diff options
| author | Yazen Ghannam <yazen.ghannam@amd.com> | 2026-09-03 10:43:25 -0500 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2026-09-10 18:05:43 -0700 |
| commit | 27600805e62f800bacf990354632eae4e487d34c (patch) | |
| tree | e8aec0ddfaa0bc264d79af632e3de3f1b75ae4c8 | |
| parent | f65d38155aef069c897a64643a03db237dd1e0c8 (diff) | |
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 <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com
| -rw-r--r-- | arch/x86/kernel/amd_node.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/x86/kernel/amd_node.c b/arch/x86/kernel/amd_node.c index 762585775b5a..b7926ba3610a 100644 --- a/arch/x86/kernel/amd_node.c +++ b/arch/x86/kernel/amd_node.c @@ -251,7 +251,7 @@ __setup("amd_smn_debugfs_enable", amd_smn_enable_dfs); static int __init amd_smn_init(void) { u16 count, num_roots, roots_per_node, node, num_nodes; - struct pci_dev *root; + struct pci_dev *root __free(pci_dev_put) = NULL; if (!cpu_feature_enabled(X86_FEATURE_ZEN)) return 0; @@ -262,7 +262,6 @@ static int __init amd_smn_init(void) return 0; num_roots = 0; - root = NULL; while ((root = get_next_root(root))) { pci_dbg(root, "Reserving PCI config space\n"); @@ -299,14 +298,13 @@ static int __init amd_smn_init(void) count = 0; node = 0; - root = NULL; while (node < num_nodes && (root = get_next_root(root))) { /* Use one root for each node and skip the rest. */ if (count++ % roots_per_node) continue; pci_dbg(root, "is root for AMD node %u\n", node); - amd_roots[node++] = root; + amd_roots[node++] = pci_dev_get(root); } if (enable_dfs) { |