RE: [PATCH 2/4] x86/Hyper-V: Free hv_panic_page when fail to register kmsg dump

From: Michael Kelley
Date: Wed Mar 18 2020 - 20:38:13 EST


From: ltykernel@xxxxxxxxx <ltykernel@xxxxxxxxx> Sent: Tuesday, March 17, 2020 6:25 AM
>
> If fail to register kmsg dump on Hyper-V platform, hv_panic_page
> will not be used anywhere. So free and reset it.

Slight commit message wording cleanup:

If kmsg_dump_register() fails, hv_panic_page will not be used
anywhere. So free and reset it.

>
> Signed-off-by: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
> ---
> drivers/hv/vmbus_drv.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
> index b56b9fb9bd90..b043efea092a 100644
> --- a/drivers/hv/vmbus_drv.c
> +++ b/drivers/hv/vmbus_drv.c
> @@ -1385,9 +1385,13 @@ static int vmbus_bus_init(void)
> hv_panic_page = (void *)hv_alloc_hyperv_zeroed_page();
> if (hv_panic_page) {
> ret = kmsg_dump_register(&hv_kmsg_dumper);
> - if (ret)
> + if (ret) {
> pr_err("Hyper-V: kmsg dump register "
> "error 0x%x\n", ret);
> + hv_free_hyperv_page(
> + (unsigned long)hv_panic_page);
> + hv_panic_page = NULL;
> + }
> } else
> pr_err("Hyper-V: panic message page memory "
> "allocation failed");
> --
> 2.14.5