From: Johan Hovold johan@kernel.org

stable inclusion from stable-v4.19.191 commit 76d7fc0857bc4033415fcad905db13753d0febc7 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I926JG CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ Upstream commit 1b8b20868a6d64cfe8174a21b25b74367bdf0560 ]

Drivers should return -ENOTTY ("Inappropriate I/O control operation") when an ioctl isn't supported, while -EINVAL is used for invalid arguments.

Fix up the TIOCMGET, TIOCMSET and TIOCGICOUNT helpers which returned -EINVAL when a tty driver did not implement the corresponding operations.

Note that the TIOCMGET and TIOCMSET helpers predate git and do not get a corresponding Fixes tag below.

Fixes: d281da7ff6f7 ("tty: Make tiocgicount a handler") Signed-off-by: Johan Hovold johan@kernel.org Link: https://lore.kernel.org/r/20210407095208.31838-3-johan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yi Yang yiyang13@huawei.com --- drivers/tty/tty_io.c | 8 ++++---- include/linux/tty_driver.h | 2 +- 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 58c3f7b92b0d..908c331c5760 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2441,14 +2441,14 @@ static int send_break(struct tty_struct *tty, unsigned int duration) * @p: pointer to result * * Obtain the modem status bits from the tty driver if the feature - * is supported. Return -EINVAL if it is not available. + * is supported. Return -ENOTTY if it is not available. * * Locking: none (up to the driver) */

static int tty_tiocmget(struct tty_struct *tty, int __user *p) { - int retval = -EINVAL; + int retval = -ENOTTY;

if (tty->ops->tiocmget) { retval = tty->ops->tiocmget(tty); @@ -2466,7 +2466,7 @@ static int tty_tiocmget(struct tty_struct *tty, int __user *p) * @p: pointer to desired bits * * Set the modem status bits from the tty driver if the feature - * is supported. Return -EINVAL if it is not available. + * is supported. Return -ENOTTY if it is not available. * * Locking: none (up to the driver) */ @@ -2478,7 +2478,7 @@ static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, unsigned int set, clear, val;

if (tty->ops->tiocmset == NULL) - return -EINVAL; + return -ENOTTY;

retval = get_user(val, p); if (retval) diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h index 71dbc891851a..e10b09672345 100644 --- a/include/linux/tty_driver.h +++ b/include/linux/tty_driver.h @@ -236,7 +236,7 @@ * * Called when the device receives a TIOCGICOUNT ioctl. Passed a kernel * structure to complete. This method is optional and will only be called - * if provided (otherwise EINVAL will be returned). + * if provided (otherwise ENOTTY will be returned). */

#include <linux/export.h>