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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 D678ACD4F54 for ; Thu, 28 May 2026 13:42:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5iz8ds4uZ2EdfTix40+LNtvuVP+Qe5SJurgkLudTtf8=; b=oj3q49LgxZfHckpQA1jRtwqo+a XMt+acciiPBbOnTWX31bFyUeWEZoLtu0lAVepnJ+4dvZ+QQNfYN9FIWoQmsKSzVTWl/X42G6wH6mT 4fGz+Wwsn3uEluVqR++w7yR3mgGAGMsexMTzn9nGMeBFjeq4wkNpvw8LRSQPqHqQ1g3H11foNyIUD w86bY+NsHrbn2qYYlbeMZPBWjy9FV9UerHIdq0dlcXnSF8iCD1zViPiqPwhnauAt+sA8Y2cmsqqx1 BMo/JO2KhZcSK6ivOoywALHJuyrSGjqomDqxbJGpSqdkUafKJKSA2Wc6Sws6j+jJHgQMuefSkUPCw ml8D2evA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wSb0U-00000005ndo-1him; Thu, 28 May 2026 13:42:42 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wSb0N-00000005nay-295R for linux-arm-kernel@lists.infradead.org; Thu, 28 May 2026 13:42:36 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 9B50C40E27; Thu, 28 May 2026 13:42:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 02F1B1F000E9; Thu, 28 May 2026 13:42:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779975754; bh=5iz8ds4uZ2EdfTix40+LNtvuVP+Qe5SJurgkLudTtf8=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=S/eOirRtRg+k9VxeW6cpoCGScVER7L0A1GqHjWMZGjObpzAi7rvaHZZBu9euEosWN elg3rKSSMkJFV7O5icFbkbAV6pYAglZGtL/5TphWk1AN0VdOKt9dBxJs5jXtU5RbAG TyOB7x92Fv4C3N6UKBJxYmCQhCCqBNJwd9YuvN6gGSED3+5/Bz5BpkLuiEZwi+mQAl 8xCRUKrQAbvujN/wzDQi0WtjiZxDnxJtGMixV9lW2FJ509ux3aJTvMx/a3p2L01sTj C9rrf7EHngjvrhtbTb0h+GvxlEk5o5SYNMF2HV019QRcpjTFvBGcV5F6LSR3Q12vtY lRbK4SVBt8nqQ== Date: Thu, 28 May 2026 14:42:28 +0100 From: Will Deacon To: Puranjay Mohan Cc: bpf@vger.kernel.org, Yonghong Song , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Kumar Kartikeya Dwivedi , Song Liu , Xu Kuohai , Catalin Marinas , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH bpf-next v2 1/3] bpf, arm64: Map BPF_REG_0 to x8 instead of x7 Message-ID: References: <20260427234801.2104511-1-puranjay@kernel.org> <20260427234801.2104511-2-puranjay@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260427234801.2104511-2-puranjay@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260528_064235_589414_EBA22EE0 X-CRM114-Status: GOOD ( 13.76 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Apr 27, 2026 at 04:47:58PM -0700, Puranjay Mohan wrote: > Move the BPF return value register from x7 to x8, freeing x7 for use > as an argument register. AAPCS64 designates x8 as the indirect result > location register; it is caller-saved and not used for argument > passing, making it a suitable home for BPF_REG_0. > > This is a prerequisite for stack argument support, which needs x5-x7 > to pass arguments 6-8 to native kfuncs following the AAPCS64 calling > convention. > > Signed-off-by: Yonghong Song > Signed-off-by: Puranjay Mohan > --- > arch/arm64/net/bpf_jit_comp.c | 4 ++-- > arch/arm64/net/bpf_timed_may_goto.S | 8 ++++---- > .../testing/selftests/bpf/progs/verifier_jit_inline.c | 2 +- > tools/testing/selftests/bpf/progs/verifier_ldsx.c | 6 +++--- > .../selftests/bpf/progs/verifier_private_stack.c | 10 +++++----- > 5 files changed, 15 insertions(+), 15 deletions(-) Makes sense to me: Acked-by: Will Deacon Will