From patchwork Thu Sep 14 23:11:14 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Kelly X-Patchwork-Id: 13386189 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 29ABDD50B for ; Thu, 14 Sep 2023 23:12:35 +0000 (UTC) Received: from mx0b-00206402.pphosted.com (mx0b-00206402.pphosted.com [148.163.152.16]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 99ECF2711 for ; Thu, 14 Sep 2023 16:12:34 -0700 (PDT) Received: from pps.filterd (m0354653.ppops.net [127.0.0.1]) by mx0b-00206402.pphosted.com (8.17.1.22/8.17.1.22) with ESMTP id 38EL8YFb001185; Thu, 14 Sep 2023 23:12:16 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=crowdstrike.com; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding:content-type; s=default; bh=weyxGZ+zIAZpTxNjkrw+h0hb9W7VWwg5fe+e8YDoqeo=; b=nxY78WPqGabZ B835BAoYTgMt4DhyzKesKlum64HTSZkwQQHRV+eOrbVscwN49TgLQvvMqDmY+WjG QR/e9KAOba8WCb2XA81i0+ju0B5+zu3M0TBJny109+YojD+kFCuhJSYPPhI3vs+D fdiBWkBTVPuKYPZ1GGfvGSRRYcCMQpsihwsDgPnrhYsvS5gxBsIBS45zW5vwdfvL 7SqYh3rPFnSsV12deK+JnctD9xgLszhBoBpfMYAxymQG0iRsVv2CzntUuRQ52A/r F4qxGjcVY8eRA5FSEkbObGF/5k1/fphAQHlEjXHc8h2F/LFlK+Vc0xCmQNbwc3Bl 3p5CUkb7Pw== Received: from 04wpexch06.crowdstrike.sys (dragosx.crowdstrike.com [208.42.231.60]) by mx0b-00206402.pphosted.com (PPS) with ESMTPS id 3t2y9fpcp7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 14 Sep 2023 23:12:16 +0000 (GMT) Received: from LL-556NGK3.crowdstrike.sys (10.100.11.122) by 04wpexch06.crowdstrike.sys (10.100.11.99) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.16; Thu, 14 Sep 2023 23:12:14 +0000 From: Martin Kelly To: CC: Andrii Nakryiko , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Martin Kelly Subject: [PATCH bpf-next 05/14] libbpf: add ring__producer_pos, ring__consumer_pos Date: Thu, 14 Sep 2023 16:11:14 -0700 Message-ID: <20230914231123.193901-6-martin.kelly@crowdstrike.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230914231123.193901-1-martin.kelly@crowdstrike.com> References: <20230914231123.193901-1-martin.kelly@crowdstrike.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Originating-IP: [10.100.11.122] X-ClientProxiedBy: 04WPEXCH12.crowdstrike.sys (10.100.11.116) To 04wpexch06.crowdstrike.sys (10.100.11.99) X-Disclaimer: USA X-Proofpoint-ORIG-GUID: sbBV6UewNuLk2BjQq2O4BY06yYWwd1y4 X-Proofpoint-GUID: sbBV6UewNuLk2BjQq2O4BY06yYWwd1y4 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.267,Aquarius:18.0.980,Hydra:6.0.601,FMLib:17.11.176.26 definitions=2023-09-14_12,2023-09-14_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 clxscore=1015 spamscore=0 phishscore=0 mlxscore=0 bulkscore=0 malwarescore=0 adultscore=0 impostorscore=0 suspectscore=0 lowpriorityscore=0 mlxlogscore=841 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2308100000 definitions=main-2309140202 X-Patchwork-Delegate: bpf@iogearbox.net Add APIs to get the producer and consumer position for a given ringbuffer. Signed-off-by: Martin Kelly --- tools/lib/bpf/libbpf.h | 16 ++++++++++++++++ tools/lib/bpf/libbpf.map | 2 ++ tools/lib/bpf/ringbuf.c | 14 ++++++++++++++ 3 files changed, 32 insertions(+) diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 2d6c39e20863..935162dbb3bf 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -1263,6 +1263,22 @@ LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb); LIBBPF_API struct ring *ring_buffer__ring(struct ring_buffer *rb, unsigned int idx); +/** + * @brief **ring__consumer_pos()** returns the current consumer position. + * + * @param r A ring object. + * @return The current consumer position. + */ +LIBBPF_API unsigned long ring__consumer_pos(const struct ring *r); + +/** + * @brief **ring__producer_pos()** returns the current producer position. + * + * @param r A ring object. + * @return The current producer position. + */ +LIBBPF_API unsigned long ring__producer_pos(const struct ring *r); + struct user_ring_buffer_opts { size_t sz; /* size of this struct, for forward/backward compatibility */ }; diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 7a7370c2bc25..1c532fe7a445 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -401,4 +401,6 @@ LIBBPF_1.3.0 { bpf_program__attach_tcx; bpf_program__attach_uprobe_multi; ring_buffer__ring; + ring__consumer_pos; + ring__producer_pos; } LIBBPF_1.2.0; diff --git a/tools/lib/bpf/ringbuf.c b/tools/lib/bpf/ringbuf.c index 2857df0f2d03..54c596db57a4 100644 --- a/tools/lib/bpf/ringbuf.c +++ b/tools/lib/bpf/ringbuf.c @@ -336,6 +336,20 @@ struct ring *ring_buffer__ring(struct ring_buffer *rb, unsigned int idx) return rb->rings[idx]; } +unsigned long ring__consumer_pos(const struct ring *r) +{ + /* Synchronizes with smp_store_release() in ringbuf_process_ring(). */ + return smp_load_acquire(r->consumer_pos); +} + +unsigned long ring__producer_pos(const struct ring *r) +{ + /* Synchronizes with smp_store_release() in __bpf_ringbuf_reserve() in + * the kernel. + */ + return smp_load_acquire(r->producer_pos); +} + static void user_ringbuf_unmap_ring(struct user_ring_buffer *rb) { if (rb->consumer_pos) {