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, 45 insertions, 0 deletions

diff --git a/drivers/clk/qcom/clk-hfpll.h b/drivers/clk/qcom/clk-hfpll.h
new file mode 100644
index 000000000..27b9effcb
--- /dev/null
+++ b/drivers/clk/qcom/clk-hfpll.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __QCOM_CLK_HFPLL_H__
+#define __QCOM_CLK_HFPLL_H__
+
+#include <linux/clk-provider.h>
+#include <linux/spinlock.h>
+#include "clk-regmap.h"
+
+struct hfpll_data {
+	u32 mode_reg;
+	u32 l_reg;
+	u32 m_reg;
+	u32 n_reg;
+	u32 user_reg;
+	u32 droop_reg;
+	u32 config_reg;
+	u32 status_reg;
+	u8  lock_bit;
+
+	u32 l_val;
+	u32 droop_val;
+	u32 config_val;
+	u32 user_val;
+	u32 user_vco_mask;
+	unsigned long low_vco_max_rate;
+
+	unsigned long min_rate;
+	unsigned long max_rate;
+};
+
+struct clk_hfpll {
+	struct hfpll_data const *d;
+	int init_done;
+
+	struct clk_regmap clkr;
+	spinlock_t lock;
+};
+
+#define to_clk_hfpll(_hw) \
+	container_of(to_clk_regmap(_hw), struct clk_hfpll, clkr)
+
+extern const struct clk_ops clk_ops_hfpll;
+
+#endif