driver: rng: Fix SMCCC TRNG crash

Fix a SMCCC TRNG null pointer crash due to a failed smccc feature
binding.

Fixes: 53355bb86c25 ("drivers: rng: add smccc trng driver")
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Weizhao Ouyang <o451686892@gmail.com>

diff --git a/drivers/rng/smccc_trng.c b/drivers/rng/smccc_trng.c
index 5bb7ebe8a497620b99e521dea30cbea0548f99c7..f59b80666b330a4ee182887dafb256f9b2feb962 100644 (file)
--- a/drivers/rng/smccc_trng.c
+++ b/drivers/rng/smccc_trng.c
@@ -165,7 +165,7 @@ static int smccc_trng_probe(struct udevice *dev)
        struct smccc_trng_priv *priv = dev_get_priv(dev);
        struct arm_smccc_res res;
 
-       if (!(smccc_trng_is_supported(smccc->invoke_fn)))
+       if (!smccc || !(smccc_trng_is_supported(smccc->invoke_fn)))
                return -ENODEV;
 
        /* At least one of 64bit and 32bit interfaces is available */