diff --git a/libunwind-orphanripper.c b/libunwind-orphanripper.c new file mode 100644 index 0000000..9d5d8df --- /dev/null +++ b/libunwind-orphanripper.c @@ -0,0 +1,690 @@ +/* + * Copyright 2006-2007 Free Software Foundation, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * Reap any leftover children possibly holding file descriptors. + * Children are identified by the stale file descriptor or PGID / SID. + * Both can be missed but only the stale file descriptors are important for us. + * PGID / SID may be set by the children on their own. + * If we fine a candidate we kill it will all its process tree (grandchildren). + * The child process is run with `2>&1' redirection (due to forkpty(3)). + * 2007-07-10 Jan Kratochvil + */ + +/* For getpgid(2). */ +#define _GNU_SOURCE 1 + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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 volatile int signal_alarm_hit = 0; + +static void signal_alarm (int signo) +{ + signal_alarm_hit = 1; +} + +static char childptyname[LINE_MAX]; +static pid_t child; + +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 spawn (char **argv, int timeout) +{ + pid_t child_got; + int status, amaster, i, rc; + struct sigaction act; + struct termios termios; + unsigned alarm_orig; + + i = pipe (pipefd); + assert (i == 0); + + /* 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 = SA_RESTART; + i = sigaction (SIGCHLD, &act, 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: + 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 + command in the pipeline. + We would rip even vi(1) in the case of: + ./orphanripper sh -c 'sleep 1&' | vi - + */ + /* Do not setpgrp(2) as our pty would not be ours and we would + get `SIGSTOP' later, particularly after spawning gdb(1). + setsid(3) was already executed by forkpty(3) and it would fail if + executed again. */ + if (getpid() != getpgrp ()) + { + perror ("getpgrp(2)"); + exit (EXIT_FAILURE); + } + execvp (argv[0], argv); + perror ("execvp(2)"); + exit (EXIT_FAILURE); + default: + break; + } + i = fcntl (amaster, F_SETFL, O_RDWR | O_NONBLOCK); + if (i != 0) + { + perror ("fcntl (amaster, F_SETFL, O_NONBLOCK)"); + exit (EXIT_FAILURE); + } + + /* We do not use signal(2) to be sure we have SA_RESTART set. */ + act.sa_handler = signal_alarm; + act.sa_flags &= ~SA_RESTART; + i = sigaction (SIGALRM, &act, NULL); + assert (i == 0); + + alarm_orig = alarm (timeout); + assert (alarm_orig == 0); + + while (!signal_alarm_hit) + { + struct pollfd pollfd[2]; + char buf[LINE_MAX]; + ssize_t buf_got; + + 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) + { + /* Weird but SA_RESTART sometimes does not work. */ + continue; + } + assert (i >= 1); + /* Data available? Process it first. */ + if (pollfd[0].revents & POLLIN) + { + 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 (pollfd[0].revents & POLLHUP) + break; + if ((pollfd[0].revents &= ~POLLIN) != 0) + { + 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); + } + + if (signal_alarm_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 (signal_alarm_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); + } + + 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. */ +#if 0 + i = close (amaster); + if (i != 0) + { + perror ("close (forkpty ()'s amaster)"); + exit (EXIT_FAILURE); + } +#endif + + return rc; +} + +/* Detected commandline may look weird due to a race: + Original command: + ./orphanripper sh -c 'sleep 1&' & + Correct output: + [1] 29610 + ./orphanripper: Killed -9 orphan PID 29612 (PGID 29611): sleep 1 + Raced output (sh(1) child still did not update its argv[]): + [1] 29613 + ./orphanripper: Killed -9 orphan PID 29615 (PGID 29614): sh -c sleep 1& + We could delay a bit before ripping the children. */ +static const char *read_cmdline (pid_t pid) +{ + char cmdline_fname[32]; + static char cmdline[LINE_MAX]; + int fd; + ssize_t got; + char *s; + + if (snprintf (cmdline_fname, sizeof cmdline_fname, "/proc/%d/cmdline", + (int) pid) < 0) + return NULL; + fd = open (cmdline_fname, O_RDONLY); + if (fd == -1) + { + /* It may have already exited - ENOENT. */ +#if 0 + fprintf (stderr, "%s: open (\"%s\"): %m\n", progname, cmdline_fname); +#endif + return NULL; + } + got = read (fd, cmdline, sizeof (cmdline) - 1); + if (got == -1) + fprintf (stderr, "%s: read (\"%s\"): %m\n", progname, + cmdline_fname); + if (close (fd) != 0) + fprintf (stderr, "%s: close (\"%s\"): %m\n", progname, + cmdline_fname); + if (got < 0) + return NULL; + /* Convert '\0' argument delimiters to spaces. */ + for (s = cmdline; s < cmdline + got; s++) + if (!*s) + *s = ' '; + /* Trim the trailing spaces (typically single '\0'->' '). */ + while (s > cmdline && isspace (s[-1])) + s--; + *s = 0; + return cmdline; +} + +static int dir_scan (const char *dirname, + int (*callback) (struct dirent *dirent, const char *pathname)) +{ + DIR *dir; + struct dirent *dirent; + int rc = 0; + + dir = opendir (dirname); + if (dir == NULL) + { + if (errno == EACCES || errno == ENOENT) + return rc; + fprintf (stderr, "%s: opendir (\"%s\"): %m\n", progname, dirname); + exit (EXIT_FAILURE); + } + while ((errno = 0, dirent = readdir (dir))) + { + 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 >= (int) sizeof pathname) + { + fprintf (stderr, "entry file name too long: `%s' / `%s'\n", + dirname, dirent->d_name); + 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. */ + } + rc = (*callback) (dirent, pathname); + if (rc != 0) + { + errno = 0; + break; + } + } + if (errno != 0) + { + fprintf (stderr, "%s: readdir (\"%s\"): %m\n", progname, dirname); + exit (EXIT_FAILURE); + } + if (closedir (dir) != 0) + { + fprintf (stderr, "%s: closedir (\"%s\"): %m\n", progname, dirname); + exit (EXIT_FAILURE); + } + return rc; +} + +static int fd_fs_scan (pid_t pid, int (*func) (pid_t pid, const char *link)) +{ + char dirname[64]; + + if (snprintf (dirname, sizeof dirname, "/proc/%d/fd", (int) pid) < 0) + { + 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 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 strcmp (link, childptyname) == 0; +} + +struct pid + { + struct pid *next; + pid_t pid; + }; +static struct pid *pid_list; + +static int pid_found (pid_t pid) +{ + struct pid *entry; + + for (entry = pid_list; entry != NULL; entry = entry->next) + if (entry->pid == pid) + return 1; + 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) + { + fprintf (stderr, "%s: malloc: %m\n", progname); + exit (EXIT_FAILURE); + } + entry->pid = pid; + entry->next = pid_list; + pid_list = entry; +} + +static void pid_forall (void (*func) (pid_t pid)) +{ + struct pid *entry; + + for (entry = pid_list; entry != NULL; entry = entry->next) + (*func) (entry->pid); +} + +/* Returns 0 on failure. */ +static pid_t pid_get_parent (pid_t pid) +{ + char fname[64]; + FILE *f; + char line[LINE_MAX]; + pid_t retval = 0; + + if (snprintf (fname, sizeof fname, "/proc/%d/status", (int) pid) < 0) + { + perror ("snprintf(3)"); + exit (EXIT_FAILURE); + } + f = fopen (fname, "r"); + if (f == NULL) + { + return 0; + } + while (errno = 0, fgets (line, sizeof line, f) == line) + { + if (strncmp (line, "PPid:\t", sizeof "PPid:\t" - 1) != 0) + continue; + retval = atoi (line + sizeof "PPid:\t" - 1); + errno = 0; + break; + } + if (errno != 0) + { + fprintf (stderr, "%s: fgets (\"%s\"): %m\n", progname, fname); + exit (EXIT_FAILURE); + } + if (fclose (f) != 0) + { + fprintf (stderr, "%s: fclose (\"%s\"): %m\n", progname, fname); + exit (EXIT_FAILURE); + } + return retval; +} + +static void killtree (pid_t pid); + +static void killtree_pid_fs_scan (pid_t pid, void *data) +{ + 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; + + killtree (pid); +} + +static void killtree (pid_t pid) +{ + pid_record (pid); + pid_fs_scan (killtree_pid_fs_scan, &pid); +} + +static void rip_pid_fs_scan (pid_t pid, void *data) +{ + pid_t pgid; + + /* Shouldn't happen. */ + if (pid == getpid ()) + return; + + /* Check both PGID and the stale file descriptors. */ + pgid = getpgid (pid); + if (pgid == child + || fd_fs_scan (pid, rip_check_ptyname) != 0) + killtree (pid); +} + +static void killproc (pid_t pid) +{ + const char *cmdline; + + cmdline = read_cmdline (pid); + /* Avoid printing the message for already gone processes. */ + if (kill (pid, 0) != 0 && errno == ESRCH) + return; + if (cmdline == NULL) + cmdline = ""; + fprintf (stderr, "%s: Killed -9 orphan PID %d: %s\n", progname, (int) pid, cmdline); + 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 + pid_t pid_got; + pid_got = waitpid (pid, NULL, 0); + if (pid != pid_got) + { + fprintf (stderr, "%s: waitpid (%d) != %d: %m\n", progname, + (int) pid, (int) pid_got); + return; + } +#endif +} + +static void rip (void) +{ + 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; + + progname = *argv++; + argc--; + + if (argc < 1 || strcmp (*argv, "-h") == 0 + || strcmp (*argv, "--help") == 0) + { + puts ("Syntax: orphanripper [-t ] "); + exit (EXIT_FAILURE); + } + 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; +} diff --git a/libunwind-snap-070224-orphanripper.patch b/libunwind-snap-070224-orphanripper.patch new file mode 100644 index 0000000..aa8f220 --- /dev/null +++ b/libunwind-snap-070224-orphanripper.patch @@ -0,0 +1,14 @@ +diff -u -X /home/jkratoch/.diffi.list -rup libunwind-0.99-alpha-orig/tests/Makefile.am libunwind-0.99-alpha/tests/Makefile.am +--- libunwind-0.99-alpha-orig/tests/Makefile.am 2008-02-23 07:58:30.000000000 +0100 ++++ libunwind-0.99-alpha/tests/Makefile.am 2008-02-23 18:59:09.000000000 +0100 +@@ -4,7 +4,9 @@ EXTRA_DIST = run-ia64-test-dyn1 run-ptra + run-check-namespace check-namespace.sh.in run-ptrace-signull \ + run-ptrace-stepper + +-noinst_PROGRAMS_common = ++noinst_PROGRAMS_common = orphanripper ++orphanripper_LDADD = -lutil ++TESTS_ENVIRONMENT = ./orphanripper -t 120 + check_PROGRAMS_common = test-proc-info test-static-link \ + test-strerror + check_SCRIPTS_common = run-check-namespace diff --git a/libunwind.spec b/libunwind.spec index 49843cd..e2d2138 100644 --- a/libunwind.spec +++ b/libunwind.spec @@ -8,11 +8,13 @@ Name: libunwind Version: 0.99 %define frysksnap 20070405cvs %define upstreamsnap 070224 -Release: 0.3.frysk%{frysksnap}%{?dist} +Release: 0.4.frysk%{frysksnap}%{?dist} License: BSD Group: Development/Debuggers Source: http://download.savannah.nongnu.org/releases/libunwind/libunwind-snap-%{upstreamsnap}.tar.gz Patch1: libunwind-snap-%{upstreamsnap}-frysk%{frysksnap}.patch +Patch2: libunwind-snap-070224-orphanripper.patch +Source1: libunwind-orphanripper.c Buildroot: %(mktemp -ud %{_tmppath}/%{name}-%{version}-%{release}-XXXXXX) URL: http://savannah.nongnu.org/projects/libunwind ExclusiveArch: ia64 x86_64 i386 ppc64 @@ -41,6 +43,9 @@ libunwind. chmod +x tests/run-ptrace-stepper chmod +x tests/run-ptrace-signull +%patch2 -p1 -E +cp -p %{SOURCE1} tests/orphanripper.c + %build mkdir -p config aclocal @@ -77,6 +82,9 @@ rm -rf $RPM_BUILD_ROOT %{_includedir}/* %changelog +* Sun Feb 24 2008 Jan Kratochvil - 0.99-0.4.frysk20070405cvs +- Abort the possibly hung up testcases after 120 seconds (BZ 427850, BZ 434147). + * Tue Feb 19 2008 Fedora Release Engineering - 0.99-0.3.frysk20070405cvs - Autorebuild for GCC 4.3