libata: clear PIO pad area

ata_sff_data_xfer[32]() use pad area if the transfer size isn't
multiple of transfer size; however, this area wasn't cleared and
garbage data in pad area could be transferred to the device.  Make
sure the pad area is cleared.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Lei Ming <tom.leiming@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index c24127d..2487ea7 100644 (file)
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -569,7 +569,7 @@ unsigned int ata_sff_data_xfer(struct ata_device *dev, unsigned char *buf,
 
        /* Transfer trailing byte, if any. */
        if (unlikely(buflen & 0x01)) {
-               unsigned char pad[2];
+               unsigned char pad[2] = { };
 
                /* Point buf to the tail of buffer */
                buf += buflen - 1;
@@ -628,7 +628,7 @@ unsigned int ata_sff_data_xfer32(struct ata_device *dev, unsigned char *buf,
 
        /* Transfer trailing bytes, if any */
        if (unlikely(slop)) {
-               unsigned char pad[4];
+               unsigned char pad[4] = { };
 
                /* Point buf to the tail of buffer */
                buf += buflen - slop;