[dm-devel] [PATCH 11/30] swsusp: don't pass a stack address to blkdev_get_by_path

[Rafael J. Wysocki]

On Thu, Jun 8, 2023 at 1:03 PM Christoph Hellwig <hch at lst.de> wrote:
>
> holder is just an on-stack pointer that can easily be reused by other calls,
> replace it with a static variable that doesn't change.
>
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> Reviewed-by: Hannes Reinecke <hare at suse.de>

Acked-by: Rafael J. Wysocki <rafael at kernel.org>

> ---
>  kernel/power/swap.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/power/swap.c b/kernel/power/swap.c
> index 81aec3b2c60510..b03ff1a33c7f68 100644
> --- a/kernel/power/swap.c
> +++ b/kernel/power/swap.c
> @@ -1510,6 +1510,8 @@ int swsusp_read(unsigned int *flags_p)
>         return error;
>  }
>
> +static void *swsusp_holder;
> +
>  /**
>   *      swsusp_check - Check for swsusp signature in the resume device
>   */
> @@ -1517,14 +1519,13 @@ int swsusp_read(unsigned int *flags_p)
>  int swsusp_check(bool snapshot_test)
>  {
>         int error;
> -       void *holder;
>         fmode_t mode = FMODE_READ;
>
>         if (snapshot_test)
>                 mode |= FMODE_EXCL;
>
>         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
> -                                           mode, &holder, NULL);
> +                                           mode, &swsusp_holder, NULL);
>         if (!IS_ERR(hib_resume_bdev)) {
>                 set_blocksize(hib_resume_bdev, PAGE_SIZE);
>                 clear_page(swsusp_header);
> --
> 2.39.2
>