* [PATCH] pty: Fix input race when closing [not found] <55118928.1090203@hurleysoftware.com> @ 2015-04-09 14:54 ` Peter Hurley 2015-04-09 17:43 ` H.J. Lu 0 siblings, 1 reply; 5+ messages in thread From: Peter Hurley @ 2015-04-09 14:54 UTC (permalink / raw) To: Greg Kroah-Hartman Cc: Jiri Slaby, linux-kernel, Alan Cox, Andy Whitcroft, H.J. Lu, Josh Boyer, Peter Hurley, stable A read() from a pty master may mistakenly indicate EOF (errno == -EIO) after the pty slave has closed, even though input data remains to be read. For example, pty slave | input worker | pty master | | | | n_tty_read() pty_write() | | input avail? no add data | | sleep schedule worker --->| | . |---> flush_to_ldisc() | . pty_close() | fill read buffer | . wait for worker | wakeup reader --->| . | read buffer full? |---> input avail ? yes |<--- yes - exit worker | copy 4096 bytes to user TTY_OTHER_CLOSED <---| |<--- kick worker | | **** New read() before worker starts **** | | n_tty_read() | | input avail? no | | TTY_OTHER_CLOSED? yes | | return -EIO Several conditions are required to trigger this race: 1. the ldisc read buffer must become full so the input worker exits 2. the read() count parameter must be >= 4096 so the ldisc read buffer is empty 3. the subsequent read() occurs before the kicked worker has processed more input However, the underlying cause of the race is that data is pipelined, while tty state is not; ie., data already written by the pty slave end is not yet visible to the pty master end, but state changes by the pty slave end are visible to the pty master end immediately. Pipeline the TTY_OTHER_CLOSED state through input worker to the reader. 1. Introduce TTY_OTHER_DONE which is set by the input worker when TTY_OTHER_CLOSED is set and either the input buffers are flushed or input processing has completed. Readers/polls are woken when TTY_OTHER_DONE is set. 2. Reader/poll checks TTY_OTHER_DONE instead of TTY_OTHER_CLOSED. 3. A new input worker is started from pty_close() after setting TTY_OTHER_CLOSED, which ensures the TTY_OTHER_DONE state will be set if the last input worker is already finished (or just about to exit). Remove tty_flush_to_ldisc(); no in-tree callers. Fixes: 52bce7f8d4fc ("pty, n_tty: Simplify input processing on final close") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=96311 BugLink: http://bugs.launchpad.net/bugs/1429756 Cc: <stable@vger.kernel.org> # 3.19+ Reported-by: Andy Whitcroft <apw@canonical.com> Reported-by: H.J. Lu <hjl.tools@gmail.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> --- Documentation/serial/tty.txt | 3 +++ drivers/tty/n_hdlc.c | 4 ++-- drivers/tty/n_tty.c | 4 ++-- drivers/tty/pty.c | 3 +-- drivers/tty/tty_buffer.c | 25 +++++++++++-------------- include/linux/tty.h | 2 +- 6 files changed, 20 insertions(+), 21 deletions(-) diff --git a/Documentation/serial/tty.txt b/Documentation/serial/tty.txt index 1e52d67..dbe6623 100644 --- a/Documentation/serial/tty.txt +++ b/Documentation/serial/tty.txt @@ -198,6 +198,9 @@ TTY_IO_ERROR If set, causes all subsequent userspace read/write TTY_OTHER_CLOSED Device is a pty and the other side has closed. +TTY_OTHER_DONE Device is a pty and the other side has closed and + all pending input processing has been completed. + TTY_NO_WRITE_SPLIT Prevent driver from splitting up writes into smaller chunks. diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c index 644ddb8..bbc4ce6 100644 --- a/drivers/tty/n_hdlc.c +++ b/drivers/tty/n_hdlc.c @@ -600,7 +600,7 @@ static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file, add_wait_queue(&tty->read_wait, &wait); for (;;) { - if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) { + if (test_bit(TTY_OTHER_DONE, &tty->flags)) { ret = -EIO; break; } @@ -828,7 +828,7 @@ static unsigned int n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp, /* set bits for operations that won't block */ if (n_hdlc->rx_buf_list.head) mask |= POLLIN | POLLRDNORM; /* readable */ - if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) + if (test_bit(TTY_OTHER_DONE, &tty->flags)) mask |= POLLHUP; if (tty_hung_up_p(filp)) mask |= POLLHUP; diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 54da8f4..522de6d 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -2233,7 +2233,7 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, ldata->minimum_to_wake = (minimum - (b - buf)); if (!input_available_p(tty, 0)) { - if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) { + if (test_bit(TTY_OTHER_DONE, &tty->flags)) { retval = -EIO; break; } @@ -2444,7 +2444,7 @@ static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file, mask |= POLLIN | POLLRDNORM; if (tty->packet && tty->link->ctrl_status) mask |= POLLPRI | POLLIN | POLLRDNORM; - if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) + if (test_bit(TTY_OTHER_DONE, &tty->flags)) mask |= POLLHUP; if (tty_hung_up_p(file)) mask |= POLLHUP; diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index 6fffb53..ebcff90 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -59,9 +59,8 @@ static void pty_close(struct tty_struct *tty, struct file *filp) /* Review - krefs on tty_link ?? */ if (!tty->link) return; - tty_flush_to_ldisc(tty->link); set_bit(TTY_OTHER_CLOSED, &tty->link->flags); - wake_up_interruptible(&tty->link->read_wait); + tty_flip_buffer_push(tty->link->port); wake_up_interruptible(&tty->link->write_wait); if (tty->driver->subtype == PTY_TYPE_MASTER) { set_bit(TTY_OTHER_CLOSED, &tty->flags); diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c index 7566164..642dcd0 100644 --- a/drivers/tty/tty_buffer.c +++ b/drivers/tty/tty_buffer.c @@ -229,6 +229,11 @@ void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld) if (ld && ld->ops->flush_buffer) ld->ops->flush_buffer(tty); + if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) { + set_bit(TTY_OTHER_DONE, &tty->flags); + wake_up_interruptible(&tty->read_wait); + } + atomic_dec(&buf->priority); mutex_unlock(&buf->lock); } @@ -471,8 +476,13 @@ static void flush_to_ldisc(struct work_struct *work) smp_rmb(); count = head->commit - head->read; if (!count) { - if (next == NULL) + if (next == NULL) { + if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) { + set_bit(TTY_OTHER_DONE, &tty->flags); + wake_up_interruptible(&tty->read_wait); + } break; + } buf->head = next; tty_buffer_free(port, head); continue; @@ -489,19 +499,6 @@ static void flush_to_ldisc(struct work_struct *work) } /** - * tty_flush_to_ldisc - * @tty: tty to push - * - * Push the terminal flip buffers to the line discipline. - * - * Must not be called from IRQ context. - */ -void tty_flush_to_ldisc(struct tty_struct *tty) -{ - flush_work(&tty->port->buf.work); -} - -/** * tty_flip_buffer_push - terminal * @port: tty port to push * diff --git a/include/linux/tty.h b/include/linux/tty.h index f9fbdf1..0f29f31 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -339,6 +339,7 @@ struct tty_file_private { #define TTY_EXCLUSIVE 3 /* Exclusive open mode */ #define TTY_DEBUG 4 /* Debugging */ #define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */ +#define TTY_OTHER_DONE 6 /* Closed pty has completed input processing */ #define TTY_LDISC_OPEN 11 /* Line discipline is open */ #define TTY_PTY_LOCK 16 /* pty private */ #define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */ @@ -462,7 +463,6 @@ extern int tty_hung_up_p(struct file *filp); extern void do_SAK(struct tty_struct *tty); extern void __do_SAK(struct tty_struct *tty); extern void no_tty(void); -extern void tty_flush_to_ldisc(struct tty_struct *tty); extern void tty_buffer_free_all(struct tty_port *port); extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld); extern void tty_buffer_init(struct tty_port *port); -- 2.3.5 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] pty: Fix input race when closing 2015-04-09 14:54 ` [PATCH] pty: Fix input race when closing Peter Hurley @ 2015-04-09 17:43 ` H.J. Lu 2015-04-09 17:53 ` Peter Hurley 0 siblings, 1 reply; 5+ messages in thread From: H.J. Lu @ 2015-04-09 17:43 UTC (permalink / raw) To: Peter Hurley Cc: Greg Kroah-Hartman, Jiri Slaby, LKML, Alan Cox, Andy Whitcroft, Josh Boyer, stable On Thu, Apr 9, 2015 at 7:54 AM, Peter Hurley <peter@hurleysoftware.com> wrote: > A read() from a pty master may mistakenly indicate EOF (errno == -EIO) > after the pty slave has closed, even though input data remains to be read. > For example, > > pty slave | input worker | pty master > | | > | | n_tty_read() > pty_write() | | input avail? no > add data | | sleep > schedule worker --->| | . > |---> flush_to_ldisc() | . > pty_close() | fill read buffer | . > wait for worker | wakeup reader --->| . > | read buffer full? |---> input avail ? yes > |<--- yes - exit worker | copy 4096 bytes to user > TTY_OTHER_CLOSED <---| |<--- kick worker > | | > > **** New read() before worker starts **** > > | | n_tty_read() > | | input avail? no > | | TTY_OTHER_CLOSED? yes > | | return -EIO > > Several conditions are required to trigger this race: > 1. the ldisc read buffer must become full so the input worker exits > 2. the read() count parameter must be >= 4096 so the ldisc read buffer > is empty > 3. the subsequent read() occurs before the kicked worker has processed > more input > > However, the underlying cause of the race is that data is pipelined, while > tty state is not; ie., data already written by the pty slave end is not > yet visible to the pty master end, but state changes by the pty slave end > are visible to the pty master end immediately. > > Pipeline the TTY_OTHER_CLOSED state through input worker to the reader. > 1. Introduce TTY_OTHER_DONE which is set by the input worker when > TTY_OTHER_CLOSED is set and either the input buffers are flushed or > input processing has completed. Readers/polls are woken when > TTY_OTHER_DONE is set. > 2. Reader/poll checks TTY_OTHER_DONE instead of TTY_OTHER_CLOSED. > 3. A new input worker is started from pty_close() after setting > TTY_OTHER_CLOSED, which ensures the TTY_OTHER_DONE state will be > set if the last input worker is already finished (or just about to > exit). > > Remove tty_flush_to_ldisc(); no in-tree callers. > > Fixes: 52bce7f8d4fc ("pty, n_tty: Simplify input processing on final close") > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=96311 > BugLink: http://bugs.launchpad.net/bugs/1429756 > Cc: <stable@vger.kernel.org> # 3.19+ > Reported-by: Andy Whitcroft <apw@canonical.com> > Reported-by: H.J. Lu <hjl.tools@gmail.com> > Signed-off-by: Peter Hurley <peter@hurleysoftware.com> > --- > Documentation/serial/tty.txt | 3 +++ > drivers/tty/n_hdlc.c | 4 ++-- > drivers/tty/n_tty.c | 4 ++-- > drivers/tty/pty.c | 3 +-- > drivers/tty/tty_buffer.c | 25 +++++++++++-------------- > include/linux/tty.h | 2 +- > 6 files changed, 20 insertions(+), 21 deletions(-) > I tried it on 3.19.3 and it doesn't work with the testcase in https://bugzilla.kernel.org/show_bug.cgi?id=96311 -- H.J. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] pty: Fix input race when closing 2015-04-09 17:43 ` H.J. Lu @ 2015-04-09 17:53 ` Peter Hurley 2015-04-09 17:55 ` H.J. Lu 2015-04-09 22:11 ` H.J. Lu 0 siblings, 2 replies; 5+ messages in thread From: Peter Hurley @ 2015-04-09 17:53 UTC (permalink / raw) To: H.J. Lu Cc: Greg Kroah-Hartman, Jiri Slaby, LKML, Alan Cox, Andy Whitcroft, Josh Boyer, stable On 04/09/2015 01:43 PM, H.J. Lu wrote: > On Thu, Apr 9, 2015 at 7:54 AM, Peter Hurley <peter@hurleysoftware.com> wrote: >> A read() from a pty master may mistakenly indicate EOF (errno == -EIO) >> after the pty slave has closed, even though input data remains to be read. >> For example, >> >> pty slave | input worker | pty master >> | | >> | | n_tty_read() >> pty_write() | | input avail? no >> add data | | sleep >> schedule worker --->| | . >> |---> flush_to_ldisc() | . >> pty_close() | fill read buffer | . >> wait for worker | wakeup reader --->| . >> | read buffer full? |---> input avail ? yes >> |<--- yes - exit worker | copy 4096 bytes to user >> TTY_OTHER_CLOSED <---| |<--- kick worker >> | | >> >> **** New read() before worker starts **** >> >> | | n_tty_read() >> | | input avail? no >> | | TTY_OTHER_CLOSED? yes >> | | return -EIO >> >> Several conditions are required to trigger this race: >> 1. the ldisc read buffer must become full so the input worker exits >> 2. the read() count parameter must be >= 4096 so the ldisc read buffer >> is empty >> 3. the subsequent read() occurs before the kicked worker has processed >> more input >> >> However, the underlying cause of the race is that data is pipelined, while >> tty state is not; ie., data already written by the pty slave end is not >> yet visible to the pty master end, but state changes by the pty slave end >> are visible to the pty master end immediately. >> >> Pipeline the TTY_OTHER_CLOSED state through input worker to the reader. >> 1. Introduce TTY_OTHER_DONE which is set by the input worker when >> TTY_OTHER_CLOSED is set and either the input buffers are flushed or >> input processing has completed. Readers/polls are woken when >> TTY_OTHER_DONE is set. >> 2. Reader/poll checks TTY_OTHER_DONE instead of TTY_OTHER_CLOSED. >> 3. A new input worker is started from pty_close() after setting >> TTY_OTHER_CLOSED, which ensures the TTY_OTHER_DONE state will be >> set if the last input worker is already finished (or just about to >> exit). >> >> Remove tty_flush_to_ldisc(); no in-tree callers. >> >> Fixes: 52bce7f8d4fc ("pty, n_tty: Simplify input processing on final close") >> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=96311 >> BugLink: http://bugs.launchpad.net/bugs/1429756 >> Cc: <stable@vger.kernel.org> # 3.19+ >> Reported-by: Andy Whitcroft <apw@canonical.com> >> Reported-by: H.J. Lu <hjl.tools@gmail.com> >> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> >> --- >> Documentation/serial/tty.txt | 3 +++ >> drivers/tty/n_hdlc.c | 4 ++-- >> drivers/tty/n_tty.c | 4 ++-- >> drivers/tty/pty.c | 3 +-- >> drivers/tty/tty_buffer.c | 25 +++++++++++-------------- >> include/linux/tty.h | 2 +- >> 6 files changed, 20 insertions(+), 21 deletions(-) >> > > I tried it on 3.19.3 and it doesn't work with the testcase in > > https://bugzilla.kernel.org/show_bug.cgi?id=96311 Can you test this patch on top of mainline? There's a couple of fixes in 4.0-rc that specifically address weakly-ordered CPUs. Regards, Peter Hurley ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] pty: Fix input race when closing 2015-04-09 17:53 ` Peter Hurley @ 2015-04-09 17:55 ` H.J. Lu 2015-04-09 22:11 ` H.J. Lu 1 sibling, 0 replies; 5+ messages in thread From: H.J. Lu @ 2015-04-09 17:55 UTC (permalink / raw) To: Peter Hurley Cc: Greg Kroah-Hartman, Jiri Slaby, LKML, Alan Cox, Andy Whitcroft, Josh Boyer, stable On Thu, Apr 9, 2015 at 10:53 AM, Peter Hurley <peter@hurleysoftware.com> wrote: > On 04/09/2015 01:43 PM, H.J. Lu wrote: >> On Thu, Apr 9, 2015 at 7:54 AM, Peter Hurley <peter@hurleysoftware.com> wrote: >>> A read() from a pty master may mistakenly indicate EOF (errno == -EIO) >>> after the pty slave has closed, even though input data remains to be read. >>> For example, >>> >>> pty slave | input worker | pty master >>> | | >>> | | n_tty_read() >>> pty_write() | | input avail? no >>> add data | | sleep >>> schedule worker --->| | . >>> |---> flush_to_ldisc() | . >>> pty_close() | fill read buffer | . >>> wait for worker | wakeup reader --->| . >>> | read buffer full? |---> input avail ? yes >>> |<--- yes - exit worker | copy 4096 bytes to user >>> TTY_OTHER_CLOSED <---| |<--- kick worker >>> | | >>> >>> **** New read() before worker starts **** >>> >>> | | n_tty_read() >>> | | input avail? no >>> | | TTY_OTHER_CLOSED? yes >>> | | return -EIO >>> >>> Several conditions are required to trigger this race: >>> 1. the ldisc read buffer must become full so the input worker exits >>> 2. the read() count parameter must be >= 4096 so the ldisc read buffer >>> is empty >>> 3. the subsequent read() occurs before the kicked worker has processed >>> more input >>> >>> However, the underlying cause of the race is that data is pipelined, while >>> tty state is not; ie., data already written by the pty slave end is not >>> yet visible to the pty master end, but state changes by the pty slave end >>> are visible to the pty master end immediately. >>> >>> Pipeline the TTY_OTHER_CLOSED state through input worker to the reader. >>> 1. Introduce TTY_OTHER_DONE which is set by the input worker when >>> TTY_OTHER_CLOSED is set and either the input buffers are flushed or >>> input processing has completed. Readers/polls are woken when >>> TTY_OTHER_DONE is set. >>> 2. Reader/poll checks TTY_OTHER_DONE instead of TTY_OTHER_CLOSED. >>> 3. A new input worker is started from pty_close() after setting >>> TTY_OTHER_CLOSED, which ensures the TTY_OTHER_DONE state will be >>> set if the last input worker is already finished (or just about to >>> exit). >>> >>> Remove tty_flush_to_ldisc(); no in-tree callers. >>> >>> Fixes: 52bce7f8d4fc ("pty, n_tty: Simplify input processing on final close") >>> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=96311 >>> BugLink: http://bugs.launchpad.net/bugs/1429756 >>> Cc: <stable@vger.kernel.org> # 3.19+ >>> Reported-by: Andy Whitcroft <apw@canonical.com> >>> Reported-by: H.J. Lu <hjl.tools@gmail.com> >>> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> >>> --- >>> Documentation/serial/tty.txt | 3 +++ >>> drivers/tty/n_hdlc.c | 4 ++-- >>> drivers/tty/n_tty.c | 4 ++-- >>> drivers/tty/pty.c | 3 +-- >>> drivers/tty/tty_buffer.c | 25 +++++++++++-------------- >>> include/linux/tty.h | 2 +- >>> 6 files changed, 20 insertions(+), 21 deletions(-) >>> >> >> I tried it on 3.19.3 and it doesn't work with the testcase in >> >> https://bugzilla.kernel.org/show_bug.cgi?id=96311 > > Can you test this patch on top of mainline? There's a couple of > fixes in 4.0-rc that specifically address weakly-ordered CPUs. > I will give it a try. -- H.J. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] pty: Fix input race when closing 2015-04-09 17:53 ` Peter Hurley 2015-04-09 17:55 ` H.J. Lu @ 2015-04-09 22:11 ` H.J. Lu 1 sibling, 0 replies; 5+ messages in thread From: H.J. Lu @ 2015-04-09 22:11 UTC (permalink / raw) To: Peter Hurley Cc: Greg Kroah-Hartman, Jiri Slaby, LKML, Alan Cox, Andy Whitcroft, Josh Boyer, stable On Thu, Apr 9, 2015 at 10:53 AM, Peter Hurley <peter@hurleysoftware.com> wrote: > On 04/09/2015 01:43 PM, H.J. Lu wrote: >> On Thu, Apr 9, 2015 at 7:54 AM, Peter Hurley <peter@hurleysoftware.com> wrote: >>> A read() from a pty master may mistakenly indicate EOF (errno == -EIO) >>> after the pty slave has closed, even though input data remains to be read. >>> For example, >>> >>> pty slave | input worker | pty master >>> | | >>> | | n_tty_read() >>> pty_write() | | input avail? no >>> add data | | sleep >>> schedule worker --->| | . >>> |---> flush_to_ldisc() | . >>> pty_close() | fill read buffer | . >>> wait for worker | wakeup reader --->| . >>> | read buffer full? |---> input avail ? yes >>> |<--- yes - exit worker | copy 4096 bytes to user >>> TTY_OTHER_CLOSED <---| |<--- kick worker >>> | | >>> >>> **** New read() before worker starts **** >>> >>> | | n_tty_read() >>> | | input avail? no >>> | | TTY_OTHER_CLOSED? yes >>> | | return -EIO >>> >>> Several conditions are required to trigger this race: >>> 1. the ldisc read buffer must become full so the input worker exits >>> 2. the read() count parameter must be >= 4096 so the ldisc read buffer >>> is empty >>> 3. the subsequent read() occurs before the kicked worker has processed >>> more input >>> >>> However, the underlying cause of the race is that data is pipelined, while >>> tty state is not; ie., data already written by the pty slave end is not >>> yet visible to the pty master end, but state changes by the pty slave end >>> are visible to the pty master end immediately. >>> >>> Pipeline the TTY_OTHER_CLOSED state through input worker to the reader. >>> 1. Introduce TTY_OTHER_DONE which is set by the input worker when >>> TTY_OTHER_CLOSED is set and either the input buffers are flushed or >>> input processing has completed. Readers/polls are woken when >>> TTY_OTHER_DONE is set. >>> 2. Reader/poll checks TTY_OTHER_DONE instead of TTY_OTHER_CLOSED. >>> 3. A new input worker is started from pty_close() after setting >>> TTY_OTHER_CLOSED, which ensures the TTY_OTHER_DONE state will be >>> set if the last input worker is already finished (or just about to >>> exit). >>> >>> Remove tty_flush_to_ldisc(); no in-tree callers. >>> >>> Fixes: 52bce7f8d4fc ("pty, n_tty: Simplify input processing on final close") >>> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=96311 >>> BugLink: http://bugs.launchpad.net/bugs/1429756 >>> Cc: <stable@vger.kernel.org> # 3.19+ >>> Reported-by: Andy Whitcroft <apw@canonical.com> >>> Reported-by: H.J. Lu <hjl.tools@gmail.com> >>> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> >>> --- >>> Documentation/serial/tty.txt | 3 +++ >>> drivers/tty/n_hdlc.c | 4 ++-- >>> drivers/tty/n_tty.c | 4 ++-- >>> drivers/tty/pty.c | 3 +-- >>> drivers/tty/tty_buffer.c | 25 +++++++++++-------------- >>> include/linux/tty.h | 2 +- >>> 6 files changed, 20 insertions(+), 21 deletions(-) >>> >> >> I tried it on 3.19.3 and it doesn't work with the testcase in >> >> https://bugzilla.kernel.org/show_bug.cgi?id=96311 > > Can you test this patch on top of mainline? There's a couple of > fixes in 4.0-rc that specifically address weakly-ordered CPUs. I tried it on 4.0.0-rc7 and it doesn't work. -- H.J. ^ permalink raw reply [flat|nested] 5+ messages in thread
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2015-04-09 14:54 ` [PATCH] pty: Fix input race when closing Peter Hurley
2015-04-09 17:43 ` H.J. Lu
2015-04-09 17:53 ` Peter Hurley
2015-04-09 17:55 ` H.J. Lu
2015-04-09 22:11 ` H.J. Lu
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