f81ee8b8b8
Make tty_unregister_ldisc symmetric to tty_register_ldisc by accepting struct tty_ldisc_ops as a parameter instead of ldisc number. This avoids checking of the ldisc number bounds in tty_unregister_ldisc. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: William Hubbs <w.d.hubbs@gmail.com> Cc: Chris Brannon <chris@the-brannons.com> Cc: Kirk Reiser <kirk@reisers.ca> Cc: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Wolfgang Grandegger <wg@grandegger.com> Cc: Marc Kleine-Budde <mkl@pengutronix.de> Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Rodolfo Giometti <giometti@enneenne.com> Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Mark Brown <broonie@kernel.org> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Link: https://lore.kernel.org/r/20210505091928.22010-17-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
70 lines
1.3 KiB
C
70 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/types.h>
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#include <linux/errno.h>
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#include <linux/tty.h>
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#include <linux/module.h>
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/*
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* n_null.c - Null line discipline used in the failure path
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*
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* Copyright (C) Intel 2017
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*/
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static int n_null_open(struct tty_struct *tty)
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{
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return 0;
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}
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static void n_null_close(struct tty_struct *tty)
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{
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}
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static ssize_t n_null_read(struct tty_struct *tty, struct file *file,
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unsigned char *buf, size_t nr,
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void **cookie, unsigned long offset)
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{
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return -EOPNOTSUPP;
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}
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static ssize_t n_null_write(struct tty_struct *tty, struct file *file,
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const unsigned char *buf, size_t nr)
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{
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return -EOPNOTSUPP;
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}
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static void n_null_receivebuf(struct tty_struct *tty,
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const unsigned char *cp, const char *fp,
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int cnt)
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{
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}
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static struct tty_ldisc_ops null_ldisc = {
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.owner = THIS_MODULE,
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.num = N_NULL,
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.name = "n_null",
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.open = n_null_open,
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.close = n_null_close,
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.read = n_null_read,
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.write = n_null_write,
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.receive_buf = n_null_receivebuf
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};
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static int __init n_null_init(void)
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{
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BUG_ON(tty_register_ldisc(&null_ldisc));
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return 0;
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}
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static void __exit n_null_exit(void)
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{
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tty_unregister_ldisc(&null_ldisc);
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}
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module_init(n_null_init);
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module_exit(n_null_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Alan Cox");
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MODULE_ALIAS_LDISC(N_NULL);
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MODULE_DESCRIPTION("Null ldisc driver");
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