From patchwork Tue Apr 14 06:23:13 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: KOSAKI Motohiro X-Patchwork-Id: 25922 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by ozlabs.org (Postfix) with ESMTP id A9DF1DDF7B for ; Tue, 14 Apr 2009 16:23:23 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753333AbZDNGXT (ORCPT ); Tue, 14 Apr 2009 02:23:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754027AbZDNGXS (ORCPT ); Tue, 14 Apr 2009 02:23:18 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:56159 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753626AbZDNGXQ (ORCPT ); Tue, 14 Apr 2009 02:23:16 -0400 Received: from m5.gw.fujitsu.co.jp ([10.0.50.75]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n3E6NF2h031549 (envelope-from kosaki.motohiro@jp.fujitsu.com); Tue, 14 Apr 2009 15:23:15 +0900 Received: from smail (m5 [127.0.0.1]) by outgoing.m5.gw.fujitsu.co.jp (Postfix) with ESMTP id 1A62745DE4D; Tue, 14 Apr 2009 15:23:15 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (s5.gw.fujitsu.co.jp [10.0.50.95]) by m5.gw.fujitsu.co.jp (Postfix) with ESMTP id E18F345DE4F; Tue, 14 Apr 2009 15:23:14 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id BF5BD1DB805F; Tue, 14 Apr 2009 15:23:14 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.249.87.104]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id 75CB81DB805B; Tue, 14 Apr 2009 15:23:14 +0900 (JST) Received: from ml14.css.fujitsu.com (ml14 [127.0.0.1]) by ml14.s.css.fujitsu.com (Postfix) with ESMTP id 4DF159F6020; Tue, 14 Apr 2009 15:23:14 +0900 (JST) Received: from [127.0.0.1] (unknown [10.124.100.179]) by ml14.s.css.fujitsu.com (Postfix) with ESMTP id 9FC719F5FFF; Tue, 14 Apr 2009 15:23:13 +0900 (JST) From: KOSAKI Motohiro To: LKML Subject: [RFC][PATCH v3 6/6] fix wrong get_user_pages usage in iovlock.c Cc: kosaki.motohiro@jp.fujitsu.com, Linus Torvalds , Andrew Morton , Nick Piggin , Andrea Arcangeli , Jeff Moyer , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Maciej Sosnowski , "David S. Miller" , Chris Leech , netdev@vger.kernel.org In-Reply-To: <20090414151204.C647.A69D9226@jp.fujitsu.com> References: <20090414151204.C647.A69D9226@jp.fujitsu.com> Message-Id: <20090414152151.C659.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 X-Mailer: Becky! ver. 2.50 [ja] Date: Tue, 14 Apr 2009 15:23:13 +0900 (JST) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org I don't have NET-DMA usable device. I hope to get expert review. --- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html ========================= Subject: [Untested][RFC][PATCH] fix wrong get_user_pages usage in iovlock.c down_read(mmap_sem) get_user_pages() up_read(mmap_sem) is fork unsafe. fix it. Signed-off-by: KOSAKI Motohiro Cc: Maciej Sosnowski Cc: David S. Miller Cc: Chris Leech Cc: netdev@vger.kernel.org --- drivers/dma/iovlock.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) Index: b/drivers/dma/iovlock.c =================================================================== --- a/drivers/dma/iovlock.c 2009-02-21 16:53:23.000000000 +0900 +++ b/drivers/dma/iovlock.c 2009-04-13 04:46:02.000000000 +0900 @@ -94,18 +94,10 @@ struct dma_pinned_list *dma_pin_iovec_pa pages += page_list->nr_pages; /* pin pages down */ - down_read(¤t->mm->mmap_sem); - ret = get_user_pages( - current, - current->mm, - (unsigned long) iov[i].iov_base, - page_list->nr_pages, - 1, /* write */ - 0, /* force */ - page_list->pages, - NULL); - up_read(¤t->mm->mmap_sem); - + down_read(¤t->mm->mm_pinned_sem); + ret = get_user_pages_fast((unsigned long) iov[i].iov_base, + page_list->nr_pages, 1, + page_list->pages); if (ret != page_list->nr_pages) goto unpin; @@ -127,6 +119,8 @@ void dma_unpin_iovec_pages(struct dma_pi if (!pinned_list) return; + up_read(¤t->mm->mm_pinned_sem); + for (i = 0; i < pinned_list->nr_iovecs; i++) { struct dma_page_list *page_list = &pinned_list->page_list[i]; for (j = 0; j < page_list->nr_pages; j++) {