[ Upstream commit eaecce12f5f0d2c35d278e41e1bc4522393861ab ]
When unloading omap3-rom-rng, we'll get the following:
WARNING: CPU: 0 PID: 100 at drivers/clk/clk.c:948 clk_core_disable
This is because the clock may be already disabled by omap3_rom_rng_idle().
Let's fix the issue by checking for rng_idle on exit.
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Adam Ford <aford173@gmail.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Tero Kristo <t-kristo@ti.com>
Fixes: 1c6b7c2108bd ("hwrng: OMAP3 ROM Random Number Generator support")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit af0d4442dd6813de6e77309063beb064fa8e89ae upstream.
No remove function implemented yet in the driver.
Without remove function, the pm_runtime implementation
complains when removing and probing again the driver.
Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 78887832e76541f77169a24ac238fccb51059b63 upstream.
add_early_randomness() is called by hwrng_register() when the
hardware is added. If this hardware and its module are present
at boot, and if there is no data available the boot hangs until
data are available and can't be interrupted.
For instance, in the case of virtio-rng, in some cases the host can be
not able to provide enough entropy for all the guests.
We can have two easy ways to reproduce the problem but they rely on
misconfiguration of the hypervisor or the egd daemon:
- if virtio-rng device is configured to connect to the egd daemon of the
host but when the virtio-rng driver asks for data the daemon is not
connected,
- if virtio-rng device is configured to connect to the egd daemon of the
host but the egd daemon doesn't provide data.
The guest kernel will hang at boot until the virtio-rng driver provides
enough data.
To avoid that, call rng_get_data() in non-blocking mode (wait=0)
from add_early_randomness().
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Fixes: d9e797261933 ("hwrng: add randomness to system from rng...")
Cc: <stable@vger.kernel.org>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit aef027db48da56b6f25d0e54c07c8401ada6ce21 ]
The virtio-rng driver uses a completion called have_data to wait for a
virtio read to be fulfilled by the hypervisor. The completion is reset
before placing a buffer on the virtio queue and completed by the virtio
callback once data has been written into the buffer.
Prior to this commit, the driver called init_completion on this
completion both during probe as well as when registering virtio buffers
as part of a hwrng read operation. The second of these init_completion
calls should instead be reinit_completion because the have_data
completion has already been inited by probe. As described in
Documentation/scheduler/completion.txt, "Calling init_completion() twice
on the same completion object is most likely a bug".
This bug was present in the initial implementation of virtio-rng in
f7f510ec1957 ("virtio: An entropy device, as suggested by hpa"). Back
then the have_data completion was a single static completion rather than
a member of one of potentially multiple virtrng_info structs as
implemented later by 08e53fbdb85c ("virtio-rng: support multiple
virtio-rng devices"). The original driver incorrectly used
init_completion rather than INIT_COMPLETION to reset have_data during
read.
Tested by running `head -c48 /dev/random | hexdump` within crosvm, the
Chrome OS virtual machine monitor, and confirming that the virtio-rng
driver successfully produces random bytes from the host.
Signed-off-by: David Tolnay <dtolnay@gmail.com>
Tested-by: David Tolnay <dtolnay@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
