From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops 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 --- drivers/input/serio/maceps2.c | 204 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 204 insertions(+) create mode 100644 drivers/input/serio/maceps2.c (limited to 'drivers/input/serio/maceps2.c') diff --git a/drivers/input/serio/maceps2.c b/drivers/input/serio/maceps2.c new file mode 100644 index 000000000..fb41e7f5a --- /dev/null +++ b/drivers/input/serio/maceps2.c @@ -0,0 +1,204 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * SGI O2 MACE PS2 controller driver for linux + * + * Copyright (C) 2002 Vivien Chappelier + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +MODULE_AUTHOR("Vivien Chappelier port_data)->port; + unsigned int timeout = MACE_PS2_TIMEOUT; + + do { + if (port->status & PS2_STATUS_TX_EMPTY) { + port->tx = val; + return 0; + } + udelay(50); + } while (timeout--); + + return -1; +} + +static irqreturn_t maceps2_interrupt(int irq, void *dev_id) +{ + struct serio *dev = dev_id; + struct mace_ps2port *port = ((struct maceps2_data *)dev->port_data)->port; + unsigned long byte; + + if (port->status & PS2_STATUS_RX_FULL) { + byte = port->rx; + serio_interrupt(dev, byte & 0xff, 0); + } + + return IRQ_HANDLED; +} + +static int maceps2_open(struct serio *dev) +{ + struct maceps2_data *data = (struct maceps2_data *)dev->port_data; + + if (request_irq(data->irq, maceps2_interrupt, 0, "PS2 port", dev)) { + printk(KERN_ERR "Could not allocate PS/2 IRQ\n"); + return -EBUSY; + } + + /* Reset port */ + data->port->control = PS2_CONTROL_TX_CLOCK_DISABLE | PS2_CONTROL_RESET; + udelay(100); + + /* Enable interrupts */ + data->port->control = PS2_CONTROL_RX_CLOCK_ENABLE | + PS2_CONTROL_TX_ENABLE | + PS2_CONTROL_RX_INT_ENABLE; + + return 0; +} + +static void maceps2_close(struct serio *dev) +{ + struct maceps2_data *data = (struct maceps2_data *)dev->port_data; + + data->port->control = PS2_CONTROL_TX_CLOCK_DISABLE | PS2_CONTROL_RESET; + udelay(100); + free_irq(data->irq, dev); +} + + +static struct serio *maceps2_allocate_port(int idx) +{ + struct serio *serio; + + serio = kzalloc_obj(*serio); + if (serio) { + serio->id.type = SERIO_8042; + serio->write = maceps2_write; + serio->open = maceps2_open; + serio->close = maceps2_close; + snprintf(serio->name, sizeof(serio->name), "MACE PS/2 port%d", idx); + snprintf(serio->phys, sizeof(serio->phys), "mace/serio%d", idx); + serio->port_data = &port_data[idx]; + serio->dev.parent = &maceps2_device->dev; + } + + return serio; +} + +static int maceps2_probe(struct platform_device *dev) +{ + maceps2_port[0] = maceps2_allocate_port(0); + maceps2_port[1] = maceps2_allocate_port(1); + if (!maceps2_port[0] || !maceps2_port[1]) { + kfree(maceps2_port[0]); + kfree(maceps2_port[1]); + return -ENOMEM; + } + + serio_register_port(maceps2_port[0]); + serio_register_port(maceps2_port[1]); + + return 0; +} + +static void maceps2_remove(struct platform_device *dev) +{ + serio_unregister_port(maceps2_port[0]); + serio_unregister_port(maceps2_port[1]); +} + +static struct platform_driver maceps2_driver = { + .driver = { + .name = "maceps2", + }, + .probe = maceps2_probe, + .remove = maceps2_remove, +}; + +static int __init maceps2_init(void) +{ + int error; + + error = platform_driver_register(&maceps2_driver); + if (error) + return error; + + maceps2_device = platform_device_alloc("maceps2", -1); + if (!maceps2_device) { + error = -ENOMEM; + goto err_unregister_driver; + } + + port_data[0].port = &mace->perif.ps2.keyb; + port_data[0].irq = MACEISA_KEYB_IRQ; + port_data[1].port = &mace->perif.ps2.mouse; + port_data[1].irq = MACEISA_MOUSE_IRQ; + + error = platform_device_add(maceps2_device); + if (error) + goto err_free_device; + + return 0; + + err_free_device: + platform_device_put(maceps2_device); + err_unregister_driver: + platform_driver_unregister(&maceps2_driver); + return error; +} + +static void __exit maceps2_exit(void) +{ + platform_device_unregister(maceps2_device); + platform_driver_unregister(&maceps2_driver); +} + +module_init(maceps2_init); +module_exit(maceps2_exit); -- cgit v1.3.1