From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 EAD842D23BC for ; Thu, 7 May 2026 16:51:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778172704; cv=none; b=sk5ToojZR5FzSCy7YYVvS4NTNdUiqKdY9Kcxd2R/KlmUpaXyinhUyCSfbCbLVCzwOmKpsbslJh5Y6dfwbEM5HUBsbtQJeazlYhaIsXAzBj8vt6KGrh1vLDdxd0DgjgEU0qePlOXC09PBW6/5pucROLArMSEdfC67jtzmoQ4oHRY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778172704; c=relaxed/simple; bh=dl6RaDm7Ip5oPijMV/k0nMQMwjFyQeZ/hdjoqfkmMPQ=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=K8wmGT5VI0+VF9Y2b4PslUc8i86UPc6EM8DcxoDeV+L2cobbR/7dc1SzedrxXGyANHBgpwny+d9K6Agjph5gRBPMl3yReDIlQVtilcSDJhC7XAvJnhF723UX/mSL75oi8iyHZOvNswoH5wQVNtoalV1cR6PnW8FVaZ+asZCcRuw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gzfd/zxB; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gzfd/zxB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E548BC2BCB2; Thu, 7 May 2026 16:51:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778172703; bh=dl6RaDm7Ip5oPijMV/k0nMQMwjFyQeZ/hdjoqfkmMPQ=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=gzfd/zxBaAH4jGP02/9Z5Bmw3ngrQXjbCwMRYbqmMQahkQAU5rgzkTMTDjbhcY8gD 04m2Da/wedqC6njRwfaDpnPJgH7073Tn3/ECWl8FV3lEM0nuzvYsVZlxLsl7EgOsMb KhYLhy6fHGvhCTSUwtV7Fe1EfNZHRXWu0fVtxvQ3X19cjrMYQe1IkMBngllH1W/eA1 LqaRcUsdq0ZnXJ2smEipn0rO+vxKhUVeeHQmnCH9uawBKfc5KbQg5T1dTLtCzpeQmo eIGntWQtz0JB4XWpZ1ZDPcp3jlkBe5tF3Mmc+ebVmbzQ5/CiLyxY9ixSKRDoQCXYr8 nxwH8Hi4gU89Q== From: Thomas Gleixner To: Thomas =?utf-8?Q?Wei=C3=9Fschuh?= Cc: LKML , Mathieu Desnoyers , =?utf-8?Q?Andr=C3=A8?= 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 Subject: Re: [patch V4 12/14] x86/vdso: Implement __vdso_futex_robust_try_unlock() In-Reply-To: <94b84f53-cf07-4f63-95bd-e4206f7c89b9@t-8ch.de> References: <20260402151131.876492985@kernel.org> <20260402151940.418303527@kernel.org> <878q9vwote.ffs@tglx> <94b84f53-cf07-4f63-95bd-e4206f7c89b9@t-8ch.de> Date: Thu, 07 May 2026 18:51:38 +0200 Message-ID: <875x4zw4bp.ffs@tglx> 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 Thu, May 07 2026 at 11:48, Thomas Wei=C3=9Fschuh wrote: > On 2026-05-07 11:29:01+0200, Thomas Gleixner wrote: >> On Wed, Apr 29 2026 at 10:44, Thomas Wei=C3=9Fschuh wrote: >> > On 2026-04-02 17:22:00+0200, Thomas Gleixner wrote: >> > (...) >> > >> >> + * When CONFIG_COMPAT is enabled then the 64-bit VDSO provides two f= unctions. >> >> + * One for the regular 64-bit sized pending operation pointer and on= e for a >> >> + * 32-bit sized pointer to support gaming emulators. >> > >> > These gaming emulators can emulate 32-bit code on 64-bit kernels even >> > without CONFIG_COMPAT. At least this is how I understand Wine WoW64 and >> > FEX-Emu. And in that case the 32-bit sized pointer function should be >> > available unconditionally, without the dependency on CONFIG_COMPAT. >>=20 >> That might well be, but that requires also the ability to register a >> 32-bit robust list for a 64-bit process, which is not supported right >> now. >>=20 >> So no, we are not exposing something half functional just because. That >> needs to be mopped up once we add the multi-robust list stuff. > > Fair enough. But this is also true for the 32-bit functions in the > x86_64 and x32 vDSOs when CONFIG_COMPAT=3Dy, no? When compat is enabled, then a 64-bit application can register a compat robust list via int80. Magic :)