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=-3.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 13EF6C48BE2 for ; Thu, 20 Jun 2019 06:01:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D7D2720B1F for ; Thu, 20 Jun 2019 06:01:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="NcL5l3LL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726126AbfFTGBS (ORCPT ); Thu, 20 Jun 2019 02:01:18 -0400 Received: from mail-io1-f41.google.com ([209.85.166.41]:41040 "EHLO mail-io1-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725912AbfFTGBS (ORCPT ); Thu, 20 Jun 2019 02:01:18 -0400 Received: by mail-io1-f41.google.com with SMTP id w25so2423913ioc.8; Wed, 19 Jun 2019 23:01:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:message-id:in-reply-to:references:subject :mime-version:content-transfer-encoding; bh=MqzsYCHBzioG4bOrNkmWcUKVevjbBvwuF35diEvjshw=; b=NcL5l3LLLGw7PeJl+xcBFGqD4FfPr/xyhLw3NrW7XsmdZdl+P/bt80At4fPExKDJSh CK3+Yz1GaMoQCyGWKZXx/seQaIrSGKCOWog6tdmr70Yuqg8dUNUuJ9c3XizoFZ6+Kpae OHhb6FDTZy24LoiPgKxajPXB9VCHX7QRNO0tez7k+g+RF8gx+CHoP/ntT+ZQnQHW1ZFc ygZSA6ZZn6dRr3zB7SPMPx/Hr6gzCVsMXJjiqNnx70OzA+d/lQUWJXzUDCk60VFLsaRX HLE915TX2g14hQbs4lpXfz1LkQJzmZff3ggdMSuqy1El3OQMKJdbEtV8vPAuT1KbDE0r xgxQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:content-transfer-encoding; bh=MqzsYCHBzioG4bOrNkmWcUKVevjbBvwuF35diEvjshw=; b=Gm6kpOLHy6G42Nor+nwZs5d5uIthq1SBf8JL5KuXlNePWA3Wi1Na96wwqHbeObADat j1O9hn+mMQKHB/eO/E0w/xnikFkOZI7DQC7CjbGufL4kTsZLh3Xvc17DB630dB5FzvLA qpT5UJGXopBtMC/HIjDy8I5qTgzQmqt+2u6e5xy9K9RkP1G+rruAqqhM1BxxoksLELfq kXE5HyojZMoggHz9POpEVTuU63O8qAPYViFqnPcDQcRt01v6bmlkMWV7NNopTV0kony/ So83l8ra0tbJgp2LFpaBLAqkP6B8UH1nI3Yn9lfEtbPF4QFI7CAjIoUnLBbks+q1WMt/ C7KA== X-Gm-Message-State: APjAAAWaGA1ujx8Gj+0nx7qXqKiCjVov3GZ6hfpKRTb4FbHQNo5Fw43J nDPPmtl3wywWImW3HBgCoXs= X-Google-Smtp-Source: APXvYqzrxsYXF0GmUq/peRBzWINlXtlmZN2iPXhZY9Tc13TaIh7W1CxAz/J5C9QnkPrCvJ4gBxWKvg== X-Received: by 2002:a5e:9241:: with SMTP id z1mr30495408iop.39.1561010477447; Wed, 19 Jun 2019 23:01:17 -0700 (PDT) Received: from localhost ([184.63.162.180]) by smtp.gmail.com with ESMTPSA id t4sm15550991iop.0.2019.06.19.23.01.15 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Wed, 19 Jun 2019 23:01:16 -0700 (PDT) Date: Wed, 19 Jun 2019 23:01:10 -0700 From: John Fastabend To: Alexei Starovoitov , davem@davemloft.net Cc: daniel@iogearbox.net, netdev@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com Message-ID: <5d0b2126214c3_12352ac65c3c65c06a@john-XPS-13-9370.notmuch> In-Reply-To: <20190615191225.2409862-4-ast@kernel.org> References: <20190615191225.2409862-1-ast@kernel.org> <20190615191225.2409862-4-ast@kernel.org> Subject: RE: [PATCH v3 bpf-next 3/9] bpf: extend is_branch_taken to registers Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Alexei Starovoitov wrote: > This patch extends is_branch_taken() logic from JMP+K instructions > to JMP+X instructions. > Conditional branches are often done when src and dst registers > contain known scalars. In such case the verifier can follow > the branch that is going to be taken when program executes. > That speeds up the verification and is essential feature to support > bounded loops. > > Signed-off-by: Alexei Starovoitov > Acked-by: Andrii Nakryiko > --- Acked-by: John Fastabend