[PATCH 00/13] tty: random fixes and cleanups

[PATCH 00/13] tty: random fixes and cleanups

[Jiri Slaby (SUSE)]

Hi,

this is a series of locally accumulated patches over past months.

The series:
* makes mctp and 6pack use u8s,
* cleans up 6pack a bit,
* fixes two coverity reports,
* uses guard() to make some of the tty function easier to follow.

Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jeremy Kerr <jk@codeconstruct.com.au>
Cc: linux-hams@vger.kernel.org
Cc: Matt Johnston <matt@codeconstruct.com.au>
Cc: netdev@vger.kernel.org
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Peter Hurley <peter@hurleysoftware.com>


Jiri Slaby (SUSE) (13):
  tty: simplify tty_dev_name_to_number() using guard(mutex)
  serial: protect uart_port_dtr_rts() in uart_shutdown() too
  serial: don't use uninitialized value in uart_poll_init()
  serial: remove quot_frac from serial8250_do_set_divisor()
  serial: use guards for simple mutex locks
  mxser: remove stale comment
  mxser: remove doubled sets of close times
  mctp: serial: propagage new tty types
  6pack: remove sixpack::rbuff
  6pack: drop sixpack::mtu
  6pack: drop sixpack::buffsize
  6pack: remove global strings
  6pack: propagage new tty types

 drivers/net/hamradio/6pack.c         |  60 ++++--------
 drivers/net/mctp/mctp-serial.c       |  23 ++---
 drivers/tty/mxser.c                  |   5 -
 drivers/tty/serial/8250/8250_dwlib.c |   2 +-
 drivers/tty/serial/8250/8250_exar.c  |   2 +-
 drivers/tty/serial/8250/8250_pci.c   |   2 +-
 drivers/tty/serial/8250/8250_port.c  |   4 +-
 drivers/tty/serial/serial_core.c     | 140 ++++++++++++---------------
 drivers/tty/tty_io.c                 |  11 +--
 include/linux/serial_8250.h          |   2 +-
 10 files changed, 103 insertions(+), 148 deletions(-)

-- 
2.46.0

[PATCH 09/13] 6pack: remove sixpack::rbuff

[Jiri Slaby (SUSE)]

It's unused (except allocation and free).

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-hams@vger.kernel.org
Cc: netdev@vger.kernel.org
---
 drivers/net/hamradio/6pack.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 6ed38a3cdd73..29906901a734 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -88,7 +88,6 @@ struct sixpack {
 	struct net_device	*dev;		/* easy for intr handling  */
 
 	/* These are pointers to the malloc()ed frame buffers. */
-	unsigned char		*rbuff;		/* receiver buffer	*/
 	int			rcount;         /* received chars counter  */
 	unsigned char		*xbuff;		/* transmitter buffer	*/
 	unsigned char		*xhead;         /* next byte to XMIT */
@@ -544,7 +543,7 @@ static inline int tnc_init(struct sixpack *sp)
  */
 static int sixpack_open(struct tty_struct *tty)
 {
-	char *rbuff = NULL, *xbuff = NULL;
+	char *xbuff = NULL;
 	struct net_device *dev;
 	struct sixpack *sp;
 	unsigned long len;
@@ -574,10 +573,8 @@ static int sixpack_open(struct tty_struct *tty)
 
 	len = dev->mtu * 2;
 
-	rbuff = kmalloc(len + 4, GFP_KERNEL);
 	xbuff = kmalloc(len + 4, GFP_KERNEL);
-
-	if (rbuff == NULL || xbuff == NULL) {
+	if (xbuff == NULL) {
 		err = -ENOBUFS;
 		goto out_free;
 	}
@@ -586,7 +583,6 @@ static int sixpack_open(struct tty_struct *tty)
 
 	sp->tty = tty;
 
-	sp->rbuff	= rbuff;
 	sp->xbuff	= xbuff;
 
 	sp->mtu		= AX25_MTU + 73;
@@ -631,7 +627,6 @@ static int sixpack_open(struct tty_struct *tty)
 
 out_free:
 	kfree(xbuff);
-	kfree(rbuff);
 
 	free_netdev(dev);
 
@@ -676,7 +671,6 @@ static void sixpack_close(struct tty_struct *tty)
 	del_timer_sync(&sp->resync_t);
 
 	/* Free all 6pack frame buffers after unreg. */
-	kfree(sp->rbuff);
 	kfree(sp->xbuff);
 
 	free_netdev(sp->dev);
-- 
2.46.0

[PATCH 10/13] 6pack: drop sixpack::mtu

[Jiri Slaby (SUSE)]

It holds a constant (AX25_MTU + 73), so use that constant in place of
the single use directly.

And remove the stale comment.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-hams@vger.kernel.org
Cc: netdev@vger.kernel.org
---
 drivers/net/hamradio/6pack.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 29906901a734..f8235b1b60e9 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -100,7 +100,6 @@ struct sixpack {
 	unsigned int		rx_count_cooked;
 	spinlock_t		rxlock;
 
-	int			mtu;		/* Our mtu (to spot changes!) */
 	int			buffsize;       /* Max buffers sizes */
 
 	unsigned long		flags;		/* Flag values/ mode etc */
@@ -166,7 +165,7 @@ static void sp_encaps(struct sixpack *sp, unsigned char *icp, int len)
 	unsigned char *msg, *p = icp;
 	int actual, count;
 
-	if (len > sp->mtu) {	/* sp->mtu = AX25_MTU = max. PACLEN = 256 */
+	if (len > AX25_MTU + 73) {
 		msg = "oversized transmit packet!";
 		goto out_drop;
 	}
@@ -585,7 +584,6 @@ static int sixpack_open(struct tty_struct *tty)
 
 	sp->xbuff	= xbuff;
 
-	sp->mtu		= AX25_MTU + 73;
 	sp->buffsize	= len;
 	sp->rcount	= 0;
 	sp->rx_count	= 0;
-- 
2.46.0

[PATCH 11/13] 6pack: drop sixpack::buffsize

[Jiri Slaby (SUSE)]

It's never read.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-hams@vger.kernel.org
Cc: netdev@vger.kernel.org
---
 drivers/net/hamradio/6pack.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index f8235b1b60e9..25d6d2308130 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -100,8 +100,6 @@ struct sixpack {
 	unsigned int		rx_count_cooked;
 	spinlock_t		rxlock;
 
-	int			buffsize;       /* Max buffers sizes */
-
 	unsigned long		flags;		/* Flag values/ mode etc */
 	unsigned char		mode;		/* 6pack mode */
 
@@ -584,7 +582,6 @@ static int sixpack_open(struct tty_struct *tty)
 
 	sp->xbuff	= xbuff;
 
-	sp->buffsize	= len;
 	sp->rcount	= 0;
 	sp->rx_count	= 0;
 	sp->rx_count_cooked = 0;
-- 
2.46.0

[PATCH 12/13] 6pack: remove global strings

[Jiri Slaby (SUSE)]

They are __init, so they are freed after init is done. But this
obfuscates the code.

Provided these days, we usually don't print anything if everything has
gone fine, drop the info print completely (along with now unused and
always artificial SIXPACK_VERSION).

And move the other string into the printk proper (while converting from
KERN_ERR to pr_err()).

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-hams@vger.kernel.org
Cc: netdev@vger.kernel.org
---
 drivers/net/hamradio/6pack.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 25d6d2308130..5c47730f5d58 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -37,8 +37,6 @@
 #include <linux/semaphore.h>
 #include <linux/refcount.h>
 
-#define SIXPACK_VERSION    "Revision: 0.3.0"
-
 /* sixpack priority commands */
 #define SIXP_SEOF		0x40	/* start and end of a 6pack frame */
 #define SIXP_TX_URUN		0x48	/* transmit overrun */
@@ -745,21 +743,14 @@ static struct tty_ldisc_ops sp_ldisc = {
 
 /* Initialize 6pack control device -- register 6pack line discipline */
 
-static const char msg_banner[]  __initconst = KERN_INFO \
-	"AX.25: 6pack driver, " SIXPACK_VERSION "\n";
-static const char msg_regfail[] __initconst = KERN_ERR  \
-	"6pack: can't register line discipline (err = %d)\n";
-
 static int __init sixpack_init_driver(void)
 {
 	int status;
 
-	printk(msg_banner);
-
 	/* Register the provided line protocol discipline */
 	status = tty_register_ldisc(&sp_ldisc);
 	if (status)
-		printk(msg_regfail, status);
+		pr_err("6pack: can't register line discipline (err = %d)\n", status);
 
 	return status;
 }
-- 
2.46.0

[PATCH 13/13] 6pack: propagage new tty types

[Jiri Slaby (SUSE)]

In tty, u8 is now used for data, ssize_t for sizes (with possible
negative error codes). Propagate these types to 6pack.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-hams@vger.kernel.org
Cc: netdev@vger.kernel.org
---
 drivers/net/hamradio/6pack.c | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 5c47730f5d58..3bf6785f9057 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -91,8 +91,8 @@ struct sixpack {
 	unsigned char		*xhead;         /* next byte to XMIT */
 	int			xleft;          /* bytes left in XMIT queue  */
 
-	unsigned char		raw_buf[4];
-	unsigned char		cooked_buf[400];
+	u8			raw_buf[4];
+	u8			cooked_buf[400];
 
 	unsigned int		rx_count;
 	unsigned int		rx_count_cooked;
@@ -107,8 +107,8 @@ struct sixpack {
 	unsigned char		slottime;
 	unsigned char		duplex;
 	unsigned char		led_state;
-	unsigned char		status;
-	unsigned char		status1;
+	u8			status;
+	u8			status1;
 	unsigned char		status2;
 	unsigned char		tx_enable;
 	unsigned char		tnc_state;
@@ -122,7 +122,7 @@ struct sixpack {
 
 #define AX25_6PACK_HEADER_LEN 0
 
-static void sixpack_decode(struct sixpack *, const unsigned char[], int);
+static void sixpack_decode(struct sixpack *, const u8 *, size_t);
 static int encode_sixpack(unsigned char *, unsigned char *, int, unsigned char);
 
 /*
@@ -327,7 +327,7 @@ static void sp_bump(struct sixpack *sp, char cmd)
 {
 	struct sk_buff *skb;
 	int count;
-	unsigned char *ptr;
+	u8 *ptr;
 
 	count = sp->rcount + 1;
 
@@ -425,7 +425,7 @@ static void sixpack_receive_buf(struct tty_struct *tty, const u8 *cp,
 				const u8 *fp, size_t count)
 {
 	struct sixpack *sp;
-	int count1;
+	size_t count1;
 
 	if (!count)
 		return;
@@ -800,9 +800,9 @@ static int encode_sixpack(unsigned char *tx_buf, unsigned char *tx_buf_raw,
 
 /* decode 4 sixpack-encoded bytes into 3 data bytes */
 
-static void decode_data(struct sixpack *sp, unsigned char inbyte)
+static void decode_data(struct sixpack *sp, u8 inbyte)
 {
-	unsigned char *buf;
+	u8 *buf;
 
 	if (sp->rx_count != 3) {
 		sp->raw_buf[sp->rx_count++] = inbyte;
@@ -828,9 +828,9 @@ static void decode_data(struct sixpack *sp, unsigned char inbyte)
 
 /* identify and execute a 6pack priority command byte */
 
-static void decode_prio_command(struct sixpack *sp, unsigned char cmd)
+static void decode_prio_command(struct sixpack *sp, u8 cmd)
 {
-	int actual;
+	ssize_t actual;
 
 	if ((cmd & SIXP_PRIO_DATA_MASK) != 0) {     /* idle ? */
 
@@ -878,9 +878,9 @@ static void decode_prio_command(struct sixpack *sp, unsigned char cmd)
 
 /* identify and execute a standard 6pack command byte */
 
-static void decode_std_command(struct sixpack *sp, unsigned char cmd)
+static void decode_std_command(struct sixpack *sp, u8 cmd)
 {
-	unsigned char checksum = 0, rest = 0;
+	u8 checksum = 0, rest = 0;
 	short i;
 
 	switch (cmd & SIXP_CMD_MASK) {     /* normal command */
@@ -928,10 +928,10 @@ static void decode_std_command(struct sixpack *sp, unsigned char cmd)
 /* decode a 6pack packet */
 
 static void
-sixpack_decode(struct sixpack *sp, const unsigned char *pre_rbuff, int count)
+sixpack_decode(struct sixpack *sp, const u8 *pre_rbuff, size_t count)
 {
-	unsigned char inbyte;
-	int count1;
+	size_t count1;
+	u8 inbyte;
 
 	for (count1 = 0; count1 < count; count1++) {
 		inbyte = pre_rbuff[count1];
-- 
2.46.0

Re: [PATCH 00/13] tty: random fixes and cleanups

[Greg KH]

On Mon, Aug 05, 2024 at 12:20:33PM +0200, Jiri Slaby (SUSE) wrote:
> Hi,
> 
> this is a series of locally accumulated patches over past months.
> 
> The series:
> * makes mctp and 6pack use u8s,
> * cleans up 6pack a bit,
> * fixes two coverity reports,
> * uses guard() to make some of the tty function easier to follow.

This series breaks the build for me:

drivers/tty/serial/serial_core.c: In function ‘uart_suspend_port’:
drivers/tty/serial/serial_core.c:2400:17: error: label ‘unlock’ used but not defined
 2400 |                 goto unlock;
      |                 ^~~~
make[5]: *** [scripts/Makefile.build:244: drivers/tty/serial/serial_core.o] Error 1
make[5]: *** Waiting for unfinished jobs....