linux-kernel - [tip: x86/fpu] x86/extable: Provide EX_TYPE_DEFAULT_MCE_SAFE and EX_TYPE_FAULT_MCE

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Date:   Tue, 14 Sep 2021 19:19:34 -0000
From:   "tip-bot2 for Thomas Gleixner" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Thomas Gleixner <tglx@...utronix.de>, Borislav Petkov <bp@...e.de>,
        x86@...nel.org, linux-kernel@...r.kernel.org
Subject: [tip: x86/fpu] x86/extable: Provide EX_TYPE_DEFAULT_MCE_SAFE and
 EX_TYPE_FAULT_MCE_SAFE

The following commit has been merged into the x86/fpu branch of tip:

Commit-ID:     2cadf5248b9316d3c8af876e795d61c55476f6e9
Gitweb:        https://git.kernel.org/tip/2cadf5248b9316d3c8af876e795d61c55476f6e9
Author:        Thomas Gleixner <tglx@...utronix.de>
AuthorDate:    Wed, 08 Sep 2021 15:29:19 +02:00
Committer:     Borislav Petkov <bp@...e.de>
CommitterDate: Mon, 13 Sep 2021 17:56:56 +02:00

x86/extable: Provide EX_TYPE_DEFAULT_MCE_SAFE and EX_TYPE_FAULT_MCE_SAFE

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@...utronix.de>
Signed-off-by: Borislav Petkov <bp@...e.de>
Link: https://lkml.kernel.org/r/20210908132525.269689153@linutronix.de
---
 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 0adc117..409524d 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 74fe763..d9b77a7 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 5db46df..f37e290 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);