Hi Jason, thanks for splitting this change out of my other patch. You can add my Signed-off-by, but I'd like to suggest rewriting the commit message as follows (please modify as needed): In case a hwrng source does not provide (trusted) entropy, it cannot assist in initializing the CRNG. Therefore, in case add_hwgenerator_randomness() is called with the entropy parameter set to zero, go to sleep until one reseed interval has passed. While the hwrng thread currently only runs under conditions where this is non-zero, this change is not harmful and prepares for future updates to the hwrng core. Thanks, Dominik Am Tue, Sep 20, 2022 at 04:14:38PM +0200 schrieb Jason A. Donenfeld: > This value is currently never set to zero, because the hwrng thread only > runs if it's going to be non-zero. This is an oversight, however, that > Dominik is working on fixing. In preparation for this, and so that > there's less coordination required between my tree and Herbert's, make > this currently useless, but not harmful, change here now, in hopes that > Dominik can make the corresponding change in the hwrng core later. > > Cc: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> > Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> > Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx> > --- > drivers/char/random.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/char/random.c b/drivers/char/random.c > index 16e0c5f6cf2f..520a385c7dab 100644 > --- a/drivers/char/random.c > +++ b/drivers/char/random.c > @@ -865,9 +865,9 @@ void add_hwgenerator_randomness(const void *buf, size_t len, size_t entropy) > > /* > * Throttle writing to once every reseed interval, unless we're not yet > - * initialized. > + * initialized or no entropy is credited. > */ > - if (!kthread_should_stop() && crng_ready()) > + if (!kthread_should_stop() && (crng_ready() || !entropy)) > schedule_timeout_interruptible(crng_reseed_interval()); > } > EXPORT_SYMBOL_GPL(add_hwgenerator_randomness); > -- > 2.37.3 >
