diff options
| -rw-r--r-- | block/bio.c | 42 | ||||
| -rw-r--r-- | include/linux/uio.h | 2 | ||||
| -rw-r--r-- | lib/iovec.c | 30 |
3 files changed, 38 insertions, 36 deletions
diff --git a/block/bio.c b/block/bio.c index 8a5d8239ecb8..bdb3896d2b58 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1088,23 +1088,9 @@ struct bio *bio_copy_user_iov(struct request_queue *q, unsigned int len; unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0; - for (i = 0; i < iter->nr_segs; i++) { - unsigned long uaddr; - unsigned long end; - unsigned long start; - - uaddr = (unsigned long) iter->iov[i].iov_base; - end = (uaddr + iter->iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; - start = uaddr >> PAGE_SHIFT; - - /* - * Overflow, abort - */ - if (end < start) - return ERR_PTR(-EINVAL); - - nr_pages += end - start; - } + nr_pages = iov_count_pages(iter, 0); + if (nr_pages < 0) + return ERR_PTR(nr_pages); if (offset) nr_pages++; @@ -1234,25 +1220,9 @@ static struct bio *__bio_map_user_iov(struct request_queue *q, struct iov_iter i; struct iovec iov; - iov_for_each(iov, i, *iter) { - unsigned long uaddr = (unsigned long) iov.iov_base; - unsigned long len = iov.iov_len; - unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; - unsigned long start = uaddr >> PAGE_SHIFT; - - /* - * Overflow, abort - */ - if (end < start) - return ERR_PTR(-EINVAL); - - nr_pages += end - start; - /* - * buffer must be aligned to at least hardsector size for now - */ - if (uaddr & queue_dma_alignment(q)) - return ERR_PTR(-EINVAL); - } + nr_pages = iov_count_pages(iter, queue_dma_alignment(q)); + if (nr_pages < 0) + return ERR_PTR(nr_pages); if (!nr_pages) return ERR_PTR(-EINVAL); diff --git a/include/linux/uio.h b/include/linux/uio.h index e2231e47cec1..c08110705118 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -71,6 +71,8 @@ static inline struct iovec iov_iter_iovec(const struct iov_iter *iter) unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to); +int iov_count_pages(const struct iov_iter *iter, unsigned align); + size_t iov_iter_copy_from_user_atomic(struct page *page, struct iov_iter *i, unsigned long offset, size_t bytes); void iov_iter_advance(struct iov_iter *i, size_t bytes); diff --git a/lib/iovec.c b/lib/iovec.c index 454baa88bf27..fa2c050dc137 100644 --- a/lib/iovec.c +++ b/lib/iovec.c @@ -1,5 +1,7 @@ #include <linux/uaccess.h> #include <linux/export.h> +#include <linux/fs.h> +#include <linux/mm.h> #include <linux/uio.h> /* @@ -51,3 +53,31 @@ int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len) return 0; } EXPORT_SYMBOL(memcpy_toiovec); + +int iov_count_pages(const struct iov_iter *iter, unsigned align) +{ + struct iov_iter i = *iter; + int nr_pages = 0; + + while (iov_iter_count(&i)) { + unsigned long uaddr = (unsigned long) i.iov->iov_base + + i.iov_offset; + unsigned long len = i.iov->iov_len - i.iov_offset; + + if ((uaddr & align) || (len & align)) + return -EINVAL; + + /* + * Overflow, abort + */ + if (uaddr + len < uaddr) + return -EINVAL; + + nr_pages += DIV_ROUND_UP(len + offset_in_page(uaddr), + PAGE_SIZE); + iov_iter_advance(&i, len); + } + + return nr_pages; +} +EXPORT_SYMBOL(iov_count_pages); |