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, 47 insertions, 0 deletions

diff --git a/sound/hda/controllers/intel.h b/sound/hda/controllers/intel.h
new file mode 100644
index 000000000..4efb3b0fc
--- /dev/null
+++ b/sound/hda/controllers/intel.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ */
+#ifndef __SOUND_HDA_INTEL_H
+#define __SOUND_HDA_INTEL_H
+
+#include "hda_controller.h"
+
+struct hda_intel {
+	struct azx chip;
+
+	/* sync probing */
+	struct completion probe_wait;
+	struct delayed_work probe_work;
+
+	/* card list (for power_save trigger) */
+	struct list_head list;
+
+	/* extra flags */
+	unsigned int irq_pending_warned:1;
+	unsigned int probe_continued:1;
+	unsigned int runtime_pm_disabled:1;
+
+	/* vga_switcheroo setup */
+	unsigned int use_vga_switcheroo:1;
+	unsigned int vga_switcheroo_registered:1;
+	unsigned int init_failed:1; /* delayed init failed */
+	unsigned int freed:1; /* resources already released */
+
+	bool need_i915_power:1; /* the hda controller needs i915 power */
+
+	int probe_retry;	/* being probe-retry */
+};
+
+struct hda_intel_stream {
+	struct azx_dev azx_dev;
+
+	/* for pending irqs */
+	struct hda_intel *hda;
+	struct work_struct irq_pending_work;
+	bool irq_pending;
+};
+
+#define azx_dev_to_istream(azx_dev) \
+	container_of(azx_dev, struct hda_intel_stream, azx_dev)
+
+#endif