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 --- samples/bpf/spintest_user.c | 84 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 samples/bpf/spintest_user.c (limited to 'samples/bpf/spintest_user.c') diff --git a/samples/bpf/spintest_user.c b/samples/bpf/spintest_user.c new file mode 100644 index 000000000..55971edb1 --- /dev/null +++ b/samples/bpf/spintest_user.c @@ -0,0 +1,84 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include "trace_helpers.h" + +int main(int ac, char **argv) +{ + struct bpf_object *obj = NULL; + struct bpf_link *links[20]; + long key, next_key, value; + struct bpf_program *prog; + int map_fd, i, j = 0; + char filename[256]; + struct ksym *sym; + + if (load_kallsyms()) { + printf("failed to process /proc/kallsyms\n"); + return 2; + } + + snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]); + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + obj = NULL; + goto cleanup; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } + + map_fd = bpf_object__find_map_fd_by_name(obj, "my_map"); + if (map_fd < 0) { + fprintf(stderr, "ERROR: finding a map in obj file failed\n"); + goto cleanup; + } + + bpf_object__for_each_program(prog, obj) { + links[j] = bpf_program__attach(prog); + if (libbpf_get_error(links[j])) { + fprintf(stderr, "bpf_program__attach failed\n"); + links[j] = NULL; + goto cleanup; + } + j++; + } + + for (i = 0; i < 5; i++) { + key = 0; + printf("kprobing funcs:"); + while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) { + bpf_map_lookup_elem(map_fd, &next_key, &value); + assert(next_key == value); + sym = ksym_search(value); + key = next_key; + if (!sym) { + printf("ksym not found. Is kallsyms loaded?\n"); + continue; + } + + printf(" %s", sym->name); + } + if (key) + printf("\n"); + key = 0; + while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) + bpf_map_delete_elem(map_fd, &next_key); + sleep(1); + } + +cleanup: + for (j--; j >= 0; j--) + bpf_link__destroy(links[j]); + + bpf_object__close(obj); + return 0; +} -- cgit v1.3.1