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, 156 insertions, 0 deletions

diff --git a/include/trace/events/hugetlbfs.h b/include/trace/events/hugetlbfs.h
new file mode 100644
index 000000000..8ba72c1d4
--- /dev/null
+++ b/include/trace/events/hugetlbfs.h
@@ -0,0 +1,156 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM hugetlbfs
+
+#if !defined(_TRACE_HUGETLBFS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HUGETLBFS_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(hugetlbfs_alloc_inode,
+
+	TP_PROTO(struct inode *inode, struct inode *dir, int mode),
+
+	TP_ARGS(inode, dir, mode),
+
+	TP_STRUCT__entry(
+		__field(u64,		ino)
+		__field(u64,		dir)
+		__field(dev_t,		dev)
+		__field(__u16,		mode)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= inode->i_sb->s_dev;
+		__entry->ino		= inode->i_ino;
+		__entry->dir		= dir ? dir->i_ino : 0;
+		__entry->mode		= mode;
+	),
+
+	TP_printk("dev %d,%d ino %llu dir %llu mode 0%o",
+		MAJOR(__entry->dev), MINOR(__entry->dev),
+		__entry->ino,
+		__entry->dir, __entry->mode)
+);
+
+DECLARE_EVENT_CLASS(hugetlbfs__inode,
+
+	TP_PROTO(struct inode *inode),
+
+	TP_ARGS(inode),
+
+	TP_STRUCT__entry(
+		__field(u64,		ino)
+		__field(loff_t,		size)
+		__field(blkcnt_t,	blocks)
+		__field(dev_t,		dev)
+		__field(unsigned int,	nlink)
+		__field(unsigned int,	seals)
+		__field(__u16,		mode)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= inode->i_sb->s_dev;
+		__entry->ino		= inode->i_ino;
+		__entry->mode		= inode->i_mode;
+		__entry->size		= inode->i_size;
+		__entry->nlink		= inode->i_nlink;
+		__entry->seals		= HUGETLBFS_I(inode)->seals;
+		__entry->blocks		= inode->i_blocks;
+	),
+
+	TP_printk("dev %d,%d ino %llu mode 0%o size %lld nlink %u seals %u blocks %llu",
+		MAJOR(__entry->dev), MINOR(__entry->dev), __entry->ino,
+		__entry->mode, __entry->size, __entry->nlink, __entry->seals,
+		(unsigned long long)__entry->blocks)
+);
+
+DEFINE_EVENT(hugetlbfs__inode, hugetlbfs_evict_inode,
+
+	TP_PROTO(struct inode *inode),
+
+	TP_ARGS(inode)
+);
+
+DEFINE_EVENT(hugetlbfs__inode, hugetlbfs_free_inode,
+
+	TP_PROTO(struct inode *inode),
+
+	TP_ARGS(inode)
+);
+
+TRACE_EVENT(hugetlbfs_setattr,
+
+	TP_PROTO(struct inode *inode, struct dentry *dentry,
+		struct iattr *attr),
+
+	TP_ARGS(inode, dentry, attr),
+
+	TP_STRUCT__entry(
+		__field(u64,		ino)
+		__field(loff_t,		old_size)
+		__field(loff_t,		ia_size)
+		__field(dev_t,		dev)
+		__field(unsigned int,	d_len)
+		__string(d_name,	dentry->d_name.name)
+		__field(unsigned int,	ia_valid)
+		__field(unsigned int,	ia_mode)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= inode->i_sb->s_dev;
+		__entry->ino		= inode->i_ino;
+		__entry->d_len		= dentry->d_name.len;
+		__assign_str(d_name);
+		__entry->ia_valid	= attr->ia_valid;
+		__entry->ia_mode	= attr->ia_mode;
+		__entry->old_size	= inode->i_size;
+		__entry->ia_size	= attr->ia_size;
+	),
+
+	TP_printk("dev %d,%d ino %llu name %.*s valid %#x mode 0%o old_size %lld size %lld",
+		MAJOR(__entry->dev), MINOR(__entry->dev), __entry->ino,
+		__entry->d_len, __get_str(d_name), __entry->ia_valid, __entry->ia_mode,
+		__entry->old_size, __entry->ia_size)
+);
+
+TRACE_EVENT(hugetlbfs_fallocate,
+
+	TP_PROTO(struct inode *inode, int mode,
+		loff_t offset, loff_t len, int ret),
+
+	TP_ARGS(inode, mode, offset, len, ret),
+
+	TP_STRUCT__entry(
+		__field(u64,		ino)
+		__field(loff_t,		offset)
+		__field(loff_t,		len)
+		__field(loff_t,		size)
+		__field(dev_t,		dev)
+		__field(int,		mode)
+		__field(int,		ret)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= inode->i_sb->s_dev;
+		__entry->ino		= inode->i_ino;
+		__entry->mode		= mode;
+		__entry->offset		= offset;
+		__entry->len		= len;
+		__entry->size		= inode->i_size;
+		__entry->ret		= ret;
+	),
+
+	TP_printk("dev %d,%d ino %llu mode 0%o offset %lld len %lld size %lld ret %d",
+		MAJOR(__entry->dev), MINOR(__entry->dev),
+		__entry->ino, __entry->mode,
+		(unsigned long long)__entry->offset,
+		(unsigned long long)__entry->len,
+		(unsigned long long)__entry->size,
+		__entry->ret)
+);
+
+#endif /* _TRACE_HUGETLBFS_H */
+
+ /* This part must be outside protection */
+#include <trace/define_trace.h>