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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 02C13C433B4 for ; Mon, 5 Apr 2021 14:16:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B28F36124B for ; Mon, 5 Apr 2021 14:16:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237444AbhDEOQH (ORCPT ); Mon, 5 Apr 2021 10:16:07 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:21597 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237330AbhDEOQG (ORCPT ); Mon, 5 Apr 2021 10:16:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617632159; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3odf2vfILdNMkO2s2+U+l93jP5VUsQZO+yjT8s2izqE=; b=EcOrLEHLGL2ZVOsGu6Fu4z219k8G7clay8Xcrp/SrNfE+1FKObbcysoZ0RjbHs2BNKltK9 wCMpLQpiybYa3pXRYoPAkGVJpymB/oPn0H81L3cpKv0CyY+6A5aePy+NIEYyW9WvhGoleI bwi5dr23Ea+jNjibDE7za+3jhux9YSs= Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-290-TGH7Kd8IMq2_ozX7K9dtww-1; Mon, 05 Apr 2021 10:15:58 -0400 X-MC-Unique: TGH7Kd8IMq2_ozX7K9dtww-1 Received: by mail-ed1-f69.google.com with SMTP id j18so8768053edv.6 for ; Mon, 05 Apr 2021 07:15:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version:content-transfer-encoding; bh=3odf2vfILdNMkO2s2+U+l93jP5VUsQZO+yjT8s2izqE=; b=gGerLHuSDtMWe2l5iN8eJA9boK72RI4//EjxpiQ8RFMZw9kYUV2w+RUTGCNBLVNJfp S+TwIzEkF/YIESJNN5bzEtkZoTKIKER/dAxLdK8yM3vE9f17SQAV7Hn66nqd6owd2I6W s9IC0gRxiZEaGLk4gKVA3dK6ZmRfgMr8CQJncMjWsFUauhV9LsEHxv7XtiO5DfJac8R7 csVJY2TzUz4QOe1HiFG84QIBMxfvRcQZw+MgHWxkxtOQvcxnlYUmbvseDJBzvGCSmpKo XLTXxodfk0JdOkfr5Re5cC0c9bj7/PLvY33zS8zpY+KOT5qKAmT3c59ORyjbeVQ9NZ+x UV2A== X-Gm-Message-State: AOAM5332PB7D4pJDm5CWY+adMGDrkGL6iUAPbuveE0rdenMRHEMJfkg9 N7PeJ2H4iZqG2uX6rxfJ7yv9JzWaYYNWlk0DAO7y7nL67WMCEvPL82qoy0Ltx+la/Fr7mwyrt9S SEZm+eevPD4gg X-Received: by 2002:a05:6402:2786:: with SMTP id b6mr18247941ede.310.1617632157269; Mon, 05 Apr 2021 07:15:57 -0700 (PDT) X-Google-Smtp-Source: ABdhPJw/kaX4UTFfF7Bmv/p6D2RrzmNIRppR03nf0JaMtLdLykhr1IltaGNuDma3/1383pOHhJZ7pw== X-Received: by 2002:a05:6402:2786:: with SMTP id b6mr18247907ede.310.1617632157072; Mon, 05 Apr 2021 07:15:57 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id g22sm8920711ejm.69.2021.04.05.07.15.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Apr 2021 07:15:56 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id C73AB1802E8; Mon, 5 Apr 2021 16:15:54 +0200 (CEST) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Jiri Olsa , Alexei Starovoitov Cc: Jiri Olsa , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , netdev@vger.kernel.org, bpf@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh Subject: Re: [RFC PATCH bpf-next 1/4] bpf: Allow trampoline re-attach In-Reply-To: References: <20210328112629.339266-1-jolsa@kernel.org> <20210328112629.339266-2-jolsa@kernel.org> <87blavd31f.fsf@toke.dk> <20210403182155.upi6267fh3gsdvrq@ast-mbp> X-Clacks-Overhead: GNU Terry Pratchett Date: Mon, 05 Apr 2021 16:15:54 +0200 Message-ID: <87ft04rf51.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Jiri Olsa writes: > On Sat, Apr 03, 2021 at 11:21:55AM -0700, Alexei Starovoitov wrote: >> On Sat, Apr 03, 2021 at 01:24:12PM +0200, Toke H=C3=B8iland-J=C3=B8rgens= en wrote: >> > > if (!prog->aux->dst_trampoline && !tgt_prog) { >> > > - err =3D -ENOENT; >> > > - goto out_unlock; >> > > + /* >> > > + * Allow re-attach for tracing programs, if it's currently >> > > + * linked, bpf_trampoline_link_prog will fail. >> > > + */ >> > > + if (prog->type !=3D BPF_PROG_TYPE_TRACING) { >> > > + err =3D -ENOENT; >> > > + goto out_unlock; >> > > + } >> > > + if (!prog->aux->attach_btf) { >> > > + err =3D -EINVAL; >> > > + goto out_unlock; >> > > + } >> >=20 >> > I'm wondering about the two different return codes here. Under what >> > circumstances will aux->attach_btf be NULL, and why is that not an >> > ENOENT error? :) >>=20 >> The feature makes sense to me as well. >> I don't quite see how it would get here with attach_btf =3D=3D NULL. >> Maybe WARN_ON then? > > right, that should be always there > >> Also if we're allowing re-attach this way why exclude PROG_EXT and LSM? >>=20 > > I was enabling just what I needed for the test, which is so far > the only use case.. I'll see if I can enable that for all of them How would that work? For PROG_EXT we clear the destination on the first attach (to avoid keeping a ref on it), so re-attach can only be done with an explicit target (which already works just fine)... -Toke