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 <[email protected]> Cc: Peter Hurley <[email protected]> Cc: Alan Cox <[email protected]> --- drivers/tty/tty_io.c | 21 +++++++++++++++++++++ include/uapi/linux/tty_flags.h | 2 ++ 2 files changed, 23 insertions(+) diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 1107398a545c..95f330282046 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2728,6 +2728,24 @@ struct tty_struct *tty_pair_get_pty(struct tty_struct *tty) } EXPORT_SYMBOL(tty_pair_get_pty); +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); +} + /* * Split this up, as gcc can choke on it otherwise.. */ @@ -2859,6 +2877,9 @@ 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); diff --git a/include/uapi/linux/tty_flags.h b/include/uapi/linux/tty_flags.h index eefcb483a2c0..879b91713e7c 100644 --- a/include/uapi/linux/tty_flags.h +++ b/include/uapi/linux/tty_flags.h @@ -59,6 +59,8 @@ #define ASYNC_AUTOPROBE (1U << ASYNCB_AUTOPROBE) #define ASYNC_FLAGS ((1U << (ASYNCB_LAST_USER + 1)) - 1) +#define ASYNC_DEPRECATED (ASYNC_SESSION_LOCKOUT | ASYNC_PGRP_LOCKOUT | \ + ASYNC_CALLOUT_NOHUP | ASYNC_AUTOPROBE) #define ASYNC_USR_MASK (ASYNC_SPD_MASK|ASYNC_CALLOUT_NOHUP| \ ASYNC_LOW_LATENCY) #define ASYNC_SPD_CUST (ASYNC_SPD_HI|ASYNC_SPD_VHI) -- 2.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
