4.4-stable review patch. If anyone has any objections, please let me know.
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From: Wentao Wang witallwang@gmail.com
commit 3ec8002951ea173e24b466df1ea98c56b7920e63 upstream.
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(-)
--- 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;