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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E21DC4332F for ; Wed, 4 May 2022 11:20:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348692AbiEDLXd (ORCPT ); Wed, 4 May 2022 07:23:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235140AbiEDLXa (ORCPT ); Wed, 4 May 2022 07:23:30 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 9B5662A270 for ; Wed, 4 May 2022 04:19:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1651663194; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=lXMVJx+7jkqkO46ktvyPIT140OLmxQYNMIQN5pPJqZw=; b=SCYjalymi6XRXSaP1h/RlDovvtF9qAjCF0lzM0b5t9JasFluZbrZw9oO+oaKU2UHSbvPv2 LwDSf6GNhO8CXK9Joynrr5M17UPtkXWLzP+OU/yc1WDnvj8Uw0Xg2p1sIQ3pWCmtSMNqtq 0zhL7LZsKPdm5X1N2kzQbKD5q1RgqpQ= Received: from mail-ej1-f71.google.com (mail-ej1-f71.google.com [209.85.218.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-208-EFN7_W9jPNGba6QV2r9uAw-1; Wed, 04 May 2022 07:19:53 -0400 X-MC-Unique: EFN7_W9jPNGba6QV2r9uAw-1 Received: by mail-ej1-f71.google.com with SMTP id dt6-20020a170907728600b006f40b4ea280so647384ejc.21 for ; Wed, 04 May 2022 04:19:53 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=lXMVJx+7jkqkO46ktvyPIT140OLmxQYNMIQN5pPJqZw=; b=cy8O5FeCkgJ1bCmwsj7sk4pqbtb3OPYhd17BJBvWfzNIQxDxN2HF+Bfa0si/cYNEuq KzW5jLInCGLmK40Kv2pkZjiTimRbFPAS0hjka/+ndEbRRTRhv4oQKv4aiUHQ2F46GOLO uWn+d+R1yKEsyEI5/qq6izZ1tVOBVtpvKTN34ONuThvDJ4j1oZUk693DgKw4UyTm1T/q gu0pMZxp+KnOrz0Or1HxDhL4Q2rf9wYWbqg+SXPEMgVnfstjlGJJS8OMz5oNIQ8ZzXGa McTWUUrsBSTEBLOfZGurWTog2WJLZroT9sehspdKFxy9NLhz8BpEqGWRW4cRmHxPs2/c NtcQ== X-Gm-Message-State: AOAM5312lGHOFreOxFnCEIO8CNru4v1HT08GW9YJ37xxeqeeDJWO1ipI o7GA0dXxl2h1BEKFAuzCNLObAbHfz8u7FvkESwPDduHt977hEcZVs9zSnj+oAzzlgixtGrsO7xY FRejz88mKdYrqEqgZoArTy5Mh X-Received: by 2002:a17:907:a41f:b0:6f3:e75c:5a77 with SMTP id sg31-20020a170907a41f00b006f3e75c5a77mr18660112ejc.70.1651663192531; Wed, 04 May 2022 04:19:52 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzceBB2USpyoo+pVY8+rlawNZ6Is0gHrKs+ouHJgFVE+uPIf9IviOi2f9nkD4t0M0FD3BfvVg== X-Received: by 2002:a17:907:a41f:b0:6f3:e75c:5a77 with SMTP id sg31-20020a170907a41f00b006f3e75c5a77mr18660073ejc.70.1651663192175; Wed, 04 May 2022 04:19:52 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id l24-20020a056402029800b0042617ba63a7sm9104938edv.49.2022.05.04.04.19.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 May 2022 04:19:50 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 08C323464C2; Wed, 4 May 2022 13:19:50 +0200 (CEST) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Zhengchao Shao , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, kpsingh@kernel.org, bigeasy@linutronix.de, imagedong@tencent.com, petrm@nvidia.com, memxor@gmail.com, arnd@arndb.de, weiyongjun1@huawei.com, shaozhengchao@huawei.com, yuehaibing@huawei.com Subject: Re: [PATCH bpf-next] bpf/xdp: Can't detach BPF XDP prog if not exist In-Reply-To: <20220504035207.98221-1-shaozhengchao@huawei.com> References: <20220504035207.98221-1-shaozhengchao@huawei.com> X-Clacks-Overhead: GNU Terry Pratchett Date: Wed, 04 May 2022 13:19:49 +0200 Message-ID: <875ymlwnmy.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Zhengchao Shao writes: > if user sets nonexistent xdp_flags to detach xdp prog, kernel should > return err and tell user that detach failed with detail info. > > Signed-off-by: Zhengchao Shao I kinda see your point, but this will change user-visible behaviour that applications might be relying on, so I don't think we can make this change at this stage. Why can't your application just query the link for whether a program is attached? -Toke