x86/Hyper-V: Free hv_panic_page when fail to register kmsg dump

[ Upstream commit 7f11a2cc10a4ae3a70e2c73361f4a9a33503539b ]

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

Fixes: 81b18bce48 ("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>
This commit is contained in:
Tianyu Lan 2020-04-06 08:53:27 -07:00 committed by Greg Kroah-Hartman
parent d662b44161
commit 94ebb1eea0

View File

@ -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 @@ err_alloc:
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;