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author	Kurt Miller <kurt@cvs.openbsd.org>	2006-10-03 02:59:37 +0000
committer	Kurt Miller <kurt@cvs.openbsd.org>	2006-10-03 02:59:37 +0000
commit	985672e305143e6bee0ba4c190b0771bd2f8746e (patch)
tree	7871ff1c7df149af49e577edfd6cd33900013b09
parent	07706ccde7070f5695b2b92d66775c561609d513 (diff)

Last Part of file descriptor race and deadlock corrections.

When a fd enters the closing state prevent any threads from polling the fd and reschedule the thread with the closing_fd flag set. This fixes a class of deadlocks where a thread is blocked waiting for data (that may never arrive) and a later thread calls close() or dup2() on the fd. okay brad@

Diffstat

-rw-r--r--

lib/libpthread/uthread/pthread_private.h

-rw-r--r--

lib/libpthread/uthread/uthread_accept.c

-rw-r--r--

lib/libpthread/uthread/uthread_connect.c

-rw-r--r--

lib/libpthread/uthread/uthread_kern.c

-rw-r--r--

lib/libpthread/uthread/uthread_kevent.c

-rw-r--r--

lib/libpthread/uthread/uthread_poll.c

-rw-r--r--

lib/libpthread/uthread/uthread_read.c

-rw-r--r--

lib/libpthread/uthread/uthread_readv.c

-rw-r--r--

lib/libpthread/uthread/uthread_recvfrom.c

-rw-r--r--

lib/libpthread/uthread/uthread_recvmsg.c

-rw-r--r--

lib/libpthread/uthread/uthread_select.c

-rw-r--r--

lib/libpthread/uthread/uthread_sendmsg.c

-rw-r--r--

lib/libpthread/uthread/uthread_sendto.c

-rw-r--r--

lib/libpthread/uthread/uthread_write.c

-rw-r--r--

lib/libpthread/uthread/uthread_writev.c

15 files changed, 167 insertions, 49 deletions

diff --git a/lib/libpthread/uthread/pthread_private.h b/lib/libpthread/uthread/pthread_private.h
index 43e55c2b001..5011cd94d08 100644
--- a/lib/libpthread/uthread/pthread_private.h
+++ b/lib/libpthread/uthread/pthread_private.h

@@ -1,4 +1,4 @@

-/* $OpenBSD: pthread_private.h,v 1.57 2006/09/26 14:18:28 kurt Exp $ */

+/* $OpenBSD: pthread_private.h,v 1.58 2006/10/03 02:59:36 kurt Exp $ */

@@ -743,6 +743,12 @@ struct pthread {

int interrupted;

+ /*

+ * Set to TRUE if a blocking operation was

+ * interrupted by a closing file descriptor.

+ */

+ int closing_fd;

/* Signal number when in state PS_SIGWAIT: */

int signo;

diff --git a/lib/libpthread/uthread/uthread_accept.c b/lib/libpthread/uthread/uthread_accept.c
index caaa398dc8a..6fe193aa986 100644
--- a/lib/libpthread/uthread/uthread_accept.c
+++ b/lib/libpthread/uthread/uthread_accept.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: uthread_accept.c,v 1.10 2006/09/26 14:18:28 kurt Exp $ */

+/* $OpenBSD: uthread_accept.c,v 1.11 2006/10/03 02:59:36 kurt Exp $ */

@@ -67,6 +67,7 @@ accept(int fd, struct sockaddr * name, socklen_t *namelen)

/* Set the timeout: */

_thread_kern_set_timeout(NULL);

curthread->interrupted = 0;

+ curthread->closing_fd = 0;

/* Schedule the next thread: */

_thread_kern_sched_state(PS_FDR_WAIT, __FILE__,

@@ -78,6 +79,11 @@ accept(int fd, struct sockaddr * name, socklen_t *namelen)

errno = EINTR;

ret = -1;

break;

+ } else if (curthread->closing_fd) {

+ /* Return an error status: */

+ errno = EBADF;

+ ret = -1;

+ break;

}

} else {

diff --git a/lib/libpthread/uthread/uthread_connect.c b/lib/libpthread/uthread/uthread_connect.c
index 8987e1b56df..70dfd8ef430 100644
--- a/lib/libpthread/uthread/uthread_connect.c
+++ b/lib/libpthread/uthread/uthread_connect.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: uthread_connect.c,v 1.6 2006/09/22 19:04:33 kurt Exp $ */

+/* $OpenBSD: uthread_connect.c,v 1.7 2006/10/03 02:59:36 kurt Exp $ */

@@ -57,20 +57,38 @@ connect(int fd, const struct sockaddr * name, socklen_t namelen)

(errno == EALREADY) || (errno == EAGAIN))) {

curthread->data.fd.fd = fd;

+ /* Reset the interrupted operation flag: */

+ curthread->interrupted = 0;

+ curthread->closing_fd = 0;

/* Set the timeout: */

_thread_kern_set_timeout(NULL);

_thread_kern_sched_state(PS_FDW_WAIT, __FILE__, __LINE__);

- tmpnamelen = sizeof(tmpname);

- /* 0 now lets see if it really worked */

- if (((ret = _thread_sys_getpeername(fd, &tmpname, &tmpnamelen)) < 0) && (errno == ENOTCONN)) {

+ /*

+ * Check if the operation was

+ * interrupted by a signal or

+ * a closing fd.

+ */

+ if (curthread->interrupted) {

+ errno = EINTR;

+ ret = -1;

+ } else if (curthread->closing_fd) {

+ errno = EBADF;

+ ret = -1;

+ } else {

+ tmpnamelen = sizeof(tmpname);

+ /* 0 now lets see if it really worked */

+ if (((ret = _thread_sys_getpeername(fd, &tmpname, &tmpnamelen)) < 0) &&

+ (errno == ENOTCONN)) {

- /*

- * Get the error, this function

- * should not fail

- */

- errnolen = sizeof(errno);

- _thread_sys_getsockopt(fd, SOL_SOCKET, SO_ERROR, &errno, &errnolen);

+ /*

+ * Get the error, this function

+ * should not fail

+ */

+ errnolen = sizeof(errno);

+ _thread_sys_getsockopt(fd, SOL_SOCKET, SO_ERROR, &errno, &errnolen);

+ }

}

} else {

ret = -1;

diff --git a/lib/libpthread/uthread/uthread_kern.c b/lib/libpthread/uthread/uthread_kern.c
index 0210a4b3ecf..dd7fe641a9f 100644
--- a/lib/libpthread/uthread/uthread_kern.c
+++ b/lib/libpthread/uthread/uthread_kern.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: uthread_kern.c,v 1.31 2005/10/30 02:45:09 krw Exp $ */

+/* $OpenBSD: uthread_kern.c,v 1.32 2006/10/03 02:59:36 kurt Exp $ */

@@ -695,37 +695,69 @@ _thread_kern_poll(int wait_reqd)

/* File descriptor read wait: */

case PS_FDR_WAIT:

- /* Limit number of polled files to table size: */

- if (nfds < _thread_dtablesize) {

- _thread_pfd_table[nfds].events = POLLRDNORM;

- _thread_pfd_table[nfds].fd = pthread->data.fd.fd;

- nfds++;

+ /* if fd is closing then reschedule this thread */

+ if (_thread_fd_table[pthread->data.fd.fd]->state == FD_ENTRY_CLOSING) {

+ pthread->closing_fd = 1;

+ PTHREAD_WAITQ_CLEARACTIVE();

+ PTHREAD_WORKQ_REMOVE(pthread);

+ PTHREAD_NEW_STATE(pthread,PS_RUNNING);

+ PTHREAD_WAITQ_SETACTIVE();

+ } else {

+ /* Limit number of polled files to table size: */

+ if (nfds < _thread_dtablesize) {

+ _thread_pfd_table[nfds].events = POLLRDNORM;

+ _thread_pfd_table[nfds].fd = pthread->data.fd.fd;

+ nfds++;

+ }

}

break;

/* File descriptor write wait: */

case PS_FDW_WAIT:

- /* Limit number of polled files to table size: */

- if (nfds < _thread_dtablesize) {

- _thread_pfd_table[nfds].events = POLLWRNORM;

- _thread_pfd_table[nfds].fd = pthread->data.fd.fd;

- nfds++;

+ /* if fd is closing then reschedule this thread */

+ if (_thread_fd_table[pthread->data.fd.fd]->state == FD_ENTRY_CLOSING) {

+ pthread->closing_fd = 1;

+ PTHREAD_WAITQ_CLEARACTIVE();

+ PTHREAD_WORKQ_REMOVE(pthread);

+ PTHREAD_NEW_STATE(pthread,PS_RUNNING);

+ PTHREAD_WAITQ_SETACTIVE();

+ } else {

+ /* Limit number of polled files to table size: */

+ if (nfds < _thread_dtablesize) {

+ _thread_pfd_table[nfds].events = POLLWRNORM;

+ _thread_pfd_table[nfds].fd = pthread->data.fd.fd;

+ nfds++;

+ }

}

break;

/* File descriptor poll or select wait: */

case PS_POLL_WAIT:

case PS_SELECT_WAIT:

- /* Limit number of polled files to table size: */

- if (pthread->data.poll_data->nfds + nfds <

- _thread_dtablesize) {

- for (i = 0; i < pthread->data.poll_data->nfds; i++) {

- _thread_pfd_table[nfds + i].fd =

- pthread->data.poll_data->fds[i].fd;

- _thread_pfd_table[nfds + i].events =

- pthread->data.poll_data->fds[i].events;

+ /* if fd is closing then reschedule this thread */

+ for (i = 0; i < pthread->data.poll_data->nfds; i++) {

+ if (_thread_fd_table[pthread->data.poll_data->fds[i].fd]->state == FD_ENTRY_CLOSING) {

+ pthread->closing_fd = 1;

+ PTHREAD_WAITQ_CLEARACTIVE();

+ PTHREAD_WORKQ_REMOVE(pthread);

+ PTHREAD_NEW_STATE(pthread,PS_RUNNING);

+ PTHREAD_WAITQ_SETACTIVE();

+ break;

+ }

+ /* if the thread was not rescheduled by a closing fd then add files */

+ if (pthread->closing_fd == 0) {

+ /* Limit number of polled files to table size: */

+ if (pthread->data.poll_data->nfds + nfds <

+ _thread_dtablesize) {

+ for (i = 0; i < pthread->data.poll_data->nfds; i++) {

+ _thread_pfd_table[nfds + i].fd =

+ pthread->data.poll_data->fds[i].fd;

+ _thread_pfd_table[nfds + i].events =

+ pthread->data.poll_data->fds[i].events;

+ }

+ nfds += pthread->data.poll_data->nfds;

}

- nfds += pthread->data.poll_data->nfds;

}

break;

diff --git a/lib/libpthread/uthread/uthread_kevent.c b/lib/libpthread/uthread/uthread_kevent.c
index f687e70f7f1..e810900418a 100644
--- a/lib/libpthread/uthread/uthread_kevent.c
+++ b/lib/libpthread/uthread/uthread_kevent.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: uthread_kevent.c,v 1.4 2003/10/19 05:27:03 brad Exp $ */

+/* $OpenBSD: uthread_kevent.c,v 1.5 2006/10/03 02:59:36 kurt Exp $ */

/*-

@@ -60,6 +60,7 @@ kevent(int kq, const struct kevent *changelist, int nchanges,

do {

/* Reset the interrupted and timeout flags: */

curthread->interrupted = 0;

+ curthread->closing_fd = 0;

curthread->timeout = 0;

_thread_kern_sched_state(PS_FDR_WAIT,

@@ -69,6 +70,10 @@ kevent(int kq, const struct kevent *changelist, int nchanges,

errno = EINTR;

rc = -1;

break;

+ } else if (curthread->closing_fd) {

+ errno = EBADF;

+ rc = -1;

+ break;

}

rc = _thread_sys_kevent(kq, NULL, 0,

eventlist, nevents, &nullts);

diff --git a/lib/libpthread/uthread/uthread_poll.c b/lib/libpthread/uthread/uthread_poll.c
index dc276fa350a..48d25f38d9b 100644
--- a/lib/libpthread/uthread/uthread_poll.c
+++ b/lib/libpthread/uthread/uthread_poll.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: uthread_poll.c,v 1.11 2004/11/30 00:14:51 pat Exp $ */

+/* $OpenBSD: uthread_poll.c,v 1.12 2006/10/03 02:59:36 kurt Exp $ */

@@ -91,10 +91,14 @@ poll(struct pollfd fds[], nfds_t nfds, int timeout)

curthread->data.poll_data = &data;

curthread->interrupted = 0;

+ curthread->closing_fd = 0;

_thread_kern_sched_state(PS_POLL_WAIT, __FILE__, __LINE__);

if (curthread->interrupted) {

errno = EINTR;

ret = -1;

+ } else if (curthread->closing_fd) {

+ errno = EBADF;

+ ret = -1;

} else {

ret = data.nfds;

}

diff --git a/lib/libpthread/uthread/uthread_read.c b/lib/libpthread/uthread/uthread_read.c
index 8455c97d2f5..9c3ef425c52 100644
--- a/lib/libpthread/uthread/uthread_read.c
+++ b/lib/libpthread/uthread/uthread_read.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: uthread_read.c,v 1.8 2006/09/22 19:04:33 kurt Exp $ */

+/* $OpenBSD: uthread_read.c,v 1.9 2006/10/03 02:59:36 kurt Exp $ */

@@ -77,18 +77,24 @@ read(int fd, void *buf, size_t nbytes)

/* Reset the interrupted operation flag: */

curthread->interrupted = 0;

+ curthread->closing_fd = 0;

_thread_kern_sched_state(PS_FDR_WAIT,

__FILE__, __LINE__);

* Check if the operation was

- * interrupted by a signal

+ * interrupted by a signal or

+ * a closing fd.

if (curthread->interrupted) {

errno = EINTR;

ret = -1;

break;

+ } else if (curthread->closing_fd) {

+ errno = EBADF;

+ ret = -1;

+ break;

}

} else {

break;

diff --git a/lib/libpthread/uthread/uthread_readv.c b/lib/libpthread/uthread/uthread_readv.c
index a83002fb5c0..7019df3af52 100644
--- a/lib/libpthread/uthread/uthread_readv.c
+++ b/lib/libpthread/uthread/uthread_readv.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: uthread_readv.c,v 1.8 2006/09/22 19:04:33 kurt Exp $ */

+/* $OpenBSD: uthread_readv.c,v 1.9 2006/10/03 02:59:36 kurt Exp $ */

@@ -75,18 +75,24 @@ readv(int fd, const struct iovec * iov, int iovcnt)

/* Reset the interrupted operation flag: */

curthread->interrupted = 0;

+ curthread->closing_fd = 0;

_thread_kern_sched_state(PS_FDR_WAIT,

__FILE__, __LINE__);

* Check if the operation was

- * interrupted by a signal

+ * interrupted by a signal or

+ * a closing fd.

if (curthread->interrupted) {

errno = EINTR;

ret = -1;

break;

+ } else if (curthread->closing_fd) {

+ errno = EBADF;

+ ret = -1;

+ break;

}

} else {

break;

diff --git a/lib/libpthread/uthread/uthread_recvfrom.c b/lib/libpthread/uthread/uthread_recvfrom.c
index 0c693de57a1..21ff7e3f6a5 100644
--- a/lib/libpthread/uthread/uthread_recvfrom.c
+++ b/lib/libpthread/uthread/uthread_recvfrom.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: uthread_recvfrom.c,v 1.7 2006/09/22 19:04:33 kurt Exp $ */

+/* $OpenBSD: uthread_recvfrom.c,v 1.8 2006/10/03 02:59:36 kurt Exp $ */

@@ -58,6 +58,7 @@ recvfrom(int fd, void *buf, size_t len, int flags, struct sockaddr * from, sockl

/* Set the timeout: */

_thread_kern_set_timeout(NULL);

curthread->interrupted = 0;

+ curthread->closing_fd = 0;

_thread_kern_sched_state(PS_FDR_WAIT, __FILE__, __LINE__);

/* Check if the wait was interrupted: */

@@ -66,6 +67,11 @@ recvfrom(int fd, void *buf, size_t len, int flags, struct sockaddr * from, sockl

errno = EINTR;

ret = -1;

break;

+ } else if (curthread->closing_fd) {

+ /* Return an error status: */

+ errno = EBADF;

+ ret = -1;

+ break;

}

} else {

ret = -1;

diff --git a/lib/libpthread/uthread/uthread_recvmsg.c b/lib/libpthread/uthread/uthread_recvmsg.c
index 5e8f13bd6dc..fa455395938 100644
--- a/lib/libpthread/uthread/uthread_recvmsg.c
+++ b/lib/libpthread/uthread/uthread_recvmsg.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: uthread_recvmsg.c,v 1.6 2006/09/22 19:04:33 kurt Exp $ */

+/* $OpenBSD: uthread_recvmsg.c,v 1.7 2006/10/03 02:59:36 kurt Exp $ */

@@ -58,6 +58,7 @@ recvmsg(int fd, struct msghdr *msg, int flags)

/* Set the timeout: */

_thread_kern_set_timeout(NULL);

curthread->interrupted = 0;

+ curthread->closing_fd = 0;

_thread_kern_sched_state(PS_FDR_WAIT, __FILE__, __LINE__);

/* Check if the wait was interrupted: */

@@ -66,6 +67,11 @@ recvmsg(int fd, struct msghdr *msg, int flags)

errno = EINTR;

ret = -1;

break;

+ } else if (curthread->closing_fd) {

+ /* Return an error status: */

+ errno = EBADF;

+ ret = -1;

+ break;

}

} else {

ret = -1;

diff --git a/lib/libpthread/uthread/uthread_select.c b/lib/libpthread/uthread/uthread_select.c
index acc5d3017ae..f360ef2b425 100644
--- a/lib/libpthread/uthread/uthread_select.c
+++ b/lib/libpthread/uthread/uthread_select.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: uthread_select.c,v 1.11 2004/01/03 07:35:10 brad Exp $ */

+/* $OpenBSD: uthread_select.c,v 1.12 2006/10/03 02:59:36 kurt Exp $ */

@@ -165,11 +165,16 @@ select(int numfds, fd_set * readfds, fd_set * writefds,

(f_wait != 0)) {

curthread->data.poll_data = &data;

curthread->interrupted = 0;

+ curthread->closing_fd = 0;

_thread_kern_sched_state(PS_SELECT_WAIT, __FILE__, __LINE__);

if (curthread->interrupted) {

errno = EINTR;

data.nfds = 0;

ret = -1;

+ } else if (curthread->closing_fd) {

+ errno = EBADF;

+ data.nfds = 0;

+ ret = -1;

} else

ret = data.nfds;

}

diff --git a/lib/libpthread/uthread/uthread_sendmsg.c b/lib/libpthread/uthread/uthread_sendmsg.c
index 7cfb714606a..2995af1e024 100644
--- a/lib/libpthread/uthread/uthread_sendmsg.c
+++ b/lib/libpthread/uthread/uthread_sendmsg.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: uthread_sendmsg.c,v 1.6 2006/09/22 19:04:33 kurt Exp $ */

+/* $OpenBSD: uthread_sendmsg.c,v 1.7 2006/10/03 02:59:36 kurt Exp $ */

@@ -58,6 +58,7 @@ sendmsg(int fd, const struct msghdr *msg, int flags)

/* Set the timeout: */

_thread_kern_set_timeout(NULL);

curthread->interrupted = 0;

+ curthread->closing_fd = 0;

_thread_kern_sched_state(PS_FDW_WAIT, __FILE__, __LINE__);

/* Check if the operation was interrupted: */

@@ -65,6 +66,10 @@ sendmsg(int fd, const struct msghdr *msg, int flags)

errno = EINTR;

ret = -1;

break;

+ } else if (curthread->closing_fd) {

+ errno = EBADF;

+ ret = -1;

+ break;

}

} else {

ret = -1;

diff --git a/lib/libpthread/uthread/uthread_sendto.c b/lib/libpthread/uthread/uthread_sendto.c
index 5b342315da3..09b1644d659 100644
--- a/lib/libpthread/uthread/uthread_sendto.c
+++ b/lib/libpthread/uthread/uthread_sendto.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: uthread_sendto.c,v 1.7 2006/09/22 19:04:33 kurt Exp $ */

+/* $OpenBSD: uthread_sendto.c,v 1.8 2006/10/03 02:59:36 kurt Exp $ */

@@ -58,6 +58,7 @@ sendto(int fd, const void *msg, size_t len, int flags, const struct sockaddr * t

/* Set the timeout: */

_thread_kern_set_timeout(NULL);

curthread->interrupted = 0;

+ curthread->closing_fd = 0;

_thread_kern_sched_state(PS_FDW_WAIT, __FILE__, __LINE__);

/* Check if the operation was interrupted: */

@@ -65,6 +66,10 @@ sendto(int fd, const void *msg, size_t len, int flags, const struct sockaddr * t

errno = EINTR;

ret = -1;

break;

+ } else if (curthread->closing_fd) {

+ errno = EBADF;

+ ret = -1;

+ break;

}

} else {

ret = -1;

diff --git a/lib/libpthread/uthread/uthread_write.c b/lib/libpthread/uthread/uthread_write.c
index 71581d05387..2c4ed1076ff 100644
--- a/lib/libpthread/uthread/uthread_write.c
+++ b/lib/libpthread/uthread/uthread_write.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: uthread_write.c,v 1.11 2006/09/22 19:04:33 kurt Exp $ */

+/* $OpenBSD: uthread_write.c,v 1.12 2006/10/03 02:59:36 kurt Exp $ */

@@ -105,6 +105,7 @@ write(int fd, const void *buf, size_t nbytes)

/* Reset the interrupted operation flag: */

curthread->interrupted = 0;

+ curthread->closing_fd = 0;

_thread_kern_sched_state(PS_FDW_WAIT,

__FILE__, __LINE__);

@@ -113,13 +114,16 @@ write(int fd, const void *buf, size_t nbytes)

* Check if the operation was

* interrupted by a signal

- if (curthread->interrupted) {

+ if (curthread->interrupted || curthread->closing_fd) {

if (num > 0) {

/* Return partial success: */

ret = num;

} else {

/* Return an error: */

- errno = EINTR;

+ if (curthread->closing_fd)

+ errno = EBADF;

+ else

+ errno = EINTR;

ret = -1;

}

diff --git a/lib/libpthread/uthread/uthread_writev.c b/lib/libpthread/uthread/uthread_writev.c
index cf7733f6290..45b1c80a2ee 100644
--- a/lib/libpthread/uthread/uthread_writev.c
+++ b/lib/libpthread/uthread/uthread_writev.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: uthread_writev.c,v 1.11 2006/09/22 19:04:33 kurt Exp $ */

+/* $OpenBSD: uthread_writev.c,v 1.12 2006/10/03 02:59:36 kurt Exp $ */

@@ -174,6 +174,7 @@ writev(int fd, const struct iovec * iov, int iovcnt)

/* Reset the interrupted operation flag: */

curthread->interrupted = 0;

+ curthread->closing_fd = 0;

_thread_kern_sched_state(PS_FDW_WAIT,

__FILE__, __LINE__);

@@ -182,13 +183,16 @@ writev(int fd, const struct iovec * iov, int iovcnt)

* Check if the operation was

* interrupted by a signal

- if (curthread->interrupted) {

+ if (curthread->interrupted || curthread->closing_fd) {

if (num > 0) {

/* Return partial success: */

ret = num;

} else {

/* Return an error: */

- errno = EINTR;

+ if (curthread->closing_fd)

+ errno = EBADF;

+ else

+ errno = EINTR;

ret = -1;

}