Re: [PATCH 1/5] tty: remove TTY_MAGIC
From: Jiri Slaby
Date: Fri Sep 16 2022 - 02:51:31 EST
On 16. 09. 22, 3:54, наб wrote:
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>
What a good riddance! We have by far better debugging techniques nowadays.
Acked-by: Jiri Slaby <jirislaby@xxxxxxxxxx>
---
Whole series: amd64 allyesconfig builds; amd64 Debian config boots and
appears to work; naturally, the HVC stuff is S/390 only, but it's a
constant offset
Documentation/process/magic-number.rst | 1 -
Documentation/translations/it_IT/process/magic-number.rst | 1 -
Documentation/translations/zh_CN/process/magic-number.rst | 1 -
Documentation/translations/zh_TW/process/magic-number.rst | 1 -
drivers/tty/tty_io.c | 8 --------
drivers/tty/tty_mutex.c | 6 ------
include/linux/tty.h | 6 ------
7 files changed, 24 deletions(-)
diff --git a/Documentation/process/magic-number.rst b/Documentation/process/magic-number.rst
index f5ba36e96461..b4c7ec61437e 100644
--- a/Documentation/process/magic-number.rst
+++ b/Documentation/process/magic-number.rst
@@ -84,7 +84,6 @@ SLIP_MAGIC 0x5302 slip ``drivers/net/sl
STRIP_MAGIC 0x5303 strip ``drivers/net/strip.c``
SIXPACK_MAGIC 0x5304 sixpack ``drivers/net/hamradio/6pack.h``
AX25_MAGIC 0x5316 ax_disp ``drivers/net/mkiss.h``
-TTY_MAGIC 0x5401 tty_struct ``include/linux/tty.h``
MGSL_MAGIC 0x5401 mgsl_info ``drivers/char/synclink.c``
TTY_DRIVER_MAGIC 0x5402 tty_driver ``include/linux/tty_driver.h``
MGSLPC_MAGIC 0x5402 mgslpc_info ``drivers/char/pcmcia/synclink_cs.c``
diff --git a/Documentation/translations/it_IT/process/magic-number.rst b/Documentation/translations/it_IT/process/magic-number.rst
index f452fafb1e84..bcb23384fefd 100644
--- a/Documentation/translations/it_IT/process/magic-number.rst
+++ b/Documentation/translations/it_IT/process/magic-number.rst
@@ -90,7 +90,6 @@ SLIP_MAGIC 0x5302 slip ``drivers/net/sl
STRIP_MAGIC 0x5303 strip ``drivers/net/strip.c``
SIXPACK_MAGIC 0x5304 sixpack ``drivers/net/hamradio/6pack.h``
AX25_MAGIC 0x5316 ax_disp ``drivers/net/mkiss.h``
-TTY_MAGIC 0x5401 tty_struct ``include/linux/tty.h``
MGSL_MAGIC 0x5401 mgsl_info ``drivers/char/synclink.c``
TTY_DRIVER_MAGIC 0x5402 tty_driver ``include/linux/tty_driver.h``
MGSLPC_MAGIC 0x5402 mgslpc_info ``drivers/char/pcmcia/synclink_cs.c``
diff --git a/Documentation/translations/zh_CN/process/magic-number.rst b/Documentation/translations/zh_CN/process/magic-number.rst
index 42f0635ca70a..6250087d36c5 100644
--- a/Documentation/translations/zh_CN/process/magic-number.rst
+++ b/Documentation/translations/zh_CN/process/magic-number.rst
@@ -73,7 +73,6 @@ SLIP_MAGIC 0x5302 slip ``drivers/net/sl
STRIP_MAGIC 0x5303 strip ``drivers/net/strip.c``
SIXPACK_MAGIC 0x5304 sixpack ``drivers/net/hamradio/6pack.h``
AX25_MAGIC 0x5316 ax_disp ``drivers/net/mkiss.h``
-TTY_MAGIC 0x5401 tty_struct ``include/linux/tty.h``
MGSL_MAGIC 0x5401 mgsl_info ``drivers/char/synclink.c``
TTY_DRIVER_MAGIC 0x5402 tty_driver ``include/linux/tty_driver.h``
MGSLPC_MAGIC 0x5402 mgslpc_info ``drivers/char/pcmcia/synclink_cs.c``
diff --git a/Documentation/translations/zh_TW/process/magic-number.rst b/Documentation/translations/zh_TW/process/magic-number.rst
index ae321a9aaece..fd169d760bbd 100644
--- a/Documentation/translations/zh_TW/process/magic-number.rst
+++ b/Documentation/translations/zh_TW/process/magic-number.rst
@@ -76,7 +76,6 @@ SLIP_MAGIC 0x5302 slip ``drivers/net/sl
STRIP_MAGIC 0x5303 strip ``drivers/net/strip.c``
SIXPACK_MAGIC 0x5304 sixpack ``drivers/net/hamradio/6pack.h``
AX25_MAGIC 0x5316 ax_disp ``drivers/net/mkiss.h``
-TTY_MAGIC 0x5401 tty_struct ``include/linux/tty.h``
MGSL_MAGIC 0x5401 mgsl_info ``drivers/char/synclink.c``
TTY_DRIVER_MAGIC 0x5402 tty_driver ``include/linux/tty_driver.h``
MGSLPC_MAGIC 0x5402 mgslpc_info ``drivers/char/pcmcia/synclink_cs.c``
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 82a8855981f7..33962109bd10 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -170,7 +170,6 @@ static void free_tty_struct(struct tty_struct *tty)
tty_ldisc_deinit(tty);
put_device(tty->dev);
kvfree(tty->write_buf);
- tty->magic = 0xDEADDEAD;
kfree(tty);
}
@@ -265,11 +264,6 @@ static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
imajor(inode), iminor(inode), routine);
return 1;
}
- if (tty->magic != TTY_MAGIC) {
- pr_warn("(%d:%d): %s: bad magic number\n",
- imajor(inode), iminor(inode), routine);
- return 1;
- }
#endif
return 0;
}
@@ -1533,7 +1527,6 @@ static void release_one_tty(struct work_struct *work)
if (tty->ops->cleanup)
tty->ops->cleanup(tty);
- tty->magic = 0;
tty_driver_kref_put(driver);
module_put(owner);
@@ -3093,7 +3086,6 @@ struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx)
return NULL;
kref_init(&tty->kref);
- tty->magic = TTY_MAGIC;
if (tty_ldisc_init(tty)) {
kfree(tty);
return NULL;
diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c
index 393518a24cfe..784e46a0a3b1 100644
--- a/drivers/tty/tty_mutex.c
+++ b/drivers/tty/tty_mutex.c
@@ -14,8 +14,6 @@
void tty_lock(struct tty_struct *tty)
{
- if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
- return;
tty_kref_get(tty);
mutex_lock(&tty->legacy_mutex);
}
@@ -25,8 +23,6 @@ int tty_lock_interruptible(struct tty_struct *tty)
{
int ret;
- if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
- return -EIO;
tty_kref_get(tty);
ret = mutex_lock_interruptible(&tty->legacy_mutex);
if (ret)
@@ -36,8 +32,6 @@ int tty_lock_interruptible(struct tty_struct *tty)
void tty_unlock(struct tty_struct *tty)
{
- if (WARN(tty->magic != TTY_MAGIC, "U Bad %p\n", tty))
- return;
mutex_unlock(&tty->legacy_mutex);
tty_kref_put(tty);
}
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 7b0a5d478ef6..ba65043e9029 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -122,8 +122,6 @@ struct tty_operations;
/**
* struct tty_struct - state associated with a tty while open
*
- * @magic: magic value set early in @alloc_tty_struct to %TTY_MAGIC, for
- * debugging purposes
* @kref: reference counting by tty_kref_get() and tty_kref_put(), reaching zero
* frees the structure
* @dev: class device or %NULL (e.g. ptys, serdev)
@@ -193,7 +191,6 @@ struct tty_operations;
* &struct tty_port.
*/
struct tty_struct {
- int magic;
struct kref kref;
struct device *dev;
struct tty_driver *driver;
@@ -260,9 +257,6 @@ struct tty_file_private {
struct list_head list;
};
-/* tty magic number */
-#define TTY_MAGIC 0x5401
-
/**
* DOC: TTY Struct Flags
*
--
js
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