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=-11.8 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 D9C6EC43461 for ; Thu, 3 Sep 2020 22:33:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB29820716 for ; Thu, 3 Sep 2020 22:33:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="jg0PYIL8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728657AbgICWdi (ORCPT ); Thu, 3 Sep 2020 18:33:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54372 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728134AbgICWdg (ORCPT ); Thu, 3 Sep 2020 18:33:36 -0400 Received: from mail-qk1-x749.google.com (mail-qk1-x749.google.com [IPv6:2607:f8b0:4864:20::749]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 56F1BC061244 for ; Thu, 3 Sep 2020 15:33:36 -0700 (PDT) Received: by mail-qk1-x749.google.com with SMTP id 139so2474744qkl.11 for ; Thu, 03 Sep 2020 15:33:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:message-id:mime-version:subject:from:to:cc; bh=fTZ15syT0j93m0JsqPQnX1nkgQUuupGOrvog1ui3uCg=; b=jg0PYIL8/uxMLhBlBcANr9ZodHPKPSPhUdh/T7gtdwPYtHZdEBIqw++C06tS8hxt7K FQyODpWmDbyei1fD7rLkUD5zFFclZ0s8B9BFtTRjSVxAaF6DQovV4Tjag5YScRBg3rkr pz/qPj2xm0HVcn8B8Iug60bEEaZkRnD6g3sQRlc+Vo+zmID1DkdotqvR8FtOUdizKqvc 3AZBfgYuZCtK8DfaBtPFmUcNC8RoC5gAUxZe6ZBg+vFjnvwS/sFbWMb0dJQr1LxwBeMy bMDihACraTfSF8FFU0JmiMN/uuQRlyc1F25wtC9BTlvZuCn4DvWUsLnVZIYwezb9zoHh BGbg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:message-id:mime-version:subject:from :to:cc; bh=fTZ15syT0j93m0JsqPQnX1nkgQUuupGOrvog1ui3uCg=; b=GUSvR7kburJrpuCFQBFqvLsYc2zOrKBQmlPFkiN4PmWubSftTwZlSUiVWrLov3eQMT yjPfIwFq8aiR42jVO0q4E4qqr/D1HFkaVg3gWa+vWxsyRLrcFFGXVr8As9VhilxZfUAK VINRkoV8x0+B+NjeKIr+CX3SmRNon261t58DYl6MLA8b2tvwxNJevd3jx2d2IdlnQZqq g5nZoTJltiJ8Tx8T6EFFsyX5oNIwlpdwBNFjd0JSFhZP8B2Occv1ZOJANcKUbd7KZArp XCADse8oNZiregUC+qqTgLR0UgrDvZCPGNfHqBMnCB9CfSqycEf2UPjNC2T5XvvTaCgC t6Qw== X-Gm-Message-State: AOAM5307hl7QzHBJFK0P30VubiLlck8ozpUeQrrawBHC2a4OC6+bBKxG NlvwVi/dPaA8Mo8C+FizYmAp+tZM5NQ= X-Google-Smtp-Source: ABdhPJwfdmRl7fQrs6iAGmzxMo4s6aY3ueBPiwa8QHmB+91ldNEpNzmWD5pOtS17ypkemV/n1Ula7lNNngU= X-Received: from haoluo.svl.corp.google.com ([2620:15c:2cd:202:f693:9fff:fef4:e444]) (user=haoluo job=sendgmr) by 2002:a0c:f48e:: with SMTP id i14mr4176950qvm.9.1599172415472; Thu, 03 Sep 2020 15:33:35 -0700 (PDT) Date: Thu, 3 Sep 2020 15:33:26 -0700 Message-Id: <20200903223332.881541-1-haoluo@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.28.0.526.ge36021eeef-goog Subject: [PATCH bpf-next v2 0/6] bpf: BTF support for ksyms From: Hao Luo To: netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Shuah Khan , Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Quentin Monnet , Hao Luo , Steven Rostedt , Ingo Molnar , Andrey Ignatov , Jakub Sitnicki Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org v1 -> v2: - Move check_pseudo_btf_id from check_ld_imm() to replace_map_fd_with_map_ptr() and rename the latter. - Add bpf_this_cpu_ptr(). - Use bpf_core_types_are_compat() in libbpf.c for checking type compatibility. - Rewrite typed ksym extern type in BTF with int to save space. - Minor revision of bpf_per_cpu_ptr()'s comments. - Avoid using long in tests that use skeleton. - Refactored test_ksyms.c by moving kallsyms_find() to trace_helpers.c - Fold the patches that sync include/linux/uapi and tools/include/linux/uapi. rfc -> v1: - Encode VAR's btf_id for PSEUDO_BTF_ID. - More checks in verifier. Checking the btf_id passed as PSEUDO_BTF_ID is valid VAR, its name and type. - Checks in libbpf on type compatibility of ksyms. - Add bpf_per_cpu_ptr() to access kernel percpu vars. Introduced new ARG and RET types for this helper. This patch series extends the previously added __ksym externs with btf support. Right now the __ksym externs are treated as pure 64-bit scalar value. Libbpf replaces ld_imm64 insn of __ksym by its kernel address at load time. This patch series extend those externs with their btf info. Note that btf support for __ksym must come with the kernel btf that has VARs encoded to work properly. The corresponding chagnes in pahole is available at [1] (with a fix at [2] for gcc 4.9+). The first 3 patches in this series add support for general kernel global variables, which include verifier checking (01/06), libpf support (02/06) and selftests for getting typed ksym extern's kernel address (03/06). The next 3 patches extends that capability further by introducing helpers bpf_per_cpu_ptr() and bpf_this_cpu_ptr(), which allows accessing kernel percpu variables correctly (04/06 and 05/06). The tests of this feature were performed against pahole that is extended with [1] and [2]. For kernel BTF that does not have VARs encoded, the selftests will be skipped. [1] https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=f3d9054ba8ff1df0fc44e507e3a01c0964cabd42 [2] https://www.spinics.net/lists/dwarves/msg00451.html Hao Luo (6): bpf: Introduce pseudo_btf_id bpf/libbpf: BTF support for typed ksyms bpf/selftests: ksyms_btf to test typed ksyms bpf: Introduce bpf_per_cpu_ptr() bpf: Introduce bpf_this_cpu_ptr() bpf/selftests: Test for bpf_per_cpu_ptr() and bpf_this_cpu_ptr() include/linux/bpf.h | 4 + include/linux/bpf_verifier.h | 4 + include/linux/btf.h | 26 +++ include/uapi/linux/bpf.h | 69 ++++++- kernel/bpf/btf.c | 25 --- kernel/bpf/verifier.c | 176 +++++++++++++++++- kernel/trace/bpf_trace.c | 32 ++++ tools/include/uapi/linux/bpf.h | 69 ++++++- tools/lib/bpf/libbpf.c | 116 ++++++++++-- .../testing/selftests/bpf/prog_tests/ksyms.c | 31 +-- .../selftests/bpf/prog_tests/ksyms_btf.c | 73 ++++++++ .../selftests/bpf/progs/test_ksyms_btf.c | 49 +++++ tools/testing/selftests/bpf/trace_helpers.c | 26 +++ tools/testing/selftests/bpf/trace_helpers.h | 4 + 14 files changed, 615 insertions(+), 89 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/ksyms_btf.c create mode 100644 tools/testing/selftests/bpf/progs/test_ksyms_btf.c -- 2.28.0.526.ge36021eeef-goog