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 C1ADAC433EF for ; Mon, 21 Mar 2022 23:26:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232804AbiCUX2H (ORCPT ); Mon, 21 Mar 2022 19:28:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233304AbiCUX2B (ORCPT ); Mon, 21 Mar 2022 19:28:01 -0400 Received: from mail-il1-x136.google.com (mail-il1-x136.google.com [IPv6:2607:f8b0:4864:20::136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8FE035F191 for ; Mon, 21 Mar 2022 16:24:25 -0700 (PDT) Received: by mail-il1-x136.google.com with SMTP id b9so11402607ila.8 for ; Mon, 21 Mar 2022 16:24:25 -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=D2haUQ1GjLsXX9PM3Hfh9XGw56TWMfJ53nTjS8+8VGw=; b=l8y0F5br4MxmyWAiDca7uHiIHugE+MChtDmsU7/sMkTODFAJ1SYqrdTdvECCnHtD3A dkMxrFgyjfpyU5Yzhddys4LvLLgHcScMkfgcq2b7zSjHZha7EWzmU6xFIPpeCNG/z5EE l+qwhitOBrCg0wBgL/BtPE07+ECo2D4gHz9Rs6IpOXYTIc0dfvLiFnzDpo4qq+bdemBl xPUir3JpQp6tROr0xNIvnctvO5y7jK3tZ2vQE/hoNb7dBbB9uTSYykVbxO1KdICgO3CU +NShcUt2MRKux1KLssJhEC54DeYp5LHCdrEUREg8P33ZHuBW/uwN7Xi1bFtnc/1z8gRd LSqw== 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=D2haUQ1GjLsXX9PM3Hfh9XGw56TWMfJ53nTjS8+8VGw=; b=tBAz34W4n5Qrb6W4WVaz9TWz9oPpufMKA0u8GDpAvdui5hQXIMjGxnHazD3ZR/5lbi RjKStMMTWU5NUOvNE31+svPDEMZ2aUMJcL3EM9a2EnRfukKqUHDwCgjQ+l4ynJbGVlHQ 4QYXdnmuLOHQOSvByUfmxc139LhgW9Rfi54coMoEn1VO4TJmt3JkeZpc+pcKyCf/SeXA iYVEumlbMupcdOsPWk2XXLcu04/Q591smSqmVXX6bPAnwFRnJIUJo5QYRDwg6R6Yssvk Ua+zBu7v7EpzIEA2rvRaTSC+vm3NwBNg3Za/3Ui6mA48/uLx//45fl5Q+oBcpkMyVpFR w/Nw== X-Gm-Message-State: AOAM5316AH1FuVDoHAnAO5Vt/ZIYQO1dJfp4qRZ1aMwG6Nmtq7gWWJ59 0tUKRwHEXj/VFM0bZ6CTMSMv077YU1BP/uU0OuM= X-Google-Smtp-Source: ABdhPJxziJ63eIp0miJtwq1DbZoj12tsQJSayn5MmqyxBlutwxo/QqPfG2WvDyHWKK+hDYZd8jrkGV6cJd0QYyTd1ds= X-Received: by 2002:a92:c568:0:b0:2c8:8dd:e8bf with SMTP id b8-20020a92c568000000b002c808dde8bfmr6650758ilj.98.1647905064983; Mon, 21 Mar 2022 16:24:24 -0700 (PDT) MIME-Version: 1.0 References: <20220316004231.1103318-1-kuifeng@fb.com> <20220316004231.1103318-4-kuifeng@fb.com> <20220318191332.7qsztafrjyu7bjtc@ast-mbp> In-Reply-To: <20220318191332.7qsztafrjyu7bjtc@ast-mbp> From: Andrii Nakryiko Date: Mon, 21 Mar 2022 16:24:13 -0700 Message-ID: Subject: Re: [PATCH bpf-next v2 3/4] bpf, x86: Support BPF cookie for fentry/fexit/fmod_ret. To: Alexei Starovoitov Cc: Kui-Feng Lee , bpf , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Fri, Mar 18, 2022 at 12:13 PM Alexei Starovoitov wrote: > > On Tue, Mar 15, 2022 at 05:42:30PM -0700, Kui-Feng Lee wrote: > > Add a bpf_cookie field to attach a cookie to an instance of struct > > bpf_link. The cookie of a bpf_link will be installed when calling the > > associated program to make it available to the program. > > > > Signed-off-by: Kui-Feng Lee > > --- > > arch/x86/net/bpf_jit_comp.c | 4 ++-- > > include/linux/bpf.h | 1 + > > include/uapi/linux/bpf.h | 1 + > > kernel/bpf/syscall.c | 11 +++++++---- > > kernel/trace/bpf_trace.c | 17 +++++++++++++++++ > > tools/include/uapi/linux/bpf.h | 1 + > > tools/lib/bpf/bpf.c | 14 ++++++++++++++ > > tools/lib/bpf/bpf.h | 1 + > > tools/lib/bpf/libbpf.map | 1 + > > 9 files changed, 45 insertions(+), 6 deletions(-) > > please split kernel and libbpf changes into two different patches. > +1 > > diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c > > index f69ce3a01385..dbbf09c84c21 100644 > > --- a/tools/lib/bpf/bpf.c > > +++ b/tools/lib/bpf/bpf.c > > @@ -1133,6 +1133,20 @@ int bpf_raw_tracepoint_open(const char *name, int prog_fd) > > return libbpf_err_errno(fd); > > } > > > > +int bpf_raw_tracepoint_cookie_open(const char *name, int prog_fd, __u64 bpf_cookie) > > lets introduce opts style to raw_tp_open instead. I remember I brought this up earlier, but I forgot the outcome. What if don't touch BPF_RAW_TRACEPOINT_OPEN and instead allow to create all the same links through more universal BPF_LINK_CREATE command. And only there we add bpf_cookie? There are few advantages: 1. We can separate raw_tracepoint and trampoline-based programs more cleanly in UAPI (it will be two separate structs: link_create.raw_tp with raw tracepoint name vs link_create.trampoline, or whatever the name, with cookie and stuff). Remember that raw_tp won't support bpf_cookie for now, so it would be another advantage not to promise cookie in UAPI. 2. libbpf can be smart enough to pick either RAW_TRACEPOINT_OPEN (and reject it if bpf_cookie is non-zero) or BPF_LINK_CREATE, depending on kernel support. So users would need to only use bpf_link_create() moving forward with all the backwards compatibility preserved. > > > +{ > > + union bpf_attr attr; > > + int fd; > > + > > + memset(&attr, 0, sizeof(attr)); > > + attr.raw_tracepoint.name = ptr_to_u64(name); > > + attr.raw_tracepoint.prog_fd = prog_fd; > > + attr.raw_tracepoint.bpf_cookie = bpf_cookie; > > + > > + fd = sys_bpf_fd(BPF_RAW_TRACEPOINT_OPEN, &attr, sizeof(attr)); > > + return libbpf_err_errno(fd); > > +} > > + > > int bpf_btf_load(const void *btf_data, size_t btf_size, const struct bpf_btf_load_opts *opts) > > { > > const size_t attr_sz = offsetofend(union bpf_attr, btf_log_level); > > diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h > > index 5253cb4a4c0a..23bebcdaf23b 100644 > > --- a/tools/lib/bpf/bpf.h > > +++ b/tools/lib/bpf/bpf.h > > @@ -477,6 +477,7 @@ LIBBPF_API int bpf_prog_query(int target_fd, enum bpf_attach_type type, > > __u32 query_flags, __u32 *attach_flags, > > __u32 *prog_ids, __u32 *prog_cnt); > > LIBBPF_API int bpf_raw_tracepoint_open(const char *name, int prog_fd); > > +LIBBPF_API int bpf_raw_tracepoint_cookie_open(const char *name, int prog_fd, __u64 bpf_cookie); > > LIBBPF_API int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, > > __u32 *buf_len, __u32 *prog_id, __u32 *fd_type, > > __u64 *probe_offset, __u64 *probe_addr); > > diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map > > index df1b947792c8..20f947a385fa 100644 > > --- a/tools/lib/bpf/libbpf.map > > +++ b/tools/lib/bpf/libbpf.map > > @@ -434,6 +434,7 @@ LIBBPF_0.7.0 { > > bpf_xdp_detach; > > bpf_xdp_query; > > bpf_xdp_query_id; > > + bpf_raw_tracepoint_cookie_open; this (if still needed) should go into 0.8.0 section > > libbpf_probe_bpf_helper; > > libbpf_probe_bpf_map_type; > > libbpf_probe_bpf_prog_type; > > -- > > 2.30.2 > > > > --