From: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
[ Upstream commit 7f11a2cc10a4ae3a70e2c73361f4a9a33503539b ]
If kmsg_dump_register() fails, hv_panic_page will not be used
anywhere. So free and reset it.
Fixes: 81b18bce48af ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic")
Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Signed-off-by: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200406155331.2105-3-Tianyu.Lan@xxxxxxxxxxxxx
Signed-off-by: Wei Liu <wei.liu@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 593107c20e977..40f6b73dae940 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1401,9 +1401,13 @@ static int vmbus_bus_init(void)
hv_panic_page = (void *)get_zeroed_page(GFP_KERNEL);
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");
@@ -1433,7 +1437,6 @@ static int vmbus_bus_init(void)
hv_remove_vmbus_irq();
bus_unregister(&hv_bus);
- free_page((unsigned long)hv_panic_page);
unregister_sysctl_table(hv_ctl_table_hdr);
hv_ctl_table_hdr = NULL;
return ret;
--
2.20.1
