[patch 6/8] x86/entry: Move irq tracing to syscall_slow_exit_work

From: Thomas Gleixner
Date: Tue Feb 25 2020 - 18:30:12 EST


which removes the ASM IRQ tracepoints.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
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: