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/joystick/fsia6b.c | 231 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 231 insertions(+) create mode 100644 drivers/input/joystick/fsia6b.c (limited to 'drivers/input/joystick/fsia6b.c') diff --git a/drivers/input/joystick/fsia6b.c b/drivers/input/joystick/fsia6b.c new file mode 100644 index 000000000..b0d736484 --- /dev/null +++ b/drivers/input/joystick/fsia6b.c @@ -0,0 +1,231 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * FS-iA6B iBus RC receiver driver + * + * This driver provides all 14 channels of the FlySky FS-ia6B RC receiver + * as analog values. + * + * Additionally, the channels can be converted to discrete switch values. + * By default, it is configured for the offical FS-i6 remote control. + * If you use a different hardware configuration, you can configure it + * using the `switch_config` parameter. + */ + +#include +#include +#include +#include +#include +#include +#include + +#define DRIVER_DESC "FS-iA6B iBus RC receiver" + +MODULE_AUTHOR("Markus Koch "); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL"); + +#define IBUS_SERVO_COUNT 14 + +static char *switch_config = "00000022320000"; +module_param(switch_config, charp, 0444); +MODULE_PARM_DESC(switch_config, + "Amount of switch positions per channel (14 characters, 0-3)"); + +static int fsia6b_axes[IBUS_SERVO_COUNT] = { + ABS_X, ABS_Y, + ABS_Z, ABS_RX, + ABS_RY, ABS_RZ, + ABS_HAT0X, ABS_HAT0Y, + ABS_HAT1X, ABS_HAT1Y, + ABS_HAT2X, ABS_HAT2Y, + ABS_HAT3X, ABS_HAT3Y +}; + +enum ibus_state { SYNC, COLLECT, PROCESS }; + +struct ibus_packet { + enum ibus_state state; + + int offset; + u16 ibuf; + u16 channel[IBUS_SERVO_COUNT]; +}; + +struct fsia6b { + struct input_dev *dev; + struct ibus_packet packet; + + char phys[32]; +}; + +static irqreturn_t fsia6b_serio_irq(struct serio *serio, + unsigned char data, unsigned int flags) +{ + struct fsia6b *fsia6b = serio_get_drvdata(serio); + int i; + int sw_state; + int sw_id = BTN_0; + + fsia6b->packet.ibuf = (data << 8) | ((fsia6b->packet.ibuf >> 8) & 0xFF); + + switch (fsia6b->packet.state) { + case SYNC: + if (fsia6b->packet.ibuf == 0x4020) + fsia6b->packet.state = COLLECT; + break; + + case COLLECT: + fsia6b->packet.state = PROCESS; + break; + + case PROCESS: + fsia6b->packet.channel[fsia6b->packet.offset] = + fsia6b->packet.ibuf; + fsia6b->packet.offset++; + + if (fsia6b->packet.offset == IBUS_SERVO_COUNT) { + fsia6b->packet.offset = 0; + fsia6b->packet.state = SYNC; + for (i = 0; i < IBUS_SERVO_COUNT; ++i) { + input_report_abs(fsia6b->dev, fsia6b_axes[i], + fsia6b->packet.channel[i]); + + sw_state = 0; + if (fsia6b->packet.channel[i] > 1900) + sw_state = 1; + else if (fsia6b->packet.channel[i] < 1100) + sw_state = 2; + + switch (switch_config[i]) { + case '3': + input_report_key(fsia6b->dev, + sw_id++, + sw_state == 0); + fallthrough; + case '2': + input_report_key(fsia6b->dev, + sw_id++, + sw_state == 1); + fallthrough; + case '1': + input_report_key(fsia6b->dev, + sw_id++, + sw_state == 2); + } + } + input_sync(fsia6b->dev); + } else { + fsia6b->packet.state = COLLECT; + } + break; + } + + return IRQ_HANDLED; +} + +static int fsia6b_serio_connect(struct serio *serio, struct serio_driver *drv) +{ + struct fsia6b *fsia6b; + struct input_dev *input_dev; + int err; + int i, j; + int sw_id = 0; + + fsia6b = kzalloc_obj(*fsia6b); + if (!fsia6b) + return -ENOMEM; + + fsia6b->packet.ibuf = 0; + fsia6b->packet.offset = 0; + fsia6b->packet.state = SYNC; + + serio_set_drvdata(serio, fsia6b); + + input_dev = input_allocate_device(); + if (!input_dev) { + err = -ENOMEM; + goto fail1; + } + fsia6b->dev = input_dev; + + scnprintf(fsia6b->phys, sizeof(fsia6b->phys), "%s/input0", serio->phys); + + input_dev->name = DRIVER_DESC; + input_dev->phys = fsia6b->phys; + input_dev->id.bustype = BUS_RS232; + input_dev->id.vendor = SERIO_FSIA6B; + input_dev->id.product = serio->id.id; + input_dev->id.version = 0x0100; + input_dev->dev.parent = &serio->dev; + + for (i = 0; i < IBUS_SERVO_COUNT; i++) + input_set_abs_params(input_dev, fsia6b_axes[i], + 1000, 2000, 2, 2); + + /* Register switch configuration */ + for (i = 0; i < IBUS_SERVO_COUNT; i++) { + if (switch_config[i] < '0' || switch_config[i] > '3') { + dev_err(&fsia6b->dev->dev, + "Invalid switch configuration supplied for fsia6b.\n"); + err = -EINVAL; + goto fail2; + } + + for (j = '1'; j <= switch_config[i]; j++) { + input_set_capability(input_dev, EV_KEY, BTN_0 + sw_id); + sw_id++; + } + } + + err = serio_open(serio, drv); + if (err) + goto fail2; + + err = input_register_device(fsia6b->dev); + if (err) + goto fail3; + + return 0; + +fail3: serio_close(serio); +fail2: input_free_device(input_dev); +fail1: serio_set_drvdata(serio, NULL); + kfree(fsia6b); + return err; +} + +static void fsia6b_serio_disconnect(struct serio *serio) +{ + struct fsia6b *fsia6b = serio_get_drvdata(serio); + + serio_close(serio); + serio_set_drvdata(serio, NULL); + input_unregister_device(fsia6b->dev); + kfree(fsia6b); +} + +static const struct serio_device_id fsia6b_serio_ids[] = { + { + .type = SERIO_RS232, + .proto = SERIO_FSIA6B, + .id = SERIO_ANY, + .extra = SERIO_ANY, + }, + { 0 } +}; + +MODULE_DEVICE_TABLE(serio, fsia6b_serio_ids); + +static struct serio_driver fsia6b_serio_drv = { + .driver = { + .name = "fsia6b" + }, + .description = DRIVER_DESC, + .id_table = fsia6b_serio_ids, + .interrupt = fsia6b_serio_irq, + .connect = fsia6b_serio_connect, + .disconnect = fsia6b_serio_disconnect +}; + +module_serio_driver(fsia6b_serio_drv) -- cgit v1.3.1