hwrng: core - Clean up RNG list when last hwrng is unregistered

Commit 142a27f0a7 added support for a "best" RNG, and in doing so
introduced a hang from rmmod/modprobe -r when the last RNG on the list
was unloaded.

When the hwrng list is depleted, return the global variables to their
original state and decrement all references to the object.

Fixes: 142a27f0a7 ("hwrng: core - Reset user selected rng by writing "" to rng_current")
Signed-off-by: Gary R Hook <gary.hook@amd.com>
Reviewed-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Gary R Hook 2017-12-15 13:55:59 -06:00 committed by Herbert Xu
parent 871df319bd
commit 0e4b52942b

View File

@ -306,6 +306,10 @@ static int enable_best_rng(void)
ret = ((new_rng == current_rng) ? 0 : set_current_rng(new_rng));
if (!ret)
cur_rng_set_by_user = 0;
} else {
drop_current_rng();
cur_rng_set_by_user = 0;
ret = 0;
}
return ret;