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

@@ -241,8 +241,7 @@ extern unsigned long __must_check __copy_user (void __user *to, const void __use
static inline unsigned long
__copy_to_user (void __user *to, const void *from, unsigned long count)
{
if (!__builtin_constant_p(count))
check_object_size(from, count, true);
check_object_size(from, count, true);
return __copy_user(to, (__force void __user *) from, count);
}
@@ -250,8 +249,7 @@ __copy_to_user (void __user *to, const void *from, unsigned long count)
static inline unsigned long
__copy_from_user (void *to, const void __user *from, unsigned long count)
{
if (!__builtin_constant_p(count))
check_object_size(to, count, false);
check_object_size(to, count, false);
return __copy_user((__force void __user *) to, from, count);
}
@@ -265,8 +263,7 @@ __copy_from_user (void *to, const void __user *from, unsigned long count)
long __cu_len = (n); \
\
if (__access_ok(__cu_to, __cu_len, get_fs())) { \
if (!__builtin_constant_p(n)) \
check_object_size(__cu_from, __cu_len, true); \
check_object_size(__cu_from, __cu_len, true); \
__cu_len = __copy_user(__cu_to, (__force void __user *) __cu_from, __cu_len); \
} \
__cu_len; \
@@ -280,8 +277,7 @@ __copy_from_user (void *to, const void __user *from, unsigned long count)
\
__chk_user_ptr(__cu_from); \
if (__access_ok(__cu_from, __cu_len, get_fs())) { \
if (!__builtin_constant_p(n)) \
check_object_size(__cu_to, __cu_len, false); \
check_object_size(__cu_to, __cu_len, false); \
__cu_len = __copy_user((__force void __user *) __cu_to, __cu_from, __cu_len); \
} \
__cu_len; \