media: vivid: avoid integer overflow

Fixes these compiler warnings:

drivers/media/test-drivers/vivid/vivid-rds-gen.c: In function 'vivid_rds_gen_fill':
drivers/media/test-drivers/vivid/vivid-rds-gen.c:147:56: warning: '.' directive output may be truncated writing 1 byte into a region of size between 0 and 3 [-Wformat-truncation=]
  147 |         snprintf(rds->psname, sizeof(rds->psname), "%6d.%1d",
      |                                                        ^
drivers/media/test-drivers/vivid/vivid-rds-gen.c:147:52: note: directive argument in the range [0, 9]
  147 |         snprintf(rds->psname, sizeof(rds->psname), "%6d.%1d",
      |                                                    ^~~~~~~~~
drivers/media/test-drivers/vivid/vivid-rds-gen.c:147:9: note: 'snprintf' output between 9 and 12 bytes into a destination of size 9
  147 |         snprintf(rds->psname, sizeof(rds->psname), "%6d.%1d",
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  148 |                  freq / 16, ((freq & 0xf) * 10) / 16);
      |                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/drivers/media/test-drivers/vivid/vivid-rds-gen.c b/drivers/media/test-drivers/vivid/vivid-rds-gen.c
index b5b104ee64c99f4ba31d07ecb96b62ed64d815cb..c57771119a34b0f6cd50e863239e24c9730c12fd 100644 (file)
--- a/drivers/media/test-drivers/vivid/vivid-rds-gen.c
+++ b/drivers/media/test-drivers/vivid/vivid-rds-gen.c
@@ -145,7 +145,7 @@ void vivid_rds_gen_fill(struct vivid_rds_gen *rds, unsigned freq,
        rds->ta = alt;
        rds->ms = true;
        snprintf(rds->psname, sizeof(rds->psname), "%6d.%1d",
-                freq / 16, ((freq & 0xf) * 10) / 16);
+                (freq / 16) % 1000000, (((freq & 0xf) * 10) / 16) % 10);
        if (alt)
                strscpy(rds->radiotext,
                        " The Radio Data System can switch between different Radio Texts ",