media: ir-kbd-i2c: change the if logic to avoid a warning
authorMauro Carvalho Chehab <mchehab@s-opensource.com>
Fri, 23 Mar 2018 11:13:06 +0000 (07:13 -0400)
committerMauro Carvalho Chehab <mchehab@s-opensource.com>
Fri, 23 Mar 2018 11:14:47 +0000 (07:14 -0400)
While the code is correct, it produces this warning:
drivers/media/i2c/ir-kbd-i2c.c:593 zilog_ir_format() error: buffer overflow 'code_block->codes' 61 <= 173

As static analyzers may be tricked by arithmetic expressions on
comparisions. So, change the order, in order to shut up this
false-positive warning.

That also makes easier for humans to understand that it won't
be trying to go past buffer size.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
drivers/media/i2c/ir-kbd-i2c.c

index 1d11aab1817a446b928c7ad68b440c4fad5a3321..a7e23bcf845c321d91f6ec40906f81fb4bb6677a 100644 (file)
@@ -583,7 +583,7 @@ static int zilog_ir_format(struct rc_dev *rcdev, unsigned int *txbuf,
                /* first copy any leading non-repeating */
                int leading = c - rep * 3;
 
-               if (leading + rep >= ARRAY_SIZE(code_block->codes) - 3) {
+               if (leading >= ARRAY_SIZE(code_block->codes) - 3 - rep) {
                        dev_warn(&rcdev->dev, "IR too long, cannot transmit\n");
                        return -EINVAL;
                }