From 2de1ba0887e5d3bf02d7c212f380039b34e10aa3 Mon Sep 17 00:00:00 2001 From: Gal Pressman Date: Mon, 16 Jun 2025 16:26:24 +0300 Subject: net: vlan: Make is_vlan_dev() a stub when VLAN is not configured Add a stub implementation of is_vlan_dev() that returns false when VLAN support is not compiled in (CONFIG_VLAN_8021Q=n). This allows us to compile-out VLAN-dependent dead code when it is not needed. This also resolves the following compilation error when: * CONFIG_VLAN_8021Q=n * CONFIG_OBJTOOL=y * CONFIG_OBJTOOL_WERROR=y drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.o: error: objtool: parse_mirred.isra.0+0x370: mlx5e_tc_act_vlan_add_push_action() missing __noreturn in .c/.h or NORETURN() in noreturns.h The error occurs because objtool cannot determine that unreachable BUG() (which doesn't return) calls in VLAN code paths are actually dead code when VLAN support is disabled. Signed-off-by: Gal Pressman Link: https://patch.msgid.link/20250616132626.1749331-2-gal@nvidia.com Signed-off-by: Jakub Kicinski --- include/linux/if_vlan.h | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index 38456b42cdb5..618a973ff8ee 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -79,11 +79,6 @@ static inline struct vlan_ethhdr *skb_vlan_eth_hdr(const struct sk_buff *skb) /* found in socket.c */ extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *)); -static inline bool is_vlan_dev(const struct net_device *dev) -{ - return dev->priv_flags & IFF_802_1Q_VLAN; -} - #define skb_vlan_tag_present(__skb) (!!(__skb)->vlan_all) #define skb_vlan_tag_get(__skb) ((__skb)->vlan_tci) #define skb_vlan_tag_get_id(__skb) ((__skb)->vlan_tci & VLAN_VID_MASK) @@ -200,6 +195,11 @@ struct vlan_dev_priv { #endif }; +static inline bool is_vlan_dev(const struct net_device *dev) +{ + return dev->priv_flags & IFF_802_1Q_VLAN; +} + static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev) { return netdev_priv(dev); @@ -237,6 +237,11 @@ extern void vlan_vids_del_by_dev(struct net_device *dev, extern bool vlan_uses_dev(const struct net_device *dev); #else +static inline bool is_vlan_dev(const struct net_device *dev) +{ + return false; +} + static inline struct net_device * __vlan_find_dev_deep_rcu(struct net_device *real_dev, __be16 vlan_proto, u16 vlan_id) -- cgit v1.2.3 From 60a8b1a5d0824afda869f18dc0ecfe72f8dfda42 Mon Sep 17 00:00:00 2001 From: Gal Pressman Date: Mon, 16 Jun 2025 16:26:25 +0300 Subject: net: vlan: Replace BUG() with WARN_ON_ONCE() in vlan_dev_* stubs When CONFIG_VLAN_8021Q=n, a set of stub helpers are used, three of these helpers use BUG() unconditionally. This code should not be reached, as callers of these functions should always check for is_vlan_dev() first, but the usage of BUG() is not recommended, replace it with WARN_ON() instead. Reviewed-by: Alex Lazar Reviewed-by: Dragos Tatulea Signed-off-by: Gal Pressman Link: https://patch.msgid.link/20250616132626.1749331-3-gal@nvidia.com Signed-off-by: Jakub Kicinski --- include/linux/if_vlan.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index 618a973ff8ee..b9f699799cf6 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -259,19 +259,19 @@ vlan_for_each(struct net_device *dev, static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev) { - BUG(); + WARN_ON_ONCE(1); return NULL; } static inline u16 vlan_dev_vlan_id(const struct net_device *dev) { - BUG(); + WARN_ON_ONCE(1); return 0; } static inline __be16 vlan_dev_vlan_proto(const struct net_device *dev) { - BUG(); + WARN_ON_ONCE(1); return 0; } -- cgit v1.2.3 From 9c5f5a5bf0da5cee2044b93907ac6d8d9af0492b Mon Sep 17 00:00:00 2001 From: Gal Pressman Date: Mon, 16 Jun 2025 16:26:26 +0300 Subject: net: vlan: Use IS_ENABLED() helper for CONFIG_VLAN_8021Q guard MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The header currently tests the VLAN core with an explicit pair of 'if defined' checks: #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) Instead, use IS_ENABLED() which is the kernel way to test whether an option is configured as builtin/module. This is purely cosmetic – no functional changes. Reviewed-by: Alex Lazar Reviewed-by: Dragos Tatulea Signed-off-by: Gal Pressman Link: https://patch.msgid.link/20250616132626.1749331-4-gal@nvidia.com Signed-off-by: Jakub Kicinski --- include/linux/if_vlan.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index b9f699799cf6..15e01935d3fa 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -131,7 +131,7 @@ struct vlan_pcpu_stats { u32 tx_dropped; }; -#if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) +#if IS_ENABLED(CONFIG_VLAN_8021Q) extern struct net_device *__vlan_find_dev_deep_rcu(struct net_device *real_dev, __be16 vlan_proto, u16 vlan_id); -- cgit v1.2.3