[PATCH 3/5] tty: n_hdlc: remove HDLC_MAGIC

From: наб
Date: Thu Sep 15 2022 - 21:55:26 EST

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"

Ref: https://lore.kernel.org/linux-doc/YyMlovoskUcHLEb7@xxxxxxxxx/
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@xxxxxxxxxxxxxxxxxx>
---
Documentation/process/magic-number.rst | 1 -
.../it_IT/process/magic-number.rst | 1 -
.../zh_CN/process/magic-number.rst | 1 -
.../zh_TW/process/magic-number.rst | 1 -
drivers/tty/n_hdlc.c | 27 -------------------
5 files changed, 31 deletions(-)

diff --git a/Documentation/process/magic-number.rst b/Documentation/process/magic-number.rst
index d47799ba0ca4..fdaa3e4b1953 100644
--- a/Documentation/process/magic-number.rst
+++ b/Documentation/process/magic-number.rst
@@ -71,7 +71,6 @@ Magic Name Number Structure File
PG_MAGIC 'P' pg_{read,write}_hdr ``include/linux/pg.h``
CMAGIC 0x0111 user ``include/linux/a.out.h``
MKISS_DRIVER_MAGIC 0x04bf mkiss_channel ``drivers/net/mkiss.h``
-HDLC_MAGIC 0x239e n_hdlc ``drivers/char/n_hdlc.c``
APM_BIOS_MAGIC 0x4101 apm_user ``arch/x86/kernel/apm_32.c``
DB_MAGIC 0x4442 fc_info ``drivers/net/iph5526_novram.c``
DL_MAGIC 0x444d fc_info ``drivers/net/iph5526_novram.c``
diff --git a/Documentation/translations/it_IT/process/magic-number.rst b/Documentation/translations/it_IT/process/magic-number.rst
index 24022ab52ebb..1898f98875de 100644
--- a/Documentation/translations/it_IT/process/magic-number.rst
+++ b/Documentation/translations/it_IT/process/magic-number.rst
@@ -77,7 +77,6 @@ Nome magico Numero Struttura File
PG_MAGIC 'P' pg_{read,write}_hdr ``include/linux/pg.h``
CMAGIC 0x0111 user ``include/linux/a.out.h``
MKISS_DRIVER_MAGIC 0x04bf mkiss_channel ``drivers/net/mkiss.h``
-HDLC_MAGIC 0x239e n_hdlc ``drivers/char/n_hdlc.c``
APM_BIOS_MAGIC 0x4101 apm_user ``arch/x86/kernel/apm_32.c``
DB_MAGIC 0x4442 fc_info ``drivers/net/iph5526_novram.c``
DL_MAGIC 0x444d fc_info ``drivers/net/iph5526_novram.c``
diff --git a/Documentation/translations/zh_CN/process/magic-number.rst b/Documentation/translations/zh_CN/process/magic-number.rst
index 811804996283..911cdaeaf698 100644
--- a/Documentation/translations/zh_CN/process/magic-number.rst
+++ b/Documentation/translations/zh_CN/process/magic-number.rst
@@ -60,7 +60,6 @@ Linux 魔术数
PG_MAGIC 'P' pg_{read,write}_hdr ``include/linux/pg.h``
CMAGIC 0x0111 user ``include/linux/a.out.h``
MKISS_DRIVER_MAGIC 0x04bf mkiss_channel ``drivers/net/mkiss.h``
-HDLC_MAGIC 0x239e n_hdlc ``drivers/char/n_hdlc.c``
APM_BIOS_MAGIC 0x4101 apm_user ``arch/x86/kernel/apm_32.c``
DB_MAGIC 0x4442 fc_info ``drivers/net/iph5526_novram.c``
DL_MAGIC 0x444d fc_info ``drivers/net/iph5526_novram.c``
diff --git a/Documentation/translations/zh_TW/process/magic-number.rst b/Documentation/translations/zh_TW/process/magic-number.rst
index 8e37e00590f5..ac87f188235f 100644
--- a/Documentation/translations/zh_TW/process/magic-number.rst
+++ b/Documentation/translations/zh_TW/process/magic-number.rst
@@ -63,7 +63,6 @@ Linux 魔術數
PG_MAGIC 'P' pg_{read,write}_hdr ``include/linux/pg.h``
CMAGIC 0x0111 user ``include/linux/a.out.h``
MKISS_DRIVER_MAGIC 0x04bf mkiss_channel ``drivers/net/mkiss.h``
-HDLC_MAGIC 0x239e n_hdlc ``drivers/char/n_hdlc.c``
APM_BIOS_MAGIC 0x4101 apm_user ``arch/x86/kernel/apm_32.c``
DB_MAGIC 0x4442 fc_info ``drivers/net/iph5526_novram.c``
DL_MAGIC 0x444d fc_info ``drivers/net/iph5526_novram.c``
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index 94c1ec2dd754..b5aa27051119 100644
--- a/drivers/tty/n_hdlc.c
+++ b/drivers/tty/n_hdlc.c
@@ -76,8 +76,6 @@
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/

-#define HDLC_MAGIC 0x239e
-
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
@@ -124,7 +122,6 @@ struct n_hdlc_buf_list {

/**
* struct n_hdlc - per device instance data structure
- * @magic: magic value for structure
* @tbusy: reentrancy flag for tx wakeup code
* @woke_up: tx wakeup needs to be run again as it was called while @tbusy
* @tx_buf_list: list of pending transmit frame buffers
@@ -133,7 +130,6 @@ struct n_hdlc_buf_list {
* @rx_free_buf_list: list unused received frame buffers
*/
struct n_hdlc {
- int magic;
bool tbusy;
bool woke_up;
struct n_hdlc_buf_list tx_buf_list;
@@ -200,10 +196,6 @@ static void n_hdlc_tty_close(struct tty_struct *tty)
{
struct n_hdlc *n_hdlc = tty->disc_data;

- if (n_hdlc->magic != HDLC_MAGIC) {
- pr_warn("n_hdlc: trying to close unopened tty!\n");
- return;
- }
#if defined(TTY_NO_WRITE_SPLIT)
clear_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
#endif
@@ -386,12 +378,6 @@ static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *data,

pr_debug("%s() called count=%d\n", __func__, count);

- /* verify line is using HDLC discipline */
- if (n_hdlc->magic != HDLC_MAGIC) {
- pr_err("line not using HDLC discipline\n");
- return;
- }
-
if (count > maxframe) {
pr_debug("rx count>maxframesize, data discarded\n");
return;
@@ -542,9 +528,6 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,

pr_debug("%s() called count=%zd\n", __func__, count);

- if (n_hdlc->magic != HDLC_MAGIC)
- return -EIO;
-
/* verify frame size */
if (count > maxframe) {
pr_debug("%s: truncating user packet from %zu to %d\n",
@@ -609,10 +592,6 @@ static int n_hdlc_tty_ioctl(struct tty_struct *tty, unsigned int cmd,

pr_debug("%s() called %d\n", __func__, cmd);

- /* Verify the status of the device */
- if (n_hdlc->magic != HDLC_MAGIC)
- return -EBADF;
-
switch (cmd) {
case FIONREAD:
/* report count of read data available */
@@ -673,9 +652,6 @@ static __poll_t n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp,
struct n_hdlc *n_hdlc = tty->disc_data;
__poll_t mask = 0;

- if (n_hdlc->magic != HDLC_MAGIC)
- return 0;
-
/*
* queue the current process into any wait queue that may awaken in the
* future (read and write)
@@ -739,9 +715,6 @@ static struct n_hdlc *n_hdlc_alloc(void)
n_hdlc_alloc_buf(&n_hdlc->rx_free_buf_list, DEFAULT_RX_BUF_COUNT, "rx");
n_hdlc_alloc_buf(&n_hdlc->tx_free_buf_list, DEFAULT_TX_BUF_COUNT, "tx");

- /* Initialize the control block */
- n_hdlc->magic = HDLC_MAGIC;
-
return n_hdlc;

} /* end of n_hdlc_alloc() */
--
2.30.2

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