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authorPhilippe Schenker <philippe.schenker@toradex.com>2022-05-19 14:57:48 +0200
committerPhilippe Schenker <philippe.schenker@toradex.com>2022-05-19 14:57:48 +0200
commit0e61b511dd8474280ba674590daa55f30433b7d4 (patch)
tree48c35f63dc1101d0d528b5d79c81849b99ca7c6d /drivers/hv/ring_buffer.c
parentc4bda7fe18b3ff6898f8fa110a3d60ee8f4379a0 (diff)
parent01565c91b789a1612051e735a65f11096a6f08e8 (diff)
Merge tag 'v5.4.193' into update-to-2.3.7__5.4-2.3.x-imx
This is the 5.4.193 stable release Conflicts: arch/arm64/boot/dts/freescale/fsl-ls1028a-qds.dts drivers/edac/synopsys_edac.c drivers/mmc/host/sdhci-esdhc-imx.c drivers/mmc/host/sdhci.c drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c sound/soc/codecs/msm8916-wcd-analog.c
Diffstat (limited to 'drivers/hv/ring_buffer.c')
-rw-r--r--drivers/hv/ring_buffer.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 9a03b163cbbd..59f1e64908b1 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -378,7 +378,16 @@ int hv_ringbuffer_read(struct vmbus_channel *channel,
static u32 hv_pkt_iter_avail(const struct hv_ring_buffer_info *rbi)
{
u32 priv_read_loc = rbi->priv_read_index;
- u32 write_loc = READ_ONCE(rbi->ring_buffer->write_index);
+ u32 write_loc;
+
+ /*
+ * The Hyper-V host writes the packet data, then uses
+ * store_release() to update the write_index. Use load_acquire()
+ * here to prevent loads of the packet data from being re-ordered
+ * before the read of the write_index and potentially getting
+ * stale data.
+ */
+ write_loc = virt_load_acquire(&rbi->ring_buffer->write_index);
if (write_loc >= priv_read_loc)
return write_loc - priv_read_loc;