kernel.h: Silence sparse warning in lower_32_bits
authorHerbert Xu <herbert@gondor.apana.org.au>
Fri, 28 Aug 2020 07:11:25 +0000 (17:11 +1000)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 28 Aug 2020 18:21:20 +0000 (11:21 -0700)
I keep getting sparse warnings in crypto such as:

  CHECK   drivers/crypto/ccree/cc_hash.c
   drivers/crypto/ccree/cc_hash.c:49:9: warning: cast truncates bits from constant value (47b5481dbefa4fa4 becomes befa4fa4)
   drivers/crypto/ccree/cc_hash.c:49:26: warning: cast truncates bits from constant value (db0c2e0d64f98fa7 becomes 64f98fa7)
   [.. many more ..]

This patch removes the warning by adding a mask to keep sparse
happy.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/kernel.h

index 500def6..c25b8e4 100644 (file)
  * lower_32_bits - return bits 0-31 of a number
  * @n: the number we're accessing
  */
-#define lower_32_bits(n) ((u32)(n))
+#define lower_32_bits(n) ((u32)((n) & 0xffffffff))
 
 struct completion;
 struct pt_regs;