2021-04-01 18:53:43

by Keith Busch

[permalink] [raw]
Subject: [PATCH] overflow: improve check_shl_overflow comment

A 'false' return means the value was safely set, so the comment should
say 'true' for when it is not considered safe.

Cc: Jason Gunthorpe <[email protected]>
Cc: Kees Cook <[email protected]>
Signed-off-by: Keith Busch <[email protected]>
---
include/linux/overflow.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/overflow.h b/include/linux/overflow.h
index ef74051d5cfed..0f12345c21fb5 100644
--- a/include/linux/overflow.h
+++ b/include/linux/overflow.h
@@ -235,7 +235,7 @@ static inline bool __must_check __must_check_overflow(bool overflow)
* - 'a << s' sets the sign bit, if any, in '*d'.
*
* '*d' will hold the results of the attempted shift, but is not
- * considered "safe for use" if false is returned.
+ * considered "safe for use" if true is returned.
*/
#define check_shl_overflow(a, s, d) __must_check_overflow(({ \
typeof(a) _a = a; \
--
2.25.4


2021-04-01 21:17:12

by Kees Cook

[permalink] [raw]
Subject: Re: [PATCH] overflow: improve check_shl_overflow comment

On Thu, 1 Apr 2021 09:06:29 -0700, Keith Busch wrote:
> A 'false' return means the value was safely set, so the comment should
> say 'true' for when it is not considered safe.

Oops, yes; too many inverse negatives. ;) Applied to for-next/overflow, thanks!

[1/1] overflow: Correct check_shl_overflow() comment
https://git.kernel.org/kees/c/4578be130a64

--
Kees Cook