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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F0F3C43603 for ; Thu, 5 Dec 2019 12:54:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D46B2245C for ; Thu, 5 Dec 2019 12:54:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=dlink.ru header.i=@dlink.ru header.b="h0qVKVkg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729096AbfLEMyt (ORCPT ); Thu, 5 Dec 2019 07:54:49 -0500 Received: from fd.dlink.ru ([178.170.168.18]:35588 "EHLO fd.dlink.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729048AbfLEMys (ORCPT ); Thu, 5 Dec 2019 07:54:48 -0500 X-Greylist: delayed 552 seconds by postgrey-1.27 at vger.kernel.org; Thu, 05 Dec 2019 07:54:47 EST Received: by fd.dlink.ru (Postfix, from userid 5000) id BA9151B2120E; Thu, 5 Dec 2019 15:45:34 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 fd.dlink.ru BA9151B2120E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dlink.ru; s=mail; t=1575549934; bh=/HwG0dFNg/hWKid+bfXzTVGWal/DPp90hVFX4aHbrbc=; h=Date:From:To:Cc:Subject; b=h0qVKVkg/afttyYI0TPqWQxoWE7CX/0o+OlWKNMDa38VoiEfPQIwqQ9gEzuxu3AuI I+1TS9e8R/GXiVI+s2UXnwl76b7/Mugj7pyWAuMN3pdNxAtt2GEPvco0nwCjyd9T6v EEL3gg/GLINRC37K0Zf5KkF1sgD13+VgW4Zzf0Vs= Received: from mail.rzn.dlink.ru (mail.rzn.dlink.ru [178.170.168.13]) by fd.dlink.ru (Postfix) with ESMTP id 31A891B20153; Thu, 5 Dec 2019 15:45:28 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 fd.dlink.ru 31A891B20153 Received: from mail.rzn.dlink.ru (localhost [127.0.0.1]) by mail.rzn.dlink.ru (Postfix) with ESMTP id CB0771B217D8; Thu, 5 Dec 2019 15:45:27 +0300 (MSK) Received: from mail.rzn.dlink.ru (localhost [127.0.0.1]) by mail.rzn.dlink.ru (Postfix) with ESMTPA; Thu, 5 Dec 2019 15:45:27 +0300 (MSK) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Thu, 05 Dec 2019 15:45:27 +0300 From: Alexander Lobakin To: Paul Burton Cc: Hassan Naveed , Ralf Baechle , James Hogan , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Subject: MIPS eBPF JIT support on pre-32R2 User-Agent: Roundcube Webmail/1.4.0 Message-ID: <09d713a59665d745e21d021deeaebe0a@dlink.ru> X-Sender: alobakin@dlink.ru Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Hey all, I'm writing about lines arch/mips/net/ebpf_jit.c:1806-1807: if (!prog->jit_requested || MIPS_ISA_REV < 2) return prog; Do pre-32R2 architectures (32R1, maybe even R3000-like) actually support this eBPF JIT code? If they do, then the condition 'MIPS_ISA_REV < 2' should be removed as it is always true for them and tells CC to remove JIT completely. If they don't support instructions from this JIT, then the line arch/mips/Kconfig:50: select HAVE_EBPF_JIT if (!CPU_MICROMIPS) should be changed to something like: select HAVE_EBPF_JIT if !CPU_MICROMIPS && TARGET_ISA_REV >= 2 (and then the mentioned 'if' condition would become redundant) At the moment it is possible to build a kernel without both JIT and interpreter, but with CONFIG_BPF_SYSCALL=y (what should not be allowed I suppose?) within the following configuration: - select any pre-32R2 CPU (e.g. CONFIG_CPU_MIPS32_R1); - enable CONFIG_BPF_JIT (CONFIG_MIPS_EBPF_JIT will be autoselected); - enable CONFIG_BPF_JIT_ALWAYS_ON (this removes BPF interpreter from the system). I may prepare a proper patch by myself if needed (after clarification). Thanks. Regards, ᚷ ᛖ ᚢ ᚦ ᚠ ᚱ