scatterlist: sg_set_buf() argument must be in linear mapping

Add a check behind CONFIG_DEBUG_SG to verify this.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index 5951e3f38878..26806775b11b 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -111,6 +111,9 @@ static inline struct page *sg_page(struct scatterlist *sg)
 static inline void sg_set_buf(struct scatterlist *sg, const void *buf,
                               unsigned int buflen)
 {
+#ifdef CONFIG_DEBUG_SG
+        BUG_ON(!virt_addr_valid(buf));
+#endif
         sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));
 }