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/dst_ops.h | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 include/net/dst_ops.h (limited to 'include/net/dst_ops.h') diff --git a/include/net/dst_ops.h b/include/net/dst_ops.h new file mode 100644 index 000000000..3a9001a04 --- /dev/null +++ b/include/net/dst_ops.h @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _NET_DST_OPS_H +#define _NET_DST_OPS_H +#include +#include +#include + +struct dst_entry; +struct kmem_cachep; +struct net_device; +struct sk_buff; +struct sock; +struct net; + +struct dst_ops { + unsigned short family; + unsigned int gc_thresh; + + void (*gc)(struct dst_ops *ops); + struct dst_entry * (*check)(struct dst_entry *, __u32 cookie); + unsigned int (*default_advmss)(const struct dst_entry *); + unsigned int (*mtu)(const struct dst_entry *); + u32 * (*cow_metrics)(struct dst_entry *, unsigned long); + void (*destroy)(struct dst_entry *); + void (*ifdown)(struct dst_entry *, + struct net_device *dev); + void (*negative_advice)(struct sock *sk, struct dst_entry *); + void (*link_failure)(struct sk_buff *); + void (*update_pmtu)(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb, u32 mtu, + bool confirm_neigh); + void (*redirect)(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb); + int (*local_out)(struct net *net, struct sock *sk, struct sk_buff *skb); + struct neighbour * (*neigh_lookup)(const struct dst_entry *dst, + struct sk_buff *skb, + const void *daddr); + void (*confirm_neigh)(const struct dst_entry *dst, + const void *daddr); + + struct kmem_cache *kmem_cachep; + + struct percpu_counter pcpuc_entries ____cacheline_aligned_in_smp; +}; + +static inline int dst_entries_get_fast(struct dst_ops *dst) +{ + return percpu_counter_read_positive(&dst->pcpuc_entries); +} + +static inline int dst_entries_get_slow(struct dst_ops *dst) +{ + return percpu_counter_sum_positive(&dst->pcpuc_entries); +} + +#define DST_PERCPU_COUNTER_BATCH 32 +static inline void dst_entries_add(struct dst_ops *dst, int val) +{ + percpu_counter_add_batch(&dst->pcpuc_entries, val, + DST_PERCPU_COUNTER_BATCH); +} + +static inline int dst_entries_init(struct dst_ops *dst) +{ + return percpu_counter_init(&dst->pcpuc_entries, 0, GFP_KERNEL); +} + +static inline void dst_entries_destroy(struct dst_ops *dst) +{ + percpu_counter_destroy(&dst->pcpuc_entries); +} + +#endif -- cgit v1.3.1