name))
+ return 0;
+ (*func) (atoi (dirent->d_name), data);
+ return 0;
+ }
+
+ dir_scan ("/proc", callback);
+}
+
+static int rip_check_ptyname (pid_t pid, const char *link)
{
assert (pid != getpid ());
return 0;
}
+/* Single pass is not enough, a (multithreaded) process was seen to survive.
+ Repeated killing of the same process is not enough, zombies can be killed.
+ */
+static int cleanup_acted;
+
static void pid_record (pid_t pid)
{
struct pid *entry;
if (pid_found (pid))
return;
+ cleanup_acted = 1;
entry = malloc (sizeof (*entry));
if (entry == NULL)
{
pid_t parent_pid = *(pid_t *) data;
+ /* Do not optimize it as we could miss some newly spawned processes.
+ Always traverse all the leaves. */
+#if 0
/* Optimization. */
if (pid_found (pid))
return;
+#endif
if (pid_get_parent (pid) != parent_pid)
return;
/* Check both PGID and the stale file descriptors. */
pgid = getpgid (pid);
if (pgid == child
- || fd_fs_scan (pid, rip_check) != 0)
+ || fd_fs_scan (pid, rip_check_ptyname) != 0)
killtree (pid);
}
if (cmdline == NULL)
cmdline = "<error>";
fprintf (stderr, "%s: Killed -9 orphan PID %d: %s\n", progname, (int) pid, cmdline);
- if (kill (pid, SIGKILL))
- {
- if (errno != ESRCH)
- fprintf (stderr, "%s: kill (%d, SIGKILL): %m\n", progname, (int) pid);
- return;
- }
+ if (kill (pid, SIGKILL) == 0)
+ cleanup_acted = 1;
+ else if (errno != ESRCH)
+ fprintf (stderr, "%s: kill (%d, SIGKILL): %m\n", progname, (int) pid);
+ /* RHEL-3 kernels cannot SIGKILL a `T (stopped)' process. */
+ kill (pid, SIGCONT);
/* Do not waitpid(2) as it cannot be our direct descendant and it gets
cleaned up by init(8). */
#if 0
#endif
}
-static void rip ()
+static void rip (void)
{
- pid_fs_scan (rip_pid_fs_scan, NULL);
- pid_forall (killproc);
+ cleanup_acted = 0;
+ do
+ {
+ if (cleanup_acted)
+ usleep (1000000 / 10);
+ cleanup_acted = 0;
+ pid_fs_scan (rip_pid_fs_scan, NULL);
+ pid_forall (killproc);
+ }
+ while (cleanup_acted);
}
int main (int argc, char **argv)
{
+ int timeout = 0;
int rc;
- if (argc < 2 || strcmp (argv[1], "-h") == 0
- || strcmp (argv[1], "--help") == 0)
+ progname = *argv++;
+ argc--;
+
+ if (argc < 1 || strcmp (*argv, "-h") == 0
+ || strcmp (*argv, "--help") == 0)
{
- fputs ("Syntax: orphanripper <execvp(3) commandline>\n", stdout);
+ puts ("Syntax: orphanripper [-t <seconds>] <execvp(3) commandline>");
exit (EXIT_FAILURE);
}
- progname = argv[0];
- rc = spawn (argv);
+ if ((*argv)[0] == '-' && (*argv)[1] == 't')
+ {
+ char *timeout_s = NULL;
+
+ if ((*argv)[2] == 0)
+ timeout_s = *++argv;
+ else if (isdigit ((*argv)[2]))
+ timeout_s = (*argv) + 2;
+ if (timeout_s != NULL)
+ {
+ long l;
+ char *endptr;
+
+ argv++;
+ l = strtol (timeout_s, &endptr, 0);
+ timeout = l;
+ if ((endptr != NULL && *endptr != 0) || timeout < 0 || timeout != l)
+ {
+ fprintf (stderr, "%s: Invalid timeout value: %s\n", progname,
+ timeout_s);
+ exit (EXIT_FAILURE);
+ }
+ }
+ }
+
+ rc = spawn (argv, timeout);
rip ();
return rc;
}
git://git.jankratochvil.net / nethome.git / blobdiff