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, 25 insertions, 0 deletions

diff --git a/drivers/usb/chipidea/otg.h b/drivers/usb/chipidea/otg.h
new file mode 100644
index 000000000..87629b81e
--- /dev/null
+++ b/drivers/usb/chipidea/otg.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2013-2014 Freescale Semiconductor, Inc.
+ *
+ * Author: Peter Chen
+ */
+
+#ifndef __DRIVERS_USB_CHIPIDEA_OTG_H
+#define __DRIVERS_USB_CHIPIDEA_OTG_H
+
+u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask);
+void hw_write_otgsc(struct ci_hdrc *ci, u32 mask, u32 data);
+int ci_hdrc_otg_init(struct ci_hdrc *ci);
+void ci_hdrc_otg_destroy(struct ci_hdrc *ci);
+enum ci_role ci_otg_role(struct ci_hdrc *ci);
+void ci_handle_vbus_change(struct ci_hdrc *ci);
+void ci_handle_id_switch(struct ci_hdrc *ci);
+static inline void ci_otg_queue_work(struct ci_hdrc *ci)
+{
+	disable_irq_nosync(ci->irq);
+	if (queue_work(ci->wq, &ci->work) == false)
+		enable_irq(ci->irq);
+}
+
+#endif /* __DRIVERS_USB_CHIPIDEA_OTG_H */