From mboxrd@z Thu Jan 1 00:00:00 1970 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=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 E446BC433E5 for ; Tue, 30 Mar 2021 12:06:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D4180619AD for ; Tue, 30 Mar 2021 12:06:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231966AbhC3MGT (ORCPT ); Tue, 30 Mar 2021 08:06:19 -0400 Received: from mga12.intel.com ([192.55.52.136]:33814 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232079AbhC3MF5 (ORCPT ); Tue, 30 Mar 2021 08:05:57 -0400 IronPort-SDR: azjuDTBTJnhpieVsYPP0nylJZ3DlYz8pVGOFLvVvS1h7pFF3hPyA2MqzZWvkJRs/u+F0N5OB0f b7kSWawD/80w== X-IronPort-AV: E=McAfee;i="6000,8403,9939"; a="171158236" X-IronPort-AV: E=Sophos;i="5.81,290,1610438400"; d="scan'208";a="171158236" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Mar 2021 05:05:57 -0700 IronPort-SDR: bQsUHzDGDLCDSUSHCWL++pPKdC0PCD8jzRAiKSvgN/05EJKLQtDQCCbr4WD/6KREWW9trv/qxa DjoL986L8fLw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.81,290,1610438400"; d="scan'208";a="418145849" Received: from silpixa00399839.ir.intel.com (HELO localhost.localdomain) ([10.237.222.142]) by orsmga008.jf.intel.com with ESMTP; 30 Mar 2021 05:05:55 -0700 From: Ciara Loftus To: netdev@vger.kernel.org, bpf@vger.kernel.org, magnus.karlsson@intel.com, bjorn@kernel.org, alexei.starovoitov@gmail.com Cc: Ciara Loftus Subject: [PATCH v3 bpf 2/3] libbpf: restore umem state after socket create failure Date: Tue, 30 Mar 2021 11:34:18 +0000 Message-Id: <20210330113419.4616-3-ciara.loftus@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210330113419.4616-1-ciara.loftus@intel.com> References: <20210330113419.4616-1-ciara.loftus@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org If the call to xsk_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 fails by: 1. ensuring the umem _save pointers are unmodified. 2. not unmapping the set of umem rings that were set up with the umem during xsk_umem__create, since those maps existed before the call to xsk_socket__create and should remain in tact even in the event of failure. Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices") Signed-off-by: Ciara Loftus --- tools/lib/bpf/xsk.c | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-) diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index 443b0cfb45e8..d4991ddff05a 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); @@ -797,8 +799,6 @@ static struct xsk_ctx *xsk_create_ctx(struct xsk_socket *xsk, memcpy(ctx->ifname, ifname, IFNAMSIZ - 1); ctx->ifname[IFNAMSIZ - 1] = '\0'; - umem->fill_save = NULL; - umem->comp_save = NULL; ctx->fill = fill; ctx->comp = comp; list_add(&ctx->list, &umem->ctx_list); @@ -854,6 +854,7 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr, struct xsk_socket *xsk; struct xsk_ctx *ctx; int err, ifindex; + bool unmap = umem->fill_save != fill; if (!umem || !xsk_ptr || !(rx || tx)) return -EFAULT; @@ -994,6 +995,8 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr, } *xsk_ptr = xsk; + umem->fill_save = NULL; + umem->comp_save = NULL; return 0; out_mmap_tx: @@ -1005,7 +1008,7 @@ 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); + xsk_put_ctx(ctx, unmap); out_socket: if (--umem->refcount) close(xsk->fd); @@ -1071,7 +1074,7 @@ 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 -- 2.17.1