search for: rng_get_data

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 on...

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 on...

...e *filp, char __user *buf, > goto out_unlock; > } > > + mutex_lock(&reading_mutex); I think this breaks O_NONBLOCK: we have hwrng core thread that is constantly pumps underlying rng for data; the thread takes the mutex and calls rng_get_data() that blocks until RNG responds. This means that even user specified O_NONBLOCK here we'll be waiting until [hwrng] thread releases reading_mutex before we can continue. > if (!data_avail) { > bytes_read = rng_get_data(current_rng, rng_buffer, &gt...

...e *filp, char __user *buf, > goto out_unlock; > } > > + mutex_lock(&reading_mutex); I think this breaks O_NONBLOCK: we have hwrng core thread that is constantly pumps underlying rng for data; the thread takes the mutex and calls rng_get_data() that blocks until RNG responds. This means that even user specified O_NONBLOCK here we'll be waiting until [hwrng] thread releases reading_mutex before we can continue. > if (!data_avail) { > bytes_read = rng_get_data(current_rng, rng_buffer, &gt...

...k; > > > } > > > > > > + mutex_lock(&reading_mutex); > > > > I think this breaks O_NONBLOCK: we have hwrng core thread that is > > constantly pumps underlying rng for data; the thread takes the mutex > > and calls rng_get_data() that blocks until RNG responds. This means > > that even user specified O_NONBLOCK here we'll be waiting until > > [hwrng] thread releases reading_mutex before we can continue. > > I think for 'virtio_rng' for 'O_NON_BLOCK' 'rng_get_data' returns &gt...

...k; > > > } > > > > > > + mutex_lock(&reading_mutex); > > > > I think this breaks O_NONBLOCK: we have hwrng core thread that is > > constantly pumps underlying rng for data; the thread takes the mutex > > and calls rng_get_data() that blocks until RNG responds. This means > > that even user specified O_NONBLOCK here we'll be waiting until > > [hwrng] thread releases reading_mutex before we can continue. > > I think for 'virtio_rng' for 'O_NON_BLOCK' 'rng_get_data' returns &gt...

On Wed, Jul 02, 2014 at 06:56:35PM +0530, Amit Shah wrote: > Hi Jason, > > On (Wed) 02 Jul 2014 [13:00:19], Jason Cooper 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 DRI...

On Wed, Jul 02, 2014 at 06:56:35PM +0530, Amit Shah wrote: > Hi Jason, > > On (Wed) 02 Jul 2014 [13:00:19], Jason Cooper 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 DRI...

v2: - this now separates both the patches; the virtio-rng fix is self-contained - re-work hwrng core to fetch randomness at device init time if ->init() is registered by the device, instead of not calling it at all. - virtio-rng: introduce a probe_done bool to ensure we don't ask host for data before successful probe Hi, When booting a recent kernel under KVM with the virtio-rng

v2: - this now separates both the patches; the virtio-rng fix is self-contained - re-work hwrng core to fetch randomness at device init time if ->init() is registered by the device, instead of not calling it at all. - virtio-rng: introduce a probe_done bool to ensure we don't ask host for data before successful probe Hi, When booting a recent kernel under KVM with the virtio-rng

On Fri, Jul 4, 2014 at 10:34 PM, Amit Shah <amit.shah at redhat.com> 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. > > 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 cal...

On Fri, Jul 4, 2014 at 10:34 PM, Amit Shah <amit.shah at redhat.com> 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. > > 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 cal...

Hi, When booting a recent kernel under KVM with the virtio-rng device enabled, the boot process was stalling. Bisect pointed to a commit made during the 3.15 window to fetch randomness from newly-registered devices in the hwrng core. The details are in the patches. I considered a couple of approaches, but basing on the init() function being registered, as is done in patch 1 here, seems like

Hi, When booting a recent kernel under KVM with the virtio-rng device enabled, the boot process was stalling. Bisect pointed to a commit made during the 3.15 window to fetch randomness from newly-registered devices in the hwrng core. The details are in the patches. I considered a couple of approaches, but basing on the init() function being registered, as is done in patch 1 here, seems like

On Sat, Jul 05, 2014 at 11:04:52AM +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. > > 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 ca...

On Sat, Jul 05, 2014 at 11:04:52AM +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. > > 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 ca...

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, whic...

...Cooper wrote: > On Wed, Jul 02, 2014 at 06:56:35PM +0530, Amit Shah wrote: > > Hi Jason, > > > > On (Wed) 02 Jul 2014 [13:00:19], Jason Cooper 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...

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. 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 is made after device init....

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. 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 is made after device init....