From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- include/net/gso.h | 109 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) create mode 100644 include/net/gso.h (limited to 'include/net/gso.h') diff --git a/include/net/gso.h b/include/net/gso.h new file mode 100644 index 000000000..29975440c --- /dev/null +++ b/include/net/gso.h @@ -0,0 +1,109 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ + +#ifndef _NET_GSO_H +#define _NET_GSO_H + +#include + +/* Keeps track of mac header offset relative to skb->head. + * It is useful for TSO of Tunneling protocol. e.g. GRE. + * For non-tunnel skb it points to skb_mac_header() and for + * tunnel skb it points to outer mac header. + * Keeps track of level of encapsulation of network headers. + */ +struct skb_gso_cb { + union { + int mac_offset; + int data_offset; + }; + int encap_level; + __wsum csum; + __u16 csum_start; +}; +#define SKB_GSO_CB_OFFSET 32 +#define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_GSO_CB_OFFSET)) + +static inline int skb_tnl_header_len(const struct sk_buff *inner_skb) +{ + return (skb_mac_header(inner_skb) - inner_skb->head) - + SKB_GSO_CB(inner_skb)->mac_offset; +} + +static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra) +{ + int new_headroom, headroom; + int ret; + + headroom = skb_headroom(skb); + ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC); + if (ret) + return ret; + + new_headroom = skb_headroom(skb); + SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom); + return 0; +} + +static inline void gso_reset_checksum(struct sk_buff *skb, __wsum res) +{ + /* Do not update partial checksums if remote checksum is enabled. */ + if (skb->remcsum_offload) + return; + + SKB_GSO_CB(skb)->csum = res; + SKB_GSO_CB(skb)->csum_start = skb_checksum_start(skb) - skb->head; +} + +/* Compute the checksum for a gso segment. First compute the checksum value + * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and + * then add in skb->csum (checksum from csum_start to end of packet). + * skb->csum and csum_start are then updated to reflect the checksum of the + * resultant packet starting from the transport header-- the resultant checksum + * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo + * header. + */ +static inline __sum16 gso_make_checksum(struct sk_buff *skb, __wsum res) +{ + unsigned char *csum_start = skb_transport_header(skb); + int plen = (skb->head + SKB_GSO_CB(skb)->csum_start) - csum_start; + __wsum partial = SKB_GSO_CB(skb)->csum; + + SKB_GSO_CB(skb)->csum = res; + SKB_GSO_CB(skb)->csum_start = csum_start - skb->head; + + return csum_fold(csum_partial(csum_start, plen, partial)); +} + +struct sk_buff *__skb_gso_segment(struct sk_buff *skb, + netdev_features_t features, bool tx_path); + +static inline struct sk_buff *skb_gso_segment(struct sk_buff *skb, + netdev_features_t features) +{ + return __skb_gso_segment(skb, features, true); +} + +struct sk_buff *skb_eth_gso_segment(struct sk_buff *skb, + netdev_features_t features, __be16 type); + +struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb, + netdev_features_t features); + +bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu); + +bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len); + +static inline void skb_gso_error_unwind(struct sk_buff *skb, __be16 protocol, + int pulled_hlen, u16 mac_offset, + int mac_len) +{ + skb->protocol = protocol; + skb->encapsulation = 1; + skb_push(skb, pulled_hlen); + skb_reset_transport_header(skb); + skb->mac_header = mac_offset; + skb->network_header = skb->mac_header + mac_len; + skb->mac_len = mac_len; +} + +#endif /* _NET_GSO_H */ -- cgit v1.3.1