From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36D12DD for ; Tue, 21 Nov 2023 17:21:47 -0800 (PST) Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3AM0FFro017824 for ; Tue, 21 Nov 2023 17:21:47 -0800 Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3uh6xbrckj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 21 Nov 2023 17:21:46 -0800 Received: from twshared34392.14.frc2.facebook.com (2620:10d:c0a8:1c::1b) by mail.thefacebook.com (2620:10d:c0a8:83::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.34; Tue, 21 Nov 2023 17:19:30 -0800 Received: by devbig019.vll3.facebook.com (Postfix, from userid 137359) id F06713BE88955; Tue, 21 Nov 2023 17:17:17 -0800 (PST) From: Andrii Nakryiko To: , , , CC: , Subject: [PATCH bpf-next 09/10] selftests/bpf: validate async callback return value check correctness Date: Tue, 21 Nov 2023 17:16:55 -0800 Message-ID: <20231122011656.1105943-10-andrii@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231122011656.1105943-1-andrii@kernel.org> References: <20231122011656.1105943-1-andrii@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: Oygp_bgxP85kQiaTw_Fz6U7YX4vLSK3S X-Proofpoint-ORIG-GUID: Oygp_bgxP85kQiaTw_Fz6U7YX4vLSK3S X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.987,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-11-21_16,2023-11-21_01,2023-05-22_02 Adjust timer/timer_ret_1 test to validate more carefully verifier logic of enforcing async callback return value. This test will pass only if return result is marked precise and read. Signed-off-by: Andrii Nakryiko --- .../selftests/bpf/progs/timer_failure.c | 29 ++++++++++++++----- 1 file changed, 22 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/timer_failure.c b/tools/te= sting/selftests/bpf/progs/timer_failure.c index 9000da1e2120..a8dab6697810 100644 --- a/tools/testing/selftests/bpf/progs/timer_failure.c +++ b/tools/testing/selftests/bpf/progs/timer_failure.c @@ -21,17 +21,32 @@ struct { __type(value, struct elem); } timer_map SEC(".maps"); =20 -static int timer_cb_ret1(void *map, int *key, struct bpf_timer *timer) +__naked __noinline __used +static unsigned long timer_cb_ret_bad() { - if (bpf_get_smp_processor_id() % 2) - return 1; - else - return 0; + asm volatile ( + "call %[bpf_get_prandom_u32];" + "if r0 > 1000 goto 1f;" + "r0 =3D 0;" + "1:" + "goto +0;" /* checkpoint */ + /* async callback is expected to return 0, so branch above + * skipping r0 =3D 0; should lead to a failure, but if exit + * instruction doesn't enforce r0's precision, this callback + * will be successfully verified + */ + "exit;" + : + : __imm(bpf_get_prandom_u32) + : __clobber_common + ); } =20 SEC("fentry/bpf_fentry_test1") __failure __msg("should have been in [0, 0]") -int BPF_PROG2(test_ret_1, int, a) +__log_level(2) +__flag(BPF_F_TEST_STATE_FREQ) +int BPF_PROG2(test_bad_ret, int, a) { int key =3D 0; struct bpf_timer *timer; @@ -39,7 +54,7 @@ int BPF_PROG2(test_ret_1, int, a) timer =3D bpf_map_lookup_elem(&timer_map, &key); if (timer) { bpf_timer_init(timer, &timer_map, CLOCK_BOOTTIME); - bpf_timer_set_callback(timer, timer_cb_ret1); + bpf_timer_set_callback(timer, timer_cb_ret_bad); bpf_timer_start(timer, 1000, 0); } =20 --=20 2.34.1