From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 38B69F94CD9 for ; Wed, 22 Apr 2026 07:26:12 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4g0rPG5Lkgz2yZN; Wed, 22 Apr 2026 17:26:10 +1000 (AEST) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=172.105.4.254 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1776842770; cv=none; b=cUtM3kDUkYxMarvAHpyDfhombTGG6dyhr6G/1N+i3DsfvVsC6fOufyAd2ktPm4bwFWBW9RVeazO7w790fjl1E4321bhNvIIYcdBpxldU6o0XUNyLcRrEtCbvmPUo512UoCZhxCZseG9bR4E5GshE03LnLXJxTfCE3AvnjwX5jEGHwIx46iox8bmOXCNTYoTNemmH8b3vZsADZJ4X8QER8yCQ6kAEc6oQneg/QW4btoxKkpLPGa4+GAAOpmXBx7pkDhjk0sBk8jgdgeyQC+CKY8mtcoYOYptUw4oQPgyBIfNZs0T7nKjPg/ADO5w8wiyrc+TK4eWVgd1BgnsXiu18Mg== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1776842770; c=relaxed/relaxed; bh=7lK25W7+Mcjv1QQUKw5l94ZN7yEGQLyRTS4aEO3CXdU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=BJDH47VIVUefV91K3JbxMkKjJy8Z60kH/j3cSntqhdMK1T+sfXIjrRzkM+zziBxlylNWLoQoYD0uyBtRKf9NB02cxg17Reo8HouOk3IAFKTSwJ/tQDX6frLC2duiCXdm2hKOdnkOl1MkuckIw3GgV/f770GifpAwPeEJ1n8ODSFu+DuX5n+TE6UCDZPbCwRCZl+a0lq5LBlmMIAggKajvuoq6F3NB/St62/DIb+Y8H+AXqybyeZoQ/bteTS7NpoPGCTyZM1jDyH9Yz4ywpGb4Zz8aH7wlpjJ4WuhvRm5Kqm+xQfPTLKUdY4NpKOr7mhJPNMwWqbH0I7Xm83aLmN0EQ== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=EzBqLzuO; dkim-atps=neutral; spf=pass (client-ip=172.105.4.254; helo=tor.source.kernel.org; envelope-from=chleroy@kernel.org; receiver=lists.ozlabs.org) smtp.mailfrom=kernel.org Authentication-Results: lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=EzBqLzuO; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=172.105.4.254; helo=tor.source.kernel.org; envelope-from=chleroy@kernel.org; receiver=lists.ozlabs.org) Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4g0rPF401kz2xc8 for ; Wed, 22 Apr 2026 17:26:09 +1000 (AEST) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 87AF460018; Wed, 22 Apr 2026 07:26:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C7F7C19425; Wed, 22 Apr 2026 07:26:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776842765; bh=IvSjzT4GEYNAHFGcrljPx1kOL3wXhKmoqPv4Tv8CkaU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=EzBqLzuONJJv0ldtemEnj0bXdUh9Q6jzanPurHh8Miflfd8barSPM45kdHimemhIt 1eMFfC5fT848W+2iwSmKEnYavFqS3uq5Azd6rGxw0rP59V+eJy3bOVzvbsFXDS33WC mjJh2LRhXVMpQr97ZfguumkupzTHXoJ2J2RPpSWRVsxNZLt+L2c6OoxcMztVwNnh7X uiPZT0XNuZhd6gP48BoVOaHIojh6QR7HcqrMDL5pzMXXLYiJZsj4WVVj/qRUHgmtjn tNkCp+X4hCKUScXVf1gd3/4RrgzyMhcQvtV8NoXRLtRATX5ltBsI67PYcF1YVNifaV RymlAA9f3ksEQ== Message-ID: <5d16def3-3bad-49b1-866d-94a522e8d394@kernel.org> Date: Wed, 22 Apr 2026 09:26:02 +0200 X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: New warning in linus/master To: =?UTF-8?Q?Thomas_Wei=C3=9Fschuh?= , Ricardo Ribalda Cc: linux-arm-kernel@lists.infradead.org, Linux Kernel Mailing List , linuxppc-dev@lists.ozlabs.org References: <20260422071541-9a295128-d913-418f-a21c-1386fca30290@linutronix.de> Content-Language: fr-FR From: "Christophe Leroy (CS GROUP)" In-Reply-To: <20260422071541-9a295128-d913-418f-a21c-1386fca30290@linutronix.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Le 22/04/2026 à 07:56, Thomas Weißschuh a écrit : > Hi Ricardo, > > On Wed, Apr 22, 2026 at 11:51:45AM +0800, Ricardo Ribalda wrote: >> Media-CI has found a couple of new warnings in the latest kernel >> version for aarch64 and powerpc. They get fixed with this patch and >> before moving I wanted to know if this was under your radar. > > Thanks for the report. I was not aware of these so far. > >> diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile >> index 7dec05dd33b7..65914842fae0 100644 >> --- a/arch/arm64/kernel/vdso/Makefile >> +++ b/arch/arm64/kernel/vdso/Makefile >> @@ -50,7 +50,7 @@ CFLAGS_vgettimeofday.o = $(CC_FLAGS_ADD_VDSO) >> CFLAGS_vgetrandom.o = $(CC_FLAGS_ADD_VDSO) >> >> ifneq ($(c-gettimeofday-y),) >> - CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y) >> + CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y) >> -Wno-maybe-uninitialized >> endif > > (...) > > I'd like to know exactly what is going on before suppressing the warning. > It is a non-standard warning, only enabled by *some* of the vDSO builds > for some reason. > >> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitlab.freedesktop.org%2Flinux-media%2Fusers%2Fribalda%2F-%2Fpipelines%2F1649144%2Ftest_report%3Fjob_name%3Dcross-gcc&data=05%7C02%7Cchristophe.leroy2%40cs-soprasteria.com%7C5c0f15ee20a44072f47108dea0340304%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639124342424606113%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=9Tvp2aYfB02ijxVGLzCOYcMwZlPvqVDufxEporLl1mc%3D&reserved=0 > > While I was able to download a configuration from this job and also use the > same container image, I can not reproduce the issue. Is the configuration the > full one or only the template? > > Could you provide full reproduction steps? > >> CONFIG_CC_VERSION_TEXT="aarch64-linux-gnu-gcc (Debian 15.2.0-16) 15.2.0" > > The linked test log shows GCC 14.2, not 15.2. > Not that I could reproduce it with either one... > >> SYNC include/config/auto.conf >> CC arch/arm64/kernel/vdso/vgettimeofday.o >> In file included from : >> In function ‘vdso_set_timespec’, >> inlined from ‘do_aux’ at /workdir/lib/vdso/gettimeofday.c:266:2, >> inlined from ‘__cvdso_clock_gettime_common’ at >> /workdir/lib/vdso/gettimeofday.c:293:10, >> inlined from ‘__cvdso_clock_gettime_data.constprop’ at >> /workdir/lib/vdso/gettimeofday.c:306:7: >> /workdir/lib/vdso/gettimeofday.c:104:26: warning: ‘sec’ may be used >> uninitialized [-Wmaybe-uninitialized] >> 104 | ts->tv_sec = sec + __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns); >> | ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> /workdir/lib/vdso/gettimeofday.c: In function >> ‘__cvdso_clock_gettime_data.constprop’: >> /workdir/lib/vdso/gettimeofday.c:242:13: note: ‘sec’ was declared here >> 242 | u64 sec, ns; >> | ^~~ > > The same pattern is used in some other do_ handlers, which do not generate this > warning. I also can't immediately see what is wrong. You are likely in a special case where vdso_get_timestamp() returns false without setting &sec, and some versions of GCC and/or CLANG fail to see that vdso_set_timespec() is not called when vdso_get_timestamp() returns false. Christophe