3.15-stable patches

added patches:
	hwrng-virtio-ensure-reads-happen-after-successful-probe.patch

diff --git a/queue-3.15/hwrng-virtio-ensure-reads-happen-after-successful-probe.patch b/queue-3.15/hwrng-virtio-ensure-reads-happen-after-successful-probe.patch
new file mode 100644 (file)
index 0000000..4bdd63c
--- /dev/null
+++ b/queue-3.15/hwrng-virtio-ensure-reads-happen-after-successful-probe.patch
@@ -0,0 +1,78 @@
+From e052dbf554610e2104c5a7518c4d8374bed701bb Mon Sep 17 00:00:00 2001
+From: Amit Shah <amit.shah@redhat.com>
+Date: Thu, 10 Jul 2014 15:42:35 +0530
+Subject: hwrng: virtio - ensure reads happen after successful probe
+
+From: Amit Shah <amit.shah@redhat.com>
+
+commit e052dbf554610e2104c5a7518c4d8374bed701bb upstream.
+
+The hwrng core asks for random data in the hwrng_register() call itself
+from commit d9e7972619.  This doesn't play well with virtio -- the
+DRIVER_OK bit is only set by virtio core on a successful probe, and
+we're not yet out of our probe routine when this call is made.  This
+causes the host to not acknowledge any requests we put in the virtqueue,
+and the insmod or kernel boot process just waits for data to arrive from
+the host, which never happens.
+
+CC: Kees Cook <keescook@chromium.org>
+CC: Jason Cooper <jason@lakedaemon.net>
+CC: Herbert Xu <herbert@gondor.apana.org.au>
+Reviewed-by: Jason Cooper <jason@lakedaemon.net>
+Signed-off-by: Amit Shah <amit.shah@redhat.com>
+Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/char/hw_random/core.c       |    6 ++++++
+ drivers/char/hw_random/virtio-rng.c |   10 ++++++++++
+ 2 files changed, 16 insertions(+)
+
+--- a/drivers/char/hw_random/core.c
++++ b/drivers/char/hw_random/core.c
+@@ -68,6 +68,12 @@ static void add_early_randomness(struct
+       unsigned char bytes[16];
+       int bytes_read;
+ 
++      /*
++       * Currently only virtio-rng cannot return data during device
++       * probe, and that's handled in virtio-rng.c itself.  If there
++       * are more such devices, this call to rng_get_data can be
++       * made conditional here instead of doing it per-device.
++       */
+       bytes_read = rng_get_data(rng, bytes, sizeof(bytes), 1);
+       if (bytes_read > 0)
+               add_device_randomness(bytes, bytes_read);
+--- a/drivers/char/hw_random/virtio-rng.c
++++ b/drivers/char/hw_random/virtio-rng.c
+@@ -30,6 +30,8 @@ static unsigned int data_avail;
+ static DECLARE_COMPLETION(have_data);
+ static bool busy;
+ 
++static bool probe_done;
++
+ static void random_recv_done(struct virtqueue *vq)
+ {
+       /* We can get spurious callbacks, e.g. shared IRQs + virtio_pci. */
+@@ -56,6 +58,13 @@ static int virtio_read(struct hwrng *rng
+ {
+       int ret;
+ 
++      /*
++       * Don't ask host for data till we're setup.  This call can
++       * happen during hwrng_register(), after commit d9e7972619.
++       */
++      if (unlikely(!probe_done))
++              return 0;
++
+       if (!busy) {
+               busy = true;
+               init_completion(&have_data);
+@@ -110,6 +119,7 @@ static int probe_common(struct virtio_de
+               return err;
+       }
+ 
++      probe_done = true;
+       return 0;
+ }
+ 

diff --git a/queue-3.15/series b/queue-3.15/series
index 0b3ba094e97506c5aa460584a645226f3cd4ba0b..e3e52179294931c302e9c323371650f7ceebd6a3 100644 (file)
--- a/queue-3.15/series
+++ b/queue-3.15/series
@@ -31,3 +31,4 @@ drm-radeon-fix-irq-ring-buffer-overflow-handling.patch
 drm-radeon-fix-cut-and-paste-issue-for-hawaii.patch
 mm-hugetlb-fix-copy_hugetlb_page_range.patch
 fix-gcc-4.9.0-miscompilation-of-load_balance-in-scheduler.patch
+hwrng-virtio-ensure-reads-happen-after-successful-probe.patch