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=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 E5BB2C433ED for ; Tue, 20 Apr 2021 02:20:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B1185611EE for ; Tue, 20 Apr 2021 02:20:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229711AbhDTCV3 (ORCPT ); Mon, 19 Apr 2021 22:21:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229601AbhDTCV3 (ORCPT ); Mon, 19 Apr 2021 22:21:29 -0400 Received: from mail-lj1-x229.google.com (mail-lj1-x229.google.com [IPv6:2a00:1450:4864:20::229]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5446BC06174A for ; Mon, 19 Apr 2021 19:20:58 -0700 (PDT) Received: by mail-lj1-x229.google.com with SMTP id a36so30871027ljq.8 for ; Mon, 19 Apr 2021 19:20:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=AO2qh75XltAhV+SOz3RxvN1LKvjGstw1tTi0Ol4m3/M=; b=I2nqrLpu51XsYzp2SkmQ60ZKPs8FqgMToMcGNirK4/SXdF2dTNYYvuhPXqFeqZv2ol 9ZfYdKiKxozGDuaYUTokCWMqHQSr4Xu/XQUMKyxpd0mFxgsgc99qG5PNfHMjNjzpuqef K69qstiGu8+MPClt4HO7k8fbFl/nLvi6+xulBCbQ6zYmvN+GSM6/edOVCrQsYcJvYBxX 8xo0f5YmfATjSKsMHuE4QI2mzUGiEu0Qpb0E6KyhnkolFOSnLaNayRD/yEa+jeVn4s7C SF7p2RfvUKVYTMVe8JIVEtXVl2hS3SD9kZ3dzWfG/3/Bgzo1s7iT3T8szvcuz1g9KdTM il6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=AO2qh75XltAhV+SOz3RxvN1LKvjGstw1tTi0Ol4m3/M=; b=Um7nokfM+GuNqP3XR6DK5au6z5luPuOkIE7lNo+JNvntB4FlivP3mOFKcqK6ioq+zH 6cxuWKPKP5Ug6xbukHaHPgCXPurJHDaw+KMybmxGxTLdsvh32175/MEJvXUo2kka9Jtw lO9O7LX3HXhTNaQLvLL0duF9LSPye7BGadUy7toHyyXFI7nPB5eIlLnpwGjirWNn/v1E FwhS0+t//YlsujyrgCkC5lqNFbRdUq/B1t0kJebUXeRZvoVppXY7xtC5KUHegInK50UC WFSB5+36jGP31KjlSlYPrzW5Sv/uNyDDeccNdm+SyEbu1hyX4tnFZYaN/1Jchh29DTgY 5vQw== X-Gm-Message-State: AOAM533a9Fl4kDoGQOC6UJ09DK8WOkwexyt8aWrR9nnMrCFDhyy2Uus2 ChDg/X323delOaCNCUePYna79fWpBXzZ83Bt3tU= X-Google-Smtp-Source: ABdhPJx6eNSzy5Q5yQudc4qio2OJkfR2rKTi9u/41VZjuMY44V1fbpsSO3pATU63NmcsdV3BZAI2oUQ8gfcIhL/JmKE= X-Received: by 2002:a2e:3511:: with SMTP id z17mr9499029ljz.32.1618885256913; Mon, 19 Apr 2021 19:20:56 -0700 (PDT) MIME-Version: 1.0 References: <20210416204704.2816874-1-davemarchevsky@fb.com> In-Reply-To: <20210416204704.2816874-1-davemarchevsky@fb.com> From: Alexei Starovoitov Date: Mon, 19 Apr 2021 19:20:45 -0700 Message-ID: Subject: Re: [PATCH bpf-next v2 0/3] bpf: refine retval for bpf_get_task_stack helper To: Dave Marchevsky Cc: bpf , Kernel Team , Alexei Starovoitov , Daniel Borkmann , Song Liu , Yonghong Song Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Fri, Apr 16, 2021 at 1:47 PM Dave Marchevsky wrote: > > Similarly to the bpf_get_stack helper, bpf_get_task_stack's return value > can be more tightly bound by the verifier - it's the number of bytes > written to a user-supplied buffer, or a negative error value. Currently > the verifier believes bpf_task_get_stack's retval bounds to be unknown, > requiring extraneous bounds checking to remedy. > > Adding it to do_refine_retval_range fixes the issue, as evidenced by > new selftests which fail to load if retval bounds are not refined. > > v2: Addressed comment nit in patch 3 Applied. Thanks