int reading = rq_data_dir(rq) == READ;
int do_copy = 0;
struct bio *bio;
+ unsigned long stack_mask = ~(THREAD_SIZE - 1);
if (len > (q->max_hw_sectors << 9))
return -EINVAL;
alignment = queue_dma_alignment(q) | q->dma_pad_mask;
do_copy = ((kaddr & alignment) || (len & alignment));
+ if (!((kaddr & stack_mask) ^
+ ((unsigned long)current->stack & stack_mask)))
+ do_copy = 1;
+
if (do_copy)
bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
else