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=-19.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 8BE22C433DB for ; Sat, 13 Feb 2021 19:20:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DD8F64E44 for ; Sat, 13 Feb 2021 19:20:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229839AbhBMTUj (ORCPT ); Sat, 13 Feb 2021 14:20:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:49094 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229744AbhBMTU3 (ORCPT ); Sat, 13 Feb 2021 14:20:29 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 72DB864E51; Sat, 13 Feb 2021 19:19:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1613243988; bh=0NZfAn33OzbNo1CiIh5EPbmvmV4T8Va4cABUBaf/uOs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=P/TwtpemCRaT9vmbfawjfkPzjkLYu2PYmy+k1fm8CXRJJSCutcXzN/t0ltPTmfeUx o4C5R3D7mRtKZ6V1YPRRjpr43N99O8r1qzR11OWGzEFvdwNRiIGcbGpzVnTmKSeZIF dbKUfK8NM6Bh/Qkj0LbtMPQpKrHQq/D7wwFCT6PYbOoD6z75d+xP645WUcfLPo1NlF cA3nHNraJr9PPfUXfLrenCT2/jhxeMGea4UN+8TOF5xvKwA7m9knLh2jMBPox4lLMu n/ShpigswqTUBBxhnldLAgsrNAJUF5F1cCH9Hj9efYaQH6HRNWRzQ8bFtKEOtNa5mw GuISfgz4xV+Ew== From: Andy Lutomirski To: x86@kernel.org Cc: LKML , Sedat Dilek , Nick Desaulniers , Sean Christopherson , Brian Gerst , Joerg Roedel , Andy Lutomirski Subject: [PATCH v2 2/2] x86/entry/32: Remove leftover macros after stackprotector cleanups Date: Sat, 13 Feb 2021 11:19:45 -0800 Message-Id: X-Mailer: git-send-email 2.29.2 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now that nonlazy-GS mode is gone, remove the macros from entry_32.S that obfuscated^Wabstracted GS handling. The assembled output is identical before and after this patch. Cc: Sedat Dilek Cc: Nick Desaulniers Signed-off-by: Andy Lutomirski --- arch/x86/entry/entry_32.S | 43 ++------------------------------------- 1 file changed, 2 insertions(+), 41 deletions(-) diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index eb0cb662bca5..bee9101e211e 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -53,35 +53,6 @@ #define PTI_SWITCH_MASK (1 << PAGE_SHIFT) -/* - * User gs save/restore - * - * This is leftover junk from CONFIG_X86_32_LAZY_GS. A subsequent patch - * will remove it entirely. - */ - /* unfortunately push/pop can't be no-op */ -.macro PUSH_GS - pushl $0 -.endm -.macro POP_GS pop=0 - addl $(4 + \pop), %esp -.endm -.macro POP_GS_EX -.endm - - /* all the rest are no-op */ -.macro PTGS_TO_GS -.endm -.macro PTGS_TO_GS_EX -.endm -.macro GS_TO_REG reg -.endm -.macro REG_TO_PTGS reg -.endm -.macro SET_KERNEL_GS reg -.endm - - /* Unconditionally switch to user cr3 */ .macro SWITCH_TO_USER_CR3 scratch_reg:req ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_PTI @@ -234,7 +205,7 @@ .macro SAVE_ALL pt_regs_ax=%eax switch_stacks=0 skip_gs=0 unwind_espfix=0 cld .if \skip_gs == 0 - PUSH_GS + pushl $0 .endif pushl %fs @@ -259,9 +230,6 @@ movl $(__USER_DS), %edx movl %edx, %ds movl %edx, %es -.if \skip_gs == 0 - SET_KERNEL_GS %edx -.endif /* Switch to kernel stack if necessary */ .if \switch_stacks > 0 SWITCH_TO_KERNEL_STACK @@ -300,7 +268,7 @@ 1: popl %ds 2: popl %es 3: popl %fs - POP_GS \pop + addl $(4 + \pop), %esp /* pop the unused "gs" slot */ IRET_FRAME .pushsection .fixup, "ax" 4: movl $0, (%esp) @@ -313,7 +281,6 @@ _ASM_EXTABLE(1b, 4b) _ASM_EXTABLE(2b, 5b) _ASM_EXTABLE(3b, 6b) - POP_GS_EX .endm .macro RESTORE_ALL_NMI cr3_reg:req pop=0 @@ -928,7 +895,6 @@ SYM_FUNC_START(entry_SYSENTER_32) movl PT_EIP(%esp), %edx /* pt_regs->ip */ movl PT_OLDESP(%esp), %ecx /* pt_regs->sp */ 1: mov PT_FS(%esp), %fs - PTGS_TO_GS popl %ebx /* pt_regs->bx */ addl $2*4, %esp /* skip pt_regs->cx and pt_regs->dx */ @@ -964,7 +930,6 @@ SYM_FUNC_START(entry_SYSENTER_32) jmp 1b .popsection _ASM_EXTABLE(1b, 2b) - PTGS_TO_GS_EX .Lsysenter_fix_flags: pushl $X86_EFLAGS_FIXED @@ -1106,11 +1071,7 @@ SYM_CODE_START_LOCAL_NOALIGN(handle_exception) SAVE_ALL switch_stacks=1 skip_gs=1 unwind_espfix=1 ENCODE_FRAME_POINTER - /* fixup %gs */ - GS_TO_REG %ecx movl PT_GS(%esp), %edi # get the function address - REG_TO_PTGS %ecx - SET_KERNEL_GS %ecx /* fixup orig %eax */ movl PT_ORIG_EAX(%esp), %edx # get the error code -- 2.29.2