copy_{from,to}_user(): move kasan checks and might_fault() out-of-line

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 8 insertions, 2 deletions

diff --git a/lib/usercopy.c b/lib/usercopy.c
index 1b6010a3beb8..f5d9f08ee032 100644
--- a/lib/usercopy.c
+++ b/lib/usercopy.c
@@ -6,8 +6,11 @@
 unsigned long _copy_from_user(void *to, const void __user *from, unsigned long n)
 {
         unsigned long res = n;
-        if (likely(access_ok(VERIFY_READ, from, n)))
+        might_fault();
+        if (likely(access_ok(VERIFY_READ, from, n))) {
+                kasan_check_write(to, n);
                 res = raw_copy_from_user(to, from, n);
+        }
         if (unlikely(res))
                 memset(to + (n - res), 0, res);
         return res;
@@ -18,8 +21,11 @@ EXPORT_SYMBOL(_copy_from_user);
 #ifndef INLINE_COPY_TO_USER
 unsigned long _copy_to_user(void *to, const void __user *from, unsigned long n)
 {
-        if (likely(access_ok(VERIFY_WRITE, to, n)))
+        might_fault();
+        if (likely(access_ok(VERIFY_WRITE, to, n))) {
+                kasan_check_read(from, n);
                 n = raw_copy_to_user(to, from, n);
+        }
         return n;
 }
 EXPORT_SYMBOL(_copy_to_user);