Commit 1641b9b0 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86-irq-2023-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 irq fix from Ingo Molnar:
 "Fix out-of-order NMI nesting checks resulting in false positive
  warnings"

* tag 'x86-irq-2023-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/nmi: Fix out-of-order NMI nesting checks & false positive warning
parents ed766c26 f44075ec

arch/x86/kernel/nmi.c

+7 −6
Original line number Diff line number Diff line
@@ -507,12 +507,13 @@ DEFINE_IDTENTRY_RAW(exc_nmi) 
	}

	this_cpu_write(nmi_state, NMI_EXECUTING);

	this_cpu_write(nmi_cr2, read_cr2());



nmi_restart:

	if (IS_ENABLED(CONFIG_NMI_CHECK_CPU)) {

		WRITE_ONCE(nsp->idt_seq, nsp->idt_seq + 1);

		WARN_ON_ONCE(!(nsp->idt_seq & 0x1));

		WRITE_ONCE(nsp->recv_jiffies, jiffies);

	}

nmi_restart:



	/*

	 * Needs to happen before DR7 is accessed, because the hypervisor can
@@ -548,16 +549,16 @@ DEFINE_IDTENTRY_RAW(exc_nmi) 


	if (unlikely(this_cpu_read(nmi_cr2) != read_cr2()))

		write_cr2(this_cpu_read(nmi_cr2));

	if (this_cpu_dec_return(nmi_state))

		goto nmi_restart;



	if (user_mode(regs))

		mds_user_clear_cpu_buffers();

	if (IS_ENABLED(CONFIG_NMI_CHECK_CPU)) {

		WRITE_ONCE(nsp->idt_seq, nsp->idt_seq + 1);

		WARN_ON_ONCE(nsp->idt_seq & 0x1);

		WRITE_ONCE(nsp->recv_jiffies, jiffies);

	}

	if (this_cpu_dec_return(nmi_state))

		goto nmi_restart;



	if (user_mode(regs))

		mds_user_clear_cpu_buffers();

}



#if IS_ENABLED(CONFIG_KVM_INTEL)