From 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 12:05:51 +0200 Subject: Adding upstream version 5.10.209. Signed-off-by: Daniel Baumann --- drivers/tty/n_null.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 drivers/tty/n_null.c (limited to 'drivers/tty/n_null.c') diff --git a/drivers/tty/n_null.c b/drivers/tty/n_null.c new file mode 100644 index 000000000..ce03ae78f --- /dev/null +++ b/drivers/tty/n_null.c @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include + +/* + * n_null.c - Null line discipline used in the failure path + * + * Copyright (C) Intel 2017 + */ + +static int n_null_open(struct tty_struct *tty) +{ + return 0; +} + +static void n_null_close(struct tty_struct *tty) +{ +} + +static ssize_t n_null_read(struct tty_struct *tty, struct file *file, + unsigned char *buf, size_t nr, + void **cookie, unsigned long offset) +{ + return -EOPNOTSUPP; +} + +static ssize_t n_null_write(struct tty_struct *tty, struct file *file, + const unsigned char *buf, size_t nr) +{ + return -EOPNOTSUPP; +} + +static void n_null_receivebuf(struct tty_struct *tty, + const unsigned char *cp, char *fp, + int cnt) +{ +} + +static struct tty_ldisc_ops null_ldisc = { + .owner = THIS_MODULE, + .magic = TTY_LDISC_MAGIC, + .name = "n_null", + .open = n_null_open, + .close = n_null_close, + .read = n_null_read, + .write = n_null_write, + .receive_buf = n_null_receivebuf +}; + +static int __init n_null_init(void) +{ + BUG_ON(tty_register_ldisc(N_NULL, &null_ldisc)); + return 0; +} + +static void __exit n_null_exit(void) +{ + tty_unregister_ldisc(N_NULL); +} + +module_init(n_null_init); +module_exit(n_null_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Alan Cox"); +MODULE_ALIAS_LDISC(N_NULL); +MODULE_DESCRIPTION("Null ldisc driver"); -- cgit v1.2.3