Merge tag 'char-misc-5.2-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc update part 1 from Greg KH:
 "This contains only a small number of bugfixes that would have gone to
  you for 5.1-rc8 if that had happened, but instead I let them sit in
  linux-next for an extra week just "to be sure".

  The "big" patch here is for hyper-v, fixing a bug in their sysfs files
  that could cause big problems. The others are all small fixes,
  resolving reported issues that showed up in 5.1-rcs, plus some odd
  'static' cleanups for the phy drivers that really should have waited
  for -rc1. Most of these are tagged for the stable trees, so 5.1 will
  pick them up.

  All of these have been in linux-next for a while, with no reported
  issues"

* tag 'char-misc-5.2-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  misc: rtsx: Fixed rts5260 power saving parameter and sd glitch
  binder: take read mode of mmap_sem in binder_alloc_free_page()
  intel_th: pci: Add Comet Lake support
  stm class: Fix channel bitmap on 32-bit systems
  stm class: Fix channel free in stm output free path
  phy: sun4i-usb: Make sure to disable PHY0 passby for peripheral mode
  phy: fix platform_no_drv_owner.cocci warnings
  phy: mapphone-mdm6600: add gpiolib dependency
  phy: ti: usb2: fix OMAP_CONTROL_PHY dependency
  phy: allwinner: allow compile testing
  phy: qcom-ufs: Make ufs_qcom_phy_disable_iface_clk static
  phy: rockchip-typec: Make usb3_pll_cfg and dp_pll_cfg static
  phy: phy-twl4030-usb: Fix cable state handling
  Drivers: hv: vmbus: Remove the undesired put_cpu_ptr() in hv_synic_cleanup()
  Drivers: hv: vmbus: Fix race condition with new ring_buffer_info mutex
  Drivers: hv: vmbus: Set ring_info field to 0 and remove memset
  Drivers: hv: vmbus: Refactor chan->state if statement
  Drivers: hv: vmbus: Expose monitor data only when monitor pages are used

1 files changed, 18 insertions, 4 deletions

diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 9e8b31ccc142..121a01c43298 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -166,14 +166,18 @@ hv_get_ringbuffer_availbytes(const struct hv_ring_buffer_info *rbi,
 }
 
 /* Get various debug metrics for the specified ring buffer. */
-int hv_ringbuffer_get_debuginfo(const struct hv_ring_buffer_info *ring_info,
+int hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info,
 				struct hv_ring_buffer_debug_info *debug_info)
 {
 	u32 bytes_avail_towrite;
 	u32 bytes_avail_toread;
 
-	if (!ring_info->ring_buffer)
+	mutex_lock(&ring_info->ring_buffer_mutex);
+
+	if (!ring_info->ring_buffer) {
+		mutex_unlock(&ring_info->ring_buffer_mutex);
 		return -EINVAL;
+	}
 
 	hv_get_ringbuffer_availbytes(ring_info,
 				     &bytes_avail_toread,
@@ -184,10 +188,19 @@ int hv_ringbuffer_get_debuginfo(const struct hv_ring_buffer_info *ring_info,
 	debug_info->current_write_index = ring_info->ring_buffer->write_index;
 	debug_info->current_interrupt_mask
 		= ring_info->ring_buffer->interrupt_mask;
+	mutex_unlock(&ring_info->ring_buffer_mutex);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(hv_ringbuffer_get_debuginfo);
 
+/* Initialize a channel's ring buffer info mutex locks */
+void hv_ringbuffer_pre_init(struct vmbus_channel *channel)
+{
+	mutex_init(&channel->inbound.ring_buffer_mutex);
+	mutex_init(&channel->outbound.ring_buffer_mutex);
+}
+
 /* Initialize the ring buffer. */
 int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
 		       struct page *pages, u32 page_cnt)
@@ -197,8 +210,6 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
 
 	BUILD_BUG_ON((sizeof(struct hv_ring_buffer) != PAGE_SIZE));
 
-	memset(ring_info, 0, sizeof(struct hv_ring_buffer_info));
-
 	/*
 	 * First page holds struct hv_ring_buffer, do wraparound mapping for
 	 * the rest.
@@ -232,6 +243,7 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
 		reciprocal_value(ring_info->ring_size / 10);
 	ring_info->ring_datasize = ring_info->ring_size -
 		sizeof(struct hv_ring_buffer);
+	ring_info->priv_read_index = 0;
 
 	spin_lock_init(&ring_info->ring_lock);
 
@@ -241,8 +253,10 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
 /* Cleanup the ring buffer. */
 void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info)
 {
+	mutex_lock(&ring_info->ring_buffer_mutex);
 	vunmap(ring_info->ring_buffer);
 	ring_info->ring_buffer = NULL;
+	mutex_unlock(&ring_info->ring_buffer_mutex);
 }
 
 /* Write to the ring buffer. */