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=-1.0 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 66DFFC282E0 for ; Fri, 19 Apr 2019 21:33:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 311AF21736 for ; Fri, 19 Apr 2019 21:33:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=netronome-com.20150623.gappssmtp.com header.i=@netronome-com.20150623.gappssmtp.com header.b="DdepZrJp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727709AbfDSVdQ (ORCPT ); Fri, 19 Apr 2019 17:33:16 -0400 Received: from mail-qt1-f196.google.com ([209.85.160.196]:34943 "EHLO mail-qt1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727691AbfDSVdP (ORCPT ); Fri, 19 Apr 2019 17:33:15 -0400 Received: by mail-qt1-f196.google.com with SMTP id h39so6697593qte.2 for ; Fri, 19 Apr 2019 14:33:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :organization:mime-version:content-transfer-encoding; bh=ZpQBvk7zCNUFbvz2C+GE7Q0Mns/KASImiLm7Gow9pps=; b=DdepZrJpfPvyPfKdOKa2vGSmqcIIS/2U7nQC7r150wf6w7p0xaYqIRQH7ix9Xz+KHo wyXgARKb79bD7uQrj9Sw5AeKUAgmYoN43CnYmINd0v8nLTzux925StP5AAdb2LBkoJ9+ fjuAvmOvSSYKM2lQtUNFl4Xkgv0QLWEle7BMz/9LlKoHTYy8e7Bo9A3EO5JrZM59A9GT /VKIdyydtjPZjFOK8TLi0PQvhivVp9Za8x92g18X5uC90uMixHOwYzXgVzH25zSYbHlM fQxetJ3WYSNs5R5iQ6pSxtd5BWuQ/5jahRq/cSGzfke8rGLGg5uv5A0WMEi3G5yj+Ooz 5Gsw== 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:subject:message-id:in-reply-to :references:organization:mime-version:content-transfer-encoding; bh=ZpQBvk7zCNUFbvz2C+GE7Q0Mns/KASImiLm7Gow9pps=; b=gm2d1DU6zBziiWkoT0IJRpTi61KJHmycAoUzSj8x40FzohWVHQbZqqBZXa779jG8Jo FRu7XxKSA87Y5Fj8U6AulHAZu1yL6vFKYcqhf5OYbkcMhXU1dXawnLbhmBEhnzsduJxz EJxm8a49YFZv0230HhAK3jERMlDeY4SMWgvergmMpcX5YBIGRfhTlKdrVlmud6KAkPeu p2R5xzYNVv1+g9TfmOawzxpAdtV2dTeVuXj6qbVyR+29u7J/U7PJMT0BKqHmBzBQRZuS qlCcXXb7NxDfrCE5hmrkOYZYYdULb1V+wVQV7Axs2gmnNXKwPapNZg5OaOfhM+f4SDKx GAPg== X-Gm-Message-State: APjAAAUPSWTpUYsBUIpxl2cpeqet+OObNg2XDheHcuhyQFFXhZrPTnF9 TSUYdFmwX6RZ32CZlgYGngRyymQal7A= X-Google-Smtp-Source: APXvYqyEFKHwim6CfT6O8iP/RmjEjdj0bjbM8IV0oHS8V3KgWWY0mvJqih5pe+cJ4PD1Z3DYtU2oBA== X-Received: by 2002:a0c:afb0:: with SMTP id s45mr5076253qvc.151.1555709594817; Fri, 19 Apr 2019 14:33:14 -0700 (PDT) Received: from cakuba.netronome.com ([66.60.152.14]) by smtp.gmail.com with ESMTPSA id e128sm3159780qkd.79.2019.04.19.14.33.13 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 19 Apr 2019 14:33:14 -0700 (PDT) Date: Fri, 19 Apr 2019 14:33:10 -0700 From: Jakub Kicinski To: Alexei Starovoitov Cc: Jiong Wang , daniel@iogearbox.net, bpf@vger.kernel.org, netdev@vger.kernel.org, oss-drivers@netronome.com Subject: Re: [PATCH v4 bpf-next 02/15] bpf: mark lo32 writes that should be zero extended into hi32 Message-ID: <20190419143310.6c749160@cakuba.netronome.com> In-Reply-To: <20190419211403.6iovh26bu6cg2x36@ast-mbp.dhcp.thefacebook.com> References: <1555349185-12508-1-git-send-email-jiong.wang@netronome.com> <1555349185-12508-3-git-send-email-jiong.wang@netronome.com> <20190418235747.jv4yocuf6fgwahli@ast-mbp.dhcp.thefacebook.com> <20190419134051.71eeea08@cakuba.netronome.com> <20190419211403.6iovh26bu6cg2x36@ast-mbp.dhcp.thefacebook.com> Organization: Netronome Systems, Ltd. MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Fri, 19 Apr 2019 14:14:05 -0700, Alexei Starovoitov wrote: > > This reminds me, I'm not entirely clear on the need to propagate the > > zext through stack slots... Pointers are guaranteed to be 64bit, we > > don't save parentage on scalars (AFAICT), > > scalars have parentage chain too. > we don't track them precisely when they're spilled to stack. > That actually caused an issue recently when valid program was rejected, > so we might add a feature to track full contents of scalars in the stack. Interesting.. > > why not pass REG_LIVE_READ > > or READ64 to mark_reg_read() from stack_read? > > can we agree on only two states first ? ;) Yess, the LIVE_READ was thought to be more of a mask for those accesses that only care about "any read" being set, to be honest. As you said read64 is a strict superset of read32. Keeping the name REG_LIVE_READ, rather than REG_LIVE_READ_ANY or _MASK let us leave some of the existing code untouched. Jiong's original idea was to add a read32, and have read mean read64. I think you said we should have read32 and read64 flags, but clear read32 once read64 gets set? SGTM!