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, 465 insertions, 0 deletions

diff --git a/drivers/clk/clk-gate_test.c b/drivers/clk/clk-gate_test.c
new file mode 100644
index 000000000..e276cd974
--- /dev/null
+++ b/drivers/clk/clk-gate_test.c
@@ -0,0 +1,465 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Kunit tests for clk gate
+ */
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/platform_device.h>
+
+#include <kunit/test.h>
+
+static void clk_gate_register_test_dev(struct kunit *test)
+{
+	struct clk_hw *ret;
+	struct platform_device *pdev;
+
+	pdev = platform_device_register_simple("test_gate_device", -1, NULL, 0);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	ret = clk_hw_register_gate(&pdev->dev, "test_gate", NULL, 0, NULL,
+				   0, 0, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ret);
+	KUNIT_EXPECT_STREQ(test, "test_gate", clk_hw_get_name(ret));
+	KUNIT_EXPECT_EQ(test, 0UL, clk_hw_get_flags(ret));
+
+	clk_hw_unregister_gate(ret);
+	platform_device_put(pdev);
+}
+
+static void clk_gate_register_test_parent_names(struct kunit *test)
+{
+	struct clk_hw *parent;
+	struct clk_hw *ret;
+
+	parent = clk_hw_register_fixed_rate(NULL, "test_parent", NULL, 0,
+					    1000000);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent);
+
+	ret = clk_hw_register_gate(NULL, "test_gate", "test_parent", 0, NULL,
+				   0, 0, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ret);
+	KUNIT_EXPECT_PTR_EQ(test, parent, clk_hw_get_parent(ret));
+
+	clk_hw_unregister_gate(ret);
+	clk_hw_unregister_fixed_rate(parent);
+}
+
+static void clk_gate_register_test_parent_data(struct kunit *test)
+{
+	struct clk_hw *parent;
+	struct clk_hw *ret;
+	struct clk_parent_data pdata = { };
+
+	parent = clk_hw_register_fixed_rate(NULL, "test_parent", NULL, 0,
+					    1000000);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent);
+	pdata.hw = parent;
+
+	ret = clk_hw_register_gate_parent_data(NULL, "test_gate", &pdata, 0,
+					       NULL, 0, 0, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ret);
+	KUNIT_EXPECT_PTR_EQ(test, parent, clk_hw_get_parent(ret));
+
+	clk_hw_unregister_gate(ret);
+	clk_hw_unregister_fixed_rate(parent);
+}
+
+static void clk_gate_register_test_parent_data_legacy(struct kunit *test)
+{
+	struct clk_hw *parent;
+	struct clk_hw *ret;
+	struct clk_parent_data pdata = { };
+
+	parent = clk_hw_register_fixed_rate(NULL, "test_parent", NULL, 0,
+					    1000000);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent);
+	pdata.name = "test_parent";
+
+	ret = clk_hw_register_gate_parent_data(NULL, "test_gate", &pdata, 0,
+					       NULL, 0, 0, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ret);
+	KUNIT_EXPECT_PTR_EQ(test, parent, clk_hw_get_parent(ret));
+
+	clk_hw_unregister_gate(ret);
+	clk_hw_unregister_fixed_rate(parent);
+}
+
+static void clk_gate_register_test_parent_hw(struct kunit *test)
+{
+	struct clk_hw *parent;
+	struct clk_hw *ret;
+
+	parent = clk_hw_register_fixed_rate(NULL, "test_parent", NULL, 0,
+					    1000000);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent);
+
+	ret = clk_hw_register_gate_parent_hw(NULL, "test_gate", parent, 0, NULL,
+					     0, 0, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ret);
+	KUNIT_EXPECT_PTR_EQ(test, parent, clk_hw_get_parent(ret));
+
+	clk_hw_unregister_gate(ret);
+	clk_hw_unregister_fixed_rate(parent);
+}
+
+static void clk_gate_register_test_hiword_invalid(struct kunit *test)
+{
+	struct clk_hw *ret;
+
+	ret = clk_hw_register_gate(NULL, "test_gate", NULL, 0, NULL,
+				   20, CLK_GATE_HIWORD_MASK, NULL);
+
+	KUNIT_EXPECT_TRUE(test, IS_ERR(ret));
+}
+
+static struct kunit_case clk_gate_register_test_cases[] = {
+	KUNIT_CASE(clk_gate_register_test_dev),
+	KUNIT_CASE(clk_gate_register_test_parent_names),
+	KUNIT_CASE(clk_gate_register_test_parent_data),
+	KUNIT_CASE(clk_gate_register_test_parent_data_legacy),
+	KUNIT_CASE(clk_gate_register_test_parent_hw),
+	KUNIT_CASE(clk_gate_register_test_hiword_invalid),
+	{}
+};
+
+static struct kunit_suite clk_gate_register_test_suite = {
+	.name = "clk-gate-register-test",
+	.test_cases = clk_gate_register_test_cases,
+};
+
+struct clk_gate_test_context {
+	void __iomem *fake_mem;
+	struct clk_hw *hw;
+	struct clk_hw *parent;
+	__le32 fake_reg; /* Keep at end, KASAN can detect out of bounds */
+};
+
+static struct clk_gate_test_context *clk_gate_test_alloc_ctx(struct kunit *test)
+{
+	struct clk_gate_test_context *ctx;
+
+	test->priv = ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+	ctx->fake_mem = (void __force __iomem *)&ctx->fake_reg;
+
+	return ctx;
+}
+
+static void clk_gate_test_parent_rate(struct kunit *test)
+{
+	struct clk_gate_test_context *ctx = test->priv;
+	struct clk_hw *parent = ctx->parent;
+	struct clk_hw *hw = ctx->hw;
+	unsigned long prate = clk_hw_get_rate(parent);
+	unsigned long rate = clk_hw_get_rate(hw);
+
+	KUNIT_EXPECT_EQ(test, prate, rate);
+}
+
+static void clk_gate_test_enable(struct kunit *test)
+{
+	struct clk_gate_test_context *ctx = test->priv;
+	struct clk_hw *parent = ctx->parent;
+	struct clk_hw *hw = ctx->hw;
+	struct clk *clk = hw->clk;
+	u32 enable_val = BIT(5);
+
+	KUNIT_ASSERT_EQ(test, clk_prepare_enable(clk), 0);
+
+	KUNIT_EXPECT_EQ(test, enable_val, le32_to_cpu(ctx->fake_reg));
+	KUNIT_EXPECT_TRUE(test, clk_hw_is_enabled(hw));
+	KUNIT_EXPECT_TRUE(test, clk_hw_is_prepared(hw));
+	KUNIT_EXPECT_TRUE(test, clk_hw_is_enabled(parent));
+	KUNIT_EXPECT_TRUE(test, clk_hw_is_prepared(parent));
+}
+
+static void clk_gate_test_disable(struct kunit *test)
+{
+	struct clk_gate_test_context *ctx = test->priv;
+	struct clk_hw *parent = ctx->parent;
+	struct clk_hw *hw = ctx->hw;
+	struct clk *clk = hw->clk;
+	u32 enable_val = BIT(5);
+	u32 disable_val = 0;
+
+	KUNIT_ASSERT_EQ(test, clk_prepare_enable(clk), 0);
+	KUNIT_ASSERT_EQ(test, enable_val, le32_to_cpu(ctx->fake_reg));
+
+	clk_disable_unprepare(clk);
+	KUNIT_EXPECT_EQ(test, disable_val, le32_to_cpu(ctx->fake_reg));
+	KUNIT_EXPECT_FALSE(test, clk_hw_is_enabled(hw));
+	KUNIT_EXPECT_FALSE(test, clk_hw_is_prepared(hw));
+	KUNIT_EXPECT_FALSE(test, clk_hw_is_enabled(parent));
+	KUNIT_EXPECT_FALSE(test, clk_hw_is_prepared(parent));
+}
+
+static struct kunit_case clk_gate_test_cases[] = {
+	KUNIT_CASE(clk_gate_test_parent_rate),
+	KUNIT_CASE(clk_gate_test_enable),
+	KUNIT_CASE(clk_gate_test_disable),
+	{}
+};
+
+static int clk_gate_test_init(struct kunit *test)
+{
+	struct clk_hw *parent;
+	struct clk_hw *hw;
+	struct clk_gate_test_context *ctx;
+
+	ctx = clk_gate_test_alloc_ctx(test);
+	parent = clk_hw_register_fixed_rate(NULL, "test_parent", NULL, 0,
+					    2000000);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent);
+
+	hw = clk_hw_register_gate_parent_hw(NULL, "test_gate", parent, 0,
+					    ctx->fake_mem, 5, 0, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, hw);
+
+	ctx->hw = hw;
+	ctx->parent = parent;
+
+	return 0;
+}
+
+static void clk_gate_test_exit(struct kunit *test)
+{
+	struct clk_gate_test_context *ctx = test->priv;
+
+	clk_hw_unregister_gate(ctx->hw);
+	clk_hw_unregister_fixed_rate(ctx->parent);
+}
+
+static struct kunit_suite clk_gate_test_suite = {
+	.name = "clk-gate-test",
+	.init = clk_gate_test_init,
+	.exit = clk_gate_test_exit,
+	.test_cases = clk_gate_test_cases,
+};
+
+static void clk_gate_test_invert_enable(struct kunit *test)
+{
+	struct clk_gate_test_context *ctx = test->priv;
+	struct clk_hw *parent = ctx->parent;
+	struct clk_hw *hw = ctx->hw;
+	struct clk *clk = hw->clk;
+	u32 enable_val = 0;
+
+	KUNIT_ASSERT_EQ(test, clk_prepare_enable(clk), 0);
+
+	KUNIT_EXPECT_EQ(test, enable_val, le32_to_cpu(ctx->fake_reg));
+	KUNIT_EXPECT_TRUE(test, clk_hw_is_enabled(hw));
+	KUNIT_EXPECT_TRUE(test, clk_hw_is_prepared(hw));
+	KUNIT_EXPECT_TRUE(test, clk_hw_is_enabled(parent));
+	KUNIT_EXPECT_TRUE(test, clk_hw_is_prepared(parent));
+}
+
+static void clk_gate_test_invert_disable(struct kunit *test)
+{
+	struct clk_gate_test_context *ctx = test->priv;
+	struct clk_hw *parent = ctx->parent;
+	struct clk_hw *hw = ctx->hw;
+	struct clk *clk = hw->clk;
+	u32 enable_val = 0;
+	u32 disable_val = BIT(15);
+
+	KUNIT_ASSERT_EQ(test, clk_prepare_enable(clk), 0);
+	KUNIT_ASSERT_EQ(test, enable_val, le32_to_cpu(ctx->fake_reg));
+
+	clk_disable_unprepare(clk);
+	KUNIT_EXPECT_EQ(test, disable_val, le32_to_cpu(ctx->fake_reg));
+	KUNIT_EXPECT_FALSE(test, clk_hw_is_enabled(hw));
+	KUNIT_EXPECT_FALSE(test, clk_hw_is_prepared(hw));
+	KUNIT_EXPECT_FALSE(test, clk_hw_is_enabled(parent));
+	KUNIT_EXPECT_FALSE(test, clk_hw_is_prepared(parent));
+}
+
+static struct kunit_case clk_gate_test_invert_cases[] = {
+	KUNIT_CASE(clk_gate_test_invert_enable),
+	KUNIT_CASE(clk_gate_test_invert_disable),
+	{}
+};
+
+static int clk_gate_test_invert_init(struct kunit *test)
+{
+	struct clk_hw *parent;
+	struct clk_hw *hw;
+	struct clk_gate_test_context *ctx;
+
+	ctx = clk_gate_test_alloc_ctx(test);
+	parent = clk_hw_register_fixed_rate(NULL, "test_parent", NULL, 0,
+					    2000000);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent);
+
+	ctx->fake_reg = cpu_to_le32(BIT(15)); /* Default to off */
+	hw = clk_hw_register_gate_parent_hw(NULL, "test_gate", parent, 0,
+					    ctx->fake_mem, 15,
+					    CLK_GATE_SET_TO_DISABLE, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, hw);
+
+	ctx->hw = hw;
+	ctx->parent = parent;
+
+	return 0;
+}
+
+static struct kunit_suite clk_gate_test_invert_suite = {
+	.name = "clk-gate-invert-test",
+	.init = clk_gate_test_invert_init,
+	.exit = clk_gate_test_exit,
+	.test_cases = clk_gate_test_invert_cases,
+};
+
+static void clk_gate_test_hiword_enable(struct kunit *test)
+{
+	struct clk_gate_test_context *ctx = test->priv;
+	struct clk_hw *parent = ctx->parent;
+	struct clk_hw *hw = ctx->hw;
+	struct clk *clk = hw->clk;
+	u32 enable_val = BIT(9) | BIT(9 + 16);
+
+	KUNIT_ASSERT_EQ(test, clk_prepare_enable(clk), 0);
+
+	KUNIT_EXPECT_EQ(test, enable_val, le32_to_cpu(ctx->fake_reg));
+	KUNIT_EXPECT_TRUE(test, clk_hw_is_enabled(hw));
+	KUNIT_EXPECT_TRUE(test, clk_hw_is_prepared(hw));
+	KUNIT_EXPECT_TRUE(test, clk_hw_is_enabled(parent));
+	KUNIT_EXPECT_TRUE(test, clk_hw_is_prepared(parent));
+}
+
+static void clk_gate_test_hiword_disable(struct kunit *test)
+{
+	struct clk_gate_test_context *ctx = test->priv;
+	struct clk_hw *parent = ctx->parent;
+	struct clk_hw *hw = ctx->hw;
+	struct clk *clk = hw->clk;
+	u32 enable_val = BIT(9) | BIT(9 + 16);
+	u32 disable_val = BIT(9 + 16);
+
+	KUNIT_ASSERT_EQ(test, clk_prepare_enable(clk), 0);
+	KUNIT_ASSERT_EQ(test, enable_val, le32_to_cpu(ctx->fake_reg));
+
+	clk_disable_unprepare(clk);
+	KUNIT_EXPECT_EQ(test, disable_val, le32_to_cpu(ctx->fake_reg));
+	KUNIT_EXPECT_FALSE(test, clk_hw_is_enabled(hw));
+	KUNIT_EXPECT_FALSE(test, clk_hw_is_prepared(hw));
+	KUNIT_EXPECT_FALSE(test, clk_hw_is_enabled(parent));
+	KUNIT_EXPECT_FALSE(test, clk_hw_is_prepared(parent));
+}
+
+static struct kunit_case clk_gate_test_hiword_cases[] = {
+	KUNIT_CASE(clk_gate_test_hiword_enable),
+	KUNIT_CASE(clk_gate_test_hiword_disable),
+	{}
+};
+
+static int clk_gate_test_hiword_init(struct kunit *test)
+{
+	struct clk_hw *parent;
+	struct clk_hw *hw;
+	struct clk_gate_test_context *ctx;
+
+	ctx = clk_gate_test_alloc_ctx(test);
+	parent = clk_hw_register_fixed_rate(NULL, "test_parent", NULL, 0,
+					    2000000);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent);
+
+	hw = clk_hw_register_gate_parent_hw(NULL, "test_gate", parent, 0,
+					    ctx->fake_mem, 9,
+					    CLK_GATE_HIWORD_MASK, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, hw);
+
+	ctx->hw = hw;
+	ctx->parent = parent;
+
+	return 0;
+}
+
+static struct kunit_suite clk_gate_test_hiword_suite = {
+	.name = "clk-gate-hiword-test",
+	.init = clk_gate_test_hiword_init,
+	.exit = clk_gate_test_exit,
+	.test_cases = clk_gate_test_hiword_cases,
+};
+
+static void clk_gate_test_is_enabled(struct kunit *test)
+{
+	struct clk_hw *hw;
+	struct clk_gate_test_context *ctx;
+
+	ctx = clk_gate_test_alloc_ctx(test);
+	ctx->fake_reg = cpu_to_le32(BIT(7));
+	hw = clk_hw_register_gate(NULL, "test_gate", NULL, 0, ctx->fake_mem, 7,
+				  0, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, hw);
+	KUNIT_ASSERT_TRUE(test, clk_hw_is_enabled(hw));
+
+	clk_hw_unregister_gate(hw);
+}
+
+static void clk_gate_test_is_disabled(struct kunit *test)
+{
+	struct clk_hw *hw;
+	struct clk_gate_test_context *ctx;
+
+	ctx = clk_gate_test_alloc_ctx(test);
+	ctx->fake_reg = cpu_to_le32(BIT(4));
+	hw = clk_hw_register_gate(NULL, "test_gate", NULL, 0, ctx->fake_mem, 7,
+				  0, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, hw);
+	KUNIT_ASSERT_FALSE(test, clk_hw_is_enabled(hw));
+
+	clk_hw_unregister_gate(hw);
+}
+
+static void clk_gate_test_is_enabled_inverted(struct kunit *test)
+{
+	struct clk_hw *hw;
+	struct clk_gate_test_context *ctx;
+
+	ctx = clk_gate_test_alloc_ctx(test);
+	ctx->fake_reg = cpu_to_le32(BIT(31));
+	hw = clk_hw_register_gate(NULL, "test_gate", NULL, 0, ctx->fake_mem, 2,
+				  CLK_GATE_SET_TO_DISABLE, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, hw);
+	KUNIT_ASSERT_TRUE(test, clk_hw_is_enabled(hw));
+
+	clk_hw_unregister_gate(hw);
+}
+
+static void clk_gate_test_is_disabled_inverted(struct kunit *test)
+{
+	struct clk_hw *hw;
+	struct clk_gate_test_context *ctx;
+
+	ctx = clk_gate_test_alloc_ctx(test);
+	ctx->fake_reg = cpu_to_le32(BIT(29));
+	hw = clk_hw_register_gate(NULL, "test_gate", NULL, 0, ctx->fake_mem, 29,
+				  CLK_GATE_SET_TO_DISABLE, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, hw);
+	KUNIT_ASSERT_FALSE(test, clk_hw_is_enabled(hw));
+
+	clk_hw_unregister_gate(hw);
+}
+
+static struct kunit_case clk_gate_test_enabled_cases[] = {
+	KUNIT_CASE(clk_gate_test_is_enabled),
+	KUNIT_CASE(clk_gate_test_is_disabled),
+	KUNIT_CASE(clk_gate_test_is_enabled_inverted),
+	KUNIT_CASE(clk_gate_test_is_disabled_inverted),
+	{}
+};
+
+static struct kunit_suite clk_gate_test_enabled_suite = {
+	.name = "clk-gate-is_enabled-test",
+	.test_cases = clk_gate_test_enabled_cases,
+};
+
+kunit_test_suites(
+	&clk_gate_register_test_suite,
+	&clk_gate_test_suite,
+	&clk_gate_test_invert_suite,
+	&clk_gate_test_hiword_suite,
+	&clk_gate_test_enabled_suite
+);
+MODULE_DESCRIPTION("Kunit tests for clk gate");
+MODULE_LICENSE("GPL v2");