diff options
| author | Eliav Farber <farbere@amazon.com> | 2025-05-27 05:33:55 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-20 18:30:25 +0200 |
| commit | 5a96b1e9e9a5f399ece638e8e198e82a3f6b3687 (patch) | |
| tree | 63ba43270a8544718e4c10f5d1bba1cd656335dd | |
| parent | ae12c0666a076c63f9eb43f12abeedd75bc82a54 (diff) | |
pps: clients: gpio: fix interrupt handling order in remove path
[ Upstream commit 6bca1e955830808dc90e0506b2951b4256b81bbb ]
The interrupt handler in pps_gpio_probe() is registered after calling
pps_register_source() using devm_request_irq(). However, in the
corresponding remove function, pps_unregister_source() is called before
the IRQ is freed, since devm-managed resources are released after the
remove function completes.
This creates a potential race condition where an interrupt may occur
after the PPS source is unregistered but before the handler is removed,
possibly leading to a kernel panic.
To prevent this, switch from devm-managed IRQ registration to manual
management by using request_irq() and calling free_irq() explicitly in
the remove path before unregistering the PPS source. This ensures the
interrupt handler is safely removed before deactivating the PPS source.
Signed-off-by: Eliav Farber <farbere@amazon.com>
Link: https://lore.kernel.org/r/20250527053355.37185-1-farbere@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/pps/clients/pps-gpio.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c index 93e662912b53..1412f8af15f2 100644 --- a/drivers/pps/clients/pps-gpio.c +++ b/drivers/pps/clients/pps-gpio.c @@ -206,8 +206,8 @@ static int pps_gpio_probe(struct platform_device *pdev) } /* register IRQ interrupt handler */ - ret = devm_request_irq(dev, data->irq, pps_gpio_irq_handler, - get_irqf_trigger_flags(data), data->info.name, data); + ret = request_irq(data->irq, pps_gpio_irq_handler, + get_irqf_trigger_flags(data), data->info.name, data); if (ret) { pps_unregister_source(data->pps); dev_err(dev, "failed to acquire IRQ %d\n", data->irq); @@ -224,6 +224,7 @@ static void pps_gpio_remove(struct platform_device *pdev) { struct pps_gpio_device_data *data = platform_get_drvdata(pdev); + free_irq(data->irq, data); pps_unregister_source(data->pps); del_timer_sync(&data->echo_timer); /* reset echo pin in any case */ |