From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 511D81F78E6 for ; Tue, 2 Jun 2026 20:02:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780430531; cv=none; b=Xe8oQliIpbynqAeb3qFzcwWqbo8QEd+g1stqIxCmh3XdiV8TsiV3vlVj37qvmzGmDf1eultvdc6v5vU9GijFknU/2UHdqajFZq7aEfYZiOCqCyKmEuSVRbGUZI26Iul2n4/PEF7yJLTyR6HtNYbK48CLimukpd2wVT/tII6QEZU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780430531; c=relaxed/simple; bh=HujNChxHHPDRNUeot7I6uJZ9yifFdI6qakbKOhwYSA8=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=idn6vV9ewhlL2dkYUpNKasDtNEg15mC7XJk0WrByUdn/yB0944Z04Xb+QktFnPqlmk8dBw9Vkhob4414oTL6g/0V+dy5IomM+NS0OPK0BaO6K1SADc+BX+Sl/FVSdAz6VcRAs2v4IsjfcLFHKtfoM0Jlpq/2p592MBsOs+QT+Ds= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DSDSLblA; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DSDSLblA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AE051F00893; Tue, 2 Jun 2026 20:02:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780430530; bh=aFOUTxo4yH9vZEjlM6BcH84AFD4gfQCu4vkY9Xr74yE=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=DSDSLblAzIWMmU5AIypCFHSrIZImpmNWKDrFzPTbsYSJwbysKbjO+4eYM/lxdQ3Yo lDiz7ypWou9fqsr2JhFrV5wM2uGPShMFHmY/xZ5nq1YaNWKMHhDQNV0zwee5QUQTcp pZlCJhUyuxVaky2ZB3ZS6yp2IARU23dHb1Yhm/tvSOYyI99IWR4CMU/Hx1ZtWe0bqc 3NlgQ4b448JrSavfcVMnWsLL2zINnqmoBgxzeNALAZSzsqmilACm8M9g/NCSa44lG0 c9Gt5Oa/tcuJfMCronUaCEkfyDx+lA27Oj1F/xZHf7FNDrAznCHXNSEg7jUYfKHY/T x13AsojprRsYg== From: Thomas Gleixner To: Thomas =?utf-8?Q?Wei=C3=9Fschuh?= Cc: LKML , Mathieu Desnoyers , =?utf-8?Q?Andr=C3=A9?= Almeida , Sebastian Andrzej Siewior , Carlos O'Donell , Peter Zijlstra , Florian Weimer , Rich Felker , Torvald Riegel , Darren Hart , Ingo Molnar , Davidlohr Bueso , Arnd Bergmann , "Liam R . Howlett" , Uros Bizjak , Mark Brown , Richard Weinberger Subject: Re: [patch V5 16/16] [RFC] vdso, x86: Expose vdso.so.dbg through sysfs In-Reply-To: <3d810e4e-1ae5-4b00-8c82-8b5d64c8adeb@t-8ch.de> References: <20260602084648.462672743@kernel.org> <20260602090536.045586688@kernel.org> <3d810e4e-1ae5-4b00-8c82-8b5d64c8adeb@t-8ch.de> Date: Tue, 02 Jun 2026 22:02:07 +0200 Message-ID: <87y0gw7lts.ffs@fw13> 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=utf-8 Content-Transfer-Encoding: quoted-printable On Tue, Jun 02 2026 at 12:39, Thomas Wei=C3=9Fschuh wrote: > On 2026-06-02 11:10:25+0200, Thomas Gleixner wrote: >> Finding the debug version of the VDSO is not trivial as there is no comm= on >> scheme where it is placed. That's especially problematic for CI testing. >>=20 >> The VDSO futex unlock mechanism requires for testing to have access to t= he >> inner labels of the unlock assembly, which are only accessible via the >> debug so. >>=20 >> Also for general debugging purposes it's conveniant to have access to the >> debug VDSO at a well defined place. >>=20 >> The files are placed in /sys/kernel/vdso/ and named vdso32.so.dbg, >> vdso64.so.dbg, vdsox32.so.dbg. > > How is a user supposed to find the correct one for a given task? > As currently proposed that requires architecture-specific logic. > > What about mirroring CONFIG_IKCONFIG and CONFIG_IKHEADERS, packaging > the output of 'make vdso_install' as an archive and embedding that > into the kernel. > > It has the following advantages: > * Can be loaded on-demand from a module. > * Does not require additional (per-architecture) code. > * Contains build-id symlinks which can be followed automatically to find > a task's debug vDSO. > > Currently CONFIG_IKHEADERS only provide the compressed archives, and not > a directly usable directory, though. That could be fine here, too. I'm fine with any sensible solution. This one just worked for my nefarious purposes and that's why it's marked RFC. :)