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From: "Thomas Weißschuh" <linux@weissschuh.net>
To: Willy Tarreau <w@1wt.eu>, Shuah Khan <shuah@kernel.org>
Cc: "Arnd Bergmann" <arnd@arndb.de>,
	linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
	"Thomas Weißschuh" <linux@weissschuh.net>
Subject: [PATCH 08/12] tools/nolibc: gettimeofday(): avoid libgcc 64-bit divisions
Date: Wed, 29 Oct 2025 17:02:58 +0100	[thread overview]
Message-ID: <20251029-nolibc-uapi-types-v1-8-e79de3b215d8@weissschuh.net> (raw)
In-Reply-To: <20251029-nolibc-uapi-types-v1-0-e79de3b215d8@weissschuh.net>

timespec::tv_nsec is going to be 64-bit wide even on 32-bit
architectures. As not all architectures support 64-bit division
instructions, calls to libgcc (__divdi3()) may be emitted by the
compiler which are not provided by nolibc.

As tv_nsec is guaranteed to always fit into an uint32_t, perform a
32-bit division instead.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/include/nolibc/sys/time.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/include/nolibc/sys/time.h b/tools/include/nolibc/sys/time.h
index 33782a19aae9..6dd3705c6c9d 100644
--- a/tools/include/nolibc/sys/time.h
+++ b/tools/include/nolibc/sys/time.h
@@ -33,7 +33,7 @@ int sys_gettimeofday(struct timeval *tv, struct timezone *tz)
 	ret = sys_clock_gettime(CLOCK_REALTIME, &tp);
 	if (!ret && tv) {
 		tv->tv_sec = tp.tv_sec;
-		tv->tv_usec = tp.tv_nsec / 1000;
+		tv->tv_usec = (uint32_t)tp.tv_nsec / 1000;
 	}
 
 	return ret;

-- 
2.51.1.dirty


  parent reply	other threads:[~2025-10-29 16:04 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-29 16:02 [PATCH 00/12] tools/nolibc: always use 64-bit ino_t, off_t and time-related types Thomas Weißschuh
2025-10-29 16:02 ` [PATCH 01/12] tools/nolibc: use 64-bit ino_t Thomas Weißschuh
2025-10-29 16:02 ` [PATCH 02/12] tools/nolibc: handle 64-bit off_t for llseek Thomas Weißschuh
2025-10-30 14:56   ` Arnd Bergmann
2025-10-29 16:02 ` [PATCH 03/12] tools/nolibc: prefer the llseek syscall Thomas Weißschuh
2025-10-29 16:02 ` [PATCH 04/12] tools/nolibc: use 64-bit off_t Thomas Weißschuh
2025-10-29 16:02 ` [PATCH 05/12] tools/nolibc: remove now superfluous overflow check in llseek Thomas Weißschuh
2025-10-30 14:58   ` Arnd Bergmann
2025-10-29 16:02 ` [PATCH 06/12] tools/nolibc: remove more __nolibc_enosys() fallbacks Thomas Weißschuh
2025-10-29 16:02 ` [PATCH 07/12] tools/nolibc: prefer explicit 64-bit time-related system calls Thomas Weißschuh
2025-10-30 14:44   ` Arnd Bergmann
2025-10-29 16:02 ` Thomas Weißschuh [this message]
2025-10-30 14:57   ` [PATCH 08/12] tools/nolibc: gettimeofday(): avoid libgcc 64-bit divisions Arnd Bergmann
2025-11-02  8:31   ` Willy Tarreau
2025-11-02  9:27     ` Thomas Weißschuh
2025-11-02  9:49       ` Willy Tarreau
2025-10-29 16:02 ` [PATCH 09/12] tools/nolibc: use a custom struct timespec Thomas Weißschuh
2025-10-30 14:46   ` Arnd Bergmann
2025-11-02  8:36     ` Willy Tarreau
2025-11-02  8:40       ` Willy Tarreau
2025-11-02  9:41       ` Thomas Weißschuh
2025-11-02  9:50         ` Willy Tarreau
2025-10-29 16:03 ` [PATCH 10/12] tools/nolibc: always use 64-bit time types Thomas Weißschuh
2025-10-29 16:03 ` [PATCH 11/12] selftests/nolibc: test compatibility of timespec and __kernel_timespec Thomas Weißschuh
2025-10-29 16:03 ` [PATCH 12/12] tools/nolibc: remove time conversions Thomas Weißschuh
2025-10-30 14:58   ` Arnd Bergmann
2025-11-02  8:44 ` [PATCH 00/12] tools/nolibc: always use 64-bit ino_t, off_t and time-related types Willy Tarreau

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