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authorEli Billauer <eli.billauer@gmail.com>2015-03-27 11:56:06 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-04-03 17:15:30 +0300
commit127af8828518074ab24e9b5678229513d198d832 (patch)
treea90aa2b61478e17ea53de4caba0874d13cf87b31 /drivers/char/xillybus
parentbe29bc2eaa5360537df422a237c889dc493492f4 (diff)
downloadlinux-127af8828518074ab24e9b5678229513d198d832.tar.xz
char: xillybus: Don't return -EFAULT on user-triggered flush
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/char/xillybus')
-rw-r--r--drivers/char/xillybus/xillybus_core.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/char/xillybus/xillybus_core.c b/drivers/char/xillybus/xillybus_core.c
index b827fa095f1b..77d6c127e691 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;