From: Wake Liu <wakel@google.com>
To: Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: linux-kernel@vger.kernel.org, wakel@google.com
Subject: [PATCH] vdso: Define NSEC_PER_SEC as 64-bit to prevent overflow
Date: Wed, 6 Aug 2025 00:21:53 +0800 [thread overview]
Message-ID: <20250805162153.952693-1-wakel@google.com> (raw)
The constant NSEC_PER_SEC (1,000,000,000) is defined as a long literal.
On 32-bit systems like arm32, where long is 32 bits, this value can
overflow when used in 64-bit calculations.
This can lead to incorrect time calculations within the VDSO.
To fix this, define NSEC_PER_SEC as a long long literal (1000000000LL),
ensuring it is treated as a 64-bit value on all architectures and
preventing potential overflows.
Signed-off-by: Wake Liu <wakel@google.com>
---
include/vdso/time64.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/vdso/time64.h b/include/vdso/time64.h
index b40cfa2aa33c..07641b27d139 100644
--- a/include/vdso/time64.h
+++ b/include/vdso/time64.h
@@ -8,7 +8,7 @@
#define NSEC_PER_USEC 1000L
#define NSEC_PER_MSEC 1000000L
#define USEC_PER_SEC 1000000L
-#define NSEC_PER_SEC 1000000000L
+#define NSEC_PER_SEC 1000000000LL
#define PSEC_PER_SEC 1000000000000LL
#define FSEC_PER_SEC 1000000000000000LL
--
2.50.1.565.gc32cd1483b-goog
next reply other threads:[~2025-08-05 16:21 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-05 16:21 Wake Liu [this message]
2025-08-06 8:44 ` Thomas Gleixner
2025-08-06 8:55 ` Thomas Gleixner
2025-08-09 9:49 ` Wake Liu
2025-08-10 8:03 ` Thomas Gleixner
2025-08-10 8:28 ` Thomas Weißschuh
2025-09-15 19:19 ` [PATCH v2] selftests/timers: Consolidate and fix 32-bit overflow in timespec_sub Wake Liu
2025-09-21 7:49 ` Thomas Gleixner
2026-01-07 23:19 ` Carlos Llamas
2025-08-06 20:28 ` [PATCH] vdso: Define NSEC_PER_SEC as 64-bit to prevent overflow kernel test robot
2025-08-07 7:37 ` kernel test robot
-- strict thread matches above, loose matches on Subject: below --
2025-08-05 16:20 Wake Liu
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=20250805162153.952693-1-wakel@google.com \
--to=wakel@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=tglx@linutronix.de \
--cc=vincenzo.frascino@arm.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
all inboxes | Powered by JetHome®