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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>
This commit is contained in:
Boaz Harrosh 2009-02-03 07:47:29 +01:00 committed by Jens Axboe
parent 5955c7a2cf
commit c1c201200a
1 changed files with 10 additions and 7 deletions
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17
block/bsg.c
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@ -244,7 +244,8 @@ bsg_validate_sgv4_hdr(struct request_queue *q, struct sg_io_v4 *hdr, int *rw)
* 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 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm)
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_rq_end_io(struct request *rq, int uptodate)
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 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
{
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 @@ static int __bsg_write(struct bsg_device *bd, const char __user *buf,
/*
* 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 @@ static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
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);