mm/damon/sysfs: eliminate potential uninitialized variable warning

[platform/kernel/linux-starfive.git] / block / blk-throttle.c

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 38a881c..13e4377 100644 (file)
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -723,6 +723,12 @@ static unsigned int calculate_io_allowed(u32 iops_limit,
 
 static u64 calculate_bytes_allowed(u64 bps_limit, unsigned long jiffy_elapsed)
 {
+       /*
+        * Can result be wider than 64 bits?
+        * We check against 62, not 64, due to ilog2 truncation.
+        */
+       if (ilog2(bps_limit) + ilog2(jiffy_elapsed) - ilog2(HZ) > 62)
+               return U64_MAX;
        return mul_u64_u64_div_u64(bps_limit, (u64)jiffy_elapsed, (u64)HZ);
 }