The driver causes a warning when built as big-endian: drivers/crypto/ccp/ccp-dev-v5.c: In function 'ccp5_perform_des3': include/uapi/linux/byteorder/big_endian.h:32:26: error: large integer implicitly truncated to unsigned type [-Werror=overflow] #define __cpu_to_le32(x) ((__force __le32)__swab32((x))) ^ include/linux/byteorder/generic.h:87:21: note: in expansion of macro '__cpu_to_le32' #define cpu_to_le32 __cpu_to_le32 ^~~~~~~~~~~~~ drivers/crypto/ccp/ccp-dev-v5.c:436:28: note: in expansion of macro 'cpu_to_le32' CCP5_CMD_KEY_MEM(&desc) = cpu_to_le32(CCP_MEMTYPE_SB); The warning is correct, doing a 32-bit byte swap on a value that gets assigned into a bit field cannot work, since we would only write zeroes in this case, regardless of the input. In fact, the use of bit fields in hardware defined data structures is not portable to start with, so until all these bit fields get replaced by something else, the driver cannot work on big-endian machines, and I'm adding an annotation here to prevent it from being selected. The CCPv3 code seems to not suffer from this problem, only v5 uses bitfields. Fixes: 4b394a232df7 ("crypto: ccp - Let a v5 CCP provide the same function as v3") Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- drivers/crypto/ccp/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/crypto/ccp/Kconfig b/drivers/crypto/ccp/Kconfig index 2238f77aa248..07af9ece84f9 100644 --- a/drivers/crypto/ccp/Kconfig +++ b/drivers/crypto/ccp/Kconfig @@ -1,6 +1,7 @@ config CRYPTO_DEV_CCP_DD tristate "Cryptographic Coprocessor device driver" depends on CRYPTO_DEV_CCP + depends on !CPU_BIG_ENDIAN || BROKEN default m select HW_RANDOM select DMA_ENGINE -- 2.9.0