[PATCH v4 01/20] gpiolib: cdev: desc_to_lineinfo should set info offset

From: Kent Gibson
Date: Thu Aug 13 2020 - 23:03:27 EST


Set the value of the line info offset in desc_to_lineinfo, rather than
relying on it being passed in the info. This makes the function behave
as you would expect from the name - it generates the line info
corresponding to a given GPIO desc.

Signed-off-by: Kent Gibson <warthog618@xxxxxxxxx>
---

There are some instances where this results in the offset being set when
it is already set in the info, but I think this is clearer especially
considering that, as part of the replacement of strncpy with strscpy and
to to ensure kernel stack cannot be leaked to userspace, the info is
zeroed in a subsequent patch.

drivers/gpio/gpiolib-cdev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index e6c9b78adfc2..e95e3eab9867 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -752,6 +752,7 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
bool ok_for_pinctrl;
unsigned long flags;

+ info->line_offset = gpio_chip_hwgpio(desc);
/*
* This function takes a mutex so we must check this before taking
* the spinlock.
@@ -933,7 +934,6 @@ static int lineinfo_changed_notify(struct notifier_block *nb,
return NOTIFY_DONE;

memset(&chg, 0, sizeof(chg));
- chg.info.line_offset = gpio_chip_hwgpio(desc);
chg.event_type = action;
chg.timestamp = ktime_get_ns();
gpio_desc_to_lineinfo(desc, &chg.info);
--
2.28.0