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=-15.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 B085AC636CA for ; Fri, 16 Jul 2021 15:22:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 93A73613F5 for ; Fri, 16 Jul 2021 15:22:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240679AbhGPPY7 (ORCPT ); Fri, 16 Jul 2021 11:24:59 -0400 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:40739 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233094AbhGPPY6 (ORCPT ); Fri, 16 Jul 2021 11:24:58 -0400 Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id AF5065C010C; Fri, 16 Jul 2021 11:22:03 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute1.internal (MEProxy); Fri, 16 Jul 2021 11:22:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm3; bh=EnQnVNaYAbWAfONTqxilzZm3cLax0YiVucCGLrJIZ Mc=; b=hDfLTRNiLOY7tdaJjyUBsOjWyZ0gLCj+CkDnMhLeX+eayijdde/4L5CDA qgb8XMH2Od8RRhQ0opCAVj8qJOzYjzzUybvP6MTyYHBvTZRWp/soAYnOhWW7PAtM x+3BUB6kcq9AjqfpKNGxB8EKO3OX+ifVi1l/uA5AXfJRkZHKWd4LKQD3RCYGWFh+ 9bNiPC14YFzj73Smno3NianbqUQVYVAhwMKCUMNETKO0ddzXuahLMTH6DUqVrx/M XGJW+rD7V3z/xxdOdS56+s/0LgqiLYU+r0D5I72H7V5N62gZXfIvcYz7eKNBpMuX Dr38x1/UNguGTswLy+NRCvd68PdbA== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvtddrvdefgdekhecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefuvfhfhffkffgfgggjtgfgsehtjeertddtfeejnecuhfhrohhmpeforghrthih nhgrshcurfhumhhpuhhtihhsuceomheslhgrmhgsuggrrdhltheqnecuggftrfgrthhtvg hrnheptdffkeelgeegheduieeiffefudefgfduuefhjefftddtteehveeludduteduffdv necuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepmheslh grmhgsuggrrdhlth X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 16 Jul 2021 11:22:01 -0400 (EDT) Subject: Re: [PATCH bpf 1/2] libbpf: fix removal of inner map in bpf_object__create_map To: Andrii Nakryiko Cc: bpf , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko References: <20210714165440.472566-1-m@lambda.lt> <20210714165440.472566-2-m@lambda.lt> From: Martynas Pumputis Message-ID: Date: Fri, 16 Jul 2021 17:24:14 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 7/16/21 7:27 AM, Andrii Nakryiko wrote: > On Wed, Jul 14, 2021 at 9:52 AM Martynas Pumputis wrote: >> >> If creating an outer map of a BTF-defined map-in-map fails (via >> bpf_object__create_map()), then the previously created its inner map >> won't be destroyed. >> >> Fix this by ensuring that the destroy routines are not bypassed in the >> case of a failure. >> >> Fixes: 646f02ffdd49c ("libbpf: Add BTF-defined map-in-map support") >> Reported-by: Andrii Nakryiko >> Signed-off-by: Martynas Pumputis >> --- >> tools/lib/bpf/libbpf.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c >> index 6f5e2757bb3c..1a840e81ea0a 100644 >> --- a/tools/lib/bpf/libbpf.c >> +++ b/tools/lib/bpf/libbpf.c >> @@ -4479,6 +4479,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b >> { >> struct bpf_create_map_attr create_attr; >> struct bpf_map_def *def = &map->def; >> + int ret = 0; >> >> memset(&create_attr, 0, sizeof(create_attr)); >> >> @@ -4561,7 +4562,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b >> } >> >> if (map->fd < 0) >> - return -errno; >> + ret = -errno; > > Oh, isn't this a complicated function, eh? I stared at the code for a > while until I understood the whole idea with map->inner_map handling > there. > > I think your change is correct, I'd just love you to consolidate all > those "int err" definitions, and use just one throughout this > function. It will clean up two other if() blocks, and in this case > "err" name is more appropriate, because it always is <= 0. Good idea. I will send v2 once we have agreed on the selftesting issue. > >> >> if (bpf_map_type__is_map_in_map(def->type) && map->inner_map) { >> if (obj->gen_loader) >> @@ -4570,7 +4571,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b >> zfree(&map->inner_map); >> } >> >> - return 0; >> + return ret; >> } >> >> static int init_map_slots(struct bpf_object *obj, struct bpf_map *map) >> -- >> 2.32.0 >>