Drivers: hv: util: make struct hv_do_fcopy match Hyper-V host messages
authorVitaly Kuznetsov <vkuznets@redhat.com>
Fri, 24 Oct 2014 10:20:27 +0000 (12:20 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 7 Nov 2014 18:21:44 +0000 (10:21 -0800)
An attempt to fix fcopy on i586 (bc5a5b0 Drivers: hv: util: Properly pack the data
for file copy functionality) led to a regression on x86_64 (and actually didn't fix
i586 breakage). Fcopy messages from Hyper-V host come in the following format:

struct do_fcopy_hdr   |   36 bytes
0000                  |    4 bytes
offset                |    8 bytes
size                  |    4 bytes
data                  | 6144 bytes

On x86_64 struct hv_do_fcopy matched this format without ' __attribute__((packed))'
and on i586 adding ' __attribute__((packed))' to it doesn't change anything. Keep
the structure packed and add padding to match re reality. Tested both i586 and x86_64
on Hyper-V Server 2012 R2.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
include/uapi/linux/hyperv.h

index 0a8e6badb29bcf05f9a1c968a9c2e2c2d271df1e..bb1cb73c927ae78c84e3ea5a7f253be6040cfed7 100644 (file)
@@ -134,6 +134,7 @@ struct hv_start_fcopy {
 
 struct hv_do_fcopy {
        struct hv_fcopy_hdr hdr;
+       __u32   pad;
        __u64   offset;
        __u32   size;
        __u8    data[DATA_FRAGMENT];