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 1F6BF21A457; Sat, 15 Aug 2026 21:53:46 +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=1786830828; cv=none; b=SepZjrS/8CkjSp9j6fIoSNAkXURj35HZbkGoyD2qGGwZejgZfr0zelQAxYXZwkhkEMgRBAreqcy2VkzMc5DCir5caJs5avWrvOkTEIE4Ng3Ej4Fdhp25LYVq7onyVAM8Twi581EoH/XwE38trLR3/J2Id6eoDPL+4KYK6euaxp4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786830828; c=relaxed/simple; bh=TfaS4xsVEUti/Ld/sCXEUNN1G4AWkSUlF4uQG7INm0I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=RSsrbT3RyQe3Qn+ygCI6Bei4PwN4DvudPjEais8oc2NNQd/e9VGAcOBXmmDn9xGezdQknc9quoazah5UJPyA/Q8zlLmp8SzBoKUeqgoNNBzrk8k8wszr0Z7T33AU6PpLT3YZVr8LWBDG/k3sTokkkjx6gRG8gw85HPzuCnF5X4Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iYQysflY; 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="iYQysflY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 899231F000E9; Sat, 15 Aug 2026 21:53:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786830826; bh=L1xQp6TnnctvVRvsmBO7lNUazoq7APGQJNQv5Cgr9VY=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=iYQysflY5z6LJOT1PECEy9L7Pyjgx1OkM93zbDsKBNftTWEYrJM1TejoFe1QcGD1j vWUFEV3hP9K2B14HKBsAvHwR4JSu2Y/WoXijAtHIurutCR+a1kKKqOmPx9mfqgB943 UNSv9khD0ANzi2gjhOLAT/2GlKhoHuDyZbHoQKasx46rMvaHfp2dLKr+dP4vOm6tvK TyjVuSfM9PkRvDs1pDyiTNi24oR7kmZsPCx4kAAxiQauaLeWIxTA64PUj+rx43NIm3 NzK9CfqJnDii5NhMtSwvxLywVHYJMGUDfUE5KvY+51aHKRdnk/P7cR0mZLUg86BRut Mk8k4bt1Vgj5A== Received: by finisterre.sirena.org.uk (Postfix, from userid 1000) id 6EE2E1AC527F; Sat, 15 Aug 2026 22:53:43 +0100 (BST) Date: Sat, 15 Aug 2026 22:53:43 +0100 From: Mark Brown To: Josh Poimboeuf Cc: Catalin Marinas , Will Deacon , linux-kernel@vger.kernel.org, Ard Biesheuvel , linux-arm-kernel@lists.infradead.org, live-patching@vger.kernel.org, Song Liu , Miroslav Benes , Petr Mladek , Joe Lawrence , Mark Rutland , Nick Desaulniers , Kees Cook , Nathan Chancellor , linux-toolchains@vger.kernel.org Subject: Re: [PATCH 07/12] arm64/bti: Advertise BTI in assembly objects Message-ID: References: <5340f3df281bebc81aad3cd9a7471d95061b4b9d.1786768375.git.jpoimboe@kernel.org> Precedence: bulk X-Mailing-List: linux-toolchains@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="hHV2ZweC5h7oUr++" Content-Disposition: inline In-Reply-To: <5340f3df281bebc81aad3cd9a7471d95061b4b9d.1786768375.git.jpoimboe@kernel.org> X-Cookie: My vaseline is RUNNING... --hHV2ZweC5h7oUr++ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Aug 14, 2026 at 09:45:24PM -0700, Josh Poimboeuf wrote: > On a kernel whose text exceeds the +/-128MB direct branch range, the > linker inserts veneers. With BTI enabled, the veneers' indirect branch > targets need a BTI landing pad, which not all functions have starting > with Clang 21 (and for all versions of GCC). We already have explicit note generation support in asm/assembler.h which is used in the vDSO code, it probably makes sense to replace that too. I didn't check if there's potential for the two to collide with this as is. --hHV2ZweC5h7oUr++ Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmqA3+YACgkQJNaLcl1U h9A/DQf/WTnuS2TWA3jYmXlJx0LmO3Ydemf68Q8UJia96H0cXBoAVbvlCLGelBJ+ xwrW2pLUAszFkVhshCZn9wIsBxiaJHvjNEJBiV11UN27ogqwqkF8P5omVVAoUx9n Jd8YZb4KIDcof9ZXXeug2J5QFkXaZQ+TjCCAKunMT94QPA4Ku2PLSs41CVdm1aBB Hda9JTCPsvER87662JHG7mICgPmUmlDQKwHpxS9V9YE+/fx+kgARnoEGc1O32DOb JKhYD8v22nrMHu0sdcpQMwjc/6GDvB6nGzFsxtwqi9sOQ6RNDffXKaHWWnxY1+74 ZNAOYbZgbFNcnQb5BDrpiUMHGbWfjA== =y+lK -----END PGP SIGNATURE----- --hHV2ZweC5h7oUr++--