[tip:x86/debug] x86/kvm: Add output operand in vmx_handle_external_intr inline asm

[tip-bot for Chris J Arges]

Commit-ID:  3f62de5f6f369b67b7ac709e3c942c9130d2c51a
Gitweb:     http://git.kernel.org/tip/3f62de5f6f369b67b7ac709e3c942c9130d2c51a
Author:     Chris J Arges <chris.j.arges@xxxxxxxxxxxxx>
AuthorDate: Fri, 22 Jan 2016 15:44:38 -0600
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 24 Feb 2016 08:35:44 +0100

x86/kvm: Add output operand in vmx_handle_external_intr inline asm

Stacktool generates the following warning:
  stacktool: arch/x86/kvm/vmx.o: vmx_handle_external_intr()+0x67: call without frame pointer save/setup

By adding the stackpointer as an output operand, this patch ensures that a
stack frame is created when CONFIG_FRAME_POINTER is enabled for the inline
assmebly statement.

Signed-off-by: Chris J Arges <chris.j.arges@xxxxxxxxxxxxx>
Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: gleb@xxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
Cc: live-patching@xxxxxxxxxxxxxxx
Cc: pbonzini@xxxxxxxxxx
Link: http://lkml.kernel.org/r/1453499078-9330-3-git-send-email-chris.j.arges@xxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/kvm/vmx.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e2951b6..e153522 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8356,6 +8356,7 @@ static void vmx_complete_atomic_exit(struct vcpu_vmx *vmx)
 static void vmx_handle_external_intr(struct kvm_vcpu *vcpu)
 {
 	u32 exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
+	register void *__sp asm(_ASM_SP);
 
 	/*
 	 * If external interrupt exists, IF bit is set in rflags/eflags on the
@@ -8388,8 +8389,9 @@ static void vmx_handle_external_intr(struct kvm_vcpu *vcpu)
 			"call *%[entry]\n\t"
 			:
 #ifdef CONFIG_X86_64
-			[sp]"=&r"(tmp)
+			[sp]"=&r"(tmp),
 #endif
+			"+r"(__sp)
 			:
 			[entry]"r"(entry),
 			[ss]"i"(__KERNEL_DS),