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=-17.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 10FF7C4320A for ; Sat, 14 Aug 2021 00:26:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DB6C560F14 for ; Sat, 14 Aug 2021 00:26:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235856AbhHNA0q (ORCPT ); Fri, 13 Aug 2021 20:26:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235776AbhHNA0o (ORCPT ); Fri, 13 Aug 2021 20:26:44 -0400 Received: from mail-yb1-xb30.google.com (mail-yb1-xb30.google.com [IPv6:2607:f8b0:4864:20::b30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1CC25C061756; Fri, 13 Aug 2021 17:26:17 -0700 (PDT) Received: by mail-yb1-xb30.google.com with SMTP id o126so13787426ybo.7; Fri, 13 Aug 2021 17:26:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ZoysL5lDfLKZ+wWbRS+l3epQ03ts/jCJh76pqNcdD48=; b=Cpt0mHNLdfgtg3TtpzUCxAgqCRq5+1ViLV0JZoWtHfmYNIeHmijYps3VChf0HLMFZL uaSr8YM+0MJLdfbQVgxqSM6AYCGhKW0jKPEUye2QimSXkHHXbgKZK/lhDUlhkXiXNMfr RmQuzlL5hIcsOYDM6EtND9VdSe1Oc5s91mUQ7tT+REyigr4gMBXEm6ZOSEdCmAbi6Gy2 z7tmMmQfmewJ6vpeJq5zibx6GW9bVSk/euoCUQMp/oNOTgGrPTunJBp7W6C+LD2jjKXP eJpUQIZ+ZeXWTeoOScUUV9QFWnjH42/H4pcHXjc+7CG17BjBA3fAkwfFDkAGG8tEep/n qAHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ZoysL5lDfLKZ+wWbRS+l3epQ03ts/jCJh76pqNcdD48=; b=OmbEmQblhnxbCrc7G1Bl77h9qITjMomReRMn4yrWKsncascaqx7CoThzrYugiiii0f z2Gr6g6ysUHAq10YBVkQ7dmpQBOzydV+VzC/RzdPoVbJ9SxHpFuAKJkxtLraX80xLC2T yOLjNDv8fYZIk8GhGc/Q9b4WRaUGjXIAQqKkHALbxhsUfYpIcmO6x7dtBKoy2EtroUXF +AlZW+cnps8OVGtCHWzjBJLm/yDFUvB1IHxvAtdiX7kFtSYB1CIc3v436PddgEXGfP60 psI/9DAZWydyuWNwBsf9Q5IfcnbPBsDM5qatDZy/rcZiDx5S64OeVwZ2oFl9bMMTn7BI V2nw== X-Gm-Message-State: AOAM530AWbcxTibNW0H7XM5nLPJnRql7ExzoFrAY7e0NChhMNrAvWEBm VP6hdsjyu2xN/YN0ULpiixIHemlTVS7OkT8GjWo= X-Google-Smtp-Source: ABdhPJyDoooqsgG36cAMj9eA/V02V86WgBcnBXv/KkrUh5Sp4rDXdwKPZgC/VSTivyYIJ8d2oNb2zfZOenmmu53m5Ak= X-Received: by 2002:a25:4941:: with SMTP id w62mr6313920yba.230.1628900776300; Fri, 13 Aug 2021 17:26:16 -0700 (PDT) MIME-Version: 1.0 References: <20210814002101.33742-1-kuniyu@amazon.co.jp> In-Reply-To: <20210814002101.33742-1-kuniyu@amazon.co.jp> From: Andrii Nakryiko Date: Fri, 13 Aug 2021 17:26:05 -0700 Message-ID: Subject: Re: [PATCH v5 bpf-next 3/4] selftest/bpf: Implement sample UNIX domain socket iterator program. To: Kuniyuki Iwashima Cc: Andrii Nakryiko , Alexei Starovoitov , Benjamin Herrenschmidt , bpf , Daniel Borkmann , "David S. Miller" , john fastabend , Martin Lau , KP Singh , Jakub Kicinski , Kuniyuki Iwashima , Networking , Song Liu , Yonghong Song Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, Aug 13, 2021 at 5:21 PM Kuniyuki Iwashima wrote: > > From: Andrii Nakryiko > Date: Fri, 13 Aug 2021 16:25:53 -0700 > > On Thu, Aug 12, 2021 at 9:46 AM Kuniyuki Iwashima wrote: > > > > > > The iterator can output almost the same result compared to /proc/net/unix. > > > The header line is aligned, and the Inode column uses "%8lu" because "%5lu" > > > can be easily overflown. > > > > > > # cat /sys/fs/bpf/unix > > > Num RefCount Protocol Flags Type St Inode Path > > > > It's totally my OCD, but why the column name is not aligned with > > values? I mean the "Inode" column. It's left aligned, but values > > (numbers) are right-aligned? I'd fix that while applying, but I can't > > apply due to selftests failures, so please take a look. > > Ah, honestly, I've felt something strange about the column... will fix it! > > > > > > > > > ffff963c06689800: 00000002 00000000 00010000 0001 01 18697 private/defer > > > ffff963c7c979c00: 00000002 00000000 00000000 0001 01 598245 @Hello@World@ > > > > > > # cat /proc/net/unix > > > Num RefCount Protocol Flags Type St Inode Path > > > ffff963c06689800: 00000002 00000000 00010000 0001 01 18697 private/defer > > > ffff963c7c979c00: 00000002 00000000 00000000 0001 01 598245 @Hello@World@ > > > > > > Note that this prog requires the patch ([0]) for LLVM code gen. Thanks to > > > Yonghong Song for analysing and fixing. > > > > > > [0] https://reviews.llvm.org/D107483 > > > > > > Signed-off-by: Kuniyuki Iwashima > > > Acked-by: Yonghong Song > > > --- > > > > This selftests breaks test_progs-no_alu32 ([0], the error log is super > > long and can freeze browser; it looks like an infinite loop and BPF > > verifier just keeps reporting it until it runs out of 1mln > > instructions or something). Please check what's going on there, I > > can't land it as it is right now. > > > > [0] https://github.com/kernel-patches/bpf/runs/3326071112?check_suite_focus=true#step:6:124288 > > > > > > > tools/testing/selftests/bpf/README.rst | 38 +++++++++ > > > .../selftests/bpf/prog_tests/bpf_iter.c | 16 ++++ > > > tools/testing/selftests/bpf/progs/bpf_iter.h | 8 ++ > > > .../selftests/bpf/progs/bpf_iter_unix.c | 77 +++++++++++++++++++ > > > .../selftests/bpf/progs/bpf_tracing_net.h | 4 + > > > 5 files changed, 143 insertions(+) > > > create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_unix.c > > > > > > > [...] > > > > > + /* The name of the abstract UNIX domain socket starts > > > + * with '\0' and can contain '\0'. The null bytes > > > + * should be escaped as done in unix_seq_show(). > > > + */ > > > + int i, len; > > > + > > > > no_alu32 variant probably isn't happy about using int for this, it > > probably does << 32, >> 32 dance and loses track of actual value in > > the loop. You can try using u64 instead. > > Sorry, I missed the no_alu32 test. > Changing int to __u64 fixed the error, thanks! > > > > > > > + len = unix_sk->addr->len - sizeof(short); > > > + > > > + BPF_SEQ_PRINTF(seq, " @"); > > > + > > > + /* unix_mkname() tests this upper bound. */ > > > + if (len < sizeof(struct sockaddr_un)) > > > + for (i = 1; i < len; i++) > > > > if you move above if inside the loop to break out of the loop, does it > > change how Clang generates code? > > > > for (i = 1; i < len i++) { > > if (i >= sizeof(struct sockaddr_un)) > > break; > > BPF_SEQ_PRINTF(...); > > } > > Yes, but there seems little defference. > Which is preferable? > > ---8<--- > before (for inside if) <- -> after (if inside loop) > 96: 07 08 00 00 fe ff ff ff r8 += -2 | ; for (i = 1; i < len; i++) { > ; if (len < sizeof(struct sockaddr_un)) | 97: bf 81 00 00 00 00 00 00 r1 = r8 > 97: 25 08 10 00 6d 00 00 00 if r8 > 109 goto +16 | 98: 07 01 00 00 fc ff ff ff r1 += -4 > ; for (i = 1; i < len; i++) | 99: 25 01 12 00 6b 00 00 00 if r1 > 107 goto +18 > 98: a5 08 0f 00 02 00 00 00 if r8 < 2 goto +15 | 100: 07 08 00 00 fe ff ff ff r8 += -2 > 99: b7 09 00 00 01 00 00 00 r9 = 1 | 101: b7 09 00 00 01 00 00 00 r9 = 1 > 100: 05 00 16 00 00 00 00 00 goto +22 | 102: b7 06 00 00 02 00 00 00 r6 = 2 > | 103: 05 00 17 00 00 00 00 00 goto +23 > ... > 111: 85 00 00 00 7e 00 00 00 call 126 | 113: b4 05 00 00 08 00 00 00 w5 = 8 > ; for (i = 1; i < len; i++) | 114: 85 00 00 00 7e 00 00 00 call 126 > 112: 07 09 00 00 01 00 00 00 r9 += 1 | ; for (i = 1; i < len; i++) { > 113: ad 89 09 00 00 00 00 00 if r9 < r8 goto +9 | 115: 25 08 02 00 6d 00 00 00 if r8 > 109 goto +2 > > 116: 07 09 00 00 01 00 00 00 r9 += 1 > > ; for (i = 1; i < len; i++) { > > 117: ad 89 09 00 00 00 00 00 if r9 < r8 goto +9 > ---8<--- > Have you tried running the variant I proposed on Clang without Yonghong's recent fix? I wonder if it works without that fix (not that there is anything wrong about the fix, but if we can avoid depending on it, it would be great). > > > > > > > > + BPF_SEQ_PRINTF(seq, "%c", > > > + unix_sk->addr->name->sun_path[i] ?: > > > + '@'); > > > + } > > > + } > > > + > > > + BPF_SEQ_PRINTF(seq, "\n"); > > > + > > > + return 0; > > > +} > > > diff --git a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h > > > index 3af0998a0623..eef5646ddb19 100644 > > > --- a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h > > > +++ b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h > > > @@ -5,6 +5,10 @@ > > > #define AF_INET 2 > > > #define AF_INET6 10 > > > > > > +#define __SO_ACCEPTCON (1 << 16) > > > +#define UNIX_HASH_SIZE 256 > > > +#define UNIX_ABSTRACT(unix_sk) (unix_sk->addr->hash < UNIX_HASH_SIZE) > > > + > > > #define SOL_TCP 6 > > > #define TCP_CONGESTION 13 > > > #define TCP_CA_NAME_MAX 16 > > > -- > > > 2.30.2 > > >