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 C4B54C00140 for ; Tue, 16 Aug 2022 02:08:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240567AbiHPCIV (ORCPT ); Mon, 15 Aug 2022 22:08:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233436AbiHPCHx (ORCPT ); Mon, 15 Aug 2022 22:07:53 -0400 Received: from mail-ed1-x532.google.com (mail-ed1-x532.google.com [IPv6:2a00:1450:4864:20::532]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E47AE10E7A1; Mon, 15 Aug 2022 15:00:02 -0700 (PDT) Received: by mail-ed1-x532.google.com with SMTP id y3so11202754eda.6; Mon, 15 Aug 2022 15:00:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc; bh=T3BNXnM8/uSXVm7gYnNlnagKr/r09Wg9R1KlljM+2MI=; b=Ru+YRuUfY4mqjyaatb7nZlVXi+2e4yAddoTV+qYz70z9AsblRHunci931h5+VVqL8q xYFTQGRQywswIpVid50GCCRKELYsMCMIcpgsXT34sYX42AQOByUpmBG5oIUlKWD0Pn86 pGonC4R1iZMkbYDLcMkgTjE0zlkk7Fg+KotGF61lrCDtZsud8W1hsWVMoaCwKjQLgcCC CFMtEZqdlDf3S+lQZz7UdCoNTb0mylVkYS0Y81KVYbnsSrLggG86u+lz30jkuOOVlujF F2lRzrdsV5Vnh5gbyQrfyBegB4qQceqXOXygo7bO2q/I4Ywx32azEfYAY1drn/laqwEq zsMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc; bh=T3BNXnM8/uSXVm7gYnNlnagKr/r09Wg9R1KlljM+2MI=; b=Kl/YqiXQrOnkMQDOFaysuAgqMJpnauWhxY8xAExJ8d9GjqCLBS/PBUloiiJAkjrEzk rZ010J3EJ6PeIq7OgctH9m1NxH4wKmGIrTsTkYkGonzKOWAmFYspM9gxYqxolrxLBsD3 xxQ+lc43I8FPo1HZ8hPQiiGxX69GGZdPlvKAz8T3iOcLhCaAo/xy27s+wob8hPcLZ+8V +izVS+oPt0TeblPQzlsfFQAeyxn9YJ7bOEtRVBRIHdVQwQKjl7pVUzshnh9AxQo66YzO uPcl3wi9ZUftjStiGQrorq0skmPqq6/38a89/iLKNXhAODU8cjMVAqL9jQb4UkbR+aDg da9g== X-Gm-Message-State: ACgBeo06bNcVGpfYAp2fEqg3L26kY8jplF7pXaZET11xbbAKK/hN5sv1 mQvF5RJ4r+1+OaRcpQDYJGZ2m7iEUSlU7Dg5prs= X-Google-Smtp-Source: AA6agR4Xpty0a0xX36T/oYkX/50SCihLUbIHHrh4aJgB/OVvGj11f25UJ08jEFHcYWKLZnRnU5RJZtHmYKRi44b2rx4= X-Received: by 2002:a50:ed82:0:b0:43d:5334:9d19 with SMTP id h2-20020a50ed82000000b0043d53349d19mr16025224edr.232.1660600801439; Mon, 15 Aug 2022 15:00:01 -0700 (PDT) MIME-Version: 1.0 References: <20220813000936.6464-1-liuhangbin@gmail.com> In-Reply-To: From: Andrii Nakryiko Date: Mon, 15 Aug 2022 14:59:50 -0700 Message-ID: Subject: Re: [PATCHv2 bpf-next] libbpf: making bpf_prog_load() ignore name if kernel doesn't support To: Quentin Monnet Cc: Hangbin Liu , netdev@vger.kernel.org, Andrii Nakryiko , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , bpf@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Mon, Aug 15, 2022 at 8:36 AM Quentin Monnet wrote: > > On 13/08/2022 01:09, Hangbin Liu wrote: > > Similar with commit 10b62d6a38f7 ("libbpf: Add names for auxiliary maps"), > > let's make bpf_prog_load() also ignore name if kernel doesn't support > > program name. > > > > To achieve this, we need to call sys_bpf_prog_load() directly in > > probe_kern_prog_name() to avoid circular dependency. sys_bpf_prog_load() > > also need to be exported in the libbpf_internal.h file. > > > > Signed-off-by: Hangbin Liu > > --- > > v2: move sys_bpf_prog_load definition to libbpf_internal.h. memset attr > > to 0 specifically to aviod padding. > > --- > > tools/lib/bpf/bpf.c | 6 ++---- > > tools/lib/bpf/libbpf.c | 12 ++++++++++-- > > tools/lib/bpf/libbpf_internal.h | 3 +++ > > 3 files changed, 15 insertions(+), 6 deletions(-) > > > > diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c > > index 6a96e665dc5d..575867d69496 100644 > > --- a/tools/lib/bpf/bpf.c > > +++ b/tools/lib/bpf/bpf.c > > @@ -84,9 +84,7 @@ static inline int sys_bpf_fd(enum bpf_cmd cmd, union bpf_attr *attr, > > return ensure_good_fd(fd); > > } > > > > -#define PROG_LOAD_ATTEMPTS 5 > > - > > -static inline int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts) > > +int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts) > > { > > int fd; > > > > @@ -263,7 +261,7 @@ int bpf_prog_load(enum bpf_prog_type prog_type, > > attr.prog_ifindex = OPTS_GET(opts, prog_ifindex, 0); > > attr.kern_version = OPTS_GET(opts, kern_version, 0); > > > > - if (prog_name) > > + if (prog_name && kernel_supports(NULL, FEAT_PROG_NAME)) > > libbpf_strlcpy(attr.prog_name, prog_name, sizeof(attr.prog_name)); > > attr.license = ptr_to_u64(license); > > > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > > index 3f01f5cd8a4c..4a351897bdcc 100644 > > --- a/tools/lib/bpf/libbpf.c > > +++ b/tools/lib/bpf/libbpf.c > > @@ -4419,10 +4419,18 @@ static int probe_kern_prog_name(void) > > BPF_MOV64_IMM(BPF_REG_0, 0), > > BPF_EXIT_INSN(), > > }; > > - int ret, insn_cnt = ARRAY_SIZE(insns); > > + union bpf_attr attr; > > + int ret; > > + > > + memset(&attr, 0, sizeof(attr)); > > + attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER; > > + attr.license = ptr_to_u64("GPL"); > > + attr.insns = ptr_to_u64(insns); > > + attr.insn_cnt = (__u32)ARRAY_SIZE(insns); > > + libbpf_strlcpy(attr.prog_name, "test", sizeof(attr.prog_name)); > > > > /* make sure loading with name works */ > > - ret = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, "test", "GPL", insns, insn_cnt, NULL); > > + ret = sys_bpf_prog_load(&attr, sizeof(attr), PROG_LOAD_ATTEMPTS); > > return probe_fd(ret); > > } > > > > diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h > > index 4135ae0a2bc3..377642ff51fc 100644 > > --- a/tools/lib/bpf/libbpf_internal.h > > +++ b/tools/lib/bpf/libbpf_internal.h > > @@ -573,4 +573,7 @@ static inline bool is_pow_of_2(size_t x) > > return x && (x & (x - 1)) == 0; > > } > > > > +#define PROG_LOAD_ATTEMPTS 5 > > +int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts); > > + > > #endif /* __LIBBPF_LIBBPF_INTERNAL_H */ > > Looks good to me, thanks! > > Acked-by: Quentin Monnet I did a small adjustment to not fill out entire big bpf_attr union completely (and added a bit more meaningful "libbpf_nametest" prog name): $ git diff --staged diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 4a351897bdcc..f05dd61a8a7f 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4415,6 +4415,7 @@ static int probe_fd(int fd) static int probe_kern_prog_name(void) { + const size_t attr_sz = offsetofend(union bpf_attr, prog_name); struct bpf_insn insns[] = { BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), @@ -4422,12 +4423,12 @@ static int probe_kern_prog_name(void) union bpf_attr attr; int ret; - memset(&attr, 0, sizeof(attr)); + memset(&attr, 0, attr_sz); attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER; attr.license = ptr_to_u64("GPL"); attr.insns = ptr_to_u64(insns); attr.insn_cnt = (__u32)ARRAY_SIZE(insns); - libbpf_strlcpy(attr.prog_name, "test", sizeof(attr.prog_name)); + libbpf_strlcpy(attr.prog_name, "libbpf_nametest", sizeof(attr.prog_name)); Pushed to bpf-next, thanks!