This is a note to let you know that I've just added the patch titled

Disable kgdboc failed by echo space to

to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From d70fc79f67c7030fa35d2e1617a02eae6cafb454 Mon Sep 17 00:00:00 2001

From: Wentao Wang witallwang@gmail.com Date: Wed, 20 Mar 2019 15:30:39 +0000 Subject: Disable kgdboc failed by echo space to /sys/module/kgdboc/parameters/kgdboc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

Echo "" to /sys/module/kgdboc/parameters/kgdboc will fail with "No such device” error.

This is caused by function "configure_kgdboc" who init err to ENODEV when the config is empty (legal input) the code go out with ENODEV returned.

Fixes: 2dd453168643 ("kgdboc: Fix restrict error") Signed-off-by: Wentao Wang witallwang@gmail.com Cc: stable stable@vger.kernel.org Acked-by: Daniel Thompson daniel.thompson@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/tty/serial/kgdboc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c index 6fb312e7af71..bfe5e9e034ec 100644 --- a/drivers/tty/serial/kgdboc.c +++ b/drivers/tty/serial/kgdboc.c @@ -148,8 +148,10 @@ static int configure_kgdboc(void) char *cptr = config; struct console *cons;

- if (!strlen(config) || isspace(config[0])) + if (!strlen(config) || isspace(config[0])) { + err = 0; goto noconfig; + }

kgdboc_io_ops.is_console = 0; kgdb_tty_driver = NULL;