tty: constify tty_ldisc_ops

tty_ldisc_ops is not modified once registered, so make it const.

Signed-off-by: Qingfang Deng <dqfext@gmail.com>
Link: https://patch.msgid.link/20260206062004.1273890-1-dqfext@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 888f2f8f94819a517efa00c9bc8ad38f98c0e52b..27fe8236f66230d9ceaad63f26948f30671b0d9b 100644 (file)
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -44,7 +44,7 @@ enum {
 
 static DEFINE_RAW_SPINLOCK(tty_ldiscs_lock);
 /* Line disc dispatch table */
-static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS];
+static const struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS];
 
 /**
  * tty_register_ldisc  -       install a line discipline
@@ -55,7 +55,7 @@ static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS];
  *
  * Locking: takes %tty_ldiscs_lock to guard against ldisc races
  */
-int tty_register_ldisc(struct tty_ldisc_ops *new_ldisc)
+int tty_register_ldisc(const struct tty_ldisc_ops *new_ldisc)
 {
        unsigned long flags;
 
@@ -80,7 +80,7 @@ EXPORT_SYMBOL(tty_register_ldisc);
  * Locking: takes %tty_ldiscs_lock to guard against ldisc races
  */
 
-void tty_unregister_ldisc(struct tty_ldisc_ops *ldisc)
+void tty_unregister_ldisc(const struct tty_ldisc_ops *ldisc)
 {
        unsigned long flags;
 
@@ -90,10 +90,10 @@ void tty_unregister_ldisc(struct tty_ldisc_ops *ldisc)
 }
 EXPORT_SYMBOL(tty_unregister_ldisc);
 
-static struct tty_ldisc_ops *get_ldops(int disc)
+static const struct tty_ldisc_ops *get_ldops(int disc)
 {
        unsigned long flags;
-       struct tty_ldisc_ops *ldops, *ret;
+       const struct tty_ldisc_ops *ldops, *ret;
 
        raw_spin_lock_irqsave(&tty_ldiscs_lock, flags);
        ret = ERR_PTR(-EINVAL);
@@ -107,7 +107,7 @@ static struct tty_ldisc_ops *get_ldops(int disc)
        return ret;
 }
 
-static void put_ldops(struct tty_ldisc_ops *ldops)
+static void put_ldops(const struct tty_ldisc_ops *ldops)
 {
        unsigned long flags;
 
@@ -139,7 +139,7 @@ int tty_ldisc_autoload = IS_BUILTIN(CONFIG_LDISC_AUTOLOAD);
 static struct tty_ldisc *tty_ldisc_get(struct tty_struct *tty, int disc)
 {
        struct tty_ldisc *ld;
-       struct tty_ldisc_ops *ldops;
+       const struct tty_ldisc_ops *ldops;
 
        if (disc < N_TTY || disc >= NR_LDISCS)
                return ERR_PTR(-EINVAL);
@@ -202,7 +202,7 @@ static void tty_ldiscs_seq_stop(struct seq_file *m, void *v)
 static int tty_ldiscs_seq_show(struct seq_file *m, void *v)
 {
        int i = *(loff_t *)v;
-       struct tty_ldisc_ops *ldops;
+       const struct tty_ldisc_ops *ldops;
 
        ldops = get_ldops(i);
        if (IS_ERR(ldops))

diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index c5cccc3fc1e8dceb0adb7db5e987c3f2724d4f5a..d227a58e3e490ac9ba18a6369ba8a3d6c790cc70 100644 (file)
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -266,7 +266,7 @@ struct tty_ldisc_ops {
 };
 
 struct tty_ldisc {
-       struct tty_ldisc_ops *ops;
+       const struct tty_ldisc_ops *ops;
        struct tty_struct *tty;
 };
 
@@ -281,8 +281,8 @@ struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
 
 void tty_ldisc_flush(struct tty_struct *tty);
 
-int tty_register_ldisc(struct tty_ldisc_ops *new_ldisc);
-void tty_unregister_ldisc(struct tty_ldisc_ops *ldisc);
+int tty_register_ldisc(const struct tty_ldisc_ops *new_ldisc);
+void tty_unregister_ldisc(const struct tty_ldisc_ops *ldisc);
 int tty_set_ldisc(struct tty_struct *tty, int disc);
 
 #endif /* _LINUX_TTY_LDISC_H */