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Date: Fri, 8 Jan 2010 12:00:23 +0100
From: Jan Kiszka <jan.kiszka@....de>
To: David Miller <davem@...emloft.net>,
Karsten Keil <isdn@...ux-pingi.de>
Cc: linux-kernel@...r.kernel.org, i4ldeveloper@...tserv.isdn4linux.de,
isdn4linux@...tserv.isdn4linux.de, netdev@...r.kernel.org
Subject: [PATCH 21/31] CAPI: Remove useless checks for tty->driver_data or hung up state
Remove more desperate attempts to fix races in the original code: As
long as the TTY is open, its driver_data cannot become NULL. And we
already call tty_hangup to signal the end of a connection, no need to
check for mp->nccip in addition.
Signed-off-by: Jan Kiszka <jan.kiszka@....de>
---
drivers/isdn/capi/capi.c | 80 ++++++++++++----------------------------------
1 files changed, 21 insertions(+), 59 deletions(-)
diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index 7710a66..77faa4e 100644
--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -1017,7 +1017,7 @@ static void capinc_tty_close(struct tty_struct * tty, struct file * file)
static int capinc_tty_write(struct tty_struct * tty,
const unsigned char *buf, int count)
{
- struct capiminor *mp = (struct capiminor *)tty->driver_data;
+ struct capiminor *mp = tty->driver_data;
struct sk_buff *skb;
unsigned long flags;
@@ -1025,13 +1025,6 @@ static int capinc_tty_write(struct tty_struct * tty,
printk(KERN_DEBUG "capinc_tty_write(count=%d)n", count);
#endif
- if (!mp || !mp->nccip) {
-#ifdef _DEBUG_TTYFUNCS
- printk(KERN_DEBUG "capinc_tty_write: mp or mp->ncci NULLn");
-#endif
- return 0;
- }
-
spin_lock_irqsave(&workaround_lock, flags);
skb = mp->ttyskb;
if (skb) {
@@ -1060,7 +1053,7 @@ static int capinc_tty_write(struct tty_struct * tty,
static int capinc_tty_put_char(struct tty_struct *tty, unsigned char ch)
{
- struct capiminor *mp = (struct capiminor *)tty->driver_data;
+ struct capiminor *mp = tty->driver_data;
struct sk_buff *skb;
unsigned long flags;
int ret = 1;
@@ -1069,13 +1062,6 @@ static int capinc_tty_put_char(struct tty_struct *tty, unsigned char ch)
printk(KERN_DEBUG "capinc_put_char(%u)n", ch);
#endif
- if (!mp || !mp->nccip) {
-#ifdef _DEBUG_TTYFUNCS
- printk(KERN_DEBUG "capinc_tty_put_char: mp or mp->ncci NULLn");
-#endif
- return 0;
- }
-
spin_lock_irqsave(&workaround_lock, flags);
skb = mp->ttyskb;
if (skb) {
@@ -1104,7 +1090,7 @@ static int capinc_tty_put_char(struct tty_struct *tty, unsigned char ch)
static void capinc_tty_flush_chars(struct tty_struct *tty)
{
- struct capiminor *mp = (struct capiminor *)tty->driver_data;
+ struct capiminor *mp = tty->driver_data;
struct sk_buff *skb;
unsigned long flags;
@@ -1112,13 +1098,6 @@ static void capinc_tty_flush_chars(struct tty_struct *tty)
printk(KERN_DEBUG "capinc_tty_flush_charsn");
#endif
- if (!mp || !mp->nccip) {
-#ifdef _DEBUG_TTYFUNCS
- printk(KERN_DEBUG "capinc_tty_flush_chars: mp or mp->ncci NULLn");
-#endif
- return;
- }
-
spin_lock_irqsave(&workaround_lock, flags);
skb = mp->ttyskb;
if (skb) {
@@ -1133,14 +1112,9 @@ static void capinc_tty_flush_chars(struct tty_struct *tty)
static int capinc_tty_write_room(struct tty_struct *tty)
{
- struct capiminor *mp = (struct capiminor *)tty->driver_data;
+ struct capiminor *mp = tty->driver_data;
int room;
- if (!mp || !mp->nccip) {
-#ifdef _DEBUG_TTYFUNCS
- printk(KERN_DEBUG "capinc_tty_write_room: mp or mp->ncci NULLn");
-#endif
- return 0;
- }
+
room = CAPINC_MAX_SENDQUEUE-skb_queue_len(&mp->outqueue);
room *= CAPI_MAX_BLKSIZE;
#ifdef _DEBUG_TTYFUNCS
@@ -1151,13 +1125,8 @@ static int capinc_tty_write_room(struct tty_struct *tty)
static int capinc_tty_chars_in_buffer(struct tty_struct *tty)
{
- struct capiminor *mp = (struct capiminor *)tty->driver_data;
- if (!mp || !mp->nccip) {
-#ifdef _DEBUG_TTYFUNCS
- printk(KERN_DEBUG "capinc_tty_chars_in_buffer: mp or mp->ncci NULLn");
-#endif
- return 0;
- }
+ struct capiminor *mp = tty->driver_data;
+
#ifdef _DEBUG_TTYFUNCS
printk(KERN_DEBUG "capinc_tty_chars_in_buffer = %d nack=%d sq=%d rq=%dn",
mp->outbytes, mp->nack,
@@ -1188,53 +1157,46 @@ static void capinc_tty_set_termios(struct tty_struct *tty, struct ktermios * old
static void capinc_tty_throttle(struct tty_struct * tty)
{
- struct capiminor *mp = (struct capiminor *)tty->driver_data;
+ struct capiminor *mp = tty->driver_data;
#ifdef _DEBUG_TTYFUNCS
printk(KERN_DEBUG "capinc_tty_throttlen");
#endif
- if (mp)
- mp->ttyinstop = 1;
+ mp->ttyinstop = 1;
}
static void capinc_tty_unthrottle(struct tty_struct * tty)
{
- struct capiminor *mp = (struct capiminor *)tty->driver_data;
+ struct capiminor *mp = tty->driver_data;
unsigned long flags;
#ifdef _DEBUG_TTYFUNCS
printk(KERN_DEBUG "capinc_tty_unthrottlen");
#endif
- if (mp) {
- spin_lock_irqsave(&workaround_lock, flags);
- mp->ttyinstop = 0;
- handle_minor_recv(mp);
- spin_unlock_irqrestore(&workaround_lock, flags);
- }
+ spin_lock_irqsave(&workaround_lock, flags);
+ mp->ttyinstop = 0;
+ handle_minor_recv(mp);
+ spin_unlock_irqrestore(&workaround_lock, flags);
}
static void capinc_tty_stop(struct tty_struct *tty)
{
- struct capiminor *mp = (struct capiminor *)tty->driver_data;
+ struct capiminor *mp = tty->driver_data;
#ifdef _DEBUG_TTYFUNCS
printk(KERN_DEBUG "capinc_tty_stopn");
#endif
- if (mp) {
- mp->ttyoutstop = 1;
- }
+ mp->ttyoutstop = 1;
}
static void capinc_tty_start(struct tty_struct *tty)
{
- struct capiminor *mp = (struct capiminor *)tty->driver_data;
+ struct capiminor *mp = tty->driver_data;
unsigned long flags;
#ifdef _DEBUG_TTYFUNCS
printk(KERN_DEBUG "capinc_tty_startn");
#endif
- if (mp) {
- spin_lock_irqsave(&workaround_lock, flags);
- mp->ttyoutstop = 0;
- (void)handle_minor_send(mp);
- spin_unlock_irqrestore(&workaround_lock, flags);
- }
+ spin_lock_irqsave(&workaround_lock, flags);
+ mp->ttyoutstop = 0;
+ (void)handle_minor_send(mp);
+ spin_unlock_irqrestore(&workaround_lock, flags);
}
static void capinc_tty_hangup(struct tty_struct *tty)
--
1.6.0.2
--
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