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author | Al Viro <viro@zeniv.linux.org.uk> | 2016-09-17 18:02:44 -0400 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2016-09-27 18:12:24 -0400 |
commit | 4bce9f6ee8f84fdf333d0fd7fcf7f0d8c7cce7fa (patch) | |
tree | a5d3f51f67b05e37d3de3ed9201794924b66efc2 /include/linux/pagemap.h | |
parent | 08895a8b6b06ed2323cd97a36ee40a116b3db8ed (diff) | |
download | linux-4bce9f6ee8f84fdf333d0fd7fcf7f0d8c7cce7fa.tar.gz linux-4bce9f6ee8f84fdf333d0fd7fcf7f0d8c7cce7fa.tar.bz2 linux-4bce9f6ee8f84fdf333d0fd7fcf7f0d8c7cce7fa.zip |
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>
Diffstat (limited to 'include/linux/pagemap.h')
-rw-r--r-- | include/linux/pagemap.h | 54 |
1 files changed, 2 insertions, 52 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 01e84436cddf..cb2e1d06d2e9 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -518,59 +518,10 @@ void page_endio(struct page *page, bool is_write, int err); 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 @@ static inline int fault_in_multipages_writeable(char __user *uaddr, int size) 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; |