Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752503AbbBXMxR (ORCPT ); Tue, 24 Feb 2015 07:53:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39731 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750850AbbBXMxP (ORCPT ); Tue, 24 Feb 2015 07:53:15 -0500 From: Denys Vlasenko To: Andy Lutomirski Cc: Denys Vlasenko , Linus Torvalds , Oleg Nesterov , Borislav Petkov , "H. Peter Anvin" , Frederic Weisbecker , X86 ML , Alexei Starovoitov , Will Drewry , Kees Cook , Steven Rostedt , linux-kernel@vger.kernel.org Subject: [PATCH 4/6 v2] x86: entry_64.S: fold test_in_nmi macro into its only user Date: Tue, 24 Feb 2015 13:52:38 +0100 Message-Id: <1424782358-23816-1-git-send-email-dvlasenk@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2446 Lines: 84 No code changes. Changes since v1: added comments as requested by Steven Rostedt Signed-off-by: Denys Vlasenko CC: Linus Torvalds CC: Oleg Nesterov CC: Borislav Petkov CC: "H. Peter Anvin" CC: Andy Lutomirski CC: Frederic Weisbecker CC: X86 ML CC: Alexei Starovoitov CC: Will Drewry CC: Kees Cook CC: Steven Rostedt CC: linux-kernel@vger.kernel.org --- arch/x86/kernel/entry_64.S | 30 ++++++++++++++---------------- 1 file changed, 14 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 03498d0..0ec7928 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -1378,19 +1378,7 @@ ENTRY(error_exit) CFI_ENDPROC END(error_exit) -/* - * Test if a given stack is an NMI stack or not. - */ - .macro test_in_nmi reg stack nmi_ret normal_ret - cmpq %\reg, \stack - ja \normal_ret - subq $EXCEPTION_STKSZ, %\reg - cmpq %\reg, \stack - jb \normal_ret - jmp \nmi_ret - .endm - - /* runs on exception stack */ +/* Runs on exception stack */ ENTRY(nmi) INTR_FRAME PARAVIRT_ADJUST_EXCEPTION_FRAME @@ -1426,7 +1414,7 @@ ENTRY(nmi) * NMI. */ - /* Use %rdx as out temp variable throughout */ + /* Use %rdx as our temp variable throughout */ pushq_cfi %rdx CFI_REL_OFFSET rdx, 0 @@ -1451,8 +1439,18 @@ ENTRY(nmi) * We check the variable because the first NMI could be in a * breakpoint routine using a breakpoint stack. */ - lea 6*8(%rsp), %rdx - test_in_nmi rdx, 4*8(%rsp), nested_nmi, first_nmi + lea 6*8(%rsp), %rdx + /* Compare the NMI stack (rdx) with the stack we came from (4*8(%rsp)) */ + cmpq %rdx, 4*8(%rsp) + /* If the stack pointer is above the NMI stack, this is a normal NMI */ + ja first_nmi + subq $EXCEPTION_STKSZ, %rdx + cmpq %rdx, 4*8(%rsp) + /* If it is below the NMI stack, it is a normal NMI */ + jb first_nmi + /* Ah, it is within the NMI stack, treat it as nested */ + jmp nested_nmi + CFI_REMEMBER_STATE nested_nmi: -- 1.8.1.4 -- 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/