From: Ian Rogers <irogers@google.com>
To: Yury Norov <yury.norov@gmail.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Arnd Bergmann <arnd@arndb.de>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <nick.desaulniers+lkml@gmail.com>,
Bill Wendling <morbo@google.com>,
Justin Stitt <justinstitt@google.com>,
Ian Rogers <irogers@google.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Jakub Kicinski <kuba@kernel.org>,
Jacob Keller <jacob.e.keller@intel.com>,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
llvm@lists.linux.dev
Subject: [PATCH v1 4/5] math64: Silence a clang -Wshorten-64-to-32 warning
Date: Thu, 3 Apr 2025 09:57:01 -0700 [thread overview]
Message-ID: <20250403165702.396388-5-irogers@google.com> (raw)
In-Reply-To: <20250403165702.396388-1-irogers@google.com>
The clang warning -Wshorten-64-to-32 can be useful to catch
inadvertent truncation. In some instances this truncation can lead to
changing the sign of a result, for example, truncation to return an
int to fit a sort routine. Silence the warning by making the implicit
truncation explicit.
Signed-off-by: Ian Rogers <irogers@google.com>
---
include/linux/math64.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/math64.h b/include/linux/math64.h
index 6aaccc1626ab..f32fcb2a2331 100644
--- a/include/linux/math64.h
+++ b/include/linux/math64.h
@@ -179,7 +179,7 @@ static __always_inline u64 mul_u64_u64_shr(u64 a, u64 mul, unsigned int shift)
#ifndef mul_u64_u32_shr
static __always_inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift)
{
- u32 ah = a >> 32, al = a;
+ u32 ah = a >> 32, al = (u32)a;
u64 ret;
ret = mul_u32_u32(al, mul) >> shift;
--
2.49.0.504.g3bcea36a83-goog
next prev parent reply other threads:[~2025-04-03 16:57 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-03 16:56 [PATCH v1 0/5] Silence some clang -Wshorten-64-to-32 warnings Ian Rogers
2025-04-03 16:56 ` [PATCH v1 1/5] bitfield: Silence a clang -Wshorten-64-to-32 warning Ian Rogers
2025-04-03 16:56 ` [PATCH v1 2/5] bitmap: " Ian Rogers
2025-04-04 5:49 ` Arnd Bergmann
2025-04-04 11:31 ` Ian Rogers
2025-04-03 16:57 ` [PATCH v1 3/5] bitops: " Ian Rogers
2025-04-04 5:43 ` Arnd Bergmann
2025-04-04 11:35 ` Ian Rogers
2025-04-03 16:57 ` Ian Rogers [this message]
2025-04-03 16:57 ` [PATCH v1 5/5] hash.h: " Ian Rogers
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=20250403165702.396388-5-irogers@google.com \
--to=irogers@google.com \
--cc=adrian.hunter@intel.com \
--cc=arnd@arndb.de \
--cc=jacob.e.keller@intel.com \
--cc=justinstitt@google.com \
--cc=kuba@kernel.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@rasmusvillemoes.dk \
--cc=llvm@lists.linux.dev \
--cc=morbo@google.com \
--cc=nathan@kernel.org \
--cc=nick.desaulniers+lkml@gmail.com \
--cc=tglx@linutronix.de \
--cc=yury.norov@gmail.com \
/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