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, 72 insertions, 0 deletions

diff --git a/sound/soc/sof/sof-client-probes.h b/sound/soc/sof/sof-client-probes.h
new file mode 100644
index 000000000..47d0582b8
--- /dev/null
+++ b/sound/soc/sof/sof-client-probes.h
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __SOF_CLIENT_PROBES_H
+#define __SOF_CLIENT_PROBES_H
+
+struct snd_compr_stream;
+struct snd_compr_tstamp64;
+struct snd_compr_params;
+struct sof_client_dev;
+struct snd_soc_dai;
+
+/*
+ * Callbacks used on platforms where the control for audio is split between
+ * DSP and host, like HDA.
+ */
+struct sof_probes_host_ops {
+	int (*startup)(struct sof_client_dev *cdev, struct snd_compr_stream *cstream,
+		       struct snd_soc_dai *dai, u32 *stream_id);
+	int (*shutdown)(struct sof_client_dev *cdev, struct snd_compr_stream *cstream,
+			struct snd_soc_dai *dai);
+	int (*set_params)(struct sof_client_dev *cdev, struct snd_compr_stream *cstream,
+			  struct snd_compr_params *params,
+			  struct snd_soc_dai *dai);
+	int (*trigger)(struct sof_client_dev *cdev, struct snd_compr_stream *cstream,
+		       int cmd, struct snd_soc_dai *dai);
+	int (*pointer)(struct sof_client_dev *cdev, struct snd_compr_stream *cstream,
+		       struct snd_compr_tstamp64 *tstamp,
+		       struct snd_soc_dai *dai);
+};
+
+struct sof_probe_point_desc {
+	unsigned int buffer_id;
+	unsigned int purpose;
+	unsigned int stream_tag;
+} __packed;
+
+enum sof_probe_info_type {
+	PROBES_INFO_ACTIVE_PROBES,
+	PROBES_INFO_AVAILABE_PROBES,
+};
+
+struct sof_probes_ipc_ops {
+	int (*init)(struct sof_client_dev *cdev, u32 stream_tag,
+		    size_t buffer_size);
+	int (*deinit)(struct sof_client_dev *cdev);
+	int (*points_info)(struct sof_client_dev *cdev,
+			   struct sof_probe_point_desc **desc,
+			   size_t *num_desc, enum sof_probe_info_type type);
+	int (*point_print)(struct sof_client_dev *cdev, char *buf, size_t size,
+			   struct sof_probe_point_desc *desc);
+	int (*points_add)(struct sof_client_dev *cdev,
+			  struct sof_probe_point_desc *desc,
+			  size_t num_desc);
+	int (*points_remove)(struct sof_client_dev *cdev,
+			     unsigned int *buffer_id, size_t num_buffer_id);
+};
+
+extern const struct sof_probes_ipc_ops ipc3_probe_ops;
+extern const struct sof_probes_ipc_ops ipc4_probe_ops;
+
+struct sof_probes_priv {
+	struct dentry *dfs_points;
+	struct dentry *dfs_points_remove;
+	u32 extractor_stream_tag;
+	struct snd_soc_card card;
+	void *ipc_priv;
+
+	const struct sof_probes_host_ops *host_ops;
+	const struct sof_probes_ipc_ops *ipc_ops;
+};
+
+#endif