bsg: Fix sense buffer bug in SG_IO
When submitting requests via SG_IO, which does a sync io, a
bsg_command is not allocated. So an in-Kernel sense_buffer was not
set. However when calling blk_execute_rq() with no sense buffer
one is provided from the stack. Now bsg at blk_complete_sgv4_hdr_rq()
would check if rq->sense_len and a sense was requested by sg_io_v4
the rq->sense was copy_user() back, but by now it is already mangled
stack memory.
I have fixed that by forcing a sense_buffer when calling bsg_map_hdr().
The bsg_command->sense is provided in the write/read path like before,
and on-the-stack buffer is provided when doing SG_IO.
I have also fixed a dprintk message to print rq->errors in hex because
of the scsi bit-field use of this member. For other block devices it
does not matter anyway.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/bsg.c b/block/bsg.c
index d414bb5..0ce8806 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -244,7 +244,8 @@
* map sg_io_v4 to a request.
*/
static struct request *
-bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm)
+bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm,
+ u8 *sense)
{
struct request_queue *q = bd->queue;
struct request *rq, *next_rq = NULL;
@@ -306,6 +307,10 @@
if (ret)
goto out;
}
+
+ rq->sense = sense;
+ rq->sense_len = 0;
+
return rq;
out:
if (rq->cmd != rq->__cmd)
@@ -348,9 +353,6 @@
static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
struct bsg_command *bc, struct request *rq)
{
- rq->sense = bc->sense;
- rq->sense_len = 0;
-
/*
* add bc command to busy queue and submit rq for io
*/
@@ -419,7 +421,7 @@
{
int ret = 0;
- dprintk("rq %p bio %p %u\n", rq, bio, rq->errors);
+ dprintk("rq %p bio %p 0x%x\n", rq, bio, rq->errors);
/*
* fill in all the output members
*/
@@ -635,7 +637,7 @@
/*
* get a request, fill in the blanks, and add to request queue
*/
- rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm);
+ rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm, bc->sense);
if (IS_ERR(rq)) {
ret = PTR_ERR(rq);
rq = NULL;
@@ -922,11 +924,12 @@
struct request *rq;
struct bio *bio, *bidi_bio = NULL;
struct sg_io_v4 hdr;
+ u8 sense[SCSI_SENSE_BUFFERSIZE];
if (copy_from_user(&hdr, uarg, sizeof(hdr)))
return -EFAULT;
- rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE);
+ rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE, sense);
if (IS_ERR(rq))
return PTR_ERR(rq);