* [PATCH v2] tty: hold lock across tty buffer finding and buffer filling
@ 2012-03-16 3:00 Tu, Xiaobing
2012-03-16 20:14 ` gregkh
0 siblings, 1 reply; 6+ messages in thread
From: Tu, Xiaobing @ 2012-03-16 3:00 UTC (permalink / raw)
To: gregkh@linuxfoundation.org
Cc: alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org,
Zhang, Yanmin, Du, Alek, Zuo, Jiao
From: Xiaobing Tu <xiaobing.tu@intel.com>
tty_buffer_request_room is well protected, but while after it returns,
it releases the port->lock. tty->buf.tail might be modified
by either irq handler or other threads. The patch adds more protection
by holding the lock across tty buffer finding and buffer filling.
Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Xiaobing Tu <xiaobing.tu@intel.com>
---
drivers/tty/tty_buffer.c | 85 +++++++++++++++++++++++++++++++++++-----------
1 files changed, 65 insertions(+), 20 deletions(-)
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 6c9b7cd..91e326f 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -185,25 +185,19 @@ static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size)
/* Should possibly check if this fails for the largest buffer we
have queued and recycle that ? */
}
-
/**
- * tty_buffer_request_room - grow tty buffer if needed
+ * __tty_buffer_request_room - grow tty buffer if needed
* @tty: tty structure
* @size: size desired
*
* Make at least size bytes of linear space available for the tty
* buffer. If we fail return the size we managed to find.
- *
- * Locking: Takes tty->buf.lock
+ * Locking: Caller must hold tty->buf.lock
*/
-int tty_buffer_request_room(struct tty_struct *tty, size_t size)
+static int __tty_buffer_request_room(struct tty_struct *tty, size_t size)
{
struct tty_buffer *b, *n;
int left;
- unsigned long flags;
-
- spin_lock_irqsave(&tty->buf.lock, flags);
-
/* OPTIMISATION: We could keep a per tty "zero" sized buffer to
remove this conditional if its worth it. This would be invisible
to the callers */
@@ -225,9 +219,30 @@ int tty_buffer_request_room(struct tty_struct *tty, size_t size)
size = left;
}
- spin_unlock_irqrestore(&tty->buf.lock, flags);
return size;
}
+
+
+/**
+ * tty_buffer_request_room - grow tty buffer if needed
+ * @tty: tty structure
+ * @size: size desired
+ *
+ * Make at least size bytes of linear space available for the tty
+ * buffer. If we fail return the size we managed to find.
+ *
+ * Locking: Takes tty->buf.lock
+ */
+int tty_buffer_request_room(struct tty_struct *tty, size_t size)
+{
+ unsigned long flags;
+ int length;
+
+ spin_lock_irqsave(&tty->buf.lock, flags);
+ length = __tty_buffer_request_room(tty, size);
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+ return length;
+}
EXPORT_SYMBOL_GPL(tty_buffer_request_room);
/**
@@ -249,14 +264,22 @@ int tty_insert_flip_string_fixed_flag(struct tty_struct *tty,
int copied = 0;
do {
int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
- int space = tty_buffer_request_room(tty, goal);
- struct tty_buffer *tb = tty->buf.tail;
+ int space;
+ unsigned long flags;
+ struct tty_buffer *tb;
+
+ spin_lock_irqsave(&tty->buf.lock, flags);
+ space = __tty_buffer_request_room(tty, goal);
+ tb = tty->buf.tail;
/* If there is no space then tb may be NULL */
- if (unlikely(space == 0))
+ if (unlikely(space == 0)) {
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
break;
+ }
memcpy(tb->char_buf_ptr + tb->used, chars, space);
memset(tb->flag_buf_ptr + tb->used, flag, space);
tb->used += space;
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
copied += space;
chars += space;
/* There is a small chance that we need to split the data over
@@ -286,14 +309,22 @@ int tty_insert_flip_string_flags(struct tty_struct *tty,
int copied = 0;
do {
int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
- int space = tty_buffer_request_room(tty, goal);
- struct tty_buffer *tb = tty->buf.tail;
+ int space;
+ unsigned long __flags;
+ struct tty_buffer *tb;
+
+ spin_lock_irqsave(&tty->buf.lock, __flags);
+ space = __tty_buffer_request_room(tty, goal);
+ tb = tty->buf.tail;
/* If there is no space then tb may be NULL */
- if (unlikely(space == 0))
+ if (unlikely(space == 0)) {
+ spin_unlock_irqrestore(&tty->buf.lock, __flags);
break;
+ }
memcpy(tb->char_buf_ptr + tb->used, chars, space);
memcpy(tb->flag_buf_ptr + tb->used, flags, space);
tb->used += space;
+ spin_unlock_irqrestore(&tty->buf.lock, __flags);
copied += space;
chars += space;
flags += space;
@@ -344,13 +375,20 @@ EXPORT_SYMBOL(tty_schedule_flip);
int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars,
size_t size)
{
- int space = tty_buffer_request_room(tty, size);
+ int space;
+ unsigned long flags;
+ struct tty_buffer *tb;
+
+ spin_lock_irqsave(&tty->buf.lock, flags);
+ space = __tty_buffer_request_room(tty, size);
+
+ tb = tty->buf.tail;
if (likely(space)) {
- struct tty_buffer *tb = tty->buf.tail;
*chars = tb->char_buf_ptr + tb->used;
memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
tb->used += space;
}
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
return space;
}
EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
@@ -374,13 +412,20 @@ EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
int tty_prepare_flip_string_flags(struct tty_struct *tty,
unsigned char **chars, char **flags, size_t size)
{
- int space = tty_buffer_request_room(tty, size);
+ int space;
+ unsigned long __flags;
+ struct tty_buffer *tb;
+
+ spin_lock_irqsave(&tty->buf.lock, __flags);
+ space = __tty_buffer_request_room(tty, size);
+
+ tb = tty->buf.tail;
if (likely(space)) {
- struct tty_buffer *tb = tty->buf.tail;
*chars = tb->char_buf_ptr + tb->used;
*flags = tb->flag_buf_ptr + tb->used;
tb->used += space;
}
+ spin_unlock_irqrestore(&tty->buf.lock, __flags);
return space;
}
EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags);
--
1.7.4.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2] tty: hold lock across tty buffer finding and buffer filling
2012-03-16 3:00 [PATCH v2] tty: hold lock across tty buffer finding and buffer filling Tu, Xiaobing
@ 2012-03-16 20:14 ` gregkh
2012-03-16 21:01 ` Jiri Slaby
2012-03-30 10:26 ` Tu, Xiaobing
0 siblings, 2 replies; 6+ messages in thread
From: gregkh @ 2012-03-16 20:14 UTC (permalink / raw)
To: Tu, Xiaobing, Jiri Slaby
Cc: alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org,
Zhang, Yanmin, Du, Alek, Zuo, Jiao
Jiri,
Do you have any objections to me applying the patch below?
thanks,
greg k-h
On Fri, Mar 16, 2012 at 03:00:26AM +0000, Tu, Xiaobing wrote:
> From: Xiaobing Tu <xiaobing.tu@intel.com>
>
> tty_buffer_request_room is well protected, but while after it returns,
> it releases the port->lock. tty->buf.tail might be modified
> by either irq handler or other threads. The patch adds more protection
> by holding the lock across tty buffer finding and buffer filling.
> Signed-off-by: Alek Du <alek.du@intel.com>
> Signed-off-by: Xiaobing Tu <xiaobing.tu@intel.com>
> ---
> drivers/tty/tty_buffer.c | 85 +++++++++++++++++++++++++++++++++++-----------
> 1 files changed, 65 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
> index 6c9b7cd..91e326f 100644
> --- a/drivers/tty/tty_buffer.c
> +++ b/drivers/tty/tty_buffer.c
> @@ -185,25 +185,19 @@ static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size)
> /* Should possibly check if this fails for the largest buffer we
> have queued and recycle that ? */
> }
> -
> /**
> - * tty_buffer_request_room - grow tty buffer if needed
> + * __tty_buffer_request_room - grow tty buffer if needed
> * @tty: tty structure
> * @size: size desired
> *
> * Make at least size bytes of linear space available for the tty
> * buffer. If we fail return the size we managed to find.
> - *
> - * Locking: Takes tty->buf.lock
> + * Locking: Caller must hold tty->buf.lock
> */
> -int tty_buffer_request_room(struct tty_struct *tty, size_t size)
> +static int __tty_buffer_request_room(struct tty_struct *tty, size_t size)
> {
> struct tty_buffer *b, *n;
> int left;
> - unsigned long flags;
> -
> - spin_lock_irqsave(&tty->buf.lock, flags);
> -
> /* OPTIMISATION: We could keep a per tty "zero" sized buffer to
> remove this conditional if its worth it. This would be invisible
> to the callers */
> @@ -225,9 +219,30 @@ int tty_buffer_request_room(struct tty_struct *tty, size_t size)
> size = left;
> }
>
> - spin_unlock_irqrestore(&tty->buf.lock, flags);
> return size;
> }
> +
> +
> +/**
> + * tty_buffer_request_room - grow tty buffer if needed
> + * @tty: tty structure
> + * @size: size desired
> + *
> + * Make at least size bytes of linear space available for the tty
> + * buffer. If we fail return the size we managed to find.
> + *
> + * Locking: Takes tty->buf.lock
> + */
> +int tty_buffer_request_room(struct tty_struct *tty, size_t size)
> +{
> + unsigned long flags;
> + int length;
> +
> + spin_lock_irqsave(&tty->buf.lock, flags);
> + length = __tty_buffer_request_room(tty, size);
> + spin_unlock_irqrestore(&tty->buf.lock, flags);
> + return length;
> +}
> EXPORT_SYMBOL_GPL(tty_buffer_request_room);
>
> /**
> @@ -249,14 +264,22 @@ int tty_insert_flip_string_fixed_flag(struct tty_struct *tty,
> int copied = 0;
> do {
> int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
> - int space = tty_buffer_request_room(tty, goal);
> - struct tty_buffer *tb = tty->buf.tail;
> + int space;
> + unsigned long flags;
> + struct tty_buffer *tb;
> +
> + spin_lock_irqsave(&tty->buf.lock, flags);
> + space = __tty_buffer_request_room(tty, goal);
> + tb = tty->buf.tail;
> /* If there is no space then tb may be NULL */
> - if (unlikely(space == 0))
> + if (unlikely(space == 0)) {
> + spin_unlock_irqrestore(&tty->buf.lock, flags);
> break;
> + }
> memcpy(tb->char_buf_ptr + tb->used, chars, space);
> memset(tb->flag_buf_ptr + tb->used, flag, space);
> tb->used += space;
> + spin_unlock_irqrestore(&tty->buf.lock, flags);
> copied += space;
> chars += space;
> /* There is a small chance that we need to split the data over
> @@ -286,14 +309,22 @@ int tty_insert_flip_string_flags(struct tty_struct *tty,
> int copied = 0;
> do {
> int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
> - int space = tty_buffer_request_room(tty, goal);
> - struct tty_buffer *tb = tty->buf.tail;
> + int space;
> + unsigned long __flags;
> + struct tty_buffer *tb;
> +
> + spin_lock_irqsave(&tty->buf.lock, __flags);
> + space = __tty_buffer_request_room(tty, goal);
> + tb = tty->buf.tail;
> /* If there is no space then tb may be NULL */
> - if (unlikely(space == 0))
> + if (unlikely(space == 0)) {
> + spin_unlock_irqrestore(&tty->buf.lock, __flags);
> break;
> + }
> memcpy(tb->char_buf_ptr + tb->used, chars, space);
> memcpy(tb->flag_buf_ptr + tb->used, flags, space);
> tb->used += space;
> + spin_unlock_irqrestore(&tty->buf.lock, __flags);
> copied += space;
> chars += space;
> flags += space;
> @@ -344,13 +375,20 @@ EXPORT_SYMBOL(tty_schedule_flip);
> int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars,
> size_t size)
> {
> - int space = tty_buffer_request_room(tty, size);
> + int space;
> + unsigned long flags;
> + struct tty_buffer *tb;
> +
> + spin_lock_irqsave(&tty->buf.lock, flags);
> + space = __tty_buffer_request_room(tty, size);
> +
> + tb = tty->buf.tail;
> if (likely(space)) {
> - struct tty_buffer *tb = tty->buf.tail;
> *chars = tb->char_buf_ptr + tb->used;
> memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
> tb->used += space;
> }
> + spin_unlock_irqrestore(&tty->buf.lock, flags);
> return space;
> }
> EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
> @@ -374,13 +412,20 @@ EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
> int tty_prepare_flip_string_flags(struct tty_struct *tty,
> unsigned char **chars, char **flags, size_t size)
> {
> - int space = tty_buffer_request_room(tty, size);
> + int space;
> + unsigned long __flags;
> + struct tty_buffer *tb;
> +
> + spin_lock_irqsave(&tty->buf.lock, __flags);
> + space = __tty_buffer_request_room(tty, size);
> +
> + tb = tty->buf.tail;
> if (likely(space)) {
> - struct tty_buffer *tb = tty->buf.tail;
> *chars = tb->char_buf_ptr + tb->used;
> *flags = tb->flag_buf_ptr + tb->used;
> tb->used += space;
> }
> + spin_unlock_irqrestore(&tty->buf.lock, __flags);
> return space;
> }
> EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags);
> --
> 1.7.4.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] tty: hold lock across tty buffer finding and buffer filling
2012-03-16 20:14 ` gregkh
@ 2012-03-16 21:01 ` Jiri Slaby
2012-03-30 10:26 ` Tu, Xiaobing
1 sibling, 0 replies; 6+ messages in thread
From: Jiri Slaby @ 2012-03-16 21:01 UTC (permalink / raw)
To: gregkh@linuxfoundation.org
Cc: Tu, Xiaobing, alan@lxorguk.ukuu.org.uk,
linux-kernel@vger.kernel.org, Zhang, Yanmin, Du, Alek, Zuo, Jiao
On 03/16/2012 09:14 PM, gregkh@linuxfoundation.org wrote:
> Do you have any objections to me applying the patch below?
The only issue with the patch is that I'm not convinced it fixes
tty_prepare_flip_string* properly. I don't think it improves anything there.
thanks,
--
js
suse labs
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [PATCH v2] tty: hold lock across tty buffer finding and buffer filling
2012-03-16 20:14 ` gregkh
2012-03-16 21:01 ` Jiri Slaby
@ 2012-03-30 10:26 ` Tu, Xiaobing
2012-03-30 10:34 ` Alan Cox
2012-03-30 14:19 ` gregkh
1 sibling, 2 replies; 6+ messages in thread
From: Tu, Xiaobing @ 2012-03-30 10:26 UTC (permalink / raw)
To: gregkh@linuxfoundation.org, Jiri Slaby
Cc: alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org,
Zhang, Yanmin, Du, Alek, Zuo, Jiao
Hi Greg
Even there still a prepare buffer not protected, the patch is still good to protect rest case, so this patch is still "nice to have"
it makes the situation better. for the not-fixed case, we can have another patch to address that. Do you agree?
Br
Xiaobing
-----Original Message-----
From: gregkh@linuxfoundation.org [mailto:gregkh@linuxfoundation.org]
Sent: Saturday, March 17, 2012 4:15 AM
To: Tu, Xiaobing; Jiri Slaby
Cc: alan@lxorguk.ukuu.org.uk; linux-kernel@vger.kernel.org; Zhang, Yanmin; Du, Alek; Zuo, Jiao
Subject: Re: [PATCH v2] tty: hold lock across tty buffer finding and buffer filling
Jiri,
Do you have any objections to me applying the patch below?
thanks,
greg k-h
On Fri, Mar 16, 2012 at 03:00:26AM +0000, Tu, Xiaobing wrote:
> From: Xiaobing Tu <xiaobing.tu@intel.com>
>
> tty_buffer_request_room is well protected, but while after it returns,
> it releases the port->lock. tty->buf.tail might be modified by either
> irq handler or other threads. The patch adds more protection by
> holding the lock across tty buffer finding and buffer filling.
> Signed-off-by: Alek Du <alek.du@intel.com>
> Signed-off-by: Xiaobing Tu <xiaobing.tu@intel.com>
> ---
> drivers/tty/tty_buffer.c | 85 +++++++++++++++++++++++++++++++++++-----------
> 1 files changed, 65 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c index
> 6c9b7cd..91e326f 100644
> --- a/drivers/tty/tty_buffer.c
> +++ b/drivers/tty/tty_buffer.c
> @@ -185,25 +185,19 @@ static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size)
> /* Should possibly check if this fails for the largest buffer we
> have queued and recycle that ? */ }
> -
> /**
> - * tty_buffer_request_room - grow tty buffer if needed
> + * __tty_buffer_request_room - grow tty buffer if needed
> * @tty: tty structure
> * @size: size desired
> *
> * Make at least size bytes of linear space available for the tty
> * buffer. If we fail return the size we managed to find.
> - *
> - * Locking: Takes tty->buf.lock
> + * Locking: Caller must hold tty->buf.lock
> */
> -int tty_buffer_request_room(struct tty_struct *tty, size_t size)
> +static int __tty_buffer_request_room(struct tty_struct *tty, size_t
> +size)
> {
> struct tty_buffer *b, *n;
> int left;
> - unsigned long flags;
> -
> - spin_lock_irqsave(&tty->buf.lock, flags);
> -
> /* OPTIMISATION: We could keep a per tty "zero" sized buffer to
> remove this conditional if its worth it. This would be invisible
> to the callers */
> @@ -225,9 +219,30 @@ int tty_buffer_request_room(struct tty_struct *tty, size_t size)
> size = left;
> }
>
> - spin_unlock_irqrestore(&tty->buf.lock, flags);
> return size;
> }
> +
> +
> +/**
> + * tty_buffer_request_room - grow tty buffer if needed
> + * @tty: tty structure
> + * @size: size desired
> + *
> + * Make at least size bytes of linear space available for the tty
> + * buffer. If we fail return the size we managed to find.
> + *
> + * Locking: Takes tty->buf.lock
> + */
> +int tty_buffer_request_room(struct tty_struct *tty, size_t size) {
> + unsigned long flags;
> + int length;
> +
> + spin_lock_irqsave(&tty->buf.lock, flags);
> + length = __tty_buffer_request_room(tty, size);
> + spin_unlock_irqrestore(&tty->buf.lock, flags);
> + return length;
> +}
> EXPORT_SYMBOL_GPL(tty_buffer_request_room);
>
> /**
> @@ -249,14 +264,22 @@ int tty_insert_flip_string_fixed_flag(struct tty_struct *tty,
> int copied = 0;
> do {
> int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
> - int space = tty_buffer_request_room(tty, goal);
> - struct tty_buffer *tb = tty->buf.tail;
> + int space;
> + unsigned long flags;
> + struct tty_buffer *tb;
> +
> + spin_lock_irqsave(&tty->buf.lock, flags);
> + space = __tty_buffer_request_room(tty, goal);
> + tb = tty->buf.tail;
> /* If there is no space then tb may be NULL */
> - if (unlikely(space == 0))
> + if (unlikely(space == 0)) {
> + spin_unlock_irqrestore(&tty->buf.lock, flags);
> break;
> + }
> memcpy(tb->char_buf_ptr + tb->used, chars, space);
> memset(tb->flag_buf_ptr + tb->used, flag, space);
> tb->used += space;
> + spin_unlock_irqrestore(&tty->buf.lock, flags);
> copied += space;
> chars += space;
> /* There is a small chance that we need to split the data over @@
> -286,14 +309,22 @@ int tty_insert_flip_string_flags(struct tty_struct *tty,
> int copied = 0;
> do {
> int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
> - int space = tty_buffer_request_room(tty, goal);
> - struct tty_buffer *tb = tty->buf.tail;
> + int space;
> + unsigned long __flags;
> + struct tty_buffer *tb;
> +
> + spin_lock_irqsave(&tty->buf.lock, __flags);
> + space = __tty_buffer_request_room(tty, goal);
> + tb = tty->buf.tail;
> /* If there is no space then tb may be NULL */
> - if (unlikely(space == 0))
> + if (unlikely(space == 0)) {
> + spin_unlock_irqrestore(&tty->buf.lock, __flags);
> break;
> + }
> memcpy(tb->char_buf_ptr + tb->used, chars, space);
> memcpy(tb->flag_buf_ptr + tb->used, flags, space);
> tb->used += space;
> + spin_unlock_irqrestore(&tty->buf.lock, __flags);
> copied += space;
> chars += space;
> flags += space;
> @@ -344,13 +375,20 @@ EXPORT_SYMBOL(tty_schedule_flip); int
> tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars,
> size_t size)
> {
> - int space = tty_buffer_request_room(tty, size);
> + int space;
> + unsigned long flags;
> + struct tty_buffer *tb;
> +
> + spin_lock_irqsave(&tty->buf.lock, flags);
> + space = __tty_buffer_request_room(tty, size);
> +
> + tb = tty->buf.tail;
> if (likely(space)) {
> - struct tty_buffer *tb = tty->buf.tail;
> *chars = tb->char_buf_ptr + tb->used;
> memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
> tb->used += space;
> }
> + spin_unlock_irqrestore(&tty->buf.lock, flags);
> return space;
> }
> EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
> @@ -374,13 +412,20 @@ EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
> int tty_prepare_flip_string_flags(struct tty_struct *tty,
> unsigned char **chars, char **flags, size_t size) {
> - int space = tty_buffer_request_room(tty, size);
> + int space;
> + unsigned long __flags;
> + struct tty_buffer *tb;
> +
> + spin_lock_irqsave(&tty->buf.lock, __flags);
> + space = __tty_buffer_request_room(tty, size);
> +
> + tb = tty->buf.tail;
> if (likely(space)) {
> - struct tty_buffer *tb = tty->buf.tail;
> *chars = tb->char_buf_ptr + tb->used;
> *flags = tb->flag_buf_ptr + tb->used;
> tb->used += space;
> }
> + spin_unlock_irqrestore(&tty->buf.lock, __flags);
> return space;
> }
> EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags);
> --
> 1.7.4.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] tty: hold lock across tty buffer finding and buffer filling
2012-03-30 10:26 ` Tu, Xiaobing
@ 2012-03-30 10:34 ` Alan Cox
2012-03-30 14:19 ` gregkh
1 sibling, 0 replies; 6+ messages in thread
From: Alan Cox @ 2012-03-30 10:34 UTC (permalink / raw)
To: Tu, Xiaobing
Cc: gregkh@linuxfoundation.org, Jiri Slaby,
linux-kernel@vger.kernel.org, Zhang, Yanmin, Du, Alek, Zuo, Jiao
On Fri, 30 Mar 2012 10:26:27 +0000
"Tu, Xiaobing" <xiaobing.tu@intel.com> wrote:
> Hi Greg
> Even there still a prepare buffer not protected, the patch is still good to protect rest case, so this patch is still "nice to have"
> it makes the situation better. for the not-fixed case, we can have another patch to address that. Do you agree?
Can't speak for Greg (who I suspect is busy with the merge window to
Linus) but I think this is the right thing to do once the merge window is
over. The unfixed case needs other things to happen first, such as the
removal of tty_lock/tty_unlock. At that point much of this should become
much simpler.
Alan
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] tty: hold lock across tty buffer finding and buffer filling
2012-03-30 10:26 ` Tu, Xiaobing
2012-03-30 10:34 ` Alan Cox
@ 2012-03-30 14:19 ` gregkh
1 sibling, 0 replies; 6+ messages in thread
From: gregkh @ 2012-03-30 14:19 UTC (permalink / raw)
To: Tu, Xiaobing
Cc: Jiri Slaby, alan@lxorguk.ukuu.org.uk,
linux-kernel@vger.kernel.org, Zhang, Yanmin, Du, Alek, Zuo, Jiao
On Fri, Mar 30, 2012 at 10:26:27AM +0000, Tu, Xiaobing wrote:
> Hi Greg
> Even there still a prepare buffer not protected, the patch is still
> good to protect rest case, so this patch is still "nice to have" it
> makes the situation better. for the not-fixed case, we can have
> another patch to address that. Do you agree?
As Alan says, it's in the middle of the merge window right now, and I
can't take any new patches until 3.4-rc1 is out. It is in my queue to
review when the merge window is over.
patience please,
greg k-h
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-03-30 14:19 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-03-16 3:00 [PATCH v2] tty: hold lock across tty buffer finding and buffer filling Tu, Xiaobing
2012-03-16 20:14 ` gregkh
2012-03-16 21:01 ` Jiri Slaby
2012-03-30 10:26 ` Tu, Xiaobing
2012-03-30 10:34 ` Alan Cox
2012-03-30 14:19 ` gregkh
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