From patchwork Sun Feb 23 08:53:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Macpaul Lin X-Patchwork-Id: 11398725 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 D7192138D for ; Sun, 23 Feb 2020 08:53:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B638C208C3 for ; Sun, 23 Feb 2020 08:53:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b="WnM6R2F7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727033AbgBWIx2 (ORCPT ); Sun, 23 Feb 2020 03:53:28 -0500 Received: from mailgw02.mediatek.com ([210.61.82.184]:22825 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726592AbgBWIx2 (ORCPT ); Sun, 23 Feb 2020 03:53:28 -0500 X-UUID: 38e39728baba4c5a88c3e39a367ab3e1-20200223 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=L6+Le50jyFOltKwz1JENBOZc2qg1uyeNTqnh9DLfcl4=; b=WnM6R2F75bga3qqX7bdF+i6UDekkzY4y8slHZtEFTxxHqj0R3TmWLYniNfaMKj9YLekaSJCowU+6KZ8ZD8PJ8yyndwNiq0OIXeDBNL6BXyL2Gx9flOZYilIVHas3Wn0zK6zVs0OBjQH49DaWz9jVmcXYkUaqAP0pVN2qpbbWHtY=; X-UUID: 38e39728baba4c5a88c3e39a367ab3e1-20200223 Received: from mtkcas09.mediatek.inc [(172.21.101.178)] by mailgw02.mediatek.com (envelope-from ) (Cellopoint E-mail Firewall v4.1.10 Build 0809 with TLS) with ESMTP id 574559612; Sun, 23 Feb 2020 16:53:24 +0800 Received: from mtkcas07.mediatek.inc (172.21.101.84) by mtkmbs01n1.mediatek.inc (172.21.101.68) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Sun, 23 Feb 2020 16:52:09 +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; Sun, 23 Feb 2020 16:52:29 +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 Subject: [PATCH] usb: gadget: f_fs: try to fix AIO issue under ARM 64 bit TAGGED mode Date: Sun, 23 Feb 2020 16:53:12 +0800 Message-ID: <1582447993-7594-1-git-send-email-macpaul.lin@mediatek.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: MIME-Version: 1.0 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 fisrt 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 gdaget'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 userspace 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 --- drivers/usb/gadget/function/f_fs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index ce1d023..b21541a 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -35,6 +35,7 @@ #include #include #include +#include #include "u_fs.h" #include "u_f.h" @@ -826,6 +827,8 @@ static void ffs_user_copy_worker(struct work_struct *work) if (io_data->read && ret > 0) { mm_segment_t oldfs = get_fs(); + if (IS_ENABLED(CONFIG_ARM64_TAGGED_ADDR_ABI)) + set_thread_flag(TIF_TAGGED_ADDR); set_fs(USER_DS); use_mm(io_data->mm); ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data);