From: FUJITA Tomonori Date: Tue, 2 Sep 2008 07:20:20 +0000 (+0900) Subject: sg: set dxferp to NULL for READ with the older SG interface X-Git-Tag: firefly_0821_release~17841^2~56 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=fad7f01e61bf737fe8a3740d803f000db57ecac6;p=firefly-linux-kernel-4.4.55.git sg: set dxferp to NULL for READ with the older SG interface With the older SG interface, we don't know a user-space address to trasfer data when executing a SCSI command. So we can't pass a user-space address to blk_rq_map_user. This patch fixes sg to pass a NULL user-space address to blk_rq_map_user so that it just sets up a request and bios with page frames propely without data transfer. Signed-off-by: FUJITA Tomonori Signed-off-by: Jens Axboe --- diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index ed69292babde..50c07bca727d 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -615,7 +615,10 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) else hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE; hp->dxfer_len = mxsize; - hp->dxferp = (char __user *)buf + cmd_size; + if (hp->dxfer_direction == SG_DXFER_TO_DEV) + hp->dxferp = (char __user *)buf + cmd_size; + else + hp->dxferp = NULL; hp->sbp = NULL; hp->timeout = old_hdr.reply_len; /* structure abuse ... */ hp->flags = input_size; /* structure abuse ... */