[PATCH mips-next 3/3] MIPS: checksum: fix sparse flooding on asm/checksum.h

From: Alexander Lobakin
Date: Sat Jun 20 2020 - 05:35:19 EST


csum_fold() in MIPS' asm/checksum.h is another source of sparse flooding
when building different networking source code.
The thing is that only half of __wsum <--> u32 casts inside the funtion
is forced, which is insufficient.
Add all necessary forced typecasting to stop floods and simplify actual
bug hunting.

Signed-off-by: Alexander Lobakin <alobakin@xxxxx>
---
arch/mips/include/asm/checksum.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/mips/include/asm/checksum.h b/arch/mips/include/asm/checksum.h
index dcebaaf8c862..181f7d14efb9 100644
--- a/arch/mips/include/asm/checksum.h
+++ b/arch/mips/include/asm/checksum.h
@@ -113,9 +113,9 @@ static inline __sum16 csum_fold(__wsum csum)
u32 sum = (__force u32)csum;

sum += (sum << 16);
- csum = (sum < csum);
+ csum = (__force __wsum)(sum < (__force u32)csum);
sum >>= 16;
- sum += csum;
+ sum += (__force u32)csum;

return (__force __sum16)~sum;
}
--
2.27.0