From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 8 Sep 2021 15:29:24 +0200
Subject: x86/extable: Remove EX_TYPE_FAULT from MCE safe fixups
Git-commit: 0c2e62ba04cd0b7194b380bae4fc35c45bb2e46e
Patch-mainline: v5.15 or v5.15-rc8 (next release)
References: jsc#SLE-18931

Now that the MC safe copy and FPU have been converted to use the MCE safe
fixup types remove EX_TYPE_FAULT from the list of types which MCE considers
to be safe to be recovered in kernel.

This removes the SGX exception handling of ENCLS from the #MC safe
handling, but according to the SGX wizards the current SGX implementations
cannot survive #MC on ENCLS:

  https://lore.kernel.org/r/YS+upEmTfpZub3s9@google.com

The code relies on the trap number being stored if ENCLS raised an
exception. That's still working, but it does no longer trick the MCE code
into assuming that #MC is handled correctly for ENCLS.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210908132525.445255957@linutronix.de
---
 arch/x86/kernel/cpu/mce/severity.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/severity.c
index d9b77a74f8d2..f60bbaff9f65 100644
--- a/arch/x86/kernel/cpu/mce/severity.c
+++ b/arch/x86/kernel/cpu/mce/severity.c
@@ -277,7 +277,6 @@ static int error_context(struct mce *m, struct pt_regs *regs)
 			return IN_KERNEL;
 		m->kflags |= MCE_IN_KERNEL_COPYIN;
 		fallthrough;
-	case EX_TYPE_FAULT:
 	case EX_TYPE_FAULT_MCE_SAFE:
 	case EX_TYPE_DEFAULT_MCE_SAFE:
 		m->kflags |= MCE_IN_KERNEL_RECOV;