[PATCH 01/22] block: Use rw_copy_check_uvector()

Kent Overstreet
2013-08-07T22:03:05Z

No need for silly open coding - and struct sg_iovec has exactly the same
layout as struct iovec...

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
---
block/scsi_ioctl.c | 39 ++++++++++-----------------------------
1 file changed, 10 insertions(+), 29 deletions(-)

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index a5ffcc9..625e3e4 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -286,7 +286,8 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
struct sg_io_hdr *hdr, fmode_t mode)
{
unsigned long start_time;
- int writing = 0, ret = 0;
+ ssize_t ret = 0;
+ int writing = 0;
struct request *rq;
char sense[SCSI_SENSE_BUFFERSIZE];
struct bio *bio;
@@ -321,37 +322,16 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
}

if (hdr->iovec_count) {
- const int size = sizeof(struct sg_iovec) * hdr->iovec_count;
size_t iov_data_len;
- struct sg_iovec *sg_iov;
struct iovec *iov;
- int i;

- sg_iov = kmalloc(size, GFP_KERNEL);
- if (!sg_iov) {
- ret = -ENOMEM;
+ ret = rw_copy_check_uvector(-1, hdr->dxferp, hdr->iovec_count,
+ 0, NULL, &iov);
+ if (ret < 0)
goto out;
- }
-
- if (copy_from_user(sg_iov, hdr->dxferp, size)) {
- kfree(sg_iov);
- ret = -EFAULT;
- goto out;
- }

- /*
- * Sum up the vecs, making sure they don't overflow
- */
- iov = (struct iovec *) sg_iov;
- iov_data_len = 0;
- for (i = 0; i < hdr->iovec_count; i++) {
- if (iov_data_len + iov[i].iov_len < iov_data_len) {
- kfree(sg_iov);
- ret = -EINVAL;
- goto out;
- }
- iov_data_len += iov[i].iov_len;
- }
+ iov_data_len = ret;
+ ret = 0;

/* SG_IO howto says that the shorter of the two wins */
if (hdr->dxfer_len < iov_data_len) {
@@ -361,9 +341,10 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
iov_data_len = hdr->dxfer_len;
}

- ret = blk_rq_map_user_iov(q, rq, NULL, sg_iov, hdr->iovec_count,
+ ret = blk_rq_map_user_iov(q, rq, NULL, (struct sg_iovec *) iov,
+ hdr->iovec_count,
iov_data_len, GFP_KERNEL);
- kfree(sg_iov);
+ kfree(iov);
} else if (hdr->dxfer_len)
ret = blk_rq_map_user(q, rq, NULL, hdr->dxferp, hdr->dxfer_len,
GFP_KERNEL);
--
1.8.4.rc1