From patchwork Mon Mar 13 22:14:10 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Till Smejkal X-Patchwork-Id: 738521 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3vhydp2ygdz9s7g for ; Tue, 14 Mar 2017 13:01:34 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="KG2TPcg8"; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=googlemail.com header.i=@googlemail.com header.b="vMhH71+E"; dkim-atps=neutral DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=FHNEuhNs62J+9WacBD2iAFLM77IaOlRiHsfIGjneuP4=; b=KG2TPcg82IORoT7YgKrFJWSJkw ayQ9FOVAGBajbBE42qtpzlbwvsWpGUwsQvZa5weLhRoPlMmU36e7YyZakMdDik5f0cCPUXPVB/e8K wD4UGquzHhLBVQql6O1ZMmTwaWcIYVsA6FRKS0wBZ3tHnrPka/eq2apHHyhcl0hcq9lsCIAZvAUHF ycttdZS7D4L9sNv2RtbvG0UJ97BbIYvlmvXj99/nd5JVf92hRX+2Rvoq05uRql0gypI48IV40XlsI goSk6uJIIZy7sVO2JrLkblGUgic083p5bUKWfMvTUqQztveZ4VTER9w4kDiHNApV/nxn9Ps0yJKN1 KMC3Fujw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1cnbmH-0006Ah-0V; Tue, 14 Mar 2017 02:01:33 +0000 Received: from mail-wr0-x242.google.com ([2a00:1450:400c:c0c::242]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1cnYFB-0001mx-E9; Mon, 13 Mar 2017 22:15:12 +0000 Received: by mail-wr0-x242.google.com with SMTP id g10so21791813wrg.0; Mon, 13 Mar 2017 15:14:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=hPnPMUmdxCmL2VZfHCk49qFtrqUABprIraT2deulDPM=; b=vMhH71+EwFar6S8dJ+TBpuvjUbQQwW6fbFDyV+pzcRgqvD1Ws5qyzgc/gkt1bXxCFR xwQs/OJcq0wdTe1rd8t3EdrpLO1qe9gpAbhxRCQkua4e7JEeAEI0x5VzrNb23N5hsvG/ 1BonYZJIwyzfdW18iUSjX18fp4ywHZ/PM80CfRWlscq9+I5cfFs9qGktzcxGT9fKT+PG Eh9JZMMAJ5CYRQcP31FCvSzCgyN57+Bm2xTURxGnUPlvxv4r+uVfOPF+J1WTc9IFgbrW zO6/baRwKCwmlJxRZOr2ArDNDm7xJdy4QUQ4+M0lURgYnBV7P6pJyuiIJXGbGnn8cJjW mr6g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=hPnPMUmdxCmL2VZfHCk49qFtrqUABprIraT2deulDPM=; b=blm+eu1ZlUfvhDxPAnJvqYxj10Fqxpa9ZCnH8mIFGWLSIwI+Nz60q6/7eotj1uUGKE BzRFYH+fegaRrKfmJe/nberJzhfWK8yUOXi8kUEQW/kZFOnpGiqX/VEacu734BzCZRfG YPz2wiHRVVyLaBxblp/HJfWwBw4HHwMyqk1Ws00mxbos7fP7hXvxc5fxs8Zv3cBJgGwi MDSppu9pa927WHju6ncWE1uVEATvDOGRqluyAw9KoXt7FH8XIa6Anegb9vFvTw8UPCm1 V70mAi9zN2BaNPeCQY1fLIBc78nIL3Zh44w0/ZkYNeoIswJLBpagSh5FMi7vxPNvEJPU vUKw== X-Gm-Message-State: AMke39kMKvc1WQksD67QHUgMqbShuP5dYFeTWTBu1vZWtRppX7X4/xUjJYvBeUR3hMyQKQ== X-Received: by 10.223.163.195 with SMTP id m3mr29043535wrb.83.1489443291833; Mon, 13 Mar 2017 15:14:51 -0700 (PDT) Received: from localhost (login1.zih.tu-dresden.de. [141.76.16.140]) by smtp.googlemail.com with ESMTPSA id q4sm13025125wme.17.2017.03.13.15.14.50 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 13 Mar 2017 15:14:51 -0700 (PDT) From: Till Smejkal X-Google-Original-From: Till Smejkal To: Richard Henderson , Ivan Kokshaysky , Matt Turner , Vineet Gupta , Russell King , Catalin Marinas , Will Deacon , Steven Miao , Richard Kuo , Tony Luck , Fenghua Yu , James Hogan , Ralf Baechle , "James E.J. Bottomley" , Helge Deller , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Martin Schwidefsky , Heiko Carstens , Yoshinori Sato , Rich Felker , "David S. Miller" , Chris Metcalf , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Andy Lutomirski , Chris Zankel , Max Filippov , Arnd Bergmann , Greg Kroah-Hartman , Laurent Pinchart , Mauro Carvalho Chehab , Pawel Osciak , Marek Szyprowski , Kyungmin Park , David Woodhouse , Brian Norris , Boris Brezillon , Marek Vasut , Richard Weinberger , Cyrille Pitchen , Felipe Balbi , Alexander Viro , Benjamin LaHaise , Nadia Yvette Chambers , Jeff Layton , "J. Bruce Fields" , Peter Zijlstra , Hugh Dickins , Arnaldo Carvalho de Melo , Alexander Shishkin , Jaroslav Kysela , Takashi Iwai Subject: [RFC PATCH 08/13] kernel/fork: Define explicitly which mm_struct to duplicate during fork Date: Mon, 13 Mar 2017 15:14:10 -0700 Message-Id: <20170313221415.9375-9-till.smejkal@gmail.com> X-Mailer: git-send-email 2.12.0 In-Reply-To: <20170313221415.9375-1-till.smejkal@gmail.com> References: <20170313221415.9375-1-till.smejkal@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170313_151509_850183_E18E6EBD X-CRM114-Status: GOOD ( 12.30 ) X-Spam-Score: -2.0 (--) X-Spam-Report: SpamAssassin version 3.4.1 on bombadil.infradead.org summary: Content analysis details: (-2.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [2a00:1450:400c:c0c:0:0:0:242 listed in] [list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (till.smejkal[at]googlemail.com) -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid X-Mailman-Approved-At: Mon, 13 Mar 2017 19:01:29 -0700 X-BeenThere: linux-snps-arc@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Linux on Synopsys ARC Processors List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-mips@linux-mips.org, alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, linux-aio@kvack.org, linux-mm@kvack.org, linux-mtd@lists.infradead.org, sparclinux@vger.kernel.org, linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-sh@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-media@vger.kernel.org, linux-xtensa@linux-xtensa.org, adi-buildroot-devel@lists.sourceforge.net, linux-metag@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, linux-api@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, linux-fsdevel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org MIME-Version: 1.0 Sender: "linux-snps-arc" Errors-To: linux-snps-arc-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org The dup_mm-function used during 'do_fork' to duplicate the current task's mm_struct for the newly forked task always implicitly uses current->mm for this purpose. However, during copy_mm it was already decided which mm_struct to copy/duplicate. So pass this mm_struct to dup_mm instead of again deciding which mm_struct to use. Signed-off-by: Till Smejkal --- kernel/fork.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/fork.c b/kernel/fork.c index 9209f6d5d7c0..d3087d870855 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1158,9 +1158,10 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm) * Allocate a new mm structure and copy contents from the * mm structure of the passed in task structure. */ -static struct mm_struct *dup_mm(struct task_struct *tsk) +static struct mm_struct *dup_mm(struct task_struct *tsk, + struct mm_struct *oldmm) { - struct mm_struct *mm, *oldmm = current->mm; + struct mm_struct *mm; int err; mm = allocate_mm(); @@ -1226,7 +1227,7 @@ static int copy_mm(unsigned long clone_flags, struct task_struct *tsk) } retval = -ENOMEM; - mm = dup_mm(tsk); + mm = dup_mm(tsk, oldmm); if (!mm) goto fail_nomem;