diff mbox series

[net] net: stmmac: Correct byte order of perfect_match

Message ID 20240723-stmmac-perfect-match-v1-1-678a800343b2@kernel.org (mailing list archive)
State New, archived
Headers show
Series [net] net: stmmac: Correct byte order of perfect_match | expand

Commit Message

Simon Horman July 23, 2024, 1:29 p.m. UTC
The perfect_match parameter of the update_vlan_hash operation is __le16,
and is correctly converted from host byte-order in the lone caller,
stmmac_vlan_update().

However, the implementations of this caller, dwxgmac2_update_vlan_hash()
and dwxgmac2_update_vlan_hash(), both treat this parameter as host byte
order, using the following pattern:

	u32 value = ...
	...
	writel(value | perfect_match, ...);

This is not correct because both:
1) value is host byte order; and
2) writel expects a host byte order value as it's first argument

I believe that this will break on big endian systems. And I expect it
has gone unnoticed by only being exercised on little endian systems.

The approach taken by this patch is to update the callback, and it's
caller to simply use a host byte order value.

Flagged by Sparse.
Compile tested only.

Fixes: c7ab0b8088d7 ("net: stmmac: Fallback to VLAN Perfect filtering if HASH is not available")
Signed-off-by: Simon Horman <horms@kernel.org>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c   | 2 +-
 drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c | 2 +-
 drivers/net/ethernet/stmicro/stmmac/hwif.h          | 2 +-
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c   | 4 ++--
 4 files changed, 5 insertions(+), 5 deletions(-)

Comments

Maxime Chevallier July 23, 2024, 3:50 p.m. UTC | #1
Hello Simon,

On Tue, 23 Jul 2024 14:29:27 +0100
Simon Horman <horms@kernel.org> wrote:

> The perfect_match parameter of the update_vlan_hash operation is __le16,
> and is correctly converted from host byte-order in the lone caller,
> stmmac_vlan_update().
> 
> However, the implementations of this caller, dwxgmac2_update_vlan_hash()
> and dwxgmac2_update_vlan_hash(), both treat this parameter as host byte
> order, using the following pattern:
> 
> 	u32 value = ...
> 	...
> 	writel(value | perfect_match, ...);
> 
> This is not correct because both:
> 1) value is host byte order; and
> 2) writel expects a host byte order value as it's first argument
> 
> I believe that this will break on big endian systems. And I expect it
> has gone unnoticed by only being exercised on little endian systems.
> 
> The approach taken by this patch is to update the callback, and it's
> caller to simply use a host byte order value.
> 
> Flagged by Sparse.
> Compile tested only.
> 
> Fixes: c7ab0b8088d7 ("net: stmmac: Fallback to VLAN Perfect filtering if HASH is not available")
> Signed-off-by: Simon Horman <horms@kernel.org>

Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>

Thanks,

Maxime
patchwork-bot+netdevbpf@kernel.org July 24, 2024, 2:20 p.m. UTC | #2
Hello:

This patch was applied to netdev/net.git (main)
by David S. Miller <davem@davemloft.net>:

On Tue, 23 Jul 2024 14:29:27 +0100 you wrote:
> The perfect_match parameter of the update_vlan_hash operation is __le16,
> and is correctly converted from host byte-order in the lone caller,
> stmmac_vlan_update().
> 
> However, the implementations of this caller, dwxgmac2_update_vlan_hash()
> and dwxgmac2_update_vlan_hash(), both treat this parameter as host byte
> order, using the following pattern:
> 
> [...]

Here is the summary with links:
  - [net] net: stmmac: Correct byte order of perfect_match
    https://git.kernel.org/netdev/net/c/e9dbebae2e3c

You are awesome, thank you!
diff mbox series

Patch

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
index dbd9f93b2460..f98741d2607e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -977,7 +977,7 @@  static void dwmac4_set_mac_loopback(void __iomem *ioaddr, bool enable)
 }
 
 static void dwmac4_update_vlan_hash(struct mac_device_info *hw, u32 hash,
-				    __le16 perfect_match, bool is_double)
+				    u16 perfect_match, bool is_double)
 {
 	void __iomem *ioaddr = hw->pcsr;
 	u32 value;
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
index 6a987cf598e4..f196cd99d510 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
@@ -615,7 +615,7 @@  static int dwxgmac2_rss_configure(struct mac_device_info *hw,
 }
 
 static void dwxgmac2_update_vlan_hash(struct mac_device_info *hw, u32 hash,
-				      __le16 perfect_match, bool is_double)
+				      u16 perfect_match, bool is_double)
 {
 	void __iomem *ioaddr = hw->pcsr;
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h
index 97934ccba5b1..e53c32362774 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.h
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h
@@ -393,7 +393,7 @@  struct stmmac_ops {
 			     struct stmmac_rss *cfg, u32 num_rxq);
 	/* VLAN */
 	void (*update_vlan_hash)(struct mac_device_info *hw, u32 hash,
-				 __le16 perfect_match, bool is_double);
+				 u16 perfect_match, bool is_double);
 	void (*enable_vlan)(struct mac_device_info *hw, u32 type);
 	void (*rx_hw_vlan)(struct mac_device_info *hw, struct dma_desc *rx_desc,
 			   struct sk_buff *skb);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 4b6a359e5a94..12689774d755 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -6641,7 +6641,7 @@  static u32 stmmac_vid_crc32_le(__le16 vid_le)
 static int stmmac_vlan_update(struct stmmac_priv *priv, bool is_double)
 {
 	u32 crc, hash = 0;
-	__le16 pmatch = 0;
+	u16 pmatch = 0;
 	int count = 0;
 	u16 vid = 0;
 
@@ -6656,7 +6656,7 @@  static int stmmac_vlan_update(struct stmmac_priv *priv, bool is_double)
 		if (count > 2) /* VID = 0 always passes filter */
 			return -EOPNOTSUPP;
 
-		pmatch = cpu_to_le16(vid);
+		pmatch = vid;
 		hash = 0;
 	}