[tip:x86/debug] x86/kvm: Make test_cc() always inline

[tip-bot for Josh Poimboeuf]

Commit-ID:  cb7390fed4c04e609a420ac0b1c07a7a781b43bf
Gitweb:     http://git.kernel.org/tip/cb7390fed4c04e609a420ac0b1c07a7a781b43bf
Author:     Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Fri, 22 Jan 2016 10:16:12 -0600
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 24 Feb 2016 08:35:44 +0100

x86/kvm: Make test_cc() always inline

With some configs (including allyesconfig), gcc doesn't inline
test_cc().  When that happens, test_cc() doesn't create a stack frame
before inserting the inline asm call instruction.  This breaks frame
pointer convention if CONFIG_FRAME_POINTER is enabled and can result in
a bad stack trace.

Force it to always be inlined so that its containing function's stack
frame can be used.

Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Bernd Petrovitsch <bernd@xxxxxxxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Chris J Arges <chris.j.arges@xxxxxxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: Gleb Natapov <gleb@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Jiri Slaby <jslaby@xxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Marek <mmarek@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxx>
Cc: Pedro Alves <palves@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: live-patching@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20160122161612.GE20502@xxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/kvm/emulate.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index aa4d726..80363eb 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -969,7 +969,7 @@ static int em_bsr_c(struct x86_emulate_ctxt *ctxt)
 	return fastop(ctxt, em_bsr);
 }
 
-static u8 test_cc(unsigned int condition, unsigned long flags)
+static __always_inline u8 test_cc(unsigned int condition, unsigned long flags)
 {
 	u8 rc;
 	void (*fop)(void) = (void *)em_setcc + 4 * (condition & 0xf);