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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNPARSEABLE_RELAY,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 ACB5FC4321D for ; Wed, 15 Aug 2018 18:50:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 478E221528 for ; Wed, 15 Aug 2018 18:50:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 478E221528 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com 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 S1727649AbeHOVnr (ORCPT ); Wed, 15 Aug 2018 17:43:47 -0400 Received: from out30-133.freemail.mail.aliyun.com ([115.124.30.133]:60899 "EHLO out30-133.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727592AbeHOVnq (ORCPT ); Wed, 15 Aug 2018 17:43:46 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R181e4;CH=green;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01422;MF=yang.shi@linux.alibaba.com;NM=1;PH=DS;RN=15;SR=0;TI=SMTPD_---0T6gJtNa_1534358999; Received: from e19h19392.et15sqa.tbsite.net(mailfrom:yang.shi@linux.alibaba.com fp:SMTPD_---0T6gJtNa_1534358999) by smtp.aliyun-inc.com(127.0.0.1); Thu, 16 Aug 2018 02:50:07 +0800 From: Yang Shi To: mhocko@kernel.org, willy@infradead.org, ldufour@linux.vnet.ibm.com, kirill@shutemov.name, vbabka@suse.cz, akpm@linux-foundation.org, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, alexander.shishkin@linux.intel.com, jolsa@redhat.com, namhyung@kernel.org Cc: yang.shi@linux.alibaba.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [RFC v8 PATCH 2/5] uprobes: introduce has_uprobes helper Date: Thu, 16 Aug 2018 02:49:47 +0800 Message-Id: <1534358990-85530-3-git-send-email-yang.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1534358990-85530-1-git-send-email-yang.shi@linux.alibaba.com> References: <1534358990-85530-1-git-send-email-yang.shi@linux.alibaba.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We need check if mm or vma has uprobes in the following patch to check if a vma could be unmapped with holding read mmap_sem. The checks and pre-conditions used by uprobe_munmap() look just suitable for this purpose. Extracting those checks into a helper function, has_uprobes(). Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Vlastimil Babka Signed-off-by: Yang Shi --- include/linux/uprobes.h | 7 +++++++ kernel/events/uprobes.c | 23 ++++++++++++++++------- 2 files changed, 23 insertions(+), 7 deletions(-) diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index 0a294e9..418764e 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -149,6 +149,8 @@ struct uprobes_state { extern bool arch_uprobe_ignore(struct arch_uprobe *aup, struct pt_regs *regs); extern void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr, void *src, unsigned long len); +extern bool has_uprobes(struct vm_area_struct *vma, unsigned long start, + unsigned long end); #else /* !CONFIG_UPROBES */ struct uprobes_state { }; @@ -203,5 +205,10 @@ static inline void uprobe_copy_process(struct task_struct *t, unsigned long flag static inline void uprobe_clear_state(struct mm_struct *mm) { } +static inline bool has_uprobes(struct vm_area_struct *vma, unsigned long start, + unsgined long end) +{ + return false; +} #endif /* !CONFIG_UPROBES */ #endif /* _LINUX_UPROBES_H */ diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index aed1ba5..568481c 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1114,22 +1114,31 @@ int uprobe_mmap(struct vm_area_struct *vma) return !!n; } -/* - * Called in context of a munmap of a vma. - */ -void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end) +bool +has_uprobes(struct vm_area_struct *vma, unsigned long start, unsigned long end) { if (no_uprobe_events() || !valid_vma(vma, false)) - return; + return false; if (!atomic_read(&vma->vm_mm->mm_users)) /* called by mmput() ? */ - return; + return false; if (!test_bit(MMF_HAS_UPROBES, &vma->vm_mm->flags) || test_bit(MMF_RECALC_UPROBES, &vma->vm_mm->flags)) - return; + return false; if (vma_has_uprobes(vma, start, end)) + return true; + + return false; +} + +/* + * Called in context of a munmap of a vma. + */ +void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end) +{ + if (has_uprobes(vma, start, end)) set_bit(MMF_RECALC_UPROBES, &vma->vm_mm->flags); } -- 1.8.3.1