Re: [PATCH] gpiolib: cdev: fix frame size warning in gpio_ioctl()

From: Linus Walleij
Date: Sun Dec 27 2020 - 16:38:04 EST


On Sun, Dec 27, 2020 at 5:11 PM Kent Gibson <warthog618@xxxxxxxxx> wrote:

> The kernel test robot reports the following warning in [1]:
>
> drivers/gpio/gpiolib-cdev.c: In function 'gpio_ioctl':
> >>drivers/gpio/gpiolib-cdev.c:1437:1: warning: the frame size of 1040 bytes is larger than 1024 bytes [-Wframe-larger-than=]
>
> Refactor gpio_ioctl() to handle each ioctl in its own helper function
> and so reduce the variables stored on the stack to those explicitly
> required to service the ioctl at hand.
>
> The lineinfo_get_v1() helper handles both the GPIO_GET_LINEINFO_IOCTL
> and GPIO_GET_LINEINFO_WATCH_IOCTL, as per the corresponding v2
> implementation - lineinfo_get().
>
> [1] https://lore.kernel.org/lkml/202012270910.VW3qc1ER-lkp@xxxxxxxxx/
>
> Fixes: aad955842d1c ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Signed-off-by: Kent Gibson <warthog618@xxxxxxxxx>

That's an interesting regression.
Anyway the kernel look better after than before the patch, so
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

Bartosz will pick patches for Torvalds this kernel cycle.

Yours,
Linus Walleij