get_random_u32() which is the function in question uses RDRAND if ut is available regardless of what RANDOM_TRUST_CPU says. It is meant of fast source of “good

get_random_u32() which is the function in question uses RDRAND if ut is available regardless of what RANDOM_TRUST_CPU says. It is meant of fast source of “good enough entropy” for short lived secrets. Short circuiting to RDRAND arguably breaks the API contract, but when RDRAND actually produces random-ish values it is probably good enough.