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/seccomp/bpf-helper.c | 96 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 96 insertions(+) create mode 100644 samples/seccomp/bpf-helper.c (limited to 'samples/seccomp/bpf-helper.c') diff --git a/samples/seccomp/bpf-helper.c b/samples/seccomp/bpf-helper.c new file mode 100644 index 000000000..ae260d77a --- /dev/null +++ b/samples/seccomp/bpf-helper.c @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Seccomp BPF helper functions + * + * Copyright (c) 2012 The Chromium OS Authors + * Author: Will Drewry + * + * The code may be used by anyone for any purpose, + * and can serve as a starting point for developing + * applications using prctl(PR_ATTACH_SECCOMP_FILTER). + */ + +#include +#include +#include + +#include "bpf-helper.h" + +int bpf_resolve_jumps(struct bpf_labels *labels, + struct sock_filter *filter, size_t count) +{ + size_t i; + + if (count < 1 || count > BPF_MAXINSNS) + return -1; + /* + * Walk it once, backwards, to build the label table and do fixups. + * Since backward jumps are disallowed by BPF, this is easy. + */ + for (i = 0; i < count; ++i) { + size_t offset = count - i - 1; + struct sock_filter *instr = &filter[offset]; + if (instr->code != (BPF_JMP+BPF_JA)) + continue; + switch ((instr->jt<<8)|instr->jf) { + case (JUMP_JT<<8)|JUMP_JF: + if (labels->labels[instr->k].location == 0xffffffff) { + fprintf(stderr, "Unresolved label: '%s'\n", + labels->labels[instr->k].label); + return 1; + } + instr->k = labels->labels[instr->k].location - + (offset + 1); + instr->jt = 0; + instr->jf = 0; + continue; + case (LABEL_JT<<8)|LABEL_JF: + if (labels->labels[instr->k].location != 0xffffffff) { + fprintf(stderr, "Duplicate label use: '%s'\n", + labels->labels[instr->k].label); + return 1; + } + labels->labels[instr->k].location = offset; + instr->k = 0; /* fall through */ + instr->jt = 0; + instr->jf = 0; + continue; + } + } + return 0; +} + +/* Simple lookup table for labels. */ +__u32 seccomp_bpf_label(struct bpf_labels *labels, const char *label) +{ + struct __bpf_label *begin = labels->labels, *end; + int id; + + if (labels->count == BPF_LABELS_MAX) { + fprintf(stderr, "Too many labels\n"); + exit(1); + } + if (labels->count == 0) { + begin->label = label; + begin->location = 0xffffffff; + labels->count++; + return 0; + } + end = begin + labels->count; + for (id = 0; begin < end; ++begin, ++id) { + if (!strcmp(label, begin->label)) + return id; + } + begin->label = label; + begin->location = 0xffffffff; + labels->count++; + return id; +} + +void seccomp_bpf_print(struct sock_filter *filter, size_t count) +{ + struct sock_filter *end = filter + count; + for ( ; filter < end; ++filter) + printf("{ code=%u,jt=%u,jf=%u,k=%u },\n", + filter->code, filter->jt, filter->jf, filter->k); +} -- cgit v1.3.1