On Wed, Jul 02, 2014 at 03:58:15PM +0530, Amit Shah wrote: > Commit d9e7972619334 "hwrng: add randomness to system from rng sources" > added a call to rng_get_data() from the hwrng_register() function. > However, some rng devices need initialization before data can be read > from them. > > Also, the virtio-rng device does not behave properly when this call is > made in its probe() routine - the virtio core sets the DRIVER_OK status > bit only on a successful probe, which means the host ignores all > communication from the guest, and the guest insmod or boot process just > sits there doing nothing. > > This commit makes the call to rng_get_data() depend on no init fn > pointer being registered by the device. If an init function is > registered, this call isn't made. > > CC: Kees Cook <[email protected]> > CC: Jason Cooper <[email protected]> > CC: Herbert Xu <[email protected]> > CC: <[email protected]> # For 3.15 only
# v3.15+ should be fine here. > Signed-off-by: Amit Shah <[email protected]> > --- > drivers/char/hw_random/core.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c > index 334601c..3f3941d 100644 > --- a/drivers/char/hw_random/core.c > +++ b/drivers/char/hw_random/core.c > @@ -347,9 +347,11 @@ int hwrng_register(struct hwrng *rng) > INIT_LIST_HEAD(&rng->list); > list_add_tail(&rng->list, &rng_list); > > - bytes_read = rng_get_data(rng, bytes, sizeof(bytes), 1); > - if (bytes_read > 0) > - add_device_randomness(bytes, bytes_read); > + if (!rng->init) { > + bytes_read = rng_get_data(rng, bytes, sizeof(bytes), 1); > + if (bytes_read > 0) > + add_device_randomness(bytes, bytes_read); > + } afaict, this is redundant at initialization time. current_rng shouldn't be set yet, so hwrng_init(rng) will get called at line 333. Or, am I missing something? thx, Jason. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
