[PATCH V3 2/6] x86/Hyper-V: Free hv_panic_page when fail to register kmsg dump

ltykernel
2020-03-24T07:57:33Z

From: Tianyu Lan <Tianyu.Lan@microsoft.com>

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@microsoft.com>
---
Change since v1:
- Update commit log
- Remove hv_free_hyperv_page() in the error path
---
drivers/hv/vmbus_drv.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 6478240d11ab..00a511f15926 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");
@@ -1416,7 +1420,6 @@ static int vmbus_bus_init(void)
hv_remove_vmbus_irq();

bus_unregister(&hv_bus);
- hv_free_hyperv_page((unsigned long)hv_panic_page);
unregister_sysctl_table(hv_ctl_table_hdr);
hv_ctl_table_hdr = NULL;
return ret;
--
2.14.5