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From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: torvalds@linux-foundation.org, linux-kernel@vger.kernel.org
Subject: [PATCH 73/80] tty: Remove lots of NULL checks
Date: Mon, 13 Oct 2008 10:44:57 +0100	[thread overview]
Message-ID: <20081013094448.21645.54493.stgit@localhost.localdomain> (raw)
In-Reply-To: <20081013092758.21645.2359.stgit@localhost.localdomain>

From: Alan Cox <alan@redhat.com>

Many tty drivers contain 'can't happen' checks against NULL pointers passed
in by the tty layer. These have never been possible to occur. Even more
importantly if they ever do occur we want to know as it would be a serious
bug.

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

 drivers/char/amiserial.c      |    6 ------
 drivers/char/generic_serial.c |   21 ---------------------
 drivers/char/istallion.c      |    6 ------
 drivers/char/mxser.c          |    5 -----
 drivers/char/n_r3964.c        |    8 +-------
 drivers/char/stallion.c       |   34 ----------------------------------
 6 files changed, 1 insertions(+), 79 deletions(-)


diff --git a/drivers/char/amiserial.c b/drivers/char/amiserial.c
index 6e763e3..98821f9 100644
--- a/drivers/char/amiserial.c
+++ b/drivers/char/amiserial.c
@@ -837,9 +837,6 @@ static int rs_put_char(struct tty_struct *tty, unsigned char ch)
 	struct async_struct *info;
 	unsigned long flags;
 
-	if (!tty)
-		return 0;
-
 	info = tty->driver_data;
 
 	if (serial_paranoia_check(info, tty->name, "rs_put_char"))
@@ -892,9 +889,6 @@ static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count
 	struct async_struct *info;
 	unsigned long flags;
 
-	if (!tty)
-		return 0;
-
 	info = tty->driver_data;
 
 	if (serial_paranoia_check(info, tty->name, "rs_write"))
diff --git a/drivers/char/generic_serial.c b/drivers/char/generic_serial.c
index 19d3afb..c6090f8 100644
--- a/drivers/char/generic_serial.c
+++ b/drivers/char/generic_serial.c
@@ -54,8 +54,6 @@ int gs_put_char(struct tty_struct * tty, unsigned char ch)
 
 	func_enter (); 
 
-	if (!tty) return 0;
-
 	port = tty->driver_data;
 
 	if (!port) return 0;
@@ -97,8 +95,6 @@ int gs_write(struct tty_struct * tty,
 
 	func_enter ();
 
-	if (!tty) return 0;
-
 	port = tty->driver_data;
 
 	if (!port) return 0;
@@ -185,7 +181,6 @@ static int gs_real_chars_in_buffer(struct tty_struct *tty)
 	struct gs_port *port;
 	func_enter ();
 
-	if (!tty) return 0;
 	port = tty->driver_data;
 
 	if (!port->rd) return 0;
@@ -274,8 +269,6 @@ void gs_flush_buffer(struct tty_struct *tty)
 
 	func_enter ();
 
-	if (!tty) return;
-
 	port = tty->driver_data;
 
 	if (!port) return;
@@ -296,8 +289,6 @@ void gs_flush_chars(struct tty_struct * tty)
 
 	func_enter ();
 
-	if (!tty) return;
-
 	port = tty->driver_data;
 
 	if (!port) return;
@@ -321,8 +312,6 @@ void gs_stop(struct tty_struct * tty)
 
 	func_enter ();
 
-	if (!tty) return;
-
 	port = tty->driver_data;
 
 	if (!port) return;
@@ -341,8 +330,6 @@ void gs_start(struct tty_struct * tty)
 {
 	struct gs_port *port;
 
-	if (!tty) return;
-
 	port = tty->driver_data;
 
 	if (!port) return;
@@ -393,8 +380,6 @@ void gs_hangup(struct tty_struct *tty)
 
 	func_enter ();
 
-	if (!tty) return;
-
 	port = tty->driver_data;
 	tty = port->port.tty;
 	if (!tty) 
@@ -426,8 +411,6 @@ int gs_block_til_ready(void *port_, struct file * filp)
 
 	tty = port->port.tty;
 
-	if (!tty) return 0;
-
 	gs_dprintk (GS_DEBUG_BTR, "Entering gs_block_till_ready.\n"); 
 	/*
 	 * If the device is in the middle of being closed, then block
@@ -523,8 +506,6 @@ void gs_close(struct tty_struct * tty, struct file * filp)
 	
 	func_enter ();
 
-	if (!tty) return;
-
 	port = (struct gs_port *) tty->driver_data;
 
 	if (!port) return;
@@ -621,8 +602,6 @@ void gs_set_termios (struct tty_struct * tty,
 
 	func_enter();
 
-	if (!tty) return;
-
 	port = tty->driver_data;
 
 	if (!port) return;
diff --git a/drivers/char/istallion.c b/drivers/char/istallion.c
index 96ee112..505d7a1 100644
--- a/drivers/char/istallion.c
+++ b/drivers/char/istallion.c
@@ -1375,8 +1375,6 @@ static void stli_flushchars(struct tty_struct *tty)
 	stli_txcookrealsize = 0;
 	stli_txcooktty = NULL;
 
-	if (tty == NULL)
-		return;
 	if (cooktty == NULL)
 		return;
 	if (tty != cooktty)
@@ -1732,8 +1730,6 @@ static void stli_settermios(struct tty_struct *tty, struct ktermios *old)
 	struct ktermios *tiosp;
 	asyport_t aport;
 
-	if (tty == NULL)
-		return;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return;
@@ -1938,8 +1934,6 @@ static void stli_waituntilsent(struct tty_struct *tty, int timeout)
 	struct stliport *portp;
 	unsigned long tend;
 
-	if (tty == NULL)
-		return;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return;
diff --git a/drivers/char/mxser.c b/drivers/char/mxser.c
index 308cb60..8beef50 100644
--- a/drivers/char/mxser.c
+++ b/drivers/char/mxser.c
@@ -616,9 +616,6 @@ static int mxser_set_baud(struct tty_struct *tty, long newspd)
 	int quot = 0, baud;
 	unsigned char cval;
 
-	if (!tty->termios)
-		return -1;
-
 	if (!info->ioaddr)
 		return -1;
 
@@ -688,8 +685,6 @@ static int mxser_change_speed(struct tty_struct *tty,
 	int ret = 0;
 	unsigned char status;
 
-	if (!tty->termios)
-		return ret;
 	cflag = tty->termios->c_cflag;
 	if (!info->ioaddr)
 		return ret;
diff --git a/drivers/char/n_r3964.c b/drivers/char/n_r3964.c
index ae377aa..4a8215a 100644
--- a/drivers/char/n_r3964.c
+++ b/drivers/char/n_r3964.c
@@ -372,14 +372,8 @@ static void remove_from_rx_queue(struct r3964_info *pInfo,
 static void put_char(struct r3964_info *pInfo, unsigned char ch)
 {
 	struct tty_struct *tty = pInfo->tty;
-
-	if (tty == NULL)
-		return;
-
 	/* FIXME: put_char should not be called from an IRQ */
-	if (tty->ops->put_char) {
-		tty->ops->put_char(tty, ch);
-	}
+	tty_put_char(tty, ch);
 	pInfo->bcc ^= ch;
 }
 
diff --git a/drivers/char/stallion.c b/drivers/char/stallion.c
index 81b3234..8b8f07a 100644
--- a/drivers/char/stallion.c
+++ b/drivers/char/stallion.c
@@ -849,8 +849,6 @@ static void stl_flushbuffer(struct tty_struct *tty)
 
 	pr_debug("stl_flushbuffer(tty=%p)\n", tty);
 
-	if (tty == NULL)
-		return;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return;
@@ -868,8 +866,6 @@ static void stl_waituntilsent(struct tty_struct *tty, int timeout)
 
 	pr_debug("stl_waituntilsent(tty=%p,timeout=%d)\n", tty, timeout);
 
-	if (tty == NULL)
-		return;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return;
@@ -1036,8 +1032,6 @@ static int stl_putchar(struct tty_struct *tty, unsigned char ch)
 
 	pr_debug("stl_putchar(tty=%p,ch=%x)\n", tty, ch);
 
-	if (tty == NULL)
-		return -EINVAL;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return -EINVAL;
@@ -1073,8 +1067,6 @@ static void stl_flushchars(struct tty_struct *tty)
 
 	pr_debug("stl_flushchars(tty=%p)\n", tty);
 
-	if (tty == NULL)
-		return;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return;
@@ -1093,8 +1085,6 @@ static int stl_writeroom(struct tty_struct *tty)
 
 	pr_debug("stl_writeroom(tty=%p)\n", tty);
 
-	if (tty == NULL)
-		return 0;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return 0;
@@ -1125,8 +1115,6 @@ static int stl_charsinbuffer(struct tty_struct *tty)
 
 	pr_debug("stl_charsinbuffer(tty=%p)\n", tty);
 
-	if (tty == NULL)
-		return 0;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return 0;
@@ -1219,8 +1207,6 @@ static int stl_tiocmget(struct tty_struct *tty, struct file *file)
 {
 	struct stlport	*portp;
 
-	if (tty == NULL)
-		return -ENODEV;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return -ENODEV;
@@ -1236,8 +1222,6 @@ static int stl_tiocmset(struct tty_struct *tty, struct file *file,
 	struct stlport	*portp;
 	int rts = -1, dtr = -1;
 
-	if (tty == NULL)
-		return -ENODEV;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return -ENODEV;
@@ -1266,8 +1250,6 @@ static int stl_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd
 	pr_debug("stl_ioctl(tty=%p,file=%p,cmd=%x,arg=%lx)\n", tty, file, cmd,
 			arg);
 
-	if (tty == NULL)
-		return -ENODEV;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return -ENODEV;
@@ -1321,8 +1303,6 @@ static void stl_start(struct tty_struct *tty)
 
 	pr_debug("stl_start(tty=%p)\n", tty);
 
-	if (tty == NULL)
-		return;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return;
@@ -1338,8 +1318,6 @@ static void stl_settermios(struct tty_struct *tty, struct ktermios *old)
 
 	pr_debug("stl_settermios(tty=%p,old=%p)\n", tty, old);
 
-	if (tty == NULL)
-		return;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return;
@@ -1373,8 +1351,6 @@ static void stl_throttle(struct tty_struct *tty)
 
 	pr_debug("stl_throttle(tty=%p)\n", tty);
 
-	if (tty == NULL)
-		return;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return;
@@ -1393,8 +1369,6 @@ static void stl_unthrottle(struct tty_struct *tty)
 
 	pr_debug("stl_unthrottle(tty=%p)\n", tty);
 
-	if (tty == NULL)
-		return;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return;
@@ -1414,8 +1388,6 @@ static void stl_stop(struct tty_struct *tty)
 
 	pr_debug("stl_stop(tty=%p)\n", tty);
 
-	if (tty == NULL)
-		return;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return;
@@ -1436,8 +1408,6 @@ static void stl_hangup(struct tty_struct *tty)
 
 	pr_debug("stl_hangup(tty=%p)\n", tty);
 
-	if (tty == NULL)
-		return;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return;
@@ -1470,8 +1440,6 @@ static int stl_breakctl(struct tty_struct *tty, int state)
 
 	pr_debug("stl_breakctl(tty=%p,state=%d)\n", tty, state);
 
-	if (tty == NULL)
-		return -EINVAL;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return -EINVAL;
@@ -1488,8 +1456,6 @@ static void stl_sendxchar(struct tty_struct *tty, char ch)
 
 	pr_debug("stl_sendxchar(tty=%p,ch=%x)\n", tty, ch);
 
-	if (tty == NULL)
-		return;
 	portp = tty->driver_data;
 	if (portp == NULL)
 		return;


  parent reply	other threads:[~2008-10-13 10:03 UTC|newest]

Thread overview: 86+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-13  9:31 [PATCH 00/80] TTY updates for 2.6.28 Alan Cox
2008-10-13  9:31 ` [PATCH 01/80] drivers/serial/crisv10.c: add missing put_tty_driver Alan Cox
2008-10-13  9:31 ` [PATCH 02/80] drivers/char/hvc_console.c: adjust call to put_tty_driver Alan Cox
2008-10-13  9:31 ` [PATCH 03/80] coldfire: scheduled SERIAL_COLDFIRE removal Alan Cox
2008-10-13  9:32 ` [PATCH 04/80] epca: call tty_port_init Alan Cox
2008-10-13  9:32 ` [PATCH 05/80] Blackfin Serial Driver: use __initdata for data, not __init Alan Cox
2008-10-13  9:32 ` [PATCH 06/80] Blackfin Serial Driver: Fix bug - should suspend/resume/remove all uart ports Alan Cox
2008-10-13  9:33 ` [PATCH 07/80] Blackfin Serial Driver: trim trailing whitespace -- no functional changes Alan Cox
2008-10-13  9:33 ` [PATCH 08/80] Blackfin Serial Driver: move common variables out of serial headers and into the serial driver Alan Cox
2008-10-13  9:33 ` [PATCH 09/80] Blackfin Serial Driver: Remove useless stop Alan Cox
2008-10-13  9:33 ` [PATCH 10/80] Blackfin Serial Driver: Fix bug - Don't call tx_stop in tx_transfer Alan Cox
2008-10-13  9:33 ` [PATCH 11/80] Blackfin Serial Driver: Fix bug - ircp fails on sir over Blackfin UART Alan Cox
2008-10-13  9:33 ` [PATCH 12/80] Blackfin Serial Driver: Fix bug - request UART2/3 peripheral mapped interrupts in PIO mode Alan Cox
2008-10-13  9:34 ` [PATCH 13/80] Fix oti6858 debug level Alan Cox
2008-10-13  9:34 ` [PATCH 14/80] Char: cyclades. remove bogus iomap Alan Cox
2008-10-13  9:34 ` [PATCH 15/80] Char: sx, fix io unmapping Alan Cox
2008-10-13  9:34 ` [PATCH 16/80] Char: merge ip2main and ip2base Alan Cox
2008-10-13  9:34 ` [PATCH 17/80] ip2, cleanup globals Alan Cox
2008-10-13  9:34 ` [PATCH 18/80] ip2, fix sparse warnings Alan Cox
2008-10-13  9:34 ` [PATCH 19/80] ip2, init/deinit cleanup Alan Cox
2008-10-13  9:35 ` [PATCH 20/80] ip2: avoid add_timer with pending timer Alan Cox
2008-10-13  9:35 ` [PATCH 21/80] audit: Handle embedded NUL in TTY input auditing Alan Cox
2008-10-13  9:35 ` [PATCH 22/80] serial: Make uart_port's ioport "unsigned long" Alan Cox
2008-10-13  9:35 ` [PATCH 23/80] nozomi: Fix close on error Alan Cox
2008-10-13  9:35 ` [PATCH 24/80] serial-make-uart_ports-ioport-unsigned-long-fix Alan Cox
2008-10-13  9:35 ` [PATCH 25/80] usb: fix pl2303 initialization Alan Cox
2008-10-13  9:36 ` [PATCH 26/80] ftdi: A few errors are err() that should be debug which causes much spewage Alan Cox
2008-10-13  9:36 ` [PATCH 27/80] serial_8250: pci_enable_device fail is not fully handled Alan Cox
2008-10-13  9:36 ` [PATCH 28/80] 8250: remove a few inlines of dubious value Alan Cox
2008-10-13  9:36 ` [PATCH 29/80] serial: allow 8250 to be used on sparc Alan Cox
2008-10-13  9:36 ` [PATCH 30/80] tty: move tioclinux from a special case Alan Cox
2008-10-13  9:36 ` [PATCH 31/80] uml: small cleanups and note bugs to be dealt with by uml authors Alan Cox
2008-10-13  9:36 ` [PATCH 32/80] tty: split the buffering from tty_io Alan Cox
2008-10-13  9:37 ` [PATCH 33/80] tty: Split tty_port into its own file Alan Cox
2008-10-13  9:37 ` [PATCH 34/80] pps: Reserve a line discipline number for PPS Alan Cox
2008-10-13  9:37 ` [PATCH 35/80] tty: Add a kref count Alan Cox
2008-10-13  9:37 ` [PATCH 36/80] tty: use krefs to protect driver module counts Alan Cox
2008-10-13  9:37 ` [PATCH 37/80] tty: Cris has a nice RS485 ioctl so we should steal it Alan Cox
2008-10-13  9:38 ` [PATCH 38/80] tty: ipw need reworking Alan Cox
2008-10-13  9:38 ` [PATCH 39/80] tty: Add termiox Alan Cox
2008-10-13  9:38 ` [PATCH 40/80] tty: Termios locking - sort out real_tty confusions and lock reads Alan Cox
2008-10-13  9:39 ` [PATCH 41/80] tty: compare the tty winsize Alan Cox
2008-10-13  9:39 ` [PATCH 42/80] tty: Make get_current_tty use a kref Alan Cox
2008-10-13  9:39 ` [PATCH 43/80] tty: Move tty_write_message out of kernel/printk Alan Cox
2008-10-13  9:39 ` [PATCH 44/80] tty: usb-serial krefs Alan Cox
2008-10-13  9:39 ` [PATCH 45/80] tty: kref usage for isicom and moxa Alan Cox
2008-10-13  9:40 ` [PATCH 46/80] stallion: Use krefs Alan Cox
2008-10-13  9:40 ` [PATCH 47/80] mxser: Switch to kref tty Alan Cox
2008-10-13  9:40 ` [PATCH 48/80] tty: the vhangup syscall is racy Alan Cox
2008-10-13  9:40 ` [PATCH 49/80] tty: Redo current tty locking Alan Cox
2008-10-13  9:40 ` [PATCH 50/80] tty: Fix abusers of current->sighand->tty Alan Cox
2008-10-13  9:41 ` [PATCH 51/80] pty: If the administrator creates a device for a ptmx slave we should not error Alan Cox
2008-10-13  9:41 ` [PATCH 52/80] vt: remove bogus lock dropping Alan Cox
2008-10-13  9:41 ` [PATCH 53/80] tty: shutdown method Alan Cox
2008-10-13  9:41 ` [PATCH 54/80] tty: Remove more special casing and out of place code Alan Cox
2008-10-13  9:41 ` [PATCH 55/80] tty: Move parts of tty_init_dev into new functions Alan Cox
2008-10-13  9:42 ` [PATCH 56/80] tty: Clean up the tty_init_dev changes further Alan Cox
2008-10-13  9:42 ` [PATCH 57/80] tty: kref the tty driver object Alan Cox
2008-10-13  9:42 ` [PATCH 58/80] tty: More driver operations Alan Cox
2008-10-13  9:42 ` [PATCH 59/80] tty: Finish fixing up the init_dev interface to use ERR_PTR Alan Cox
2008-10-13  9:42 ` [PATCH 60/80] tty: extract the pty init time special cases Alan Cox
2008-10-13  9:42 ` [PATCH 61/80] Move tty lookup/reopen to caller Alan Cox
2008-10-13  9:42 ` [PATCH 62/80] Add an instance parameter devpts interfaces Alan Cox
2008-10-13  9:43 ` [PATCH 63/80] Simplify devpts_get_tty() Alan Cox
2008-10-13  9:43 ` [PATCH 64/80] Simplify devpts_pty_new() Alan Cox
2008-10-13  9:43 ` [PATCH 65/80] Simplify devpts_pty_kill Alan Cox
2008-10-13  9:43 ` [PATCH 66/80] pty: Coding style and polish Alan Cox
2008-10-13  9:43 ` [PATCH 67/80] pty: Fix allocation failure double free Alan Cox
2008-10-13  9:43 ` [PATCH 68/80] pty: simplify unix98 allocation Alan Cox
2008-10-13  9:44 ` [PATCH 69/80] tty: simplify ktermios allocation Alan Cox
2008-10-13  9:44 ` [PATCH 70/80] tty: some ICANON magic is in the wrong places Alan Cox
2008-10-13  9:44 ` [PATCH 71/80] tty: Fallout from tty-move-canon-specials Alan Cox
2008-10-13  9:44 ` [PATCH 72/80] tty: fix up gigaset a bit Alan Cox
2008-10-16 15:50   ` Tilman Schmidt
2008-10-17 11:40     ` Alan Cox
2008-10-19 12:28       ` Tilman Schmidt
2008-10-22  9:00         ` Alan Cox
2008-10-24 11:21           ` Tilman Schmidt
2008-10-13  9:44 ` Alan Cox [this message]
2008-10-13  9:45 ` [PATCH 74/80] tty: Minor tidyups and document fixes for n_tty Alan Cox
2008-10-13  9:45 ` [PATCH 75/80] applicom: Fix an unchecked user ioctl range and an error return Alan Cox
2008-10-13  9:45 ` [PATCH 76/80] serial: fix device name reporting when minor space is shared between drivers Alan Cox
2008-10-13  9:45 ` [PATCH 77/80] tty: tty_io.c shadows sparse fix Alan Cox
2008-10-13  9:45 ` [PATCH 78/80] fs3270: remove extra locks Alan Cox
2008-10-13  9:46 ` [PATCH 79/80] fs3270: Correct error returns Alan Cox
2008-10-13  9:46 ` [PATCH 80/80] tty: rename the remaining oddly named n_tty functions Alan Cox

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