From: Tianyu Lan Tianyu.Lan@microsoft.com
[ 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@microsoft.com Signed-off-by: Tianyu Lan Tianyu.Lan@microsoft.com Link: https://lore.kernel.org/r/20200406155331.2105-3-Tianyu.Lan@microsoft.com Signed-off-by: Wei Liu wei.liu@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 5ff7c1708d0e7..dd6d18d918a4b 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1222,9 +1222,13 @@ 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); + free_page( + (unsigned long)hv_panic_page); + hv_panic_page = NULL; + } } else pr_err("Hyper-V: panic message page memory " "allocation failed"); @@ -1252,7 +1256,6 @@ 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;