linux-kernel - [tip: x86/entry] x86/apic: Split out spurious handling code

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Date:   Thu, 11 Feb 2021 00:50:26 -0000
From:   "tip-bot2 for Thomas Gleixner" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Kees Cook <keescook@...omium.org>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: x86/entry] x86/apic: Split out spurious handling code

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

Commit-ID:     3c5e0267ec3e6ed7d3f1793273cbf0beb4f86a74
Gitweb:        https://git.kernel.org/tip/3c5e0267ec3e6ed7d3f1793273cbf0beb4f86a74
Author:        Thomas Gleixner <tglx@...utronix.de>
AuthorDate:    Wed, 10 Feb 2021 00:40:45 +01:00
Committer:     Thomas Gleixner <tglx@...utronix.de>
CommitterDate: Wed, 10 Feb 2021 23:34:14 +01:00

x86/apic: Split out spurious handling code

sysvec_spurious_apic_interrupt() calls into the handling body of
__spurious_interrupt() which is not obvious as that function is declared
inside the DEFINE_IDTENTRY_IRQ(spurious_interrupt) macro.

As __spurious_interrupt() is currently always inlined this ends up with two
copies of the same code for no reason.

Split the handling function out and invoke it from both entry points.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Reviewed-by: Kees Cook <keescook@...omium.org>
Link: https://lore.kernel.org/r/20210210002512.469379641@linutronix.de


---
 arch/x86/kernel/apic/apic.c | 31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 6bd20c0..02956c0 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -2133,18 +2133,11 @@ void __init register_lapic_address(unsigned long address)
  * Local APIC interrupts
  */
 
-/**
- * spurious_interrupt - Catch all for interrupts raised on unused vectors
- * @regs:	Pointer to pt_regs on stack
- * @vector:	The vector number
- *
- * This is invoked from ASM entry code to catch all interrupts which
- * trigger on an entry which is routed to the common_spurious idtentry
- * point.
- *
- * Also called from sysvec_spurious_apic_interrupt().
+/*
+ * Common handling code for spurious_interrupt and spurious_vector entry
+ * points below. No point in allowing the compiler to inline it twice.
  */
-DEFINE_IDTENTRY_IRQ(spurious_interrupt)
+static noinline void handle_spurious_interrupt(u8 vector)
 {
 	u32 v;
 
@@ -2179,9 +2172,23 @@ out:
 	trace_spurious_apic_exit(vector);
 }
 
+/**
+ * spurious_interrupt - Catch all for interrupts raised on unused vectors
+ * @regs:	Pointer to pt_regs on stack
+ * @vector:	The vector number
+ *
+ * This is invoked from ASM entry code to catch all interrupts which
+ * trigger on an entry which is routed to the common_spurious idtentry
+ * point.
+ */
+DEFINE_IDTENTRY_IRQ(spurious_interrupt)
+{
+	handle_spurious_interrupt(vector);
+}
+
 DEFINE_IDTENTRY_SYSVEC(sysvec_spurious_apic_interrupt)
 {
-	__spurious_interrupt(regs, SPURIOUS_APIC_VECTOR);
+	handle_spurious_interrupt(SPURIOUS_APIC_VECTOR);
 }
 
 /*