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 620B225D20D for ; Tue, 24 Jun 2025 23:33:41 +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=1750808021; cv=none; b=eN4XFJ0f9uvvH6Xl4Sy66B2jh8z4Iz6bQSbo9aU0p+nL5qAD7DR/v1Y4g8bGQBhtveE167jp3VcZrkmk9j+Qdfd7JssqBhsY9a5bOgCp2ky54zPwvLbYDRSqiwWBczHzXk0/c6BU6KqiOXOpnu1YNheWoZCxI1q5H0hyR2+DCV0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750808021; c=relaxed/simple; bh=wiyXjFCr0vzH3k0goxeMxAlFdoQ0auzW5PJZxNpJEIU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=njvDnA2EfqUVtu5VnoorSpp+L0Y6P5lbrnpLJAAQel2WvVnsCcrwEzZvAEN1otLHXKhyDZKQ9d5ezng2MCgFLNaSLTMw7/qNMYT/QauKPbQZ+nI4F5Y3sKAz1D2LkN9wZ4nbdTSLV/LM27sLiIYKfx+PaxqhIUgY/gLycPben40= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WMS2nKvX; 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="WMS2nKvX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F060C4CEE3; Tue, 24 Jun 2025 23:33:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750808020; bh=wiyXjFCr0vzH3k0goxeMxAlFdoQ0auzW5PJZxNpJEIU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WMS2nKvXwIyZ7V/iuM6NVXj9OO5GMyuZfXl8pl/J/scOH/5HntlbWjhU7d0CVI5sK +pEmKNSRN5fLZExPIeGeG53ACFtWFNJr3jXJR89QqA6qWvGeyRF5STfHoet66v6uM6 MqXS7LAi06ZSv3+lCRVhpSMeeuyYLZEJlvnwv5PCzMHxjxcmdkfd5Ae9oOmoI0fGfW B58N+OGxUh/0AzWGy0oMCGxeR6HKUcxemnOVNacisnCYFyBFB/pxGEIHfsSiHapoBM SswZ/biLG5n8AqjjDaFquR5YyNjgHM0aBoeYcWqbDQlNpcaOqB62nJ0WHrXy+LfGoh yZcwBr2mvDaRw== 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 v3 bpf-next 2/2] selftests/bpf: Add tests for BPF_NEG range tracking logic Date: Tue, 24 Jun 2025 16:33:28 -0700 Message-ID: <20250624233328.313573-3-song@kernel.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250624233328.313573-1-song@kernel.org> References: <20250624233328.313573-1-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