From c80d92fbb67b2c80b8eeb8759ee79d676eb33520 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@chromium.org>
Date: Thu, 17 Jun 2021 22:48:05 -0700
Subject: compiler_types.h: Remove __compiletime_object_size()

Since all compilers support __builtin_object_size(), and there is only
one user of __compiletime_object_size, remove it to avoid the needless
indirection. This lets Clang reason about check_copy_size() correctly.

Link: https://github.com/ClangBuiltLinux/linux/issues/1179
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marco Elver <elver@google.com>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Gabriel Krisman Bertazi <krisman@collabora.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/thread_info.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'include/linux/thread_info.h')

diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index 0999f6317978..ad0c4e041030 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -203,7 +203,7 @@ static inline void copy_overflow(int size, unsigned long count)
 static __always_inline __must_check bool
 check_copy_size(const void *addr, size_t bytes, bool is_source)
 {
-	int sz = __compiletime_object_size(addr);
+	int sz = __builtin_object_size(addr, 0);
 	if (unlikely(sz >= 0 && sz < bytes)) {
 		if (!__builtin_constant_p(bytes))
 			copy_overflow(sz, bytes);
-- 
cgit