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/cls_cgroup.h | 88 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 include/net/cls_cgroup.h (limited to 'include/net/cls_cgroup.h') diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h new file mode 100644 index 000000000..668aeee9b --- /dev/null +++ b/include/net/cls_cgroup.h @@ -0,0 +1,88 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * cls_cgroup.h Control Group Classifier + * + * Authors: Thomas Graf + */ + +#ifndef _NET_CLS_CGROUP_H +#define _NET_CLS_CGROUP_H + +#include +#include +#include +#include +#include + +#ifdef CONFIG_CGROUP_NET_CLASSID +struct cgroup_cls_state { + struct cgroup_subsys_state css; + u32 classid; +}; + +struct cgroup_cls_state *task_cls_state(struct task_struct *p); + +static inline u32 task_cls_classid(struct task_struct *p) +{ + u32 classid; + + if (in_interrupt()) + return 0; + + rcu_read_lock(); + classid = container_of(task_css(p, net_cls_cgrp_id), + struct cgroup_cls_state, css)->classid; + rcu_read_unlock(); + + return classid; +} + +static inline void sock_update_classid(struct sock_cgroup_data *skcd) +{ + u32 classid; + + classid = task_cls_classid(current); + sock_cgroup_set_classid(skcd, classid); +} + +static inline u32 __task_get_classid(struct task_struct *task) +{ + return task_cls_state(task)->classid; +} + +static inline u32 task_get_classid(const struct sk_buff *skb) +{ + u32 classid = __task_get_classid(current); + + /* Due to the nature of the classifier it is required to ignore all + * packets originating from softirq context as accessing `current' + * would lead to false results. + * + * This test assumes that all callers of dev_queue_xmit() explicitly + * disable bh. Knowing this, it is possible to detect softirq based + * calls by looking at the number of nested bh disable calls because + * softirqs always disables bh. + */ + if (softirq_count()) { + struct sock *sk = skb_to_full_sk(skb); + + /* If there is an sock_cgroup_classid we'll use that. */ + if (!sk || !sk_fullsock(sk)) + return 0; + + classid = sock_cgroup_classid(&sk->sk_cgrp_data); + } + + return classid; +} +#else /* !CONFIG_CGROUP_NET_CLASSID */ +static inline void sock_update_classid(struct sock_cgroup_data *skcd) +{ +} + +static inline u32 task_get_classid(const struct sk_buff *skb) +{ + return 0; +} +#endif /* CONFIG_CGROUP_NET_CLASSID */ +#endif /* _NET_CLS_CGROUP_H */ -- cgit v1.3.1