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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 E058DC433DF for ; Tue, 30 Jun 2020 13:58:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B59B820774 for ; Tue, 30 Jun 2020 13:58:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="T6LZm19o" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387477AbgF3N6v (ORCPT ); Tue, 30 Jun 2020 09:58:51 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:43072 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728306AbgF3N6u (ORCPT ); Tue, 30 Jun 2020 09:58:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1593525529; 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=vrr9+UDr/nL1jLcaePhj7X9mSwa+9jdHrZ+GGReV/Jo=; b=T6LZm19osFJBFP9ZYqIKvWS7PdHhBkA0/Lh0CSx54L2ThmZfqXvVywpxeFKAoIB8NBSLgk ov1MYXkxh5zo3/SNJYnE1rk0OlSA0G8qnyvpaonaar0ZR7jBhvAkrBsgq6nC9fnhNRBpU3 Nfuy5Dv9kUm/5k7rSDVQ/zOug5fAiNg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-201-89yaZnypPKmKN1Pax-Ichg-1; Tue, 30 Jun 2020 09:58:43 -0400 X-MC-Unique: 89yaZnypPKmKN1Pax-Ichg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6782E15676; Tue, 30 Jun 2020 13:55:43 +0000 (UTC) Received: from krava (unknown [10.40.192.137]) by smtp.corp.redhat.com (Postfix) with SMTP id 84EAA60C81; Tue, 30 Jun 2020 13:55:39 +0000 (UTC) Date: Tue, 30 Jun 2020 15:55:38 +0200 From: Jiri Olsa To: Andrii Nakryiko Cc: Jiri Olsa , Alexei Starovoitov , Daniel Borkmann , Networking , bpf , Song Liu , Yonghong Song , Martin KaFai Lau , David Miller , John Fastabend , Wenbo Zhang , KP Singh , Andrii Nakryiko , Brendan Gregg , Florent Revest , Al Viro Subject: Re: [PATCH v4 bpf-next 00/14] bpf: Add d_path helper Message-ID: <20200630135538.GB3071036@krava> References: <20200625221304.2817194-1-jolsa@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Jun 29, 2020 at 06:54:30PM -0700, Andrii Nakryiko wrote: > On Thu, Jun 25, 2020 at 4:47 PM Jiri Olsa wrote: > > > > hi, > > adding d_path helper to return full path for 'path' object. > > > > In a preparation for that, this patchset also adds support for BTF ID > > whitelists, because d_path can't be called from any probe due to its > > locks usage. The whitelists allow verifier to check if the caller is > > one of the functions from the whitelist. > > > > The whitelist is implemented in a generic way. This patchset introduces > > macros that allow to define lists of BTF IDs, which are compiled in > > the kernel image in a new .BTF.ids ELF section. > > > > The generic way of BTF ID lists allows us to use them in other places > > in kernel (than just for whitelists), that could use static BTF ID > > values compiled in and it's also implemented in this patchset. > > > > I originally added and used 'file_path' helper, which did the same, > > but used 'struct file' object. Then realized that file_path is just > > a wrapper for d_path, so we'd cover more calling sites if we add > > d_path helper and allowed resolving BTF object within another object, > > so we could call d_path also with file pointer, like: > > > > bpf_d_path(&file->f_path, buf, size); > > > > This feature is mainly to be able to add dpath (filepath originally) > > function to bpftrace: > > > > # bpftrace -e 'kfunc:vfs_open { printf("%s\n", dpath(args->path)); }' > > > > v4 changes: > > - added ID sanity checks in btf_resolve_helper_id [Andrii] > > - resolve bpf_ctx_convert via BTF_ID [Andrii] > > - keep bpf_access_type in btf_struct_access [Andrii] > > - rename whitelist to se and use struct btf_id_set [Andrii] > > - several fixes for d_path prog/verifier tests [Andrii] > > - added union and typedefs types support [Andrii] > > - rename btfid to resolve_btfids [Andrii] > > - fix segfault in resolve_btfids [John] > > - rename section from .BTF_ids .BTF.ids (following .BTF.ext example) > > - add .BTF.ids section info into btf.rst [John] > > - updated over letter with more details [John] > > > > Also available at: > > https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git > > bpf/d_path > > > > thanks, > > jirka > > > > > > --- > > Have you considered splitting this series into two? One with BTF ID > resolution and corresponding patches. I'm pretty confident in that one > and it seems ready (with some minor selftest changes). Then, > separately, d_path and that sub-struct address logic. That one depends > on the first one, but shouldn't really block BTF ID resolution from > going in sooner. ok, will split it and send the first part for now jirka