aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--block/blk-map.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/block/blk-map.c b/block/blk-map.c
index 813011ef827..ddd96fb11a7 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -269,6 +269,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
269 int reading = rq_data_dir(rq) == READ; 269 int reading = rq_data_dir(rq) == READ;
270 int do_copy = 0; 270 int do_copy = 0;
271 struct bio *bio; 271 struct bio *bio;
272 unsigned long stack_mask = ~(THREAD_SIZE - 1);
272 273
273 if (len > (q->max_hw_sectors << 9)) 274 if (len > (q->max_hw_sectors << 9))
274 return -EINVAL; 275 return -EINVAL;
@@ -279,6 +280,10 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
279 alignment = queue_dma_alignment(q) | q->dma_pad_mask; 280 alignment = queue_dma_alignment(q) | q->dma_pad_mask;
280 do_copy = ((kaddr & alignment) || (len & alignment)); 281 do_copy = ((kaddr & alignment) || (len & alignment));
281 282
283 if (!((kaddr & stack_mask) ^
284 ((unsigned long)current->stack & stack_mask)))
285 do_copy = 1;
286
282 if (do_copy) 287 if (do_copy)
283 bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading); 288 bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
284 else 289 else