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/mouse/rpcmouse.c | 113 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 113 insertions(+) create mode 100644 drivers/input/mouse/rpcmouse.c (limited to 'drivers/input/mouse/rpcmouse.c') diff --git a/drivers/input/mouse/rpcmouse.c b/drivers/input/mouse/rpcmouse.c new file mode 100644 index 000000000..6774029e0 --- /dev/null +++ b/drivers/input/mouse/rpcmouse.c @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Acorn RiscPC mouse driver for Linux/ARM + * + * Copyright (c) 2000-2002 Vojtech Pavlik + * Copyright (C) 1996-2002 Russell King + */ + +/* + * + * This handles the Acorn RiscPCs mouse. We basically have a couple of + * hardware registers that track the sensor count for the X-Y movement and + * another register holding the button state. On every VSYNC interrupt we read + * the complete state and then work out if something has changed. + */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +MODULE_AUTHOR("Vojtech Pavlik, Russell King"); +MODULE_DESCRIPTION("Acorn RiscPC mouse driver"); +MODULE_LICENSE("GPL"); + +static short rpcmouse_lastx, rpcmouse_lasty; +static struct input_dev *rpcmouse_dev; + +static irqreturn_t rpcmouse_irq(int irq, void *dev_id) +{ + struct input_dev *dev = dev_id; + short x, y, dx, dy, b; + + x = (short) iomd_readl(IOMD_MOUSEX); + y = (short) iomd_readl(IOMD_MOUSEY); + b = (short) (__raw_readl(IOMEM(0xe0310000)) ^ 0x70); + + dx = x - rpcmouse_lastx; + dy = y - rpcmouse_lasty; + + rpcmouse_lastx = x; + rpcmouse_lasty = y; + + input_report_rel(dev, REL_X, dx); + input_report_rel(dev, REL_Y, -dy); + + input_report_key(dev, BTN_LEFT, b & 0x40); + input_report_key(dev, BTN_MIDDLE, b & 0x20); + input_report_key(dev, BTN_RIGHT, b & 0x10); + + input_sync(dev); + + return IRQ_HANDLED; +} + + +static int __init rpcmouse_init(void) +{ + int err; + + rpcmouse_dev = input_allocate_device(); + if (!rpcmouse_dev) + return -ENOMEM; + + rpcmouse_dev->name = "Acorn RiscPC Mouse"; + rpcmouse_dev->phys = "rpcmouse/input0"; + rpcmouse_dev->id.bustype = BUS_HOST; + rpcmouse_dev->id.vendor = 0x0005; + rpcmouse_dev->id.product = 0x0001; + rpcmouse_dev->id.version = 0x0100; + + rpcmouse_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL); + rpcmouse_dev->keybit[BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) | + BIT_MASK(BTN_MIDDLE) | BIT_MASK(BTN_RIGHT); + rpcmouse_dev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y); + + rpcmouse_lastx = (short) iomd_readl(IOMD_MOUSEX); + rpcmouse_lasty = (short) iomd_readl(IOMD_MOUSEY); + + if (request_irq(IRQ_VSYNCPULSE, rpcmouse_irq, IRQF_SHARED, "rpcmouse", rpcmouse_dev)) { + printk(KERN_ERR "rpcmouse: unable to allocate VSYNC interrupt\n"); + err = -EBUSY; + goto err_free_dev; + } + + err = input_register_device(rpcmouse_dev); + if (err) + goto err_free_irq; + + return 0; + + err_free_irq: + free_irq(IRQ_VSYNCPULSE, rpcmouse_dev); + err_free_dev: + input_free_device(rpcmouse_dev); + + return err; +} + +static void __exit rpcmouse_exit(void) +{ + free_irq(IRQ_VSYNCPULSE, rpcmouse_dev); + input_unregister_device(rpcmouse_dev); +} + +module_init(rpcmouse_init); +module_exit(rpcmouse_exit); -- cgit v1.3.1