[PATCH 2/2] net: ethernet: mtk_eth_soc: fix usage of foe_entry_size

[PATCH 2/2] net: ethernet: mtk_eth_soc: fix usage of foe_entry_size

[Daniel Golle]

As sizeof(hwe->data) can now longer be used as the actual size depends
on foe_entry_size, in commit 9d8cb4c096ab02
("net: ethernet: mtk_eth_soc: add foe_entry_size to mtk_eth_soc") the
use of sizeof(hwe->data) is hence replaced.

However, replacing it with ppe->eth->soc->foe_entry_size is wrong as
foe_entry_size represents the size of the whole descriptor and not just
the 'data' field.

Fix this by subtracing the size of the only other field in the struct
'ib1', so we actually end up with the correct size to be copied to the
data field.

Reported-by: Chen Minqiang <ptpt52@gmail.com>
Fixes: 9d8cb4c096ab02 ("net: ethernet: mtk_eth_soc: add foe_entry_size to mtk_eth_soc")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
 drivers/net/ethernet/mediatek/mtk_ppe.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.c b/drivers/net/ethernet/mediatek/mtk_ppe.c
index 4ea2b342f252ac..887f430734f747 100644
--- a/drivers/net/ethernet/mediatek/mtk_ppe.c
+++ b/drivers/net/ethernet/mediatek/mtk_ppe.c
@@ -547,7 +547,7 @@ __mtk_foe_entry_commit(struct mtk_ppe *ppe, struct mtk_foe_entry *entry,
 	}
 
 	hwe = mtk_foe_get_entry(ppe, hash);
-	memcpy(&hwe->data, &entry->data, eth->soc->foe_entry_size);
+	memcpy(&hwe->data, &entry->data, eth->soc->foe_entry_size - sizeof(hwe->ib1));
 	wmb();
 	hwe->ib1 = entry->ib1;
 
-- 
2.37.3

Re: [PATCH 2/2] net: ethernet: mtk_eth_soc: fix usage of foe_entry_size

[Lorenzo Bianconi]

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> As sizeof(hwe->data) can now longer be used as the actual size depends
> on foe_entry_size, in commit 9d8cb4c096ab02
> ("net: ethernet: mtk_eth_soc: add foe_entry_size to mtk_eth_soc") the
> use of sizeof(hwe->data) is hence replaced.
> 
> However, replacing it with ppe->eth->soc->foe_entry_size is wrong as
> foe_entry_size represents the size of the whole descriptor and not just
> the 'data' field.
> 
> Fix this by subtracing the size of the only other field in the struct
> 'ib1', so we actually end up with the correct size to be copied to the
> data field.
> 
> Reported-by: Chen Minqiang <ptpt52@gmail.com>
> Fixes: 9d8cb4c096ab02 ("net: ethernet: mtk_eth_soc: add foe_entry_size to mtk_eth_soc")
> Signed-off-by: Daniel Golle <daniel@makrotopia.org>

Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>

> ---
>  drivers/net/ethernet/mediatek/mtk_ppe.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.c b/drivers/net/ethernet/mediatek/mtk_ppe.c
> index 4ea2b342f252ac..887f430734f747 100644
> --- a/drivers/net/ethernet/mediatek/mtk_ppe.c
> +++ b/drivers/net/ethernet/mediatek/mtk_ppe.c
> @@ -547,7 +547,7 @@ __mtk_foe_entry_commit(struct mtk_ppe *ppe, struct mtk_foe_entry *entry,
>  	}
>  
>  	hwe = mtk_foe_get_entry(ppe, hash);
> -	memcpy(&hwe->data, &entry->data, eth->soc->foe_entry_size);
> +	memcpy(&hwe->data, &entry->data, eth->soc->foe_entry_size - sizeof(hwe->ib1));
>  	wmb();
>  	hwe->ib1 = entry->ib1;
>  
> -- 
> 2.37.3
> 

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