lkml.org 
[lkml]   [2015]   [Mar]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] char: xillybus: Don't return -EFAULT on user-triggered flush
Date
The API allows the application to flush a host-to-FPGA stream by calling
write() with the data count set to zero. Before this patch, copy_from_user()
was called with a non-zero byte count, which possibly made it attempt to read
from unmapped user memory. Such attempts caused the driver to return -EFAULT
instead of 0, even though the desired operation went through fine.

This patch ensures the driver returns 0 on a successful flush.

Signed-off-by: Eli Billauer <eli.billauer@gmail.com>
---
drivers/char/xillybus/xillybus_core.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/char/xillybus/xillybus_core.c b/drivers/char/xillybus/xillybus_core.c
index b827fa0..77d6c12 100644
--- a/drivers/char/xillybus/xillybus_core.c
+++ b/drivers/char/xillybus/xillybus_core.c
@@ -1237,6 +1237,8 @@ static ssize_t xillybus_write(struct file *filp, const char __user *userbuf,
unsigned char *tail;
int i;

+ howmany = 0;
+
end_offset_plus1 = bufpos >>
channel->log2_element_size;

--
1.7.2.3


\
 
 \ /
  Last update: 2015-03-27 10:21    [W:0.042 / U:0.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site