Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754488AbbGQQ5m (ORCPT ); Fri, 17 Jul 2015 12:57:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33008 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754424AbbGQQ5k (ORCPT ); Fri, 17 Jul 2015 12:57:40 -0400 From: Josh Poimboeuf To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" Cc: Michal Marek , Peter Zijlstra , Andy Lutomirski , Borislav Petkov , Linus Torvalds , Andi Kleen , Pedro Alves , x86@kernel.org, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH 11/21] x86/xen: Add xen_cpuid() and xen_setup_gdt() to stackvalidate whitelists Date: Fri, 17 Jul 2015 11:47:27 -0500 Message-Id: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1931 Lines: 59 stackvalidate reports the following false positive warnings: stackvalidate: arch/x86/xen/enlighten.o: xen_cpuid()+0x41: can't find jump dest instruction at .text+0x108 stackvalidate: arch/x86/xen/enlighten.o: xen_setup_gdt.constprop.23()+0x2e: kernel entry/exit from callable instruction The first warning is due to xen_cpuid()'s use of XEN_EMULATE_PREFIX to insert some fake instructions which stackvalidate doesn't know how to decode. The second warning is due to xen_setup_gdt()'s use of an lret instruction, which stackvalidate normally doesn't allow in callable functions. But this seems to be a valid use of the instruction. Add both functions to the stackvalidate whitelist. This results in no actual changes to the generated code. Signed-off-by: Josh Poimboeuf --- arch/x86/xen/enlighten.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 32136bf..8091836 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include @@ -345,8 +346,8 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx, *cx &= maskecx; *cx |= setecx; *dx &= maskedx; - } +STACKVALIDATE_IGNORE_FUNC(xen_cpuid); static bool __init xen_check_mwait(void) { @@ -1403,6 +1404,7 @@ static void __ref xen_setup_gdt(int cpu) pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry; pv_cpu_ops.load_gdt = xen_load_gdt; } +STACKVALIDATE_IGNORE_FUNC(xen_setup_gdt); #ifdef CONFIG_XEN_PVH /* -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/