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| author |   Eli Billauer <eli.billauer@gmail.com> | 2015-03-27 11:56:06 +0300 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-04-03 16:15:30 +0200 |
| commit | 127af8828518074ab24e9b5678229513d198d832 (patch) | |
| tree | a90aa2b61478e17ea53de4caba0874d13cf87b31 /drivers/char/xillybus | |
| parent | mic: drop pci_msi_off call on probe (diff) | |
| download | wireguard-linux-127af8828518074ab24e9b5678229513d198d832.tar.xz wireguard-linux-127af8828518074ab24e9b5678229513d198d832.zip | |
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.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 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; |