From: James Cowgill james.cowgill@blaize.com
[ Upstream commit 042b4b169c6fb9d4df268d66282d7302dd73d37b ]
The SMCCC_RET_TRNG_NO_ENTROPY switch arm is never used because the NO_ENTROPY return value is negative and negative values are handled above the switch by immediately returning.
Fix by handling errors using a default arm in the switch.
Fixes: 0888d04b47a1 ("hwrng: Add Arm SMCCC TRNG based driver") Signed-off-by: James Cowgill james.cowgill@blaize.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/char/hw_random/arm_smccc_trng.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/char/hw_random/arm_smccc_trng.c b/drivers/char/hw_random/arm_smccc_trng.c index b24ac39a903b..e34c3ea692b6 100644 --- a/drivers/char/hw_random/arm_smccc_trng.c +++ b/drivers/char/hw_random/arm_smccc_trng.c @@ -71,8 +71,6 @@ static int smccc_trng_read(struct hwrng *rng, void *data, size_t max, bool wait) MAX_BITS_PER_CALL);
arm_smccc_1_1_invoke(ARM_SMCCC_TRNG_RND, bits, &res); - if ((int)res.a0 < 0) - return (int)res.a0;
switch ((int)res.a0) { case SMCCC_RET_SUCCESS: @@ -88,6 +86,8 @@ static int smccc_trng_read(struct hwrng *rng, void *data, size_t max, bool wait) return copied; cond_resched(); break; + default: + return -EIO; } }