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, 127 insertions, 0 deletions

diff --git a/drivers/clk/sprd/pll.h b/drivers/clk/sprd/pll.h
new file mode 100644
index 000000000..6558f50d0
--- /dev/null
+++ b/drivers/clk/sprd/pll.h
@@ -0,0 +1,127 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+//
+// Spreadtrum pll clock driver
+//
+// Copyright (C) 2015~2017 Spreadtrum, Inc.
+// Author: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
+
+#ifndef _SPRD_PLL_H_
+#define _SPRD_PLL_H_
+
+#include "common.h"
+
+struct reg_cfg {
+	u32 val;
+	u32 msk;
+};
+
+struct clk_bit_field {
+	u8 shift;
+	u8 width;
+};
+
+enum {
+	PLL_LOCK_DONE,
+	PLL_DIV_S,
+	PLL_MOD_EN,
+	PLL_SDM_EN,
+	PLL_REFIN,
+	PLL_IBIAS,
+	PLL_N,
+	PLL_NINT,
+	PLL_KINT,
+	PLL_PREDIV,
+	PLL_POSTDIV,
+
+	PLL_FACT_MAX
+};
+
+/*
+ * struct sprd_pll - definition of adjustable pll clock
+ *
+ * @reg:	registers used to set the configuration of pll clock,
+ *		reg[0] shows how many registers this pll clock uses.
+ * @itable:	pll ibias table, itable[0] means how many items this
+ *		table includes
+ * @udelay	delay time after setting rate
+ * @factors	used to calculate the pll clock rate
+ * @fvco:	fvco threshold rate
+ * @fflag:	fvco flag
+ */
+struct sprd_pll {
+	u32 regs_num;
+	const u64 *itable;
+	const struct clk_bit_field *factors;
+	u16 udelay;
+	u16 k1;
+	u16 k2;
+	u16 fflag;
+	u64 fvco;
+
+	struct sprd_clk_common	common;
+};
+
+#define SPRD_PLL_HW_INIT_FN(_struct, _name, _parent, _reg,	\
+			    _regs_num, _itable, _factors,	\
+			    _udelay, _k1, _k2, _fflag,		\
+			    _fvco, _fn)				\
+	struct sprd_pll _struct = {				\
+		.regs_num	= _regs_num,			\
+		.itable		= _itable,			\
+		.factors	= _factors,			\
+		.udelay		= _udelay,			\
+		.k1		= _k1,				\
+		.k2		= _k2,				\
+		.fflag		= _fflag,			\
+		.fvco		= _fvco,			\
+		.common		= {				\
+			.regmap		= NULL,			\
+			.reg		= _reg,			\
+			.hw.init	= _fn(_name, _parent,	\
+					      &sprd_pll_ops, 0),\
+		},						\
+	}
+
+#define SPRD_PLL_WITH_ITABLE_K_FVCO(_struct, _name, _parent, _reg,	\
+				    _regs_num, _itable, _factors,	\
+				    _udelay, _k1, _k2, _fflag, _fvco)	\
+	SPRD_PLL_HW_INIT_FN(_struct, _name, _parent, _reg, _regs_num,	\
+			    _itable, _factors, _udelay, _k1, _k2,	\
+			    _fflag, _fvco, CLK_HW_INIT)
+
+#define SPRD_PLL_WITH_ITABLE_K(_struct, _name, _parent, _reg,		\
+			       _regs_num, _itable, _factors,		\
+			       _udelay, _k1, _k2)			\
+	SPRD_PLL_WITH_ITABLE_K_FVCO(_struct, _name, _parent, _reg,	\
+				    _regs_num, _itable, _factors,	\
+				    _udelay, _k1, _k2, 0, 0)
+
+#define SPRD_PLL_WITH_ITABLE_1K(_struct, _name, _parent, _reg,		\
+				_regs_num, _itable, _factors, _udelay)	\
+	SPRD_PLL_WITH_ITABLE_K_FVCO(_struct, _name, _parent, _reg,	\
+				    _regs_num, _itable, _factors,	\
+				    _udelay, 1000, 1000, 0, 0)
+
+#define SPRD_PLL_FW_NAME(_struct, _name, _parent, _reg, _regs_num,	\
+			 _itable, _factors, _udelay, _k1, _k2,		\
+			 _fflag, _fvco)					\
+	SPRD_PLL_HW_INIT_FN(_struct, _name, _parent, _reg, _regs_num,	\
+			    _itable, _factors, _udelay, _k1, _k2,	\
+			    _fflag, _fvco, CLK_HW_INIT_FW_NAME)
+
+#define SPRD_PLL_HW(_struct, _name, _parent, _reg, _regs_num, _itable,	\
+		    _factors, _udelay, _k1, _k2, _fflag, _fvco)		\
+	SPRD_PLL_HW_INIT_FN(_struct, _name, _parent, _reg, _regs_num,	\
+			    _itable, _factors, _udelay, _k1, _k2,	\
+			    _fflag, _fvco, CLK_HW_INIT_HW)
+
+static inline struct sprd_pll *hw_to_sprd_pll(struct clk_hw *hw)
+{
+	struct sprd_clk_common *common = hw_to_sprd_clk_common(hw);
+
+	return container_of(common, struct sprd_pll, common);
+}
+
+extern const struct clk_ops sprd_pll_ops;
+
+#endif /* _SPRD_PLL_H_ */