diff options
| author | Jiri Slaby <jslaby@suse.cz> | 2014-11-06 16:56:33 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-06 15:01:03 -0800 |
| commit | 8a8ae62f8296760a2a1eee7009a1444c327603e0 (patch) | |
| tree | e21ad0bbc78ba6cfba450660c23ccaed1198a2b6 /drivers/tty/tty_io.c | |
| parent | d7685ca7c4f5d22dd9b045992e82c1c444a92187 (diff) | |
tty: warn on deprecated serial flags
When somebody calls TIOCSSERIAL ioctl with serial flags to set one of
* ASYNC_SESSION_LOCKOUT
* ASYNC_PGRP_LOCKOUT
* ASYNC_CALLOUT_NOHUP
* ASYNC_AUTOPROBE
nothing happens. We actually ignore the flags for over a decade at
least (I checked 2.6.0).
So start yelling at users who use those flags, that they shouldn't.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/tty_io.c')
| -rw-r--r-- | drivers/tty/tty_io.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 01d45fd7d359..705885891b87 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2760,6 +2760,24 @@ static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) return 0; } +static void tty_warn_deprecated_flags(struct serial_struct __user *ss) +{ + static DEFINE_RATELIMIT_STATE(depr_flags, + DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + char comm[TASK_COMM_LEN]; + int flags; + + if (get_user(flags, &ss->flags)) + return; + + flags &= ASYNC_DEPRECATED; + + if (flags && __ratelimit(&depr_flags)) + pr_warning("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", + __func__, get_task_comm(comm, current), flags); +} + /* * if pty, return the slave side (real_tty) * otherwise, return self @@ -2903,6 +2921,9 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) break; } break; + case TIOCSSERIAL: + tty_warn_deprecated_flags(p); + break; } if (tty->ops->ioctl) { retval = tty->ops->ioctl(tty, cmd, arg); |