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, 50 insertions, 0 deletions

diff --git a/fs/hfs/sysdep.c b/fs/hfs/sysdep.c
new file mode 100644
index 000000000..ef54fc809
--- /dev/null
+++ b/fs/hfs/sysdep.c
@@ -0,0 +1,50 @@
+/*
+ *  linux/fs/hfs/sysdep.c
+ *
+ * Copyright (C) 1996  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ *
+ * This file contains the code to do various system dependent things.
+ */
+
+#include <linux/namei.h>
+#include "hfs_fs.h"
+
+/* dentry case-handling: just lowercase everything */
+
+static int hfs_revalidate_dentry(struct inode *dir, const struct qstr *name,
+				 struct dentry *dentry, unsigned int flags)
+{
+	struct inode *inode;
+	int diff;
+
+	if (flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	inode = d_inode(dentry);
+	if(!inode)
+		return 1;
+
+	/* fix up inode on a timezone change */
+	diff = sys_tz.tz_minuteswest * 60 - HFS_I(inode)->tz_secondswest;
+	if (diff) {
+		struct timespec64 ts = inode_get_ctime(inode);
+
+		inode_set_ctime(inode, ts.tv_sec + diff, ts.tv_nsec);
+		ts = inode_get_atime(inode);
+		inode_set_atime(inode, ts.tv_sec + diff, ts.tv_nsec);
+		ts = inode_get_mtime(inode);
+		inode_set_mtime(inode, ts.tv_sec + diff, ts.tv_nsec);
+		HFS_I(inode)->tz_secondswest += diff;
+	}
+	return 1;
+}
+
+const struct dentry_operations hfs_dentry_operations =
+{
+	.d_revalidate	= hfs_revalidate_dentry,
+	.d_hash		= hfs_hash_dentry,
+	.d_compare	= hfs_compare_dentry,
+};
+