[patch V2.1 09/20] x86/extable: Remove EX_TYPE_FAULT from MCE safe fixups

From: Thomas Gleixner
Date: Tue Sep 07 2021 - 16:25:20 EST


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@xxxxxxxxxx

The code relies on the trap number being stored if ENCLS raised an
exception. That's still working, but it does not longer trick the MCE code
to assume that #MC is handled correctly for ENCLS.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
V2: New patch
---
arch/x86/kernel/cpu/mce/severity.c | 1 -
1 file changed, 1 deletion(-)

--- 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,
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;