From patchwork Wed Feb 26 12:01:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Macpaul Lin X-Patchwork-Id: 11406359 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3284992A for ; Wed, 26 Feb 2020 12:02:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 078B724688 for ; Wed, 26 Feb 2020 12:02:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b="ENbT1nfH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726926AbgBZMCP (ORCPT ); Wed, 26 Feb 2020 07:02:15 -0500 Received: from mailgw01.mediatek.com ([210.61.82.183]:6851 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726272AbgBZMCP (ORCPT ); Wed, 26 Feb 2020 07:02:15 -0500 X-UUID: 618771a74bec4bba8d11e5bc7ea6f553-20200226 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Transfer-Encoding:Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From; bh=HeqaTDjIL0PTx6tfNZRsJGOB5wSUUqHsQNV/Ncz2fJc=; b=ENbT1nfHLPmaa1KnVt+jRf/tknKxc2p2KiK+s6CU1rwJAp+Lk3CSRMzwDpCHeadWl1fqHuy8hhUWvULtNVcLJGPLWkNfldClAau63AQr7JW2Wod7LrFdac8b6i7YmPCYva695mdKqQLe76+fThWjqwBTnhRst8AF2MHGbGBUrjI=; X-UUID: 618771a74bec4bba8d11e5bc7ea6f553-20200226 Received: from mtkcas07.mediatek.inc [(172.21.101.84)] by mailgw01.mediatek.com (envelope-from ) (Cellopoint E-mail Firewall v4.1.10 Build 0809 with TLS) with ESMTP id 804146539; Wed, 26 Feb 2020 20:02:07 +0800 Received: from mtkcas07.mediatek.inc (172.21.101.84) by mtkmbs01n2.mediatek.inc (172.21.101.79) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Wed, 26 Feb 2020 19:57:57 +0800 Received: from mtkswgap22.mediatek.inc (172.21.77.33) by mtkcas07.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Wed, 26 Feb 2020 20:01:57 +0800 From: Macpaul Lin To: Matthias Brugger , Shen Jing , Sasha Levin , John Stultz , Andrzej Pietrasiewicz , Vincent Pelletier , Jerry Zhang , , , , , Mediatek WSD Upstream , CC Hwang , Loda Chou , Al Viro , , CC: Macpaul Lin , Peter Chen , Catalin Marinas , Miles Chen Subject: [PATCH v4] usb: gadget: f_fs: try to fix AIO issue under ARM 64 bit TAGGED mode Date: Wed, 26 Feb 2020 20:01:52 +0800 Message-ID: <1582718512-28923-1-git-send-email-macpaul.lin@mediatek.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1582627315-21123-1-git-send-email-macpaul.lin@mediatek.com> References: <1582627315-21123-1-git-send-email-macpaul.lin@mediatek.com> MIME-Version: 1.0 X-TM-SNTS-SMTP: 272F8CE54AD6E67D73DACACA69671537612B9D56AD5648D8354972DCC44EFC2F2000:8 X-MTK: N Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org This issue was found when adbd trying to open functionfs with AIO mode. Usually, we need to set "setprop sys.usb.ffs.aio_compat 0" to enable adbd with AIO mode on Android. When adbd is opening functionfs, it will try to read 24 bytes at the first read I/O control. If this reading has been failed, adbd will try to send FUNCTIONFS_CLEAR_HALT to functionfs. When adbd is in AIO mode, functionfs will be acted with asyncronized I/O path. After the successful read transfer has been completed by gadget hardware, the following series of functions will be called. ffs_epfile_async_io_complete() -> ffs_user_copy_worker() -> copy_to_iter() -> _copy_to_iter() -> copyout() -> iterate_and_advance() -> iterate_iovec() Adding debug trace to these functions, it has been found that in copyout(), access_ok() will check if the user space address is valid to write. However if CONFIG_ARM64_TAGGED_ADDR_ABI is enabled, adbd always passes user space address start with "0x3C" to gadget's AIO blocks. This tagged address will cause access_ok() check always fail. Which causes later calculation in iterate_iovec() turn zero. Copyout() won't copy data to user space since the length to be copied "v.iov_len" will be zero. Finally leads ffs_copy_to_iter() always return -EFAULT, causes adbd cannot open functionfs and send FUNCTIONFS_CLEAR_HALT. Signed-off-by: Macpaul Lin Cc: Peter Chen Cc: Catalin Marinas Cc: Miles Chen --- Changes for v4: - Abandon solution v3 by adding "TIF_TAGGED_ADDR" flag to gadget driver. According to Catalin's suggestion, change the solution by untagging user space address passed by AIO in gadget driver. Changes for v3: - Fix misspelling in commit message. Thanks for Peter's review. Changes for v2: - Fix build error for 32-bit load. An #if defined(CONFIG_ARM64) still need for avoiding undeclared defines. drivers/usb/gadget/function/f_fs.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index ce1d023..192935f 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -715,7 +715,20 @@ static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req) static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter) { - ssize_t ret = copy_to_iter(data, data_len, iter); + ssize_t ret; + +#if defined(CONFIG_ARM64) + /* + * Replace tagged address passed by user space application before + * copying. + */ + if (IS_ENABLED(CONFIG_ARM64_TAGGED_ADDR_ABI) && + (iter->type == ITER_IOVEC)) { + *(unsigned long *)&iter->iov->iov_base = + (unsigned long)untagged_addr(iter->iov->iov_base); + } +#endif + ret = copy_to_iter(data, data_len, iter); if (likely(ret == data_len)) return ret;