From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751916AbdH3PAh (ORCPT ); Wed, 30 Aug 2017 11:00:37 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:36920 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751456AbdH3PAd (ORCPT ); Wed, 30 Aug 2017 11:00:33 -0400 From: Christoph Hellwig To: viro@zeniv.linux.org.uk Cc: arve@android.com, riandrews@android.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 07/16] serial2002: switch serial2002_tty_write to kernel_{read/write} Date: Wed, 30 Aug 2017 16:59:58 +0200 Message-Id: <20170830150007.3953-8-hch@lst.de> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170830150007.3953-1-hch@lst.de> References: <20170830150007.3953-1-hch@lst.de> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Instead of playing games with the address limit. This also gains us proper usage of the write counter, time stamp updates and kvec validation. Signed-off-by: Christoph Hellwig --- drivers/staging/comedi/drivers/serial2002.c | 24 +++++------------------- 1 file changed, 5 insertions(+), 19 deletions(-) diff --git a/drivers/staging/comedi/drivers/serial2002.c b/drivers/staging/comedi/drivers/serial2002.c index 0d33e520f635..cc18e25103ca 100644 --- a/drivers/staging/comedi/drivers/serial2002.c +++ b/drivers/staging/comedi/drivers/serial2002.c @@ -106,16 +106,8 @@ static long serial2002_tty_ioctl(struct file *f, unsigned int op, static int serial2002_tty_write(struct file *f, unsigned char *buf, int count) { - const char __user *p = (__force const char __user *)buf; - int result; - loff_t offset = 0; - mm_segment_t oldfs; - - oldfs = get_fs(); - set_fs(KERNEL_DS); - result = __vfs_write(f, p, count, &offset); - set_fs(oldfs); - return result; + loff_t pos = 0; + return kernel_write(f, buf, count, &pos); } static void serial2002_tty_read_poll_wait(struct file *f, int timeout) @@ -148,19 +140,14 @@ static int serial2002_tty_read(struct file *f, int timeout) { unsigned char ch; int result; + loff_t pos = 0; result = -1; if (!IS_ERR(f)) { - mm_segment_t oldfs; - char __user *p = (__force char __user *)&ch; - loff_t offset = 0; - - oldfs = get_fs(); - set_fs(KERNEL_DS); if (f->f_op->poll) { serial2002_tty_read_poll_wait(f, timeout); - if (__vfs_read(f, p, 1, &offset) == 1) + if (kernel_read(f, &ch, 1, &pos) == 1) result = ch; } else { /* Device does not support poll, busy wait */ @@ -171,14 +158,13 @@ static int serial2002_tty_read(struct file *f, int timeout) if (retries >= timeout) break; - if (__vfs_read(f, p, 1, &offset) == 1) { + if (kernel_read(f, &ch, 1, &pos) == 1) { result = ch; break; } usleep_range(100, 1000); } } - set_fs(oldfs); } return result; } -- 2.11.0