[PATCH 0/3] Console preparatory work

[PATCH 0/3] Console preparatory work

[Alan Cox]

Preparatory locking clean up and tty_port work for the console.
---

Alan Cox (3):
      tty: Move the vt_tty field from the vc_data into the standard tty_port
      tty: Make vt's have a tty_port
      vc: Locking clean up


 drivers/char/keyboard.c        |   10 +++++-----
 drivers/char/selection.c       |    4 ++++
 drivers/char/vt.c              |   19 +++++++++++--------
 drivers/char/vt_ioctl.c        |    2 +-
 include/linux/console_struct.h |    3 ++-
 5 files changed, 23 insertions(+), 15 deletions(-)

-- 
Signature|No Signature

[PATCH 1/3] vc: Locking clean up

[Alan Cox]

The virtual console layer uses the BKL for various things that don't really
need it. Clean them out. Someone really needs to relock selection.c in its
entirity. Have fun...

Signed-off-by: Alan Cox <alan@linux.intel.com>
---

 drivers/char/selection.c |    4 ++++
 drivers/char/vt.c        |    7 ++++---
 2 files changed, 8 insertions(+), 3 deletions(-)


diff --git a/drivers/char/selection.c b/drivers/char/selection.c
index f97b9e8..6e79340 100644
--- a/drivers/char/selection.c
+++ b/drivers/char/selection.c
@@ -26,6 +26,7 @@
 #include <linux/selection.h>
 #include <linux/tiocl.h>
 #include <linux/console.h>
+#include <linux/smp_lock.h>
 
 /* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
 #define isspace(c)	((c) == ' ')
@@ -312,6 +313,8 @@ int paste_selection(struct tty_struct *tty)
 	struct  tty_ldisc *ld;
 	DECLARE_WAITQUEUE(wait, current);
 
+	lock_kernel();
+
 	acquire_console_sem();
 	poke_blanked_console();
 	release_console_sem();
@@ -335,5 +338,6 @@ int paste_selection(struct tty_struct *tty)
 	__set_current_state(TASK_RUNNING);
 
 	tty_ldisc_deref(ld);
+	unlock_kernel();
 	return 0;
 }
diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index bd1d116..c5e30e3 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -280,8 +280,12 @@ static inline unsigned short *screenpos(struct vc_data *vc, int offset, int view
 	return p;
 }
 
+/* Called  from the keyboard irq path.. */
 static inline void scrolldelta(int lines)
 {
+	/* FIXME */
+	/* scrolldelta needs some kind of consistency lock, but the BKL was
+	   and still is not protecting versus the scheduled back end */
 	scrollback_delta += lines;
 	schedule_console_callback();
 }
@@ -2604,8 +2608,6 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
 		return -EFAULT;
 	ret = 0;
 
-	lock_kernel();
-
 	switch (type)
 	{
 		case TIOCL_SETSEL:
@@ -2680,7 +2682,6 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
 			ret = -EINVAL;
 			break;
 	}
-	unlock_kernel();
 	return ret;
 }
 

[PATCH 2/3] tty: Make vt's have a tty_port

[Alan Cox]

The vt layer isn't safely handling reference counts to tty object on the input
side. Add a tty port structure to the vt layer in order to implement this using
the standard helpers.

Signed-off-by: Alan Cox <alan@linux.intel.com>
---

 drivers/char/vt.c              |    2 ++
 include/linux/console_struct.h |    2 ++
 2 files changed, 4 insertions(+), 0 deletions(-)


diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index c5e30e3..e5269cc 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -772,6 +772,7 @@ int vc_allocate(unsigned int currcons)	/* return 0 on success */
 	    if (!vc)
 		return -ENOMEM;
 	    vc_cons[currcons].d = vc;
+	    tty_port_init(&vc->port);
 	    INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
 	    visual_init(vc, currcons, 1);
 	    if (!*vc->vc_uni_pagedir_loc)
@@ -2909,6 +2910,7 @@ static int __init con_init(void)
 	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
 		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
+		tty_port_init(&vc->port);
 		visual_init(vc, currcons, 1);
 		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
 		vc_init(vc, vc->vc_rows, vc->vc_cols,
diff --git a/include/linux/console_struct.h b/include/linux/console_struct.h
index 38fe59d..57e83f1 100644
--- a/include/linux/console_struct.h
+++ b/include/linux/console_struct.h
@@ -21,6 +21,8 @@ struct vt_struct;
 #define NPAR 16
 
 struct vc_data {
+	struct tty_port port;			/* Upper level data */
+
 	unsigned short	vc_num;			/* Console number */
 	unsigned int	vc_cols;		/* [#] Console size */
 	unsigned int	vc_rows;

[PATCH 3/3] tty: Move the vt_tty field from the vc_data into the standard tty_port

[Alan Cox]

This takes all the tty references through the expected interface points so
we can refcount them.

Signed-off-by: Alan Cox <alan@linux.intel.com>
---

 drivers/char/keyboard.c        |   10 +++++-----
 drivers/char/vt.c              |   10 +++++-----
 drivers/char/vt_ioctl.c        |    2 +-
 include/linux/console_struct.h |    1 -
 4 files changed, 11 insertions(+), 12 deletions(-)


diff --git a/drivers/char/keyboard.c b/drivers/char/keyboard.c
index 54109dc..ec733f1 100644
--- a/drivers/char/keyboard.c
+++ b/drivers/char/keyboard.c
@@ -299,7 +299,7 @@ int kbd_rate(struct kbd_repeat *rep)
  */
 static void put_queue(struct vc_data *vc, int ch)
 {
-	struct tty_struct *tty = vc->vc_tty;
+	struct tty_struct *tty = vc->port.tty;
 
 	if (tty) {
 		tty_insert_flip_char(tty, ch, 0);
@@ -309,7 +309,7 @@ static void put_queue(struct vc_data *vc, int ch)
 
 static void puts_queue(struct vc_data *vc, char *cp)
 {
-	struct tty_struct *tty = vc->vc_tty;
+	struct tty_struct *tty = vc->port.tty;
 
 	if (!tty)
 		return;
@@ -485,7 +485,7 @@ static void fn_show_ptregs(struct vc_data *vc)
 
 static void fn_hold(struct vc_data *vc)
 {
-	struct tty_struct *tty = vc->vc_tty;
+	struct tty_struct *tty = vc->port.tty;
 
 	if (rep || !tty)
 		return;
@@ -563,7 +563,7 @@ static void fn_inc_console(struct vc_data *vc)
 
 static void fn_send_intr(struct vc_data *vc)
 {
-	struct tty_struct *tty = vc->vc_tty;
+	struct tty_struct *tty = vc->port.tty;
 
 	if (!tty)
 		return;
@@ -1162,7 +1162,7 @@ static void kbd_keycode(unsigned int keycode, int down, int hw_raw)
 	struct keyboard_notifier_param param = { .vc = vc, .value = keycode, .down = down };
 	int rc;
 
-	tty = vc->vc_tty;
+	tty = vc->port.tty;
 
 	if (tty && (!tty->driver_data)) {
 		/* No driver data? Strange. Okay we fix it then. */
diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index e5269cc..2ba720f 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -961,12 +961,12 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
  *	Resize a virtual console as seen from the console end of things. We
  *	use the common vc_do_resize methods to update the structures. The
  *	caller must hold the console sem to protect console internals and
- *	vc->vc_tty
+ *	vc->port.tty
  */
 
 int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
 {
-	return vc_do_resize(vc->vc_tty, vc, cols, rows);
+	return vc_do_resize(vc->port.tty, vc, cols, rows);
 }
 
 /**
@@ -2795,12 +2795,12 @@ static int con_open(struct tty_struct *tty, struct file *filp)
 			struct vc_data *vc = vc_cons[currcons].d;
 
 			/* Still being freed */
-			if (vc->vc_tty) {
+			if (vc->port.tty) {
 				release_console_sem();
 				return -ERESTARTSYS;
 			}
 			tty->driver_data = vc;
-			vc->vc_tty = tty;
+			vc->port.tty = tty;
 
 			if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
 				tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
@@ -2828,7 +2828,7 @@ static void con_shutdown(struct tty_struct *tty)
 	struct vc_data *vc = tty->driver_data;
 	BUG_ON(vc == NULL);
 	acquire_console_sem();
-	vc->vc_tty = NULL;
+	vc->port.tty = NULL;
 	release_console_sem();
 	tty_shutdown(tty);
 }
diff --git a/drivers/char/vt_ioctl.c b/drivers/char/vt_ioctl.c
index 6aa1028..625f77d 100644
--- a/drivers/char/vt_ioctl.c
+++ b/drivers/char/vt_ioctl.c
@@ -1367,7 +1367,7 @@ void vc_SAK(struct work_struct *work)
 	acquire_console_sem();
 	vc = vc_con->d;
 	if (vc) {
-		tty = vc->vc_tty;
+		tty = vc->port.tty;
 		/*
 		 * SAK should also work in all raw modes and reset
 		 * them properly.
diff --git a/include/linux/console_struct.h b/include/linux/console_struct.h
index 57e83f1..3364898 100644
--- a/include/linux/console_struct.h
+++ b/include/linux/console_struct.h
@@ -58,7 +58,6 @@ struct vc_data {
 	/* VT terminal data */
 	unsigned int	vc_state;		/* Escape sequence parser state */
 	unsigned int	vc_npar,vc_par[NPAR];	/* Parameters of current escape sequence */
-	struct tty_struct *vc_tty;		/* TTY we are attached to */
 	/* data for manual vt switching */
 	struct vt_mode	vt_mode;
 	struct pid 	*vt_pid;