linux-kernel - [patch 6/8] x86/entry: Move irq tracing to syscall_slow_exit

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Message-Id: <20200225221305.813084267@linutronix.de>
Date:   Tue, 25 Feb 2020 23:08:07 +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 6/8] x86/entry: Move irq tracing to syscall_slow_exit_work

which removes the ASM IRQ tracepoints.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
 arch/x86/entry/common.c   |    2 ++
 arch/x86/entry/entry_32.S |    3 ++-
 arch/x86/entry/entry_64.S |    3 ---
 3 files changed, 4 insertions(+), 4 deletions(-)

--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -299,6 +299,8 @@ static void syscall_slow_exit_work(struc
 
 	local_irq_disable();
 	__prepare_exit_to_usermode(regs);
+	/* Return to user space enables interrupts */
+	trace_hardirqs_on();
 }
 NOKPROBE_SYMBOL(syscall_return_slowpath);
 
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -812,7 +812,7 @@ SYM_CODE_START(ret_from_fork)
 	movl    %esp, %eax
 	call    syscall_return_slowpath
 	STACKLEAK_ERASE
-	jmp     restore_all
+	jmp     restore_all_switch_stack
 
 	/* kernel thread */
 1:	movl	%edi, %eax
@@ -1077,6 +1077,7 @@ SYM_FUNC_START(entry_INT80_32)
 
 restore_all:
 	TRACE_IRQS_IRET
+restore_all_switch_stack:
 	SWITCH_TO_ENTRY_STACK
 	CHECK_AND_APPLY_ESPFIX
 .Lrestore_nocheck:
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -172,8 +172,6 @@ SYM_INNER_LABEL(entry_SYSCALL_64_after_h
 	movq	%rsp, %rsi
 	call	do_syscall_64		/* returns with IRQs disabled */
 
-	TRACE_IRQS_ON			/* return enables interrupts */
-
 	/*
 	 * Try to use SYSRET instead of IRET if we're returning to
 	 * a completely clean 64-bit userspace context.  If we're not,
@@ -340,7 +338,6 @@ SYM_CODE_START(ret_from_fork)
 	UNWIND_HINT_REGS
 	movq	%rsp, %rdi
 	call	syscall_return_slowpath	/* returns with IRQs disabled */
-	TRACE_IRQS_ON			/* user mode is traced as IRQS on */
 	jmp	swapgs_restore_regs_and_return_to_usermode
 
 1: