On Sat, Feb 6, 2021 at 9:32 AM Sedat Dilek wrote: > > 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 With the attached diff and new selfmade pahole looks good here. Passed (see line-numbers): 11090:+ info LD .tmp_vmlinux.btf 11099:+ info BTF .btf.vmlinux.bin.o 11103:+ LLVM_OBJCOPY=llvm-objcopy /opt/pahole/bin/pahole -J .tmp_vmlinux.btf 11121:+ info LD .tmp_vmlinux.kallsyms1 11139:+ info KSYMS .tmp_vmlinux.kallsyms1.S 11145:+ info AS .tmp_vmlinux.kallsyms1.S 11160:+ info LD .tmp_vmlinux.kallsyms2 11178:+ info KSYMS .tmp_vmlinux.kallsyms2.S 11184:+ info AS .tmp_vmlinux.kallsyms2.S 11200:+ info LD vmlinux 11210:+ info BTFIDS vmlinux 11216:+ info SORTTAB vmlinux Still building linux-kernel... Will report later if I was able to boot on bare metal. - Sedat -