6.15-stable review patch. If anyone has any objections, please let me know.
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From: Johan Hovold johan+linaro@kernel.org
commit ab52e3e44fe9b666281752e2481d11e25b0e3fdd upstream.
Add the missing memory barrier to make sure that the REO dest ring descriptor is read after the head pointer to avoid using stale data on weakly ordered architectures like aarch64.
This may fix the ring-buffer corruption worked around by commit f9fff67d2d7c ("wifi: ath11k: Fix SKB corruption in REO destination ring") by silently discarding data, and may possibly also address user reported errors like:
ath11k_pci 0006:01:00.0: msdu_done bit in attention is not set
Tested-on: WCN6855 hw2.1 WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.41
Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices") Cc: stable@vger.kernel.org # 5.6 Link: https://bugzilla.kernel.org/show_bug.cgi?id=218005 Signed-off-by: Johan Hovold johan+linaro@kernel.org Tested-by: Clayton Craft clayton@craftyguy.net Link: https://patch.msgid.link/20250321145302.4775-1-johan+linaro@kernel.org Signed-off-by: Jeff Johnson jeff.johnson@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/wireless/ath/ath11k/dp_rx.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-)
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c +++ b/drivers/net/wireless/ath/ath11k/dp_rx.c @@ -2637,7 +2637,7 @@ int ath11k_dp_process_rx(struct ath11k_b struct ath11k *ar; struct hal_reo_dest_ring *desc; enum hal_reo_dest_ring_push_reason push_reason; - u32 cookie; + u32 cookie, info0, rx_msdu_info0, rx_mpdu_info0; int i;
for (i = 0; i < MAX_RADIOS; i++) @@ -2650,11 +2650,14 @@ int ath11k_dp_process_rx(struct ath11k_b try_again: ath11k_hal_srng_access_begin(ab, srng);
+ /* Make sure descriptor is read after the head pointer. */ + dma_rmb(); + while (likely(desc = (struct hal_reo_dest_ring *)ath11k_hal_srng_dst_get_next_entry(ab, srng))) { cookie = FIELD_GET(BUFFER_ADDR_INFO1_SW_COOKIE, - desc->buf_addr_info.info1); + READ_ONCE(desc->buf_addr_info.info1)); buf_id = FIELD_GET(DP_RXDMA_BUF_COOKIE_BUF_ID, cookie); mac_id = FIELD_GET(DP_RXDMA_BUF_COOKIE_PDEV_ID, cookie); @@ -2683,8 +2686,9 @@ try_again:
num_buffs_reaped[mac_id]++;
+ info0 = READ_ONCE(desc->info0); push_reason = FIELD_GET(HAL_REO_DEST_RING_INFO0_PUSH_REASON, - desc->info0); + info0); if (unlikely(push_reason != HAL_REO_DEST_RING_PUSH_REASON_ROUTING_INSTRUCTION)) { dev_kfree_skb_any(msdu); @@ -2692,18 +2696,21 @@ try_again: continue; }
- rxcb->is_first_msdu = !!(desc->rx_msdu_info.info0 & + rx_msdu_info0 = READ_ONCE(desc->rx_msdu_info.info0); + rx_mpdu_info0 = READ_ONCE(desc->rx_mpdu_info.info0); + + rxcb->is_first_msdu = !!(rx_msdu_info0 & RX_MSDU_DESC_INFO0_FIRST_MSDU_IN_MPDU); - rxcb->is_last_msdu = !!(desc->rx_msdu_info.info0 & + rxcb->is_last_msdu = !!(rx_msdu_info0 & RX_MSDU_DESC_INFO0_LAST_MSDU_IN_MPDU); - rxcb->is_continuation = !!(desc->rx_msdu_info.info0 & + rxcb->is_continuation = !!(rx_msdu_info0 & RX_MSDU_DESC_INFO0_MSDU_CONTINUATION); rxcb->peer_id = FIELD_GET(RX_MPDU_DESC_META_DATA_PEER_ID, - desc->rx_mpdu_info.meta_data); + READ_ONCE(desc->rx_mpdu_info.meta_data)); rxcb->seq_no = FIELD_GET(RX_MPDU_DESC_INFO0_SEQ_NUM, - desc->rx_mpdu_info.info0); + rx_mpdu_info0); rxcb->tid = FIELD_GET(HAL_REO_DEST_RING_INFO0_RX_QUEUE_NUM, - desc->info0); + info0);
rxcb->mac_id = mac_id; __skb_queue_tail(&msdu_list[mac_id], msdu);