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hwrng: move some code out mutex_lock for avoiding underlying deadlock

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In next patch, we use reference counting for each struct hwrng,
changing reference count also needs to take mutex_lock. Before
releasing the lock, if we try to stop a kthread that waits to
take the lock to reduce the referencing count, deadlock will
occur.

Signed-off-by: Amos Kong <akong@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Amos Kong
2014-12-08 16:50:36 +08:00
committed by Herbert Xu
parent 9372b35e11
commit 1dacb395d6
1 changed files with 3 additions and 3 deletions
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6
drivers/char/hw_random/core.c
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@@ -470,12 +470,12 @@ void hwrng_unregister(struct hwrng *rng)
} }
} }
if (list_empty(&rng_list)) { if (list_empty(&rng_list)) {
mutex_unlock(&rng_mutex);
unregister_miscdev(); unregister_miscdev();
if (hwrng_fill) if (hwrng_fill)
kthread_stop(hwrng_fill); kthread_stop(hwrng_fill);
} } else
mutex_unlock(&rng_mutex);
mutex_unlock(&rng_mutex);
} }
EXPORT_SYMBOL_GPL(hwrng_unregister); EXPORT_SYMBOL_GPL(hwrng_unregister);