* [PATCH][next] net: systemport: fix double shift of a vlan_tci by VLAN_PRIO_SHIFT
@ 2020-07-08 18:37 ` Colin King
0 siblings, 0 replies; 6+ messages in thread
From: Colin King @ 2020-07-08 18:37 UTC (permalink / raw)
To: Florian Fainelli, David S . Miller, Jakub Kicinski,
bcm-kernel-feedback-list, netdev
Cc: kernel-janitors, linux-kernel
From: Colin Ian King <colin.king@canonical.com>
Currently the u16 skb->vlan_tci is being right shifted twice by
VLAN_PRIO_SHIFT, once in the macro skb_vlan_tag_get_pri and explicitly
by VLAN_PRIO_SHIFT afterwards. The combined shift amount is larger than
the u16 so the end result is always zero. Remove the second explicit
shift as this is extraneous.
Fixes: 6e9fdb60d362 ("net: systemport: Add support for VLAN transmit acceleration")
Addresses-Coverity: ("Operands don't affect result")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
drivers/net/ethernet/broadcom/bcmsysport.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c
index b470551bae4f..dfed9ade6950 100644
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -1250,8 +1250,7 @@ static struct sk_buff *bcm_sysport_insert_tsb(struct sk_buff *skb,
memset(tsb, 0, sizeof(*tsb));
if (skb_vlan_tag_present(skb)) {
- tsb->pcp_dei_vid = (skb_vlan_tag_get_prio(skb) >>
- VLAN_PRIO_SHIFT & PCP_DEI_MASK);
+ tsb->pcp_dei_vid = skb_vlan_tag_get_prio(skb) & PCP_DEI_MASK;
tsb->pcp_dei_vid |= (u32)skb_vlan_tag_get_id(skb) << VID_SHIFT;
}
--
2.27.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH][next] net: systemport: fix double shift of a vlan_tci by VLAN_PRIO_SHIFT
@ 2020-07-08 18:37 ` Colin King
0 siblings, 0 replies; 6+ messages in thread
From: Colin King @ 2020-07-08 18:37 UTC (permalink / raw)
To: Florian Fainelli, David S . Miller, Jakub Kicinski,
bcm-kernel-feedback-list, netdev
Cc: kernel-janitors, linux-kernel
From: Colin Ian King <colin.king@canonical.com>
Currently the u16 skb->vlan_tci is being right shifted twice by
VLAN_PRIO_SHIFT, once in the macro skb_vlan_tag_get_pri and explicitly
by VLAN_PRIO_SHIFT afterwards. The combined shift amount is larger than
the u16 so the end result is always zero. Remove the second explicit
shift as this is extraneous.
Fixes: 6e9fdb60d362 ("net: systemport: Add support for VLAN transmit acceleration")
Addresses-Coverity: ("Operands don't affect result")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
drivers/net/ethernet/broadcom/bcmsysport.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c
index b470551bae4f..dfed9ade6950 100644
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -1250,8 +1250,7 @@ static struct sk_buff *bcm_sysport_insert_tsb(struct sk_buff *skb,
memset(tsb, 0, sizeof(*tsb));
if (skb_vlan_tag_present(skb)) {
- tsb->pcp_dei_vid = (skb_vlan_tag_get_prio(skb) >>
- VLAN_PRIO_SHIFT & PCP_DEI_MASK);
+ tsb->pcp_dei_vid = skb_vlan_tag_get_prio(skb) & PCP_DEI_MASK;
tsb->pcp_dei_vid |= (u32)skb_vlan_tag_get_id(skb) << VID_SHIFT;
}
--
2.27.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH][next] net: systemport: fix double shift of a vlan_tci by VLAN_PRIO_SHIFT
2020-07-08 18:37 ` Colin King
@ 2020-07-08 20:32 ` Florian Fainelli
-1 siblings, 0 replies; 6+ messages in thread
From: Florian Fainelli @ 2020-07-08 20:32 UTC (permalink / raw)
To: Colin King, David S . Miller, Jakub Kicinski,
bcm-kernel-feedback-list, netdev
Cc: kernel-janitors, linux-kernel
On 7/8/2020 11:37 AM, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> Currently the u16 skb->vlan_tci is being right shifted twice by
> VLAN_PRIO_SHIFT, once in the macro skb_vlan_tag_get_pri and explicitly
> by VLAN_PRIO_SHIFT afterwards. The combined shift amount is larger than
> the u16 so the end result is always zero. Remove the second explicit
> shift as this is extraneous.
>
> Fixes: 6e9fdb60d362 ("net: systemport: Add support for VLAN transmit acceleration")
> Addresses-Coverity: ("Operands don't affect result")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
The change was forward ported from a 4.9 kernel where the shift is not
done, I should have checked the helper usage, thanks!
--
Florian
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][next] net: systemport: fix double shift of a vlan_tci by VLAN_PRIO_SHIFT
@ 2020-07-08 20:32 ` Florian Fainelli
0 siblings, 0 replies; 6+ messages in thread
From: Florian Fainelli @ 2020-07-08 20:32 UTC (permalink / raw)
To: Colin King, David S . Miller, Jakub Kicinski,
bcm-kernel-feedback-list, netdev
Cc: kernel-janitors, linux-kernel
On 7/8/2020 11:37 AM, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> Currently the u16 skb->vlan_tci is being right shifted twice by
> VLAN_PRIO_SHIFT, once in the macro skb_vlan_tag_get_pri and explicitly
> by VLAN_PRIO_SHIFT afterwards. The combined shift amount is larger than
> the u16 so the end result is always zero. Remove the second explicit
> shift as this is extraneous.
>
> Fixes: 6e9fdb60d362 ("net: systemport: Add support for VLAN transmit acceleration")
> Addresses-Coverity: ("Operands don't affect result")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
The change was forward ported from a 4.9 kernel where the shift is not
done, I should have checked the helper usage, thanks!
--
Florian
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][next] net: systemport: fix double shift of a vlan_tci by VLAN_PRIO_SHIFT
2020-07-08 18:37 ` Colin King
@ 2020-07-09 20:07 ` David Miller
-1 siblings, 0 replies; 6+ messages in thread
From: David Miller @ 2020-07-09 20:07 UTC (permalink / raw)
To: colin.king
Cc: f.fainelli, kuba, bcm-kernel-feedback-list, netdev,
kernel-janitors, linux-kernel
From: Colin King <colin.king@canonical.com>
Date: Wed, 8 Jul 2020 19:37:23 +0100
> From: Colin Ian King <colin.king@canonical.com>
>
> Currently the u16 skb->vlan_tci is being right shifted twice by
> VLAN_PRIO_SHIFT, once in the macro skb_vlan_tag_get_pri and explicitly
> by VLAN_PRIO_SHIFT afterwards. The combined shift amount is larger than
> the u16 so the end result is always zero. Remove the second explicit
> shift as this is extraneous.
>
> Fixes: 6e9fdb60d362 ("net: systemport: Add support for VLAN transmit acceleration")
> Addresses-Coverity: ("Operands don't affect result")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
Applied to net-next, thanks.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][next] net: systemport: fix double shift of a vlan_tci by VLAN_PRIO_SHIFT
@ 2020-07-09 20:07 ` David Miller
0 siblings, 0 replies; 6+ messages in thread
From: David Miller @ 2020-07-09 20:07 UTC (permalink / raw)
To: colin.king
Cc: f.fainelli, kuba, bcm-kernel-feedback-list, netdev,
kernel-janitors, linux-kernel
From: Colin King <colin.king@canonical.com>
Date: Wed, 8 Jul 2020 19:37:23 +0100
> From: Colin Ian King <colin.king@canonical.com>
>
> Currently the u16 skb->vlan_tci is being right shifted twice by
> VLAN_PRIO_SHIFT, once in the macro skb_vlan_tag_get_pri and explicitly
> by VLAN_PRIO_SHIFT afterwards. The combined shift amount is larger than
> the u16 so the end result is always zero. Remove the second explicit
> shift as this is extraneous.
>
> Fixes: 6e9fdb60d362 ("net: systemport: Add support for VLAN transmit acceleration")
> Addresses-Coverity: ("Operands don't affect result")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
Applied to net-next, thanks.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-07-09 20:07 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2020-07-08 18:37 [PATCH][next] net: systemport: fix double shift of a vlan_tci by VLAN_PRIO_SHIFT Colin King
2020-07-08 18:37 ` Colin King
2020-07-08 20:32 ` Florian Fainelli
2020-07-08 20:32 ` Florian Fainelli
2020-07-09 20:07 ` David Miller
2020-07-09 20:07 ` David Miller
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