From 3849687869092094003ba009dc00e2e0237a3b8a Mon Sep 17 00:00:00 2001 From: Maxime Chevallier Date: Wed, 21 Aug 2024 17:09:55 +0200 Subject: net: phy: Introduce ethernet link topology representation Link topologies containing multiple network PHYs attached to the same net_device can be found when using a PHY as a media converter for use with an SFP connector, on which an SFP transceiver containing a PHY can be used. With the current model, the transceiver's PHY can't be used for operations such as cable testing, timestamping, macsec offload, etc. The reason being that most of the logic for these configuration, coming from either ethtool netlink or ioctls tend to use netdev->phydev, which in multi-phy systems will reference the PHY closest to the MAC. Introduce a numbering scheme allowing to enumerate PHY devices that belong to any netdev, which can in turn allow userspace to take more precise decisions with regard to each PHY's configuration. The numbering is maintained per-netdev, in a phy_device_list. The numbering works similarly to a netdevice's ifindex, with identifiers that are only recycled once INT_MAX has been reached. This prevents races that could occur between PHY listing and SFP transceiver removal/insertion. The identifiers are assigned at phy_attach time, as the numbering depends on the netdevice the phy is attached to. The PHY index can be re-used for PHYs that are persistent. Signed-off-by: Maxime Chevallier Reviewed-by: Christophe Leroy Tested-by: Christophe Leroy Signed-off-by: David S. Miller --- include/uapi/linux/ethtool.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include/uapi/linux/ethtool.h') diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h index 4a0a6e703483..c405ed63acfa 100644 --- a/include/uapi/linux/ethtool.h +++ b/include/uapi/linux/ethtool.h @@ -2533,4 +2533,20 @@ struct ethtool_link_settings { * __u32 map_lp_advertising[link_mode_masks_nwords]; */ }; + +/** + * enum phy_upstream - Represents the upstream component a given PHY device + * is connected to, as in what is on the other end of the MII bus. Most PHYs + * will be attached to an Ethernet MAC controller, but in some cases, there's + * an intermediate PHY used as a media-converter, which will driver another + * MII interface as its output. + * @PHY_UPSTREAM_MAC: Upstream component is a MAC (a switch port, + * or ethernet controller) + * @PHY_UPSTREAM_PHY: Upstream component is a PHY (likely a media converter) + */ +enum phy_upstream { + PHY_UPSTREAM_MAC, + PHY_UPSTREAM_PHY, +}; + #endif /* _UAPI_LINUX_ETHTOOL_H */ -- cgit v1.2.3 From 43d3487035e9a86fad952de4240a518614240d43 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Tue, 29 Oct 2024 15:55:35 -0600 Subject: UAPI: ethtool: Use __struct_group() in struct ethtool_link_settings Use the `__struct_group()` helper to create a new tagged `struct ethtool_link_settings_hdr`. This structure groups together all the members of the flexible `struct ethtool_link_settings` except the flexible array. As a result, the array is effectively separated from the rest of the members without modifying the memory layout of the flexible structure. This new tagged struct will be used to fix problematic declarations of middle-flex-arrays in composite structs[1]. [1] https://git.kernel.org/linus/d88cabfd9abc Signed-off-by: Gustavo A. R. Silva Link: https://patch.msgid.link/9e9fb0bd72e5ba1e916acbb4995b1e358b86a689.1730238285.git.gustavoars@kernel.org Signed-off-by: Jakub Kicinski --- include/uapi/linux/ethtool.h | 33 ++++++++++++++++++--------------- 1 file changed, 18 insertions(+), 15 deletions(-) (limited to 'include/uapi/linux/ethtool.h') diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h index c405ed63acfa..fc1f54b065f9 100644 --- a/include/uapi/linux/ethtool.h +++ b/include/uapi/linux/ethtool.h @@ -2511,21 +2511,24 @@ enum ethtool_reset_flags { * autonegotiation; 0 if unknown or not applicable. Read-only. */ struct ethtool_link_settings { - __u32 cmd; - __u32 speed; - __u8 duplex; - __u8 port; - __u8 phy_address; - __u8 autoneg; - __u8 mdio_support; - __u8 eth_tp_mdix; - __u8 eth_tp_mdix_ctrl; - __s8 link_mode_masks_nwords; - __u8 transceiver; - __u8 master_slave_cfg; - __u8 master_slave_state; - __u8 rate_matching; - __u32 reserved[7]; + /* New members MUST be added within the __struct_group() macro below. */ + __struct_group(ethtool_link_settings_hdr, hdr, /* no attrs */, + __u32 cmd; + __u32 speed; + __u8 duplex; + __u8 port; + __u8 phy_address; + __u8 autoneg; + __u8 mdio_support; + __u8 eth_tp_mdix; + __u8 eth_tp_mdix_ctrl; + __s8 link_mode_masks_nwords; + __u8 transceiver; + __u8 master_slave_cfg; + __u8 master_slave_state; + __u8 rate_matching; + __u32 reserved[7]; + ); __u32 link_mode_masks[]; /* layout of link_mode_masks fields: * __u32 map_supported[link_mode_masks_nwords]; -- cgit v1.2.3 From ebda123fe703f492d7d557a4da00888ddec4779e Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 15 Nov 2024 12:43:04 -0800 Subject: Revert "UAPI: ethtool: Use __struct_group() in struct ethtool_link_settings" This reverts commit 43d3487035e9a86fad952de4240a518614240d43. We cannot use tagged struct groups in UAPI because C++ will throw syntax errors even under "extern C". Signed-off-by: Kees Cook Link: https://patch.msgid.link/20241115204308.3821419-2-kees@kernel.org Signed-off-by: Jakub Kicinski --- include/uapi/linux/ethtool.h | 33 +++++++++++++++------------------ 1 file changed, 15 insertions(+), 18 deletions(-) (limited to 'include/uapi/linux/ethtool.h') diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h index fc1f54b065f9..c405ed63acfa 100644 --- a/include/uapi/linux/ethtool.h +++ b/include/uapi/linux/ethtool.h @@ -2511,24 +2511,21 @@ enum ethtool_reset_flags { * autonegotiation; 0 if unknown or not applicable. Read-only. */ struct ethtool_link_settings { - /* New members MUST be added within the __struct_group() macro below. */ - __struct_group(ethtool_link_settings_hdr, hdr, /* no attrs */, - __u32 cmd; - __u32 speed; - __u8 duplex; - __u8 port; - __u8 phy_address; - __u8 autoneg; - __u8 mdio_support; - __u8 eth_tp_mdix; - __u8 eth_tp_mdix_ctrl; - __s8 link_mode_masks_nwords; - __u8 transceiver; - __u8 master_slave_cfg; - __u8 master_slave_state; - __u8 rate_matching; - __u32 reserved[7]; - ); + __u32 cmd; + __u32 speed; + __u8 duplex; + __u8 port; + __u8 phy_address; + __u8 autoneg; + __u8 mdio_support; + __u8 eth_tp_mdix; + __u8 eth_tp_mdix_ctrl; + __s8 link_mode_masks_nwords; + __u8 transceiver; + __u8 master_slave_cfg; + __u8 master_slave_state; + __u8 rate_matching; + __u32 reserved[7]; __u32 link_mode_masks[]; /* layout of link_mode_masks fields: * __u32 map_supported[link_mode_masks_nwords]; -- cgit v1.2.3 From 96c677fca54a28fcfea4dbab9c1f2530bd0a08d1 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 15 Nov 2024 12:43:05 -0800 Subject: UAPI: ethtool: Avoid flex-array in struct ethtool_link_settings struct ethtool_link_settings tends to be used as a header for other structures that have trailing bytes[1], but has a trailing flexible array itself. Using this overlapped with other structures leads to ambiguous object sizing in the compiler, so we want to avoid such situations (which have caused real bugs in the past). Detecting this can be done with -Wflex-array-member-not-at-end, which will need to be enabled globally. Using a tagged struct_group() to create a new ethtool_link_settings_hdr structure isn't possible as it seems we cannot use the tagged variant of struct_group() due to syntax issues from C++'s perspective (even within "extern C")[2]. Instead, we can just leave the offending member defined in UAPI and remove it from the kernel's view of the structure, as Linux doesn't actually use this member at all. There is also no change in size since it was already a flexible array that didn't contribute to size returned by any use of sizeof(). Reported-by: Jakub Kicinski Closes: https://lore.kernel.org/lkml/20241109100213.262a2fa0@kernel.org/ [2] Link: https://lore.kernel.org/lkml/0bc2809fe2a6c11dd4c8a9a10d9bd65cccdb559b.1730238285.git.gustavoars@kernel.org/ [1] Signed-off-by: Kees Cook Reviewed-by: Jakub Kicinski Link: https://patch.msgid.link/20241115204308.3821419-3-kees@kernel.org Signed-off-by: Jakub Kicinski --- include/uapi/linux/ethtool.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/uapi/linux/ethtool.h') diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h index c405ed63acfa..7e1b3820f91f 100644 --- a/include/uapi/linux/ethtool.h +++ b/include/uapi/linux/ethtool.h @@ -2526,12 +2526,19 @@ struct ethtool_link_settings { __u8 master_slave_state; __u8 rate_matching; __u32 reserved[7]; +#ifndef __KERNEL__ + /* Linux builds with -Wflex-array-member-not-at-end but does + * not use the "link_mode_masks" member. Leave it defined for + * userspace for now, and when userspace wants to start using + * -Wfamnae, we'll need a new solution. + */ __u32 link_mode_masks[]; /* layout of link_mode_masks fields: * __u32 map_supported[link_mode_masks_nwords]; * __u32 map_advertising[link_mode_masks_nwords]; * __u32 map_lp_advertising[link_mode_masks_nwords]; */ +#endif }; /** -- cgit v1.2.3