From mboxrd@z Thu Jan 1 00:00:00 1970 From: nikai@nikai.net (Nicolas Kaiser) Date: Fri, 22 Oct 2010 20:30:39 +0200 Subject: [PATCH] dma/coh901318: use simple_read_from_buffer In-Reply-To: <201010221938.12591.arnd@arndb.de> References: <20101022192953.1f67b10a@absol.kitzblitz> <201010221938.12591.arnd@arndb.de> Message-ID: <20101022203039.7b353056@absol.kitzblitz> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org * Arnd Bergmann : > On Friday 22 October 2010 19:29:53 Nicolas Kaiser wrote: > > If copy_to_user fails, the assigned error code instantly gets > > overwritten, and the failure apparently ignored. Moreover, > > shouldn't the error code be -EFAULT instead of -EINVAL? > > Looks good, but it would be even better to just use > simple_read_from_buffer in this function, which takes care of > a lot the other complexities as well. Like this? (Sorry, untested.) Signed-off-by: Nicolas Kaiser --- obsoletes patch "dma/coh901318: fix copy_to_user error path" drivers/dma/coh901318.c | 12 +----------- 1 files changed, 1 insertions(+), 11 deletions(-) diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c index ae2b871..e7d0f06 100644 --- a/drivers/dma/coh901318.c +++ b/drivers/dma/coh901318.c @@ -133,17 +133,7 @@ static int coh901318_debugfs_read(struct file *file, char __user *buf, tmp += sprintf(tmp, "Pool alloc nbr %d\n", pool_count); dev_size = tmp - dev_buf; - /* No more to read if offset != 0 */ - if (*f_pos > dev_size) - goto out; - - if (count > dev_size - *f_pos) - count = dev_size - *f_pos; - - if (copy_to_user(buf, dev_buf + *f_pos, count)) - ret = -EINVAL; - ret = count; - *f_pos += count; + ret = simple_read_from_buffer(buf, count, f_pos, dev_buf, dev_size); out: kfree(dev_buf); -- 1.7.2.2