From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from todd.t-8ch.de (todd.t-8ch.de [159.69.126.157]) (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 6B2B41EB9EF; Sun, 2 Mar 2025 22:03:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.69.126.157 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740952995; cv=none; b=lZgKHX/ya3k37211I62rWC4A16gm+3DDQJCbymi3F8jqtNYWvFFAG8hHzxEEaWnudyRexKq8vApGOtnNpqCtuoZC4Dej0UW21eFR55YIr1ay0t/2gzJmIWEmHJnmThP8kginKsxqpqkEBpAUwevefObvd0Q0NAty/doyy8zODHo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740952995; c=relaxed/simple; bh=X3Oi7SmifOfnACnk6HXp/r98e88xQlGHmGmpB5IQCA8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FfFskYWA7ys1jn6v508NV1TDEVLqWm5Z4gW2UeeQYzK7djSM++he8QTt9/uboERkNiCGR4V7llk8Ux7xchfVZdtAqUdYqxxc0A21wzg7kvsF4hkNjljizvLpfACSI0hzhFI9qllSzIA/0JnMPgjvOXTd9oiutxA6AaXZTW90WMk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=weissschuh.net; spf=pass smtp.mailfrom=weissschuh.net; dkim=pass (1024-bit key) header.d=weissschuh.net header.i=@weissschuh.net header.b=kL2MSUia; arc=none smtp.client-ip=159.69.126.157 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=weissschuh.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=weissschuh.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=weissschuh.net header.i=@weissschuh.net header.b="kL2MSUia" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=weissschuh.net; s=mail; t=1740952561; bh=X3Oi7SmifOfnACnk6HXp/r98e88xQlGHmGmpB5IQCA8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kL2MSUiaL7zWpljLHyDr5g51GmjgO8dtCUftGCBzQ7uoq3DWHCC1/WgMpzfj2T6Qe TW6UqcO3fpULW9yoavs2cVzpSboP9ZSkX9SSDKLNi64g9kl2fNJjt5eA/m3gwi/5fd vNxJGU89eQDSq6Chl9EDOac9bGUNKP9IE5rOK0Zg= Date: Sun, 2 Mar 2025 22:56:01 +0100 From: Thomas =?utf-8?Q?Wei=C3=9Fschuh?= To: Willy Tarreau Cc: Shuah Khan , linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] selftests/nolibc: only run constructor tests on nolibc Message-ID: <8dde4be5-0b37-4e45-bea3-8cdadeb23e7a@t-8ch.de> References: <20250212-nolibc-test-constructor-v1-1-c963875b3da4@weissschuh.net> <20250216093940.GA2192@1wt.eu> <670b08a4-9bc5-4700-94bb-272fda5c59d7@t-8ch.de> <20250222093851.GA13258@1wt.eu> <20250301110735.GA18621@1wt.eu> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250301110735.GA18621@1wt.eu> Hi Willy! On 2025-03-01 12:07:35+0100, Willy Tarreau wrote: > [..] > OK so I've tested the patch below which does what we want, except that > it reveals that the order is still not granted. Actually I haven't found > what dictates it. On one machine (gcc-9.5, ld-2.26) I'm getting: > > $ ./nolibc-test|grep cst > 17 linkage_cst = 0 [FAIL] > 18 linkage_cst_ord = 0 [FAIL] Apparently no constructors are executed at all. Can you show the default linkerscript used? gcc -static -o /dev/null /dev/null -Wl,--verbose > On this same machine, using another toolchain relying on ld-2.27 gives me > this: > > $ ./nolibc-test|grep cst > 17 linkage_cst = 1 [OK] > 18 linkage_cst_ord = 33 [FAIL] > > And I'm getting this as well on another machine with various toolchains > such as gcc-9.5+ld-2.34. The nolibc toolchains fail similarly on gcc-5.5 > (ld-2.27) and gcc-6.5 (ld-2.32), but work for gcc-7.5 with ld-2.32, while > other combinations do work: > > $ ./nolibc-test|grep -i cst > 17 linkage_cst = 1 [OK] > 18 linkage_cst_ord = 18 [OK] > > All of this is a bit confusing. > > I continue not to understand what could guarantee an implicit execution > order since for me it solely depends on how things are linked, so the > purpose of the test remains uncertain to me and I think we'd rather not > try to enforce any ordering that might work only by pure luck. I don't think anything guarantees the order. It is just what happened to work in my tests so far. > What do you think ? Let's get rid of the validation. Thomas