From patchwork Wed Mar 24 14:13:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Loftus, Ciara" X-Patchwork-Id: 408654 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 9AC75C433E8 for ; Wed, 24 Mar 2021 14:45:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F97561A10 for ; Wed, 24 Mar 2021 14:45:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236218AbhCXOpR (ORCPT ); Wed, 24 Mar 2021 10:45:17 -0400 Received: from mga02.intel.com ([134.134.136.20]:2051 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236208AbhCXOo5 (ORCPT ); Wed, 24 Mar 2021 10:44:57 -0400 IronPort-SDR: NGZ8b6m8Q9OA8JFmyrkUxetg/JQJyM5xEfT2JokGph4qElL02fFJSyqgW3C7VV08LHbbX0qtxt pW7FUq7Ibk/g== X-IronPort-AV: E=McAfee;i="6000,8403,9933"; a="177834554" X-IronPort-AV: E=Sophos;i="5.81,274,1610438400"; d="scan'208";a="177834554" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Mar 2021 07:44:56 -0700 IronPort-SDR: 3Z5WjdL4vSeW6Dw8S/TO/2sIu+kCzedqmN08Vrkhn9ak9YkP2mUTxWpGvn6dcHGHvhxHJn1XpM h6oYyrz4zHsA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.81,274,1610438400"; d="scan'208";a="608127981" Received: from silpixa00399839.ir.intel.com (HELO localhost.localdomain) ([10.237.222.142]) by fmsmga005.fm.intel.com with ESMTP; 24 Mar 2021 07:44:55 -0700 From: Ciara Loftus To: netdev@vger.kernel.org, bpf@vger.kernel.org, magnus.karlsson@intel.com, bjorn@kernel.org Cc: Ciara Loftus Subject: [PATCH bpf 2/3] libbpf: restore umem state after socket create failure Date: Wed, 24 Mar 2021 14:13:36 +0000 Message-Id: <20210324141337.29269-3-ciara.loftus@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210324141337.29269-1-ciara.loftus@intel.com> References: <20210324141337.29269-1-ciara.loftus@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org If the call to socket_create fails, the user may want to retry the socket creation using the same umem. Ensure that the umem is in the same state on exit if the call failed by restoring the _save pointers and not unmapping the set of umem rings if those pointers are non NULL. Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices") Signed-off-by: Ciara Loftus --- tools/lib/bpf/xsk.c | 29 ++++++++++++++++++----------- 1 file changed, 18 insertions(+), 11 deletions(-) diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index 443b0cfb45e8..ec3c23299329 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -743,21 +743,23 @@ static struct xsk_ctx *xsk_get_ctx(struct xsk_umem *umem, int ifindex, return NULL; } -static void xsk_put_ctx(struct xsk_ctx *ctx) +static void xsk_put_ctx(struct xsk_ctx *ctx, bool unmap) { struct xsk_umem *umem = ctx->umem; struct xdp_mmap_offsets off; int err; if (--ctx->refcount == 0) { - err = xsk_get_mmap_offsets(umem->fd, &off); - if (!err) { - munmap(ctx->fill->ring - off.fr.desc, - off.fr.desc + umem->config.fill_size * - sizeof(__u64)); - munmap(ctx->comp->ring - off.cr.desc, - off.cr.desc + umem->config.comp_size * - sizeof(__u64)); + if (unmap) { + err = xsk_get_mmap_offsets(umem->fd, &off); + if (!err) { + munmap(ctx->fill->ring - off.fr.desc, + off.fr.desc + umem->config.fill_size * + sizeof(__u64)); + munmap(ctx->comp->ring - off.cr.desc, + off.cr.desc + umem->config.comp_size * + sizeof(__u64)); + } } list_del(&ctx->list); @@ -854,6 +856,9 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr, struct xsk_socket *xsk; struct xsk_ctx *ctx; int err, ifindex; + struct xsk_ring_prod *fsave = umem->fill_save; + struct xsk_ring_cons *csave = umem->comp_save; + bool unmap = !fsave; if (!umem || !xsk_ptr || !(rx || tx)) return -EFAULT; @@ -1005,7 +1010,9 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr, munmap(rx_map, off.rx.desc + xsk->config.rx_size * sizeof(struct xdp_desc)); out_put_ctx: - xsk_put_ctx(ctx); + umem->fill_save = fsave; + umem->comp_save = csave; + xsk_put_ctx(ctx, unmap); out_socket: if (--umem->refcount) close(xsk->fd); @@ -1071,7 +1078,7 @@ void xsk_socket__delete(struct xsk_socket *xsk) } } - xsk_put_ctx(ctx); + xsk_put_ctx(ctx, true); umem->refcount--; /* Do not close an fd that also has an associated umem connected