From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josh Poimboeuf Subject: [PATCH v16.1 26/33] x86/kvm: Make test_cc() always inline Date: Fri, 22 Jan 2016 10:16:12 -0600 Message-ID: <20160122161612.GE20502@treble.redhat.com> References: <56A1FED2.50700@redhat.com> <20160122160245.GD20502@treble.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, Michal Marek , Peter Zijlstra , Andy Lutomirski , Borislav Petkov , Linus Torvalds , Andi Kleen , Pedro Alves , Namhyung Kim , Bernd Petrovitsch , Chris J Arges , Andrew Morton , Jiri Slaby , Arnaldo Carvalho de Melo , Gleb Natapov , kvm@vger.kernel.org To: Paolo Bonzini Return-path: Received: from mx1.redhat.com ([209.132.183.28]:52885 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752829AbcAVQQQ (ORCPT ); Fri, 22 Jan 2016 11:16:16 -0500 Content-Disposition: inline In-Reply-To: <20160122160245.GD20502@treble.redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: 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 Signed-off-by: Josh Poimboeuf Cc: Gleb Natapov Cc: kvm@vger.kernel.org --- 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); -- 2.4.3