Commit 89b0b47a authored Apr 06, 2020 by Tianyu Lan Committed by Greg Kroah-Hartman Apr 23, 2020

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: 81b18bce ("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>

parent 5e059fc0

drivers/hv/vmbus_drv.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -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;