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 --- drivers/perf/arm_brbe.h | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 drivers/perf/arm_brbe.h (limited to 'drivers/perf/arm_brbe.h') diff --git a/drivers/perf/arm_brbe.h b/drivers/perf/arm_brbe.h new file mode 100644 index 000000000..b7c7d8796 --- /dev/null +++ b/drivers/perf/arm_brbe.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Branch Record Buffer Extension Helpers. + * + * Copyright (C) 2022-2025 ARM Limited + * + * Author: Anshuman Khandual + */ + +struct arm_pmu; +struct perf_branch_stack; +struct perf_event; + +#ifdef CONFIG_ARM64_BRBE +void brbe_probe(struct arm_pmu *arm_pmu); +unsigned int brbe_num_branch_records(const struct arm_pmu *armpmu); +void brbe_invalidate(void); + +void brbe_enable(const struct arm_pmu *arm_pmu); +void brbe_disable(void); + +bool brbe_branch_attr_valid(struct perf_event *event); +void brbe_read_filtered_entries(struct perf_branch_stack *branch_stack, + const struct perf_event *event); +#else +static inline void brbe_probe(struct arm_pmu *arm_pmu) { } +static inline unsigned int brbe_num_branch_records(const struct arm_pmu *armpmu) +{ + return 0; +} + +static inline void brbe_invalidate(void) { } + +static inline void brbe_enable(const struct arm_pmu *arm_pmu) { }; +static inline void brbe_disable(void) { }; + +static inline bool brbe_branch_attr_valid(struct perf_event *event) +{ + WARN_ON_ONCE(!has_branch_stack(event)); + return false; +} + +static void brbe_read_filtered_entries(struct perf_branch_stack *branch_stack, + const struct perf_event *event) +{ +} +#endif -- cgit v1.3.1