Commit 1f59342b authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Dmitry Torokhov
Browse files

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: default avatarArnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20210927101416.1569609-1-arnd@kernel.org


Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 5c4c2c8e

drivers/input/joystick/analog.c

+10 −8
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/input.h>

#include <linux/gameport.h>

#include <linux/jiffies.h>

#include <linux/seq_buf.h>

#include <linux/timex.h>

#include <linux/timekeeping.h>
@@ -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");

}



/*