realtek: dsa: Build check size of drop counter names

The commit 1cfd45ae0bad ("realtek: Add debugfs support for RTL9300") caused
previously an out of bounds access on the array holding the names of drop
counters (and incorrect names in the output) fur RTL839x because of a
missing comma. To avoid such situation in the future, calculate the size of
the array during compilation. And to ensure that this count matches the
actual number of counters in HW, compare this number during compile time
with the expected value.

Suggested-by: Hauke Mehrtens <[email protected]>
Signed-off-by: Sven Eckelmann <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/20905
Signed-off-by: Robert Marko <[email protected]>

diff --git a/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/debugfs.c b/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/debugfs.c
index e95ffc5b0a79415e94f51c99dd649515a228b827..11420c4c4e2b0b83cf52d924839f0707c4386d42 100644 (file)
--- a/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/debugfs.c
+++ b/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/debugfs.c
@@ -205,22 +205,26 @@ static ssize_t drop_counter_read(struct file *filp, char __user *buffer, size_t
        case RTL8380_FAMILY_ID:
                d = rtl838x_drop_cntr;
                offset = RTL838X_STAT_PRVTE_DROP_COUNTERS;
-               num = 40;
+               num = ARRAY_SIZE(rtl838x_drop_cntr);
+               BUILD_BUG_ON(num != 40);
                break;
        case RTL8390_FAMILY_ID:
                d = rtl839x_drop_cntr;
                offset = RTL839X_STAT_PRVTE_DROP_COUNTERS;
-               num = 45;
+               num = ARRAY_SIZE(rtl839x_drop_cntr);
+               BUILD_BUG_ON(num != 45);
                break;
        case RTL9300_FAMILY_ID:
                d = rtl930x_drop_cntr;
                offset = RTL930X_STAT_PRVTE_DROP_COUNTERS;
-               num = 85;
+               num = ARRAY_SIZE(rtl930x_drop_cntr);
+               BUILD_BUG_ON(num != 85);
                break;
        case RTL9310_FAMILY_ID:
                d = rtl931x_drop_cntr;
                offset = RTL931X_STAT_PRVTE_DROP_COUNTERS;
-               num = 81;
+               num = ARRAY_SIZE(rtl931x_drop_cntr);
+               BUILD_BUG_ON(num != 81);
                break;
        }