get rid of separate multipage fault-in primitives
* the only remaining callers of "short" fault-ins are just as happy with generic
variants (both in lib/iov_iter.c); switch them to multipage variants, kill the
"short" ones
* rename the multipage variants to now available plain ones.
* get rid of compat macro defining iov_iter_fault_in_multipage_readable by
expanding it in its only user.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 01e8443..cb2e1d0 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -518,59 +518,10 @@
extern void add_page_wait_queue(struct page *page, wait_queue_t *waiter);
/*
- * Fault one or two userspace pages into pagetables.
- * Return -EINVAL if more than two pages would be needed.
- * Return non-zero on a fault.
+ * Fault everything in given userspace address range in.
*/
static inline int fault_in_pages_writeable(char __user *uaddr, int size)
{
- int span, ret;
-
- if (unlikely(size == 0))
- return 0;
-
- span = offset_in_page(uaddr) + size;
- if (span > 2 * PAGE_SIZE)
- return -EINVAL;
- /*
- * Writing zeroes into userspace here is OK, because we know that if
- * the zero gets there, we'll be overwriting it.
- */
- ret = __put_user(0, uaddr);
- if (ret == 0 && span > PAGE_SIZE)
- ret = __put_user(0, uaddr + size - 1);
- return ret;
-}
-
-static inline int fault_in_pages_readable(const char __user *uaddr, int size)
-{
- volatile char c;
- int ret;
-
- if (unlikely(size == 0))
- return 0;
-
- ret = __get_user(c, uaddr);
- if (ret == 0) {
- const char __user *end = uaddr + size - 1;
-
- if (((unsigned long)uaddr & PAGE_MASK) !=
- ((unsigned long)end & PAGE_MASK)) {
- ret = __get_user(c, end);
- (void)c;
- }
- }
- return ret;
-}
-
-/*
- * Multipage variants of the above prefault helpers, useful if more than
- * PAGE_SIZE of data needs to be prefaulted. These are separate from the above
- * functions (which only handle up to PAGE_SIZE) to avoid clobbering the
- * filemap.c hotpaths.
- */
-static inline int fault_in_multipages_writeable(char __user *uaddr, int size)
-{
char __user *end = uaddr + size - 1;
if (unlikely(size == 0))
@@ -596,8 +547,7 @@
return 0;
}
-static inline int fault_in_multipages_readable(const char __user *uaddr,
- int size)
+static inline int fault_in_pages_readable(const char __user *uaddr, int size)
{
volatile char c;
const char __user *end = uaddr + size - 1;
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 75b4aaf..7709f8d 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -76,7 +76,6 @@
struct iov_iter *i, unsigned long offset, size_t bytes);
void iov_iter_advance(struct iov_iter *i, size_t bytes);
int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);
-#define iov_iter_fault_in_multipages_readable iov_iter_fault_in_readable
size_t iov_iter_single_seg_count(const struct iov_iter *i);
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i);