From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B25792D4B41 for ; Wed, 25 Jun 2025 16:40:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750869641; cv=none; b=oK2skr5I/C2AukIxALWqgyZ/gPbjICGkOrBX5IT7yLbcGrOCZIj5xZeK0oorKnSnZja9hp4A1ZZbM7TOTDB0cYjM2w5QgD/KNeC2pD27yuZnFkWdfDc0W0IqGGXhMLiiAsBD+QbZz8yGPkE0OpO19oxWXb0oOc/jsXjenP8rRVA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750869641; c=relaxed/simple; bh=wiyXjFCr0vzH3k0goxeMxAlFdoQ0auzW5PJZxNpJEIU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SWshwc80ZlTZvzyNxAWbnmoxwNbDA03mxm64Y4KniCPH7oqFrjBOZP3au2zwIm5O6acNZ1NUauF/of9IndwaEGGxc6eLA5vaBy+l7mKSJFJL+kynwHzw2vM+LEzGNvALW/2Atd+4iZaS9wdhpKbp15HU4MaP/tvBNhGZxlaouro= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GffsQlb7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GffsQlb7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 258A6C4CEEA; Wed, 25 Jun 2025 16:40:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750869641; bh=wiyXjFCr0vzH3k0goxeMxAlFdoQ0auzW5PJZxNpJEIU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GffsQlb7DzLFP1nUIxwWcMyq/vd/t1Nrt9EcWWnzbVanW8Q0fZaFlp7pjp3z2DEE9 aHAflV2oMwbhzRCgc3leZUm0bIELCintKXKjJHC46LfE8yvKdAR9UIpA9HZEzX8NlD p77F4WXC9FzUhuSXiENfp37kcU0GbK4YdV0ED33CQcndxaBVRft1R0A+JD8GuQx8Xn GsEEz8Z5CtSF27wjfSkpGQQD4iM1AaMglO6MZh3HyeZZ5OewxZon0gDfNO0c7zSVLQ sR3omqO2/1WZZN8PBBQHH23dLhTX6M+tt+X06f+OSYSoFbKszJ+dGpRMn94ril+Ak1 3W88PY7/YNE8Q== From: Song Liu To: bpf@vger.kernel.org Cc: kernel-team@meta.com, andrii@kernel.org, eddyz87@gmail.com, ast@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, Song Liu Subject: [PATCH v4 bpf-next 2/2] selftests/bpf: Add tests for BPF_NEG range tracking logic Date: Wed, 25 Jun 2025 09:40:25 -0700 Message-ID: <20250625164025.3310203-3-song@kernel.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250625164025.3310203-1-song@kernel.org> References: <20250625164025.3310203-1-song@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit BPF_REG now has range tracking logic. Add selftests for BPF_NEG. Specifically, return value of LSM hook lsm.s/socket_connect is used to show that the verifer tracks BPF_NEG(1) falls in the [-4095, 0] range; while BPF_NEG(100000) does not fall in that range. Signed-off-by: Song Liu --- .../selftests/bpf/progs/verifier_precision.c | 70 +++++++++++++++++++ 1 file changed, 70 insertions(+) diff --git a/tools/testing/selftests/bpf/progs/verifier_precision.c b/tools/testing/selftests/bpf/progs/verifier_precision.c index 9fe5d255ee37..73fee2aec698 100644 --- a/tools/testing/selftests/bpf/progs/verifier_precision.c +++ b/tools/testing/selftests/bpf/progs/verifier_precision.c @@ -231,4 +231,74 @@ __naked void bpf_cond_op_not_r10(void) ::: __clobber_all); } +SEC("lsm.s/socket_connect") +__success __log_level(2) +__msg("0: (b7) r0 = 1 ; R0_w=1") +__msg("1: (84) w0 = -w0 ; R0_w=0xffffffff") +__msg("mark_precise: frame0: last_idx 2 first_idx 0 subseq_idx -1") +__msg("mark_precise: frame0: regs=r0 stack= before 1: (84) w0 = -w0") +__msg("mark_precise: frame0: regs=r0 stack= before 0: (b7) r0 = 1") +__naked int bpf_neg_2(void) +{ + /* + * lsm.s/socket_connect requires a return value within [-4095, 0]. + * Returning -1 is allowed + */ + asm volatile ( + "r0 = 1;" + "w0 = -w0;" + "exit;" + ::: __clobber_all); +} + +SEC("lsm.s/socket_connect") +__failure __msg("At program exit the register R0 has") +__naked int bpf_neg_3(void) +{ + /* + * lsm.s/socket_connect requires a return value within [-4095, 0]. + * Returning -10000 is not allowed. + */ + asm volatile ( + "r0 = 10000;" + "w0 = -w0;" + "exit;" + ::: __clobber_all); +} + +SEC("lsm.s/socket_connect") +__success __log_level(2) +__msg("0: (b7) r0 = 1 ; R0_w=1") +__msg("1: (87) r0 = -r0 ; R0_w=-1") +__msg("mark_precise: frame0: last_idx 2 first_idx 0 subseq_idx -1") +__msg("mark_precise: frame0: regs=r0 stack= before 1: (87) r0 = -r0") +__msg("mark_precise: frame0: regs=r0 stack= before 0: (b7) r0 = 1") +__naked int bpf_neg_4(void) +{ + /* + * lsm.s/socket_connect requires a return value within [-4095, 0]. + * Returning -1 is allowed + */ + asm volatile ( + "r0 = 1;" + "r0 = -r0;" + "exit;" + ::: __clobber_all); +} + +SEC("lsm.s/socket_connect") +__failure __msg("At program exit the register R0 has") +__naked int bpf_neg_5(void) +{ + /* + * lsm.s/socket_connect requires a return value within [-4095, 0]. + * Returning -10000 is not allowed. + */ + asm volatile ( + "r0 = 10000;" + "r0 = -r0;" + "exit;" + ::: __clobber_all); +} + char _license[] SEC("license") = "GPL"; -- 2.47.1