From 81409e9e28058811c9ea865345e1753f8f677e44 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 31 Aug 2016 16:04:21 -0700 Subject: [PATCH] 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 --- arch/ia64/include/asm/uaccess.h | 12 ++++-------- arch/powerpc/include/asm/uaccess.h | 19 +++++++------------ arch/sparc/include/asm/uaccess_32.h | 9 +++------ arch/sparc/include/asm/uaccess_64.h | 7 +++---- include/linux/thread_info.h | 3 ++- 5 files changed, 19 insertions(+), 31 deletions(-) diff --git a/arch/ia64/include/asm/uaccess.h b/arch/ia64/include/asm/uaccess.h index 465c70982f40..0472927ebb9b 100644 --- a/arch/ia64/include/asm/uaccess.h +++ b/arch/ia64/include/asm/uaccess.h @@ -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; \ diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index c1dc6c14deb8..f1e382498bbb 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -311,14 +311,12 @@ static inline unsigned long copy_from_user(void *to, unsigned long over; if (access_ok(VERIFY_READ, from, n)) { - if (!__builtin_constant_p(n)) - check_object_size(to, n, false); + check_object_size(to, n, false); return __copy_tofrom_user((__force void __user *)to, from, n); } if ((unsigned long)from < TASK_SIZE) { over = (unsigned long)from + n - TASK_SIZE; - if (!__builtin_constant_p(n - over)) - check_object_size(to, n - over, false); + check_object_size(to, n - over, false); return __copy_tofrom_user((__force void __user *)to, from, n - over) + over; } @@ -331,14 +329,12 @@ static inline unsigned long copy_to_user(void __user *to, unsigned long over; if (access_ok(VERIFY_WRITE, to, n)) { - if (!__builtin_constant_p(n)) - check_object_size(from, n, true); + check_object_size(from, n, true); return __copy_tofrom_user(to, (__force void __user *)from, n); } if ((unsigned long)to < TASK_SIZE) { over = (unsigned long)to + n - TASK_SIZE; - if (!__builtin_constant_p(n)) - check_object_size(from, n - over, true); + check_object_size(from, n - over, true); return __copy_tofrom_user(to, (__force void __user *)from, n - over) + over; } @@ -383,8 +379,7 @@ static inline unsigned long __copy_from_user_inatomic(void *to, return 0; } - if (!__builtin_constant_p(n)) - check_object_size(to, n, false); + check_object_size(to, n, false); return __copy_tofrom_user((__force void __user *)to, from, n); } @@ -412,8 +407,8 @@ static inline unsigned long __copy_to_user_inatomic(void __user *to, if (ret == 0) return 0; } - if (!__builtin_constant_p(n)) - check_object_size(from, n, true); + + check_object_size(from, n, true); return __copy_tofrom_user(to, (__force const void __user *)from, n); } diff --git a/arch/sparc/include/asm/uaccess_32.h b/arch/sparc/include/asm/uaccess_32.h index 341a5a133f48..e722c510bb1b 100644 --- a/arch/sparc/include/asm/uaccess_32.h +++ b/arch/sparc/include/asm/uaccess_32.h @@ -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; diff --git a/arch/sparc/include/asm/uaccess_64.h b/arch/sparc/include/asm/uaccess_64.h index 8bda94fab8e8..37a315d0ddd4 100644 --- a/arch/sparc/include/asm/uaccess_64.h +++ b/arch/sparc/include/asm/uaccess_64.h @@ -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); diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h index cbd8990e2e77..10c9e601398b 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -121,7 +121,8 @@ extern void __check_object_size(const void *ptr, unsigned long n, static inline void check_object_size(const void *ptr, unsigned long n, bool to_user) { - __check_object_size(ptr, n, to_user); + if (!__builtin_constant_p(n)) + __check_object_size(ptr, n, to_user); } #else static inline void check_object_size(const void *ptr, unsigned long n, -- 2.20.1