From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8C8EECDFAA for ; Wed, 18 Jul 2018 09:44:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D87E2075C for ; Wed, 18 Jul 2018 09:44:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=8bytes.org header.i=@8bytes.org header.b="G91khPKc" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5D87E2075C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731991AbeGRKUo (ORCPT ); Wed, 18 Jul 2018 06:20:44 -0400 Received: from 8bytes.org ([81.169.241.247]:54196 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731581AbeGRKSf (ORCPT ); Wed, 18 Jul 2018 06:18:35 -0400 Received: by theia.8bytes.org (Postfix, from userid 1000) id 868AA561; Wed, 18 Jul 2018 11:41:20 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=8bytes.org; s=mail-1; t=1531906881; bh=vCQiJBAHo9odqKL67p3tHtdnNwklCpEkJ6suW4Lg8AA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=G91khPKcwY8cPO4eb2bwCs0BW484UQFn3DEAKLsbwXfhuk1q2vbbry+exMa9aiyTM +76f2ebu0x2o+i1Q8AQ2knFKyUTK/VrmSkq21ocMjSVzpqRT/IyHUYxqV94QpEpq7R xKD7DZ4nwCX3hGbEqg7K9dm9TFlyUKsy6U7gH195ePVHEFdYKhK6bS8w1CACjr4Ch3 CVEIAeY0vWDElRl+QyCpt1kD22LbBkSopif5HjFTpujp2zPMPQeO3xtgGN/8e5jjSR F1fKn+5B78ZUvgPM4pgszxn2hqaAgwBKOi7W8P0WMIHBdI9TgMnCr5FD2CkRDmuj1L PDywMxIf7u8cA== From: Joerg Roedel To: Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" Cc: x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Linus Torvalds , Andy Lutomirski , Dave Hansen , Josh Poimboeuf , Juergen Gross , Peter Zijlstra , Borislav Petkov , Jiri Kosina , Boris Ostrovsky , Brian Gerst , David Laight , Denys Vlasenko , Eduardo Valentin , Greg KH , Will Deacon , aliguori@amazon.com, daniel.gruss@iaik.tugraz.at, hughd@google.com, keescook@google.com, Andrea Arcangeli , Waiman Long , Pavel Machek , "David H . Gutteridge" , jroedel@suse.de, joro@8bytes.org Subject: [PATCH 11/39] x86/entry/32: Simplify debug entry point Date: Wed, 18 Jul 2018 11:40:48 +0200 Message-Id: <1531906876-13451-12-git-send-email-joro@8bytes.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1531906876-13451-1-git-send-email-joro@8bytes.org> References: <1531906876-13451-1-git-send-email-joro@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joerg Roedel The common exception entry code now handles the entry-from-sysenter stack situation and makes sure to leave with the same stack as it entered the kernel. So there is no need anymore for the special handling in the debug entry code. Signed-off-by: Joerg Roedel --- arch/x86/entry/entry_32.S | 35 +++-------------------------------- 1 file changed, 3 insertions(+), 32 deletions(-) diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 9d6eceb..dbf7d61 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -1226,41 +1226,12 @@ END(common_exception) ENTRY(debug) /* - * #DB can happen at the first instruction of - * entry_SYSENTER_32 or in Xen's SYSENTER prologue. If this - * happens, then we will be running on a very small stack. We - * need to detect this condition and switch to the thread - * stack before calling any C code at all. - * - * If you edit this code, keep in mind that NMIs can happen in here. + * Entry from sysenter is now handled in common_exception */ ASM_CLAC pushl $-1 # mark this as an int - - SAVE_ALL - ENCODE_FRAME_POINTER - xorl %edx, %edx # error code 0 - movl %esp, %eax # pt_regs pointer - - /* Are we currently on the SYSENTER stack? */ - movl PER_CPU_VAR(cpu_entry_area), %ecx - addl $CPU_ENTRY_AREA_entry_stack + SIZEOF_entry_stack, %ecx - subl %eax, %ecx /* ecx = (end of entry_stack) - esp */ - cmpl $SIZEOF_entry_stack, %ecx - jb .Ldebug_from_sysenter_stack - - TRACE_IRQS_OFF - call do_debug - jmp ret_from_exception - -.Ldebug_from_sysenter_stack: - /* We're on the SYSENTER stack. Switch off. */ - movl %esp, %ebx - movl PER_CPU_VAR(cpu_current_top_of_stack), %esp - TRACE_IRQS_OFF - call do_debug - movl %ebx, %esp - jmp ret_from_exception + pushl $do_debug + jmp common_exception END(debug) /* -- 2.7.4