[PATCH v3 3/5] gpio: aggregator: Prevent collisions between DT and user device IDs

From: Andy Shevchenko
Date: Thu Jun 15 2023 - 09:51:25 EST


In case we have a device instantiated via DT or other means than
via new_device sysfs node, the collision with the latter is possible.
Prevent such collisions by allocating user instantiated devices with
higher IDs, currently set to 1024.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/gpio/gpio-aggregator.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
index 4a470dd8b75d..8892cb37ad79 100644
--- a/drivers/gpio/gpio-aggregator.c
+++ b/drivers/gpio/gpio-aggregator.c
@@ -26,6 +26,7 @@
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>

+#define AGGREGATOR_MIN_DEVID 1024
#define AGGREGATOR_MAX_GPIOS 512

/*
@@ -135,7 +136,7 @@ static ssize_t new_device_store(struct device_driver *driver, const char *buf,
}

mutex_lock(&gpio_aggregator_lock);
- id = idr_alloc(&gpio_aggregator_idr, aggr, 0, 0, GFP_KERNEL);
+ id = idr_alloc(&gpio_aggregator_idr, aggr, AGGREGATOR_MIN_DEVID, 0, GFP_KERNEL);
mutex_unlock(&gpio_aggregator_lock);

if (id < 0) {
--
2.40.0.1.gaa8946217a0b