[PATCH 3/5] udmabuf: fix vmap_udmabuf error page set

[Huan Yang]

Currently vmap_udmabuf set page's array by each folio.
But, ubuf->folios is only contain's the folio's head page.

That mean we repeatedly mapped the folio head page to the vmalloc area.

This patch fix it, set each folio's page correct, so that pages array
contains right page, and then map into vmalloc area

Signed-off-by: Huan Yang <link at vivo.com>
---
 drivers/dma-buf/udmabuf.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index a915714c5dce..7ed532342d7f 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -77,18 +77,27 @@ static int mmap_udmabuf(struct dma_buf *buf, struct vm_area_struct *vma)
 static int vmap_udmabuf(struct dma_buf *buf, struct iosys_map *map)
 {
 	struct udmabuf *ubuf = buf->priv;
-	struct page **pages;
+	struct page **pages, **tmp;
+	struct sg_table *sg = ubuf->sg;
+	struct sg_page_iter piter;
 	void *vaddr;
-	pgoff_t pg;
 
 	dma_resv_assert_held(buf->resv);
 
+	if (!sg) {
+		sg = get_sg_table(NULL, buf, 0);
+		if (IS_ERR(sg))
+			return PTR_ERR(sg);
+		ubuf->sg = sg;
+	}
+
 	pages = kvmalloc_array(ubuf->pagecount, sizeof(*pages), GFP_KERNEL);
 	if (!pages)
 		return -ENOMEM;
+	tmp = pages;
 
-	for (pg = 0; pg < ubuf->pagecount; pg++)
-		pages[pg] = &ubuf->folios[pg]->page;
+	for_each_sgtable_page(sg, &piter, 0)
+		*tmp++ = sg_page_iter_page(&piter);
 
 	vaddr = vm_map_ram(pages, ubuf->pagecount, -1);
 	kvfree(pages);
-- 
2.45.2