9p: pass the correct prototype to read_cache_page

Fix the callback 9p passes to read_cache_page to actually have the proper type expected. Casting around function pointers can easily hide typing bugs, and defeats control flow protection. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Christoph Hellwig <[email protected]> Reviewed-by: Kees Cook <[email protected]> Cc: Sami Tolvanen <[email protected]> Cc: Nick Desaulniers <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
vieko · Jul 12, 2019 · f053cbd · f053cbd
1 parent 265de8c
commit f053cbd
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
@@ -35,8 +35,9 @@
  * @page: structure to page
  *
  */
-static int v9fs_fid_readpage(struct p9_fid *fid, struct page *page)
+static int v9fs_fid_readpage(void *data, struct page *page)
 {
+	struct p9_fid *fid = data;
 	struct inode *inode = page->mapping->host;
 	struct bio_vec bvec = {.bv_page = page, .bv_len = PAGE_SIZE};
 	struct iov_iter to;
@@ -107,7 +108,8 @@ static int v9fs_vfs_readpages(struct file *filp, struct address_space *mapping,
 	if (ret == 0)
 		return ret;
 
-	ret = read_cache_pages(mapping, pages, (void *)v9fs_vfs_readpage, filp);
+	ret = read_cache_pages(mapping, pages, v9fs_fid_readpage,
+			filp->private_data);
 	p9_debug(P9_DEBUG_VFS, "  = %d\n", ret);
 	return ret;
 }