From cadb938a5e500461d9529e9dd6e6707dfaaef616 Mon Sep 17 00:00:00 2001 From: Gaurav Kohli Date: Fri, 25 Nov 2022 22:14:51 -0800 Subject: [PATCH] x86/hyperv: Remove unregister syscore call from Hyper-V cleanup [ Upstream commit 32c97d980e2eef25465d453f2956a9ca68926a3c ] Hyper-V cleanup code comes under panic path where preemption and irq is already disabled. So calling of unregister_syscore_ops might schedule out the thread even for the case where mutex lock is free. hyperv_cleanup unregister_syscore_ops mutex_lock(&syscore_ops_lock) might_sleep Here might_sleep might schedule out this thread, where voluntary preemption config is on and this thread will never comes back. And also this was added earlier to maintain the symmetry which is not required as this can comes during crash shutdown path only. To prevent the same, removing unregister_syscore_ops function call. Signed-off-by: Gaurav Kohli Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/1669443291-2575-1-git-send-email-gauravkohli@linux.microsoft.com Signed-off-by: Wei Liu Signed-off-by: Sasha Levin --- arch/x86/hyperv/hv_init.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index 762f10c..95f98af74 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -469,8 +469,6 @@ void hyperv_cleanup(void) { union hv_x64_msr_hypercall_contents hypercall_msr; - unregister_syscore_ops(&hv_syscore_ops); - /* Reset our OS id */ wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0); -- 2.7.4