Messages in this thread | | | From | "Jason A. Donenfeld" <> | Date | Sat, 5 Feb 2022 14:17:15 +0100 | Subject | Re: [PATCH 1/2] random: fix locking in crng_fast_load() |
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Hi Dominik,
Does this introduce a lock nesting inversion situation?
With your patch, crng_fast_load() now does:
lock(primary_crng) invalidate_batched_entropy() lock(batch_lock) unlock(batch_lock) unlock(primary_crng)
While get_random_{u32,u64}() does:
lock(batch_lock) extract_crng() lock(primary_crng) unlock(primary_crng) unlock(batch_lock)
Is this correct? If so, we might have to defer this patch until after <https://git.kernel.org/pub/scm/linux/kernel/git/crng/random.git/commit/?id=2dfab1b1> or something like it lands, which attempts to get rid of the batched entropy lock.
If that analysis seems right to you, I could pull this patch into that development branch for poking and prodding.
Jason
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