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, 32 insertions, 0 deletions

diff --git a/scripts/depmod.sh b/scripts/depmod.sh
new file mode 100755
index 000000000..3c34fecac
--- /dev/null
+++ b/scripts/depmod.sh
@@ -0,0 +1,32 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# A depmod wrapper
+
+if test $# -ne 1; then
+	echo "Usage: $0 <kernelrelease>" >&2
+	exit 1
+fi
+
+KERNELRELEASE=$1
+
+: ${DEPMOD:=depmod}
+
+if ! test -r "${objtree}/System.map" ; then
+	echo "Warning: modules_install: missing 'System.map' file. Skipping depmod." >&2
+	exit 0
+fi
+
+# legacy behavior: "depmod" in /sbin, no /sbin in PATH
+PATH="$PATH:/sbin"
+if [ -z $(command -v $DEPMOD) ]; then
+	echo "Warning: 'make modules_install' requires $DEPMOD. Please install it." >&2
+	echo "This is probably in the kmod package." >&2
+	exit 0
+fi
+
+set -- -ae -F "${objtree}/System.map"
+if test -n "$INSTALL_MOD_PATH"; then
+	set -- "$@" -b "$INSTALL_MOD_PATH"
+fi
+exec "$DEPMOD" "$@" "$KERNELRELEASE"