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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89373C43217 for ; Tue, 29 Mar 2022 16:26:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239633AbiC2Q2I (ORCPT ); Tue, 29 Mar 2022 12:28:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58222 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238973AbiC2Q1r (ORCPT ); Tue, 29 Mar 2022 12:27:47 -0400 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E9DDC229C85; Tue, 29 Mar 2022 09:26:03 -0700 (PDT) Received: by mail-pj1-x102d.google.com with SMTP id v4so18004494pjh.2; Tue, 29 Mar 2022 09:26:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=zSrzL4RcvPdwRrem0JkeQUvfghxscmF/IIS73/4ISuM=; b=bPfDbjpxT0DjSxL1JWnNIzaPLGLUUme9ZWh2cGwHb8l0KU6et+OSmZSHXDAfDMlBV7 x9enOeMebdZsaPVu+3jwjyR3vpUVE315M4onO3XK9p5P/ErHPsG9n/RzTrJM32YLmVB2 cjssIk65ai2vA3WifAewBN9c3HxMWnLGaE4Fs7X8RW48MOb4EFTFTm7EajCtTffqUZea BczMb7mH+NRyho4RPrfgnI7gwT47rolAYjj5kOyhWxinpzVAfA6CeoQBHcd/hFn0CqJ7 DXvT6jKqwuSmbYPA2nnwELtAawLRF2kERBojv9dTU5loc10Wx26v2/2fkrWPSaqxXx4N ZDiw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=zSrzL4RcvPdwRrem0JkeQUvfghxscmF/IIS73/4ISuM=; b=YhWl/AWyOvZFl2WiCZGbzG5Fcy0XW5gEzQ+3eozb58oNaDTxJjAVd91c03I20tsQt7 G90SUIOSuEDLfttOjksmPSfH7QTWBj97DPFULCJfLBhuXjrI3WufwbZcJZd/C4TTB97P F/F+qrKtKruIkmYEVWAqSez4LUALg3tbYro8NX1YUeJk8OWLrXXIZ6/jTDQ1gYShoYKQ uawOx0ACH34wUOpLxuyLlPMKUboxICi9bIa5tFB+OLaaq8x0lXlBD5xvLPRv/OUBU2/i RPlCTER0dRR7FU5WGr5BdKZ/RygXsYEu70GE4cGxHP0Rss8DVh5yj2Mxa23tJJp/zA6p Uy6g== X-Gm-Message-State: AOAM5313NtsQ++66AMAqUzELV9SF6cfcv1LdT4d7680McBSI5YnxZsjt E+vg3XcfGcHvWzRHK1zeRqk4gLk2W1HJ8/a34gY= X-Google-Smtp-Source: ABdhPJy1y4rAeGRjAUma3/+QC6ZygqH6gCxyxvl+xjD9wME0wCYbFyY6Gq6YQ7F/SN+20kvJeSyRdQJx/ECNTEFRVzA= X-Received: by 2002:a17:902:ba83:b0:154:727e:5fc5 with SMTP id k3-20020a170902ba8300b00154727e5fc5mr31922203pls.55.1648571163362; Tue, 29 Mar 2022 09:26:03 -0700 (PDT) MIME-Version: 1.0 References: <2059213643.196683.1648499088753.JavaMail.zimbra@efficios.com> <20220329002935.2869-1-beaub@linux.microsoft.com> <1014535694.197402.1648570634323.JavaMail.zimbra@efficios.com> In-Reply-To: <1014535694.197402.1648570634323.JavaMail.zimbra@efficios.com> From: Alexei Starovoitov Date: Tue, 29 Mar 2022 09:25:52 -0700 Message-ID: Subject: Re: Comments on new user events ABI To: Mathieu Desnoyers , Linus Torvalds , bpf , Network Development Cc: Beau Belgrave , Beau Belgrave , linux-arch , linux-kernel , linux-trace-devel , rostedt , Masami Hiramatsu , Alexei Starovoitov Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 29, 2022 at 9:17 AM Mathieu Desnoyers wrote: > > > > >> include/uapi/linux/user_events.h: > >> > >> struct user_bpf_iter { > >> > >> /* Offset of the data within the first iovec */ > >> __u32 iov_offset; > >> > >> /* Number of iovec structures */ > >> __u32 nr_segs; > >> > >> /* Pointer to iovec structures */ > >> const struct iovec *iov; > >> > >> ^ a pointer in a uapi header is usually a no-go. This should be a u64. > >> }; > >> > >> include/uapi/linux/user_events.h: > >> > >> struct user_bpf_context { > >> > >> /* Data type being passed (see union below) */ > >> __u32 data_type; > >> > >> /* Length of the data */ > >> __u32 data_len; > >> > >> /* Pointer to data, varies by data type */ > >> union { > >> /* Kernel data (data_type == USER_BPF_DATA_KERNEL) */ > >> void *kdata; > >> > >> /* User data (data_type == USER_BPF_DATA_USER) */ > >> void *udata; > >> > >> /* Direct iovec (data_type == USER_BPF_DATA_ITER) */ > >> struct user_bpf_iter *iter; > >> > >> ^ likewise for the 3 pointers above. Should be u64 in uapi headers. > >> }; > >> }; > >> > > > > The bpf structs are only used within a BPF program. At that point the pointer > > sizes should all align, right? > > I must admit I do not know enough about the eBPF uapi practices to answer this. > [CCing Alexei on this] Mathieu, Thanks for flagging. Whoever added this user_bpf* stuff please remove it immediately. It was never reviewed by bpf maintainers. It's a hard Nack to add a bpf interface to user_events.