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=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 09F70C433E1 for ; Tue, 11 Aug 2020 08:45:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DDF3D2078E for ; Tue, 11 Aug 2020 08:45:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597135549; bh=CM0r4ny8D0CnW7Az/Is/5+LTSrdxUCBXSOMBqQBAgGs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=znUfpXlLfZX2+It9UQlfAD/NfxjSPsdqGF7Y/S4z0LqyR/qBBimu1BtXuj/YGjauD C/O5GKYBj960SId4C5Z+Q4iKPkFJB7tnd7/msaGKQ85G4MgRjmlxFlmpbGTtlDBv51 2VNFwy84R9eu374s9n4wNMhkXjk72nqDXsE0QHVI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728325AbgHKIpt (ORCPT ); Tue, 11 Aug 2020 04:45:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:57854 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728224AbgHKIpt (ORCPT ); Tue, 11 Aug 2020 04:45:49 -0400 Received: from localhost (unknown [213.57.247.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 69972206B2; Tue, 11 Aug 2020 08:45:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597135548; bh=CM0r4ny8D0CnW7Az/Is/5+LTSrdxUCBXSOMBqQBAgGs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ht3PbJ5XpCZCSYzCCFNfDFkYpyjh3FEFVjpBwFIdICQtIL8FaafJXyIVUp4oEsxKE lqFIT0Zcqt+mNiHrB5lrFCBy85yHbajpnb5ghSQF8YuvaIYxpIhJ+VqQ0yPKBVFo8t JQK234l5Ky3uJrRNrvtgv5F9IRkFkSfa/jc5bVDY= Date: Tue, 11 Aug 2020 11:45:44 +0300 From: Leon Romanovsky To: Md Haris Iqbal Cc: danil.kipnis@cloud.ionos.com, jinpu.wang@cloud.ionos.com, linux-rdma@vger.kernel.org, dledford@redhat.com, jgg@ziepe.ca, linux-block@vger.kernel.org, kernel test robot Subject: Re: [PATCH v2] RDMA/rtrs-srv: Incorporate ib_register_client into rtrs server init Message-ID: <20200811084544.GB634816@unreal> References: <20200810115049.304118-1-haris.iqbal@cloud.ionos.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200810115049.304118-1-haris.iqbal@cloud.ionos.com> Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Mon, Aug 10, 2020 at 05:20:49PM +0530, Md Haris Iqbal wrote: > The rnbd_server module's communication manager (cm) initialization depends > on the registration of the "network namespace subsystem" of the RDMA CM > agent module. As such, when the kernel is configured to load the > rnbd_server and the RDMA cma module during initialization; and if the > rnbd_server module is initialized before RDMA cma module, a null ptr > dereference occurs during the RDMA bind operation. > > Call trace below, > > [ 1.904782] Call Trace: > [ 1.904782] ? xas_load+0xd/0x80 > [ 1.904782] xa_load+0x47/0x80 > [ 1.904782] cma_ps_find+0x44/0x70 > [ 1.904782] rdma_bind_addr+0x782/0x8b0 > [ 1.904782] ? get_random_bytes+0x35/0x40 > [ 1.904782] rtrs_srv_cm_init+0x50/0x80 > [ 1.904782] rtrs_srv_open+0x102/0x180 > [ 1.904782] ? rnbd_client_init+0x6e/0x6e > [ 1.904782] rnbd_srv_init_module+0x34/0x84 > [ 1.904782] ? rnbd_client_init+0x6e/0x6e > [ 1.904782] do_one_initcall+0x4a/0x200 > [ 1.904782] kernel_init_freeable+0x1f1/0x26e > [ 1.904782] ? rest_init+0xb0/0xb0 > [ 1.904782] kernel_init+0xe/0x100 > [ 1.904782] ret_from_fork+0x22/0x30 > [ 1.904782] Modules linked in: > [ 1.904782] CR2: 0000000000000015 > [ 1.904782] ---[ end trace c42df88d6c7b0a48 ]--- > > All this happens cause the cm init is in the call chain of the module init, > which is not a preferred practice. > > So remove the call to rdma_create_id() from the module init call chain. > Instead register rtrs-srv as an ib client, which makes sure that the > rdma_create_id() is called only when an ib device is added. > > Fixes: 9cb837480424 ("RDMA/rtrs: server: main functionality") > Reported-by: kernel test robot > Signed-off-by: Md Haris Iqbal > --- > Change in v2: > Use only single variable to track number of IB devices and failure > Change according to kernel coding style > > drivers/infiniband/ulp/rtrs/rtrs-srv.c | 79 +++++++++++++++++++++++++- > drivers/infiniband/ulp/rtrs/rtrs-srv.h | 6 ++ > 2 files changed, 82 insertions(+), 3 deletions(-) > > diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv.c b/drivers/infiniband/ulp/rtrs/rtrs-srv.c > index 0d9241f5d9e6..69a37ce73b0c 100644 > --- a/drivers/infiniband/ulp/rtrs/rtrs-srv.c > +++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.c > @@ -16,6 +16,7 @@ > #include "rtrs-srv.h" > #include "rtrs-log.h" > #include > +#include > > MODULE_DESCRIPTION("RDMA Transport Server"); > MODULE_LICENSE("GPL"); > @@ -31,6 +32,7 @@ MODULE_LICENSE("GPL"); > static struct rtrs_rdma_dev_pd dev_pd; > static mempool_t *chunk_pool; > struct class *rtrs_dev_class; > +static struct rtrs_srv_ib_ctx ib_ctx; > > static int __read_mostly max_chunk_size = DEFAULT_MAX_CHUNK_SIZE; > static int __read_mostly sess_queue_depth = DEFAULT_SESS_QUEUE_DEPTH; > @@ -2033,6 +2035,64 @@ static void free_srv_ctx(struct rtrs_srv_ctx *ctx) > kfree(ctx); > } > > +static int rtrs_srv_add_one(struct ib_device *device) > +{ > + struct rtrs_srv_ctx *ctx; > + int ret; > + > + if (ib_ctx.ib_dev_count) > + goto out; > + > + /* > + * Since our CM IDs are NOT bound to any ib device we will create them > + * only once > + */ > + ctx = ib_ctx.srv_ctx; > + ret = rtrs_srv_rdma_init(ctx, ib_ctx.port); > + if (ret) { > + /* > + * We errored out here. > + * According to the ib code, if we encounter an error here then the > + * error code is ignored, and no more calls to our ops are made. > + */ > + pr_err("Failed to initialize RDMA connection"); > + ib_ctx.ib_dev_count = -1; > + return ret; > + } > + > +out: > + /* > + * Keep a track on the number of ib devices added > + */ > + ib_ctx.ib_dev_count++; > + > + return 0; > +} > + > +static void rtrs_srv_remove_one(struct ib_device *device, void *client_data) > +{ > + struct rtrs_srv_ctx *ctx; > + > + ib_ctx.ib_dev_count--; > + > + if (ib_ctx.ib_dev_count) > + return; > + > + /* > + * Since our CM IDs are NOT bound to any ib device we will remove them > + * only once, when the last device is removed > + */ > + ctx = ib_ctx.srv_ctx; > + rdma_destroy_id(ctx->cm_id_ip); > + rdma_destroy_id(ctx->cm_id_ib); > +} > + > +static struct ib_client rtrs_srv_client = { > + .name = "rtrs_server", > + .add = rtrs_srv_add_one, > + .remove = rtrs_srv_remove_one > +}; > + > /** > * rtrs_srv_open() - open RTRS server context > * @ops: callback functions > @@ -2051,12 +2111,26 @@ struct rtrs_srv_ctx *rtrs_srv_open(struct rtrs_srv_ops *ops, u16 port) > if (!ctx) > return ERR_PTR(-ENOMEM); > > - err = rtrs_srv_rdma_init(ctx, port); > + ib_ctx = (struct rtrs_srv_ib_ctx) { > + .srv_ctx = ctx, > + .port = port, > + }; > + > + err = ib_register_client(&rtrs_srv_client); > if (err) { > free_srv_ctx(ctx); > return ERR_PTR(err); > } > > + /* > + * Since ib_register_client does not propagate the device add error > + * we check if .add was called and the RDMA connection init failed > + */ > + if (ib_ctx.ib_dev_count < 0) { > + free_srv_ctx(ctx); > + return ERR_PTR(-ENODEV); > + } I afraid that you overcomplicated here, ib_register_client() doesn't return error if ->add() for specific device failed, it doesn't mean that ->add won't be called again for another device. So you don't need to use ib_dev_count == -1, just keep it to be 0 and leave to rtrs_srv_close() to free srv_ctx. Failure to call ->add shouldn't be any different from no-ib-devices situation. Thanks > + > return ctx; > } > EXPORT_SYMBOL(rtrs_srv_open); > @@ -2090,8 +2164,7 @@ static void close_ctx(struct rtrs_srv_ctx *ctx) > */ > void rtrs_srv_close(struct rtrs_srv_ctx *ctx) > { > - rdma_destroy_id(ctx->cm_id_ip); > - rdma_destroy_id(ctx->cm_id_ib); > + ib_unregister_client(&rtrs_srv_client); > close_ctx(ctx); > free_srv_ctx(ctx); > } > diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv.h b/drivers/infiniband/ulp/rtrs/rtrs-srv.h > index dc95b0932f0d..e8f7e99a9a6e 100644 > --- a/drivers/infiniband/ulp/rtrs/rtrs-srv.h > +++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.h > @@ -118,6 +118,12 @@ struct rtrs_srv_ctx { > struct list_head srv_list; > }; > > +struct rtrs_srv_ib_ctx { > + struct rtrs_srv_ctx *srv_ctx; > + u16 port; > + int ib_dev_count; > +}; > + > extern struct class *rtrs_dev_class; > > void close_sess(struct rtrs_srv_sess *sess); > -- > 2.25.1 >