From: Vincent Mailhol <mailhol@kernel.org>
To: Nathan Chancellor <nathan@kernel.org>,
Nicolas Schier <nsc@kernel.org>,
Nick Desaulniers <nick.desaulniers+lkml@gmail.com>,
Bill Wendling <morbo@google.com>,
Justin Stitt <justinstitt@google.com>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
David Airlie <airlied@gmail.com>,
Simona Vetter <simona@ffwll.ch>, Chris Mason <clm@fb.com>,
David Sterba <dsterba@suse.com>, Kees Cook <kees@kernel.org>,
"Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
linux-kbuild@vger.kernel.org, linux-sparse@vger.kernel.org,
linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
dri-devel@lists.freedesktop.org, linux-btrfs@vger.kernel.org,
linux-hardening@vger.kernel.org,
Vincent Mailhol <mailhol@kernel.org>
Subject: [PATCH v3 3/3] overflow: Remove is_non_negative() and is_negative()
Date: Sat, 20 Dec 2025 12:02:21 +0100 [thread overview]
Message-ID: <20251220-remove_wtype-limits-v3-3-24b170af700e@kernel.org> (raw)
In-Reply-To: <20251220-remove_wtype-limits-v3-0-24b170af700e@kernel.org>
The is_non_negative() and is_negative() function-like macros just
exist as a workaround to silence the -Wtype-limits warning. Now that
this warning is disabled, those two macros have lost their raison
d'être. Remove them.
This reverts commit dc7fe518b049 ("overflow: Fix -Wtype-limits
compilation warnings").
Suggested-by: Nicolas Schier <nsc@kernel.org>
Link: https://lore.kernel.org/all/aUT_yWin_xslnOFh@derry.ads.avm.de
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
Changelog:
v1 -> v2: new patch
---
include/linux/overflow.h | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/include/linux/overflow.h b/include/linux/overflow.h
index 736f633b2d5f..ab142d60c6b5 100644
--- a/include/linux/overflow.h
+++ b/include/linux/overflow.h
@@ -36,12 +36,6 @@
#define __type_min(T) ((T)((T)-type_max(T)-(T)1))
#define type_min(t) __type_min(typeof(t))
-/*
- * Avoids triggering -Wtype-limits compilation warning,
- * while using unsigned data types to check a < 0.
- */
-#define is_non_negative(a) ((a) > 0 || (a) == 0)
-#define is_negative(a) (!(is_non_negative(a)))
/*
* Allows for effectively applying __must_check to a macro so we can have
@@ -201,9 +195,9 @@ static inline bool __must_check __must_check_overflow(bool overflow)
typeof(d) _d = d; \
unsigned long long _a_full = _a; \
unsigned int _to_shift = \
- is_non_negative(_s) && _s < 8 * sizeof(*d) ? _s : 0; \
+ _s >= 0 && _s < 8 * sizeof(*d) ? _s : 0; \
*_d = (_a_full << _to_shift); \
- (_to_shift != _s || is_negative(*_d) || is_negative(_a) || \
+ (_to_shift != _s || *_d < 0 || _a < 0 || \
(*_d >> _to_shift) != _a); \
}))
--
2.51.2
next prev parent reply other threads:[~2025-12-20 11:03 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-20 11:02 [PATCH v3 0/3] kbuild: remove gcc's -Wtype-limits Vincent Mailhol
2025-12-20 11:02 ` [PATCH v3 1/3] " Vincent Mailhol
2025-12-20 11:02 ` [PATCH v3 2/3] kbuild: cleanup local -Wno-type-limits exceptions Vincent Mailhol
2025-12-20 12:53 ` Nicolas Schier
2025-12-20 11:02 ` Vincent Mailhol [this message]
2025-12-20 12:52 ` [PATCH v3 3/3] overflow: Remove is_non_negative() and is_negative() Nicolas Schier
2025-12-22 10:03 ` kernel test robot
2025-12-22 18:39 ` Vincent Mailhol
2025-12-22 19:55 ` kernel test robot
2025-12-25 6:04 ` kernel test robot
2025-12-27 8:49 ` kernel test robot
2025-12-28 1:41 ` kernel test robot
2026-01-01 15:10 ` Vincent Mailhol
2026-01-01 19:39 ` Nicolas Schier
2026-01-02 11:04 ` Miguel Ojeda
2026-01-02 22:26 ` Vincent Mailhol
2026-01-02 22:29 ` [PATCH] overflow: Update is_non_negative() and is_negative() comment Vincent Mailhol
2026-01-03 10:02 ` Dan Carpenter
2026-01-03 11:10 ` Vincent Mailhol
2026-01-03 16:56 ` Dan Carpenter
2026-01-03 19:40 ` Vincent Mailhol
2026-01-05 7:26 ` Dan Carpenter
2026-01-05 23:56 ` [PATCH v3 0/3] kbuild: remove gcc's -Wtype-limits Nathan Chancellor
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20251220-remove_wtype-limits-v3-3-24b170af700e@kernel.org \
--to=mailhol@kernel.org \
--cc=airlied@gmail.com \
--cc=clm@fb.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=dsterba@suse.com \
--cc=gustavoars@kernel.org \
--cc=justinstitt@google.com \
--cc=kees@kernel.org \
--cc=linux-btrfs@vger.kernel.org \
--cc=linux-hardening@vger.kernel.org \
--cc=linux-kbuild@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sparse@vger.kernel.org \
--cc=llvm@lists.linux.dev \
--cc=maarten.lankhorst@linux.intel.com \
--cc=morbo@google.com \
--cc=mripard@kernel.org \
--cc=nathan@kernel.org \
--cc=nick.desaulniers+lkml@gmail.com \
--cc=nsc@kernel.org \
--cc=simona@ffwll.ch \
--cc=torvalds@linux-foundation.org \
--cc=tzimmermann@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).