From patchwork Wed Feb 22 06:07:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joanne Koong X-Patchwork-Id: 13148742 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 2BF66C64EC4 for ; Wed, 22 Feb 2023 06:08:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230171AbjBVGIf (ORCPT ); Wed, 22 Feb 2023 01:08:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229464AbjBVGIe (ORCPT ); Wed, 22 Feb 2023 01:08:34 -0500 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7CF34271E for ; Tue, 21 Feb 2023 22:08:33 -0800 (PST) Received: by devvm20151.prn0.facebook.com (Postfix, from userid 115148) id 4ECCDF67CD2; Tue, 21 Feb 2023 22:08:19 -0800 (PST) From: Joanne Koong To: bpf@vger.kernel.org Cc: martin.lau@kernel.org, andrii@kernel.org, ast@kernel.org, memxor@gmail.com, daniel@iogearbox.net, netdev@vger.kernel.org, kernel-team@fb.com, toke@kernel.org, Joanne Koong Subject: [PATCH v11 bpf-next 00/10] Add skb + xdp dynptrs Date: Tue, 21 Feb 2023 22:07:37 -0800 Message-Id: <20230222060747.2562549-1-joannelkoong@gmail.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Joanne Koong This patchset is the 2nd in the dynptr series. The 1st can be found here [0]. This patchset adds skb and xdp type dynptrs, which have two main benefits for packet parsing: * allowing operations on sizes that are not statically known at compile-time (eg variable-sized accesses). * more ergonomic and less brittle iteration through data (eg does not need manual if checking for being within bounds of data_end) When comparing the differences in runtime for packet parsing without dynptrs vs. with dynptrs, there is no noticeable difference. Patch 9 contains more details as well as examples of how to use skb and xdp dynptrs. [0] https://lore.kernel.org/bpf/20220523210712.3641569-1-joannelkoong@gmail.com/ --- Changelog: v10 = https://lore.kernel.org/bpf/20230216225524.1192789-1-joannelkoong@gmail.com/ v10 -> v11: * Reject bpf_dynptr_slice_rdwr() for non-writable progs at load time instead of runtime * Add additional patch (__uninit kfunc annotation) * Expand on documentation * Add bpf_dynptr_write() calls for persisting writes in tests v9 = https://lore.kernel.org/bpf/20230127191703.3864860-1-joannelkoong@gmail.com/ v9 -> v10: * Add bpf_dynptr_slice and bpf_dynptr_slice_rdwr interface * Add some more tests * Split up patchset into more parts to make it easier to review v8 = https://lore.kernel.org/bpf/20230126233439.3739120-1-joannelkoong@gmail.com/ v8 -> v9: * Fix dynptr_get_type() to check non-stack dynptrs v7 = https://lore.kernel.org/bpf/20221021011510.1890852-1-joannelkoong@gmail.com/ v7 -> v8: * Change helpers to kfuncs * Add 2 new patches (1/5 and 2/5) v6 = https://lore.kernel.org/bpf/20220907183129.745846-1-joannelkoong@gmail.com/ v6 -> v7 * Change bpf_dynptr_data() to return read-only data slices if the skb prog is read-only (Martin) * Add test "skb_invalid_write" to test that writes to rd-only data slices are rejected v5 = https://lore.kernel.org/bpf/20220831183224.3754305-1-joannelkoong@gmail.com/ v5 -> v6 * Address kernel test robot errors by static inlining v4 = https://lore.kernel.org/bpf/20220822235649.2218031-1-joannelkoong@gmail.com/ v4 -> v5 * Address kernel test robot errors for configs w/out CONFIG_NET set * For data slices, return PTR_TO_MEM instead of PTR_TO_PACKET (Kumar) * Split selftests into subtests (Andrii) * Remove insn patching. Use rdonly and rdwr protos for dynptr skb construction (Andrii) * bpf_dynptr_data() returns NULL for rd-only dynptrs. There will be a separate bpf_dynptr_data_rdonly() added later (Andrii and Kumar) v3 = https://lore.kernel.org/bpf/20220822193442.657638-1-joannelkoong@gmail.com/ v3 -> v4 * Forgot to commit --amend the kernel test robot error fixups v2 = https://lore.kernel.org/bpf/20220811230501.2632393-1-joannelkoong@gmail.com/ v2 -> v3 * Fix kernel test robot build test errors v1 = https://lore.kernel.org/bpf/20220726184706.954822-1-joannelkoong@gmail.com/ v1 -> v2 * Return data slices to rd-only skb dynptrs (Martin) * bpf_dynptr_write allows writes to frags for skb dynptrs, but always invalidates associated data slices (Martin) * Use switch casing instead of ifs (Andrii) * Use 0xFD for experimental kind number in the selftest (Zvi) * Put selftest conversions w/ dynptrs into new files (Alexei) * Add new selftest "test_cls_redirect_dynptr.c" Joanne Koong (10): bpf: Support "sk_buff" and "xdp_buff" as valid kfunc arg types bpf: Refactor process_dynptr_func bpf: Allow initializing dynptrs in kfuncs bpf: Define no-ops for externally called bpf dynptr functions bpf: Refactor verifier dynptr into get_dynptr_arg_reg bpf: Add __uninit kfunc annotation bpf: Add skb dynptrs bpf: Add xdp dynptrs bpf: Add bpf_dynptr_slice and bpf_dynptr_slice_rdwr selftests/bpf: tests for using dynptrs to parse skb and xdp buffers Documentation/bpf/kfuncs.rst | 17 + include/linux/bpf.h | 95 +- include/linux/bpf_verifier.h | 3 - include/linux/filter.h | 46 + include/uapi/linux/bpf.h | 18 +- kernel/bpf/btf.c | 22 + kernel/bpf/helpers.c | 221 +++- kernel/bpf/verifier.c | 379 +++++-- net/core/filter.c | 108 +- tools/include/uapi/linux/bpf.h | 18 +- .../selftests/bpf/prog_tests/cls_redirect.c | 25 + .../testing/selftests/bpf/prog_tests/dynptr.c | 69 +- .../selftests/bpf/prog_tests/l4lb_all.c | 2 + .../bpf/prog_tests/parse_tcp_hdr_opt.c | 93 ++ .../selftests/bpf/prog_tests/xdp_attach.c | 11 +- .../testing/selftests/bpf/progs/dynptr_fail.c | 295 +++++- .../selftests/bpf/progs/dynptr_success.c | 57 +- .../bpf/progs/test_cls_redirect_dynptr.c | 984 ++++++++++++++++++ .../bpf/progs/test_l4lb_noinline_dynptr.c | 492 +++++++++ .../bpf/progs/test_parse_tcp_hdr_opt.c | 119 +++ .../bpf/progs/test_parse_tcp_hdr_opt_dynptr.c | 118 +++ .../selftests/bpf/progs/test_xdp_dynptr.c | 263 +++++ .../selftests/bpf/test_tcp_hdr_options.h | 1 + 23 files changed, 3274 insertions(+), 182 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/parse_tcp_hdr_opt.c create mode 100644 tools/testing/selftests/bpf/progs/test_cls_redirect_dynptr.c create mode 100644 tools/testing/selftests/bpf/progs/test_l4lb_noinline_dynptr.c create mode 100644 tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt.c create mode 100644 tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt_dynptr.c create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_dynptr.c