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/md/dm-path-selector.c | 138 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 138 insertions(+) create mode 100644 drivers/md/dm-path-selector.c (limited to 'drivers/md/dm-path-selector.c') diff --git a/drivers/md/dm-path-selector.c b/drivers/md/dm-path-selector.c new file mode 100644 index 000000000..006a7991f --- /dev/null +++ b/drivers/md/dm-path-selector.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2003 Sistina Software. + * Copyright (C) 2004 Red Hat, Inc. All rights reserved. + * + * Module Author: Heinz Mauelshagen + * + * This file is released under the GPL. + * + * Path selector registration. + */ + +#include +#include + +#include "dm-path-selector.h" + +#include + +struct ps_internal { + struct path_selector_type pst; + struct list_head list; +}; + +#define pst_to_psi(__pst) container_of((__pst), struct ps_internal, pst) + +static LIST_HEAD(_path_selectors); +static DECLARE_RWSEM(_ps_lock); + +static struct ps_internal *__find_path_selector_type(const char *name) +{ + struct ps_internal *psi; + + list_for_each_entry(psi, &_path_selectors, list) { + if (!strcmp(name, psi->pst.name)) + return psi; + } + + return NULL; +} + +static struct ps_internal *get_path_selector(const char *name) +{ + struct ps_internal *psi; + + down_read(&_ps_lock); + psi = __find_path_selector_type(name); + if (psi && !try_module_get(psi->pst.module)) + psi = NULL; + up_read(&_ps_lock); + + return psi; +} + +struct path_selector_type *dm_get_path_selector(const char *name) +{ + struct ps_internal *psi; + + if (!name) + return NULL; + + psi = get_path_selector(name); + if (!psi) { + request_module("dm-%s", name); + psi = get_path_selector(name); + } + + return psi ? &psi->pst : NULL; +} + +void dm_put_path_selector(struct path_selector_type *pst) +{ + struct ps_internal *psi; + + if (!pst) + return; + + down_read(&_ps_lock); + psi = __find_path_selector_type(pst->name); + if (!psi) + goto out; + + module_put(psi->pst.module); +out: + up_read(&_ps_lock); +} + +static struct ps_internal *_alloc_path_selector(struct path_selector_type *pst) +{ + struct ps_internal *psi = kzalloc_obj(*psi); + + if (psi) + psi->pst = *pst; + + return psi; +} + +int dm_register_path_selector(struct path_selector_type *pst) +{ + int r = 0; + struct ps_internal *psi = _alloc_path_selector(pst); + + if (!psi) + return -ENOMEM; + + down_write(&_ps_lock); + + if (__find_path_selector_type(pst->name)) { + kfree(psi); + r = -EBUSY; + } else + list_add(&psi->list, &_path_selectors); + + up_write(&_ps_lock); + + return r; +} +EXPORT_SYMBOL_GPL(dm_register_path_selector); + +void dm_unregister_path_selector(struct path_selector_type *pst) +{ + struct ps_internal *psi; + + down_write(&_ps_lock); + + psi = __find_path_selector_type(pst->name); + if (WARN_ON(!psi)) { + up_write(&_ps_lock); + return; + } + + list_del(&psi->list); + + up_write(&_ps_lock); + + kfree(psi); +} +EXPORT_SYMBOL_GPL(dm_unregister_path_selector); -- cgit v1.3.1