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, 167 insertions, 0 deletions

diff --git a/drivers/media/firewire/firedtv.h b/drivers/media/firewire/firedtv.h
new file mode 100644
index 000000000..190bb1a57
--- /dev/null
+++ b/drivers/media/firewire/firedtv.h
@@ -0,0 +1,167 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * FireDTV driver (formerly known as FireSAT)
+ *
+ * Copyright (C) 2004 Andreas Monitzer <andy@monitzer.com>
+ * Copyright (C) 2008 Henrik Kurelid <henrik@kurelid.se>
+ */
+
+#ifndef _FIREDTV_H
+#define _FIREDTV_H
+
+#include <linux/time.h>
+#include <linux/dvb/dmx.h>
+#include <linux/dvb/frontend.h>
+#include <linux/list.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/spinlock_types.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+
+#include <media/demux.h>
+#include <media/dmxdev.h>
+#include <media/dvb_demux.h>
+#include <media/dvb_frontend.h>
+#include <media/dvb_net.h>
+#include <media/dvbdev.h>
+
+struct firedtv_tuner_status {
+	unsigned active_system:8;
+	unsigned searching:1;
+	unsigned moving:1;
+	unsigned no_rf:1;
+	unsigned input:1;
+	unsigned selected_antenna:7;
+	unsigned ber:32;
+	unsigned signal_strength:8;
+	unsigned raster_frequency:2;
+	unsigned rf_frequency:22;
+	unsigned man_dep_info_length:8;
+	unsigned front_end_error:1;
+	unsigned antenna_error:1;
+	unsigned front_end_power_status:1;
+	unsigned power_supply:1;
+	unsigned carrier_noise_ratio:16;
+	unsigned power_supply_voltage:8;
+	unsigned antenna_voltage:8;
+	unsigned firewire_bus_voltage:8;
+	unsigned ca_mmi:1;
+	unsigned ca_pmt_reply:1;
+	unsigned ca_date_time_request:1;
+	unsigned ca_application_info:1;
+	unsigned ca_module_present_status:1;
+	unsigned ca_dvb_flag:1;
+	unsigned ca_error_flag:1;
+	unsigned ca_initialization_status:1;
+};
+
+enum model_type {
+	FIREDTV_UNKNOWN = 0,
+	FIREDTV_DVB_S   = 1,
+	FIREDTV_DVB_C   = 2,
+	FIREDTV_DVB_T   = 3,
+	FIREDTV_DVB_S2  = 4,
+};
+
+struct device;
+struct input_dev;
+struct fdtv_ir_context;
+
+struct firedtv {
+	struct device *device;
+	struct list_head list;
+
+	struct dvb_adapter	adapter;
+	struct dmxdev		dmxdev;
+	struct dvb_demux	demux;
+	struct dmx_frontend	frontend;
+	struct dvb_net		dvbnet;
+	struct dvb_frontend	fe;
+
+	struct dvb_device	*cadev;
+	int			ca_last_command;
+	int			ca_time_interval;
+
+	struct mutex		avc_mutex;
+	wait_queue_head_t	avc_wait;
+	bool			avc_reply_received;
+	struct work_struct	remote_ctrl_work;
+	struct input_dev	*remote_ctrl_dev;
+
+	enum model_type		type;
+	char			subunit;
+	s8			isochannel;
+	struct fdtv_ir_context	*ir_context;
+
+	enum fe_sec_voltage	voltage;
+	enum fe_sec_tone_mode	tone;
+
+	struct mutex		demux_mutex;
+	unsigned long		channel_active;
+	u16			channel_pid[16];
+
+	int			avc_data_length;
+	u8			avc_data[512];
+};
+
+/* firedtv-avc.c */
+int avc_recv(struct firedtv *fdtv, void *data, size_t length);
+int avc_tuner_status(struct firedtv *fdtv, struct firedtv_tuner_status *stat);
+struct dtv_frontend_properties;
+int avc_tuner_dsd(struct firedtv *fdtv, struct dtv_frontend_properties *params);
+int avc_tuner_set_pids(struct firedtv *fdtv, unsigned char pidc, u16 pid[]);
+int avc_tuner_get_ts(struct firedtv *fdtv);
+int avc_identify_subunit(struct firedtv *fdtv);
+struct dvb_diseqc_master_cmd;
+int avc_lnb_control(struct firedtv *fdtv, char voltage, char burst,
+		    char conttone, char nrdiseq,
+		    struct dvb_diseqc_master_cmd *diseqcmd);
+void avc_remote_ctrl_work(struct work_struct *work);
+int avc_register_remote_control(struct firedtv *fdtv);
+int avc_ca_app_info(struct firedtv *fdtv, unsigned char *app_info,
+		    unsigned int *len);
+int avc_ca_info(struct firedtv *fdtv, unsigned char *app_info,
+		unsigned int *len);
+int avc_ca_reset(struct firedtv *fdtv);
+int avc_ca_pmt(struct firedtv *fdtv, char *app_info, int length);
+int avc_ca_get_time_date(struct firedtv *fdtv, int *interval);
+int avc_ca_enter_menu(struct firedtv *fdtv);
+int avc_ca_get_mmi(struct firedtv *fdtv, char *mmi_object, unsigned int *len);
+int cmp_establish_pp_connection(struct firedtv *fdtv, int plug, int channel);
+void cmp_break_pp_connection(struct firedtv *fdtv, int plug, int channel);
+
+/* firedtv-ci.c */
+int fdtv_ca_register(struct firedtv *fdtv);
+void fdtv_ca_release(struct firedtv *fdtv);
+
+/* firedtv-dvb.c */
+int fdtv_start_feed(struct dvb_demux_feed *dvbdmxfeed);
+int fdtv_stop_feed(struct dvb_demux_feed *dvbdmxfeed);
+int fdtv_dvb_register(struct firedtv *fdtv, const char *name);
+void fdtv_dvb_unregister(struct firedtv *fdtv);
+
+/* firedtv-fe.c */
+void fdtv_frontend_init(struct firedtv *fdtv, const char *name);
+
+/* firedtv-fw.c */
+int fdtv_lock(struct firedtv *fdtv, u64 addr, void *data);
+int fdtv_read(struct firedtv *fdtv, u64 addr, void *data);
+int fdtv_write(struct firedtv *fdtv, u64 addr, void *data, size_t len);
+int fdtv_start_iso(struct firedtv *fdtv);
+void fdtv_stop_iso(struct firedtv *fdtv);
+
+/* firedtv-rc.c */
+#ifdef CONFIG_DVB_FIREDTV_INPUT
+int fdtv_register_rc(struct firedtv *fdtv, struct device *dev);
+void fdtv_unregister_rc(struct firedtv *fdtv);
+void fdtv_handle_rc(struct firedtv *fdtv, unsigned int code);
+#else
+static inline int fdtv_register_rc(struct firedtv *fdtv,
+				   struct device *dev) { return 0; }
+static inline void fdtv_unregister_rc(struct firedtv *fdtv) {}
+static inline void fdtv_handle_rc(struct firedtv *fdtv, unsigned int code) {}
+#endif
+
+#endif /* _FIREDTV_H */