[RESEND,V3,16/23] x86/entry/64: Mark ___preempt_schedule_notrace() thunk noinstr

Commit Message

Thomas Gleixner March 20, 2020, 6 p.m. UTC

Code calling this from noinstr sections, e.g. entry code, has interrupts
disabled, so the actual call into the scheduler code does not happen.

The objtool section check complains nevertheless, so mark the call "safe".

Signed-off-by: Thomas Gleixner <[e-mail]>
---
 arch/x86/entry/thunk_64.S |   18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

Patch

--- a/arch/x86/entry/thunk_64.S
+++ b/arch/x86/entry/thunk_64.S
@@ -49,7 +49,22 @@  SYM_FUNC_START_NOALIGN(\name)
 	movq 8(%rbp), %rdi
 	.endif
 
+	.if \check_if
+1:
+	.pushsection .discard.instr_begin
+	.long 1b - .
+	.popsection
+
+	call \func
+2:
+	.pushsection .discard.instr_end
+	.long 2b - .
+	.popsection
+
+	.else
 	call \func
+	.endif
+
 	jmp  .L_restore
 SYM_FUNC_END(\name)
 	_ASM_NOKPROBE(\name)
@@ -68,13 +83,16 @@  SYM_FUNC_END(\name)
 	THUNK ___preempt_schedule, preempt_schedule
 	EXPORT_SYMBOL(___preempt_schedule)
 
+.pushsection .noinstr.text, "ax"
 	THUNK ___preempt_schedule_notrace, preempt_schedule_notrace, check_if=1
+.popsection
 	EXPORT_SYMBOL(___preempt_schedule_notrace)
 #endif
 
 #if defined(CONFIG_TRACE_IRQFLAGS) \
  || defined(CONFIG_DEBUG_LOCK_ALLOC) \
  || defined(CONFIG_PREEMPTION)
+.section .noinstr.text, "ax"
 SYM_CODE_START_LOCAL_NOALIGN(.L_restore)
 	popq %r11
 	popq %r10