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 --- lib/memcat_p.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100644 lib/memcat_p.c (limited to 'lib/memcat_p.c') diff --git a/lib/memcat_p.c b/lib/memcat_p.c new file mode 100644 index 000000000..b810fbc66 --- /dev/null +++ b/lib/memcat_p.c @@ -0,0 +1,34 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +/* + * Merge two NULL-terminated pointer arrays into a newly allocated + * array, which is also NULL-terminated. Nomenclature is inspired by + * memset_p() and memcat() found elsewhere in the kernel source tree. + */ +void **__memcat_p(void **a, void **b) +{ + void **p = a, **new; + int nr; + + /* count the elements in both arrays */ + for (nr = 0, p = a; *p; nr++, p++) + ; + for (p = b; *p; nr++, p++) + ; + /* one for the NULL-terminator */ + nr++; + + new = kmalloc_array(nr, sizeof(void *), GFP_KERNEL); + if (!new) + return NULL; + + /* nr -> last index; p points to NULL in b[] */ + for (nr--; nr >= 0; nr--, p = p == b ? &a[nr] : p - 1) + new[nr] = *p; + + return new; +} +EXPORT_SYMBOL_GPL(__memcat_p); + -- cgit v1.3.1