usercopy: fold builtin_const check into inline function

Instead of having each caller of check_object_size() need to remember to
check for a const size parameter, move the check into check_object_size()
itself. This actually matches the original implementation in PaX, though
this commit cleans up the now-redundant builtin_const() calls in the
various architectures.

Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
Kees Cook
2016-08-31 16:04:21 -07:00
parent e6971009a9
commit 81409e9e28
5 changed files with 19 additions and 31 deletions

View File

@@ -249,8 +249,7 @@ unsigned long __copy_user(void __user *to, const void __user *from, unsigned lon
static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n)
{
if (n && __access_ok((unsigned long) to, n)) {
if (!__builtin_constant_p(n))
check_object_size(from, n, true);
check_object_size(from, n, true);
return __copy_user(to, (__force void __user *) from, n);
} else
return n;
@@ -258,16 +257,14 @@ static inline unsigned long copy_to_user(void __user *to, const void *from, unsi
static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
{
if (!__builtin_constant_p(n))
check_object_size(from, n, true);
check_object_size(from, n, true);
return __copy_user(to, (__force void __user *) from, n);
}
static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n)
{
if (n && __access_ok((unsigned long) from, n)) {
if (!__builtin_constant_p(n))
check_object_size(to, n, false);
check_object_size(to, n, false);
return __copy_user((__force void __user *) to, from, n);
} else
return n;

View File

@@ -212,8 +212,7 @@ copy_from_user(void *to, const void __user *from, unsigned long size)
{
unsigned long ret;
if (!__builtin_constant_p(size))
check_object_size(to, size, false);
check_object_size(to, size, false);
ret = ___copy_from_user(to, from, size);
if (unlikely(ret))
@@ -233,8 +232,8 @@ copy_to_user(void __user *to, const void *from, unsigned long size)
{
unsigned long ret;
if (!__builtin_constant_p(size))
check_object_size(from, size, true);
check_object_size(from, size, true);
ret = ___copy_to_user(to, from, size);
if (unlikely(ret))
ret = copy_to_user_fixup(to, from, size);