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![Paul Burton](https://secure.gravatar.com/avatar/71b58ecb349ed3cb25b477c9a9347323.jpg?s=96&d=mm)
Paul Burton committed e6331a321aa
MIPS: KVM: Use prandom_u32_max() to generate tlbwr index Emulation of the tlbwr instruction, which writes a TLB entry to a random index in the TLB, currently uses get_random_bytes() to generate a 4 byte random number which we then mask to form the index. This is overkill in a couple of ways: - We don't need 4 bytes here since we mask the value to form a 6 bit number anyway, so we waste /dev/random entropy generating 3 random bytes that are unused. - We don't need crypto-grade randomness here - the architecture spec allows implementations to use any algorithm & merely encourages that some pseudo-randomness be used rather than a simple counter. The fast prandom_u32() function fits that criteria well. So rather than using get_random_bytes() & consuming /dev/random entropy, switch to using the faster prandom_u32_max() which provides what we need here whilst also performing the masking/modulo for us. Signed-off-by: Paul Burton <paul.burton@mips.com> Reported-by: George Spelvin <lkml@sdf.org> Cc: James Hogan <jhogan@kernel.org> Cc: linux-mips@vger.kernel.org