[PATCH v3] Input: sidewinder - use scnprintf() for the port names

[xujiahao]

sw_connect() composes the physical path of each port as "%s/input%d"
from gameport->phys into a 32-byte array, and sw_3dp_id() builds
" [PnP %d.%02d id %s rev %s]" into the 40-byte comment buffer of
sw_connect().  GCC reports that both formats can overflow their buffers
in a W=1 build:

  drivers/input/joystick/sidewinder.c:538:58: warning: '%s' directive output may be truncated writing up to 8 bytes into a region of size between 5 and 21 [-Wformat-truncation=]
  drivers/input/joystick/sidewinder.c:727:29: warning: '/input' directive output may be truncated writing 6 bytes into a region of size between 1 and 32 [-Wformat-truncation=]

The values seen in practice fit these buffers, and a truncated name is
harmless, so keep the sizes as they are and switch to scnprintf() to
make the truncation explicit instead of letting the compiler warn about
a possible one.

Link: https://lore.kernel.org/all/20261106033300.3439313-1-xujiahao@xxxxxxxxxxxxxxxxxxxx/
Suggested-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202611091814.ChpgVgpE-lkp@xxxxxxxxx/
Closes: https://lore.kernel.org/oe-kbuild-all/202611100328.QAelfSpD-lkp@xxxxxxxxx/
Signed-off-by: xujiahao <xujiahao@xxxxxxxxxxxxxxxxxxxx>
---
v3:
 - The PnP id computation is untouched again.  v2 moved the (int) cast
   behind the division, which made it a 64-bit division and broke 32-bit
   builds (ld: undefined reference to __aeabi_uldivmod / __udivdi3 /
   __umoddi3), as reported by the kernel test robot.  Only the snprintf()
   calls change now.
---
 drivers/input/joystick/sidewinder.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/input/joystick/sidewinder.c b/drivers/input/joystick/sidewinder.c
index 7f37d18c8..78dc70964 100644
--- a/drivers/input/joystick/sidewinder.c
+++ b/drivers/input/joystick/sidewinder.c
@@ -535,12 +535,12 @@ static void sw_3dp_id(unsigned char *buf, char *comment, size_t size)
 
 	pnp[7] = rev[8] = 0;
 
-	snprintf(comment, size, " [PnP %d.%02d id %s rev %s]",
-		(int) ((sw_get_bits(buf, 8, 6, 1) << 6) |		/* Two 6-bit values */
+	scnprintf(comment, size, " [PnP %d.%02d id %s rev %s]",
+		  (int)((sw_get_bits(buf, 8, 6, 1) << 6) |	/* Two 6-bit values */
 			sw_get_bits(buf, 16, 6, 1)) / 100,
-		(int) ((sw_get_bits(buf, 8, 6, 1) << 6) |
+		  (int)((sw_get_bits(buf, 8, 6, 1) << 6) |
 			sw_get_bits(buf, 16, 6, 1)) % 100,
-		 pnp, rev);
+		  pnp, rev);
 }
 
 /*
@@ -723,8 +723,8 @@ static int sw_connect(struct gameport *gameport, struct gameport_driver *drv)
 
 		snprintf(sw->name, sizeof(sw->name),
 			 "Microsoft SideWinder %s", sw_name[sw->type]);
-		snprintf(sw->phys[i], sizeof(sw->phys[i]),
-			 "%s/input%d", gameport->phys, i);
+		scnprintf(sw->phys[i], sizeof(sw->phys[i]),
+			  "%s/input%d", gameport->phys, i);
 
 		sw->dev[i] = input_dev = input_allocate_device();
 		if (!input_dev) {
-- 
2.43.0