This is a note to let you know that I've just added the patch titled hwrng: arm-smccc-trng - fix NO_ENTROPY handling to the 6.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: hwrng-arm-smccc-trng-fix-no_entropy-handling.patch and it can be found in the queue-6.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 9c52effa02ba06cb6246e0f09614e1e726804243 Author: James Cowgill <james.cowgill@xxxxxxxxxx> Date: Mon Aug 1 20:04:18 2022 +0000 hwrng: arm-smccc-trng - fix NO_ENTROPY handling [ 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@xxxxxxxxxx> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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; } }