From: Christoph Hellwig <hch@xxxxxx> Subject: 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/20190520055731.24538-5-hch@xxxxxx Signed-off-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Sami Tolvanen <samitolvanen@xxxxxxxxxx> Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/9p/vfs_addr.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/fs/9p/vfs_addr.c~9p-pass-the-correct-prototype-to-read_cache_page +++ a/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 fil 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; } _
