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 --- tools/testing/radix-tree/regression4.c | 79 ++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 tools/testing/radix-tree/regression4.c (limited to 'tools/testing/radix-tree/regression4.c') diff --git a/tools/testing/radix-tree/regression4.c b/tools/testing/radix-tree/regression4.c new file mode 100644 index 000000000..cf4e5aba6 --- /dev/null +++ b/tools/testing/radix-tree/regression4.c @@ -0,0 +1,79 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "regression.h" + +static pthread_barrier_t worker_barrier; +static int obj0, obj1; +static RADIX_TREE(mt_tree, GFP_KERNEL); + +static void *reader_fn(void *arg) +{ + int i; + void *entry; + + rcu_register_thread(); + pthread_barrier_wait(&worker_barrier); + + for (i = 0; i < 1000000; i++) { + rcu_read_lock(); + entry = radix_tree_lookup(&mt_tree, 0); + rcu_read_unlock(); + if (entry != &obj0) { + printf("iteration %d bad entry = %p\n", i, entry); + abort(); + } + } + + rcu_unregister_thread(); + + return NULL; +} + +static void *writer_fn(void *arg) +{ + int i; + + rcu_register_thread(); + pthread_barrier_wait(&worker_barrier); + + for (i = 0; i < 1000000; i++) { + radix_tree_insert(&mt_tree, 1, &obj1); + radix_tree_delete(&mt_tree, 1); + } + + rcu_unregister_thread(); + + return NULL; +} + +void regression4_test(void) +{ + pthread_t reader, writer; + + printv(1, "regression test 4 starting\n"); + + radix_tree_insert(&mt_tree, 0, &obj0); + pthread_barrier_init(&worker_barrier, NULL, 2); + + if (pthread_create(&reader, NULL, reader_fn, NULL) || + pthread_create(&writer, NULL, writer_fn, NULL)) { + perror("pthread_create"); + exit(1); + } + + if (pthread_join(reader, NULL) || pthread_join(writer, NULL)) { + perror("pthread_join"); + exit(1); + } + + printv(1, "regression test 4 passed\n"); +} -- cgit v1.3.1