[v2,12/15] drivers: net: slip: remove SLIP_MAGIC

Message ID 091907215b5f648e4e01f32e8902c1260101c1ba.1667330271.git.nabijaczleweli@nabijaczleweli.xyz
State New
Headers
Series magic-number.rst funeral rites |

Commit Message

Ahelenia Ziemiańska Nov. 1, 2022, 11:05 p.m. UTC
  According to Greg, in the context of magic numbers as defined in
magic-number.rst, "the tty layer should not need this and I'll gladly
take patches".

We have largely moved away from this approach, and we have better
debugging instrumentation nowadays: kill it.

Additionally, all SLIP_MAGIC checks just early-exit instead of noting
the bug, so they're detrimental, if anything.

Link: https://lore.kernel.org/linux-doc/YyMlovoskUcHLEb7@kroah.com/
Reviewed-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
---
 Documentation/process/magic-number.rst                |  1 -
 .../translations/it_IT/process/magic-number.rst       |  1 -
 .../translations/zh_CN/process/magic-number.rst       |  1 -
 .../translations/zh_TW/process/magic-number.rst       |  1 -
 drivers/net/slip/slip.c                               | 11 +++++------
 drivers/net/slip/slip.h                               |  4 ----
 6 files changed, 5 insertions(+), 14 deletions(-)
  

Patch

diff --git a/Documentation/process/magic-number.rst b/Documentation/process/magic-number.rst
index 3b3e607e1cbc..e59c707ec785 100644
--- a/Documentation/process/magic-number.rst
+++ b/Documentation/process/magic-number.rst
@@ -69,6 +69,5 @@  Changelog::
 Magic Name            Number           Structure                File
 ===================== ================ ======================== ==========================================
 FASYNC_MAGIC          0x4601           fasync_struct            ``include/linux/fs.h``
-SLIP_MAGIC            0x5302           slip                     ``drivers/net/slip.h``
 CCB_MAGIC             0xf2691ad2       ccb                      ``drivers/scsi/ncr53c8xx.c``
 ===================== ================ ======================== ==========================================
diff --git a/Documentation/translations/it_IT/process/magic-number.rst b/Documentation/translations/it_IT/process/magic-number.rst
index e8c659b6a743..37a539867b6f 100644
--- a/Documentation/translations/it_IT/process/magic-number.rst
+++ b/Documentation/translations/it_IT/process/magic-number.rst
@@ -75,6 +75,5 @@  Registro dei cambiamenti::
 Nome magico           Numero           Struttura                File
 ===================== ================ ======================== ==========================================
 FASYNC_MAGIC          0x4601           fasync_struct            ``include/linux/fs.h``
-SLIP_MAGIC            0x5302           slip                     ``drivers/net/slip.h``
 CCB_MAGIC             0xf2691ad2       ccb                      ``drivers/scsi/ncr53c8xx.c``
 ===================== ================ ======================== ==========================================
diff --git a/Documentation/translations/zh_CN/process/magic-number.rst b/Documentation/translations/zh_CN/process/magic-number.rst
index 2105af32187c..8a3a3e872c52 100644
--- a/Documentation/translations/zh_CN/process/magic-number.rst
+++ b/Documentation/translations/zh_CN/process/magic-number.rst
@@ -58,6 +58,5 @@  Linux 魔术数
 魔术数名              数字             结构                     文件
 ===================== ================ ======================== ==========================================
 FASYNC_MAGIC          0x4601           fasync_struct            ``include/linux/fs.h``
-SLIP_MAGIC            0x5302           slip                     ``drivers/net/slip.h``
 CCB_MAGIC             0xf2691ad2       ccb                      ``drivers/scsi/ncr53c8xx.c``
 ===================== ================ ======================== ==========================================
diff --git a/Documentation/translations/zh_TW/process/magic-number.rst b/Documentation/translations/zh_TW/process/magic-number.rst
index 793a0ae9fb7c..7ace7834f7f9 100644
--- a/Documentation/translations/zh_TW/process/magic-number.rst
+++ b/Documentation/translations/zh_TW/process/magic-number.rst
@@ -61,6 +61,5 @@  Linux 魔術數
 魔術數名              數字             結構                     文件
 ===================== ================ ======================== ==========================================
 FASYNC_MAGIC          0x4601           fasync_struct            ``include/linux/fs.h``
-SLIP_MAGIC            0x5302           slip                     ``drivers/net/slip.h``
 CCB_MAGIC             0xf2691ad2       ccb                      ``drivers/scsi/ncr53c8xx.c``
 ===================== ================ ======================== ==========================================
diff --git a/drivers/net/slip/slip.c b/drivers/net/slip/slip.c
index 6865d32270e5..95f5c79772e7 100644
--- a/drivers/net/slip/slip.c
+++ b/drivers/net/slip/slip.c
@@ -426,7 +426,7 @@  static void slip_transmit(struct work_struct *work)
 
 	spin_lock_bh(&sl->lock);
 	/* First make sure we're connected. */
-	if (!sl->tty || sl->magic != SLIP_MAGIC || !netif_running(sl->dev)) {
+	if (!sl->tty || !netif_running(sl->dev)) {
 		spin_unlock_bh(&sl->lock);
 		return;
 	}
@@ -690,7 +690,7 @@  static void slip_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 {
 	struct slip *sl = tty->disc_data;
 
-	if (!sl || sl->magic != SLIP_MAGIC || !netif_running(sl->dev))
+	if (!sl || !netif_running(sl->dev))
 		return;
 
 	/* Read the characters out of the buffer */
@@ -761,7 +761,6 @@  static struct slip *sl_alloc(void)
 	sl = netdev_priv(dev);
 
 	/* Initialize channel control data */
-	sl->magic       = SLIP_MAGIC;
 	sl->dev	      	= dev;
 	spin_lock_init(&sl->lock);
 	INIT_WORK(&sl->tx_work, slip_transmit);
@@ -809,7 +808,7 @@  static int slip_open(struct tty_struct *tty)
 
 	err = -EEXIST;
 	/* First make sure we're not already connected. */
-	if (sl && sl->magic == SLIP_MAGIC)
+	if (sl)
 		goto err_exit;
 
 	/* OK.  Find a free SLIP channel to use. */
@@ -886,7 +885,7 @@  static void slip_close(struct tty_struct *tty)
 	struct slip *sl = tty->disc_data;
 
 	/* First make sure we're connected. */
-	if (!sl || sl->magic != SLIP_MAGIC || sl->tty != tty)
+	if (!sl || sl->tty != tty)
 		return;
 
 	spin_lock_bh(&sl->lock);
@@ -1080,7 +1079,7 @@  static int slip_ioctl(struct tty_struct *tty, unsigned int cmd,
 	int __user *p = (int __user *)arg;
 
 	/* First make sure we're connected. */
-	if (!sl || sl->magic != SLIP_MAGIC)
+	if (!sl)
 		return -EINVAL;
 
 	switch (cmd) {
diff --git a/drivers/net/slip/slip.h b/drivers/net/slip/slip.h
index 3d7f88b330c1..d7dbedd27669 100644
--- a/drivers/net/slip/slip.h
+++ b/drivers/net/slip/slip.h
@@ -50,8 +50,6 @@ 
 
 
 struct slip {
-  int			magic;
-
   /* Various fields. */
   struct tty_struct	*tty;		/* ptr to TTY structure		*/
   struct net_device	*dev;		/* easy for intr handling	*/
@@ -100,6 +98,4 @@  struct slip {
 #endif
 };
 
-#define SLIP_MAGIC 0x5302
-
 #endif	/* _LINUX_SLIP.H */