Re: [PATCH] virt: sev-guest: Mark driver struct with __refdata to prevent section mismatch

Kuppuswamy Sathyanarayanan
2024-03-30T00:16:13Z

On 3/29/24 2:54 PM, Uwe Kleine-König wrote:
> As described in the added code comment, a reference to .exit.text is ok
> for drivers registered via module_platform_driver_probe(). Make this
> explicit to prevent the following section mismatch warning
>
> WARNING: modpost: drivers/virt/coco/sev-guest/sev-guest: section mismatch in reference: sev_guest_driver+0x10 (section: .data) -> sev_guest_remove (section: .exit.text)
>
> that triggers on an allmodconfig W=1 build.
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---

LGTM

Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> drivers/virt/coco/sev-guest/sev-guest.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
> index 87f241825bc3..1af68065b3d9 100644
> --- a/drivers/virt/coco/sev-guest/sev-guest.c
> +++ b/drivers/virt/coco/sev-guest/sev-guest.c
> @@ -1009,8 +1009,13 @@ static void __exit sev_guest_remove(struct platform_device *pdev)
> * This driver is meant to be a common SEV guest interface driver and to
> * support any SEV guest API. As such, even though it has been introduced
> * with the SEV-SNP support, it is named "sev-guest".
> + *
> + * sev_guest_remove() lives in .exit.text. For drivers registered via
> + * module_platform_driver_probe() this is ok because they cannot get unbound at
> + * runtime. So mark the driver struct with __refdata to prevent modpost
> + * triggering a section mismatch warning.
> */
> -static struct platform_driver sev_guest_driver = {
> +static struct platform_driver sev_guest_driver __refdata = {
> .remove_new = __exit_p(sev_guest_remove),
> .driver = {
> .name = "sev-guest",
> base-commit: a6bd6c9333397f5a0e2667d4d82fef8c970108f2

--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer