Merge tag 'linux_kselftest-kunit-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kunit updates from Shuah Khan:
 "kunit tool:
   - Changes to kunit tool to use qboot on QEMU x86_64, and build GDB
     scripts
   - Fixes kunit tool bug in parsing test plan
   - Adds test to kunit tool to check parsing late test plan

  kunit:
   - Clarifies kunit_skip() argument name
   - Adds Kunit check for the longest symbol length
   - Changes qemu_configs for sparc to use Zilog console"

* tag 'linux_kselftest-kunit-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  kunit: tool: add test to check parsing late test plan
  kunit: tool: Fix bug in parsing test plan
  Kunit to check the longest symbol length
  kunit: Clarify kunit_skip() argument name
  kunit: tool: Build GDB scripts
  kunit: qemu_configs: sparc: use Zilog console
  kunit: tool: Use qboot on QEMU x86_64

3 files changed, 95 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 8fb1d685f696..0ffd5526bd46 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2866,6 +2866,15 @@ config FORTIFY_KUNIT_TEST
 	  by the str*() and mem*() family of functions. For testing runtime
 	  traps of FORTIFY_SOURCE, see LKDTM's "FORTIFY_*" tests.
 
+config LONGEST_SYM_KUNIT_TEST
+	tristate "Test the longest symbol possible" if !KUNIT_ALL_TESTS
+	depends on KUNIT && KPROBES
+	default KUNIT_ALL_TESTS
+	help
+	  Tests the longest symbol possible
+
+	  If unsure, say N.
+
 config HW_BREAKPOINT_KUNIT_TEST
 	bool "Test hw_breakpoint constraints accounting" if !KUNIT_ALL_TESTS
 	depends on HAVE_HW_BREAKPOINT
diff --git a/lib/tests/Makefile b/lib/tests/Makefile
index a434c7cb733a..5a4794c1826e 100644
--- a/lib/tests/Makefile
+++ b/lib/tests/Makefile
@@ -27,6 +27,10 @@ obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o
 obj-$(CONFIG_KFIFO_KUNIT_TEST) += kfifo_kunit.o
 obj-$(CONFIG_TEST_LIST_SORT) += test_list_sort.o
 obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o
+
+CFLAGS_longest_symbol_kunit.o += $(call cc-disable-warning, missing-prototypes)
+obj-$(CONFIG_LONGEST_SYM_KUNIT_TEST) += longest_symbol_kunit.o
+
 obj-$(CONFIG_MEMCPY_KUNIT_TEST) += memcpy_kunit.o
 CFLAGS_overflow_kunit.o = $(call cc-disable-warning, tautological-constant-out-of-range-compare)
 obj-$(CONFIG_OVERFLOW_KUNIT_TEST) += overflow_kunit.o
diff --git a/lib/tests/longest_symbol_kunit.c b/lib/tests/longest_symbol_kunit.c
new file mode 100644
index 000000000000..e3c28ff1807f
--- /dev/null
+++ b/lib/tests/longest_symbol_kunit.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test the longest symbol length. Execute with:
+ *  ./tools/testing/kunit/kunit.py run longest-symbol
+ *  --arch=x86_64 --kconfig_add CONFIG_KPROBES=y --kconfig_add CONFIG_MODULES=y
+ *  --kconfig_add CONFIG_RETPOLINE=n --kconfig_add CONFIG_CFI_CLANG=n
+ *  --kconfig_add CONFIG_MITIGATION_RETPOLINE=n
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <kunit/test.h>
+#include <linux/stringify.h>
+#include <linux/kprobes.h>
+#include <linux/kallsyms.h>
+
+#define DI(name) s##name##name
+#define DDI(name) DI(n##name##name)
+#define DDDI(name) DDI(n##name##name)
+#define DDDDI(name) DDDI(n##name##name)
+#define DDDDDI(name) DDDDI(n##name##name)
+
+/*Generate a symbol whose name length is 511 */
+#define LONGEST_SYM_NAME  DDDDDI(g1h2i3j4k5l6m7n)
+
+#define RETURN_LONGEST_SYM 0xAAAAA
+
+noinline int LONGEST_SYM_NAME(void);
+noinline int LONGEST_SYM_NAME(void)
+{
+	return RETURN_LONGEST_SYM;
+}
+
+_Static_assert(sizeof(__stringify(LONGEST_SYM_NAME)) == KSYM_NAME_LEN,
+"Incorrect symbol length found. Expected KSYM_NAME_LEN: "
+__stringify(KSYM_NAME_LEN) ", but found: "
+__stringify(sizeof(LONGEST_SYM_NAME)));
+
+static void test_longest_symbol(struct kunit *test)
+{
+	KUNIT_EXPECT_EQ(test, RETURN_LONGEST_SYM, LONGEST_SYM_NAME());
+};
+
+static void test_longest_symbol_kallsyms(struct kunit *test)
+{
+	unsigned long (*kallsyms_lookup_name)(const char *name);
+	static int (*longest_sym)(void);
+
+	struct kprobe kp = {
+		.symbol_name = "kallsyms_lookup_name",
+	};
+
+	if (register_kprobe(&kp) < 0) {
+		pr_info("%s: kprobe not registered", __func__);
+		KUNIT_FAIL(test, "test_longest_symbol kallsyms: kprobe not registered\n");
+		return;
+	}
+
+	kunit_warn(test, "test_longest_symbol kallsyms: kprobe registered\n");
+	kallsyms_lookup_name = (unsigned long (*)(const char *name))kp.addr;
+	unregister_kprobe(&kp);
+
+	longest_sym =
+		(void *) kallsyms_lookup_name(__stringify(LONGEST_SYM_NAME));
+	KUNIT_EXPECT_EQ(test, RETURN_LONGEST_SYM, longest_sym());
+};
+
+static struct kunit_case longest_symbol_test_cases[] = {
+	KUNIT_CASE(test_longest_symbol),
+	KUNIT_CASE(test_longest_symbol_kallsyms),
+	{}
+};
+
+static struct kunit_suite longest_symbol_test_suite = {
+	.name = "longest-symbol",
+	.test_cases = longest_symbol_test_cases,
+};
+kunit_test_suite(longest_symbol_test_suite);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Test the longest symbol length");
+MODULE_AUTHOR("Sergio González Collado");