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=-11.7 required=3.0 tests=BAYES_00,BOMB_FREEM, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,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 32605C433E6 for ; Sat, 6 Feb 2021 08:33:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8E0764FA8 for ; Sat, 6 Feb 2021 08:33:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229751AbhBFIdC (ORCPT ); Sat, 6 Feb 2021 03:33:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57862 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229492AbhBFIc6 (ORCPT ); Sat, 6 Feb 2021 03:32:58 -0500 Received: from mail-io1-xd30.google.com (mail-io1-xd30.google.com [IPv6:2607:f8b0:4864:20::d30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B4E4C061756; Sat, 6 Feb 2021 00:32:18 -0800 (PST) Received: by mail-io1-xd30.google.com with SMTP id q7so9782474iob.0; Sat, 06 Feb 2021 00:32:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:reply-to:from:date:message-id :subject:to:cc; bh=8jZ/SgN+hKQexkXrpdxS/cjJFDMUx4y5qzsPaB3r9UM=; b=awgbKCs8hGG/j8aWm9+PSGJW/gpQwDoxFN8d5jEVurL3h2EXoPF3n1IWRVcOJM9eWo /CRReYw66XW0WjAPFA2yRsw9hB5XBYyf3S1uFnu+9c1R9YlKcW+Ug6Iaj2A+xnX5Bf6M X3CJoGVsTotfssaZVzPdzA3VG4DmHiVwwTUYPJgcgl715ktNtZQI0XYqn6ifhSzf3oyY AjG5lrEZk6mBEUCwoxolK8KM88IRGhuvLtyN8AdR+gfiIZgoUwmtytvVj1xOCVJZk5BP G6oL9QNNSrQkOhdowIklRBK1K5vR/K/ftk7O/bVpu677wQLMSHURn73gpgoqmVMcUQwd O1uQ== 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:reply-to :from:date:message-id:subject:to:cc; bh=8jZ/SgN+hKQexkXrpdxS/cjJFDMUx4y5qzsPaB3r9UM=; b=Tlc3NzdOXiAWzS70UZ5URN/81tPTiSngWEJL5/vfECyIFcsTV5+bbK7tBs29c4ZK+q LK/xjtO6f7j8k/IObgwzZ+irITgWTFl6/V+uR0qcSZDCQhzgcWZ912k/KncOXKF7kH/I 8qjy8vVZx/K8jvdxDitCkWD8FbEak7KqwcdVRn1pRMD8Zj1MEhc7XQNtefPV98ptrjjA cyJtzNQzpdPqlgsNNXhmZDWZR5Sf/tXBQUlc3HoGDiND+quIbdr6oC3R6FsuLyrHtplY I+vM4Fwzp2+OHYpHKsKemrwcvD4kDWBOpIR8KFx811JRkdz/YO83KobYH4W1iDZg4+kW h2Mw== X-Gm-Message-State: AOAM5327cZnn6v19uED1BY3w5gejM1bS6AbA1IL/RR6ciU0vLaiZGw8/ IfL+uk1v3JJQnpPVyy9bpwAnuDfWamjuDRG/LuRn2vVQmQbkOk3X X-Google-Smtp-Source: ABdhPJxiJPGHzIddWBjHhXwlEnZDx9AdnlFOw9kn4/UwHkVyPXpy02KSmdRvPOmyTDfla4ubSwdrdCGGERz3k6s7IbA= X-Received: by 2002:a6b:f112:: with SMTP id e18mr7451113iog.57.1612600337723; Sat, 06 Feb 2021 00:32:17 -0800 (PST) MIME-Version: 1.0 References: <20210204220741.GA920417@kernel.org> <20210205152823.GD920417@kernel.org> <20210205192446.GH920417@kernel.org> <8ff11fa8-46cd-5f20-b988-20e65e122507@fb.com> In-Reply-To: <8ff11fa8-46cd-5f20-b988-20e65e122507@fb.com> Reply-To: sedat.dilek@gmail.com From: Sedat Dilek Date: Sat, 6 Feb 2021 09:32:06 +0100 Message-ID: Subject: Re: ERROR: INT DW_ATE_unsigned_1 Error emitting BTF type To: Yonghong Song Cc: Masahiro Yamada , Arnaldo Carvalho de Melo , Arnaldo Carvalho de Melo , dwarves@vger.kernel.org, Linux Kernel Mailing List , bpf@vger.kernel.org, Jiri Olsa , Jan Engelhardt , Domenico Andreoli , Matthias Schwarzott , Andrii Nakryiko , Mark Wieelard , Paul Moore , Ondrej Mosnacek , =?UTF-8?Q?Daniel_P=2E_Berrang=C3=A9?= , Tom Stellard Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Feb 6, 2021 at 9:27 AM Yonghong Song wrote: > > > > On 2/5/21 10:52 PM, Sedat Dilek wrote: > > On Sat, Feb 6, 2021 at 7:26 AM Sedat Dilek wrote: > >> > >> On Sat, Feb 6, 2021 at 6:53 AM Sedat Dilek wrote: > >>> > >>> On Sat, Feb 6, 2021 at 6:44 AM Sedat Dilek wrote: > >>>> > >>>> On Sat, Feb 6, 2021 at 4:34 AM Sedat Dilek wrote: > >>>>> > >>>>> On Fri, Feb 5, 2021 at 10:54 PM Yonghong Song wrote: > >>>>>> > >>>>>> > >>>>>> > >>>>>> On 2/5/21 12:31 PM, Sedat Dilek wrote: > >>>>>>> On Fri, Feb 5, 2021 at 9:03 PM Yonghong Song wrote: > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> On 2/5/21 11:24 AM, Arnaldo Carvalho de Melo wrote: > >>>>>>>>> Em Fri, Feb 05, 2021 at 11:10:08AM -0800, Yonghong Song escreveu: > >>>>>>>>>> On 2/5/21 11:06 AM, Sedat Dilek wrote: > >>>>>>>>>>> On Fri, Feb 5, 2021 at 7:53 PM Sedat Dilek wrote: > >>>>>>>>>>> Grepping through linux.git/tools I guess some BTF tools/libs need to > >>>>>>>>>>> know what BTF_INT_UNSIGNED is? > >>>>>>>>> > >>>>>>>>>> BTF_INT_UNSIGNED needs kernel support. Maybe to teach pahole to > >>>>>>>>>> ignore this for now until kernel infrastructure is ready. > >>>>>>>>> > >>>>>>>>> Yeah, I thought about doing that. > >>>>>>>>> > >>>>>>>>>> Not sure whether this information will be useful or not > >>>>>>>>>> for BTF. This needs to be discussed separately. > >>>>>>>>> > >>>>>>>>> Maybe search for the rationale for its introduction in DWARF. > >>>>>>>> > >>>>>>>> In LLVM, we have: > >>>>>>>> uint8_t BTFEncoding; > >>>>>>>> switch (Encoding) { > >>>>>>>> case dwarf::DW_ATE_boolean: > >>>>>>>> BTFEncoding = BTF::INT_BOOL; > >>>>>>>> break; > >>>>>>>> case dwarf::DW_ATE_signed: > >>>>>>>> case dwarf::DW_ATE_signed_char: > >>>>>>>> BTFEncoding = BTF::INT_SIGNED; > >>>>>>>> break; > >>>>>>>> case dwarf::DW_ATE_unsigned: > >>>>>>>> case dwarf::DW_ATE_unsigned_char: > >>>>>>>> BTFEncoding = 0; > >>>>>>>> break; > >>>>>>>> > >>>>>>>> I think DW_ATE_unsigned can be ignored in pahole since > >>>>>>>> the default encoding = 0. A simple comment is enough. > >>>>>>>> > >>>>>>> > >>>>>>> Yonghong Son, do you have a patch/diff for me? > >>>>>> > >>>>>> Looking at error message from log: > >>>>>> > >>>>>> LLVM_OBJCOPY=/opt/binutils/bin/objcopy /opt/pahole/bin/pahole -J > >>>>>> .tmp_vmlinux.btf > >>>>>> [115] INT DW_ATE_unsigned_1 Error emitting BTF type > >>>>>> Encountered error while encoding BTF. > >>>>>> > >>>>>> Not exactly what is the root cause. Maybe bt->bit_size is not > >>>>>> encoded correctly. Could you put vmlinux (in the above it is > >>>>>> .tmp_vmlinux.btf) somewhere, I or somebody else can investigate > >>>>>> and provide a proper fix. > >>>>>> > >>>>> > >>>>> [ TO: Masahiro ] > >>>>> > >>>>> Thanks for taking care Yonghong - hope this is your first name, if not > >>>>> I am sorry. > >>>>> In case of mixing my first and last name you will make me female - > >>>>> Dilek is a Turkish female first name :-). > >>>>> So, in some cultures you need to be careful. > >>>>> > >>>>> Anyway... back to business and facts. > >>>>> > >>>>> Out of frustration I killed my last build via `make distclean`. > >>>>> The whole day I tested diverse combination of GCC-10 and LLVM-12 > >>>>> together with BTF Kconfigs, selfmade pahole, etc. > >>>>> > >>>>> I will do ne run with some little changes: > >>>>> > >>>>> #1: Pass LLVM_IAS=1 to make (means use Clang's Integrated ASsembler - > >>>>> as per Nick this leads to the same error - should be unrelated) > >>>>> #2: I did: DEBUG_INFO_COMPRESSED y -> n > >>>>> > >>>>> #2 I did in case you need vmlinux and I have to upload - I will > >>>>> compress the resulting vmlinux with ZSTD. > >>>>> You need vmlinux or .tmp_vmlinux.btf file? > >>>>> Nick was not allowed from his company to download from a Dropbox link. > >>>>> So, as an alternative I can offer GoogleDrive... > >>>>> ...or bomb into your INBOX :-). > >>>>> > >>>>> Now, why I CCed Masahiro: > >>>>> > >>>>> In case of ERRORs when running `scripts/link-vmlinux.sh` above files > >>>>> will be removed. > >>>>> > >>>>> Last, I found a hack to bypass this - means to keep these files (I > >>>>> need to check old emails). > >>>>> > >>>>> Masahiro, you see a possibility to have a way to keep these files in > >>>>> case of ERRORs without doing hackery? > >>>>> > >>>>> From a previous post in this thread: > >>>>> > >>>>> + info BTF .btf.vmlinux.bin.o > >>>>> + [ != silent_ ] > >>>>> + printf %-7s %s\n BTF .btf.vmlinux.bin.o > >>>>> BTF .btf.vmlinux.bin.o > >>>>> + LLVM_OBJCOPY=llvm-objcopy /opt/pahole/bin/pahole -J .tmp_vmlinux.btf > >>>>> [2] INT long unsigned int Error emitting BTF type > >>>>> Encountered error while encoding BTF. > >>>>> + llvm-objcopy --only-section=.BTF --set-section-flags > >>>>> .BTF=alloc,readonly --strip-all .tmp_vmlinux.btf .btf.vmlinux.bin.o > >>>>> ... > >>>>> + info BTFIDS vmlinux > >>>>> + [ != silent_ ] > >>>>> + printf %-7s %s\n BTFIDS vmlinux > >>>>> BTFIDS vmlinux > >>>>> + ./tools/bpf/resolve_btfids/resolve_btfids vmlinux > >>>>> FAILED: load BTF from vmlinux: Invalid argument > >>>>> + on_exit > >>>>> + [ 255 -ne 0 ] > >>>>> + cleanup > >>>>> + rm -f .btf.vmlinux.bin.o > >>>>> + rm -f .tmp_System.map > >>>>> + rm -f .tmp_vmlinux.btf .tmp_vmlinux.kallsyms1 > >>>>> .tmp_vmlinux.kallsyms1.S .tmp_vmlinux.kallsyms1.o > >>>>> .tmp_vmlinux.kallsyms2 .tmp_vmlinux.kallsyms2.S .tmp_vmlinux.kallsyms > >>>>> 2.o > >>>>> + rm -f System.map > >>>>> + rm -f vmlinux > >>>>> + rm -f vmlinux.o > >>>>> make[3]: *** [Makefile:1166: vmlinux] Error 255 > >>>>> > >>>>> ^^^ Look here. > >>>>> > >>>> > >>>> With this diff: > >>>> > >>>> $ git diff scripts/link-vmlinux.sh > >>>> diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh > >>>> index eef40fa9485d..40f1b6aae553 100755 > >>>> --- a/scripts/link-vmlinux.sh > >>>> +++ b/scripts/link-vmlinux.sh > >>>> @@ -330,7 +330,7 @@ vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o} > >>>> # fill in BTF IDs > >>>> if [ -n "${CONFIG_DEBUG_INFO_BTF}" -a -n "${CONFIG_BPF}" ]; then > >>>> info BTFIDS vmlinux > >>>> - ${RESOLVE_BTFIDS} vmlinux > >>>> + ##${RESOLVE_BTFIDS} vmlinux > >>>> fi > >>>> > >>>> if [ -n "${CONFIG_BUILDTIME_TABLE_SORT}" ]; then > >>>> > >>>> This files are kept - not removed: > >>>> > >>>> $ LC_ALL=C ll .*btf* vmlinux vmlinux.o > >>>> -rwxr-xr-x 1 dileks dileks 31M Feb 6 06:37 .btf.vmlinux.bin.o > >>>> -rwxr-xr-x 1 dileks dileks 348M Feb 6 06:37 .tmp_vmlinux.btf > >>>> -rwxr-xr-x 1 dileks dileks 348M Feb 6 06:37 vmlinux > >>>> -rw-r--r-- 1 dileks dileks 344M Feb 6 06:37 vmlinux.o > >>>> > >>>> Pleas let me know where to upload - Dropbox or GoogleDrive or > >>>> elsewhere and give me a link. > >>>> > >>> > >>> > >>> WOW, ZSTD is great :-). > >>> > >>> $ zstd -19 -T0 -v vmlinux > >>> *** zstd command line interface 64-bits v1.4.8, by Yann Collet *** > >>> Note: 2 physical core(s) detected > >>> vmlinux : 22.71% (364466016 => 82784801 bytes, vmlinux.zst) > >>> > >>> $ du -m vmlinux* > >>> 348 vmlinux > >>> 79 vmlinux.zst > >>> > >> > >> Dropbox link: > >> https://www.dropbox.com/sh/kvyh8ps7na0r1h5/AABfyNfDZ2bESse_bo4h05fFa?dl=0 > >> > >> I hope this is public available. > >> > > > > Inspecting vmlinux with llvm-dwarf: > > > > $ /opt/llvm-toolchain/bin/llvm-dwarfdump vmlinux | grep DW_AT_name | > > grep DW_ATE_ | sort | uniq > > DW_AT_name ("DW_ATE_signed_1") > > DW_AT_name ("DW_ATE_signed_16") > > DW_AT_name ("DW_ATE_signed_32") > > DW_AT_name ("DW_ATE_signed_64") > > DW_AT_name ("DW_ATE_signed_8") > > DW_AT_name ("DW_ATE_unsigned_1") > > DW_AT_name ("DW_ATE_unsigned_128") > > DW_AT_name ("DW_ATE_unsigned_16") > > DW_AT_name ("DW_ATE_unsigned_24") > > DW_AT_name ("DW_ATE_unsigned_32") > > DW_AT_name ("DW_ATE_unsigned_40") > > DW_AT_name ("DW_ATE_unsigned_64") > > DW_AT_name ("DW_ATE_unsigned_8") > > > > - Sedat - > > Thanks for the above dropbot link, I am able to reproduce the issue. > > I tried to use latest llvm + Nick's patch + latest pahole + dwarf5 > config option to compile kernel with LLVM=1 LLVM_IAS=1, somehow > I did not hit the issue. It complained like > > MODPOST vmlinux.symvers > WARNING: modpost: vmlinux.o(.text+0x6ce73): Section mismatch in > reference from the function __nodes > _weight() to the variable .init.data:numa_nodes_parsed > The function __nodes_weight() references > the variable __initdata numa_nodes_parsed. > This is often because __nodes_weight lacks a __initdata > annotation or the annotation of numa_nodes_parsed is wrong. > > but otherwise compilation is fine. > > With the above vmlinux, the issue appears to be handling > DW_ATE_signed_1, DW_ATE_unsigned_{1,24,40}. > > The following patch should fix the issue: > > -bash-4.4$ git diff > > diff --git a/dwarf_loader.c b/dwarf_loader.c > > index b73d786..0341b5e 100644 > > --- a/dwarf_loader.c > > +++ b/dwarf_loader.c > > @@ -467,8 +467,16 @@ static struct base_type *base_type__new(Dwarf_Die > *die, struct cu *cu) > > > if (bt != NULL) { > > tag__init(&bt->tag, cu, die); > > - bt->name = strings__add(strings, attr_string(die, > DW_AT_name)); > - bt->bit_size = attr_numeric(die, DW_AT_byte_size) * 8; > > + const char *name = attr_string(die, DW_AT_name); > > + bt->name = strings__add(strings, name); > > + /* DW_ATE_unsigned_1 has DW_AT_byte_size == 0. > > + * specially process it. > > + */ > > + if (strcmp(name, "DW_ATE_unsigned_1") == 0) > > + bt->bit_size = 1; > > + else > > + bt->bit_size = attr_numeric(die, > DW_AT_byte_size) * 8; > + > > uint64_t encoding = attr_numeric(die, DW_AT_encoding); > bt->is_bool = encoding == DW_ATE_boolean; > bt->is_signed = encoding == DW_ATE_signed; > diff --git a/libbtf.c b/libbtf.c > index 9f76283..b5aa077 100644 > --- a/libbtf.c > +++ b/libbtf.c > @@ -367,13 +367,32 @@ static void btf_log_func_param(const struct > btf_elf *btfe, > } > } > > +/* btf requires power-of-2 bytes, yet dwarf may have something like > + * DW_ATE_unsigned_24 which encodes as 24 bits (3 bytes). > + */ > +static int bits_to_int_bytes(uint16_t bit_size) > +{ > + if (bit_size <= 8) > + return 1; > + if (bit_size <= 16) > + return 2; > + if (bit_size <= 32) > + return 4; > + if (bit_size <= 64) > > + return 8; > > + if (bit_size <= 128) > + return 16; > + /* BTF supports upto 16byte int (__int128). */ > + return -1; > +} > + > int32_t btf_elf__add_base_type(struct btf_elf *btfe, const struct > base_type *bt, > const char *name) > { > struct btf *btf = btfe->btf; > const struct btf_type *t; > uint8_t encoding = 0; > - int32_t id; > + int32_t id, nbytes; > > if (bt->is_signed) { > encoding = BTF_INT_SIGNED; > @@ -384,7 +403,13 @@ int32_t btf_elf__add_base_type(struct btf_elf > *btfe, const struct base_type *b > t, > return -1; > } > - id = btf__add_int(btf, name, BITS_ROUNDUP_BYTES(bt->bit_size), > encoding); > + nbytes = bits_to_int_bytes(bt->bit_size); > + if (nbytes < 0) { > + fprintf(stderr, "not supported bit_size %hu\n", > bt->bit_size); > + return -1; > + } > + > + id = btf__add_int(btf, name, nbytes, encoding); > if (id < 0) { > btf_elf__log_err(btfe, BTF_KIND_INT, name, true, "Error > emitting BTF type"); > } else { > -bash-4.4$ > > Please help do a test. I can submit a formal patch tomorrow. Thanks for the patch. Can you attach the diff as Gmail has totally truncated/malformed it? For the Linux breakage - you will need some additional Clang specific patches. Is this Linux 5.11-rcX? The "Blocking bugs" are listed in the first post of "Linux 5.11 release cycle". Hope this helps. This is cool co-working :-). - Sedat - [1] https://github.com/ClangBuiltLinux/linux/issues/1228