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, 98 insertions, 0 deletions

diff --git a/drivers/clk/versatile/clk-versatile.c b/drivers/clk/versatile/clk-versatile.c
new file mode 100644
index 000000000..8ed7a179f
--- /dev/null
+++ b/drivers/clk/versatile/clk-versatile.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Clock driver for the ARM Integrator/AP, Integrator/CP, Versatile AB and
+ * Versatile PB boards.
+ * Copyright (C) 2012 Linus Walleij
+ */
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include "icst.h"
+#include "clk-icst.h"
+
+#define INTEGRATOR_HDR_LOCK_OFFSET	0x14
+
+#define VERSATILE_SYS_OSCCLCD_OFFSET	0x1c
+#define VERSATILE_SYS_LOCK_OFFSET	0x20
+
+/* Base offset for the core module */
+static void __iomem *cm_base;
+
+static const struct icst_params cp_auxosc_params = {
+	.vco_max	= ICST525_VCO_MAX_5V,
+	.vco_min	= ICST525_VCO_MIN,
+	.vd_min 	= 8,
+	.vd_max 	= 263,
+	.rd_min 	= 3,
+	.rd_max 	= 65,
+	.s2div		= icst525_s2div,
+	.idx2s		= icst525_idx2s,
+};
+
+static const struct clk_icst_desc cm_auxosc_desc __initconst = {
+	.params = &cp_auxosc_params,
+	.vco_offset = 0x1c,
+	.lock_offset = INTEGRATOR_HDR_LOCK_OFFSET,
+};
+
+static const struct icst_params versatile_auxosc_params = {
+	.vco_max	= ICST307_VCO_MAX,
+	.vco_min	= ICST307_VCO_MIN,
+	.vd_min		= 4 + 8,
+	.vd_max		= 511 + 8,
+	.rd_min		= 1 + 2,
+	.rd_max		= 127 + 2,
+	.s2div		= icst307_s2div,
+	.idx2s		= icst307_idx2s,
+};
+
+static const struct clk_icst_desc versatile_auxosc_desc __initconst = {
+	.params = &versatile_auxosc_params,
+	.vco_offset = VERSATILE_SYS_OSCCLCD_OFFSET,
+	.lock_offset = VERSATILE_SYS_LOCK_OFFSET,
+};
+static void __init cm_osc_setup(struct device_node *np,
+				const struct clk_icst_desc *desc)
+{
+	struct clk *clk;
+	const char *clk_name = np->name;
+	const char *parent_name;
+
+	if (!cm_base) {
+		/* Remap the core module base if not done yet */
+		struct device_node *parent;
+
+		parent = of_get_parent(np);
+		if (!parent) {
+			pr_err("no parent on core module clock\n");
+			return;
+		}
+		cm_base = of_iomap(parent, 0);
+		of_node_put(parent);
+		if (!cm_base) {
+			pr_err("could not remap core module base\n");
+			return;
+		}
+	}
+
+	parent_name = of_clk_get_parent_name(np, 0);
+	clk = icst_clk_register(NULL, desc, clk_name, parent_name, cm_base);
+	if (!IS_ERR(clk))
+		of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}
+
+static void __init of_integrator_cm_osc_setup(struct device_node *np)
+{
+	cm_osc_setup(np, &cm_auxosc_desc);
+}
+CLK_OF_DECLARE(integrator_cm_auxosc_clk,
+	"arm,integrator-cm-auxosc", of_integrator_cm_osc_setup);
+
+static void __init of_versatile_cm_osc_setup(struct device_node *np)
+{
+	cm_osc_setup(np, &versatile_auxosc_desc);
+}
+CLK_OF_DECLARE(versatile_cm_auxosc_clk,
+	       "arm,versatile-cm-auxosc", of_versatile_cm_osc_setup);