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 --- io_uring/alloc_cache.h | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 io_uring/alloc_cache.h (limited to 'io_uring/alloc_cache.h') diff --git a/io_uring/alloc_cache.h b/io_uring/alloc_cache.h new file mode 100644 index 000000000..962b6e2d0 --- /dev/null +++ b/io_uring/alloc_cache.h @@ -0,0 +1,70 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef IOU_ALLOC_CACHE_H +#define IOU_ALLOC_CACHE_H + +#include +#include + +/* + * Don't allow the cache to grow beyond this size. + */ +#define IO_ALLOC_CACHE_MAX 128 + +void io_alloc_cache_free(struct io_alloc_cache *cache, + void (*free)(const void *)); +bool io_alloc_cache_init(struct io_alloc_cache *cache, + unsigned max_nr, unsigned int size, + unsigned int init_bytes); + +void *io_cache_alloc_new(struct io_alloc_cache *cache, gfp_t gfp); + +static inline bool io_alloc_cache_put(struct io_alloc_cache *cache, + void *entry) +{ + if (cache->nr_cached < cache->max_cached) { + if (!kasan_mempool_poison_object(entry)) + return false; + cache->entries[cache->nr_cached++] = entry; + return true; + } + return false; +} + +static inline void *io_alloc_cache_get(struct io_alloc_cache *cache) +{ + if (cache->nr_cached) { + void *entry = cache->entries[--cache->nr_cached]; + + /* + * If KASAN is enabled, always clear the initial bytes that + * must be zeroed post alloc, in case any of them overlap + * with KASAN storage. + */ +#if defined(CONFIG_KASAN) + kasan_mempool_unpoison_object(entry, cache->elem_size); + if (cache->init_clear) + memset(entry, 0, cache->init_clear); +#endif + return entry; + } + + return NULL; +} + +static inline void *io_cache_alloc(struct io_alloc_cache *cache, gfp_t gfp) +{ + void *obj; + + obj = io_alloc_cache_get(cache); + if (obj) + return obj; + return io_cache_alloc_new(cache, gfp); +} + +static inline void io_cache_free(struct io_alloc_cache *cache, void *obj) +{ + if (!io_alloc_cache_put(cache, obj)) + kvfree(obj); +} + +#endif -- cgit v1.3.1