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, 428 insertions, 0 deletions

diff --git a/drivers/media/dvb-frontends/sp2.c b/drivers/media/dvb-frontends/sp2.c
new file mode 100644
index 000000000..63dec4b4f
--- /dev/null
+++ b/drivers/media/dvb-frontends/sp2.c
@@ -0,0 +1,428 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * CIMaX SP2/SP2HF (Atmel T90FJR) CI driver
+ *
+ * Copyright (C) 2014 Olli Salonen <olli.salonen@iki.fi>
+ *
+ * Heavily based on CIMax2(R) SP2 driver in conjunction with NetUp Dual
+ * DVB-S2 CI card (cimax2) with following copyrights:
+ *
+ *  Copyright (C) 2009 NetUP Inc.
+ *  Copyright (C) 2009 Igor M. Liplianin <liplianin@netup.ru>
+ *  Copyright (C) 2009 Abylay Ospan <aospan@netup.ru>
+ */
+
+#include "sp2_priv.h"
+
+static int sp2_read_i2c(struct sp2 *s, u8 reg, u8 *buf, int len)
+{
+	int ret;
+	struct i2c_client *client = s->client;
+	struct i2c_adapter *adap = client->adapter;
+	struct i2c_msg msg[] = {
+		{
+			.addr = client->addr,
+			.flags = 0,
+			.buf = &reg,
+			.len = 1
+		}, {
+			.addr = client->addr,
+			.flags	= I2C_M_RD,
+			.buf = buf,
+			.len = len
+		}
+	};
+
+	ret = i2c_transfer(adap, msg, 2);
+
+	if (ret != 2) {
+		dev_err(&client->dev, "i2c read error, reg = 0x%02x, status = %d\n",
+				reg, ret);
+		if (ret < 0)
+			return ret;
+		else
+			return -EIO;
+	}
+
+	dev_dbg(&s->client->dev, "addr=0x%04x, reg = 0x%02x, data = %02x\n",
+				client->addr, reg, buf[0]);
+
+	return 0;
+}
+
+static int sp2_write_i2c(struct sp2 *s, u8 reg, u8 *buf, int len)
+{
+	int ret;
+	u8 buffer[35];
+	struct i2c_client *client = s->client;
+	struct i2c_adapter *adap = client->adapter;
+	struct i2c_msg msg = {
+		.addr = client->addr,
+		.flags = 0,
+		.buf = &buffer[0],
+		.len = len + 1
+	};
+
+	if ((len + 1) > sizeof(buffer)) {
+		dev_err(&client->dev, "i2c wr reg=%02x: len=%d is too big!\n",
+				reg, len);
+		return -EINVAL;
+	}
+
+	buffer[0] = reg;
+	memcpy(&buffer[1], buf, len);
+
+	ret = i2c_transfer(adap, &msg, 1);
+
+	if (ret != 1) {
+		dev_err(&client->dev, "i2c write error, reg = 0x%02x, status = %d\n",
+				reg, ret);
+		if (ret < 0)
+			return ret;
+		else
+			return -EIO;
+	}
+
+	dev_dbg(&s->client->dev, "addr=0x%04x, reg = 0x%02x, data = %*ph\n",
+				client->addr, reg, len, buf);
+
+	return 0;
+}
+
+static int sp2_ci_op_cam(struct dvb_ca_en50221 *en50221, int slot, u8 acs,
+			u8 read, int addr, u8 data)
+{
+	struct sp2 *s = en50221->data;
+	u8 store;
+	int mem, ret;
+	int (*ci_op_cam)(void*, u8, int, u8, int*) = s->ci_control;
+
+	if (slot != 0)
+		return -EINVAL;
+
+	/*
+	 * change module access type between IO space and attribute memory
+	 * when needed
+	 */
+	if (s->module_access_type != acs) {
+		ret = sp2_read_i2c(s, 0x00, &store, 1);
+
+		if (ret)
+			return ret;
+
+		store &= ~(SP2_MOD_CTL_ACS1 | SP2_MOD_CTL_ACS0);
+		store |= acs;
+
+		ret = sp2_write_i2c(s, 0x00, &store, 1);
+		if (ret)
+			return ret;
+	}
+
+	s->module_access_type = acs;
+
+	/* implementation of ci_op_cam is device specific */
+	if (ci_op_cam) {
+		ret = ci_op_cam(s->priv, read, addr, data, &mem);
+	} else {
+		dev_err(&s->client->dev, "callback not defined");
+		return -EINVAL;
+	}
+
+	if (ret)
+		return ret;
+
+	dev_dbg(&s->client->dev, "%s: slot=%d, addr=0x%04x, %s, data=%x",
+			(read) ? "read" : "write", slot, addr,
+			(acs == SP2_CI_ATTR_ACS) ? "attr" : "io",
+			(read) ? mem : data);
+
+	if (read)
+		return mem;
+	else
+		return 0;
+
+}
+
+int sp2_ci_read_attribute_mem(struct dvb_ca_en50221 *en50221,
+				int slot, int addr)
+{
+	return sp2_ci_op_cam(en50221, slot, SP2_CI_ATTR_ACS,
+			SP2_CI_RD, addr, 0);
+}
+
+int sp2_ci_write_attribute_mem(struct dvb_ca_en50221 *en50221,
+				int slot, int addr, u8 data)
+{
+	return sp2_ci_op_cam(en50221, slot, SP2_CI_ATTR_ACS,
+			SP2_CI_WR, addr, data);
+}
+
+int sp2_ci_read_cam_control(struct dvb_ca_en50221 *en50221,
+				int slot, u8 addr)
+{
+	return sp2_ci_op_cam(en50221, slot, SP2_CI_IO_ACS,
+			SP2_CI_RD, addr, 0);
+}
+
+int sp2_ci_write_cam_control(struct dvb_ca_en50221 *en50221,
+				int slot, u8 addr, u8 data)
+{
+	return sp2_ci_op_cam(en50221, slot, SP2_CI_IO_ACS,
+			SP2_CI_WR, addr, data);
+}
+
+int sp2_ci_slot_reset(struct dvb_ca_en50221 *en50221, int slot)
+{
+	struct sp2 *s = en50221->data;
+	u8 buf;
+	int ret;
+
+	dev_dbg(&s->client->dev, "slot: %d\n", slot);
+
+	if (slot != 0)
+		return -EINVAL;
+
+	/* RST on */
+	buf = SP2_MOD_CTL_RST;
+	ret = sp2_write_i2c(s, 0x00, &buf, 1);
+
+	if (ret)
+		return ret;
+
+	usleep_range(500, 600);
+
+	/* RST off */
+	buf = 0x00;
+	ret = sp2_write_i2c(s, 0x00, &buf, 1);
+
+	if (ret)
+		return ret;
+
+	msleep(1000);
+
+	return 0;
+}
+
+int sp2_ci_slot_shutdown(struct dvb_ca_en50221 *en50221, int slot)
+{
+	struct sp2 *s = en50221->data;
+
+	dev_dbg(&s->client->dev, "slot:%d\n", slot);
+
+	/* not implemented */
+	return 0;
+}
+
+int sp2_ci_slot_ts_enable(struct dvb_ca_en50221 *en50221, int slot)
+{
+	struct sp2 *s = en50221->data;
+	u8 buf;
+
+	dev_dbg(&s->client->dev, "slot:%d\n", slot);
+
+	if (slot != 0)
+		return -EINVAL;
+
+	sp2_read_i2c(s, 0x00, &buf, 1);
+
+	/* disable bypass and enable TS */
+	buf |= (SP2_MOD_CTL_TSOEN | SP2_MOD_CTL_TSIEN);
+	return sp2_write_i2c(s, 0, &buf, 1);
+}
+
+int sp2_ci_poll_slot_status(struct dvb_ca_en50221 *en50221,
+				int slot, int open)
+{
+	struct sp2 *s = en50221->data;
+	u8 buf[2];
+	int ret;
+
+	dev_dbg(&s->client->dev, "slot:%d open:%d\n", slot, open);
+
+	/*
+	 * CAM module INSERT/REMOVE processing. Slow operation because of i2c
+	 * transfers. Throttle read to one per sec.
+	 */
+	if (time_after(jiffies, s->next_status_checked_time)) {
+		ret = sp2_read_i2c(s, 0x00, buf, 1);
+		s->next_status_checked_time = jiffies +	msecs_to_jiffies(1000);
+
+		if (ret)
+			return 0;
+
+		if (buf[0] & SP2_MOD_CTL_DET)
+			s->status = DVB_CA_EN50221_POLL_CAM_PRESENT |
+					DVB_CA_EN50221_POLL_CAM_READY;
+		else
+			s->status = 0;
+	}
+
+	return s->status;
+}
+
+static int sp2_init(struct sp2 *s)
+{
+	int ret = 0;
+	u8 buf;
+	u8 cimax_init[34] = {
+		0x00, /* module A control*/
+		0x00, /* auto select mask high A */
+		0x00, /* auto select mask low A */
+		0x00, /* auto select pattern high A */
+		0x00, /* auto select pattern low A */
+		0x44, /* memory access time A, 600 ns */
+		0x00, /* invert input A */
+		0x00, /* RFU */
+		0x00, /* RFU */
+		0x00, /* module B control*/
+		0x00, /* auto select mask high B */
+		0x00, /* auto select mask low B */
+		0x00, /* auto select pattern high B */
+		0x00, /* auto select pattern low B */
+		0x44, /* memory access time B, 600 ns */
+		0x00, /* invert input B */
+		0x00, /* RFU */
+		0x00, /* RFU */
+		0x00, /* auto select mask high Ext */
+		0x00, /* auto select mask low Ext */
+		0x00, /* auto select pattern high Ext */
+		0x00, /* auto select pattern low Ext */
+		0x00, /* RFU */
+		0x02, /* destination - module A */
+		0x01, /* power control reg, VCC power on */
+		0x00, /* RFU */
+		0x00, /* int status read only */
+		0x00, /* Interrupt Mask Register */
+		0x05, /* EXTINT=active-high, INT=push-pull */
+		0x00, /* USCG1 */
+		0x04, /* ack active low */
+		0x00, /* LOCK = 0 */
+		0x22, /* unknown */
+		0x00, /* synchronization? */
+	};
+
+	dev_dbg(&s->client->dev, "\n");
+
+	s->ca.owner = THIS_MODULE;
+	s->ca.read_attribute_mem = sp2_ci_read_attribute_mem;
+	s->ca.write_attribute_mem = sp2_ci_write_attribute_mem;
+	s->ca.read_cam_control = sp2_ci_read_cam_control;
+	s->ca.write_cam_control = sp2_ci_write_cam_control;
+	s->ca.slot_reset = sp2_ci_slot_reset;
+	s->ca.slot_shutdown = sp2_ci_slot_shutdown;
+	s->ca.slot_ts_enable = sp2_ci_slot_ts_enable;
+	s->ca.poll_slot_status = sp2_ci_poll_slot_status;
+	s->ca.data = s;
+	s->module_access_type = 0;
+
+	/* initialize all regs */
+	ret = sp2_write_i2c(s, 0x00, &cimax_init[0], 34);
+	if (ret)
+		goto err;
+
+	/* lock registers */
+	buf = 1;
+	ret = sp2_write_i2c(s, 0x1f, &buf, 1);
+	if (ret)
+		goto err;
+
+	/* power on slots */
+	ret = sp2_write_i2c(s, 0x18, &buf, 1);
+	if (ret)
+		goto err;
+
+	ret = dvb_ca_en50221_init(s->dvb_adap, &s->ca, 0, 1);
+	if (ret)
+		goto err;
+
+	return 0;
+
+err:
+	dev_dbg(&s->client->dev, "init failed=%d\n", ret);
+	return ret;
+}
+
+static int sp2_exit(struct i2c_client *client)
+{
+	struct sp2 *s;
+
+	dev_dbg(&client->dev, "\n");
+
+	if (!client)
+		return 0;
+
+	s = i2c_get_clientdata(client);
+	if (!s)
+		return 0;
+
+	if (!s->ca.data)
+		return 0;
+
+	dvb_ca_en50221_release(&s->ca);
+
+	return 0;
+}
+
+static int sp2_probe(struct i2c_client *client)
+{
+	struct sp2_config *cfg = client->dev.platform_data;
+	struct sp2 *s;
+	int ret;
+
+	dev_dbg(&client->dev, "\n");
+
+	s = kzalloc_obj(*s);
+	if (!s) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	s->client = client;
+	s->dvb_adap = cfg->dvb_adap;
+	s->priv = cfg->priv;
+	s->ci_control = cfg->ci_control;
+
+	i2c_set_clientdata(client, s);
+
+	ret = sp2_init(s);
+	if (ret)
+		goto err;
+
+	dev_info(&s->client->dev, "CIMaX SP2 successfully attached\n");
+	return 0;
+err:
+	dev_dbg(&client->dev, "init failed=%d\n", ret);
+	kfree(s);
+
+	return ret;
+}
+
+static void sp2_remove(struct i2c_client *client)
+{
+	struct sp2 *s = i2c_get_clientdata(client);
+
+	dev_dbg(&client->dev, "\n");
+	sp2_exit(client);
+	kfree(s);
+}
+
+static const struct i2c_device_id sp2_id[] = {
+	{ .name = "sp2" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, sp2_id);
+
+static struct i2c_driver sp2_driver = {
+	.driver = {
+		.name	= "sp2",
+	},
+	.probe		= sp2_probe,
+	.remove		= sp2_remove,
+	.id_table	= sp2_id,
+};
+
+module_i2c_driver(sp2_driver);
+
+MODULE_DESCRIPTION("CIMaX SP2/HF CI driver");
+MODULE_AUTHOR("Olli Salonen <olli.salonen@iki.fi>");
+MODULE_LICENSE("GPL");