copy_{from,to}_user(): move kasan checks and might_fault() out-of-line
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 201418d..e573288 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -109,8 +109,11 @@ static inline 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;
@@ -124,8 +127,11 @@ _copy_from_user(void *, const void __user *, unsigned long);
static inline unsigned long
_copy_to_user(void __user *to, const void *from, unsigned long n)
{
- if (access_ok(VERIFY_WRITE, to, n))
+ might_fault();
+ if (access_ok(VERIFY_WRITE, to, n)) {
+ kasan_check_read(from, n);
n = raw_copy_to_user(to, from, n);
+ }
return n;
}
#else
@@ -146,9 +152,6 @@ copy_from_user(void *to, const void __user *from, unsigned long n)
{
int sz = __compiletime_object_size(to);
- might_fault();
- kasan_check_write(to, n);
-
if (likely(sz < 0 || sz >= n)) {
check_object_size(to, n, false);
n = _copy_from_user(to, from, n);
@@ -165,9 +168,6 @@ copy_to_user(void __user *to, const void *from, unsigned long n)
{
int sz = __compiletime_object_size(from);
- kasan_check_read(from, n);
- might_fault();
-
if (likely(sz < 0 || sz >= n)) {
check_object_size(from, n, true);
n = _copy_to_user(to, from, n);
diff --git a/lib/usercopy.c b/lib/usercopy.c
index 1b6010a..f5d9f08 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);