x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

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

1 files changed, 61 insertions, 0 deletions

diff --git a/fs/adfs/dir_f.h b/fs/adfs/dir_f.h
new file mode 100644
index 000000000..4e6c53d59
--- /dev/null
+++ b/fs/adfs/dir_f.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ *  linux/fs/adfs/dir_f.h
+ *
+ *  Copyright (C) 1999 Russell King
+ *
+ *  Structures of directories on the F format disk
+ */
+#ifndef ADFS_DIR_F_H
+#define ADFS_DIR_F_H
+
+/*
+ * Directory header
+ */
+struct adfs_dirheader {
+	__u8 startmasseq;
+	__u8 startname[4];
+} __attribute__((packed));
+
+#define ADFS_NEWDIR_SIZE	2048
+#define ADFS_NUM_DIR_ENTRIES	77
+
+/*
+ * Directory entries
+ */
+struct adfs_direntry {
+#define ADFS_F_NAME_LEN 10
+	char dirobname[ADFS_F_NAME_LEN];
+	__u8 dirload[4];
+	__u8 direxec[4];
+	__u8 dirlen[4];
+	__u8 dirinddiscadd[3];
+	__u8 newdiratts;
+} __attribute__((packed));
+
+/*
+ * Directory tail
+ */
+struct adfs_olddirtail {
+	__u8 dirlastmask;
+	char dirname[10];
+	__u8 dirparent[3];
+	char dirtitle[19];
+	__u8 reserved[14];
+	__u8 endmasseq;
+	__u8 endname[4];
+	__u8 dircheckbyte;
+} __attribute__((packed));
+
+struct adfs_newdirtail {
+	__u8 dirlastmask;
+	__u8 reserved[2];
+	__u8 dirparent[3];
+	char dirtitle[19];
+	char dirname[10];
+	__u8 endmasseq;
+	__u8 endname[4];
+	__u8 dircheckbyte;
+} __attribute__((packed));
+
+#endif