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=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, USER_AGENT_MUTT 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 6ABBAC282DA for ; Wed, 17 Apr 2019 21:31:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2DA602183E for ; Wed, 17 Apr 2019 21:31:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="njlU1ILK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733302AbfDQVbz (ORCPT ); Wed, 17 Apr 2019 17:31:55 -0400 Received: from mail-wr1-f54.google.com ([209.85.221.54]:44760 "EHLO mail-wr1-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725848AbfDQVbz (ORCPT ); Wed, 17 Apr 2019 17:31:55 -0400 Received: by mail-wr1-f54.google.com with SMTP id w18so184686wrv.11 for ; Wed, 17 Apr 2019 14:31:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :user-agent; bh=sYW8lwz4YkKdb66JKELKl8FrmGviUYgvoOuvSaDD9Kk=; b=njlU1ILKiYIQzfJ2I9kWI8kUgw1n/MNjml+x6V2Qmco0a26RASwolTf8iZ0Ea//gbc Wy+W4n/ZZT3c7lbKkh320nXyNoAH0zFlHcAjW0DZ9SW6CQbe6dupnhvvq91af0BNBnbd nREHyXoFJQJk5xCkEI6n01INGs2tygqEEp8XCLCn0e5X0BwcKMzRQdXrrC3KsWVBVVY8 vjXMDSshWTl1QDSjZVgYnh75twcsXvZwrF9LZZrLu9cNX/I6jLolhP3Pu/sbF+ko9phK Swg2hpqz5TSquUn0KB61ptpCHL+1ypRRBfVKzWMJnfi9KgqBuPsHn5fIjA3Govn7/xm4 B0Vw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:user-agent; bh=sYW8lwz4YkKdb66JKELKl8FrmGviUYgvoOuvSaDD9Kk=; b=uVmhzGed6LVe4ct5f8GDkccSm/laS4i5g5gG0/pSU4iRavErrGqgqQZ7VPbZKOkLm1 m8HKb+MxbydEPNb7aNgg+i0QFPz2er7FBbRvtMkvP7iKr+zk/zC3kCMTu1vFUGgMzpfL SOSCLA18AcD61JBz8YFsNpN5dmMRfZB+ZCtrtXZWZzvRq/f1k/ky39q+1gCbLdKR7s3i tTbWQxyQsGyauO5XdRxrTGxoxs+KvDQyYrgME5nhkmPucN/9MNoAU3QpHtLtDZhEGu/F AI02kCnHCtTXLNFLk3gWvJSk+K2NUYKcooMFaRMgITAOT/pnNjbOSd0Tf92XkoHbGNZk A46w== X-Gm-Message-State: APjAAAXNPGV7Yujbg7equ9NBwfP0qnJ6fgwGQmiANj5nV3rOTez4JWi+ IYdedxd2itSn3Y3argr13Tcbxyw= X-Google-Smtp-Source: APXvYqzVHnKwf21ESyAt9lwSkD1mlm1hm9xnfEnM4L+SnozNsh28dK4AhL3suOl3CHopDfS3SUUcyA== X-Received: by 2002:adf:fec3:: with SMTP id q3mr59393229wrs.173.1555536713268; Wed, 17 Apr 2019 14:31:53 -0700 (PDT) Received: from avx2 ([46.53.244.117]) by smtp.gmail.com with ESMTPSA id l20sm74276wme.20.2019.04.17.14.31.51 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 17 Apr 2019 14:31:52 -0700 (PDT) Date: Thu, 18 Apr 2019 00:31:50 +0300 From: Alexey Dobriyan To: akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH] exec: move ->recursion_depth out of critical sections Message-ID: <20190417213150.GA26474@avx2> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ->recursion_depth is changed only by current, therefore decrementing can be done without taking any locks. Signed-off-by: Alexey Dobriyan --- fs/exec.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/fs/exec.c +++ b/fs/exec.c @@ -1652,11 +1652,13 @@ int search_binary_handler(struct linux_binprm *bprm) if (!try_module_get(fmt->module)) continue; read_unlock(&binfmt_lock); + bprm->recursion_depth++; retval = fmt->load_binary(bprm); + bprm->recursion_depth--; + read_lock(&binfmt_lock); put_binfmt(fmt); - bprm->recursion_depth--; if (retval < 0 && !bprm->mm) { /* we got to flush_old_exec() and failed after it */ read_unlock(&binfmt_lock);