* 2007-07-10 Jan Kratochvil <jan.kratochvil@redhat.com>
*/
+/* For getpgid(2). */
#define _GNU_SOURCE 1
#include <stdio.h>
#include <pty.h>
#include <poll.h>
+#define LENGTH(x) (sizeof (x) / sizeof (*(x)))
+
static const char *progname;
static volatile int signal_child_hit = 0;
+/* We use it to race-safely emulate ppoll(2) by poll(2). */
+static int pipefd[2];
+
static void signal_child (int signo)
{
+ int i;
+
signal_child_hit = 1;
+
+ assert (pipefd[1] != -1);
+ i = close (pipefd[1]);
+ assert (i == 0);
+ pipefd[1] = -1;
}
static char childptyname[LINE_MAX];
pid_t child_got;
int status, amaster, i;
struct sigaction act;
- sigset_t sigset;
+ struct termios termios;
- /* 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);
+ i = pipe (pipefd);
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 have SA_RESTART set. */
memset (&act, 0, sizeof (act));
act.sa_handler = signal_child;
i = sigemptyset (&act.sa_mask);
assert (i == 0);
- act.sa_flags = 0;
+ act.sa_flags = SA_RESTART;
i = sigaction (SIGCHLD, &act, NULL);
assert (i == 0);
- child = forkpty (&amaster, childptyname, NULL, NULL);
+ /* 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:
+ i = close (pipefd[0]);
+ assert (i == 0);
+ i = close (pipefd[1]);
+ assert (i == 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
+
/* 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
}
for (;;)
{
- struct pollfd pollfd;
+ struct pollfd pollfd[2];
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 == 1 */
- assert (pollfd.revents != 0);
- if (pollfd.revents & POLLHUP)
- break;
- if (pollfd.revents != POLLIN)
+ pollfd[0].fd = amaster;
+ pollfd[0].events = POLLIN;
+ pollfd[1].fd = pipefd[0];
+ pollfd[1].events = POLLIN;
+ i = poll (pollfd, LENGTH (pollfd), -1);
+ if (i == -1 && errno == EINTR)
{
- fprintf (stderr, "%s: ppoll(2): revents 0x%x\n", progname,
- (unsigned) pollfd.revents);
- exit (EXIT_FAILURE);
+ /* Weird but SA_RESTART sometimes does not work. */
+ continue;
}
- buf_got = read (amaster, buf, sizeof buf);
- if (buf_got == 0)
- break;
- if (buf_got == -1)
+ assert (i >= 1);
+ /* Data available? Process it first. */
+ if (pollfd[0].revents & POLLIN)
{
- perror ("read (amaster)");
- exit (EXIT_FAILURE);
+ buf_got = read (amaster, buf, sizeof buf);
+ 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);
+ }
}
- if (write (STDOUT_FILENO, buf, buf_got) != buf_got)
+ if (pollfd[0].revents & POLLHUP)
+ break;
+ if ((pollfd[0].revents &= ~POLLIN) != 0)
{
- perror ("write(2)");
+ fprintf (stderr, "%s: ppoll(2): revents 0x%x\n", progname,
+ (unsigned) pollfd[0].revents);
exit (EXIT_FAILURE);
}
+ /* Child exited? */
+ if (pollfd[1].revents & POLLHUP)
+ break;
+ assert (pollfd[1].revents == 0);
}
/* WNOHANG still could fail. */
child_got = waitpid (child, &status, 0);
fprintf (stderr, "waitpid (%d): !WIFEXITED (%d)\n", (int) child, status);
exit (EXIT_FAILURE);
}
+
+ assert (signal_child_hit != 0);
+ assert (pipefd[1] == -1);
+ i = close (pipefd[0]);
+ assert (i == 0);
+
/* 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. */
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;
-
- /* 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)
+ char pathname[LINE_MAX];
+ int pathname_len;
+
+ pathname_len = snprintf (pathname, sizeof pathname, "%s/%s",
+ dirname, dirent->d_name);
+ if (pathname_len <= 0 || pathname_len >= 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 >= 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)