Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934244AbbHLJLz (ORCPT ); Wed, 12 Aug 2015 05:11:55 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:60942 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964848AbbHLI62 (ORCPT ); Wed, 12 Aug 2015 04:58:28 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Denys Vlasenko , Alexei Starovoitov , Andy Lutomirski , Borislav Petkov , Frederic Weisbecker , "H. Peter Anvin" , Kees Cook , Linus Torvalds , Oleg Nesterov , Steven Rostedt , Will Drewry , Ingo Molnar , Ben Hutchings , Luis Henriques Subject: [PATCH 3.16.y-ckt 048/118] x86/asm/entry/64: Fold the 'test_in_nmi' macro into its only user Date: Wed, 12 Aug 2015 09:55:50 +0100 Message-Id: <1439369820-27005-49-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1439369820-27005-1-git-send-email-luis.henriques@canonical.com> References: <1439369820-27005-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2612 Lines: 81 3.16.7-ckt16 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Denys Vlasenko commit 0784b36448a2a85b95b6eb21a69b9045c896c065 upstream. No code changes. Signed-off-by: Denys Vlasenko Acked-by: Borislav Petkov Cc: Alexei Starovoitov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Steven Rostedt Cc: Will Drewry Link: http://lkml.kernel.org/r/1427899858-7165-1-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar Signed-off-by: Ben Hutchings Signed-off-by: Luis Henriques --- arch/x86/kernel/entry_64.S | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 94aa18a9cc11..c13aaaac878b 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -1423,19 +1423,7 @@ 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 @@ -1496,8 +1484,18 @@ 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: -- 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/