Re: [PATCH net-next 1/2] net: atlantic: free stranded TX buffers on ring deinit

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] The patch fixes a resource leak of stranded TX buffers on interface teardown by replacing `aq_ring_tx_clean()` with the restored `aq_ring_tx_deinit()` in `aq_vec_deinit()`, but misses the identical leak pattern in `aq_ptp_ring_deinit()`.
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--- Patch [1]: [PATCH net-next 1/2] net: atlantic: free stranded TX buffers on ring deinit ---
commit 0bceee292a00058408f6f3baf2ae8103a4e90f9c
Author: Yangyu Chen <cyy@cyyself.name>

net: atlantic: free stranded TX buffers on ring deinit

This commit brings back aq_ring_tx_deinit() to properly drain TX rings
during teardown. This prevents silent memory leaks of stranded buffers and
stalls during page pool destruction when the interface goes down under
TX or XDP_TX load.

> diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_vec.c b/drivers/net/ethernet/aquantia/atlantic/aq_vec.c
> index 2f9033ceed8ce..05814fea0f5f7 100644
> --- a/drivers/net/ethernet/aquantia/atlantic/aq_vec.c
> +++ b/drivers/net/ethernet/aquantia/atlantic/aq_vec.c
[ ... ]
> @@ -275,7 +275,7 @@ void aq_vec_deinit(struct aq_vec_s *self)
>  
>  	for (i = 0U; self->tx_rings > i; ++i) {
>  		ring = self->ring[i];
> -		aq_ring_tx_clean(&ring[AQ_VEC_TX_ID]);
> +		aq_ring_tx_deinit(&ring[AQ_VEC_TX_ID]);

[Severity: High]
This is a pre-existing issue, but should aq_ptp_ring_deinit() also be
updated to use aq_ring_tx_deinit() instead of aq_ring_tx_clean()?

In drivers/net/ethernet/aquantia/atlantic/aq_ptp.c:aq_ptp_ring_deinit():

	aq_ring_tx_clean(&aq_ptp->ptp_tx);
	aq_ring_rx_deinit(&aq_ptp->ptp_rx);

Since aq_ring_tx_clean() stops at hw_head and applies a budget, any
in-flight SKBs and their DMA mappings on the PTP TX ring might still be
permanently leaked when the hardware is stopped and the interface is
brought down.

Does the PTP ring teardown need the same fix applied here?

>  		aq_ring_rx_deinit(&ring[AQ_VEC_RX_ID]);
>  	}
>

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Sashiko AI review · https://sashiko.dev/#/patchset/tencent_7DB01BE7F8FA056BB5F11D3570CF636C4309@qq.com?part=1