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, 125 insertions, 0 deletions

diff --git a/lib/tests/glob_kunit.c b/lib/tests/glob_kunit.c
new file mode 100644
index 000000000..362b1eda8
--- /dev/null
+++ b/lib/tests/glob_kunit.c
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: MIT OR GPL-2.0
+/*
+ * Test cases for glob functions.
+ */
+
+#include <kunit/test.h>
+#include <linux/glob.h>
+#include <linux/module.h>
+
+/**
+ * struct glob_test_case - Test case for glob matching.
+ * @pat: Pattern to match.
+ * @str: String to match against.
+ * @expected: Expected glob_match result, true if matched.
+ */
+struct glob_test_case {
+	const char *pat;
+	const char *str;
+	bool expected;
+};
+
+static const struct glob_test_case glob_test_cases[] = {
+	/* Some basic tests */
+	{ .pat = "a", .str = "a", .expected = true },
+	{ .pat = "a", .str = "b", .expected = false },
+	{ .pat = "a", .str = "aa", .expected = false },
+	{ .pat = "a", .str = "", .expected = false },
+	{ .pat = "", .str = "", .expected = true },
+	{ .pat = "", .str = "a", .expected = false },
+	/* Simple character class tests */
+	{ .pat = "[a]", .str = "a", .expected = true },
+	{ .pat = "[a]", .str = "b", .expected = false },
+	{ .pat = "[!a]", .str = "a", .expected = false },
+	{ .pat = "[!a]", .str = "b", .expected = true },
+	{ .pat = "[ab]", .str = "a", .expected = true },
+	{ .pat = "[ab]", .str = "b", .expected = true },
+	{ .pat = "[ab]", .str = "c", .expected = false },
+	{ .pat = "[!ab]", .str = "c", .expected = true },
+	{ .pat = "[a-c]", .str = "b", .expected = true },
+	{ .pat = "[a-c]", .str = "d", .expected = false },
+	/* Corner cases in character class parsing */
+	{ .pat = "[a-c-e-g]", .str = "-", .expected = true },
+	{ .pat = "[a-c-e-g]", .str = "d", .expected = false },
+	{ .pat = "[a-c-e-g]", .str = "f", .expected = true },
+	{ .pat = "[]a-ceg-ik[]", .str = "a", .expected = true },
+	{ .pat = "[]a-ceg-ik[]", .str = "]", .expected = true },
+	{ .pat = "[]a-ceg-ik[]", .str = "[", .expected = true },
+	{ .pat = "[]a-ceg-ik[]", .str = "h", .expected = true },
+	{ .pat = "[]a-ceg-ik[]", .str = "f", .expected = false },
+	{ .pat = "[!]a-ceg-ik[]", .str = "h", .expected = false },
+	{ .pat = "[!]a-ceg-ik[]", .str = "]", .expected = false },
+	{ .pat = "[!]a-ceg-ik[]", .str = "f", .expected = true },
+	/* Simple wild cards */
+	{ .pat = "?", .str = "a", .expected = true },
+	{ .pat = "?", .str = "aa", .expected = false },
+	{ .pat = "??", .str = "a", .expected = false },
+	{ .pat = "?x?", .str = "axb", .expected = true },
+	{ .pat = "?x?", .str = "abx", .expected = false },
+	{ .pat = "?x?", .str = "xab", .expected = false },
+	/* Asterisk wild cards (backtracking) */
+	{ .pat = "*??", .str = "a", .expected = false },
+	{ .pat = "*??", .str = "ab", .expected = true },
+	{ .pat = "*??", .str = "abc", .expected = true },
+	{ .pat = "*??", .str = "abcd", .expected = true },
+	{ .pat = "??*", .str = "a", .expected = false },
+	{ .pat = "??*", .str = "ab", .expected = true },
+	{ .pat = "??*", .str = "abc", .expected = true },
+	{ .pat = "??*", .str = "abcd", .expected = true },
+	{ .pat = "?*?", .str = "a", .expected = false },
+	{ .pat = "?*?", .str = "ab", .expected = true },
+	{ .pat = "?*?", .str = "abc", .expected = true },
+	{ .pat = "?*?", .str = "abcd", .expected = true },
+	{ .pat = "*b", .str = "b", .expected = true },
+	{ .pat = "*b", .str = "ab", .expected = true },
+	{ .pat = "*b", .str = "ba", .expected = false },
+	{ .pat = "*b", .str = "bb", .expected = true },
+	{ .pat = "*b", .str = "abb", .expected = true },
+	{ .pat = "*b", .str = "bab", .expected = true },
+	{ .pat = "*bc", .str = "abbc", .expected = true },
+	{ .pat = "*bc", .str = "bc", .expected = true },
+	{ .pat = "*bc", .str = "bbc", .expected = true },
+	{ .pat = "*bc", .str = "bcbc", .expected = true },
+	/* Multiple asterisks (complex backtracking) */
+	{ .pat = "*ac*", .str = "abacadaeafag", .expected = true },
+	{ .pat = "*ac*ae*ag*", .str = "abacadaeafag", .expected = true },
+	{ .pat = "*a*b*[bc]*[ef]*g*", .str = "abacadaeafag", .expected = true },
+	{ .pat = "*a*b*[ef]*[cd]*g*", .str = "abacadaeafag", .expected = false },
+	{ .pat = "*abcd*", .str = "abcabcabcabcdefg", .expected = true },
+	{ .pat = "*ab*cd*", .str = "abcabcabcabcdefg", .expected = true },
+	{ .pat = "*abcd*abcdef*", .str = "abcabcdabcdeabcdefg", .expected = true },
+	{ .pat = "*abcd*", .str = "abcabcabcabcefg", .expected = false },
+	{ .pat = "*ab*cd*", .str = "abcabcabcabcefg", .expected = false },
+};
+
+static void glob_case_to_desc(const struct glob_test_case *t, char *desc)
+{
+	snprintf(desc, KUNIT_PARAM_DESC_SIZE, "pat:\"%s\" str:\"%s\"", t->pat, t->str);
+}
+
+KUNIT_ARRAY_PARAM(glob, glob_test_cases, glob_case_to_desc);
+
+static void glob_test_match(struct kunit *test)
+{
+	const struct glob_test_case *params = test->param_value;
+
+	KUNIT_EXPECT_EQ_MSG(test,
+			    glob_match(params->pat, params->str),
+			    params->expected,
+			    "Pattern: \"%s\", String: \"%s\", Expected: %d",
+			    params->pat, params->str, params->expected);
+}
+
+static struct kunit_case glob_kunit_test_cases[] = {
+	KUNIT_CASE_PARAM(glob_test_match, glob_gen_params),
+	{}
+};
+
+static struct kunit_suite glob_test_suite = {
+	.name = "glob",
+	.test_cases = glob_kunit_test_cases,
+};
+
+kunit_test_suite(glob_test_suite);
+MODULE_DESCRIPTION("Test cases for glob functions");
+MODULE_LICENSE("Dual MIT/GPL");