From 1f59342be6c075a9520679981c4cfd08bb26c659 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 5 Oct 2021 13:27:26 -0700 Subject: Input: analog - fix invalid snprintf() call Overlapping input and output arguments to snprintf() are undefined behavior in C99: drivers/input/joystick/analog.c: In function 'analog_name': drivers/input/joystick/analog.c:428:3: error: 'snprintf' argument 4 overlaps destination object 'analog' [-Werror=restrict] 428 | snprintf(analog->name, sizeof(analog->name), "%s %d-hat", | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 429 | analog->name, hweight16(analog->mask & ANALOG_HATS_ALL)); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/input/joystick/analog.c:420:40: note: destination object referenced by 'restrict'-qualified argument 1 was declared here 420 | static void analog_name(struct analog *analog) | ~~~~~~~~~~~~~~~^~~~~~ Change this function to use the simpler seq_buf interface instead. Signed-off-by: Arnd Bergmann Link: https://lore.kernel.org/r/20210927101416.1569609-1-arnd@kernel.org Signed-off-by: Dmitry Torokhov --- drivers/input/joystick/analog.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/input/joystick/analog.c b/drivers/input/joystick/analog.c index f798922a4598..d9f866ffde6b 100644 --- a/drivers/input/joystick/analog.c +++ b/drivers/input/joystick/analog.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include @@ -419,23 +420,24 @@ static void analog_calibrate_timer(struct analog_port *port) static void analog_name(struct analog *analog) { - snprintf(analog->name, sizeof(analog->name), "Analog %d-axis %d-button", + struct seq_buf s; + + seq_buf_init(&s, analog->name, sizeof(analog->name)); + seq_buf_printf(&s, "Analog %d-axis %d-button", hweight8(analog->mask & ANALOG_AXES_STD), hweight8(analog->mask & ANALOG_BTNS_STD) + !!(analog->mask & ANALOG_BTNS_CHF) * 2 + hweight16(analog->mask & ANALOG_BTNS_GAMEPAD) + !!(analog->mask & ANALOG_HBTN_CHF) * 4); if (analog->mask & ANALOG_HATS_ALL) - snprintf(analog->name, sizeof(analog->name), "%s %d-hat", - analog->name, hweight16(analog->mask & ANALOG_HATS_ALL)); + seq_buf_printf(&s, " %d-hat", + hweight16(analog->mask & ANALOG_HATS_ALL)); if (analog->mask & ANALOG_HAT_FCS) - strlcat(analog->name, " FCS", sizeof(analog->name)); + seq_buf_printf(&s, " FCS"); if (analog->mask & ANALOG_ANY_CHF) - strlcat(analog->name, (analog->mask & ANALOG_SAITEK) ? " Saitek" : " CHF", - sizeof(analog->name)); + seq_buf_printf(&s, (analog->mask & ANALOG_SAITEK) ? " Saitek" : " CHF"); - strlcat(analog->name, (analog->mask & ANALOG_GAMEPAD) ? " gamepad": " joystick", - sizeof(analog->name)); + seq_buf_printf(&s, (analog->mask & ANALOG_GAMEPAD) ? " gamepad" : " joystick"); } /* -- cgit v1.2.3