[PATCH] Input: gpio-keys - fix crash when disabliing GPIO-less buttons
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: 2021-04-07 05:28:59
Also in:
lkml
Subsystem:
input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Dmitry Torokhov, Linus Torvalds
My brain-damaged adjustments to Paul's patch caused crashes in
gpio_keys_disable_button() when driver is used in GPIO-less (i.e.
purely interrupt-driven) setups, because I mixed together debounce and
release timers when they are in fact separate:
Unable to handle kernel NULL pointer dereference at virtual address 0000000c
...
PC is at hrtimer_active+0xc/0x98
LR is at hrtimer_try_to_cancel+0x24/0x140
...
[<c01c43b8>] (hrtimer_active) from [<c01c50f4>] (hrtimer_try_to_cancel+0x24/0x140)
[<c01c50f4>] (hrtimer_try_to_cancel) from [<c01c5224>] (hrtimer_cancel+0x14/0x4c)
[<c01c5224>] (hrtimer_cancel) from [<bf1cae24>] (gpio_keys_attr_store_helper+0x1b8/0x1d8 [gpio_keys])
[<bf1cae24>] (gpio_keys_attr_store_helper [gpio_keys]) from [<bf1cae80>] (gpio_keys_store_disabled_keys+0x18/0x24 [gpio_keys])
[<bf1cae80>] (gpio_keys_store_disabled_keys [gpio_keys]) from [<c038ec7c>] (kernfs_fop_write_iter+0x10c/0x1cc)
[<c038ec7c>] (kernfs_fop_write_iter) from [<c02df858>] (vfs_write+0x2ac/0x404)
[<c02df858>] (vfs_write) from [<c02dfaf4>] (ksys_write+0x64/0xdc)
[<c02dfaf4>] (ksys_write) from [<c0100080>] (ret_fast_syscall+0x0/0x58)
Let's fix it up.
Fixes: c9efb0ba281e ("Input: gpio-keys - use hrtimer for software debounce, if possible")
Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
Tony, could you please try this patch and see if it fixes the crash you
observed?
Thanks!
drivers/input/keyboard/gpio_keys.c | 30 +++++++++++++-----------------
1 file changed, 13 insertions(+), 17 deletions(-)
diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index fe8fc76ee22e..8dbf1e69c90a 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c@@ -125,6 +125,18 @@ static const unsigned long *get_bm_events_by_type(struct input_dev *dev, return (type == EV_KEY) ? dev->keybit : dev->swbit; } +static void gpio_keys_quiesce_key(void *data) +{ + struct gpio_button_data *bdata = data; + + if (!bdata->gpiod) + hrtimer_cancel(&bdata->release_timer); + if (bdata->debounce_use_hrtimer) + hrtimer_cancel(&bdata->debounce_timer); + else + cancel_delayed_work_sync(&bdata->work); +} + /** * gpio_keys_disable_button() - disables given GPIO button * @bdata: button data for button to be disabled
@@ -145,12 +157,7 @@ static void gpio_keys_disable_button(struct gpio_button_data *bdata) * Disable IRQ and associated timer/work structure. */ disable_irq(bdata->irq); - - if (bdata->debounce_use_hrtimer) - hrtimer_cancel(&bdata->release_timer); - else - cancel_delayed_work_sync(&bdata->work); - + gpio_keys_quiesce_key(bdata); bdata->disabled = true; } }
@@ -492,16 +499,6 @@ static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id) return IRQ_HANDLED; } -static void gpio_keys_quiesce_key(void *data) -{ - struct gpio_button_data *bdata = data; - - if (bdata->debounce_use_hrtimer) - hrtimer_cancel(&bdata->debounce_timer); - else - cancel_delayed_work_sync(&bdata->work); -} - static int gpio_keys_setup_key(struct platform_device *pdev, struct input_dev *input, struct gpio_keys_drvdata *ddata,
@@ -635,7 +632,6 @@ static int gpio_keys_setup_key(struct platform_device *pdev, } bdata->release_delay = button->debounce_interval; - bdata->debounce_use_hrtimer = true; hrtimer_init(&bdata->release_timer, CLOCK_REALTIME, HRTIMER_MODE_REL_HARD); bdata->release_timer.function = gpio_keys_irq_timer;
--
2.31.0.208.g409f899ff0-goog
--
Dmitry