linux-kernel - [patch 16/16] x86/entry: Disable interrupts in IDTENTRY

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Date:   Tue, 25 Feb 2020 23:33:37 +0100
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     x86@...nel.org, Steven Rostedt <rostedt@...dmis.org>,
        Brian Gerst <brgerst@...il.com>,
        Juergen Gross <jgross@...e.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Arnd Bergmann <arnd@...db.de>
Subject: [patch 16/16] x86/entry: Disable interrupts in IDTENTRY

Not all exceptions guarantee to return with interrupts disabled. Disable
them in idtentry_exit() which is invoked on all regular (non IST) exception
entry points. Preparatory patch for further consolidation of the return
code.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
 arch/x86/entry/entry_64.S       |    3 +--
 arch/x86/include/asm/idtentry.h |    3 ++-
 2 files changed, 3 insertions(+), 3 deletions(-)

--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1336,8 +1336,7 @@ SYM_CODE_END(error_entry)
 
 SYM_CODE_START_LOCAL(error_exit)
 	UNWIND_HINT_REGS
-	DISABLE_INTERRUPTS(CLBR_ANY)
-	TRACE_IRQS_OFF
+	DEBUG_ENTRY_ASSERT_IRQS_OFF
 	testb	$3, CS(%rsp)
 	jz	retint_kernel
 	jmp	.Lretint_user
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -37,10 +37,11 @@ static __always_inline void idtentry_ent
 /**
  * idtentry_exit - Prepare returning to low level ASM code
  *
- * Place holder for now.
+ * Disables interrupts before returning
  */
 static __always_inline void idtentry_exit(struct pt_regs *regs)
 {
+	local_irq_disable();
 }
 
 /**