2023-12-08 07:50:17

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH wireless] wifi: mt76: fix crash with WED rx support enabled

If WED rx is enabled, rx buffers are added to a buffer pool that can be
filled from multiple page pools. Because buffers freed from rx poll are
not guaranteed to belong to the processed queue's page pool, lockless
caching must not be used in this case.

Cc: [email protected]
Fixes: 2f5c3c77fc9b ("wifi: mt76: switch to page_pool allocator")
Signed-off-by: Felix Fietkau <[email protected]>
---
drivers/net/wireless/mediatek/mt76/dma.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
index 511fe7e6e744..68ad915203aa 100644
--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -783,7 +783,7 @@ mt76_dma_rx_reset(struct mt76_dev *dev, enum mt76_rxq_id qid)

static void
mt76_add_fragment(struct mt76_dev *dev, struct mt76_queue *q, void *data,
- int len, bool more, u32 info)
+ int len, bool more, u32 info, bool allow_direct)
{
struct sk_buff *skb = q->rx_head;
struct skb_shared_info *shinfo = skb_shinfo(skb);
@@ -795,7 +795,7 @@ mt76_add_fragment(struct mt76_dev *dev, struct mt76_queue *q, void *data,

skb_add_rx_frag(skb, nr_frags, page, offset, len, q->buf_size);
} else {
- mt76_put_page_pool_buf(data, true);
+ mt76_put_page_pool_buf(data, allow_direct);
}

if (more)
@@ -815,6 +815,7 @@ mt76_dma_rx_process(struct mt76_dev *dev, struct mt76_queue *q, int budget)
struct sk_buff *skb;
unsigned char *data;
bool check_ddone = false;
+ bool allow_direct = !mt76_queue_is_wed_rx(q);
bool more;

if (IS_ENABLED(CONFIG_NET_MEDIATEK_SOC_WED) &&
@@ -855,7 +856,8 @@ mt76_dma_rx_process(struct mt76_dev *dev, struct mt76_queue *q, int budget)
}

if (q->rx_head) {
- mt76_add_fragment(dev, q, data, len, more, info);
+ mt76_add_fragment(dev, q, data, len, more, info,
+ allow_direct);
continue;
}

@@ -884,7 +886,7 @@ mt76_dma_rx_process(struct mt76_dev *dev, struct mt76_queue *q, int budget)
continue;

free_frag:
- mt76_put_page_pool_buf(data, true);
+ mt76_put_page_pool_buf(data, allow_direct);
}

mt76_dma_rx_fill(dev, q, true);
--
2.41.0



2023-12-08 09:50:53

by Lorenzo Bianconi

[permalink] [raw]
Subject: Re: [PATCH wireless] wifi: mt76: fix crash with WED rx support enabled

> If WED rx is enabled, rx buffers are added to a buffer pool that can be
> filled from multiple page pools. Because buffers freed from rx poll are
> not guaranteed to belong to the processed queue's page pool, lockless
> caching must not be used in this case.

Acked-by: Lorenzo Bianconi <[email protected]>

>
> Cc: [email protected]
> Fixes: 2f5c3c77fc9b ("wifi: mt76: switch to page_pool allocator")
> Signed-off-by: Felix Fietkau <[email protected]>
> ---
> drivers/net/wireless/mediatek/mt76/dma.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
> index 511fe7e6e744..68ad915203aa 100644
> --- a/drivers/net/wireless/mediatek/mt76/dma.c
> +++ b/drivers/net/wireless/mediatek/mt76/dma.c
> @@ -783,7 +783,7 @@ mt76_dma_rx_reset(struct mt76_dev *dev, enum mt76_rxq_id qid)
>
> static void
> mt76_add_fragment(struct mt76_dev *dev, struct mt76_queue *q, void *data,
> - int len, bool more, u32 info)
> + int len, bool more, u32 info, bool allow_direct)
> {
> struct sk_buff *skb = q->rx_head;
> struct skb_shared_info *shinfo = skb_shinfo(skb);
> @@ -795,7 +795,7 @@ mt76_add_fragment(struct mt76_dev *dev, struct mt76_queue *q, void *data,
>
> skb_add_rx_frag(skb, nr_frags, page, offset, len, q->buf_size);
> } else {
> - mt76_put_page_pool_buf(data, true);
> + mt76_put_page_pool_buf(data, allow_direct);
> }
>
> if (more)
> @@ -815,6 +815,7 @@ mt76_dma_rx_process(struct mt76_dev *dev, struct mt76_queue *q, int budget)
> struct sk_buff *skb;
> unsigned char *data;
> bool check_ddone = false;
> + bool allow_direct = !mt76_queue_is_wed_rx(q);
> bool more;
>
> if (IS_ENABLED(CONFIG_NET_MEDIATEK_SOC_WED) &&
> @@ -855,7 +856,8 @@ mt76_dma_rx_process(struct mt76_dev *dev, struct mt76_queue *q, int budget)
> }
>
> if (q->rx_head) {
> - mt76_add_fragment(dev, q, data, len, more, info);
> + mt76_add_fragment(dev, q, data, len, more, info,
> + allow_direct);
> continue;
> }
>
> @@ -884,7 +886,7 @@ mt76_dma_rx_process(struct mt76_dev *dev, struct mt76_queue *q, int budget)
> continue;
>
> free_frag:
> - mt76_put_page_pool_buf(data, true);
> + mt76_put_page_pool_buf(data, allow_direct);
> }
>
> mt76_dma_rx_fill(dev, q, true);
> --
> 2.41.0
>
>


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2023-12-11 13:13:51

by Kalle Valo

[permalink] [raw]
Subject: Re: [PATCH wireless] wifi: mt76: fix crash with WED rx support enabled

Felix Fietkau <[email protected]> writes:

> If WED rx is enabled, rx buffers are added to a buffer pool that can be
> filled from multiple page pools. Because buffers freed from rx poll are
> not guaranteed to belong to the processed queue's page pool, lockless
> caching must not be used in this case.
>
> Cc: [email protected]
> Fixes: 2f5c3c77fc9b ("wifi: mt76: switch to page_pool allocator")
> Signed-off-by: Felix Fietkau <[email protected]>

I assigned this to me on patchwork and will apply to wireless later.

--
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

2023-12-12 14:26:19

by Kalle Valo

[permalink] [raw]
Subject: Re: [PATCH wireless] wifi: mt76: fix crash with WED rx support enabled

Felix Fietkau <[email protected]> wrote:

> If WED rx is enabled, rx buffers are added to a buffer pool that can be
> filled from multiple page pools. Because buffers freed from rx poll are
> not guaranteed to belong to the processed queue's page pool, lockless
> caching must not be used in this case.
>
> Cc: [email protected]
> Fixes: 2f5c3c77fc9b ("wifi: mt76: switch to page_pool allocator")
> Signed-off-by: Felix Fietkau <[email protected]>
> Acked-by: Lorenzo Bianconi <[email protected]>

Patch applied to wireless.git, thanks.

cd607f2cbbbe wifi: mt76: fix crash with WED rx support enabled

--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches