lkml.org 
[lkml]   [2019]   [Oct]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[Patch v4 1/2] linux/build_bug.h: Change type to int
Date
Having BUILD_BUG_ON_ZERO produce a value of type size_t leads to awkward
casts in cases where the result needs to be signed, or of smaller type
than size_t. To avoid this, cast the value to int instead and rely on
implicit type conversions when a larger or unsigned type is needed.

Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
---
Changes in v4:
- Added Kees and Masahiros reviewed-by tags.
Changes in v3:
- This patch is new in v3

include/linux/build_bug.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/build_bug.h b/include/linux/build_bug.h
index 0fe5426f2bdc..e3a0be2c90ad 100644
--- a/include/linux/build_bug.h
+++ b/include/linux/build_bug.h
@@ -9,11 +9,11 @@
#else /* __CHECKER__ */
/*
* Force a compilation error if condition is true, but also produce a
- * result (of value 0 and type size_t), so the expression can be used
+ * result (of value 0 and type int), so the expression can be used
* e.g. in a structure initializer (or where-ever else comma expressions
* aren't permitted).
*/
-#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:(-!!(e)); }))
+#define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
#endif /* __CHECKER__ */

/* Force a compilation error if a constant expression is not a power of 2 */
--
2.23.0
\
 
 \ /
  Last update: 2019-10-09 23:46    [W:0.182 / U:66.684 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site