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=-8.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 9C12FC7618F for ; Fri, 26 Jul 2019 21:28:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6B46B217D9 for ; Fri, 26 Jul 2019 21:28:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=fomichev-me.20150623.gappssmtp.com header.i=@fomichev-me.20150623.gappssmtp.com header.b="dfnglxIX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728342AbfGZV2U (ORCPT ); Fri, 26 Jul 2019 17:28:20 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:38468 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727476AbfGZV2U (ORCPT ); Fri, 26 Jul 2019 17:28:20 -0400 Received: by mail-pg1-f194.google.com with SMTP id f5so16523019pgu.5 for ; Fri, 26 Jul 2019 14:28:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fomichev-me.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=+z7GOTmT3nNgKC279a8ACROVHWGzWXxrdH8l/jHT3m0=; b=dfnglxIX5OjNlpmG1N11VkmIjJmPc4py8gPeqZG7SeqK+Ggtjz8el1QhSSWSwy4CiW APou4pPA1qWnTFzT/WcJK4gbAglLnZf/E/XRTHiVAQT1qx1tLbcVCN2IW+kIE34EgVQ0 pI/Wou0mxvZ8CdfQj9xcKmc9LW5bm+75pcFsqnygR4c2ji6loRsu0XhISQm1xOBmr5AQ riKBcqGSJ3wXbmX0WkBsNk2ESZSc0ZOdljS15Oqi14X1kbp4hM3BYN7mARRzmEegkaRG g6oq7UFVgpKO5rw2cRys81c9hECP32198yeYQnaqEiMsPhDMsDmKnXeBdrLVlA20iSwg INjw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=+z7GOTmT3nNgKC279a8ACROVHWGzWXxrdH8l/jHT3m0=; b=pa+ezDziVnpyTu2GQbqLh+4hsGPM4Beg/uYt0wYS9hX3I2z+/HU7+HpD5WeuZgocKb b7dw1jYl9CfYFPtXWl42GC+zc9v5cKslsrz7woRKFO4Y75jak03PNw1WfGNzx5De98c2 nsRqp2OiYoHGbIneSnGBLEtc9n+aDz0MSwRmf78nT4Xzwd1CnsVpWhFybFOO0q0abPtb CpDTVRySoTSym6QX3VcUkXwmFGJzBjiJSu6fwkB6LXdIAQ2eMn1fFdUma6Vgxv7dCVTh OQBc1YflPLn6F5QqtzUBB/yU3y96E1R0XvVqUY/PuEkYH2L9KRDe2tpe+1WLraJED5a+ /yUQ== X-Gm-Message-State: APjAAAUmcxUnkqolVY0aIYK4h28IKHSfvwvepFb6IX+1ZOlqDJDiOjNv AfDo+0BywTqvMxpQluOiCGNbq/p8 X-Google-Smtp-Source: APXvYqwtzGX+2PfYSt224WPJM4zPXeFd7Zlsy3vH1nvn/GL9oXPV+mMKveijM/0q5d0SdlMgeF6itw== X-Received: by 2002:a63:5f09:: with SMTP id t9mr59942983pgb.351.1564176499249; Fri, 26 Jul 2019 14:28:19 -0700 (PDT) Received: from localhost ([2601:646:8f00:18d9:d0fa:7a4b:764f:de48]) by smtp.gmail.com with ESMTPSA id 185sm54366553pfd.125.2019.07.26.14.28.18 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Fri, 26 Jul 2019 14:28:18 -0700 (PDT) Date: Fri, 26 Jul 2019 14:28:18 -0700 From: Stanislav Fomichev To: Andrii Nakryiko Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, ast@fb.com, daniel@iogearbox.net, andrii.nakryiko@gmail.com, kernel-team@fb.com Subject: Re: [PATCH bpf-next 4/9] libbpf: add libbpf_swap_print to get previous print func Message-ID: <20190726212818.GC24397@mini-arch> References: <20190726203747.1124677-1-andriin@fb.com> <20190726203747.1124677-5-andriin@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190726203747.1124677-5-andriin@fb.com> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 07/26, Andrii Nakryiko wrote: > libbpf_swap_print allows to restore previously set print function. > This is useful when running many independent test with one default print > function, but overriding log verbosity for particular subset of tests. Can we change the return type of libbpf_set_print instead and return the old function from it? Will it break ABI? > Signed-off-by: Andrii Nakryiko > --- > tools/lib/bpf/libbpf.c | 8 ++++++++ > tools/lib/bpf/libbpf.h | 1 + > tools/lib/bpf/libbpf.map | 5 +++++ > 3 files changed, 14 insertions(+) > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > index 8741c39adb1c..0c254b6c9685 100644 > --- a/tools/lib/bpf/libbpf.c > +++ b/tools/lib/bpf/libbpf.c > @@ -79,6 +79,14 @@ void libbpf_set_print(libbpf_print_fn_t fn) > __libbpf_pr = fn; > } > > +libbpf_print_fn_t libbpf_swap_print(libbpf_print_fn_t fn) > +{ > + libbpf_print_fn_t old_print_fn = __libbpf_pr; > + > + __libbpf_pr = fn; > + return old_print_fn; > +} > + > __printf(2, 3) > void libbpf_print(enum libbpf_print_level level, const char *format, ...) > { > diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h > index 5cbf459ece0b..4e0aa893571f 100644 > --- a/tools/lib/bpf/libbpf.h > +++ b/tools/lib/bpf/libbpf.h > @@ -58,6 +58,7 @@ typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level, > const char *, va_list ap); > > LIBBPF_API void libbpf_set_print(libbpf_print_fn_t fn); > +LIBBPF_API libbpf_print_fn_t libbpf_swap_print(libbpf_print_fn_t fn); > > /* Hide internal to user */ > struct bpf_object; > diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map > index f9d316e873d8..e211c38ddc43 100644 > --- a/tools/lib/bpf/libbpf.map > +++ b/tools/lib/bpf/libbpf.map > @@ -184,3 +184,8 @@ LIBBPF_0.0.4 { > perf_buffer__new_raw; > perf_buffer__poll; > } LIBBPF_0.0.3; > + > +LIBBPF_0.0.5 { > + global: > + libbpf_swap_print; > +} LIBBPF_0.0.4; > -- > 2.17.1 >