From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3339499-1523479928-2-4264838331673906497 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, MAILING_LIST_MULTI -1, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1523479927; b=Ni2HpuHtsORG09q9VNPkAm3q156xAguBK500ARgy7ysFPdkKUH RONvxHGzfrc/uSuNeWucoEeq4aJ6wy5IPrdES7GgJffa2k8rvlfv5VtazYBcpFl5 kDcHlnBp6ydlTlWtYpYWlGncpH3kso/iPy5hrKPNDCDvqBAvSz4mA24brplgAsco 9+0kqXSUHWv+jXkwG4B/TIB7K5c5oHWO5GHtyhm6YsyfdwgRNXMKtGiDPGU4mNn0 KwRjrDqLESxzmkty36ZqRqQtot4t4MWnGmsI7/WG+EUn36bpfdfN932A0M90Uttq gYNNia8PhNnAysz9aGJUC4GEST4rAVXeh9hA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=fm2; t=1523479927; bh=lUCrNVHr6ZVG139dEfVeuzniAZMhiF DX5ZU5MXEVIvM=; b=fwkTvO2MW3S3knuSnU2GSWhTpQ/SyJIGFulat+SD1HITNv gTgCN6glRm2vQwuX+ETz4qbek1UgNBUWpfZ1lLy55xhynvnwxJlssuyw712synKt c2FaAbXCyqE16TNLaZWzTLTlqHdM1QbLmZUoflRO4uGDX0NqifIEbwHiP7gG7kp8 FRqSEFwojfZyszDFNuNX0PTfitHc3aviZVmilSQnQMEpNM23Fnj//nWcvSHGs4Hh M4V6QcgcfWnfw+wVVQs+jEONdmm9uEFUU1rtPJf/zoq1374tgwRCOwqeq3eZNM/d fSzBAaXXg5wrGAfGVNsxpcf20uqzWztWRecA/D4A== ARC-Authentication-Results: i=1; mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfN1iuiw+zOLsCJJKnYSiMML4e5EyF4Ov997R+EKGFTjvJLFGGYhgfFcflrhsDzR7TccEWzUSjWQbhJKwBuO1SmuyfPws6UjugQCLwnNIjvFdfJaYbOhM Pm4tYOFCR2/ss2I705JoKKqBL6/ttKpRmg2lVgKbXUah2jPeJhUqlHxfVguH0OVoN2orF/ue74IA3WxyfRX5/xzzjXSMNqyVnd5LlWlZ23ONWrNMJatMSt1A X-CM-Analysis: v=2.3 cv=Tq3Iegfh c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=IkcTkHD0fZMA:10 a=Kd1tUaAdevIA:10 a=ag1SF4gXAAAA:8 a=yMhMjlubAAAA:8 a=pXsxn4-ixa34lSzHDawA:9 a=QEXdDO2ut3YA:10 a=Yupwre4RP9_Eg_Bd0iYG:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755537AbeDKSpd (ORCPT ); Wed, 11 Apr 2018 14:45:33 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:58608 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755500AbeDKSpb (ORCPT ); Wed, 11 Apr 2018 14:45:31 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Geert Uytterhoeven , Sasha Levin Subject: [PATCH 4.4 048/190] serial: sh-sci: Fix race condition causing garbage during shutdown Date: Wed, 11 Apr 2018 20:34:54 +0200 Message-Id: <20180411183553.074508354@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180411183550.114495991@linuxfoundation.org> References: <20180411183550.114495991@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Geert Uytterhoeven [ Upstream commit 1cf4a7efdc71cab84c42cfea7200608711ea954f ] If DMA is enabled and used, a burst of old data may be seen on the serial console during "poweroff" or "reboot". uart_flush_buffer() clears the circular buffer, but sci_port.tx_dma_len is not reset. This leads to a circular buffer overflow, dumping (UART_XMIT_SIZE - sci_port.tx_dma_len) bytes. To fix this, add a .flush_buffer() callback that resets sci_port.tx_dma_len. Inspired by commit 31ca2c63fdc0aee7 ("tty/serial: atmel: fix race condition (TX+DMA)"). Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sh-sci.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1457,7 +1457,16 @@ static void sci_free_dma(struct uart_por if (s->chan_rx) sci_rx_dma_release(s, false); } -#else + +static void sci_flush_buffer(struct uart_port *port) +{ + /* + * In uart_flush_buffer(), the xmit circular buffer has just been + * cleared, so we have to reset tx_dma_len accordingly. + */ + to_sci_port(port)->tx_dma_len = 0; +} +#else /* !CONFIG_SERIAL_SH_SCI_DMA */ static inline void sci_request_dma(struct uart_port *port) { } @@ -1465,7 +1474,9 @@ static inline void sci_request_dma(struc static inline void sci_free_dma(struct uart_port *port) { } -#endif + +#define sci_flush_buffer NULL +#endif /* !CONFIG_SERIAL_SH_SCI_DMA */ static irqreturn_t sci_rx_interrupt(int irq, void *ptr) { @@ -2205,6 +2216,7 @@ static struct uart_ops sci_uart_ops = { .break_ctl = sci_break_ctl, .startup = sci_startup, .shutdown = sci_shutdown, + .flush_buffer = sci_flush_buffer, .set_termios = sci_set_termios, .pm = sci_pm, .type = sci_type,