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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 08DCDC4CEC4 for ; Thu, 19 Sep 2019 02:09:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CEA45214AF for ; Thu, 19 Sep 2019 02:09:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730685AbfISCJQ (ORCPT ); Wed, 18 Sep 2019 22:09:16 -0400 Received: from mga03.intel.com ([134.134.136.65]:43868 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726812AbfISCJP (ORCPT ); Wed, 18 Sep 2019 22:09:15 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Sep 2019 19:09:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,522,1559545200"; d="scan'208";a="212066086" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by fmsmga004.fm.intel.com with ESMTP; 18 Sep 2019 19:09:13 -0700 From: Wei Yang To: dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Wei Yang Subject: [PATCH 1/2] x86/mm: consolidate bad_area handling to the end Date: Thu, 19 Sep 2019 10:08:43 +0800 Message-Id: <20190919020844.27461-1-richardw.yang@linux.intel.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are totally 7 bad_area[_nosemaphore] error branch in do_user_addr_fault(). Consolidate all these handling to the end to make the code a little neat. BTW, after doing so, function bad_area is not used any more. Remove it. Signed-off-by: Wei Yang --- arch/x86/mm/fault.c | 44 ++++++++++++++++---------------------------- 1 file changed, 16 insertions(+), 28 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 9ceacd1156db..9d18b73b5f77 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -933,12 +933,6 @@ __bad_area(struct pt_regs *regs, unsigned long error_code, __bad_area_nosemaphore(regs, error_code, address, pkey, si_code); } -static noinline void -bad_area(struct pt_regs *regs, unsigned long error_code, unsigned long address) -{ - __bad_area(regs, error_code, address, 0, SEGV_MAPERR); -} - static inline bool bad_area_access_from_pkeys(unsigned long error_code, struct vm_area_struct *vma) { @@ -1313,19 +1307,14 @@ void do_user_addr_fault(struct pt_regs *regs, if (unlikely(cpu_feature_enabled(X86_FEATURE_SMAP) && !(hw_error_code & X86_PF_USER) && !(regs->flags & X86_EFLAGS_AC))) - { - bad_area_nosemaphore(regs, hw_error_code, address); - return; - } + goto bad_area_nosem; /* * If we're in an interrupt, have no user context or are running * in a region with pagefaults disabled then we must not take the fault */ - if (unlikely(faulthandler_disabled() || !mm)) { - bad_area_nosemaphore(regs, hw_error_code, address); - return; - } + if (unlikely(faulthandler_disabled() || !mm)) + goto bad_area_nosem; /* * It's safe to allow irq's after cr2 has been saved and the @@ -1385,8 +1374,7 @@ void do_user_addr_fault(struct pt_regs *regs, * Fault from code in kernel from * which we do not expect faults. */ - bad_area_nosemaphore(regs, hw_error_code, address); - return; + goto bad_area_nosem; } retry: down_read(&mm->mmap_sem); @@ -1400,20 +1388,14 @@ void do_user_addr_fault(struct pt_regs *regs, } vma = find_vma(mm, address); - if (unlikely(!vma)) { - bad_area(regs, hw_error_code, address); - return; - } + if (unlikely(!vma)) + goto bad_area; if (likely(vma->vm_start <= address)) goto good_area; - if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) { - bad_area(regs, hw_error_code, address); - return; - } - if (unlikely(expand_stack(vma, address))) { - bad_area(regs, hw_error_code, address); - return; - } + if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) + goto bad_area; + if (unlikely(expand_stack(vma, address))) + goto bad_area; /* * Ok, we have a good vm_area for this memory access, so @@ -1483,6 +1465,12 @@ void do_user_addr_fault(struct pt_regs *regs, } check_v8086_mode(regs, address, tsk); + return; + +bad_area: + up_read(&mm->mmap_sem); +bad_area_nosem: + bad_area_nosemaphore(regs, hw_error_code, address); } NOKPROBE_SYMBOL(do_user_addr_fault); -- 2.17.1