[PATCH 5.15 145/201] x86/extable: Provide EX_TYPE_DEFAULT_MCE_SAFE and EX_TYPE_FAULT_MCE_SAFE

Greg Kroah-Hartman
2022-07-27T17:22:20Z

From: Thomas Gleixner <tglx@linutronix.de>

[ Upstream commit 2cadf5248b9316d3c8af876e795d61c55476f6e9 ]

Provide exception fixup types which can be used to identify fixups which
allow in kernel #MC recovery and make them invoke the existing handlers.

These will be used at places where #MC recovery is handled correctly by the
caller.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210908132525.269689153@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/include/asm/extable_fixup_types.h | 3 +++
arch/x86/kernel/cpu/mce/severity.c | 2 ++
arch/x86/mm/extable.c | 2 ++
3 files changed, 7 insertions(+)

diff --git a/arch/x86/include/asm/extable_fixup_types.h b/arch/x86/include/asm/extable_fixup_types.h
index 0adc117618e6..409524d5d2eb 100644
--- a/arch/x86/include/asm/extable_fixup_types.h
+++ b/arch/x86/include/asm/extable_fixup_types.h
@@ -16,4 +16,7 @@
#define EX_TYPE_WRMSR_IN_MCE 10
#define EX_TYPE_RDMSR_IN_MCE 11

+#define EX_TYPE_DEFAULT_MCE_SAFE 12
+#define EX_TYPE_FAULT_MCE_SAFE 13
+
#endif
diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/severity.c
index 74fe763bffda..d9b77a74f8d2 100644
--- a/arch/x86/kernel/cpu/mce/severity.c
+++ b/arch/x86/kernel/cpu/mce/severity.c
@@ -278,6 +278,8 @@ static int error_context(struct mce *m, struct pt_regs *regs)
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;
return IN_KERNEL_RECOV;
default:
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index 5db46df409b5..f37e290e6d0a 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -131,8 +131,10 @@ int fixup_exception(struct pt_regs *regs, int trapnr, unsigned long error_code,

switch (e->type) {
case EX_TYPE_DEFAULT:
+ case EX_TYPE_DEFAULT_MCE_SAFE:
return ex_handler_default(e, regs);
case EX_TYPE_FAULT:
+ case EX_TYPE_FAULT_MCE_SAFE:
return ex_handler_fault(e, regs, trapnr);
case EX_TYPE_UACCESS:
return ex_handler_uaccess(e, regs, trapnr);
--
2.35.1