From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailout2.w1.samsung.com (mailout2.w1.samsung.com [210.118.77.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1DC352E0B6E for ; Tue, 8 Jul 2025 15:17:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=210.118.77.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751987845; cv=none; b=JAhs4vIsh348fzELWQtHVlxeQSLGZHHoYRDUY1y3YwOF1XYajkyUPf0CcWJ9yQBKYjp73Qy9bMF/Zmj1M/A9jug5ANKbTdcZGUTBmm5wF7gSdxROg8UtBynyAjxAelnpXmr5dplVfxwOgF/KmeXvUu12eiKYBjgSWdV6FmW1a0I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751987845; c=relaxed/simple; bh=AHNCCG5Tf5jpa/S+PhVW9zo376122RPdsJOEN6MRlrs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:From:In-Reply-To: Content-Type:References; b=sRpU2UEUBPVJ6fXGc5zHY6AzwrQCwsLnnybUGX0NMhJdqDfSUzr8PeXyHSO/JUxRGEmerYXZf4nEQTXOEP5HnUBgf3ez8qtdO5zix6Xlls3InVB60cVhP4jBSBKZIQk2kjWr9h2Cz5z6XXaK7zKNe2pxMJvtvm4GF0E3RXBk+do= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com; spf=pass smtp.mailfrom=samsung.com; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b=fXOqPdFw; arc=none smtp.client-ip=210.118.77.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=samsung.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b="fXOqPdFw" Received: from eucas1p2.samsung.com (unknown [182.198.249.207]) by mailout2.w1.samsung.com (KnoxPortal) with ESMTP id 20250708151721euoutp0232fc0fa626d8b0e357917322db4e7cb3~QT6jA_Uca0512205122euoutp02p for ; Tue, 8 Jul 2025 15:17:21 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout2.w1.samsung.com 20250708151721euoutp0232fc0fa626d8b0e357917322db4e7cb3~QT6jA_Uca0512205122euoutp02p DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1751987841; bh=yaTLIoaKytTb1Jem3YqYe98mw9JwFlUpJPDA2tKD898=; h=Date:Subject:To:Cc:From:In-Reply-To:References:From; b=fXOqPdFwqMbLXYSJm7Di2upblR2Tsgr1Trx7197+vRwt5Pdc5/zRWXqN0QRFhZrun VVH57VAHLUm2Ytt/wpez3Y3vhPkBUg8FXf747xPsIhpvJeTwq6445TrELjgQG/ogZk 1OB8tRI2SDQnT/n7bc0/lyyjF8FkWzyWYo+KguIs= Received: from eusmtip2.samsung.com (unknown [203.254.199.222]) by eucas1p2.samsung.com (KnoxPortal) with ESMTPA id 20250708151720eucas1p260f984fd95d3460d3e9f6c9b48e0e25c~QT6iepPcr1882718827eucas1p2A; Tue, 8 Jul 2025 15:17:20 +0000 (GMT) Received: from [106.210.134.192] (unknown [106.210.134.192]) by eusmtip2.samsung.com (KnoxPortal) with ESMTPA id 20250708151718eusmtip2dcd49f64a9e9889791acd662135310b6~QT6gkeBFF2780927809eusmtip22; Tue, 8 Jul 2025 15:17:18 +0000 (GMT) Message-ID: <02bcd954-5323-4663-a766-f53c67c5a18f@samsung.com> Date: Tue, 8 Jul 2025 17:17:18 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 06/14] vdso/gettimeofday: Return bool from clock_gettime() helpers To: =?UTF-8?Q?Thomas_Wei=C3=9Fschuh?= , Andy Lutomirski , Thomas Gleixner , Vincenzo Frascino , Shuah Khan , Anna-Maria Behnsen , Frederic Weisbecker , John Stultz , Stephen Boyd , Catalin Marinas , Will Deacon , Arnd Bergmann Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, Richard Cochran , Christopher Hall , Miroslav Lichvar , Werner Abt , David Woodhouse , Kurt Kanzenbach , Nam Cao , Antoine Tenart Content-Language: en-US From: Marek Szyprowski In-Reply-To: <20250701-vdso-auxclock-v1-6-df7d9f87b9b8@linutronix.de> Content-Transfer-Encoding: 8bit X-CMS-MailID: 20250708151720eucas1p260f984fd95d3460d3e9f6c9b48e0e25c X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" X-RootMTR: 20250708151720eucas1p260f984fd95d3460d3e9f6c9b48e0e25c X-EPHeader: CA X-CMS-RootMailID: 20250708151720eucas1p260f984fd95d3460d3e9f6c9b48e0e25c References: <20250701-vdso-auxclock-v1-0-df7d9f87b9b8@linutronix.de> <20250701-vdso-auxclock-v1-6-df7d9f87b9b8@linutronix.de> On 01.07.2025 10:58, Thomas Weißschuh wrote: > The internal helpers are effectively using boolean results, > while pretending to use error numbers. > > Switch the return type to bool for more clarity. > > Signed-off-by: Thomas Weißschuh > --- > lib/vdso/gettimeofday.c | 58 +++++++++++++++++++++++++------------------------ > 1 file changed, 30 insertions(+), 28 deletions(-) This patch landed in today's linux-next as commit fcc8e46f768f ("vdso/gettimeofday: Return bool from clock_gettime() helpers"). In my tests I found that it causes serious problem with hwclock operation on some of my ARM 32bit test boards. I observe that calling "hwclock -w -f /dev/rtc0" never ends on those boards. Disabling vdso support (by removing ARM architected timer) fixes this issue. > diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c > index 9b77f23566f6a35887d4c9aaefc61a971131b499..c5266532a097c06f33d12e345c695357d75abf42 100644 > --- a/lib/vdso/gettimeofday.c > +++ b/lib/vdso/gettimeofday.c > @@ -82,8 +82,8 @@ const struct vdso_time_data *__arch_get_vdso_u_timens_data(const struct vdso_tim > #endif /* CONFIG_GENERIC_VDSO_DATA_STORE */ > > static __always_inline > -int do_hres_timens(const struct vdso_time_data *vdns, const struct vdso_clock *vcns, > - clockid_t clk, struct __kernel_timespec *ts) > +bool do_hres_timens(const struct vdso_time_data *vdns, const struct vdso_clock *vcns, > + clockid_t clk, struct __kernel_timespec *ts) > { > const struct vdso_time_data *vd = __arch_get_vdso_u_timens_data(vdns); > const struct timens_offset *offs = &vcns->offset[clk]; > @@ -103,11 +103,11 @@ int do_hres_timens(const struct vdso_time_data *vdns, const struct vdso_clock *v > seq = vdso_read_begin(vc); > > if (unlikely(!vdso_clocksource_ok(vc))) > - return -1; > + return false; > > cycles = __arch_get_hw_counter(vc->clock_mode, vd); > if (unlikely(!vdso_cycles_ok(cycles))) > - return -1; > + return false; > ns = vdso_calc_ns(vc, cycles, vdso_ts->nsec); > sec = vdso_ts->sec; > } while (unlikely(vdso_read_retry(vc, seq))); > @@ -123,7 +123,7 @@ int do_hres_timens(const struct vdso_time_data *vdns, const struct vdso_clock *v > ts->tv_sec = sec + __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns); > ts->tv_nsec = ns; > > - return 0; > + return true; > } > #else > static __always_inline > @@ -133,16 +133,16 @@ const struct vdso_time_data *__arch_get_vdso_u_timens_data(const struct vdso_tim > } > > static __always_inline > -int do_hres_timens(const struct vdso_time_data *vdns, const struct vdso_clock *vcns, > - clockid_t clk, struct __kernel_timespec *ts) > +bool do_hres_timens(const struct vdso_time_data *vdns, const struct vdso_clock *vcns, > + clockid_t clk, struct __kernel_timespec *ts) > { > - return -EINVAL; > + return false; > } > #endif > > static __always_inline > -int do_hres(const struct vdso_time_data *vd, const struct vdso_clock *vc, > - clockid_t clk, struct __kernel_timespec *ts) > +bool do_hres(const struct vdso_time_data *vd, const struct vdso_clock *vc, > + clockid_t clk, struct __kernel_timespec *ts) > { > const struct vdso_timestamp *vdso_ts = &vc->basetime[clk]; > u64 cycles, sec, ns; > @@ -150,7 +150,7 @@ int do_hres(const struct vdso_time_data *vd, const struct vdso_clock *vc, > > /* Allows to compile the high resolution parts out */ > if (!__arch_vdso_hres_capable()) > - return -1; > + return false; > > do { > /* > @@ -173,11 +173,11 @@ int do_hres(const struct vdso_time_data *vd, const struct vdso_clock *vc, > smp_rmb(); > > if (unlikely(!vdso_clocksource_ok(vc))) > - return -1; > + return false; > > cycles = __arch_get_hw_counter(vc->clock_mode, vd); > if (unlikely(!vdso_cycles_ok(cycles))) > - return -1; > + return false; > ns = vdso_calc_ns(vc, cycles, vdso_ts->nsec); > sec = vdso_ts->sec; > } while (unlikely(vdso_read_retry(vc, seq))); > @@ -189,13 +189,13 @@ int do_hres(const struct vdso_time_data *vd, const struct vdso_clock *vc, > ts->tv_sec = sec + __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns); > ts->tv_nsec = ns; > > - return 0; > + return true; > } > > #ifdef CONFIG_TIME_NS > static __always_inline > -int do_coarse_timens(const struct vdso_time_data *vdns, const struct vdso_clock *vcns, > - clockid_t clk, struct __kernel_timespec *ts) > +bool do_coarse_timens(const struct vdso_time_data *vdns, const struct vdso_clock *vcns, > + clockid_t clk, struct __kernel_timespec *ts) > { > const struct vdso_time_data *vd = __arch_get_vdso_u_timens_data(vdns); > const struct timens_offset *offs = &vcns->offset[clk]; > @@ -223,20 +223,20 @@ int do_coarse_timens(const struct vdso_time_data *vdns, const struct vdso_clock > */ > ts->tv_sec = sec + __iter_div_u64_rem(nsec, NSEC_PER_SEC, &nsec); > ts->tv_nsec = nsec; > - return 0; > + return true; > } > #else > static __always_inline > -int do_coarse_timens(const struct vdso_time_data *vdns, const struct vdso_clock *vcns, > - clockid_t clk, struct __kernel_timespec *ts) > +bool do_coarse_timens(const struct vdso_time_data *vdns, const struct vdso_clock *vcns, > + clockid_t clk, struct __kernel_timespec *ts) > { > - return -1; > + return false; > } > #endif > > static __always_inline > -int do_coarse(const struct vdso_time_data *vd, const struct vdso_clock *vc, > - clockid_t clk, struct __kernel_timespec *ts) > +bool do_coarse(const struct vdso_time_data *vd, const struct vdso_clock *vc, > + clockid_t clk, struct __kernel_timespec *ts) > { > const struct vdso_timestamp *vdso_ts = &vc->basetime[clk]; > u32 seq; > @@ -258,10 +258,10 @@ int do_coarse(const struct vdso_time_data *vd, const struct vdso_clock *vc, > ts->tv_nsec = vdso_ts->nsec; > } while (unlikely(vdso_read_retry(vc, seq))); > > - return 0; > + return true; > } > > -static __always_inline int > +static __always_inline bool > __cvdso_clock_gettime_common(const struct vdso_time_data *vd, clockid_t clock, > struct __kernel_timespec *ts) > { > @@ -270,7 +270,7 @@ __cvdso_clock_gettime_common(const struct vdso_time_data *vd, clockid_t clock, > > /* Check for negative values or invalid clocks */ > if (unlikely((u32) clock >= MAX_CLOCKS)) > - return -1; > + return false; > > /* > * Convert the clockid to a bitmask and use it to check which > @@ -284,7 +284,7 @@ __cvdso_clock_gettime_common(const struct vdso_time_data *vd, clockid_t clock, > else if (msk & VDSO_RAW) > vc = &vc[CS_RAW]; > else > - return -1; > + return false; > > return do_hres(vd, vc, clock, ts); > } > @@ -293,9 +293,11 @@ static __maybe_unused int > __cvdso_clock_gettime_data(const struct vdso_time_data *vd, clockid_t clock, > struct __kernel_timespec *ts) > { > - int ret = __cvdso_clock_gettime_common(vd, clock, ts); > + bool ok; > > - if (unlikely(ret)) > + ok = __cvdso_clock_gettime_common(vd, clock, ts); > + > + if (unlikely(!ok)) > return clock_gettime_fallback(clock, ts); > return 0; > } > Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland