ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 924 insertions, 0 deletions

diff --git a/lib/test-kstrtox.c b/lib/test-kstrtox.c
new file mode 100644
index 000000000..925523475
--- /dev/null
+++ b/lib/test-kstrtox.c
@@ -0,0 +1,924 @@
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#define for_each_test(i, test)	\
+	for (i = 0; i < ARRAY_SIZE(test); i++)
+
+struct test_fail {
+	const char *str;
+	unsigned int base;
+};
+
+#define DEFINE_TEST_FAIL(test)	\
+	const struct test_fail test[] __initconst
+
+#define DECLARE_TEST_OK(type, test_type)	\
+	test_type {				\
+		const char *str;		\
+		unsigned int base;		\
+		type expected_res;		\
+	}
+
+#define DEFINE_TEST_OK(type, test)	\
+	const type test[] __initconst
+
+#define TEST_FAIL(fn, type, fmt, test)					\
+{									\
+	unsigned int i;							\
+									\
+	for_each_test(i, test) {					\
+		const struct test_fail *t = &test[i];			\
+		type tmp;						\
+		int rv;							\
+									\
+		tmp = 0;						\
+		rv = fn(t->str, t->base, &tmp);				\
+		if (rv >= 0) {						\
+			WARN(1, "str '%s', base %u, expected -E, got %d/" fmt "\n",	\
+				t->str, t->base, rv, tmp);		\
+			continue;					\
+		}							\
+	}								\
+}
+
+#define TEST_OK(fn, type, fmt, test)					\
+{									\
+	unsigned int i;							\
+									\
+	for_each_test(i, test) {					\
+		const typeof(test[0]) *t = &test[i];			\
+		type res;						\
+		int rv;							\
+									\
+		rv = fn(t->str, t->base, &res);				\
+		if (rv != 0) {						\
+			WARN(1, "str '%s', base %u, expected 0/" fmt ", got %d\n",	\
+				t->str, t->base, t->expected_res, rv);	\
+			continue;					\
+		}							\
+		if (res != t->expected_res) {				\
+			WARN(1, "str '%s', base %u, expected " fmt ", got " fmt "\n",	\
+				t->str, t->base, t->expected_res, res);	\
+			continue;					\
+		}							\
+	}								\
+}
+
+static void __init test_kstrtoull_ok(void)
+{
+	DECLARE_TEST_OK(unsigned long long, struct test_ull);
+	static DEFINE_TEST_OK(struct test_ull, test_ull_ok) = {
+		{"0",	10,	0ULL},
+		{"1",	10,	1ULL},
+		{"127",	10,	127ULL},
+		{"128",	10,	128ULL},
+		{"129",	10,	129ULL},
+		{"255",	10,	255ULL},
+		{"256",	10,	256ULL},
+		{"257",	10,	257ULL},
+		{"32767",	10,	32767ULL},
+		{"32768",	10,	32768ULL},
+		{"32769",	10,	32769ULL},
+		{"65535",	10,	65535ULL},
+		{"65536",	10,	65536ULL},
+		{"65537",	10,	65537ULL},
+		{"2147483647",	10,	2147483647ULL},
+		{"2147483648",	10,	2147483648ULL},
+		{"2147483649",	10,	2147483649ULL},
+		{"4294967295",	10,	4294967295ULL},
+		{"4294967296",	10,	4294967296ULL},
+		{"4294967297",	10,	4294967297ULL},
+		{"9223372036854775807",	10,	9223372036854775807ULL},
+		{"9223372036854775808",	10,	9223372036854775808ULL},
+		{"9223372036854775809",	10,	9223372036854775809ULL},
+		{"18446744073709551614",	10,	18446744073709551614ULL},
+		{"18446744073709551615",	10,	18446744073709551615ULL},
+
+		{"00",		8,	00ULL},
+		{"01",		8,	01ULL},
+		{"0177",	8,	0177ULL},
+		{"0200",	8,	0200ULL},
+		{"0201",	8,	0201ULL},
+		{"0377",	8,	0377ULL},
+		{"0400",	8,	0400ULL},
+		{"0401",	8,	0401ULL},
+		{"077777",	8,	077777ULL},
+		{"0100000",	8,	0100000ULL},
+		{"0100001",	8,	0100001ULL},
+		{"0177777",	8,	0177777ULL},
+		{"0200000",	8,	0200000ULL},
+		{"0200001",	8,	0200001ULL},
+		{"017777777777",	8,	017777777777ULL},
+		{"020000000000",	8,	020000000000ULL},
+		{"020000000001",	8,	020000000001ULL},
+		{"037777777777",	8,	037777777777ULL},
+		{"040000000000",	8,	040000000000ULL},
+		{"040000000001",	8,	040000000001ULL},
+		{"0777777777777777777777",	8,	0777777777777777777777ULL},
+		{"01000000000000000000000",	8,	01000000000000000000000ULL},
+		{"01000000000000000000001",	8,	01000000000000000000001ULL},
+		{"01777777777777777777776",	8,	01777777777777777777776ULL},
+		{"01777777777777777777777",	8,	01777777777777777777777ULL},
+
+		{"0x0",		16,	0x0ULL},
+		{"0x1",		16,	0x1ULL},
+		{"0x7f",	16,	0x7fULL},
+		{"0x80",	16,	0x80ULL},
+		{"0x81",	16,	0x81ULL},
+		{"0xff",	16,	0xffULL},
+		{"0x100",	16,	0x100ULL},
+		{"0x101",	16,	0x101ULL},
+		{"0x7fff",	16,	0x7fffULL},
+		{"0x8000",	16,	0x8000ULL},
+		{"0x8001",	16,	0x8001ULL},
+		{"0xffff",	16,	0xffffULL},
+		{"0x10000",	16,	0x10000ULL},
+		{"0x10001",	16,	0x10001ULL},
+		{"0x7fffffff",	16,	0x7fffffffULL},
+		{"0x80000000",	16,	0x80000000ULL},
+		{"0x80000001",	16,	0x80000001ULL},
+		{"0xffffffff",	16,	0xffffffffULL},
+		{"0x100000000",	16,	0x100000000ULL},
+		{"0x100000001",	16,	0x100000001ULL},
+		{"0x7fffffffffffffff",	16,	0x7fffffffffffffffULL},
+		{"0x8000000000000000",	16,	0x8000000000000000ULL},
+		{"0x8000000000000001",	16,	0x8000000000000001ULL},
+		{"0xfffffffffffffffe",	16,	0xfffffffffffffffeULL},
+		{"0xffffffffffffffff",	16,	0xffffffffffffffffULL},
+
+		{"0\n",	0,	0ULL},
+	};
+	TEST_OK(kstrtoull, unsigned long long, "%llu", test_ull_ok);
+}
+
+static void __init test_kstrtoull_fail(void)
+{
+	static DEFINE_TEST_FAIL(test_ull_fail) = {
+		{"",	0},
+		{"",	8},
+		{"",	10},
+		{"",	16},
+		{"\n",	0},
+		{"\n",	8},
+		{"\n",	10},
+		{"\n",	16},
+		{"\n0",	0},
+		{"\n0",	8},
+		{"\n0",	10},
+		{"\n0",	16},
+		{"+",	0},
+		{"+",	8},
+		{"+",	10},
+		{"+",	16},
+		{"-",	0},
+		{"-",	8},
+		{"-",	10},
+		{"-",	16},
+		{"0x",	0},
+		{"0x",	16},
+		{"0X",	0},
+		{"0X",	16},
+		{"0 ",	0},
+		{"1+",	0},
+		{"1-",	0},
+		{" 2",	0},
+		/* base autodetection */
+		{"0x0z",	0},
+		{"0z",		0},
+		{"a",		0},
+		/* digit >= base */
+		{"2",	2},
+		{"8",	8},
+		{"a",	10},
+		{"A",	10},
+		{"g",	16},
+		{"G",	16},
+		/* overflow */
+		{"10000000000000000000000000000000000000000000000000000000000000000",	2},
+		{"2000000000000000000000",	8},
+		{"18446744073709551616",	10},
+		{"569202370375329612767",	10},
+		{"10000000000000000",	16},
+		/* negative */
+		{"-0", 0},
+		{"-0", 8},
+		{"-0", 10},
+		{"-0", 16},
+		{"-1", 0},
+		{"-1", 8},
+		{"-1", 10},
+		{"-1", 16},
+		/* sign is first character if any */
+		{"-+1", 0},
+		{"-+1", 8},
+		{"-+1", 10},
+		{"-+1", 16},
+		/* nothing after \n */
+		{"0\n0", 0},
+		{"0\n0", 8},
+		{"0\n0", 10},
+		{"0\n0", 16},
+		{"0\n+", 0},
+		{"0\n+", 8},
+		{"0\n+", 10},
+		{"0\n+", 16},
+		{"0\n-", 0},
+		{"0\n-", 8},
+		{"0\n-", 10},
+		{"0\n-", 16},
+		{"0\n ", 0},
+		{"0\n ", 8},
+		{"0\n ", 10},
+		{"0\n ", 16},
+	};
+	TEST_FAIL(kstrtoull, unsigned long long, "%llu", test_ull_fail);
+}
+
+static void __init test_kstrtoll_ok(void)
+{
+	DECLARE_TEST_OK(long long, struct test_ll);
+	static DEFINE_TEST_OK(struct test_ll, test_ll_ok) = {
+		{"0",	10,	0LL},
+		{"1",	10,	1LL},
+		{"127",	10,	127LL},
+		{"128",	10,	128LL},
+		{"129",	10,	129LL},
+		{"255",	10,	255LL},
+		{"256",	10,	256LL},
+		{"257",	10,	257LL},
+		{"32767",	10,	32767LL},
+		{"32768",	10,	32768LL},
+		{"32769",	10,	32769LL},
+		{"65535",	10,	65535LL},
+		{"65536",	10,	65536LL},
+		{"65537",	10,	65537LL},
+		{"2147483647",	10,	2147483647LL},
+		{"2147483648",	10,	2147483648LL},
+		{"2147483649",	10,	2147483649LL},
+		{"4294967295",	10,	4294967295LL},
+		{"4294967296",	10,	4294967296LL},
+		{"4294967297",	10,	4294967297LL},
+		{"9223372036854775807",	10,	9223372036854775807LL},
+
+		{"-0",	10,	0LL},
+		{"-1",	10,	-1LL},
+		{"-2",	10,	-2LL},
+		{"-9223372036854775808",	10,	LLONG_MIN},
+	};
+	TEST_OK(kstrtoll, long long, "%lld", test_ll_ok);
+}
+
+static void __init test_kstrtoll_fail(void)
+{
+	static DEFINE_TEST_FAIL(test_ll_fail) = {
+		{"9223372036854775808",	10},
+		{"9223372036854775809",	10},
+		{"18446744073709551614",	10},
+		{"18446744073709551615",	10},
+		{"569202370375329612767",	10},
+		{"-9223372036854775809",	10},
+		{"-18446744073709551614",	10},
+		{"-18446744073709551615",	10},
+		{"-569202370375329612767",	10},
+		/* sign is first character if any */
+		{"-+1", 0},
+		{"-+1", 8},
+		{"-+1", 10},
+		{"-+1", 16},
+	};
+	TEST_FAIL(kstrtoll, long long, "%lld", test_ll_fail);
+}
+
+static void __init test_kstrtou64_ok(void)
+{
+	DECLARE_TEST_OK(u64, struct test_u64);
+	static DEFINE_TEST_OK(struct test_u64, test_u64_ok) = {
+		{"0",	10,	0},
+		{"1",	10,	1},
+		{"126",	10,	126},
+		{"127",	10,	127},
+		{"128",	10,	128},
+		{"129",	10,	129},
+		{"254",	10,	254},
+		{"255",	10,	255},
+		{"256",	10,	256},
+		{"257",	10,	257},
+		{"32766",	10,	32766},
+		{"32767",	10,	32767},
+		{"32768",	10,	32768},
+		{"32769",	10,	32769},
+		{"65534",	10,	65534},
+		{"65535",	10,	65535},
+		{"65536",	10,	65536},
+		{"65537",	10,	65537},
+		{"2147483646",	10,	2147483646},
+		{"2147483647",	10,	2147483647},
+		{"2147483648",	10,	2147483648ULL},
+		{"2147483649",	10,	2147483649ULL},
+		{"4294967294",	10,	4294967294ULL},
+		{"4294967295",	10,	4294967295ULL},
+		{"4294967296",	10,	4294967296ULL},
+		{"4294967297",	10,	4294967297ULL},
+		{"9223372036854775806",	10,	9223372036854775806ULL},
+		{"9223372036854775807",	10,	9223372036854775807ULL},
+		{"9223372036854775808",	10,	9223372036854775808ULL},
+		{"9223372036854775809",	10,	9223372036854775809ULL},
+		{"18446744073709551614",	10,	18446744073709551614ULL},
+		{"18446744073709551615",	10,	18446744073709551615ULL},
+	};
+	TEST_OK(kstrtou64, u64, "%llu", test_u64_ok);
+}
+
+static void __init test_kstrtou64_fail(void)
+{
+	static DEFINE_TEST_FAIL(test_u64_fail) = {
+		{"-2",	10},
+		{"-1",	10},
+		{"18446744073709551616",	10},
+		{"18446744073709551617",	10},
+		{"569202370375329612767",	10},
+	};
+	TEST_FAIL(kstrtou64, u64, "%llu", test_u64_fail);
+}
+
+static void __init test_kstrtos64_ok(void)
+{
+	DECLARE_TEST_OK(s64, struct test_s64);
+	static DEFINE_TEST_OK(struct test_s64, test_s64_ok) = {
+		{"-128",	10,	-128},
+		{"-127",	10,	-127},
+		{"-1",	10,	-1},
+		{"0",	10,	0},
+		{"1",	10,	1},
+		{"126",	10,	126},
+		{"127",	10,	127},
+		{"128",	10,	128},
+		{"129",	10,	129},
+		{"254",	10,	254},
+		{"255",	10,	255},
+		{"256",	10,	256},
+		{"257",	10,	257},
+		{"32766",	10,	32766},
+		{"32767",	10,	32767},
+		{"32768",	10,	32768},
+		{"32769",	10,	32769},
+		{"65534",	10,	65534},
+		{"65535",	10,	65535},
+		{"65536",	10,	65536},
+		{"65537",	10,	65537},
+		{"2147483646",	10,	2147483646},
+		{"2147483647",	10,	2147483647},
+		{"2147483648",	10,	2147483648LL},
+		{"2147483649",	10,	2147483649LL},
+		{"4294967294",	10,	4294967294LL},
+		{"4294967295",	10,	4294967295LL},
+		{"4294967296",	10,	4294967296LL},
+		{"4294967297",	10,	4294967297LL},
+		{"9223372036854775806",	10,	9223372036854775806LL},
+		{"9223372036854775807",	10,	9223372036854775807LL},
+	};
+	TEST_OK(kstrtos64, s64, "%lld", test_s64_ok);
+}
+
+static void __init test_kstrtos64_fail(void)
+{
+	static DEFINE_TEST_FAIL(test_s64_fail) = {
+		{"9223372036854775808",	10},
+		{"9223372036854775809",	10},
+		{"18446744073709551614",	10},
+		{"18446744073709551615",	10},
+		{"18446744073709551616",	10},
+		{"18446744073709551617",	10},
+		{"569202370375329612767",	10},
+		{"-569202370375329612767",	10},
+	};
+	TEST_FAIL(kstrtos64, s64, "%lld", test_s64_fail);
+}
+
+static void __init test_kstrtou32_ok(void)
+{
+	DECLARE_TEST_OK(u32, struct test_u32);
+	static DEFINE_TEST_OK(struct test_u32, test_u32_ok) = {
+		{"0",	10,	0},
+		{"1",	10,	1},
+		{"126",	10,	126},
+		{"127",	10,	127},
+		{"128",	10,	128},
+		{"129",	10,	129},
+		{"254",	10,	254},
+		{"255",	10,	255},
+		{"256",	10,	256},
+		{"257",	10,	257},
+		{"32766",	10,	32766},
+		{"32767",	10,	32767},
+		{"32768",	10,	32768},
+		{"32769",	10,	32769},
+		{"65534",	10,	65534},
+		{"65535",	10,	65535},
+		{"65536",	10,	65536},
+		{"65537",	10,	65537},
+		{"2147483646",	10,	2147483646},
+		{"2147483647",	10,	2147483647},
+		{"2147483648",	10,	2147483648U},
+		{"2147483649",	10,	2147483649U},
+		{"4294967294",	10,	4294967294U},
+		{"4294967295",	10,	4294967295U},
+	};
+	TEST_OK(kstrtou32, u32, "%u", test_u32_ok);
+}
+
+static void __init test_kstrtou32_fail(void)
+{
+	static DEFINE_TEST_FAIL(test_u32_fail) = {
+		{"-2",	10},
+		{"-1",	10},
+		{"4294967296",	10},
+		{"4294967297",	10},
+		{"9223372036854775806",	10},
+		{"9223372036854775807",	10},
+		{"9223372036854775808",	10},
+		{"9223372036854775809",	10},
+		{"18446744073709551614",	10},
+		{"18446744073709551615",	10},
+		{"18446744073709551616",	10},
+		{"18446744073709551617",	10},
+	};
+	TEST_FAIL(kstrtou32, u32, "%u", test_u32_fail);
+}
+
+static void __init test_kstrtos32_ok(void)
+{
+	DECLARE_TEST_OK(s32, struct test_s32);
+	static DEFINE_TEST_OK(struct test_s32, test_s32_ok) = {
+		{"-128",	10,	-128},
+		{"-127",	10,	-127},
+		{"-1",	10,	-1},
+		{"0",	10,	0},
+		{"1",	10,	1},
+		{"126",	10,	126},
+		{"127",	10,	127},
+		{"128",	10,	128},
+		{"129",	10,	129},
+		{"254",	10,	254},
+		{"255",	10,	255},
+		{"256",	10,	256},
+		{"257",	10,	257},
+		{"32766",	10,	32766},
+		{"32767",	10,	32767},
+		{"32768",	10,	32768},
+		{"32769",	10,	32769},
+		{"65534",	10,	65534},
+		{"65535",	10,	65535},
+		{"65536",	10,	65536},
+		{"65537",	10,	65537},
+		{"2147483646",	10,	2147483646},
+		{"2147483647",	10,	2147483647},
+	};
+	TEST_OK(kstrtos32, s32, "%d", test_s32_ok);
+}
+
+static void __init test_kstrtos32_fail(void)
+{
+	static DEFINE_TEST_FAIL(test_s32_fail) = {
+		{"2147483648",	10},
+		{"2147483649",	10},
+		{"4294967294",	10},
+		{"4294967295",	10},
+		{"4294967296",	10},
+		{"4294967297",	10},
+		{"9223372036854775806",	10},
+		{"9223372036854775807",	10},
+		{"9223372036854775808",	10},
+		{"9223372036854775809",	10},
+		{"18446744073709551614",	10},
+		{"18446744073709551615",	10},
+		{"18446744073709551616",	10},
+		{"18446744073709551617",	10},
+	};
+	TEST_FAIL(kstrtos32, s32, "%d", test_s32_fail);
+}
+
+static void __init test_kstrtou16_ok(void)
+{
+	DECLARE_TEST_OK(u16, struct test_u16);
+	static DEFINE_TEST_OK(struct test_u16, test_u16_ok) = {
+		{"0",	10,	0},
+		{"1",	10,	1},
+		{"126",	10,	126},
+		{"127",	10,	127},
+		{"128",	10,	128},
+		{"129",	10,	129},
+		{"254",	10,	254},
+		{"255",	10,	255},
+		{"256",	10,	256},
+		{"257",	10,	257},
+		{"32766",	10,	32766},
+		{"32767",	10,	32767},
+		{"32768",	10,	32768},
+		{"32769",	10,	32769},
+		{"65534",	10,	65534},
+		{"65535",	10,	65535},
+	};
+	TEST_OK(kstrtou16, u16, "%hu", test_u16_ok);
+}
+
+static void __init test_kstrtou16_fail(void)
+{
+	static DEFINE_TEST_FAIL(test_u16_fail) = {
+		{"-2",	10},
+		{"-1",	10},
+		{"65536",	10},
+		{"65537",	10},
+		{"2147483646",	10},
+		{"2147483647",	10},
+		{"2147483648",	10},
+		{"2147483649",	10},
+		{"4294967294",	10},
+		{"4294967295",	10},
+		{"4294967296",	10},
+		{"4294967297",	10},
+		{"9223372036854775806",	10},
+		{"9223372036854775807",	10},
+		{"9223372036854775808",	10},
+		{"9223372036854775809",	10},
+		{"18446744073709551614",	10},
+		{"18446744073709551615",	10},
+		{"18446744073709551616",	10},
+		{"18446744073709551617",	10},
+	};
+	TEST_FAIL(kstrtou16, u16, "%hu", test_u16_fail);
+}
+
+static void __init test_kstrtos16_ok(void)
+{
+	DECLARE_TEST_OK(s16, struct test_s16);
+	static DEFINE_TEST_OK(struct test_s16, test_s16_ok) = {
+		{"-130",	10,	-130},
+		{"-129",	10,	-129},
+		{"-128",	10,	-128},
+		{"-127",	10,	-127},
+		{"-1",	10,	-1},
+		{"0",	10,	0},
+		{"1",	10,	1},
+		{"126",	10,	126},
+		{"127",	10,	127},
+		{"128",	10,	128},
+		{"129",	10,	129},
+		{"254",	10,	254},
+		{"255",	10,	255},
+		{"256",	10,	256},
+		{"257",	10,	257},
+		{"32766",	10,	32766},
+		{"32767",	10,	32767},
+	};
+	TEST_OK(kstrtos16, s16, "%hd", test_s16_ok);
+}
+
+static void __init test_kstrtos16_fail(void)
+{
+	static DEFINE_TEST_FAIL(test_s16_fail) = {
+		{"32768",	10},
+		{"32769",	10},
+		{"65534",	10},
+		{"65535",	10},
+		{"65536",	10},
+		{"65537",	10},
+		{"2147483646",	10},
+		{"2147483647",	10},
+		{"2147483648",	10},
+		{"2147483649",	10},
+		{"4294967294",	10},
+		{"4294967295",	10},
+		{"4294967296",	10},
+		{"4294967297",	10},
+		{"9223372036854775806",	10},
+		{"9223372036854775807",	10},
+		{"9223372036854775808",	10},
+		{"9223372036854775809",	10},
+		{"18446744073709551614",	10},
+		{"18446744073709551615",	10},
+		{"18446744073709551616",	10},
+		{"18446744073709551617",	10},
+	};
+	TEST_FAIL(kstrtos16, s16, "%hd", test_s16_fail);
+}
+
+static void __init test_kstrtou8_ok(void)
+{
+	DECLARE_TEST_OK(u8, struct test_u8);
+	static DEFINE_TEST_OK(struct test_u8, test_u8_ok) = {
+		{"0",	10,	0},
+		{"1",	10,	1},
+		{"126",	10,	126},
+		{"127",	10,	127},
+		{"128",	10,	128},
+		{"129",	10,	129},
+		{"254",	10,	254},
+		{"255",	10,	255},
+	};
+	TEST_OK(kstrtou8, u8, "%hhu", test_u8_ok);
+}
+
+static void __init test_kstrtou8_fail(void)
+{
+	static DEFINE_TEST_FAIL(test_u8_fail) = {
+		{"-2",	10},
+		{"-1",	10},
+		{"256",	10},
+		{"257",	10},
+		{"32766",	10},
+		{"32767",	10},
+		{"32768",	10},
+		{"32769",	10},
+		{"65534",	10},
+		{"65535",	10},
+		{"65536",	10},
+		{"65537",	10},
+		{"2147483646",	10},
+		{"2147483647",	10},
+		{"2147483648",	10},
+		{"2147483649",	10},
+		{"4294967294",	10},
+		{"4294967295",	10},
+		{"4294967296",	10},
+		{"4294967297",	10},
+		{"9223372036854775806",	10},
+		{"9223372036854775807",	10},
+		{"9223372036854775808",	10},
+		{"9223372036854775809",	10},
+		{"18446744073709551614",	10},
+		{"18446744073709551615",	10},
+		{"18446744073709551616",	10},
+		{"18446744073709551617",	10},
+	};
+	TEST_FAIL(kstrtou8, u8, "%hhu", test_u8_fail);
+}
+
+static void __init test_kstrtos8_ok(void)
+{
+	DECLARE_TEST_OK(s8, struct test_s8);
+	static DEFINE_TEST_OK(struct test_s8, test_s8_ok) = {
+		{"-128",	10,	-128},
+		{"-127",	10,	-127},
+		{"-1",	10,	-1},
+		{"0",	10,	0},
+		{"1",	10,	1},
+		{"126",	10,	126},
+		{"127",	10,	127},
+	};
+	TEST_OK(kstrtos8, s8, "%hhd", test_s8_ok);
+}
+
+static void __init test_kstrtos8_fail(void)
+{
+	static DEFINE_TEST_FAIL(test_s8_fail) = {
+		{"-130",	10},
+		{"-129",	10},
+		{"128",	10},
+		{"129",	10},
+		{"254",	10},
+		{"255",	10},
+		{"256",	10},
+		{"257",	10},
+		{"32766",	10},
+		{"32767",	10},
+		{"32768",	10},
+		{"32769",	10},
+		{"65534",	10},
+		{"65535",	10},
+		{"65536",	10},
+		{"65537",	10},
+		{"2147483646",	10},
+		{"2147483647",	10},
+		{"2147483648",	10},
+		{"2147483649",	10},
+		{"4294967294",	10},
+		{"4294967295",	10},
+		{"4294967296",	10},
+		{"4294967297",	10},
+		{"9223372036854775806",	10},
+		{"9223372036854775807",	10},
+		{"9223372036854775808",	10},
+		{"9223372036854775809",	10},
+		{"18446744073709551614",	10},
+		{"18446744073709551615",	10},
+		{"18446744073709551616",	10},
+		{"18446744073709551617",	10},
+	};
+	TEST_FAIL(kstrtos8, s8, "%hhd", test_s8_fail);
+}
+
+static void __init test_kstrtoudec64_ok(void)
+{
+	DECLARE_TEST_OK(u64, struct test_udec64);
+	static DEFINE_TEST_OK(struct test_udec64, test_udec64_ok) = {
+		/* basic: integer.fraction, exact digits */
+		{"0.0",			1,	0},
+		{"1.5",			1,	15},
+		{"1.234",		3,	1234},
+		{"42.0",		1,	420},
+		/* zero */
+		{"0.0",			1,	0},
+		{"0.000",		3,	0},
+		/* integer only */
+		{"0",			1,	0},
+		{"42",			3,	42000},
+		{"123.",		2,	12300},
+		{"1",			1,	10},
+		/* fractional only (leading dot) */
+		{".5",			1,	5},
+		{".5",			0,	0},
+		{".123",		3,	123},
+		{".001",		3,	1},
+		/* zero padding: fewer fractional digits than scale */
+		{"1.2",			3,	1200},
+		{"1.2",			6,	1200000},
+		{"0.01",		3,	10},
+		{"0.1",			9,	100000000ULL},
+		{"0.01",		9,	10000000},
+		/* truncation: more fractional digits than scale */
+		{"1.23456",		3,	1234},
+		{"3.1415926535",	6,	3141592},
+		{"0.999999999",		3,	999},
+		{"1.99",		1,	19},
+		{"1.234",		0,	1},
+		/* trailing newline */
+		{"1.5\n",		1,	15},
+		{"42\n",		3,	42000},
+		/* plus sign */
+		{"+1.5",		1,	15},
+		{"+.5",			1,	5},
+		/* scale progression */
+		{"1.",			0,	1},
+		{"1.0",			1,	10},
+		{"1.00",		2,	100},
+		{"1.000",		3,	1000},
+		{"1.000000",		6,	1000000},
+		{"1.000000000",		9,	1000000000ULL},
+		/* max limit check */
+		{"18446744073.709551615",	9,	ULLONG_MAX},
+		{"18446744073709.551615",	6,	ULLONG_MAX},
+		{"0.18446744073709551615",	20,	ULLONG_MAX},
+		/* scale > 19: representable when integer part is small */
+		{"0.00000000000000000001",	20,	1},
+		{"0.1",				20,	10000000000000000000ULL},
+		{"0.00000000000000000000001",	23,	1},
+		/* truncation with scale > 19 */
+		{"0.0000000000000000000012345",	23,	123},
+		/* truncation with many excess digits */
+		{"0.00000000000000000000000000000000423",	34,	42},
+		{"1.99999999999999999999999999999999999",	3,	1999},
+	};
+	TEST_OK(kstrtoudec64, u64, "%llu", test_udec64_ok);
+}
+
+static void __init test_kstrtoudec64_fail(void)
+{
+	static DEFINE_TEST_FAIL(test_udec64_fail) = {
+		/* empty / whitespace */
+		{"",		3},
+		{"\n",		3},
+		/* minus sign (unsigned) */
+		{"-1.5",	1},
+		{"-0.5",	1},
+		/* only a decimal point */
+		{".",		3},
+		{".",		0},
+		/* only a sign */
+		{"+",		3},
+		/* non-digit characters */
+		{"abc",		3},
+		{"1.2x",	3},
+		/* leading/trailing space */
+		{" 1.5",	1},
+		{"1.5 ",	1},
+		/* overflow */
+		{"18446744073710.551615",	6},
+		{"99999999999999999999",	1},
+		/* overflow with scale > 19 */
+		{"1.0",				21},
+		{"0.2",				20},
+		{"0.18446744073709551616",	20},
+		{"1",				20},
+	};
+	TEST_FAIL(kstrtoudec64, u64, "%llu", test_udec64_fail);
+}
+
+static void __init test_kstrtodec64_ok(void)
+{
+	DECLARE_TEST_OK(s64, struct test_dec64);
+	static DEFINE_TEST_OK(struct test_dec64, test_dec64_ok) = {
+		/* basic positive */
+		{"0.0",			1,	0},
+		{"1.5",			1,	15},
+		{"1.234",		3,	1234},
+		/* basic negative */
+		{"-1.5",		1,	-15},
+		{"-1.234",		3,	-1234},
+		{"-0.5",		1,	-5},
+		{"-0.001",		3,	-1},
+		/* zero (signed) */
+		{"-0",			1,	0},
+		{"-0.0",		1,	0},
+		{"0.000",		3,	0},
+		/* integer only */
+		{"42",			3,	42000},
+		{"-42",			3,	-42000},
+		/* fractional only */
+		{".5",			1,	5},
+		{"-.5",			1,	-5},
+		/* zero padding */
+		{"1.2",			3,	1200},
+		{"-1.2",		3,	-1200},
+		{"0.01",		3,	10},
+		{"-0.01",		3,	-10},
+		/* truncation */
+		{"1.23456",		3,	1234},
+		{"-1.23456",		3,	-1234},
+		{"0.999999999",		3,	999},
+		{"-0.999999999",	3,	-999},
+		/* trailing newline */
+		{"1.5\n",		1,	15},
+		{"-1.5\n",		1,	-15},
+		/* plus sign */
+		{"+1.5",		1,	15},
+		/* limits */
+		{"9223372036.854775807",	9,	LLONG_MAX},
+		{"-9223372036.854775808",	9,	LLONG_MIN},
+		/* scale > 19 */
+		{"0.0",				20,	0},
+		{"-0.0",			20,	0},
+		{"0.00000000000000000001",	20,	1},
+		{"-0.00000000000000000001",	20,	-1},
+		{"0.009223372036854775807",	21,	LLONG_MAX},
+		{"-0.009223372036854775808",	21,	LLONG_MIN},
+	};
+	TEST_OK(kstrtodec64, s64, "%lld", test_dec64_ok);
+}
+
+static void __init test_kstrtodec64_fail(void)
+{
+	static DEFINE_TEST_FAIL(test_dec64_fail) = {
+		/* empty / whitespace */
+		{"",		3},
+		{"\n",		3},
+		/* no digits after dot */
+		{".",		3},
+		{"-.",		3},
+		/* no digits at all */
+		{"+",		3},
+		{"-",		3},
+		/* non-digit characters */
+		{"abc",		3},
+		{"-1.2x",	3},
+		/* signed overflow */
+		{"9223372036.854775808",	9},
+		{"-9223372036.854775809",	9},
+		{"99999999999999999999",	1},
+		/* signed overflow with scale > 19 */
+		{"0.1",				20},
+		{"-0.1",			20},
+		{"0.09223372036854775808",	20},
+		{"-0.09223372036854775809",	20},
+	};
+	TEST_FAIL(kstrtodec64, s64, "%lld", test_dec64_fail);
+}
+
+static int __init test_kstrtox_init(void)
+{
+	test_kstrtoull_ok();
+	test_kstrtoull_fail();
+	test_kstrtoll_ok();
+	test_kstrtoll_fail();
+
+	test_kstrtou64_ok();
+	test_kstrtou64_fail();
+	test_kstrtos64_ok();
+	test_kstrtos64_fail();
+
+	test_kstrtou32_ok();
+	test_kstrtou32_fail();
+	test_kstrtos32_ok();
+	test_kstrtos32_fail();
+
+	test_kstrtou16_ok();
+	test_kstrtou16_fail();
+	test_kstrtos16_ok();
+	test_kstrtos16_fail();
+
+	test_kstrtou8_ok();
+	test_kstrtou8_fail();
+	test_kstrtos8_ok();
+	test_kstrtos8_fail();
+
+	test_kstrtoudec64_ok();
+	test_kstrtoudec64_fail();
+	test_kstrtodec64_ok();
+	test_kstrtodec64_fail();
+
+	return -EINVAL;
+}
+module_init(test_kstrtox_init);
+MODULE_DESCRIPTION("Module test for kstrto*() APIs");
+MODULE_LICENSE("Dual BSD/GPL");