From patchwork Fri Apr 16 02:55:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Marchevsky X-Patchwork-Id: 12206551 X-Patchwork-Delegate: bpf@iogearbox.net 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 A4618C433ED for ; Fri, 16 Apr 2021 02:56:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B2BD610FB for ; Fri, 16 Apr 2021 02:56:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234903AbhDPC4g (ORCPT ); Thu, 15 Apr 2021 22:56:36 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:9284 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234751AbhDPC4g (ORCPT ); Thu, 15 Apr 2021 22:56:36 -0400 Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 13G2uCsY022654 for ; Thu, 15 Apr 2021 19:56:12 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=aLyr9rw7bFY9QZ+y3NJ9jMrUlHMAfR8/GWPj3dsBN2w=; b=WGpl1HiaQX21yuVQzvaF85Ng4Fpv4udilxabovKJ2kEwQlY9d/XPhtSpHuQPx5E6kqO2 uhzguay3Hf11cUzkf+T1sXJ7bSKegr2h4viz9Epf7Ll+XIhN201P4tTqVQEiAavy8KdQ 9rRj4Eo1hENFsNFs+bVycmYFtbIJanL9dJc= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 37xr303g18-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 15 Apr 2021 19:56:12 -0700 Received: from intmgw001.25.frc3.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:21d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Thu, 15 Apr 2021 19:56:11 -0700 Received: by devbig030.frc3.facebook.com (Postfix, from userid 158236) id 8E208A2A643; Thu, 15 Apr 2021 19:56:04 -0700 (PDT) From: Dave Marchevsky To: CC: , Alexei Starovoitov , Daniel Borkmann , Song Liu , Yonghong Song , Dave Marchevsky Subject: [PATCH bpf-next 1/3] bpf: refine retval for bpf_get_task_stack helper Date: Thu, 15 Apr 2021 19:55:35 -0700 Message-ID: <20210416025537.2352753-2-davemarchevsky@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210416025537.2352753-1-davemarchevsky@fb.com> References: <20210416025537.2352753-1-davemarchevsky@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: 8Rbn4b0YJrJM-L42Ln0MCMp-rx2YDNQf X-Proofpoint-GUID: 8Rbn4b0YJrJM-L42Ln0MCMp-rx2YDNQf X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.761 definitions=2021-04-15_11:2021-04-15,2021-04-15 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 suspectscore=0 lowpriorityscore=0 bulkscore=0 clxscore=1015 adultscore=0 priorityscore=1501 impostorscore=0 phishscore=0 mlxlogscore=999 mlxscore=0 malwarescore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104060000 definitions=main-2104160023 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Verifier can constrain the min/max bounds of bpf_get_task_stack's return value more tightly than the default tnum_unknown. Like bpf_get_stack, return value is num bytes written into a caller-supplied buf, or error, so do_refine_retval_range will work. Signed-off-by: Dave Marchevsky Acked-by: Song Liu --- kernel/bpf/verifier.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 852541a435ef..348e97f77003 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5767,6 +5767,7 @@ static void do_refine_retval_range(struct bpf_reg_state *regs, int ret_type, if (ret_type != RET_INTEGER || (func_id != BPF_FUNC_get_stack && + func_id != BPF_FUNC_get_task_stack && func_id != BPF_FUNC_probe_read_str && func_id != BPF_FUNC_probe_read_kernel_str && func_id != BPF_FUNC_probe_read_user_str))