linux-kernel - [PATCH 05/10] x86/tracing: Remove redundant trace_pagefault

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Message-Id: <83a77ecc56ba514c2d1f966c0e3ca97bdfe7e755.1741708239.git.namcao@linutronix.de>
Date: Tue, 11 Mar 2025 18:05:06 +0100
From: Nam Cao <namcao@...utronix.de>
To: Steven Rostedt <rostedt@...dmis.org>,
	Gabriele Monaco <gmonaco@...hat.com>,
	john.ogness@...utronix.de,
	linux-trace-kernel@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc: Nam Cao <namcao@...utronix.de>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	x86@...nel.org,
	"H . Peter Anvin" <hpa@...or.com>,
	Andy Lutomirski <luto@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>
Subject: [PATCH 05/10] x86/tracing: Remove redundant trace_pagefault_key

trace_pagefault_key is used to determine whether the tracepoints are
registered and whether to call trace functions. However, tracepoints
already have this functionality built-in.

Remove this redundant key.

Signed-off-by: Nam Cao <namcao@...utronix.de>
---
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: x86@...nel.org
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Peter Zijlstra <peterz@...radead.org>
---
 arch/x86/include/asm/trace/common.h      | 12 ------------
 arch/x86/include/asm/trace/exceptions.h  | 18 ++++++------------
 arch/x86/include/asm/trace/irq_vectors.h |  1 -
 arch/x86/kernel/tracepoint.c             | 21 ---------------------
 arch/x86/mm/fault.c                      |  3 ---
 5 files changed, 6 insertions(+), 49 deletions(-)
 delete mode 100644 arch/x86/include/asm/trace/common.h
 delete mode 100644 arch/x86/kernel/tracepoint.c

diff --git a/arch/x86/include/asm/trace/common.h b/arch/x86/include/asm/trace/common.h
deleted file mode 100644
index f0f9bcdb74d9..000000000000
--- a/arch/x86/include/asm/trace/common.h
+++ /dev/null
@@ -1,12 +0,0 @@
-#ifndef _ASM_TRACE_COMMON_H
-#define _ASM_TRACE_COMMON_H
-
-#ifdef CONFIG_TRACING
-DECLARE_STATIC_KEY_FALSE(trace_pagefault_key);
-#define trace_pagefault_enabled()			\
-	static_branch_unlikely(&trace_pagefault_key)
-#else
-static inline bool trace_pagefault_enabled(void) { return false; }
-#endif
-
-#endif
diff --git a/arch/x86/include/asm/trace/exceptions.h b/arch/x86/include/asm/trace/exceptions.h
index 6b1e87194809..34bc8214a2d7 100644
--- a/arch/x86/include/asm/trace/exceptions.h
+++ b/arch/x86/include/asm/trace/exceptions.h
@@ -6,10 +6,6 @@
 #define _TRACE_PAGE_FAULT_H
 
 #include <linux/tracepoint.h>
-#include <asm/trace/common.h>
-
-extern int trace_pagefault_reg(void);
-extern void trace_pagefault_unreg(void);
 
 DECLARE_EVENT_CLASS(x86_exceptions,
 
@@ -34,15 +30,13 @@ DECLARE_EVENT_CLASS(x86_exceptions,
 		  (void *)__entry->address, (void *)__entry->ip,
 		  __entry->error_code) );
 
-#define DEFINE_PAGE_FAULT_EVENT(name)				\
-DEFINE_EVENT_FN(x86_exceptions, name,				\
-	TP_PROTO(unsigned long address,	struct pt_regs *regs,	\
-		 unsigned long error_code),			\
-	TP_ARGS(address, regs, error_code),			\
-	trace_pagefault_reg, trace_pagefault_unreg);
+DEFINE_EVENT(x86_exceptions, page_fault_user,
+	TP_PROTO(unsigned long address,	struct pt_regs *regs, unsigned long error_code),
+	TP_ARGS(address, regs, error_code));
 
-DEFINE_PAGE_FAULT_EVENT(page_fault_user);
-DEFINE_PAGE_FAULT_EVENT(page_fault_kernel);
+DEFINE_EVENT(x86_exceptions, page_fault_kernel,
+	TP_PROTO(unsigned long address,	struct pt_regs *regs, unsigned long error_code),
+	TP_ARGS(address, regs, error_code));
 
 #undef TRACE_INCLUDE_PATH
 #undef TRACE_INCLUDE_FILE
diff --git a/arch/x86/include/asm/trace/irq_vectors.h b/arch/x86/include/asm/trace/irq_vectors.h
index 88e7f0f3bf62..7408bebdfde0 100644
--- a/arch/x86/include/asm/trace/irq_vectors.h
+++ b/arch/x86/include/asm/trace/irq_vectors.h
@@ -6,7 +6,6 @@
 #define _TRACE_IRQ_VECTORS_H
 
 #include <linux/tracepoint.h>
-#include <asm/trace/common.h>
 
 #ifdef CONFIG_X86_LOCAL_APIC
 
diff --git a/arch/x86/kernel/tracepoint.c b/arch/x86/kernel/tracepoint.c
deleted file mode 100644
index 03ae1caaa878..000000000000
--- a/arch/x86/kernel/tracepoint.c
+++ /dev/null
@@ -1,21 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (C) 2013 Seiji Aguchi <seiji.aguchi@....com>
- */
-#include <linux/jump_label.h>
-#include <linux/atomic.h>
-
-#include <asm/trace/exceptions.h>
-
-DEFINE_STATIC_KEY_FALSE(trace_pagefault_key);
-
-int trace_pagefault_reg(void)
-{
-	static_branch_inc(&trace_pagefault_key);
-	return 0;
-}
-
-void trace_pagefault_unreg(void)
-{
-	static_branch_dec(&trace_pagefault_key);
-}
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 296d294142c8..7e3e51fa1f95 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1455,9 +1455,6 @@ static __always_inline void
 trace_page_fault_entries(struct pt_regs *regs, unsigned long error_code,
 			 unsigned long address)
 {
-	if (!trace_pagefault_enabled())
-		return;
-
 	if (user_mode(regs))
 		trace_page_fault_user(address, regs, error_code);
 	else
-- 
2.39.5