Merge tag 'v3.9-rc5' into patchwork

Linux 3.9-rc5

* tag 'v3.9-rc5': (1080 commits)
  Linux 3.9-rc5
  Revert "lockdep: check that no locks held at freeze time"
  dw_dmac: adjust slave_id accordingly to request line base
  dmaengine: dw_dma: fix endianess for DT xlate function
  PNP: List Rafael Wysocki as a maintainer
  rbd: don't zero-fill non-image object requests
  ia64 idle: delete stale (*idle)() function pointer
  Btrfs: don't drop path when printing out tree errors in scrub
  target: Fix RESERVATION_CONFLICT status regression for iscsi-target special case
  tcm_vhost: Avoid VIRTIO_RING_F_EVENT_IDX feature bit
  Revert "mm: introduce VM_POPULATE flag to better deal with racy userspace programs"
  usb: ftdi_sio: Add support for Mitsubishi FX-USB-AW/-BD
  mg_disk: fix error return code in mg_probe()
  Btrfs: fix wrong return value of btrfs_lookup_csum()
  Btrfs: fix wrong reservation of csums
  Btrfs: fix double free in the btrfs_qgroup_account_ref()
  Btrfs: limit the global reserve to 512mb
  Btrfs: hold the ordered operations mutex when waiting on ordered extents
  Btrfs: fix space accounting for unlink and rename
  Btrfs: fix space leak when we fail to reserve metadata space
  ...

3 files changed, 35 insertions, 9 deletions

diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 1bafb40ec8a2..69ae5972713c 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -40,6 +40,7 @@
 #include <linux/init.h>
 #include <linux/miscdevice.h>
 #include <linux/delay.h>
+#include <linux/slab.h>
 #include <asm/uaccess.h>
 
 
@@ -52,8 +53,12 @@ static struct hwrng *current_rng;
 static LIST_HEAD(rng_list);
 static DEFINE_MUTEX(rng_mutex);
 static int data_avail;
-static u8 rng_buffer[SMP_CACHE_BYTES < 32 ? 32 : SMP_CACHE_BYTES]
-	__cacheline_aligned;
+static u8 *rng_buffer;
+
+static size_t rng_buffer_size(void)
+{
+	return SMP_CACHE_BYTES < 32 ? 32 : SMP_CACHE_BYTES;
+}
 
 static inline int hwrng_init(struct hwrng *rng)
 {
@@ -116,7 +121,7 @@ static ssize_t rng_dev_read(struct file *filp, char __user *buf,
 
 		if (!data_avail) {
 			bytes_read = rng_get_data(current_rng, rng_buffer,
-				sizeof(rng_buffer),
+				rng_buffer_size(),
 				!(filp->f_flags & O_NONBLOCK));
 			if (bytes_read < 0) {
 				err = bytes_read;
@@ -307,6 +312,14 @@ int hwrng_register(struct hwrng *rng)
 
 	mutex_lock(&rng_mutex);
 
+	/* kmalloc makes this safe for virt_to_page() in virtio_rng.c */
+	err = -ENOMEM;
+	if (!rng_buffer) {
+		rng_buffer = kmalloc(rng_buffer_size(), GFP_KERNEL);
+		if (!rng_buffer)
+			goto out_unlock;
+	}
+
 	/* Must not register two RNGs with the same name. */
 	err = -EEXIST;
 	list_for_each_entry(tmp, &rng_list, list) {
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index 10fd71ccf587..6bf4d47324eb 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -92,14 +92,22 @@ static int probe_common(struct virtio_device *vdev)
 {
 	int err;
 
+	if (vq) {
+		/* We only support one device for now */
+		return -EBUSY;
+	}
 	/* We expect a single virtqueue. */
 	vq = virtio_find_single_vq(vdev, random_recv_done, "input");
-	if (IS_ERR(vq))
-		return PTR_ERR(vq);
+	if (IS_ERR(vq)) {
+		err = PTR_ERR(vq);
+		vq = NULL;
+		return err;
+	}
 
 	err = hwrng_register(&virtio_hwrng);
 	if (err) {
 		vdev->config->del_vqs(vdev);
+		vq = NULL;
 		return err;
 	}
 
@@ -112,6 +120,7 @@ static void remove_common(struct virtio_device *vdev)
 	busy = false;
 	hwrng_unregister(&virtio_hwrng);
 	vdev->config->del_vqs(vdev);
+	vq = NULL;
 }
 
 static int virtrng_probe(struct virtio_device *vdev)
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 594bda9dcfc8..32a6c5764950 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -852,6 +852,7 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
 		      int reserved)
 {
 	unsigned long flags;
+	int wakeup_write = 0;
 
 	/* Hold lock while accounting */
 	spin_lock_irqsave(&r->lock, flags);
@@ -873,10 +874,8 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
 		else
 			r->entropy_count = reserved;
 
-		if (r->entropy_count < random_write_wakeup_thresh) {
-			wake_up_interruptible(&random_write_wait);
-			kill_fasync(&fasync, SIGIO, POLL_OUT);
-		}
+		if (r->entropy_count < random_write_wakeup_thresh)
+			wakeup_write = 1;
 	}
 
 	DEBUG_ENT("debiting %zu entropy credits from %s%s\n",
@@ -884,6 +883,11 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
 
 	spin_unlock_irqrestore(&r->lock, flags);
 
+	if (wakeup_write) {
+		wake_up_interruptible(&random_write_wait);
+		kill_fasync(&fasync, SIGIO, POLL_OUT);
+	}
+
 	return nbytes;
 }