From patchwork Sun Mar 28 11:26:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 410756 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=-14.0 required=3.0 tests=BAYES_00, INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 6E116C433E4 for ; Sun, 28 Mar 2021 11:27:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F1FC61972 for ; Sun, 28 Mar 2021 11:27:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231260AbhC1L1I convert rfc822-to-8bit (ORCPT ); Sun, 28 Mar 2021 07:27:08 -0400 Received: from us-smtp-delivery-44.mimecast.com ([205.139.111.44]:40833 "EHLO us-smtp-delivery-44.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230526AbhC1L0s (ORCPT ); Sun, 28 Mar 2021 07:26:48 -0400 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-146-JzK_RUyqOJ2QtYWoe_YUBQ-1; Sun, 28 Mar 2021 07:26:41 -0400 X-MC-Unique: JzK_RUyqOJ2QtYWoe_YUBQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id F41D4107ACCA; Sun, 28 Mar 2021 11:26:39 +0000 (UTC) Received: from krava.redhat.com (unknown [10.40.192.12]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5D7BD19C66; Sun, 28 Mar 2021 11:26:37 +0000 (UTC) From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= Subject: [RFC PATCH bpf-next 1/4] bpf: Allow trampoline re-attach Date: Sun, 28 Mar 2021 13:26:26 +0200 Message-Id: <20210328112629.339266-2-jolsa@kernel.org> In-Reply-To: <20210328112629.339266-1-jolsa@kernel.org> References: <20210328112629.339266-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jolsa@kernel.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Currently we don't allow re-attaching of trampolines. Once it's detached, it can't be re-attach even when the program is still loaded. Adding the possibility to re-attach the loaded tracing kernel program. Signed-off-by: Jiri Olsa Acked-by: Song Liu Acked-by: Toke Høiland-Jørgensen --- kernel/bpf/syscall.c | 25 +++++++++++++++++++------ kernel/bpf/trampoline.c | 2 +- 2 files changed, 20 insertions(+), 7 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 9603de81811a..e14926b2e95a 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2645,14 +2645,27 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog, * target_btf_id using the link_create API. * * - if tgt_prog == NULL when this function was called using the old - * raw_tracepoint_open API, and we need a target from prog->aux - * - * The combination of no saved target in prog->aux, and no target - * specified on load is illegal, and we reject that here. + * raw_tracepoint_open API, and we need a target from prog->aux + * + * The combination of no saved target in prog->aux, and no target + * specified on is legal only for tracing programs re-attach, rest + * is illegal, and we reject that here. */ if (!prog->aux->dst_trampoline && !tgt_prog) { - err = -ENOENT; - goto out_unlock; + /* + * Allow re-attach for tracing programs, if it's currently + * linked, bpf_trampoline_link_prog will fail. + */ + if (prog->type != BPF_PROG_TYPE_TRACING) { + err = -ENOENT; + goto out_unlock; + } + if (!prog->aux->attach_btf) { + err = -EINVAL; + goto out_unlock; + } + btf_id = prog->aux->attach_btf_id; + key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); } if (!prog->aux->dst_trampoline || diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 4aa8b52adf25..0d937c63fc22 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -467,7 +467,7 @@ int bpf_trampoline_unlink_prog(struct bpf_prog *prog, struct bpf_trampoline *tr) tr->extension_prog = NULL; goto out; } - hlist_del(&prog->aux->tramp_hlist); + hlist_del_init(&prog->aux->tramp_hlist); tr->progs_cnt[kind]--; err = bpf_trampoline_update(tr); out: From patchwork Sun Mar 28 11:26:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 410755 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=-14.0 required=3.0 tests=BAYES_00, INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 B597EC433E9 for ; Sun, 28 Mar 2021 11:27:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A45FA61972 for ; Sun, 28 Mar 2021 11:27:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231305AbhC1L1J convert rfc822-to-8bit (ORCPT ); Sun, 28 Mar 2021 07:27:09 -0400 Received: from us-smtp-delivery-44.mimecast.com ([207.211.30.44]:29708 "EHLO us-smtp-delivery-44.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231143AbhC1L0x (ORCPT ); Sun, 28 Mar 2021 07:26:53 -0400 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-179-luRFWaqMOFGaRtWxzJ6aUQ-1; Sun, 28 Mar 2021 07:26:49 -0400 X-MC-Unique: luRFWaqMOFGaRtWxzJ6aUQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0F52A8030A1; Sun, 28 Mar 2021 11:26:47 +0000 (UTC) Received: from krava.redhat.com (unknown [10.40.192.12]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1DDA019C66; Sun, 28 Mar 2021 11:26:42 +0000 (UTC) From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= Subject: [RFC PATCH bpf-next 3/4] selftests/bpf: Add re-attach test to fexit_test Date: Sun, 28 Mar 2021 13:26:28 +0200 Message-Id: <20210328112629.339266-4-jolsa@kernel.org> In-Reply-To: <20210328112629.339266-1-jolsa@kernel.org> References: <20210328112629.339266-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jolsa@kernel.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Adding the test to re-attach (detach/attach again) tracing fexit programs, plus check that already linked program can't be attached again. Fixing the number of check-ed results, which should be 8. Signed-off-by: Jiri Olsa --- .../selftests/bpf/prog_tests/fexit_test.c | 58 ++++++++++++++----- 1 file changed, 45 insertions(+), 13 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/fexit_test.c b/tools/testing/selftests/bpf/prog_tests/fexit_test.c index 78d7a2765c27..6666c5105f1e 100644 --- a/tools/testing/selftests/bpf/prog_tests/fexit_test.c +++ b/tools/testing/selftests/bpf/prog_tests/fexit_test.c @@ -3,20 +3,13 @@ #include #include "fexit_test.skel.h" -void test_fexit_test(void) +static __u32 duration; + +static int fexit_test(struct fexit_test *fexit_skel) { - struct fexit_test *fexit_skel = NULL; int err, prog_fd, i; - __u32 duration = 0, retval; __u64 *result; - - fexit_skel = fexit_test__open_and_load(); - if (CHECK(!fexit_skel, "fexit_skel_load", "fexit skeleton failed\n")) - goto cleanup; - - err = fexit_test__attach(fexit_skel); - if (CHECK(err, "fexit_attach", "fexit attach failed: %d\n", err)) - goto cleanup; + __u32 retval; prog_fd = bpf_program__fd(fexit_skel->progs.test1); err = bpf_prog_test_run(prog_fd, 1, NULL, 0, @@ -26,12 +19,51 @@ void test_fexit_test(void) err, errno, retval, duration); result = (__u64 *)fexit_skel->bss; - for (i = 0; i < 6; i++) { + for (i = 0; i < 8; i++) { if (CHECK(result[i] != 1, "result", "fexit_test%d failed err %lld\n", i + 1, result[i])) - goto cleanup; + return -1; } + /* zero results for re-attach test */ + for (i = 0; i < 8; i++) + result[i] = 0; + return 0; +} + +void test_fexit_test(void) +{ + struct fexit_test *fexit_skel = NULL; + struct bpf_link *link; + int err; + + fexit_skel = fexit_test__open_and_load(); + if (CHECK(!fexit_skel, "fexit_skel_load", "fexit skeleton failed\n")) + goto cleanup; + + err = fexit_test__attach(fexit_skel); + if (CHECK(err, "fexit_attach", "fexit attach failed: %d\n", err)) + goto cleanup; + + err = fexit_test(fexit_skel); + if (CHECK(err, "fexit_test", "exit test failed: %d\n", err)) + goto cleanup; + + fexit_test__detach(fexit_skel); + + /* Re-attach and test again */ + err = fexit_test__attach(fexit_skel); + if (CHECK(err, "fexit_attach", "fexit attach failed: %d\n", err)) + goto cleanup; + + link = bpf_program__attach(fexit_skel->progs.test1); + if (CHECK(!IS_ERR(link), "attach_fexit re-attach without detach", + "err: %ld\n", PTR_ERR(link))) + goto cleanup; + + err = fexit_test(fexit_skel); + CHECK(err, "fexit_test", "fexit test failed: %d\n", err); + cleanup: fexit_test__destroy(fexit_skel); }