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authorK. Y. Srinivasan <kys@microsoft.com>2016-04-02 17:59:47 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-04-30 14:00:19 -0700
commitd45faaeedb762a3965a0246cf831e55045dd6ef8 (patch)
treed33ec75e96196b925c1ba72933f5e73016c73ddb /drivers/hv
parenta6341f000024cdf1ec14dc26743a409a17378db5 (diff)
downloadop-kernel-dev-d45faaeedb762a3965a0246cf831e55045dd6ef8.zip
op-kernel-dev-d45faaeedb762a3965a0246cf831e55045dd6ef8.tar.gz
Drivers: hv: vmbus: Use READ_ONCE() to read variables that are volatile
Use the READ_ONCE macro to access variabes that can change asynchronously. This is the recommended mechanism for dealing with "unsafe" compiler optimizations. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv')
-rw-r--r--drivers/hv/ring_buffer.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 544362c..6ea1b55 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -69,7 +69,7 @@ u32 hv_end_read(struct hv_ring_buffer_info *rbi)
static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi)
{
mb();
- if (rbi->ring_buffer->interrupt_mask)
+ if (READ_ONCE(rbi->ring_buffer->interrupt_mask))
return false;
/* check interrupt_mask before read_index */
@@ -78,7 +78,7 @@ static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi)
* This is the only case we need to signal when the
* ring transitions from being empty to non-empty.
*/
- if (old_write == rbi->ring_buffer->read_index)
+ if (old_write == READ_ONCE(rbi->ring_buffer->read_index))
return true;
return false;
@@ -117,7 +117,7 @@ static bool hv_need_to_signal_on_read(struct hv_ring_buffer_info *rbi)
*/
mb();
- pending_sz = rbi->ring_buffer->pending_send_sz;
+ pending_sz = READ_ONCE(rbi->ring_buffer->pending_send_sz);
/* If the other end is not blocked on write don't bother. */
if (pending_sz == 0)
return false;
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