From patchwork Sun Sep 29 13:27:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leon Hwang X-Patchwork-Id: 13815092 X-Patchwork-Delegate: bpf@iogearbox.net Received: from out-186.mta1.migadu.com (out-186.mta1.migadu.com [95.215.58.186]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A478D149DE4 for ; Sun, 29 Sep 2024 13:28:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.186 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727616511; cv=none; b=sCX3HZl55x4ooHFRzN7GlQyVYfWFZazwaLiJeiWv/4xrjKH9ziHS9dojV2my5h/nPoFcKvI80eeMjjKjy7r6jGTlOiLIEX5arby1vvLQlS4Jc/FZ2u63wsVRs/+Q8+Lbkrv6Zgx6i9F4QuBHeWuMUI17kIs2KcxvqqBGGLPyJrM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727616511; c=relaxed/simple; bh=oH68Zyi+ZvXqOyoe80TSA2W6sdYG6p/562blmsNweoo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZoDZsunia8aEhnAq9OYEy5ULzAQHYC93NiQ1AMtLB5zJzqjWwRkp9gRtleesBSzbhmf/WqLKBCmiTG3Zdw7CahJmYWLrmcuUTjgQZtKTJOfJbLzrWJ9cbiA3ndR3epDXDXOUp5Zva9Fzz0of1rmbGg1gKna9JAQAvvB9XOtkAQo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=J8tNJK6p; arc=none smtp.client-ip=95.215.58.186 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="J8tNJK6p" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1727616507; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+5jlWI/hvCd4YL4748QdUtZcIBNEyBMGmbw6HMTY2A0=; b=J8tNJK6pGF8hMXAj78yS8OvW2bSWTNsaEmswH3ahe0/qNRBkRpL+it1ArRLtG+wXMgJjDK SDXD9e1cgRHHw9kRk/JP8DCh/aBUXOTQYTZWngb32uQtzymHFq4shlCBet1Oew1rv8n/Zd jmRgWN7RTNLQcwaKFebTs5xnKWoJnmg= From: Leon Hwang To: bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, toke@redhat.com, martin.lau@kernel.org, yonghong.song@linux.dev, puranjay@kernel.org, xukuohai@huaweicloud.com, eddyz87@gmail.com, iii@linux.ibm.com, leon.hwang@linux.dev, kernel-patches-bot@fb.com Subject: [PATCH bpf-next v4 3/4] selftests/bpf: Add a test case to confirm a tailcall infinite loop issue has been prevented Date: Sun, 29 Sep 2024 21:27:56 +0800 Message-ID: <20240929132757.79826-4-leon.hwang@linux.dev> In-Reply-To: <20240929132757.79826-1-leon.hwang@linux.dev> References: <20240929132757.79826-1-leon.hwang@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Patchwork-Delegate: bpf@iogearbox.net cd tools/testing/selftests/bpf; ./test_progs -t tailcalls 335/26 tailcalls/tailcall_bpf2bpf_freplace:OK 335 tailcalls:OK Summary: 1/26 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Leon Hwang --- .../selftests/bpf/prog_tests/tailcalls.c | 99 ++++++++++++++++++- .../testing/selftests/bpf/progs/tc_bpf2bpf.c | 24 ++++- 2 files changed, 119 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/tailcalls.c b/tools/testing/selftests/bpf/prog_tests/tailcalls.c index 21c5a37846ade..fa3f3bb11b098 100644 --- a/tools/testing/selftests/bpf/prog_tests/tailcalls.c +++ b/tools/testing/selftests/bpf/prog_tests/tailcalls.c @@ -1525,7 +1525,8 @@ static void test_tailcall_freplace(void) prog_fd = bpf_program__fd(tc_skel->progs.entry_tc); freplace_prog = freplace_skel->progs.entry_freplace; - err = bpf_program__set_attach_target(freplace_prog, prog_fd, "subprog"); + err = bpf_program__set_attach_target(freplace_prog, prog_fd, + "subprog_tailcall_tc"); if (!ASSERT_OK(err, "set_attach_target")) goto out; @@ -1534,7 +1535,7 @@ static void test_tailcall_freplace(void) goto out; freplace_link = bpf_program__attach_freplace(freplace_prog, prog_fd, - "subprog"); + "subprog_tailcall_tc"); if (!ASSERT_OK_PTR(freplace_link, "attach_freplace")) goto out; @@ -1556,6 +1557,98 @@ static void test_tailcall_freplace(void) tailcall_freplace__destroy(freplace_skel); } +/* test_tailcall_bpf2bpf_freplace checks the failure that fails to attach a tail + * callee prog with freplace prog or fails to update an extended prog to + * prog_array map. + */ +static void test_tailcall_bpf2bpf_freplace(void) +{ + struct tailcall_freplace *freplace_skel = NULL; + struct bpf_link *freplace_link = NULL; + struct tc_bpf2bpf *tc_skel = NULL; + char buff[128] = {}; + int prog_fd, map_fd; + int err, key; + + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = buff, + .data_size_in = sizeof(buff), + .repeat = 1, + ); + + tc_skel = tc_bpf2bpf__open_and_load(); + if (!ASSERT_OK_PTR(tc_skel, "tc_bpf2bpf__open_and_load")) + goto out; + + prog_fd = bpf_program__fd(tc_skel->progs.entry_tc); + freplace_skel = tailcall_freplace__open(); + if (!ASSERT_OK_PTR(freplace_skel, "tailcall_freplace__open")) + goto out; + + err = bpf_program__set_attach_target(freplace_skel->progs.entry_freplace, + prog_fd, "subprog_tc"); + if (!ASSERT_OK(err, "set_attach_target")) + goto out; + + err = tailcall_freplace__load(freplace_skel); + if (!ASSERT_OK(err, "tailcall_freplace__load")) + goto out; + + /* OK to attach then detach freplace prog. */ + + freplace_link = bpf_program__attach_freplace(freplace_skel->progs.entry_freplace, + prog_fd, "subprog_tc"); + if (!ASSERT_OK_PTR(freplace_link, "attach_freplace")) + goto out; + + err = bpf_link__destroy(freplace_link); + if (!ASSERT_OK(err, "destroy link")) + goto out; + + /* OK to update prog_array map then delete element from the map. */ + + key = 0; + map_fd = bpf_map__fd(freplace_skel->maps.jmp_table); + err = bpf_map_update_elem(map_fd, &key, &prog_fd, BPF_ANY); + if (!ASSERT_OK(err, "update jmp_table")) + goto out; + + err = bpf_map_delete_elem(map_fd, &key); + if (!ASSERT_OK(err, "delete_elem from jmp_table")) + goto out; + + /* Fail to attach a tail callee prog with freplace prog. */ + + err = bpf_map_update_elem(map_fd, &key, &prog_fd, BPF_ANY); + if (!ASSERT_OK(err, "update jmp_table")) + goto out; + + freplace_link = bpf_program__attach_freplace(freplace_skel->progs.entry_freplace, + prog_fd, "subprog_tc"); + if (!ASSERT_ERR_PTR(freplace_link, "attach_freplace failure")) + goto out; + + err = bpf_map_delete_elem(map_fd, &key); + if (!ASSERT_OK(err, "delete_elem from jmp_table")) + goto out; + + /* Fail to update an extended prog to prog_array map. */ + + freplace_link = bpf_program__attach_freplace(freplace_skel->progs.entry_freplace, + prog_fd, "subprog_tc"); + if (!ASSERT_OK_PTR(freplace_link, "attach_freplace")) + goto out; + + err = bpf_map_update_elem(map_fd, &key, &prog_fd, BPF_ANY); + if (!ASSERT_ERR(err, "update jmp_table failure")) + goto out; + +out: + bpf_link__destroy(freplace_link); + tailcall_freplace__destroy(freplace_skel); + tc_bpf2bpf__destroy(tc_skel); +} + void test_tailcalls(void) { if (test__start_subtest("tailcall_1")) @@ -1606,4 +1699,6 @@ void test_tailcalls(void) test_tailcall_bpf2bpf_hierarchy_3(); if (test__start_subtest("tailcall_freplace")) test_tailcall_freplace(); + if (test__start_subtest("tailcall_bpf2bpf_freplace")) + test_tailcall_bpf2bpf_freplace(); } diff --git a/tools/testing/selftests/bpf/progs/tc_bpf2bpf.c b/tools/testing/selftests/bpf/progs/tc_bpf2bpf.c index 8a0632c37839a..34f3c780194e4 100644 --- a/tools/testing/selftests/bpf/progs/tc_bpf2bpf.c +++ b/tools/testing/selftests/bpf/progs/tc_bpf2bpf.c @@ -4,11 +4,30 @@ #include #include "bpf_misc.h" +struct { + __uint(type, BPF_MAP_TYPE_PROG_ARRAY); + __uint(max_entries, 1); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(__u32)); +} jmp_table SEC(".maps"); + +__noinline +int subprog_tailcall_tc(struct __sk_buff *skb) +{ + int ret = 1; + + bpf_tail_call_static(skb, &jmp_table, 0); + __sink(skb); + __sink(ret); + return ret; +} + __noinline -int subprog(struct __sk_buff *skb) +int subprog_tc(struct __sk_buff *skb) { int ret = 1; + __sink(skb); __sink(ret); return ret; } @@ -16,7 +35,8 @@ int subprog(struct __sk_buff *skb) SEC("tc") int entry_tc(struct __sk_buff *skb) { - return subprog(skb); + subprog_tc(skb); + return subprog_tailcall_tc(skb); } char __license[] SEC("license") = "GPL";